WorldWideScience

Sample records for machine-tool vibration based

  1. An Investigation of Vibration Reducing on a Machine Tool

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In order to reduce the vibration on a machine tool, more orthogonal experiment schemes have been designed, which are based on the steel balls vibration reducing principle. After experiments the optimal reducing vibration scheme was determined. This kind of vibration reducing scheme is used in steel balls vibration absorber, which can be used to reduce vibration magnitudes of a machine tools under the working conditions, whereby improving machining precision. The suggested experiment method is of useful reference in reducing vibrations on other machine tools too.

  2. Adaptive Control of Machine-Tool Vibration Based on an Active Tool Holder Shank with an Embedded Piezo Ceramic Actuator

    OpenAIRE

    Pettersson, Linus; Håkansson, Lars; Claesson, Ingvar; Olsson, Sven

    2001-01-01

    In the turning operation chatter or vibration is a common problem affecting the result of the machining, and, in particular, the surface finish. Tool life is also influenced by vibration. Severe acoustic noise in the working environment frequently occurs as a result of dynamic motion between the cutting tool and the workpiece. These problems can be reduced by active control of machine-tool vibration. However, machine-tool vibration control systems are usually not applicable to a general lathe...

  3. Experimental investigation of active machine tool vibration control

    Science.gov (United States)

    Rojas, J.; Liang, Chen; Geng, Zheng J.

    1996-05-01

    The successful vibration reduction of machine tools during machining process can improve productivity, increase quality, and reduce tool wear. This paper will present our initial investigation in the application of smart material technologies in machine tool vibration control using magnetostrictive actuators and electrorheological elastomer dampers on an industrial Sheldon horizontal lathe. The dynamics of the machining process are first studied, which reveals the complexity in the machine tool vibration response and the challenge to the active control techniques. The active control experiment shows encouraging results. The use of electrorheological elastomer damping device for active/passive vibration control provides significant vibration reduction in the high frequency range and great improvement in the workpiece surface finishing. The research presented in this paper demonstrates that the combination of active and active/passive vibration control techniques is very promising for successful machine tool vibration control.

  4. NC Machine Tools Fault Diagnosis Based on Kernel PCA and k-Nearest Neighbor Using Vibration Signals

    Directory of Open Access Journals (Sweden)

    Zhou Yuqing

    2015-01-01

    Full Text Available This paper focuses on the fault diagnosis for NC machine tools and puts forward a fault diagnosis method based on kernel principal component analysis (KPCA and k-nearest neighbor (kNN. A data-dependent KPCA based on covariance matrix of sample data is designed to overcome the subjectivity in parameter selection of kernel function and is used to transform original high-dimensional data into low-dimensional manifold feature space with the intrinsic dimensionality. The kNN method is modified to adapt the fault diagnosis of tools that can determine thresholds of multifault classes and is applied to detect potential faults. An experimental analysis in NC milling machine tools is developed; the testing result shows that the proposed method is outperforming compared to the other two methods in tool fault diagnosis.

  5. Active Control of Machine-Tool Vibration in a CNC Lathe Based on an Active Tool Holder Shank with Embedded Piezo Ceramic Actuators

    OpenAIRE

    Pettersson, Linus; Håkansson, Lars; Claesson, Ingvar; Olsson, Sven

    2001-01-01

    In the turning operation chatter or vibration is a frequent problem affecting the result of the machining, and, in particular, the surface finish. Tool life is also influenced by vibration. Severe acoustic noise in the working environment frequently occurs as a result of dynamic motion between the cutting tool and the workpiece. These problems can be reduced by active control of machine-tool vibration. However, machine-tool vibration control systems are usually not applicable to a general lat...

  6. Real-Time Compensation of Chatter Vibration in Machine Tools

    Directory of Open Access Journals (Sweden)

    Dong-Hoon Kim

    2013-05-01

    Full Text Available The chatter vibration stands for a sudden relative vibration appeared between a material and a tool while processing with a machine. This vibration is a factor that seriously affects the quality of processed materials as well as being a factor which causes serious damages to the tool and the machine. This study is related to the detection and compensation of chatter vibration that can compensate chatter vibration faster and produce processed goods with more precision by autonomous compensation. The above-mentioned chatter vibration compensator includes the chatter vibration sensor and the chatter compensator that estimates the compensation value according to the sensor detecting the chatter vibration of machine tool and the chatter vibration detected from the sensor while having a feature of being organized by interlocking with the machine tool controller.

  7. Robust Control of Machine-Tool Vibration in a Lathe

    OpenAIRE

    Claesson, Ingvar; Håkansson, Lars; Lagö, Thomas L.

    1999-01-01

    In the turning operation the relative dynamic motion between cutting tool and workpiece, or vibration, is a frequent problem, which affects the result of the machining, and, in particular, the surface finish. Tool life is also influenced by vibration. Severe acoustic noise in the working environment frequently occurs as a result of dynamic motion between the cutting tool and the workpiece. These problems can be reduced substantially by active control of the machine-tool vibration. Adaptive fe...

  8. Optimization of Surface Finish in Turning Operation by Considering the Machine Tool Vibration using Taguchi Method

    Directory of Open Access Journals (Sweden)

    Muhammad Munawar

    2012-01-01

    Full Text Available Optimization of surface roughness has been one of the primary objectives in most of the machining operations. Poor control on the desired surface roughness generates non conforming parts and results into increase in cost and loss of productivity due to rework or scrap. Surface roughness value is a result of several process variables among which machine tool condition is one of the significant variables. In this study, experimentation was carried out to investigate the effect of machine tool condition on surface roughness. Variable used to represent machine tool\\'s condition was vibration amplitude. Input parameters used, besides vibration amplitude, were feed rate and insert nose radius. Cutting speed and depth of cut were kept constant. Based on Taguchi orthogonal array, a series of experimentation was designed and performed on AISI 1040 carbon steel bar at default and induced machine tool\\'s vibration amplitudes. ANOVA (Analysis of Variance, revealed that vibration amplitude and feed rate had moderate effect on the surface roughness and insert nose radius had the highest significant effect on the surface roughness. It was also found that a machine tool with low vibration amplitude produced better surface roughness. Insert with larger nose radius produced better surface roughness at low feed rate.

  9. In-process machine tool vibration cancellation using PMN actuators

    Science.gov (United States)

    Eshete, Zelalem; Zhang, Guangming

    1996-12-01

    At present, the machine tool technology in the US is not in the state-of-the-art of leading international competitors. Conventional machine tools under use are being pushed into their machining accuracy limits. There is a pressing need calling for revitalizing the machine tool industry. This paper presents, a mechatronic system developed for reducing tool vibration during machining. It consists of electrical and mechanical components, and is realized by placing electrically driven electrostrictive actuators in a specially designed tool post mechanical structure. The linear neural network controller, namely, digital filters, are implemented using a signal processing board. The experimental investigation is conducted in two stages. In the first stage, a test bed is established to use an electro-magnetic shaker to resemble the excitation of cutting force acting on the tool. In the second stage, experiments were conducted using a lathe on the shop floor. In-process vibration cancellation was observed. In the laboratory experiment, a percent reduction in the 90 percent was possible using a feedforward scheme. The improvement in surface roughness during the turning operation was confirmed from measurements of surface roughness profiles.

  10. An Approach to the Classification of Cutting Vibration on Machine Tools

    Directory of Open Access Journals (Sweden)

    Jeng-Fung Chen

    2016-02-01

    Full Text Available Predictions of cutting vibrations are necessary for improving the operational efficiency, product quality, and safety in the machining process, since the vibration is the main factor for resulting in machine faults. “Cutting vibration” may be caused by setting incorrect parameters before machining is commenced and may affect the precision of the machined work piece. This raises the need to have an effective model that can be used to predict cutting vibrations. In this study, an artificial neural network (ANN model to forecast and classify the cutting vibration of the intelligent machine tool is presented. The factors that may cause cutting vibrations is firstly identified and a dataset for the research purpose is constructed. Then, the applicability of the model is illustrated. Based on the results in the comparative analysis, the artificial neural network approach performed better than the others. Because the vibration can be forecasted and classified, the product quality can be managed. This work may help new workers to avoid operating machine tools incorrectly, and hence can decrease manufacturing costs. It is expected that this study can enhance the performance of machine tools in metalworking sectors.

  11. Active Control of Machine-Tool Vibration in a Lathe

    OpenAIRE

    Claesson, Ingvar; Håkansson, Lars

    1997-01-01

    In the turning operation the relative dynamic motion between cutting tool and workpiece, or vibration is a frequent problem, which affects the result of the machining, in particular the surface finish. The tool life is also influenced by the vibrations. When the working environment is considered, noise is frequently introduced by dynamic motion between the cutting tool and the workpiece. By proper machine design, e.g. improved stiffness of the machine structure, the problem of relative dynami...

  12. Analysis on machine tool systems using spindle vibration monitoring for automatic tool changer

    Directory of Open Access Journals (Sweden)

    Shang-Liang Chen

    2015-12-01

    Full Text Available Recently, the intelligent systems of technology have become one of the major items in the development of machine tools. One crucial technology is the machinery status monitoring function, which is required for abnormal warnings and the improvement of cutting efficiency. During processing, the mobility act of the spindle unit determines the most frequent and important part such as automatic tool changer. The vibration detection system includes the development of hardware and software, such as vibration meter, signal acquisition card, data processing platform, and machine control program. Meanwhile, based on the difference between the mechanical configuration and the desired characteristics, it is difficult for a vibration detection system to directly choose the commercially available kits. For this reason, it was also selected as an item for self-development research, along with the exploration of a significant parametric study that is sufficient to represent the machine characteristics and states. However, we also launched the development of functional parts of the system simultaneously. Finally, we entered the conditions and the parameters generated from both the states and the characteristics into the developed system to verify its feasibility.

  13. Development of Dual-Axis MEMS Accelerometers for Machine Tools Vibration Monitoring

    Directory of Open Access Journals (Sweden)

    Chih-Yung Huang

    2016-07-01

    Full Text Available With the development of intelligent machine tools, monitoring the vibration by the accelerometer is an important issue. Accelerometers used for measuring vibration signals during milling processes require the characteristics of high sensitivity, high resolution, and high bandwidth. A commonly used accelerometer is the lead zirconate titanate (PZT type; however, integrating it into intelligent modules is excessively expensive and difficult. Therefore, the micro electro mechanical systems (MEMS accelerometer is an alternative with the advantages of lower price and superior integration. In the present study, we integrated two MEMS accelerometer chips into a low-pass filter and housing to develop a low-cost dual-axis accelerometer with a bandwidth of 5 kHz and a full scale range of ±50 g for measuring machine tool vibration. In addition, a platform for measuring the linearity, cross-axis sensitivity and frequency response of the MEMS accelerometer by using the back-to-back calibration method was also developed. Finally, cutting experiments with steady and chatter cutting were performed to verify the results of comparing the MEMS accelerometer with the PZT accelerometer in the time and frequency domains. The results demonstrated that the dual-axis MEMS accelerometer is suitable for monitoring the vibration of machine tools at low cost.

  14. The Axial Nonlinear Vibration Analysis of Ball-screw about Machine Tool Feeding System

    Institute of Scientific and Technical Information of China (English)

    ZENG Hao-ran; LIU Nian-cong; YANG Jia-rui; CHEN Jian-long; GENG Wei-tao

    2016-01-01

    The forced state of the ball⁃screw of machine tool feeding system is analyzed. The ball⁃screw is simplified as Timoshenko beam and the differential equation of motion for the ball⁃screw is built. To obtain the axial vibration equation, the differential equation of motion is simplified using the assumed mode method. Axial vibration equation is in form of Duffing equation and has the characteristics of nonlinearity. The numerical simulation of Duffing equation is proceeded by MATLAB/Simulink. The effect of screw length, exciting force and damping coefficient are researched, and the axial vibration phase track diagram and Poincare section are obtained. The stability and period of the axial vibration are analyzed. The limit cycle of phase track diagram is enclosed. Axial vibration has two type⁃center singularity distributions on both sides of the origin. The singularity attracts vibration to reach a stable state, and Poincare section shows that axial vibration appears chaotic motion and quasi periodic motion or periodic motion. Singularity position changes with the vibration system parameters, while the distribution doesn′t change. The period of the vibration is enhanced with increasing frequency and damping coefficient. Test of the feeding system ball⁃screw axial vibration exists chaos movement. This paper provides a certain theoretical basis for the dynamic characteristic analysis of machine feeding system ball⁃screw and optimization of structural parameters.

  15. Research advances in coupling bionic optimization design method for CNC machine tools based on ergonomics

    Directory of Open Access Journals (Sweden)

    Shihao LIU

    2015-06-01

    Full Text Available Currently, most Chinese CNC machine tools' dynamic and static performances have large gap comparing with the similar foreign products, and the CNC machine tools users' human-centered design demand are ignored, which results in that the domestic CNC machine tools' overall competitiveness is relatively low. In order to solve the above problem, the ergonomics and coupling bionics are adopted to study collaborative optimization design method for CNC machine tools based on the domestic and foreign machine tool design method research achievement. The CNC machine tools' "man-machine-environment" interaction mechanism can be built by combining with ergonomic, and then the CNC ergonomic design criteria is obtained. Taking the coupling bionics as theoretical basis, the biological structures "morphology-structure-function-adaptive growth" multiple coupling mechanism can be studied, and the mechanical performance benefits structure can be extracted, then the CNC machine tools structural coupling bionic design technology is obtained by combining with the similarity principle. Combination of CNC machine tools' ergonomic design criteria and coupling bionic design technology, and considering the CNC machine tool performance's interaction and coupling mechanisms, a new multi-objective optimization design method can be obtained, which is verified through CNC machine tools' prototype experiments. The new optimization design method for CNC machine tools can not only help improve the whole machine's dynamic and static performance, but also has a bright prospect because of the "man-oriented" design concept.

  16. Machine tool structures

    CERN Document Server

    Koenigsberger, F

    1970-01-01

    Machine Tool Structures, Volume 1 deals with fundamental theories and calculation methods for machine tool structures. Experimental investigations into stiffness are discussed, along with the application of the results to the design of machine tool structures. Topics covered range from static and dynamic stiffness to chatter in metal cutting, stability in machine tools, and deformations of machine tool structures. This volume is divided into three sections and opens with a discussion on stiffness specifications and the effect of stiffness on the behavior of the machine under forced vibration c

  17. Method for vibration response simulation and sensor placement optimization of a machine tool spindle system with a bearing defect.

    Science.gov (United States)

    Cao, Hongrui; Niu, Linkai; He, Zhengjia

    2012-01-01

    Bearing defects are one of the most important mechanical sources for vibration and noise generation in machine tool spindles. In this study, an integrated finite element (FE) model is proposed to predict the vibration responses of a spindle bearing system with localized bearing defects and then the sensor placement for better detection of bearing faults is optimized. A nonlinear bearing model is developed based on Jones' bearing theory, while the drawbar, shaft and housing are modeled as Timoshenko's beam. The bearing model is then integrated into the FE model of drawbar/shaft/housing by assembling equations of motion. The Newmark time integration method is used to solve the vibration responses numerically. The FE model of the spindle-bearing system was verified by conducting dynamic tests. Then, the localized bearing defects were modeled and vibration responses generated by the outer ring defect were simulated as an illustration. The optimization scheme of the sensor placement was carried out on the test spindle. The results proved that, the optimal sensor placement depends on the vibration modes under different boundary conditions and the transfer path between the excitation and the response.

  18. CPS Modeling of CNC Machine Tool Work Processes Using an Instruction-Domain Based Approach

    Directory of Open Access Journals (Sweden)

    Jihong Chen

    2015-06-01

    Full Text Available Building cyber-physical system (CPS models of machine tools is a key technology for intelligent manufacturing. The massive electronic data from a computer numerical control (CNC system during the work processes of a CNC machine tool is the main source of the big data on which a CPS model is established. In this work-process model, a method based on instruction domain is applied to analyze the electronic big data, and a quantitative description of the numerical control (NC processes is built according to the G code of the processes. Utilizing the instruction domain, a work-process CPS model is established on the basis of the accurate, real-time mapping of the manufacturing tasks, resources, and status of the CNC machine tool. Using such models, case studies are conducted on intelligent-machining applications, such as the optimization of NC processing parameters and the health assurance of CNC machine tools.

  19. Effects of Machine Tool Configuration on Its Dynamics Based on Orthogonal Experiment Method

    Institute of Scientific and Technical Information of China (English)

    GAO Xiangsheng; ZHANG Yidu; ZHANG Hongwei; WU Qiong

    2012-01-01

    In order to analyze the influence of configuration parameters on dynamic characteristics of machine tools in the working space,the configuration parameters have been suggested based on the orthogonal experiment method.Dynamic analysis of a milling machine,which is newly designed for producing turbine blades,has been conducted by utilizing the modal synthesis method.The finite element model is verified and updated by experimental modal analysis (EMA) of the machine tool.The result gained by modal synthesis method is compared with whole-model finite element method (FEM) result as well.According to the orthogonal experiment method,four configuration parameters of machine tool are considered as four factors for dynamic characteristics.The influence of configuration parameters on the first three natural frequencies is obtained by range analysis.It is pointed out that configuration parameter is the most important factor affecting the fundamental frequency of machine tools,and configuration parameter has less effect on lower-order modes of the system than others.The combination of configuration parameters which makes the fundamental frequency reach the maximum value is provided.Through demonstration,the conclusion can be drawn that the influence of configuration parameters on the natural frequencies of machine tools can be analyzed explicitly by the orthogonal experiment method,which offers a new method for estimating the dynamic characteristics of machine tools.

  20. NC flame pipe cutting machine tool based on open architecture CNC system

    Institute of Scientific and Technical Information of China (English)

    Xiaogen NIE; Yanbing LIU

    2009-01-01

    Based on the analysis of the principle and flame movement of a pipe cutting machine tool, a retrofit NC flame pipe cutting machine tool (NFPCM) that can meet the demands of cutting various pipes is proposed. The paper deals with the design and implementation of an open architecture CNC system for the NFPCM, many of whose aspects are similar to milling machines; however, different from their machining processes and control strategies. The paper emphasizes on the NC system structure and the method for directly creating the NC file according to the cutting type and parameters. Further, the paper develops the program and sets up the open and module NC system.

  1. A Scheduling System Based on Rules of the Machine Tools in FMS

    Institute of Scientific and Technical Information of China (English)

    LI De-xin; ZHAO Hua-qun; JIA Jie; LU Yan-jun

    2003-01-01

    In this paper, a model of the scheduling of machine tools in the flexible manufacturing line is presented by intensive analysis and research of the mathematical method of traditional scheduling. The various factors correlative with machine tools in the flexible manufacturing line are fully considered in this system. Aiming at this model, an intelligent decision system based on rules and simulation technolo-gy integration is constructed by using the OOP ( Object-Orented Programming) method, and the simula-tion experiment analysis is carried out. It is shown from the results that the model is better in practice.

  2. An Investigation into Error Source Identification of Machine Tools Based on Time-Frequency Feature Extraction

    Directory of Open Access Journals (Sweden)

    Dongju Chen

    2016-01-01

    Full Text Available This paper presents a new identification method to identify the main errors of the machine tool in time-frequency domain. The low- and high-frequency signals of the workpiece surface are decomposed based on the Daubechies wavelet transform. With power spectral density analysis, the main features of the high-frequency signal corresponding to the imbalance of the spindle system are extracted from the surface topography of the workpiece in the frequency domain. With the cross-correlation analysis method, the relationship between the guideway error of the machine tool and the low-frequency signal of the surface topography is calculated in the time domain.

  3. Program Suite for Conceptual Designing of Parallel Mechanism-Based Robots and Machine Tools

    Directory of Open Access Journals (Sweden)

    Slobodan Tabaković

    2013-06-01

    This paper describes the categorization of criteria for the conceptual design of parallel mechanism‐based robots or machine tools, resulting from workspace analysis as well as the procedure of their defining. Furthermore, it also presents the designing methodology that was implemented into the program for the creation of a robot or machine tool space model and the optimization of the resulting solution. For verification of the criteria and the programme suite, three common (conceptually different mechanisms with a similar mechanical structure and kinematic characteristics were used.

  4. A Method to Optimize Geometric Errors of Machine Tool based on SNR Quality Loss Function and Correlation Analysis

    Directory of Open Access Journals (Sweden)

    Cai Ligang

    2017-01-01

    Full Text Available Instead improving the accuracy of machine tool by increasing the precision of key components level blindly in the production process, the method of combination of SNR quality loss function and machine tool geometric error correlation analysis to optimize five-axis machine tool geometric errors will be adopted. Firstly, the homogeneous transformation matrix method will be used to build five-axis machine tool geometric error modeling. Secondly, the SNR quality loss function will be used for cost modeling. And then, machine tool accuracy optimal objective function will be established based on the correlation analysis. Finally, ISIGHT combined with MATLAB will be applied to optimize each error. The results show that this method is reasonable and appropriate to relax the range of tolerance values, so as to reduce the manufacturing cost of machine tools.

  5. Research on Key Technologies of Unit-Based CNC Machine Tool Assembly Design

    Directory of Open Access Journals (Sweden)

    Zhongqi Sheng

    2014-01-01

    Full Text Available Assembly is the part that produces the maximum workload and consumed time during product design and manufacturing process. CNC machine tool is the key basic equipment in manufacturing industry and research on assembly design technologies of CNC machine tool has theoretical significance and practical value. This study established a simplified ASRG for CNC machine tool. The connection between parts, semantic information of transmission, and geometric constraint information were quantified to assembly connection strength to depict the assembling difficulty level. The transmissibility based on trust relationship was applied on the assembly connection strength. Assembly unit partition based on assembly connection strength was conducted, and interferential assembly units were identified and revised. The assembly sequence planning and optimization of parts in each assembly unit and between assembly units was conducted using genetic algorithm. With certain type of high speed CNC turning center, as an example, this paper explored into the assembly modeling, assembly unit partition, and assembly sequence planning and optimization and realized the optimized assembly sequence of headstock of CNC machine tool.

  6. An Integrated Approach of Fuzzy Linguistic Preference Based AHP and Fuzzy COPRAS for Machine Tool Evaluation.

    Science.gov (United States)

    Nguyen, Huu-Tho; Md Dawal, Siti Zawiah; Nukman, Yusoff; Aoyama, Hideki; Case, Keith

    2015-01-01

    Globalization of business and competitiveness in manufacturing has forced companies to improve their manufacturing facilities to respond to market requirements. Machine tool evaluation involves an essential decision using imprecise and vague information, and plays a major role to improve the productivity and flexibility in manufacturing. The aim of this study is to present an integrated approach for decision-making in machine tool selection. This paper is focused on the integration of a consistent fuzzy AHP (Analytic Hierarchy Process) and a fuzzy COmplex PRoportional ASsessment (COPRAS) for multi-attribute decision-making in selecting the most suitable machine tool. In this method, the fuzzy linguistic reference relation is integrated into AHP to handle the imprecise and vague information, and to simplify the data collection for the pair-wise comparison matrix of the AHP which determines the weights of attributes. The output of the fuzzy AHP is imported into the fuzzy COPRAS method for ranking alternatives through the closeness coefficient. Presentation of the proposed model application is provided by a numerical example based on the collection of data by questionnaire and from the literature. The results highlight the integration of the improved fuzzy AHP and the fuzzy COPRAS as a precise tool and provide effective multi-attribute decision-making for evaluating the machine tool in the uncertain environment.

  7. An Integrated Approach of Fuzzy Linguistic Preference Based AHP and Fuzzy COPRAS for Machine Tool Evaluation.

    Directory of Open Access Journals (Sweden)

    Huu-Tho Nguyen

    Full Text Available Globalization of business and competitiveness in manufacturing has forced companies to improve their manufacturing facilities to respond to market requirements. Machine tool evaluation involves an essential decision using imprecise and vague information, and plays a major role to improve the productivity and flexibility in manufacturing. The aim of this study is to present an integrated approach for decision-making in machine tool selection. This paper is focused on the integration of a consistent fuzzy AHP (Analytic Hierarchy Process and a fuzzy COmplex PRoportional ASsessment (COPRAS for multi-attribute decision-making in selecting the most suitable machine tool. In this method, the fuzzy linguistic reference relation is integrated into AHP to handle the imprecise and vague information, and to simplify the data collection for the pair-wise comparison matrix of the AHP which determines the weights of attributes. The output of the fuzzy AHP is imported into the fuzzy COPRAS method for ranking alternatives through the closeness coefficient. Presentation of the proposed model application is provided by a numerical example based on the collection of data by questionnaire and from the literature. The results highlight the integration of the improved fuzzy AHP and the fuzzy COPRAS as a precise tool and provide effective multi-attribute decision-making for evaluating the machine tool in the uncertain environment.

  8. 基于Android的机床在线无线振动监测仪研制%Development of Wireless Vibration Instrument for Machine Tool Online Based on Android

    Institute of Scientific and Technical Information of China (English)

    郑美茹

    2016-01-01

    In order to protect the safety of operators and to prevent leakage of cutting fluid, modern numercial control ( NC) ma⁃chine tool is all installed with protective cover, which makes difficulty for wiring and point allocation of sensors for online monitoring on site. Aiming at the existing problems of traditional online vibration sensor such as high power consumption, difficult in wiring and point allocation on the sealed protective cover, a wireless vibration instrument based on the Android system and CC2540 single chip micro⁃computer was developed. The wireless transmission and online parametric setup of measurement, real time data display and storage functions were achieved by the measuring instrument combined with Android system and Bluetooth. The wiring problem of sensors was effectively solved by wireless transmission. The pretreatment and collection of vibration signal were completed by the measuring modules with CC2540 as central control unit, which was embedded with Bluetooth modules at low power consumption and the Android system to implement the communication of full⁃duplex communication, to save data in TF card or in cloud hosting. The actual tests show that the instrument can be used to accurately measure the vibration acceleration signal, and can be used to accurately send and receive data through the Bluetooth modules and Android mobile phone, which is convenient, simple operation and also good in application prospect. It provides reference for development of other new types of wireless measuring instrument.%为保护操作者的安全、防止切削液的外漏等,现代数控机床都安装了防护罩壳,这给现场在线监测的传感器布线、布点造成了困难。针对传统有线振动传感器在密闭防护罩壳内存在布线、布点困难和功耗高等问题,研制基于Android系统和CC2540单片机的无线振动测量仪。通过Android 系统和蓝牙实现了仪器的在线参数设置和无线传输、实时数

  9. An Approach to the Classification of Cutting Vibration on Machine Tools

    OpenAIRE

    Jeng-Fung Chen; Shih-Kuei Lo; Quang Hung Do

    2016-01-01

    Predictions of cutting vibrations are necessary for improving the operational efficiency, product quality, and safety in the machining process, since the vibration is the main factor for resulting in machine faults. “Cutting vibration” may be caused by setting incorrect parameters before machining is commenced and may affect the precision of the machined work piece. This raises the need to have an effective model that can be used to predict cutting vibrations. In this study, an artificial neu...

  10. A new damage diagnosis approach for NC machine tools based on hybrid Stationary subspace analysis

    Science.gov (United States)

    Gao, Chen; Zhou, Yuqing; Ren, Yan

    2017-05-01

    This paper focused on the damage diagnosis for NC machine tools and put forward a damage diagnosis method based on hybrid Stationary subspace analysis (SSA), for improving the accuracy and visibility of damage identification. First, the observed single sensor signal was reconstructed to multi-dimensional signals by the phase space reconstruction technique, as the inputs of SSA. SSA method was introduced to separate the reconstructed data into stationary components and non-stationary components without the need for independency and prior information of the origin signals. Subsequently, the selected non-stationary components were analysed for training LS-SVM (Least Squares Support Vector Machine) classifier model, in which several statistic parameters in the time and frequency domains were exacted as the sample of LS-SVM. An empirical analysis in NC milling machine tools is developed, and the result shows high accuracy of the proposed approach.

  11. Adaptive Active Control of Machine-Tool Vibration In a Lathe

    OpenAIRE

    Claesson, Ingvar; Håkansson, Lars

    1998-01-01

    In the turning operation the relative dynamic motion between cutting tool and workpiece, or vibration, is a frequent problem, which affects the result of the machining, and in particular, the surface finish. Tool life is also influenced by vibration. Noise in the working environment frequently occurs as a result of dynamic motion between the cutting tool and the workpiece. With proper machine design, i.e. improved stiffness of the machine structure, the problem of relative dynamic motion betw...

  12. Design of piezo-based AVC system for machine tool applications

    Science.gov (United States)

    Aggogeri, F.; Al-Bender, F.; Brunner, B.; Elsaid, M.; Mazzola, M.; Merlo, A.; Ricciardi, D.; de la O Rodriguez, M.; Salvi, E.

    2013-03-01

    The goal of machine tools for Ultra High Precision Machining is to guarantee high specified performances and to maintain them over life cycle time. In this paper the design of an innovative mechatronic subsystem (platform) for Active Vibration Control (AVC) of Ultra High Precision micromilling Machines is presented. The platform integrates piezoelectric stack actuators and a novel sensor concept. During the machining process (e.g. milling), the contact between the cutting tool and the workpiece surface at the tool tip point generates chattering vibrations. Any vibration is recorded on the workpiece surface, directly affecting its roughness. Consequently, uncontrolled vibrations lead to poor surface finishing, unacceptable in high precision milling. The proposed Smart Platform aims to improve the surface finishing of the workpiece exploiting a broadband AVC strategy. The paper describes the steps throughout the design phase of the platform, beginning from the actuator/sensor criteria selection taking into account both performance and durability. The novel actuation principle and mechanism and the related FE analysis are also presented. Finally, an integrated mechatronic model able to predict in closed-loop the active damping and vibration-suppression capability of the integrated system is presented and simulation results are discussed.

  13. Chatter and machine tools

    CERN Document Server

    Stone, Brian

    2014-01-01

    Focussing on occurrences of unstable vibrations, or Chatter, in machine tools, this book gives important insights into how to eliminate chatter with associated improvements in product quality, surface finish and tool wear. Covering a wide range of machining processes, including turning, drilling, milling and grinding, the author uses his research expertise and practical knowledge of vibration problems to provide solutions supported by experimental evidence of their effectiveness. In addition, this book contains links to supplementary animation programs that help readers to visualise the ideas detailed in the text. Advancing knowledge in chatter avoidance and suggesting areas for new innovations, Chatter and Machine Tools serves as a handbook for those desiring to achieve significant reductions in noise, longer tool and grinding wheel life and improved product finish.

  14. Fourier transform based dynamic error modeling method for ultra-precision machine tool

    Science.gov (United States)

    Chen, Guoda; Liang, Yingchun; Ehmann, Kornel F.; Sun, Yazhou; Bai, Qingshun

    2014-08-01

    In some industrial fields, the workpiece surface need to meet not only the demand of surface roughness, but the strict requirement of multi-scale frequency domain errors. Ultra-precision machine tool is the most important carrier for the ultra-precision machining of the parts, whose errors is the key factor to influence the multi-scale frequency domain errors of the machined surface. The volumetric error modeling is the important bridge to link the relationship between the machine error and machined surface error. However, the available error modeling method from the previous research is hard to use to analyze the relationship between the dynamic errors of the machine motion components and multi-scale frequency domain errors of the machined surface, which plays the important reference role in the design and accuracy improvement of the ultra-precision machine tool. In this paper, a fourier transform based dynamic error modeling method is presented, which is also on the theoretical basis of rigid body kinematics and homogeneous transformation matrix. A case study is carried out, which shows the proposed method can successfully realize the identical and regular numerical description of the machine dynamic errors and the volumetric errors. The proposed method has strong potential for the prediction of the frequency domain errors on the machined surface, extracting of the information of multi-scale frequency domain errors, and analysis of the relationship between the machine motion components and frequency domain errors of the machined surface.

  15. Thermal Error Modeling of the CNC Machine Tool Based on Data Fusion Method of Kalman Filter

    Directory of Open Access Journals (Sweden)

    Haitong Wang

    2017-01-01

    Full Text Available This paper presents a modeling methodology for the thermal error of machine tool. The temperatures predicted by modified lumped-mass method and the temperatures measured by sensors are fused by the data fusion method of Kalman filter. The fused temperatures, instead of the measured temperatures used in traditional methods, are applied to predict the thermal error. The genetic algorithm is implemented to optimize the parameters in modified lumped-mass method and the covariances in Kalman filter. The simulations indicate that the proposed method performs much better compared with the traditional method of MRA, in terms of prediction accuracy and robustness under a variety of operating conditions. A compensation system is developed based on the controlling system of Siemens 840D. Validated by the compensation experiment, the thermal error after compensation has been reduced dramatically.

  16. Study of geometric errors detection method for NC machine tools based on non-contact circular track

    Science.gov (United States)

    Yan, Kejun; Liu, Jun; Gao, Feng; Wang, Huan

    2008-12-01

    This paper presents a non-contact measuring method of geometric errors for NC machine tools based on circular track testing method. Let the machine spindle move along a circular path, the position error of every tested position in the circle can be obtained using two laser interferometers. With a volumetric error model, the 12 components of geometric error apart from angular error components can be derived. It has characteristics of wide detection range and high precision. Being obtained geometric errors respectively, it is of great significance for the error compensation of NC machine tools. This method has been tested on a MCV-510 NC machine tool. The experiment result has been proved to be feasible for this method.

  17. Universal geometric error modeling of the CNC machine tools based on the screw theory

    Science.gov (United States)

    Tian, Wenjie; He, Baiyan; Huang, Tian

    2011-05-01

    The methods to improve the precision of the CNC (Computerized Numerical Control) machine tools can be classified into two categories: error prevention and error compensation. Error prevention is to improve the precision via high accuracy in manufacturing and assembly. Error compensation is to analyze the source errors that affect on the machining error, to establish the error model and to reach the ideal position and orientation by modifying the trajectory in real time. Error modeling is the key to compensation, so the error modeling method is of great significance. Many researchers have focused on this topic, and proposed many methods, but we can hardly describe the 6-dimensional configuration error of the machine tools. In this paper, the universal geometric error model of CNC machine tools is obtained utilizing screw theory. The 6-dimensional error vector is expressed with a twist, and the error vector transforms between different frames with the adjoint transformation matrix. This model can describe the overall position and orientation errors of the tool relative to the workpiece entirely. It provides the mathematic model for compensation, and also provides a guideline in the manufacture, assembly and precision synthesis of the machine tools.

  18. Research on Remote Video Monitoring System Used for Numerical Control Machine Tools Based on Embedded Technology

    Institute of Scientific and Technical Information of China (English)

    LIU Quan; QU Xuehong; ZHOU Henglin; LONG Yihong

    2006-01-01

    This paper designed an embedded video monitoring system using DSP(Digital Signal Processing) and ARM(Advanced RISC Machine). This system is an important part of self-service operation of numerical control machine tools. At first the analog input signals from the CCD(Charge Coupled Device) camera are transformed into digital signals, and then output to the DSP system, where the video sequence is encoded according to the new generation image compressing standard called H.264. The code will be transmitted to the ARM system through xBus, and then be packed in the ARM system and transmitted to the client port through the gateway. Web technology, embedded technology and image compressing as well as coding technology are integrated in the system, which can be widely used in self-service operation of numerical control machine tools and intelligent robot control areas.

  19. Analysis of the Thermal Characteristics of Machine Tool Feed System Based on Finite Element Method

    Science.gov (United States)

    Mao, Xiaobo; Mao, Kuanmin; Du, Yikang; Wang, Fengyun; Yan, Bo

    2017-09-01

    The loading of mobile heat source and boundary conditions setting are difficult problems in the analysis of thermal characteristics of machine tools. Taking the machine tool feed system as an example, a novel method for loading of mobile heat source was proposed by establishing a function which was constructed by the heat source and time. The convective heat transfer coefficient is the key parameter of boundary conditions, and it varies with the temperature. In this paper, a model of “variable convection heat transfer coefficient” was proposed, and the setting of boundary conditions of thermal analysis was closer to the real situation. Finally, comparing results of above method and experimental data, the accuracy and validity of this method was proved, meanwhile, the simulation calculation and simulation time was reducing greatly.

  20. Market structure, industrial organisation and technological development: the case of the Japanese electronics-based nc-machine tool industry.

    OpenAIRE

    Watanabe, S

    1983-01-01

    ILO pub-WEP pub. Working paper on the impact of market structure and business organization on technological change in the automatic control machine tool industry in Japan - based on a 1982 sample survey of 40 industrial enterprises, discusses research and development trends, demand, production, subcontracting, competition, etc.; investigates the impact of electronics Innovation on small scale industry, the international division of labour and on developing countries. Bibliography and graphs.

  1. Quality characteristic association analysis of computer numerical control machine tool based on meta-action assembly unit

    Directory of Open Access Journals (Sweden)

    Yan Ran

    2016-01-01

    Full Text Available As everyone knows, assembly quality plays a very important role in final product quality. Since computer numerical control machine tool is a large system with complicated structure and function, and there are complex association relationships among quality characteristics in assembly process, then it is difficult and inaccurate to analyze the whole computer numerical control machine tool quality characteristic association at one time. In this article, meta-action assembly unit is proposed as the basic analysis unit, of which quality characteristic association is studied to guarantee the whole computer numerical control machine tool assembly quality. First, based on “Function-Motion-Action” decomposition structure, the definitions of meta-action and meta-action assembly unit are introduced. Second, manufacturing process association and meta-action assembly unit quality characteristic association are discussed. Third, after understanding the definitions of information entropy and relative entropy, the concrete meta-action assembly unit quality characteristic association analysis steps based on relative entropy are described in detail. And finally, the lifting piston translation assembly unit of automatic pallet changer is taken as an example, the association degree between internal leakage and the influence factors of part quality characteristics and mate-relationships among them are calculated to figure out the most influential factors, showing the correctness and feasibility of this method.

  2. The monitoring of transient regimes on machine tools based on speed, acceleration and active electric power absorbed by motors

    Science.gov (United States)

    Horodinca, M.

    2016-08-01

    This paper intend to propose some new results related with computer aided monitoring of transient regimes on machine-tools based on the evolution of active electrical power absorbed by the electric motor used to drive the main kinematic chains and the evolution of rotational speed and acceleration of the main shaft. The active power is calculated in numerical format using the evolution of instantaneous voltage and current delivered by electrical power system to the electric motor. The rotational speed and acceleration of the main shaft are calculated based on the signal delivered by a sensor. Three real-time analogic signals are acquired with a very simple computer assisted setup which contains a voltage transformer, a current transformer, an AC generator as rotational speed sensor, a data acquisition system and a personal computer. The data processing and analysis was done using Matlab software. Some different transient regimes were investigated; several important conclusions related with the advantages of this monitoring technique were formulated. Many others features of the experimental setup are also available: to supervise the mechanical loading of machine-tools during cutting processes or for diagnosis of machine-tools condition by active electrical power signal analysis in frequency domain.

  3. A defect-driven diagnostic method for machine tool spindles.

    Science.gov (United States)

    Vogl, Gregory W; Donmez, M Alkan

    2015-01-01

    Simple vibration-based metrics are, in many cases, insufficient to diagnose machine tool spindle condition. These metrics couple defect-based motion with spindle dynamics; diagnostics should be defect-driven. A new method and spindle condition estimation device (SCED) were developed to acquire data and to separate system dynamics from defect geometry. Based on this method, a spindle condition metric relying only on defect geometry is proposed. Application of the SCED on various milling and turning spindles shows that the new approach is robust for diagnosing the machine tool spindle condition.

  4. Error compensation on precision machine tool servo control system based on digital concave filter

    Institute of Scientific and Technical Information of China (English)

    王立松; 苏宝库; 张晶; 董申

    2001-01-01

    It is concluded from the results of testing the frequency characteristics of the sub-micron precision machine tool servo control system, that the existence of several oscillating modalities is the main factor that affects the performance of the control system. To compensate for this effect, several concave filters are utilized in the system to improve the control accuracy. The feasibility of compensating for several oscillating modalities with a single concave filter is also studied. By applying a modified Butterworth concave filter to the practical system, the maximum stable state output error remains under + 10 nm in the closed-loop positioning system.

  5. Prediction of Machine Tool Condition Using Support Vector Machine

    Science.gov (United States)

    Wang, Peigong; Meng, Qingfeng; Zhao, Jian; Li, Junjie; Wang, Xiufeng

    2011-07-01

    Condition monitoring and predicting of CNC machine tools are investigated in this paper. Considering the CNC machine tools are often small numbers of samples, a condition predicting method for CNC machine tools based on support vector machines (SVMs) is proposed, then one-step and multi-step condition prediction models are constructed. The support vector machines prediction models are used to predict the trends of working condition of a certain type of CNC worm wheel and gear grinding machine by applying sequence data of vibration signal, which is collected during machine processing. And the relationship between different eigenvalue in CNC vibration signal and machining quality is discussed. The test result shows that the trend of vibration signal Peak-to-peak value in surface normal direction is most relevant to the trend of surface roughness value. In trends prediction of working condition, support vector machine has higher prediction accuracy both in the short term ('One-step') and long term (multi-step) prediction compared to autoregressive (AR) model and the RBF neural network. Experimental results show that it is feasible to apply support vector machine to CNC machine tool condition prediction.

  6. Identification of geometric deviations inherent to multi-axis machine tools based on the pose measurement principle

    Science.gov (United States)

    Haitao, Li; Junjie, Guo; Yufen, Deng; Jindong, Wang; Xinrong, He

    2016-12-01

    The laser tracker is an effective instrument for measuring 3D relative displacement in a work volume because its attitude can be freely changed. This paper presents a novel principle to realize the precise calibration of a numerical control (NC) machine tool accurately and quickly; this is the ‘pose measurement principle’, for measuring errors. We also introduce an algorithm for identifying geometric deviations. A NC precise table mounted on a motion axis and a laser tracker are used for the coordinate determination of three fixed points to obtain the pose information of each motion axis, then calculate the pose deviations, and finally identify all the errors. For the error identification, first, according to the definition of geometric errors, we extend the concept of pose deviations, and represent the six geometric errors using a position deviation vector and attitude deviation vector. Next, we geometrically identify the three angular errors and linear errors in order; the error mathematical model for the linear axis and rotary axis are developed, respectively. Moreover, the validity of the calibration algorithm for the base station, measuring points and identification of errors are confirmed by simulations. In the end, the proposed method is applied to a three-axis NC milling machine tool and a rotary table, and then the geometric deviations are identified successfully in 3 h and 2.5 h, respectively. Comparative experiments by means of other instruments also agree well with the proposed method. Thus, the proposed method can be applied to the measurement of the multi-axis machine tool.

  7. Structural bionic design for high——speed machine tool working table based on distribution rules of leaf veins

    Institute of Scientific and Technical Information of China (English)

    XING DengHai; CHEN WuYi; ZHAO Ling; MA JianFeng

    2012-01-01

    High-speed machine tool working table restrains the machining accuracy and machining efficiency,so lightweight design of the table is an important issue.In nature,leaf has developed a plate structure that maximizes the surface-to-volume ratio.It can be seen as a plate structure stiffened by veins.Compared with a high-speed machine tool working table,leaf veins play a role of supporting part which is similar to that of stiffening ribs,and they can provide some new design ideas for lightweight design of the table.In this paper,distribution rules of leaf veins were investigated,and a structural bionic design for the table was achieved based on regulation of leaf veins.First,statistical analysis on geometric structure of leaf veins was carried out,and four distribution rules were obtained.Then,relevant mechanical models were developed and analyzed in finite element soft-ware.Based on the results from mechanical analysis on those relevant models,the four distribution rules were translated into the design rules and a structural bionic design for the working table was achieved.Both simulation and experimental verifications were carried out,and results showed that the average displacement of the working table was reduced by about 33.9%.

  8. EVALUATION OF MACHINE TOOL QUALITY

    Directory of Open Access Journals (Sweden)

    Ivan Kuric

    2011-12-01

    Full Text Available Paper deals with aspects of quality and accuracy of machine tools. As the accuracy of machine tools has key factor for product quality, it is important to know the methods for evaluation of quality and accuracy of machine tools. Several aspects of diagnostics of machine tools are described, such as aspects of reliability.

  9. Online machining error estimation method of numerical control gear grinding machine tool based on data analysis of internal sensors

    Science.gov (United States)

    Zhao, Fei; Zhang, Chi; Yang, Guilin; Chen, Chinyin

    2016-12-01

    This paper presents an online estimation method of cutting error by analyzing of internal sensor readings. The internal sensors of numerical control (NC) machine tool are selected to avoid installation problem. The estimation mathematic model of cutting error was proposed to compute the relative position of cutting point and tool center point (TCP) from internal sensor readings based on cutting theory of gear. In order to verify the effectiveness of the proposed model, it was simulated and experimented in gear generating grinding process. The cutting error of gear was estimated and the factors which induce cutting error were analyzed. The simulation and experiments verify that the proposed approach is an efficient way to estimate the cutting error of work-piece during machining process.

  10. Machine Tool Software

    Science.gov (United States)

    1988-01-01

    A NASA-developed software package has played a part in technical education of students who major in Mechanical Engineering Technology at William Rainey Harper College. Professor Hack has been using (APT) Automatically Programmed Tool Software since 1969 in his CAD/CAM Computer Aided Design and Manufacturing curriculum. Professor Hack teaches the use of APT programming languages for control of metal cutting machines. Machine tool instructions are geometry definitions written in APT Language to constitute a "part program." The part program is processed by the machine tool. CAD/CAM students go from writing a program to cutting steel in the course of a semester.

  11. Rigidity FEA of cantilever of abrasive water jet machine tool based on ANSYS%基于ANSYS磨料水射流机床悬臂梁刚度的有限元分析

    Institute of Scientific and Technical Information of China (English)

    杜文正; 雷玉勇; 李劲松; 杨振; 郭逸伟

    2012-01-01

    目前二维半磨料水射流机床大多采用悬臂梁结构。悬臂梁是磨料水射流切割头及其附件的重要承载部件,其刚度直接影响机床的加工精度。针对磨料水射流机床的悬臂梁进行了三维建模,并基于ANSYS对其进行了模态和频率响应分析。分析的结果为磨料水射流机床的减振、防振提供了理论依据。%The cantilever structure was used in most abrasive water jet machine tools.The cantilever is an important component supporting the abrasive water jet cutting head as well as other accessories.Its rigidity directly affects the machining accuracy.A 3D model of the cantilever of the abrasive water jet machine tool was established,and modal analysis and frequency response analysis were carried out based on ANSYS.The analysis results offered theoretical references for vibration reduction and prevention of the abrasive water jet machine tool.

  12. Attaching Chuck Keys to Machine Tools

    Science.gov (United States)

    Richardson, V.

    1984-01-01

    Chuck keys attached to portable machine tools by retracting lanyards. Lanyard held taut by recoil caddy attached to tool base. Chuck key available for use when needed and safely secured during operation of tool.

  13. 基于NX的组合机床智能化设计系统开发%Development of NX Based Intelligent Design System for Modular Machine Tools

    Institute of Scientific and Technical Information of China (English)

    陈青; 李青祝

    2013-01-01

    On the basis of study of design procedure,a framework of intelligent design system of modular machine tools was pro-posed. With the NX based intelligent design system of modular machine tools,and assistant of its design wizard supported by knowl-edge base and inference machine,designers could build parameterized control structure of modular machine tools,perform calculations of modular machine tool design,and create digital prototypes based on the parameterized models in database,according to customer re-quirements. As a result,high quality design can be made to meet market requirement swiftly.%在研究组合机床设计流程的基础上,提出组合机床智能化设计系统的框架。在NX平台上开发组合机床智能化设计系统,设计人员可依据客户需求,按照设计向导在知识库、推理机等的支撑下,建立组合机床的参数化控制结构,完成组合机床的设计计算,并调用数据库中的参数化模型,创建数字化样机,实现高质量的设计,快速满足市场需求。

  14. Automatically-Programed Machine Tools

    Science.gov (United States)

    Purves, L.; Clerman, N.

    1985-01-01

    Software produces cutter location files for numerically-controlled machine tools. APT, acronym for Automatically Programed Tools, is among most widely used software systems for computerized machine tools. APT developed for explicit purpose of providing effective software system for programing NC machine tools. APT system includes specification of APT programing language and language processor, which executes APT statements and generates NC machine-tool motions specified by APT statements.

  15. Automatically-Programed Machine Tools

    Science.gov (United States)

    Purves, L.; Clerman, N.

    1985-01-01

    Software produces cutter location files for numerically-controlled machine tools. APT, acronym for Automatically Programed Tools, is among most widely used software systems for computerized machine tools. APT developed for explicit purpose of providing effective software system for programing NC machine tools. APT system includes specification of APT programing language and language processor, which executes APT statements and generates NC machine-tool motions specified by APT statements.

  16. Measurement of Temperature Field for the Spindle of Machine Tool Based on Optical Fiber Bragg Grating Sensors

    Directory of Open Access Journals (Sweden)

    Mingyao Liu

    2013-01-01

    Full Text Available The change of spindle temperature field is an important factor which influences machining precision. Many methods of spindle temperature field measurement have been proposed. However, most of the methods are based on the electric temperature sensors. There exist some defects (e.g., anti-interference, multiplexing, and stability capacity are poor. To increase the temperature sensitivity and reduce strain sensitivity of the bare Fiber Bragg Grating (FBG sensor, a cassette packaged FBG sensor is proposed to measure spindle temperature field. The temperature characteristics of the packaged FBG sensor are studied by comparative experiment with traditional thermal resistor sensor. The experimental results show that the packaged FBG sensor has the same capacity of temperature measurement with the thermal resistor sensor but with more remarkable antiinterference. In the further measurement experiment of the temperature field, a spindle nonuniform temperature field is acquired by the calibrated FBG sensors. It indicates that the packaged FBG sensor can be used to measure the temperature field for the spindle of machine tool.

  17. Repurposing mainstream CNC machine tools for laser-based additive manufacturing

    Science.gov (United States)

    Jones, Jason B.

    2016-04-01

    The advent of laser technology has been a key enabler for industrial 3D printing, known as Additive Manufacturing (AM). Despite its commercial success and unique technical capabilities, laser-based AM systems are not yet able to produce parts with the same accuracy and surface finish as CNC machining. To enable the geometry and material freedoms afforded by AM, yet achieve the precision and productivity of CNC machining, hybrid combinations of these two processes have started to gain traction. To achieve the benefits of combined processing, laser technology has been integrated into mainstream CNC machines - effectively repurposing them as hybrid manufacturing platforms. This paper reviews how this engineering challenge has prompted beam delivery innovations to allow automated changeover between laser processing and machining, using standard CNC tool changers. Handling laser-processing heads using the tool changer also enables automated change over between different types of laser processing heads, further expanding the breadth of laser processing flexibility in a hybrid CNC. This paper highlights the development, challenges and future impact of hybrid CNCs on laser processing.

  18. Dynamic Characteristics Analysis of Parallel Machine Tool Based on Virtual Prototyping%基于虚拟样机技术的并联机床动态特性分析

    Institute of Scientific and Technical Information of China (English)

    李兴山; 蔡光起

    2011-01-01

    This paper introduced the 2TPT-PTT parallel machine tool based on Steward mechanism.By using of the virtual prototyping technology, the dynamic model is set up in Solideworks and Workbench.Study on the dynamic characteristic of the movement chain by finite element method and the six orders inherent frequency and vibration shape are acquired.The resonance frequency of mechanism is calculated by the analysis of the harmonic response.The result indicates that the resonance frequency of parallel machine tools is between 170 Hz and 180 Hz and the poles of the parallel mechanism is the weakness parts, so it can provide the theory basis for the optimization design of parallel machine tools.%介绍了一种基于Steward平台的2TPT-PTT并联机床构型.利用虚拟样机技术, 在Solidewroks和Workbench的环境下,建立了2TPT-PTT并联机床的动态模型.运用有限元法对机构的运动分支的动态特性进行了研究,获得了其六阶固有频率及相应的振型.通过机构的谐响应分析,求解了机构的共振频率.研究结果表明:整个机构在170~180 Hz易产生共振,平行机构的连杆为其薄弱环节,为并联机床的优化设计提供了理论依据.

  19. Development of non-contact structural health monitoring system for machine tools

    Directory of Open Access Journals (Sweden)

    Deepam Goyal

    2016-08-01

    Full Text Available In this era of flexible manufacturing systems, a real-time structural health monitoring (SHM is paramount for machining processes which are of great relevance today, when there is a constant call for better productivity with high quality at low price. During machining, vibrations are always brought forth because of mechanical disturbances from various sources such as an engine, a sound, and noise, among others. A SHM system provides significant economic benefits when applied to machine tools and machining processes. This study demonstrates a non contact SHM system for machine tools based on the vibration signal collected through a low-cost, microcontroller based data acquisition system. The examination tests of this developed system have been carried out on a vibration rig. The readings have also been calibrated with the accelerometer to validate the proposed system. The developed system results in quick measurement, enables reliable monitoring, and is cost effective with no need to alter the structure of the machine tool. It is expected that the system can forewarn the operator for timely based maintenance actions in addition to reducing the costs of machine downtime and acquiring equipments with reduction in complexity of machine tools.

  20. 基于机床做功量的监控系统开发%Development of Monitoring System Based on the Work Load of Machine Tool

    Institute of Scientific and Technical Information of China (English)

    李平; 黄泽森

    2013-01-01

    在分析机床维护保养不良是影响机床可靠性的关键因素的基础上,将一种新的可靠性思想——用户监控维护方法引入数控机床可靠性研究领域中.提出了机床定功维护的概念,并以丝杆螺母副维护保养为例,建立了丝杆螺母副与电机做功关系的数学模型.给出了主轴电机功率的获取方法,并通过对数控系统西门子840D进行二次编程,开发了基于用户角度来提高机床可靠性的用户监控维护系统.该系统在数控机床上的成功应用为机床可靠性的研究提供了一种新的思路和方法.%On the basis of poor maintenance of NC machine tool is the key factor of influencing the machine tool reliability, a new method which called User Monitor and Maintenance was introduced, and a creational concept of maintenance based on work to the field of NC machine reliability research was put forward. By the example of maintenance of ball screw and nut, the math model between the ball screw and nut, and the work of electromotor was established. The method of obtaining power of main spindle motor was given, and the System of User Monitor and Maintenance based on secondary development of NC Simens 840D system by users to improve the reliability of NC machine tool was developed. The successful application of the system on the NC machine tool provides a new method and idea for the research of NC machine tool's reliability.

  1. SDM applications to machine tools and engines

    Indian Academy of Sciences (India)

    A Sestieri

    2000-06-01

    The method of structural dynamic optimization is applied here to two real-life structures, a small two-cylinder, air-cooled gasoline engine and a high speed machine tool. The aim of the first application isthe reduction of the kinematic vibration transmission path composed of a piston-connecting rod, a crankshaft and an engine block, while the goal of the second application is the lowering of the peaks of the spindle-drive point FRFs measured along two orthogonal directions.It is shown how the addition of a small amount of mass at a few points on the engine block, and a small dynamic absorber with highly damped elastic connections provides the required improvements for the engine and the machine tool respectively.

  2. Hinged Shields for Machine Tools

    Science.gov (United States)

    Lallande, J. B.; Poland, W. W.; Tull, S.

    1985-01-01

    Flaps guard against flying chips, but fold away for tool setup. Clear plastic shield in position to intercept flying chips from machine tool and retracted to give operator access to workpiece. Machine shops readily make such shields for own use.

  3. Machine Tool Series. Duty Task List.

    Science.gov (United States)

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This task list is intended for use in planning and/or evaluating a competency-based course to prepare machine tool, drill press, grinding machine, lathe, mill, and/or power saw operators. The listing is divided into six sections, with each one outlining the tasks required to perform the duties that have been identified for the given occupation.…

  4. 基于B/S的组合机床设计系统开发%Combination Machine TOOL System Based On B/S Model

    Institute of Scientific and Technical Information of China (English)

    郭志强; 李月琴

    2011-01-01

    Taking PRO/E、SQL2005 database and VS.net programming software as developing flat, using the important tools of TOP-DOWN designing methods,setting up the parametric 3D modeling module database combination machine tool system based on B/S model is developed.Under the guiding of the combination of machine tool system, users can complete such tasks as module choice, the driving force transmission device' s power calculation, module auto-assembly, and automatically generate two-dimensional drawings, etc.Therefore, combination machine tool design System can be realized, improving the design efficiency,shorten the product design cycle and reduced the cost of production.%利用PRO/E软件、SQL2005数据库和VS.net编程软件为开发平台,采用Top-Down技术,建立了组合机床的参数化三维模型图库并开发了基于B/S的组合机床异地设计系统.用户通过浏览器在组合机床设计系统的引导下可完成对组合机床设计的动力头功率计算模块、自动匹配组合机床模块、自动装配、生成三图一卡等总体设计和主轴箱等模块的详细设计,提高了产品的开发能力,缩短了产品的设计周期,降低了生产成本.

  5. Applying TRIZ and Fuzzy AHP Based on Lean Production to Develop an Innovative Design of a New Shape for Machine Tools

    Directory of Open Access Journals (Sweden)

    Ho-Nien Hsieh

    2015-03-01

    Full Text Available Companies are facing cut throat competition and are forced to continuously perform better than their competitors. In order to enhance their position in the competitive world, organizations are improving at a faster pace. Industrial organizations must be used to the new ideals, such as innovation. Today, innovative design in the development of new products has become a core value in most companies, while innovation is recognized as the main driving force in the market. This work applies the Russian theory of inventive problem-solving, TRIZ and the fuzzy analytical hierarchy process (FAHP to design a new shape for machine tools. TRIZ offers several concepts and tools to facilitate concept creation and problem-solving, while FAHP is employed as a decision support tool that can adequately represent qualitative and subjective assessments under the multiple criteria decision-making environment. In the machine tools industry, this is the first study to develop an innovative design under the concept of lean production. We used TRIZ to propose the relevant principles to the shape’s design with the innovative design consideration and also used FAHP to evaluate and select the best feasible alternative from independent factors based on a multiple criteria decision-making environment. To develop a scientific method based on the lean production concept in order to design a new product and improve the old designing process is the contribution of this research.

  6. Machine Tool Operation, Course Description.

    Science.gov (United States)

    Denny, Walter E.; Anderson, Floyd L.

    Prepared by an instructor and curriculum specialists, this course of study was designed to meet the individual needs of the dropout and/or hard-core unemployed youth by providing them skill training, related information, and supportive services knowledge in machine tool operation. The achievement level of each student is determined at entry, and…

  7. ADAPTABLE DESIGN OF MACHINE TOOLS STRUCTURES

    Institute of Scientific and Technical Information of China (English)

    XU Yanshen; CHEN Yongliang; ZHANG Guojun; GU Peihua

    2008-01-01

    Adaptable design aims to extend the utilities of design and product. The specific methods are developed for practical applications of adaptable design in the design of mechanical structures, including adaptable platform, interface and module designs. Adaptable redesign problems are formulated as adaptable platform design under adaptability bound constraints. Analysis tools are then suggested for the implementation of the redesign of machine tool structures, including variation techniques based sensitivity analysis, similarity-based commonality analysis, performance improvement, and adaptability measures. The specific measure of adaptability for machine tool structures is measured through the quantification of the structural similarity and performance improvement gained from adaptable design. The method provides designers with an approach that brings adaptability into the design process, with considering the cost and benefits of such adaptability. The redesign of CNC spiral bevel gear cutting machine structures has been included to illustrate these concepts and methods.

  8. Static and Dynamic Performance Improvement of Conventional Computer Numerical Control Machine Tool Bed with Hybrid Welded Steel

    OpenAIRE

    S. S. Abuthakeer; P. V. Mohanram; G. Mohankumar

    2011-01-01

    Problem statement: The advancements in machine tools to maximize the production by increasing spindle speeds have caused vibration in machine tools. The two functional requirements of machine tool bed for machine tools are high structural stiffness and high damping, which cannot be satisfied simultaneously if conventional metallic materials such as cast iron are employed. Hence there is a need to replace cast iron with alternate materials. Approach: The objective of this study is to improve t...

  9. New active machine tool drive mounting on the frame

    Directory of Open Access Journals (Sweden)

    Švéda J.

    2007-10-01

    Full Text Available The paper deals with the new active mounting of the machine tool drives. The commonly used machine tools are at this time mainly equipped with fix-mounting of the feed drives. This structure causes full transmission of the force shocks to the machine bed and thereby restricts the dynamic properties of the motion axis and the whole machine. The spring-mounting of the feed drives is one of the possibilities how to partially suppress the vibrations. The force that reacts to the machine tool bed is transformed thereby the vibrations are lightly reduced. Unfortunately the transformation is not fully controlled. The new active mounting of the machine tool drives allows to fully control the force behaviour that react to the machine body. Thereby the number of excited frequencies on the machine tool bed is significantly reduced. The active variant of the feed drive mounting is characterized by the synergistic cooperation between two series-connected actuators (“motor on motor”. The paper briefly describes design, control techniques and optimization of the feed drives with the new active mounting conception.

  10. ATST telescope mount: telescope of machine tool

    Science.gov (United States)

    Jeffers, Paul; Stolz, Günter; Bonomi, Giovanni; Dreyer, Oliver; Kärcher, Hans

    2012-09-01

    The Advanced Technology Solar Telescope (ATST) will be the largest solar telescope in the world, and will be able to provide the sharpest views ever taken of the solar surface. The telescope has a 4m aperture primary mirror, however due to the off axis nature of the optical layout, the telescope mount has proportions similar to an 8 meter class telescope. The technology normally used in this class of telescope is well understood in the telescope community and has been successfully implemented in numerous projects. The world of large machine tools has developed in a separate realm with similar levels of performance requirement but different boundary conditions. In addition the competitive nature of private industry has encouraged development and usage of more cost effective solutions both in initial capital cost and thru-life operating cost. Telescope mounts move relatively slowly with requirements for high stability under external environmental influences such as wind buffeting. Large machine tools operate under high speed requirements coupled with high application of force through the machine but with little or no external environmental influences. The benefits of these parallel development paths and the ATST system requirements are being combined in the ATST Telescope Mount Assembly (TMA). The process of balancing the system requirements with new technologies is based on the experience of the ATST project team, Ingersoll Machine Tools who are the main contractor for the TMA and MT Mechatronics who are their design subcontractors. This paper highlights a number of these proven technologies from the commercially driven machine tool world that are being introduced to the TMA design. Also the challenges of integrating and ensuring that the differences in application requirements are accounted for in the design are discussed.

  11. 基于结合面的机床动态特性研究%Research on Dynamics Characteristics of Machine Tool Based on Joints

    Institute of Scientific and Technical Information of China (English)

    罗卫平; 王珺

    2011-01-01

    A virtual prototype model of machine tool is constructed by using the Pro/E software and the ANSYS software. Considering the effects of joints,this paper makes a study of dynamic analyses of machine tool and the effect of joints on the dynamic characteristics of machine tool to attain the purpose of synthetically predicting and evaluating the NC machine tool dynamic performance without a physical sample.%运用三维建模软件Pro/E和有限元分析软件ANSYS,建立了虚拟样机模型.考虑结合面的影响,对机床进行了动态分析,研究结合面对于机械结构动态特性的影响,实现无物理样机环境下机床整体动力学性能预测和综合评价的目的.

  12. Setting of angles on machine tools speeded by magnetic protractor

    Science.gov (United States)

    Vale, L. B.

    1964-01-01

    An adjustable protractor facilitates transference of angles to remote machine tools. It has a magnetic base incorporating a beam which can be adjusted until its shadow coincides with an image on the screen of a projector.

  13. [Research on infrared safety protection system for machine tool].

    Science.gov (United States)

    Zhang, Shuan-Ji; Zhang, Zhi-Ling; Yan, Hui-Ying; Wang, Song-De

    2008-04-01

    In order to ensure personal safety and prevent injury accident in machine tool operation, an infrared machine tool safety system was designed with infrared transmitting-receiving module, memory self-locked relay and voice recording-playing module. When the operator does not enter the danger area, the system has no response. Once the operator's whole or part of body enters the danger area and shades the infrared beam, the system will alarm and output an control signal to the machine tool executive element, and at the same time, the system makes the machine tool emergency stop to prevent equipment damaged and person injured. The system has a module framework, and has many advantages including safety, reliability, common use, circuit simplicity, maintenance convenience, low power consumption, low costs, working stability, easy debugging, vibration resistance and interference resistance. It is suitable for being installed and used in different machine tools such as punch machine, pour plastic machine, digital control machine, armor plate cutting machine, pipe bending machine, oil pressure machine etc.

  14. Research on Visual Virtual Design Platform for NC Machine Tools

    Institute of Scientific and Technical Information of China (English)

    HU Rufu; CHEN Xiaoping; SUN Qinghong

    2006-01-01

    The fundamental ideas on building the collaborative design platform of virtual visualization for NC machine tools are introduced. The platform is based on the globally shared product model conforming to the STEP Standard, and used PDM system to integrate and encapsulate CAD/CAE and other application software for the product development. The platform also integrated the expert system of NC machine tools design, analysis and estimation. This expert system utilized fuzzy estimation principle to evaluate the design and simulation analysis results and make decisions. The platform provides the collaborative intelligent environment for the design of virtual NC machine tools prototype aiming at integrated product design team. It also supports the customized development of NC machine tools.

  15. 基于刚柔耦合的数控机床动态特性分析%Analysis of Dynamic Characteristics of NC Machine Tools Based on Rigid-flexible Coupling

    Institute of Scientific and Technical Information of China (English)

    罗卫平

    2011-01-01

    Based on the developed virtual sample model of five-axis numerical control gantry machine tool, the main component——the crossbeam was set to flexible, and a flexible-rigid coupling multi-system dynamic prototype of the whole machine was established. The influence on operational stability of the machine tool by the flexible effect of the crossbeam was analyzed. The results show that simulation analysis based on a rigid-flexible coupling model is more accurate to show dynamics characteristics of machine tools. It provides theoretical basis for structure optimal design of the machine tool.%在所开发的五坐标龙门数控机床虚拟样机的基础上,对其关键部位--横梁进行柔性化,建立了整机的刚柔耦合多体动力学模型,分析讨论横梁的柔性效应对机床运行稳定性的影响.结果表明:基于刚柔耦合模型的仿真分析更为准确地反映了机床的动力学特征,为最终实现机床结构优化设计提供可靠的理论依据.

  16. Design of equipment for training machine tools

    Directory of Open Access Journals (Sweden)

    Císar Miroslav

    2017-01-01

    Full Text Available The article proposes multiple devices designed to be used with training machine tools EMCO Concept series. Design was focused to enchant educational potential of training machine tools located in the laboratory of CNC programing, department of automation and production systems, Faculty of mechanical engineering, University of Zilina. The described device allows monitoring of machine tool, to measure tool offset and dimension, to use alternative ways of clamping, and to create video of machining.

  17. Calibration of a Parallel Kinematic Machine Tool

    Institute of Scientific and Technical Information of China (English)

    HE Xiao-mei; DING Hong-sheng; FU Tie; XIE Dian-huang; XU Jin-zhong; LI Hua-feng; LIU Hui-lin

    2006-01-01

    A calibration method is presented to enhance the static accuracy of a parallel kinematic machine tool by using a coordinate measuring machine and a laser tracker. According to the established calibration model and the calibration experiment, the factual 42 kinematic parameters of BKX-I parallel kinematic machine tool are obtained. By circular tests the comparison is made between the calibrated and the uncalibrated parameters and shows that there is 80% improvement in accuracy of this machine tool.

  18. Machine Tool Advanced Skills Technology (MAST). Common Ground: Toward a Standards-Based Training System for the U.S. Machine Tool and Metal Related Industries. Volume 7: Industrial Maintenance Technology, of a 15-Volume Set of Skill Standards and Curriculum Training Materials for the Precision Manufacturing Industry.

    Science.gov (United States)

    Texas State Technical Coll., Waco.

    This document is intended to help education and training institutions deliver the Machine Tool Advanced Skills Technology (MAST) curriculum to a variety of individuals and organizations. MAST consists of industry-specific skill standards and model curricula for 15 occupational specialty areas within the U.S. machine tool and metals-related…

  19. Machine Tool Advanced Skills Technology (MAST). Common Ground: Toward a Standards-Based Training System for the U.S. Machine Tool and Metal Related Industries. Volume 11: Computer-Aided Manufacturing & Advanced CNC, of a 15-Volume Set of Skill Standards and Curriculum Training Materials for the Precision Manufacturing Industry.

    Science.gov (United States)

    Texas State Technical Coll., Waco.

    This document is intended to help education and training institutions deliver the Machine Tool Advanced Skills Technology (MAST) curriculum to a variety of individuals and organizations. MAST consists of industry-specific skill standards and model curricula for 15 occupational specialty areas within the U.S. machine tool and metals-related…

  20. Machine Tool Advanced Skills Technology (MAST). Common Ground: Toward a Standards-Based Training System for the U.S. Machine Tool and Metal Related Industries. Volume 13: Laser Machining, of a 15-Volume Set of Skill Standards and Curriculum Training Materials for the Precision Manufacturing Industry.

    Science.gov (United States)

    Texas State Technical Coll., Waco.

    This document is intended to help education and training institutions deliver the Machine Tool Advanced Skills Technology (MAST) curriculum to a variety of individuals and organizations. MAST consists of industry-specific skill standards and model curricula for 15 occupational specialty areas within the U.S. machine tool and metals-related…

  1. Machine Tool Advanced Skills Technology (MAST). Common Ground: Toward a Standards-Based Training System for the U.S. Machine Tool and Metal Related Industries. Volume 14: Automated Equipment Technician (CIM), of a 15-Volume Set of Skill Standards and Curriculum Training Materials for the Precision Manufacturing Industry.

    Science.gov (United States)

    Texas State Technical Coll., Waco.

    This document is intended to help education and training institutions deliver the Machine Tool Advanced Skills Technology (MAST) curriculum to a variety of individuals and organizations. MAST consists of industry-specific skill standards and model curricula for 15 occupational specialty areas within the U.S. machine tool and metals-related…

  2. Machine Tool Advanced Skills Technology (MAST). Common Ground: Toward a Standards-Based Training System for the U.S. Machine Tool and Metal Related Industries. Volume 1: Executive Summary, of a 15-Volume Set of Skills Standards and Curriculum Training Materials for the Precision Manufacturing Industry.

    Science.gov (United States)

    Texas State Technical Coll., Waco.

    The Machine Tool Advanced Skills Technology (MAST) consortium was formed to address the shortage of skilled workers for the machine tools and metals-related industries. Featuring six of the nation's leading advanced technology centers, the MAST consortium developed, tested, and disseminated industry-specific skill standards and model curricula for…

  3. 退役机床再制造整机性能综合提升方案%Design of machine-based comprehensive upgrading scheme for machine tool remanufacturing

    Institute of Scientific and Technical Information of China (English)

    杜彦斌; 李智明

    2014-01-01

    At present ,there are lots of used machine tools in China which need to be remanufactured to restore and enhance their performance as well as meet the ever-increasing processing requirements at a low cost .Compared with existing maintenance or NC transformation of machine tools ,machine tool remanufacturing can not only restore used ones to normal operation ,but also upgrade machine performance and endow a new life cycle to used machine tools .The machine-based comprehensive upgrading scheme for machine tool remanufacturing is presented from the aspects of energy-saving,environmental friendliness and information function . The technical path and technical solutions are proposed .In addition ,the implementation effects of machine tool upgrading are il-lustrated with the case of lathe and gear hobbing machine remanufacturing .%目前,我国存在大量的退役机床迫切需要实施再制造来恢复并提升其性能水平,以便低成本、绿色化地满足不断提高的零/部件加工要求。机床再制造与已有的维修、数控化改造相比,最重要的区别是其不仅仅恢复退役机床的性能使其正常运转,还要实现机床整机性能的综合提升,重新赋予退役机床新的生命周期。从节能性、环境友好性和信息化等方面,对退役机床再制造整机性能提升方案进行分析,阐述相关的技术路径与技术方案;以车床、滚齿机再制造为例,对相关方案实施效果进行分析。

  4. Research on machine tool design and simulation based on virtual prototype%基于虚拟样机的机床设计与仿真研究

    Institute of Scientific and Technical Information of China (English)

    高清冉; 孙海燕; 李海洪; 周晓亮

    2009-01-01

    为了提高机床的设计水平,将虚拟样机技术引入机床的设计开发过程,通过虚拟样机技术的使用辅助设计人员进行方案分析.利用三维造型软件SolidWorks实现虚拟样机模型的建立,应用对象的链接与嵌套技术进行数控加工仿真、刀具轨迹显示、自动换刀和毛坯的自动设计,采用仿真软件ADAMS实现了该机床的动力学分析和仿真.将上述方法应用于并联机床的具体设计中,计算机仿真结果验证了理论模型的合理性,进而验证了设计的正确性和可靠性.%For the sake of enhancing the designing level of ma-chine tools, the virtual prototype technology was introduced into the designing development process of machine tools. By means of em- ploying virtual prototype technology the designers was assisted in carrying out the scheme analysis. Utilizating the 3D modelling soft-ware SolidWorks, the establishment of virtual prototype model was realized. By applying the linkage of object and inlaid technology to carrying out numerical controlled machining simulation, display of cutter track, automatic tool change and automatic design of blank. The dynamics analysis and simulation of this machine tool were car-ried out by adopting the simulation software ADAMS. Let the above stated method be applied to a concrete design of parallel machine tools, the result of computer simulation verified the rationality of theoretical model and then testified the correctness and reliability of the design.

  5. Optimal Machine Tools Selection Using Interval-Valued Data FCM Clustering Algorithm

    Directory of Open Access Journals (Sweden)

    Yupeng Xin

    2014-01-01

    Full Text Available Machine tool selection directly affects production rates, accuracy, and flexibility. In order to quickly and accurately select the appropriate machine tools in machining process planning, this paper proposes an optimal machine tools selection method based on interval-valued data fuzzy C-means (FCM clustering algorithm. We define the machining capability meta (MAE as the smallest unit to describe machining capacity of machine tools and establish MAE library based on the MAE information model. According to the manufacturing process requirements, the MAEs can be queried from MAE library. Subsequently, interval-valued data FCM algorithm is used to select the appropriate machine tools for manufacturing process. Through computing matching degree between manufacturing process machining constraints and MAEs, we get the most appropriate MAEs and the corresponding machine tools. Finally, a case study of an exhaust duct part of the aeroengine is presented to demonstrate the applicability of the proposed method.

  6. 基于熵权与层次分析法的机床再制造方案综合评价%Evaluation of machine tool remanufacturing scheme based on entropy weight and AHP

    Institute of Scientific and Technical Information of China (English)

    杜彦斌; 曹华军; 刘飞; 鄢萍; 李聪波

    2011-01-01

    结合机床再制造实践,建立了包括经济性、技术性、资源性、环境性的机床再制造方案综合评价指标体系,并对各个指标的量化方法进行了分析;提出了一种基于熵权与层次分析法的机床再制造方案综合评价方法.通过在某企业车床再制造中的应用,验证了所提方法的有效性.%According to the practice of machine tool remanufacturing, the evaluation index system of machine tool re manufacturing which included economy, technology, resource and environment was established, and the quantitative methods of the indexes were analyzed.In addition, the evaluation method of machine tool remanufacturing scheme based on entropy weight and Analytic Hierarchy Process (AHP) was proposed.Finally, this method was applied in an enterprise's lathe remanufacturing, and its effectiveness was verified.

  7. Accuracy Analysis and Calibration of Gantry Hybrid Machine Tool

    Institute of Scientific and Technical Information of China (English)

    唐晓强; 李铁民; 尹文生; 汪劲松

    2003-01-01

    The kinematic accuracy is a key factor in the design of parallel or hybrid machine tools. This analysis improved the accuracy of a 4-DOF (degree of freedom) gantry hybrid machine tool based on a 3-DOF planar parallel manipulator by compensating for various positioning errors. The machine tool architecture was described with the inverse kinematic solution. The control parameter error model was used to analyze the accuracy of the 3-DOF planar parallel manipulator and to develop a kinematic calibration method. The experimental results prove that the calibration method reduces the cutter nose errors from ±0.50 mm to ±0.03 mm for a horizontal movement of 600 mm by compensating for errors in the slider home position, the guide way distance and the extensible strut home position. The calibration method will be useful for similar types of parallel kinematic machines.

  8. Case study of virtual reality in CNC machine tool exhibition

    Directory of Open Access Journals (Sweden)

    Kao Yung-Chou

    2017-01-01

    Full Text Available Exhibition and demonstration are generally used in the promotion and sale-assistance of manufactured products. However, the transportation cost of the real goods from the vender factory to the exposition venue is generally expensive for huge and heavy commodity. With the advancement of computing, graphics, mobile apps, and mobile hardware the 3D visibility technology is getting more and more popular to be adopted in visual-assisted communication such as amusement games. Virtual reality (VR technology has therefore being paid great attention in emulating expensive small and/or huge and heavy equipment. Virtual reality can be characterized as 3D extension with Immersion, Interaction and Imagination. This paper was then be focused on the study of virtual reality in the assistance of CNC machine tool demonstration and exhibition. A commercial CNC machine tool was used in this study to illustrate the effectiveness and usability of using virtual reality for an exhibition. The adopted CNC machine tool is a large and heavy mill-turn machine with the width up to eleven meters and weighted about 35 tons. A head-mounted display (HMD was attached to the developed VR CNC machine tool for the immersion viewing. A user can see around the 3D scene of the large mill-turn machine and the operation of the virtual CNC machine can be actuated by bare hand. Coolant was added to demonstrate more realistic operation while collision detection function was also added to remind the operator. The developed VR demonstration system has been presented in the 2017 Taipei International Machine Tool Show (TIMTOS 2017. This case study has shown that young engineers and/or students are very impressed by the VR-based demonstration while elder persons could not adapt themselves easily to the VR-based scene because of eyesight issues. However, virtual reality has successfully being adopted and integrated with the CNC machine tool in an international show. Another machine tool on

  9. Cast Iron And Mineral Cast Applied For Machine Tool Bed - Dynamic Behavior Analysis

    OpenAIRE

    2015-01-01

    Cast iron and mineral cast are the materials most often used in the machine structural elements design (bodies, housings, machine tools beds etc.). The materials significantly differ in physical and mechanical properties. The ability to suppress vibration is one of the most important factors determining the dynamic properties of the machine and has a significant impact on the machining capabilities of a machine tool. Recent research and development trends show that there is a clear tendency t...

  10. Transition Towards Energy Efficient Machine Tools

    CERN Document Server

    Zein, André

    2012-01-01

    Energy efficiency represents a cost-effective and immediate strategy of a sustainable development. Due to substantial environmental and economic implications, a strong emphasis is put on the electrical energy requirements of machine tools for metalworking processes. The improvement of energy efficiency is however confronted with diverse barriers, which sustain an energy efficiency gap of unexploited potential. The deficiencies lie in the lack of information about the actual energy requirements of machine tools, a minimum energy reference to quantify improvement potential and the possible actions to improve the energy demand. Therefore, a comprehensive concept for energy performance management of machine tools is developed which guides the transition towards energy efficient machine tools. It is structured in four innovative concept modules, which are embedded into step-by-step workflow models. The capability of the performance management concept is demonstrated in an automotive manufacturing environment. The ...

  11. How To Teach Common Characteristics of Machine Tools

    Science.gov (United States)

    Kazanas, H. C.

    1970-01-01

    Organizes machine tools and machine operations into commonalities in order to help the student visualize and distinguish the common characteristics which exist between machine tools and operations. (GR)

  12. Design and Analysis of CNC Machine Tool Based on Ergonomics%基于人机工程学的数控机床设计与分析

    Institute of Scientific and Technical Information of China (English)

    刘涛; 陈明

    2014-01-01

    It has outlined the method of humanized design of CNC machine tool,, and has put forward their owner design points from the each appearance units of the CNC lathe—left fixed cover, right fixed cover, door, window and handle. In order to better illustrate the ergonomical design point of the each unit parts, Through an successful example , it has discussed how to use the ergonomical design points in the each ap-pearance unit of the CNC lathe . The contents of the design and analysis have a certain reference value for the personnel who are studying the appearance design of CNC machine tool.%针对数控机床人性化设计方法进行概述,并分别从数控车床外观造型中各个单元部件—左固定罩、右固定罩、拉门、观察窗与拉手,提出了其各自的人机工程学设计要点。为了能够更好的说明个单元部件的人机工程学设计要点,通过一成功的设计实例论述了在设计中如何运用数控车床单元部件的人机工程学设计要点。其设计与分析内容对于从事数控机床外观造型设计的工作人员具有一定的参考价值。

  13. Application of Maintenance Simulate System of NC Machine Tools in Teaching

    Directory of Open Access Journals (Sweden)

    He Xin

    2017-01-01

    Full Text Available The project design is the foundation of training, which can insure the usefulness of human resource development system. The Training Project Maintenance Simulate System of NC Machine Tools is presented based on analyzed contradiction between supply and demand. This paper introduces several scheme of Maintenance Simulate System of NC Machine Tools.

  14. Design of Five-Axis Ultrasonic Assistant Compound Machine Tool

    Institute of Scientific and Technical Information of China (English)

    Liu Bing刘冰; Fang Fengzhou房丰洲; Xu Zongwei徐宗伟; Zhang Xiaofeng张晓峰

    2015-01-01

    A compound machine tool was designed, which combined rotary ultrasonic assisted grinding, electrical discharge machining (EDM) and multi-axis milling. Experimental results indicated that its positioning accuracy was less than 5.6μm and its repetitive positioning accuracy was less than 1.8μm;the vibration amplitude of ultrasonic grinding system was uniform and stable, and the EDM system worked well and stably.A smooth surface of K9 optical glass component was achieved by the grinding method.

  15. Chip breaking system for automated machine tool

    Science.gov (United States)

    Arehart, Theodore A.; Carey, Donald O.

    1987-01-01

    The invention is a rotary selectively directional valve assembly for use in an automated turret lathe for directing a stream of high pressure liquid machining coolant to the interface of a machine tool and workpiece for breaking up ribbon-shaped chips during the formation thereof so as to inhibit scratching or other marring of the machined surfaces by these ribbon-shaped chips. The valve assembly is provided by a manifold arrangement having a plurality of circumferentially spaced apart ports each coupled to a machine tool. The manifold is rotatable with the turret when the turret is positioned for alignment of a machine tool in a machining relationship with the workpiece. The manifold is connected to a non-rotational header having a single passageway therethrough which conveys the high pressure coolant to only the port in the manifold which is in registry with the tool disposed in a working relationship with the workpiece. To position the machine tools the turret is rotated and one of the tools is placed in a material-removing relationship of the workpiece. The passageway in the header and one of the ports in the manifold arrangement are then automatically aligned to supply the machining coolant to the machine tool workpiece interface for breaking up of the chips as well as cooling the tool and workpiece during the machining operation.

  16. Analysis and testing research on dynamic properties of machine tools based on joints parameters%基于结合面参数的整机动态特性分析与试验研究

    Institute of Scientific and Technical Information of China (English)

    郭成龙; 袁军堂; 李奎; 翁德凯; 陈展翼

    2012-01-01

    Since the joint surface properties of the machine tools influences the performance of the machine tools greatly,modal analysis of vertical milling machine tool AVCP1200H was carried out utilizing ANSYS based on the finite element models of rigid connection and flexible connection of the joints.Then the analyzing tests for two finite element models were verified to be identical through modal test to the machine.In addition the reasons of test error occurred were analyzed and optimization for the model was sug-gested, which provided a reference for studying dynamics of the machine tools as well as digital design and manufacturing.The test results show that: the modal analysis for flexible connection of the joints was in good agreement with the hammering test results with 3 order more errors being within 20%,which dynamic characteristic parameters were proven to impact the performance of the machine significantly.%机床结合面特性对其整体性能具有很大影响,利用ANSYS软件分别对立式数控铣床AVCP1200H结合面刚性联接、柔性联接的有限元模型进行模态分析,然后通过整机模态试验验证两种有限元模型的分析吻合,并对试验误差产生的原因进行分析,提出了优化模型的建议,为该型机床动力学研究及数字化设计制造提供了参考.试验结果表明:结合面柔性联接的模态分析与锤击试验结果较为吻合,3阶以上的误差均在20%以内,证明结合面处的动态特性参数对机床性能有很大影响.

  17. 3-PRS serial-parallel machine tool error calibration and parameter identification

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jun-wei; DAI Jun; HUANG Jun-jie

    2009-01-01

    3-PRS serial-parallel machine tool consists of a 3-degree-of-freedom (DOF) implementation platform and a 2-DOF X-Y platform. The error modeling and parameter identification methods were deduced based on 3-PRS serial-parallel machine tool. 3-PRS serial-parallel machine tool was researched, and the mechanism of error analysis, modeling, identification of error parameters and measurement equipment for the use of agency error of measurement were conducted. In order to achieve the geometric parameters calibration and error compensation of the serial-parallel machine tool, the nominal structural parameters of the controller was adjusted by identifying the structure of the machine tool. With the establishment of a vector space size chain, we can do the error analysis, error modeling, error measurement and error compensation can be done.

  18. 基于FEM的数控弧齿铣齿机立柱结构静、动态设计%FEM-Based Static & Dynamic Design of Computer Numerical Control Bevel Gear Machine Tool Column

    Institute of Scientific and Technical Information of China (English)

    李翼龙; 郭志全; 刘明涛; 李彦启

    2012-01-01

    借助有限元分析软件,运用结构动态设计原理和基于有限元法的变量化分析技术对数控弧齿铣齿机立柱部件进行动、静态特性分析,并以立柱结构的侧板宽度为几何参数进行灵敏度分析,找出原设计中的不足,并在结构及尺寸上加以改进.结果表明,改进后立柱的动、静态性能得到显著的提高,为机床设计和改造提供了依据.%By using finite element analysis software, structural dynamic design principle,and variational analysis technique based on finite element method (FEM), a static and dynamic characteristic analysis was carried out on the column structure of numerical control bevel gear machine tool. Sensitivity analysis was also conducted according to the geometric parameters of the column structure. The deficiencies in the original design were found out and then improved in both the structure and measure. The results show that the static and dynamic performance of the improved column has been increased significantly, so this method can offer bases for the design and renovation of machine tools.

  19. Machine-Tool Technology Instructor's Sourcebook.

    Science.gov (United States)

    Tammer, Anthony M.

    This document lists and annotates commercial and noncommercial resources pertaining to machine-tool technology. Following an introduction that explains how the document came to be written, the subjects of succeeding chapters are (1) periodicals; (2) associations; (3) audiovisual resources, including a subject index; (4) publishers, including a…

  20. Numerically Controlled Machine Tools and Worker Skills.

    Science.gov (United States)

    Keefe, Jeffrey H.

    1991-01-01

    Analysis of data from "Industry Wage Surveys of Machinery Manufacturers" on the skill levels of 57 machining jobs found that introduction of numerically controlled machine tools has resulted in a very small reduction in skill levels or no significant change, supporting neither the deskilling argument nor argument that skill levels…

  1. Numerically Controlled Machine Tools and Worker Skills.

    Science.gov (United States)

    Keefe, Jeffrey H.

    1991-01-01

    Analysis of data from "Industry Wage Surveys of Machinery Manufacturers" on the skill levels of 57 machining jobs found that introduction of numerically controlled machine tools has resulted in a very small reduction in skill levels or no significant change, supporting neither the deskilling argument nor argument that skill levels…

  2. Technology network for machine tools in Vietnam

    OpenAIRE

    Mizuno, Junko

    2012-01-01

    When Vietnam joined the WTO, it accepted foreign direct investment and started to grow. Technically, it was then greatly influenced by the enterprises that entered the country through direct investment. This report shows that the technology network for machine tools is formed via direct investment and subcontracting.

  3. 基于AVR的数控机床椭圆插补的研究%Research on ellipse interpolation program for numerical control machine tool based on AVR

    Institute of Scientific and Technical Information of China (English)

    王晋

    2012-01-01

    插补模块是数控系统的核心.随着现代数控技术的不断发展,插补算法不断成熟,类型众多.对于开放型机床数控系统的设计来说,目前重点的工作是如何选择合适的硬件系统实现实时插补.从而使得控制系统更稳定、插补运算更可靠、速度更快.主要介绍了在AT-MEGA16单片机控制系统中实现椭圆插补,并且推导出了椭圆插补的偏差公式,并且给出了程序框图.最后利用ATMEGA16单片机对算法进行了编程实现.%Interpolation module is the core of the numerieal control system. Along with the development of the modern numerical control technology, the interpolation algorithm is maturing and diversifying step by step. As for the design of open numerical control machine tool system, the priority job at present is how to choose a proper hardware system to interpolation. So that the control system becomes more stable, and the interpolation algorithm would become more reliable and quicker. This paper describes a control system in the ATMEGA16 microcontroller to achieve elliptical interpolation , and derive a formula for elliptic interpolation error,and gives die block diagram.

  4. A Method for Design of Modular Reconfigurable Machine Tools

    Directory of Open Access Journals (Sweden)

    Zhengyi Xu

    2017-02-01

    Full Text Available Presented in this paper is a method for the design of modular reconfigurable machine tools (MRMTs. An MRMT is capable of using a minimal number of modules through reconfiguration to perform the required machining tasks for a family of parts. The proposed method consists of three steps: module identification, module determination, and layout synthesis. In the first step, the module components are collected from a family of general-purpose machines to establish a module library. In the second step, for a given family of parts to be machined, a set of needed modules are selected from the module library to construct a desired reconfigurable machine tool. In the third step, a final machine layout is decided though evaluation by considering a number of performance indices. Based on this method, a software package has been developed that can design an MRMT for a given part family.

  5. INVERSE DYNAMIC FORMULATION OF A NOVEL HYBRID MACHINE TOOL

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In recent years, hybrid devices have increasingly received more research.However, few of researchers studied the dynamic analysis.The inverse dynamic analysis of a novel hybrid machine tool designed in Tsinghua University is presented.The hybrid machine tool under consideration consists of parallel and serial structures, which is based on a new 2-DOF parallel platform and serial orientations.The kinematics and the dynamic equations are studied first for the parallel structure through Newton-Euler approach.And then, the dynamic analysis for serial structures is conducted.Finally, a closed-form inverse dynamic formulation is derived by using some elimination techniques.Some simulation results are also given.

  6. 基于最大熵原理与鉴别信息的机床主轴系统退化分析%Degradation analysis of machine tool spindle based on maximum entropy and discrimination information

    Institute of Scientific and Technical Information of China (English)

    董新峰; 李郝林; 余慧杰

    2013-01-01

    The methods of maximum entropy and discrimination information were applied to the analysis of X2 direction degradation of a M1432 grinding machine. The maximum entropy principle was used to obtain the accurate maximum entropy probability density distribution of the vibration. Then, the discrimination information was made in use to analyze the variations of maximum entropy probability density distribution that can judge the state of machine tool spindle system. The results show that in the X2 direction, the workpiece spindle in the example has tiny degradation.%采用最大熵原理与鉴别信息方法对M1432B型磨床工件主轴X2方向退化进行分析:用最大熵原理获得工件主轴在4 ~10月份振动信号最大熵概率密度分布,再用鉴别信息对该概率密度分布变化进行计算,通过鉴别信息变化判断主轴系统状态的变化,结果表明,M1432B型磨床工件主轴x2方向发生微小退化.

  7. Research on Positioning Error Compensation for Micro Milling Machine Tool

    Institute of Scientific and Technical Information of China (English)

    Ming-Jun Chen; Wen-Lan Tian; Yong Xiao; Yan Jiang

    2014-01-01

    Micro milling has many advantages in fabricating three⁃dimensional ( 3D) structure in micrometer scale. The micro milling machine tool with high positioning accuracy is of great importance for getting micro structure with high profile precision and good surface quality. Meanwhile, the method of position error compensation is a good way to improve the accuracy of the micro milling machine tools. In this paper, a software method is adopted to compensate the positioning error and improve the positioning accuracy. According to error cancellation theory, the compensation values are generated and compensation tables are built to adjust the positioning error in the NC system based on Industrial Motion and Automation Control ( IMAC) . The positioning accuracy of linear motor is ±0�3μm without backlash after compensation. In order to verify the effectiveness of compensation on the machining performance, concave spherical surfaces are processed on the micro milling machine tool. The experimental results show that the profile radius error of the spherical surface machined with compensation decreases more than 60%.

  8. Machine tool metrology an industrial handbook

    CERN Document Server

    Smith, Graham T

    2016-01-01

    Maximizing reader insights into the key scientific disciplines of Machine Tool Metrology, this text will prove useful for the industrial-practitioner and those interested in the operation of machine tools. Within this current level of industrial-content, this book incorporates significant usage of the existing published literature and valid information obtained from a wide-spectrum of manufacturers of plant, equipment and instrumentation before putting forward novel ideas and methodologies. Providing easy to understand bullet points and lucid descriptions of metrological and calibration subjects, this book aids reader understanding of the topics discussed whilst adding a voluminous-amount of footnotes utilised throughout all of the chapters, which adds some additional detail to the subject. Featuring an extensive amount of photographic-support, this book will serve as a key reference text for all those involved in the field. .

  9. 基于ADAMS的PRS- XY型混联机床机构运动学仿真分析%Kinematics Analysis and Simulation of the PRS- XY Hybrid Mechanism of the Machine Tool Based on ADAMS

    Institute of Scientific and Technical Information of China (English)

    朱海宁; 郭钢; 李传龙

    2011-01-01

    应用ADAMS软件对PRS - XY型混联机床机构进行运动学仿真分析,使用测量工具求得混联机构逆解,然后通过样条曲线和样条函数求得正解.借助于仿真软件快速准确地求出运动学正逆解,为实际的样机调试提供了有意义的借鉴.%Based on ADAMS, it simulates and analyzes the kinematics performance of the PRS- XY hybrid mechanism of the machine tool. It solves the kinematics functions of the PRS- XY mechanism with measuring tools and spline function, and proves that this solution model and the inverse solution model of kinematics of the hybrid mechanism are effective and rapid.

  10. Parametric programming of CNC machine tools

    Directory of Open Access Journals (Sweden)

    Gołębski Rafał

    2017-01-01

    Full Text Available The article presents the possibilities of parametric programming of CNC machine tools for the SINUMERIK 840D sl control system. The kinds and types of the definition of variables for the control system under discussion described. On the example of the longitudinal cutting cycle, parametric programming possibilities are shown. The program’s code and its implementation in the control system is described in detail. The principle of parametric programming in a high-level language is also explained.

  11. Automatic Calibration Of Manual Machine Tools

    Science.gov (United States)

    Gurney, Rex D.

    1990-01-01

    Modified scheme uses data from multiple positions and eliminates tedious positioning. Modification of computer program adapts calibration system for convenient use with manually-controlled machine tools. Developed for use on computer-controlled tools. Option added to calibration program allows data on random tool-axis positions to be entered manually into computer for reduction. Instead of setting axis to predetermined positions, operator merely sets it at variety of arbitrary positions.

  12. Speed-Selector Guard For Machine Tool

    Science.gov (United States)

    Shakhshir, Roda J.; Valentine, Richard L.

    1992-01-01

    Simple guardplate prevents accidental reversal of direction of rotation or sudden change of speed of lathe, milling machine, or other machine tool. Custom-made for specific machine and control settings. Allows control lever to be placed at only one setting. Operator uses handle to slide guard to engage or disengage control lever. Protects personnel from injury and equipment from damage occurring if speed- or direction-control lever inadvertently placed in wrong position.

  13. USSR Report Machine Tools and Metalworking Equipment

    Science.gov (United States)

    2007-11-02

    determined, therefore, by the shape of the machined surface and is spatial , i.e., kinematically the most complicated one, different for each machined...place in a single hour. But in actuality? Perhaps it began when they began to study the loading of the production capacities of the sections... kindergartens , the machine tools are outdated and there is nowhere to rest." "At that time I said to myself: ’First achieve their confidence; this

  14. 基于Access数据库的机床滑台选型系统开发与实践%Practice and development of machine tool slide-unit selection system based on Access

    Institute of Scientific and Technical Information of China (English)

    肖霞; 石铁铮; 修世超

    2013-01-01

    Aiming at solving the problems of an inefficient and mistakable method to select slide-unit types for machine tool design in machine tool manufacturers by searching and reusing the relevant technique information from universal slide unit specifications and their bills of materials manually,the machine tool slide-unit selection system based on Microsoft Access was investigated. After the analysis of the slide unit type selection task and the hardware and software condition as well as the information management level of the company,the relationships between "designing requirements for slide-unit" and "universal slide-unit specifications", and those between "slide-units' bills of materials", were established. A method was presented to select the slide-unit type by means of the Access database. The slide-unit type selection model was evaluated on the efficiency and accuracy. The type selection system for more than 100 slide-units concerning several projects was tested. The experimental results indicate that this system can record the slide unit production history, automatically create "advice for starting production", "wearing parts of slide unit" and other design or production documents and other statistical reports, which reduces intensity of labor and artificial errors and improves working efficiency. It also indicates that this system can help the company to build a knowledge base for later reference and provide a reliable data base for the machine tool digital design.%机床制造企业在设计过程中常采用手工方式查找和抄录通用滑台规格表中的相关信息以选择通用滑台型号的方法,针对其所带来的效率低下、容易出错等问题,将Microsoft Access数据库技术应用到企业机床设计的通用滑台选型过程中,开展了机床制造企业通用滑台规格选型的任务需求分析和企业当前计算机网络软硬件条件与信息化管理水平分析,建立了企业滑台设计任务书与通用滑台规格

  15. Enterprise brand construction based on the enterprise in bowang machine tool industry cluster%基于企业视角的博望机床产业品牌建设

    Institute of Scientific and Technical Information of China (English)

    何莉; 吴永纯; 李德俊

    2011-01-01

    Bowang town is an under developed typical region.The present situation of Bowang machine tool industry cluster is investigated.Based on the brand,the problems in the development are analyzed,like brand awareness,weak brand foundation,few number of brands,low brand quality,the cluster consciousness indifference.The countermeasures for the Bowang machine tool industry cluster are explored:strengthening brand awareness,reinforceing brand and striving for brand management,enhancing brand innovation,expanding and growing stronger brand relying on industry clusters.%博望镇是欠发达地区产业集群的典型区域,深入到博望镇及博望机床企业了解其产业和品牌建设现状.基于企业的视角,剖析博望机床产业品牌存在的问题:品牌意识不强、品牌基础薄弱、品牌数量偏少、品牌品质偏低、集群意识淡漠.探讨适合于博望机床产业品牌发展的对策:加强品牌意识、夯实品牌基础、提升品牌管理力度、加强品牌创新、依托产业集群做大做强企业品牌.

  16. An Identification Approach for Key Geometric Error Sources of Machine Tool Based on Sensitivity Analysis%基于敏感度分析的机床关键性几何误差源识别方法

    Institute of Scientific and Technical Information of China (English)

    程强; 刘广博; 刘志峰; 玄东升; 常文芬

    2012-01-01

    The volumetric error coupled by geometric errors of parts is the main reason affecting the machining accuracy. How to determine the influence degree on the processing precision generated by the geometric errors of parts, thus distribute the geometric errors of parts economically and reasonably, is currently a difficult problem of machine tool design. Based on the theory of multi-body system and sensitivity analysis, a new method of identifying the key geometric error sources parameters is proposed. Taking a four-axis precision horizontal machining center as example, the precision model of the machine center is built up with the theory of multi-body system, thus a mathematical model for error sensitivity analysis of four-axis computer numerical control machine tools is established with matrix differential method, finally the key geometric error sources which affect the machining precision are identified after sensitivity coefficient of error are calculated and analyzed. Calculation and example show that geometric error factors of major parts that have relatively significant influence on comprehensive spatial error of the machine tools can be identified effectively, thus important theoretical basis is provided for improving precision of machine tools reasonably and economically.%零部件几何误差耦合而成的机床空间误差是影响其加工精度的主要原因,如何确定各零部件几何误差对加工精度的影响程度从而经济合理地分配机床零部件的几何精度是目前机床设计所面临的一个难题.基于多体系统理论,在敏感度分析的基础上提出一种识别关键性几何误差源参数的新方法.以一台四轴精密卧式加工中心为例,基于多体系统理论构建加工中心的精度模型,并利用矩阵微分法建立四轴数控机床误差敏感度分析的数学模型,通过计算与分析误差敏感度系数,最终识别出影响机床加工精度的关键性几何误差.计算和试验分析表

  17. Application of Krylov Reduction Technique for a Machine Tool Multibody Modelling

    Directory of Open Access Journals (Sweden)

    M. Sulitka

    2014-02-01

    Full Text Available Quick calculation of machine tool dynamic response represents one of the major requirements for machine tool virtual modelling and virtual machining, aiming at simulating the machining process performance, quality, and precision of a workpiece. Enhanced time effectiveness in machine tool dynamic simulations may be achieved by employing model order reduction (MOR techniques of the full finite element (FE models. The paper provides a case study aimed at comparison of Krylov subspace base and mode truncation technique. Application of both of the reduction techniques for creating a machine tool multibody model is evaluated. The Krylov subspace reduction technique shows high quality in terms of both dynamic properties of the reduced multibody model and very low time demands at the same time.

  18. Sine-Bar Attachment For Machine Tools

    Science.gov (United States)

    Mann, Franklin D.

    1988-01-01

    Sine-bar attachment for collets, spindles, and chucks helps machinists set up quickly for precise angular cuts that require greater precision than provided by graduations of machine tools. Machinist uses attachment to index head, carriage of milling machine or lathe relative to table or turning axis of tool. Attachment accurate to 1 minute or arc depending on length of sine bar and precision of gauge blocks in setup. Attachment installs quickly and easily on almost any type of lathe or mill. Requires no special clamps or fixtures, and eliminates many trial-and-error measurements. More stable than improvised setups and not jarred out of position readily.

  19. Sine-Bar Attachment For Machine Tools

    Science.gov (United States)

    Mann, Franklin D.

    1988-01-01

    Sine-bar attachment for collets, spindles, and chucks helps machinists set up quickly for precise angular cuts that require greater precision than provided by graduations of machine tools. Machinist uses attachment to index head, carriage of milling machine or lathe relative to table or turning axis of tool. Attachment accurate to 1 minute or arc depending on length of sine bar and precision of gauge blocks in setup. Attachment installs quickly and easily on almost any type of lathe or mill. Requires no special clamps or fixtures, and eliminates many trial-and-error measurements. More stable than improvised setups and not jarred out of position readily.

  20. CIMT 2003--An attractive gala of world machine tool industry

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ With the support of the Chinese Government and through close cooperation with related machine tool associations from all countries of the world, the China Machine Tool & Tool Builders' Association(CMTBA) has successfully hosted seven times of the China International Machine Tool Show(CIMT). With expanding scales and exhibition of more advanced products, CIMT has become the largest and best- known international machine tool exhibition in China. Domestic and overseas machine tool manufacturers consider CIMT an important venue to demonstrate their new products, conduct technological exchanges, promote trade and seek cooperative and joint venture partners. The 8th China International Machine Tool Show, also known as CIMT 2003, will be held at the China International Exhibition Center in Beijing on April 16 - 22 next year. The organizer of CIMT 2003 has started the work of inviting domestic and overseas machine tool manufacturers to attend the grand exhibition.

  1. Keeping you safe by making machine tools safe

    CERN Multimedia

    2012-01-01

    CERN’s third safety objective for 2012 concerns the safety of equipment - and machine tools in particular.   There are three prerequisites for ensuring that a machine tool can be used safely: ·      the machine tool must comply with Directive 2009/104/EC, ·      the layout of the workshop must be compliant, and ·      everyone who uses the machine tool must be trained. Provided these conditions are met, the workshop head can grant authorisation to use the machine tool. To fulfil this objective, an inventory of the machine tools must be drawn up and the people responsible for them identified. The HSE Unit's Safety Inspection Service produces compliance reports for the machine tools. In order to meet the third objective set by the Director-General, the section has doubled its capacity to carry out inspections: ...

  2. Static and Dynamic Performance Improvement of Conventional Computer Numerical Control Machine Tool Bed with Hybrid Welded Steel

    Directory of Open Access Journals (Sweden)

    S. S. Abuthakeer

    2011-01-01

    Full Text Available Problem statement: The advancements in machine tools to maximize the production by increasing spindle speeds have caused vibration in machine tools. The two functional requirements of machine tool bed for machine tools are high structural stiffness and high damping, which cannot be satisfied simultaneously if conventional metallic materials such as cast iron are employed. Hence there is a need to replace cast iron with alternate materials. Approach: The objective of this study is to improve the stiffness, natural frequency and damping capability of machine tool bed using a composite material containing welded steel and polymer concrete. Welded steel material has high stiffness but low damping and polymer concrete has high damping but low stiffness. So in this study, a machine tool bed made of sandwich structures of welded steel and polymer concrete is designed and manufactured. Modal and static analyses were conducted numerically and experimentally to determine the modal frequencies, damping ratio, deformation and strain. Results: The results at first mode showed that the natural frequency improved by 24.7% and damping ratio was 2.7 times higher than cast iron. The comparison of strain and deformation also showed significant improvement. Conclusion: This study proposed a hybrid welded steel bed as a replacement for cast iron as a machine tool bed material and the results showed that the static and dynamic characteristics were superior to cast iron.

  3. Reducing maintenance costs in agreement with CNC machine tools reliability

    Science.gov (United States)

    Ungureanu, A. L.; Stan, G.; Butunoi, P. A.

    2016-08-01

    Aligning maintenance strategy with reliability is a challenge due to the need to find an optimal balance between them. Because the various methods described in the relevant literature involve laborious calculations or use of software that can be costly, this paper proposes a method that is easier to implement on CNC machine tools. The new method, called the Consequence of Failure Analysis (CFA) is based on technical and economic optimization, aimed at obtaining a level of required performance with minimum investment and maintenance costs.

  4. 基于自适应控制技术的铣削参数优化%Based on Adaptive Control Technology to Manufacture of Machine Tool Research Intelligent

    Institute of Scientific and Technical Information of China (English)

    时政博; 黄筱调; 丁文政; 于春建

    2012-01-01

    采用BP神经网络算法应用于铣齿功率建模能较准确地预测铣齿功率大小,进而运用STATISTICA的正交设计优化试验数据对滚齿机进行再制造,通过在主轴箱加设传感器实现了机床振动稳定性的的在线监控,分析各个切削状态下主轴箱振动同铣削功率的关系,进行优化切削参数,实现了数控系统与在线监控技术的自适应闭环监控.完成了4m大型滚齿机向高速铣齿机床SKX-4000的智能化再制造.结果表明,采用的控制策略能适应强力铣削的工况变化,稳定地控制加工过程,达到保护机床、刀具和提高加工效率的目的.%Using BP neural network theory and algorithms used in milling power modeling studies can more accurately predict the size of milling power, Through orthogonal design optimization of STAT1STI-CA test data for remanufacturing of gear hobbing, adding sensors in the spindle box, the numerical control system and adaptive control technology online monitoring is provided the vibration, Through the analysis of each state of the spindle box vibration cutting with milling power relations, then optimize the cutting parameters,the stability of the adaptive closed-loop is realized. Completed the 4 m large gear hobbing high speed milling gear to the intelligent machine remanufacturing. The results show that the control strategy can adapt to the operation condition of the powerful milling changes, Stability control of the process, protect the machine, tool,and the purpose of improving processing efficiency.

  5. Caracterización Dinámica de Máquinas Herramienta y Diseño de un Sistema Activo de Reducción de Vibraciones durante el Mecanizado Dynamic Characterization of Machine Tool and Design of an Active System for the Reduction of Vibration during Machining

    Directory of Open Access Journals (Sweden)

    E Zamora

    2004-01-01

    Full Text Available En este trabajo se presenta una metodología para la caracterización dinámica de máquinas herramienta, así como una propuesta de sistema de control que permite la reducción de vibraciones durante el proceso de mecanizado utilizando un actuador piezoeléctrico. Esta metodología consta de las siguientes cuatro etapas: identificación de las características dinámicas del sistema, elaboración de un modelo matemático, definición de las características dinámicas del actuador y desarrollo e implantación de la rutina de control. La metodología propuesta fue aplicada en un centro de mecanizado vertical y se midieron los niveles de vibración durante el mecanizado de paredes delgadas en una pieza de aluminio. Se concluye que la metodología propuesta disminuye considerablemente el nivel de vibración presente durante la operación de mecanizado.This work presents a methodology for the dynamic characterization of machine tools, as well as a control system that makes use of a piezoelectric actuator for vibration reduction during the process of machining. The methodology consists of the following four steps: identification of the dynamic characteristic of the system, implementation of a mathematical model, definition of the dynamic characteristics of the actuator and development and installation of the control algorithm. The proposed methodology has been applied in a vertical machining center and the vibration level during the machining of thin walls in an aluminum piece have been measured. It is concluded that the proposed methodology reduces considerably the vibration level present during the milling operation.

  6. Analysis of machining and machine tools

    CERN Document Server

    Liang, Steven Y

    2016-01-01

    This book delivers the fundamental science and mechanics of machining and machine tools by presenting systematic and quantitative knowledge in the form of process mechanics and physics. It gives readers a solid command of machining science and engineering, and familiarizes them with the geometry and functionality requirements of creating parts and components in today’s markets. The authors address traditional machining topics, such as: single and multiple point cutting processes grinding components accuracy and metrology shear stress in cutting cutting temperature and analysis chatter They also address non-traditional machining, such as: electrical discharge machining electrochemical machining laser and electron beam machining A chapter on biomedical machining is also included. This book is appropriate for advanced undergraduate and graduate mechani cal engineering students, manufacturing engineers, and researchers. Each chapter contains examples, exercises and their solutions, and homework problems that re...

  7. 基于ANSYS/WORKBENCH的机床动态性能分析及改进%Analysis and Improvement of Machine Tool Dynamic Performance Based on ANSYS/WORKBENCH

    Institute of Scientific and Technical Information of China (English)

    孙永清; 王永泉; 朱祥; 寸花英

    2012-01-01

    基于Pro/E与ANSYS/WORKBENCH协同仿真及优化的解决方案,建立了某精密卧式加工中心立柱结构的有限元分析模型.以提高其模态频率为目标,进行了结构型式及尺寸参数的优化设计.在考虑结合面单元特性的整机模型中验证优化效果,结果表明:在降低加工中心质量的同时提高了整机结构动刚度.优化设计方法及结果为机床设计提供了重要依据.%Based on Pro/E and ANSYS WORKBENCH co-simulation and optimization platform, the FEM model of the column ofsome precision horizontal machining center was established. To increase natural frequencies, the optimisations of the structure and dimension parameters were perfomsed. The optimal results were validated by testing the virtual model of the whole machining center joining with surface elements. Results show that the quality of the machining center is decreased while the dynamic stiffness of the whole machine is increased. Optimization results provide an important basis for the machine tool design.

  8. 基于Isight的机床结构CAD/CAE集成优化方法研究%Research on the CAD/CAE Integrated Optimization Method of Machine Tool Structures Based on Lsight

    Institute of Scientific and Technical Information of China (English)

    卢健钊; 殷国富; 王玲

    2013-01-01

    在多学科优化集成软件Isight环境中,综合应用SolidEdge参数化建模功能和ANSYS有限元分析功能,建立一种面向数控机床的CAD/CAE集成优化设计框架.提出了采用优化拉丁超立方抽样试验设计、响应面近似模型建模以及智能优化方法,以某卧式加工中心Z向进给系统为研究对象,进行了CAD/CAE集成优化应用验证,并对滑座的几何尺寸参数进行了优化,结果表明提出的集成优化方法是可行的.%Combined the parametric modeling function of SolidEdge with the finite element analysis function of ANSYS, the framework of CNC machine tool oriented CAD/CAE integrated optimization was bulit based on lsight multidisciplinary optimization software. The Z direction feed system of certain horizontal machining center was taken as the research object, the verification of CAD/CAE integrated optimization was carried out by using optimal Latin hypercube sampling, response surface modeling and intelligent optimization method. The geometric dimension parameters of slider were optimized. The results demonstrate the proposed optimization method is feasible.

  9. Identification of Kinematic Errors of Five-axis Machine Tool Trunnion Axis from Finished Test Piece

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ya; FU Jianzhong; CHEN Zichen

    2014-01-01

    Compared with the traditional non-cutting measurement, machining tests can more accurately reflect the kinematic errors of five-axis machine tools in the actual machining process for the users. However, measurement and calculation of the machining tests in the literature are quite difficult and time-consuming. A new method of the machining tests for the trunnion axis of five-axis machine tool is proposed. Firstly, a simple mathematical model of the cradle-type five-axis machine tool was established by optimizing the coordinate system settings based on robot kinematics. Then, the machining tests based on error-sensitive directions were proposed to identify the kinematic errors of the trunnion axis of cradle-type five-axis machine tool. By adopting the error-sensitive vectors in the matrix calculation, the functional relationship equations between the machining errors of the test piece in the error-sensitive directions and the kinematic errors of C-axis and A-axis of five-axis machine tool rotary table was established based on the model of the kinematic errors. According to our previous work, the kinematic errors of C-axis can be treated as the known quantities, and the kinematic errors of A-axis can be obtained from the equations. This method was tested in Mikron UCP600 vertical machining center. The machining errors in the error-sensitive directions can be obtained by CMM inspection from the finished test piece to identify the kinematic errors of five-axis machine tool trunnion axis. Experimental results demonstrated that the proposed method can reduce the complexity, cost, and the time consumed substantially, and has a wider applicability. This paper proposes a new method of the machining tests for the trunnion axis of five-axis machine tool.

  10. Program Design Report of the CNC Machine Tool(II)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Kiun; Youm, K. U.; Kim, K. S.; Lee, I. B.; Yoon, K. B.; Lee, C. K.; Youm, J. H

    2007-06-15

    The application of CNC machine tool being widely expanded according to variety of machine work method and rapid promotion of machine tool, cutting tool, for high speed efficient machine work. In order to conduct of the project of manufacture and maintenance of laboratory equipment, production design and machine work technology are continually developed, especially the application of CNC machine tool is very important for the improvement of productivity, quality and clearing up a manpower shortage. We publish technical report which it includes CNC machine tool program and drawing, it contributes to the systematic development of CNC program design and machine work technology.

  11. Based on the Kansei Engineeringˊs Machine Tool Modelling Design Research%基于感性工学的机床造型设计研究

    Institute of Scientific and Technical Information of China (English)

    张莉

    2015-01-01

    From the perspective of kansei engineering did the research for machine tool modeling design. In the process of re-search,According to the machine tools modeling to collect relevant vocabulary and product kansei image sample pictures,con-struct the mapping model between the perceptual semantic and elements of machine tools modeling,used semantic differential method and quantification theory typeⅠto do analysis of data in the model. The results of the research will provide the basis for machine tools modeling design and design evaluation.%从感性工学的角度研究机床造型设计。在研究过程中,针对机床造型收集相关感性意向语汇和产品样本图,构建感性语意与机床造型要素之间的映射模型,并用语意差异法和数量化理论Ⅰ对模型中的数据进行处理分析。研究结果将为指导机床造型设计与设计评价提供依据。

  12. 基于 SAS 机床行业发展的数量化研究%Quantification Study of the Development of the Machine Tool Industry Based on SAS

    Institute of Scientific and Technical Information of China (English)

    翟芳婷

    2014-01-01

    Obtained large historical data of 11 typical industry and six machine tool companies from the stock market by using SAS software ,we get a mathematical formula about the development of machine tool industry by SAS programming , principal component analysis method and multivariate linear regression analysis method .This formula reflects the relationship between the development of machine tool industry and the national economy ,infrastructure ,the real estate .The study pro-vide a reference for the future development and investment of machine tool industry .%利用SAS软件从证券市场上获取11个典型行业和6家机床公司2008~2013年的庞大经济数据,通过SAS编程借助主成份分析法和多元线性回归分析法建立了影响机床行业发展的模型方程,数量化阐述了机床行业发展指数与国民经济、基础设施和房地产三者发展的关系,为机床行业的未来发展及投资提供借鉴。

  13. DRIVE AND CONTROL OF VIRTUAL-AXIS NC MACHINE TOOLS

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The structure features and driving modes of virtual-axis NC machine tools are studied.Accor- ding to different application requirements,the three-axis control method,the five-axis control method and the six-freedom control method are put forward.These results lay a foundation for the product development of the virtual-axis NC machine tools.

  14. Influence of Process and Machine tool on tolerance

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo

    This note gives a summary of how the process and the machine tool can influence the geometrical tolerances. The note concerns cutting processes and machine tools but many of the considerations can be transferred directly to other types of manufacturing process and machines....

  15. Research on steel-fibber polymer concrete machine tool structure

    Institute of Scientific and Technical Information of China (English)

    XU Ping; YU Ying-hua

    2008-01-01

    Researched on the design and manufacturing of machine tool bed made by Steel-fibber Polymer Concrete(SFPC),which analyzed the static,dynamic and thermal performances of the bed.The results of study prove that machine tool bed made with SFPC is much more superiority than made in cast iron in dynamic and thermal performances,and is more superiority then made in Polymer Concrete (PC) in static performances.It can be concluded that the static,dynamic and thermal properties of machine tool can be improved by manufacturing machine tool bed with SFPC.Also SFPC machine tool bed posses some other advantages in the following: short development time,simple production process,reducing cost cost,saving energy,iron and steel.

  16. Research on steel-fibber polymer concrete machine tool structure

    Institute of Scientific and Technical Information of China (English)

    XU Ping; YU Ying-hua

    2008-01-01

    Researched on the design and manufacturing of machine tool bed made by Steel-fibber Polymer Concrete(SFPC), which analyzed the static, dynamic and thermal performances of the bed. The results of study prove that machine tool bed made with SFPC is much more superiority than made in cast iron in dynamic and thermal perform-ances, and is more superiority then made in Polymer Concrete (PC) in static perform-ances. It can be concluded that the static, dynamic and thermal properties of machine tool can be improved by manufacturing machine tool bed with SFPC. Also SFPC machine tool bed posses some other advantages in the following: short development time, simple pro-duction process, reducing cost cost, saving energy, iron and steel.

  17. Research on assembly reliability control technology for computer numerical control machine tools

    Directory of Open Access Journals (Sweden)

    Yan Ran

    2017-01-01

    Full Text Available Nowadays, although more and more companies focus on improving the quality of computer numerical control machine tools, its reliability control still remains as an unsolved problem. Since assembly reliability control is very important in product reliability assurance in China, a new key assembly processes extraction method based on the integration of quality function deployment; failure mode, effects, and criticality analysis; and fuzzy theory for computer numerical control machine tools is proposed. Firstly, assembly faults and assembly reliability control flow of computer numerical control machine tools are studied. Secondly, quality function deployment; failure mode, effects, and criticality analysis; and fuzzy theory are integrated to build a scientific extraction model, by which the key assembly processes meeting both customer functional demands and failure data distribution can be extracted, also an example is given to illustrate the correctness and effectiveness of the method. Finally, the assembly reliability monitoring system is established based on key assembly processes to realize and simplify this method.

  18. MODELING AND COMPENSATION TECHNIQUE FOR THE GEOMETRIC ERRORS OF FIVE-AXIS CNC MACHINE TOOLS

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    One of the important trends in precision machining is the development of real-time error compensation technique.The error compensation for multi-axis CNC machine tools is very difficult and attractive.The modeling for the geometric error of five-axis CNC machine tools based on multi-body systems is proposed.And the key technique of the compensation-identifying geometric error parameters-is developed.The simulation of cutting workpiece to verify the modeling based on the multi-body systems is also considered.

  19. Active Control of Machine Tool Chatter

    OpenAIRE

    Håkansson, Lars; Claesson, Ingvar; Lagö, Thomas L.

    1999-01-01

    In the turning operation chatter or vibration is a frequent problem, which affects the result of the machining, and, in particular, the surface finish. Tool life is also influenced by vibration. Severe acoustic noise in the working environment frequently occurs as a result of dynamic motion between the cutting tool and the workpiece. By proper machine design, e.g. improved stiffness of the machine structure, the problem of relative dynamic motion between cutting tool and workpiece may be part...

  20. A Two-stage Tuning Method of Servo Parameters for Feed Drives in Machine Tools

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the evaluation of dynamic performance for feed drives in machine tools, this paper presents a two-stage tuning method of servo parameters. In the first stage, the evaluation of dynamic performance, parameter tuning and optimization on a mechatronic integrated system simulation platform of feed drives are performed. As a result, a servo parameter combination is acquired. In the second stage, the servo parameter combination from the first stage is set and tuned further in a real machine tool whose dynamic performance is measured and evaluated using the cross grid encoder developed by Heidenhain GmbH. A case study shows that this method simplifies the test process effectively and results in a good dynamic performance in a real machine tool.

  1. Development of meso-scale milling machine tool and its performance analysis

    Institute of Scientific and Technical Information of China (English)

    Hongtao LI; Xinmin LAI; Chengfeng LI; Zhongqin LIN; Jiancheng MIAO; Jun NI

    2008-01-01

    To overcome the shortcomings of current technologies for meso-scale manufacturing such as MEMS and ultra precision machining, this paper focuses on the investigations on the meso milling process with a miniaturized machine tool. First, the related technologies for the process mechanism studies are investigated based on the analysis of the characteristics of the meso milling process. An overview of the key issues is presented and research approaches are also proposed. Then, a meso-scale milling machine tool system is developed. The subsystems and their specifications are described in detail. Finally, some tests are conducted to evaluate the performance of the system. These tests consist of precision measurement of the positioning subsystem, the test for machining precision evaluation, and the experiments for machining mechanical parts with com-plex features. Through test analysis, the meso milling process with a miniaturized machine tool is proved to be feasible and applicable for meso manufacturing.

  2. Research of Ultrasonic Testing System for NC Machine Tool Based on Virtual Instrument%基于虚拟仪器的数控机床超声检测系统研究

    Institute of Scientific and Technical Information of China (English)

    陈肖芬; 张吉堂

    2014-01-01

    按照虚拟仪器的开发思路,设计了数控机床超声检测系统的硬件结构,利用LabVIEW平台设计完成了系统的前面板和程序框图,实现了工件在数控加工过程中的在线检测功能。%According to the development idea of virtual instrument,the hardware structure of the ultrasonic testing (UT)system for numerical control (NC)machine tool was designed,and the front panel and diagram program of the system was completed by using platform of LabVIEW. It realizes the on-line UT of workpiece in the machining process of NC machine tool.

  3. Design principles of metal-cutting machine tools

    CERN Document Server

    Koenigsberger, F

    1964-01-01

    Design Principles of Metal-Cutting Machine Tools discusses the fundamentals aspects of machine tool design. The book covers the design consideration of metal-cutting machine, such as static and dynamic stiffness, operational speeds, gearboxes, manual, and automatic control. The text first details the data calculation and the general requirements of the machine tool. Next, the book discusses the design principles, which include stiffness and rigidity of the separate constructional elements and their combined behavior under load, as well as electrical, mechanical, and hydraulic drives for the op

  4. Non-contact measurement and analysis of machine tool spindles

    OpenAIRE

    Clough, David A; Fletcher, Simon; Longstaff, Andrew P.

    2010-01-01

    Increasing demand on the manufacturing industry to produce tighter tolerance parts means it is\\ud necessary to gain a greater understanding of machine tool capabilities and error sources. A significant source of machine tool errors is down to spindle inaccuracies and performance, leading to part scrapping. Catastrophic spindle failure brings production to a standstill until a new spindle can be procured and installed, resulting in lost production time.\\ud This project aims to assess the effec...

  5. Thermal Analysis for Condition Monitoring of Machine Tool Spindles

    Science.gov (United States)

    Clough, D.; Fletcher, S.; Longstaff, A. P.; Willoughby, P.

    2012-05-01

    Decreasing tolerances on parts manufactured, or inspected, on machine tools increases the requirement to have a greater understanding of machine tool capabilities, error sources and factors affecting asset availability. Continuous usage of a machine tool during production processes causes heat generation typically at the moving elements, resulting in distortion of the machine structure. These effects, known as thermal errors, can contribute a significant percentage of the total error in a machine tool. There are a number of design solutions available to the machine tool builder to reduce thermal error including, liquid cooling systems, low thermal expansion materials and symmetric machine tool structures. However, these can only reduce the error not eliminate it altogether. It is therefore advisable, particularly in the production of high value parts, for manufacturers to obtain a thermal profile of their machine, to ensure it is capable of producing in tolerance parts. This paper considers factors affecting practical implementation of condition monitoring of the thermal errors. In particular is the requirement to find links between temperature, which is easily measureable during production and the errors which are not. To this end, various methods of testing including the advantages of thermal images are shown. Results are presented from machines in typical manufacturing environments, which also highlight the value of condition monitoring using thermal analysis.

  6. 基于统计学方法的数控机床感性意象研究%Research of CNC machine tools kansei based on statistical methods

    Institute of Scientific and Technical Information of China (English)

    胡志刚; 魏雪婷; 乔现玲; 李阳; 樊佳爽

    2014-01-01

    In order to meet the kansei needs of the user better ,the study tries to find a new CNC style design way ,through combi-ning statistical methods and quantitative theoryⅠof kansei engineering .After surveying the kansei image words of CNC machine tools,Multidimensional Scaling (MDS) analysis and K-mean Cluster Analysis (CA) were used to group the words and extract the representative kansei image words of CNC machine .Collected 29 representative pictures of CNC machine tools ,pareto chart was used to find the main style design elements of CNC machine tools .The regression relationship model of the kansei image and the design elements was found after using quantitative theory Ⅰand statistical method .The results of experiment is helpful to the ac-curate design of CNC machine tools ,and benefits the study of Product Identity (PI)building.%采用统计学方法,结合感性工学数量化理论Ⅰ对数控机床的造型意象开展设计研究,得到更符合用户感性需求的数控机床造型。在调研数控机床感性意象词汇的基础上,运用多维尺度分析法和K-mean聚类分析将数控机床的感性意象词汇进行分群,并提取具有代表性的感性意象词汇。通过调研搜集29个具有代表性的数控机床造型图片,运用帕累托图对数控机床的造型设计要素进行提取。运用数量化理论Ⅰ研究消费者的感性意象与数控机床设计要素的关系,并建立相应的数学分析模型,有助于数控机床的精准化设计,并为产品的形象识别( Product Identity ,PI)设计提供参考。

  7. Determination of real machine-tool settings and minimization of real surface deviation by computerized inspection

    Science.gov (United States)

    Litvin, Faydor L.; Kuan, Chihping; Zhang, YI

    1991-01-01

    A numerical method is developed for the minimization of deviations of real tooth surfaces from the theoretical ones. The deviations are caused by errors of manufacturing, errors of installment of machine-tool settings and distortion of surfaces by heat-treatment. The deviations are determined by coordinate measurements of gear tooth surfaces. The minimization of deviations is based on the proper correction of initially applied machine-tool settings. The contents of accomplished research project cover the following topics: (1) Descriptions of the principle of coordinate measurements of gear tooth surfaces; (2) Deviation of theoretical tooth surfaces (with examples of surfaces of hypoid gears and references for spiral bevel gears); (3) Determination of the reference point and the grid; (4) Determination of the deviations of real tooth surfaces at the points of the grid; and (5) Determination of required corrections of machine-tool settings for minimization of deviations. The procedure for minimization of deviations is based on numerical solution of an overdetermined system of n linear equations in m unknowns (m much less than n ), where n is the number of points of measurements and m is the number of parameters of applied machine-tool settings to be corrected. The developed approach is illustrated with numerical examples.

  8. Process planning optimization on turning machine tool using a hybrid genetic algorithm with local search approach

    Directory of Open Access Journals (Sweden)

    Yuliang Su

    2015-04-01

    Full Text Available A turning machine tool is a kind of new type of machine tool that is equipped with more than one spindle and turret. The distinctive simultaneous and parallel processing abilities of turning machine tool increase the complexity of process planning. The operations would not only be sequenced and satisfy precedence constraints, but also should be scheduled with multiple objectives such as minimizing machining cost, maximizing utilization of turning machine tool, and so on. To solve this problem, a hybrid genetic algorithm was proposed to generate optimal process plans based on a mixed 0-1 integer programming model. An operation precedence graph is used to represent precedence constraints and help generate a feasible initial population of hybrid genetic algorithm. Encoding strategy based on data structure was developed to represent process plans digitally in order to form the solution space. In addition, a local search approach for optimizing the assignments of available turrets would be added to incorporate scheduling with process planning. A real-world case is used to prove that the proposed approach could avoid infeasible solutions and effectively generate a global optimal process plan.

  9. Reliability assessment of numerical control machine tools with whole lifecycle based on bounded bathtub intensity process%基于边界浴盆强度过程的数控机床全寿命周期可靠性评估

    Institute of Scientific and Technical Information of China (English)

    任丽娜; 任帅; 王先芝; 刘宇

    2014-01-01

    This paper presented a reliability assessment method for numerical control machine tool based on bounded bathtub in-tensity process (BBIP)model.The method can assess the whole lifecycle reliability of numerical control (NC)machine tools in minimal repair.Bounded bathtub intensity function of failure times was built,and a formula for calculating the lasting time of ear-ly failure period was derived.The maximum likelihood estimation (MLE)for model parameters and reliability indices were given. The failure process of a single NC machine tool with failure truncation was analyzed.The results show that the lasting time of early failure period for NC machine tool is about 5 months.The estimated time is basically consistent with the actual situation.It is demonstrated that BBIP model can accurately evaluate the lasting time of early failure period and can provide a theoretical basis for improving the reliability of NC machine tools.%在最小维修情况下,为实现数控机床的全寿命周期可靠性评估,提出基于边界浴盆强度过程(bounded bathtub intensity process,BBIP)模型的数控机床可靠性评估方法。建立了故障时间的边界浴盆强度函数式,推导了早期故障期持续时间的计算公式,并给出了模型参数和可靠性指标的极大似然点估计。采用该评估方法分析了单台数控机床故障截尾的故障过程,结果表明:该数控机床早期故障期的持续时间大约为5个月,与机床的实际情况基本一致,说明BBIP模型可准确地评估早期故障期的持续时间,为提高机床可靠性提供了一定的理论依据。

  10. Study on Identification of Error for the NC Machine Tools Based on Laser Doppler Anemometer%基于激光多普勒仪的数控机床误差辨识

    Institute of Scientific and Technical Information of China (English)

    甘彬; 刘洋; 赵宇

    2013-01-01

    In response to laser Doppler anemometer characteristics of high precision linear displacement measurement of CNC machine tools, this paper introduced the use of laser Doppler anemometer on the NC machine tool error detection and identification method, explained the identification principle in detail and set up the method of error detection model. In order to reduce the machine error, we provide measurement method and basis of the compensation.%针对激光多普勒仪对数控机床线位移测量精度高的特点,介绍了利用激光多普勒仪对数控机床进行误差检测和辨识的方法,阐述了该方法的几何误差辨识原理,并建立了基于该方法的误差检测数学模型.为减小机床误差提供了测量方法和补偿依据.

  11. FFT and Wavelet-Based Analysis of the Influence of Machine Vibrations on Hard Turned Surface Topographies

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    With hard turning, which is an attractive alternative to existing grinding processes, surface quality is of great importance. Signal processing techniques were used to relate workpiece surface topography to the dynamic behavior of the machine tool. Spatial domain frequency analyses based on fast Fourier transform were used to analyze the tool behavior. Wavelet reconstruction was used for profile filtering. The results show that machine vibration remarkably affects the surface topography at small feed rates, but has negligible effect at high feed rates. The analyses also show how to control the surface quality during hard turning.

  12. Intelligent machine tools. Kosaku kikai no intelligent ka

    Energy Technology Data Exchange (ETDEWEB)

    Moriwaki, T. (Kobe Univ., Kobe (Japan). Faculty of Engineering)

    1993-12-05

    A background of the trend to equip machine tools with intelligence is reviewed and the outline of intelligent machine tools that are now in the process of research and development is surveyed. The flexible manufacturing system (FMS) that was born in the process of automation of machine manufacturing has been proved, in fact, inflexible in the hierarchical structure of information system. This directs attention of transferring to an autonomous and dispersed manufacturing system. In the system, structural components such as machine tools are required to be highly intelligent enough to produce things, while deciding their will autonomously according to their own criteria in cooperation with other components and attempting to optimize the system. The hardware of intelligent machine tools consists of an interface part to intermediate between machines and computers or human, a core system of center of intelligence, and a machine tool part responsible to process things actually. As to processing of information and movement, they consist of processing parts of pre-process, in-process and post-process. A brief introduction is given on their basic functions and on the present state of related researches. 8 refs., 4 figs.

  13. STUDY ON NEW METHOD OF IDENTIFYING GEOMETRIC ERROR PARAMETERS FOR NC MACHINE TOOLS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The methods of identifying geometric error parameters for NC machine tools are introduced. According to analyzing and comparing the different methods, a new method-displacement method with 9 lines is developed based on the theories of the movement errors of multibody system (MBS). A lot of experiments are also made to obtain 21 terms geometric error parameters by using the error identification software based on the new method.

  14. Forbidden Zones for Numerically-Controlled Machine Tools

    Science.gov (United States)

    Philpot, D.

    1986-01-01

    Computer-controlled machine tool prevented from striking and damaging protruding members on workpiece by creating forbidden zone in control program. With aid of computer graphics, tool profile and coordinates of forbidden zone digitized and stored in computer memory as part of tool path.

  15. Educational Resources for the Machine Tool Industry. Executive Summary.

    Science.gov (United States)

    Texas State Technical Coll. System, Waco.

    This document describes the MASTER (Machine Tool Advanced Skills Educational Resources) program, a geographic partnership of seven of the nation's best 2-year technical and community colleges located in seven states. The project developed and disseminated a national training model for manufacturing processes and new technologies within the…

  16. Standardized Curriculum for Machine Tool Operation/Machine Shop.

    Science.gov (United States)

    Mississippi State Dept. of Education, Jackson. Office of Vocational, Technical and Adult Education.

    Standardized vocational education course titles and core contents for two courses in Mississippi are provided: machine tool operation/machine shop I and II. The first course contains the following units: (1) orientation; (2) shop safety; (3) shop math; (4) measuring tools and instruments; (5) hand and bench tools; (6) blueprint reading; (7)…

  17. Job Grading Standard for Machine Tool Operator, WG-3431.

    Science.gov (United States)

    Civil Service Commission, Washington, DC. Bureau of Policies and Standards.

    The standard covers nonsupervisory work involved in the set up, adjustment, and operation of conventional machine tools to perform machining operations in the manufacture and repair of castings, forgings, or parts from raw stock made of various metals, metal alloys, and other materials. A general description of the job at both the WG-8 and WG-9…

  18. Volumetric verification of multiaxis machine tool using laser tracker.

    Science.gov (United States)

    Aguado, Sergio; Samper, David; Santolaria, Jorge; Aguilar, Juan José

    2014-01-01

    This paper aims to present a method of volumetric verification in machine tools with linear and rotary axes using a laser tracker. Beyond a method for a particular machine, it presents a methodology that can be used in any machine type. Along this paper, the schema and kinematic model of a machine with three axes of movement, two linear and one rotational axes, including the measurement system and the nominal rotation matrix of the rotational axis are presented. Using this, the machine tool volumetric error is obtained and nonlinear optimization techniques are employed to improve the accuracy of the machine tool. The verification provides a mathematical, not physical, compensation, in less time than other methods of verification by means of the indirect measurement of geometric errors of the machine from the linear and rotary axes. This paper presents an extensive study about the appropriateness and drawbacks of the regression function employed depending on the types of movement of the axes of any machine. In the same way, strengths and weaknesses of measurement methods and optimization techniques depending on the space available to place the measurement system are presented. These studies provide the most appropriate strategies to verify each machine tool taking into consideration its configuration and its available work space.

  19. Critical Technology Assessment of Five Axis Simultaneous Control Machine Tools

    Science.gov (United States)

    2009-07-01

    some of the less traditional end-uses cited in export license applications for these particular machine tools include the manufacture of artificial ... insemination equipment for cattle and the manufacture of moulds for the soles of shoes. C. Military Applications According to DOD’s Military

  20. Hard turning micro-machine tool

    Science.gov (United States)

    DeVor, Richard E; Adair, Kurt; Kapoor, Shiv G

    2013-10-22

    A micro-scale apparatus for supporting a tool for hard turning comprises a base, a pivot coupled to the base, an actuator coupled to the base, and at least one member coupled to the actuator at one end and rotatably coupled to the pivot at another end. A tool mount is disposed on the at least one member. The at least one member defines a first lever arm between the pivot and the tool mount, and a second lever arm between the pivot and the actuator. The first lever arm has a length that is less than a length of the second lever arm. The actuator moves the tool mount along an arc.

  1. Age, diversification and survival in the German machine tool industry, 1953-2002

    OpenAIRE

    Coad, Alex; Guenther, Christina

    2011-01-01

    We focus on the relationship of age and diversification patterns of German machine tool manufacturers in the post war era. Based on trade journals we track the entire firm populations' product portfolio development throughout each firm's lifetime. We distinguish between 'minor diversification' and 'major diversification', where these two concepts refer to adding a new product variation within a familiar submarket, or expanding the product portfolio into new submarkets. Our analysis reveals fo...

  2. Imperfect preventive maintenance for numerical control machine tools with log-linear virtual age process

    Institute of Scientific and Technical Information of China (English)

    郭俊锋; 芮执元; 冯瑞成; 魏兴春

    2014-01-01

    Based on the log-linear virtual age process, an imperfect preventive maintenance policy for numerical control (NC) machine tools with random maintenance quality is proposed. The proposed model is a combination of the Kijima type virtual age model and the failure intensity adjustment model. Maintenance intervals of the proposed hybrid model are derived when the failure intensity increase factor and the restoration factor are both random variables with uniform distribution. The optimal maintenance policy in infinite time horizon is presented. A numerical example is given when the failures of NC machine tools are described by the log-linear process. Finally, a discussion is presented to show how the optimal results depend on the different cost parameters.

  3. Optimization of Operation Sequence in CNC Machine Tools Using Genetic Algorithm

    Science.gov (United States)

    Abu Qudeiri, Jaber; Yamamoto, Hidehiko; Ramli, Rizauddin

    The productivity of machine tools is significantly improved by using microcomputer based CAD/CAM systems for NC program generation. Currently, many commercial CAD/CAM packages that provide automatic NC programming have been developed and applied to various cutting processes. Many cutting processes machined by CNC machine tools. In this paper, we attempt to find an efficient solution approach to determine the best sequence of operations for a set of operations that located in asymmetrical locations and different levels. In order to find the best sequence of operations that achieves the shortest cutting tool travel path (CTTP), genetic algorithm is introduced. After the sequence is optimized, the G-codes that use to code for the travel time is created. CTTP can be formulated as a special case of the traveling salesman problem (TSP). The incorporation of genetic algorithm and TSP can be included in the commercial CAD/CAM packages to optimize the CTTP during automatic generation of NC programs.

  4. Development of Prediction System for Environmental Burden for Machine Tool Operation

    Science.gov (United States)

    Narita, Hirohisa; Kawamura, Hiroshi; Norihisa, Takashi; Chen, Lian-Yi; Fujimoto, Hideo; Hasebe, Takao

    Recently, some activities for environmental protection have been attempted to reduce environmental burdens in many fields. The manufacturing field also requires such reduction. Hence, a prediction system for environmental burden for machining operation is proposed based on the Life Cycle Assessment (LCA) policy for the future manufacturing system in this research. This system enables the calculation of environmental burden (equivalent CO2 emission) due to the electric consumption of machine tool components, cutting tool status, coolant quantity, lubricant oil quantity and metal chip quantity, and provides accurate information of environmental burden of the machining process by considering some activities related to machine tool operation. In this paper, the development of the prediction system is described. As a case study, two Numerical Control (NC) programs that manufacture a simple shape are evaluated to show the feasibility of the proposed system.

  5. Bayesian networks modeling for thermal error of numerical control machine tools

    Institute of Scientific and Technical Information of China (English)

    Xin-hua YAO; Jian-zhong FU; Zi-chen CHEN

    2008-01-01

    The interaction between the heat source location,its intensity,thermal expansion coefficient,the machine system configuration and the running environment creates complex thermal behavior of a machine tool,and also makes thermal error prediction difficult.To address this issue,a novel prediction method for machine tool thermal error based on Bayesian networks (BNs) was presented.The method described causal relationships of factors inducing thermal deformation by graph theory and estimated the thermal error by Bayesian statistical techniques.Due to the effective combination of domain knowledge and sampled data,the BN method could adapt to the change of running state of machine,and obtain satisfactory prediction accuracy.Ex-periments on spindle thermal deformation were conducted to evaluate the modeling performance.Experimental results indicate that the BN method performs far better than the least squares(LS)analysis in terms of modeling estimation accuracy.

  6. The effect of geometric structure on stiffness and damping factor of wood applicable to machine tool structure

    Directory of Open Access Journals (Sweden)

    Susilo Adi Widyanto

    2013-06-01

    Full Text Available Stiffness and vibration damping capability are important criteria in design of machine tool structure. In other sides, the weight of machine tool structure must be reduced to increase  the handling capability. This paper presents  an analysis of the effect of geometric structure on stiffness and vibration damping of wood structure.  The stiffness was analysed  using numerical method, so called finite element method (FEM, while the vibration damping capability was experimentally tested. Vibration testing was also performed to wood structures with sand powder filled  into  its rectangular hole to observe the its effect on damping factor. Simulation results show  that the cross ribs structure yielded minimum mass reduction ratio compared to the three square holes as well as the single rectangular hole structures. While the vibration test results explained that the damping factor of Shorea laevis wood was higher than that Hevea braziiensis wood. The use of sand powder as vibrating  mass in closed-box structure effectively increased the damping capability, for single rectangular hole structure the damping factor was increased from 0.048 to 0.079doi: http://dx.doi.org/10.12777/ijse.4.2.2013.57-60[How to cite the article: Widyanto, S. A., Widodo, A., Nugroho, S., & Siahaan, D. (2013. The effect of geometric structure on stiffness and damping factor of wood applicable to machine tool structure. INTERNATIONAL JOURNAL OF SCIENCE AND ENGINEERING, 4(2, 57-60. doi: http://dx.doi.org/10.12777/ijse.4.2.2013.57-60

  7. Development of atmospheric pressure plasma processing machine tool for large aperture optics

    Science.gov (United States)

    Su, Xing; Wu, Yangong; Zhang, Peng; Xin, Qiang; Wang, Bo

    2016-10-01

    In recent years, major projects, such as National Ignition Facility and Laser Mégajoule, have generated great demands for large aperture optics with high surface accuracy and low Subsurface Damage (SSD) at the mean time. In order to remove SSD and improve surface quality, optics is fabricated by sub-aperture polishing. However, the efficiency of the sub-aperture polishing has been a bottleneck step for the optics manufacturing. Atmospheric Pressure Plasma Processing (APPP) as an alternate method offers high potential for speeding up the polishing process. This technique is based on chemical etching, hence there is no physical contact and no damage is induced. In this paper, a fast polishing machine tool is presented which is designed for fast polishing of the large aperture optics using APPP. This machine tool employs 3PRS-XY hybrid structure as its framework. There is a platform in the 3PRS parallel module to support the plasma generating system. And the large work piece is placed on the XY stage. In order to realize the complex motion trajectory for polishing the freeform optics, five axis of the tool operate simultaneously. To overcome the complexity of inverse kinematics calculation, a dedicated motion control system is also designed for speeding up the motion response. For high removal rate, the individual influence of several key processing parameters is investigated. And under specific production condition, this machine tool offers a high material over 30mm3/min for fused silica substrates. This results shows that APPP machine tool has a strong potential for fast polishing large optics without introducing SSD.

  8. Design for Vibrator Field Experiment Based- on Vibrator- earth System

    Institute of Scientific and Technical Information of China (English)

    Chen Zubin; Lin Jun; Liang Tiecheng; Zhang Linhang

    2000-01-01

    vibrator base plate signal, the model was proved to be true. The exploration research on PHVS made a first step on its following optimal design.

  9. An integrated multidisciplinary design optimization method for computer numerical control machine tool development

    Directory of Open Access Journals (Sweden)

    Zaifang Zhang

    2015-02-01

    Full Text Available Computer numerical control machine tool is a typical complex product related with multidisciplinary fields, complex structure, and high-performance requirements. It is difficult to identify the overall optimal solution of the machine tool structure for their multiple objectives. A new integrated multidisciplinary design optimization method is then proposed by using a Latin hypercube sampling, a Kriging approximate model, and a multi-objective genetic algorithm. Design space and parametric model are built by choosing appropriate design variables and their value ranges. Samples in design space are generated by optimal Latin hypercube method, and design variable contributions for design performance are discussed for aiding the designer’s judgments. The Kriging model is built by using polynomial approximation according to the response outputs of these samples. The multidisciplinary design model is established based on three optimization objectives, that is, setting mass, optimum deformation, and first-order natural frequency, and two constraints, that is, second-order natural frequency and third-order natural frequency. The optimal solution is identified by using a multi-objective genetic algorithm. The proposed method is applied in a multidisciplinary optimization case study for a typical computer numerical control machine tool. In the optimal solution, the mass decreases by 3.35% and the first-order natural frequency increases by 4.34% in contrast to the original solution.

  10. Spindle Thermal Error Optimization Modeling of a Five-axis Machine Tool

    Institute of Scientific and Technical Information of China (English)

    Qianjian GUO; Shuo FAN; Rufeng XU; Xiang CHENG; Guoyong ZHAO; Jianguo YANG

    2017-01-01

    Aiming at the problem of low machining accuracy and uncontrollable thermal errors of NC machine tools,spindle thermal error measurement,modeling and compensation of a two turntable five-axis machine tool are researched.Measurement experiment of heat sources and thermal errors are carried out,and GRA(grey relational analysis) method is introduced into the selection of temperature variables used for thermal error modeling.In order to analyze the influence of different heat sources on spindle thermal errors,an ANN (artificial neural network) model is presented,and ABC(artificial bee colony) algorithm is introduced to train the link weights of ANN,a new ABCNN(Artificial bee colony-based neural network) modeling method is proposed and used in the prediction of spindle thermal errors.In order to test the prediction performance of ABC-NN model,an experiment system is developed,the prediction results of LSR (least squares regression),ANN and ABC-NN are compared with the measurement results of spindle thermal errors.Experiment results show that the prediction accuracy of ABC-NN model is higher than LSR and ANN,and the residual error is smaller than 3 μm,the new modeling method is feasible.The proposed research provides instruction to compensate thermal errors and improve machining accuracy of NC machine tools.

  11. Spindle Thermal Error Optimization Modeling of a Five-axis Machine Tool

    Science.gov (United States)

    Guo, Qianjian; Fan, Shuo; Xu, Rufeng; Cheng, Xiang; Zhao, Guoyong; Yang, Jianguo

    2017-03-01

    Aiming at the problem of low machining accuracy and uncontrollable thermal errors of NC machine tools, spindle thermal error measurement, modeling and compensation of a two turntable five-axis machine tool are researched. Measurement experiment of heat sources and thermal errors are carried out, and GRA(grey relational analysis) method is introduced into the selection of temperature variables used for thermal error modeling. In order to analyze the influence of different heat sources on spindle thermal errors, an ANN (artificial neural network) model is presented, and ABC(artificial bee colony) algorithm is introduced to train the link weights of ANN, a new ABC-NN(Artificial bee colony-based neural network) modeling method is proposed and used in the prediction of spindle thermal errors. In order to test the prediction performance of ABC-NN model, an experiment system is developed, the prediction results of LSR (least squares regression), ANN and ABC-NN are compared with the measurement results of spindle thermal errors. Experiment results show that the prediction accuracy of ABC-NN model is higher than LSR and ANN, and the residual error is smaller than 3 μm, the new modeling method is feasible. The proposed research provides instruction to compensate thermal errors and improve machining accuracy of NC machine tools.

  12. High Accuracy On-line Measurement Method of Motion Error on Machine Tools Straight-going Parts

    Institute of Scientific and Technical Information of China (English)

    苏恒; 洪迈生; 魏元雷; 李自军

    2003-01-01

    Harmonic suppression, non-periodic and non-closing in straightness profile error that will bring about harmonic component distortion in measurement result are analyzed. The countermeasure-a novel accurate two-probe method in time domain is put forward to measure straight-going component motion error in machine tools based on the frequency domain 3-point method after symmetrical continuation of probes' primitive signal. Both straight-going component motion error in machine tools and the profile error in workpiece that is manufactured on this machine can be measured at the same time. The information is available to diagnose the fault origin of machine tools. The analysis result is proved to be correct by the experiment.

  13. Series Design of Large-Scale NC Machine Tool

    Institute of Scientific and Technical Information of China (English)

    TANG Zhi

    2007-01-01

    Product system design is a mature concept in western developed countries. It has been applied in war industry during the last century. However, up until now, functional combination is still the main method for product system design in China. Therefore, in terms of a concept of product generation and product interaction we are in a weak position compared with the requirements of global markets. Today, the idea of serial product design has attracted much attention in the design field and the definition of product generation as well as its parameters has already become the standard in serial product designs. Although the design of a large-scale NC machine tool is complicated, it can be further optimized by the precise exercise of object design by placing the concept of platform establishment firmly into serial product design. The essence of a serial product design has been demonstrated by the design process of a large-scale NC machine tool.

  14. A general thermal model of machine tool spindle

    Directory of Open Access Journals (Sweden)

    Yanfang Dong

    2017-01-01

    Full Text Available As the core component of machine tool, the thermal characteristics of the spindle have a significant influence on machine tool running status. Lack of an accurate model of the spindle system, particularly the model of load–deformation coefficient between the bearing rolling elements and rings, severely limits the thermal error analytic precision of the spindle. In this article, bearing internal loads, especially the function relationships between the principal curvature difference F(ρ and auxiliary parameter nδ, semi-major axis a, and semi-minor axis b, have been determined; furthermore, high-precision heat generation combining the heat sinks in the spindle system is calculated; finally, an accurate thermal model of the spindle was established. Moreover, a conventional spindle with embedded fiber Bragg grating temperature sensors has been developed. By comparing the experiment results with simulation, it indicates that the model has good accuracy, which verifies the reliability of the modeling process.

  15. Configuration Design of Product Service System for CNC Machine Tools

    OpenAIRE

    Zhongqi Sheng; Tao Xu; Junyou Song

    2015-01-01

    Product service system is a combination of product and services to meet the customer requirements. Configuration design is the key process of product service system development. This paper studies the configuration design of product service system for CNC machine tools. The research explores the configuration design process of product service system development, analyzes the retrieval method of product service system schemes, determines the configuration sequence of product modules and servic...

  16. Editing of EIA coded, numerically controlled, machine tool tapes

    Science.gov (United States)

    Weiner, J. M.

    1975-01-01

    Editing of numerically controlled (N/C) machine tool tapes (8-level paper tape) using an interactive graphic display processor is described. A rapid technique required for correcting production errors in N/C tapes was developed using the interactive text editor on the IMLAC PDS-ID graphic display system and two special programs resident on disk. The correction technique and special programs for processing N/C tapes coded to EIA specifications are discussed.

  17. Design of a novel parallel reconfigurable machine tool

    CSIR Research Space (South Africa)

    Modungwa, D

    2008-06-01

    Full Text Available equipment, with high stiffness. Each worn out mould or die has different defects, which requires different mechanical processing and positioning of the reconditioning tools. Conventional machine tools and serial manipulators have been found incapable... and philosophy of re-configurability. The structure is influenced by 1) specifications for the repair and re- conditioning of moulds and dies, and 2) the manufacturing processes involved. 1. INTRODUCTION Serial manipulators have been used extensively...

  18. ANALYTICAL MODEL OF CALCULUS FOR INFLUENCE THE TRANSLATION GUIDE WEAR OVER THE MACHINING ACCURACY ON THE MACHINE TOOL

    Directory of Open Access Journals (Sweden)

    Ivona PETRE

    2010-10-01

    Full Text Available The wear of machine tools guides influences favorably to vibrations. As a result of guides wear, the initial trajectory of cutting tools motion will be modified, the generating dimensional accuracy discrepancies and deviations of geometrical shape of the work pieces. As it has already been known, the wear of mobile and rigid guides is determined by many parameters (pressure, velocity, friction length, lubrication, material. The choice of one or another analytic model and/or the experimental model of the wear is depending by the working conditions, assuming that the coupling material is known.The present work’s goal is to establish an analytic model of calculus showing the influence of the translation guides wear over the machining accuracy on machine-tools.

  19. Mississippi Curriculum Framework for Machine Tool Operation/Machine Shop (Program CIP: 48.0503--Machine Shop Assistant). Secondary Programs.

    Science.gov (United States)

    Mississippi Research and Curriculum Unit for Vocational and Technical Education, State College.

    This document, which reflects Mississippi's statutory requirement that instructional programs be based on core curricula and performance-based assessment, contains outlines of the instructional units required in local instructional management plans and daily lesson plans for machine tool operation/machine shop I and II. Presented first are a…

  20. 76 FR 27668 - ASC Machine Tools, Inc., Spokane Valley, WA; Notice of Negative Determination on Reconsideration

    Science.gov (United States)

    2011-05-12

    ... Employment and Training Administration ASC Machine Tools, Inc., Spokane Valley, WA; Notice of Negative... Regarding Application for Reconsideration for the workers and former workers of ASC Machine Tools, Inc... adjustment assistance for workers and former workers of ASC Machine Tools, Inc., Spokane Valley,...

  1. Vibration diagnostics of weak base embankments

    Institute of Scientific and Technical Information of China (English)

    Evgenij Ashpiz; Vladimir Kapustin; Svetlana Klepikova; Maxim Shirobokov

    2013-01-01

    In this paper the theoretical background was analyzed for vibration diagnostics method and experience in its application for weak base embankments. General schemes of survey and recommendations on hardware systems and further prospective development are outlined.

  2. Smart adaptronic hydrostatic guiding system for machine tool slides

    Science.gov (United States)

    Munzinger, C.; Weis, M.; Herder, S.

    2009-03-01

    Guiding systems figure amongst the central components in the flux of a machine tool. Their characteristics have a direct impact on machining accuracy. Hydrostatic guiding systems are preferably used when specific requirements are to be met with regards to accuracy, stiffness and damping. However, an active intervention in the guiding system of such conventional systems, i.e. to absorb geometrical guiding rail errors, has so far not been possible. Compared to modular, conventional systems, adaptronic systems offer considerable cost savings potentials thanks to their increased functional degree of integration [1].

  3. Simulation Process Analysis of Rubber Shock Absorber for Machine Tool

    Directory of Open Access Journals (Sweden)

    Chai Rong Xia

    2016-01-01

    Full Text Available The simulation on rubber shock absorber of machine tool was studied. The simple material model of rubber was obtained by through the finite element analysis software ABAQUS. The compression speed and the hardness of rubber material were considered to obtain the deformation law of rubber shock absorber. The location of fatigue were confirmed from the simulation results. The results shown that the fatigue position is distributed in the corner of shock absorber. The degree of deformation is increased with increasing of compress speed, and the hardness of rubber material is proportional to deformation.

  4. Dimensional Synthesis Design of Novel Parallel Machine Tool

    Institute of Scientific and Technical Information of China (English)

    汪劲松; 唐晓强; 段广洪; 尹文生

    2002-01-01

    This paper presents dimensional synthesis design theory for a novel planar 3-DOF (degrees of freedom) parallel machine tool. Closed-form solutions are developed for both the inverse and direct kinematics. The formulation of the dexterity and the definitions of the theoretical workspace and the valid workspace are used to analyze the effects of the design parameters on the dexterity and workspace. The analysis results are used to propose an approach to satisfy the platform motion requirement while realizing orientation capability, dexterity and valid workspace. A design example is given to illustrate the effectiveness of this approach.

  5. INVESTIGATION AND ASSESSMENT OF OCCUPATIONAL RISK ON THE METAL CUTTING MACHINE TOOL STAN

    Directory of Open Access Journals (Sweden)

    Jerzy Józwik

    2013-12-01

    Full Text Available The paper analyzes occupational risk at selected metal cutting machine tool stands (turning, milling, drilling and grinding stands and presents a set of recommendations formulated to minimize hazards at the above mentioned stands. The assessment is based on the analysis that allowed for selecting the best method of occupational risk assessment, measurements, observations, interviews and conclusions drawn from the obtained results. Occupational risk assessment forms were devised, what allowed for selecting appropriate action to increase the safety of selected machinery operators. The guidelines were assessed in terms of their practical implementation and expected utilitarian results.

  6. Study of on-machine error identification and compensation methods for micro machine tools

    Science.gov (United States)

    Wang, Shih-Ming; Yu, Han-Jen; Lee, Chun-Yi; Chiu, Hung-Sheng

    2016-08-01

    Micro machining plays an important role in the manufacturing of miniature products which are made of various materials with complex 3D shapes and tight machining tolerance. To further improve the accuracy of a micro machining process without increasing the manufacturing cost of a micro machine tool, an effective machining error measurement method and a software-based compensation method are essential. To avoid introducing additional errors caused by the re-installment of the workpiece, the measurement and compensation method should be on-machine conducted. In addition, because the contour of a miniature workpiece machined with a micro machining process is very tiny, the measurement method should be non-contact. By integrating the image re-constructive method, camera pixel correction, coordinate transformation, the error identification algorithm, and trajectory auto-correction method, a vision-based error measurement and compensation method that can on-machine inspect the micro machining errors and automatically generate an error-corrected numerical control (NC) program for error compensation was developed in this study. With the use of the Canny edge detection algorithm and camera pixel calibration, the edges of the contour of a machined workpiece were identified and used to re-construct the actual contour of the work piece. The actual contour was then mapped to the theoretical contour to identify the actual cutting points and compute the machining errors. With the use of a moving matching window and calculation of the similarity between the actual and theoretical contour, the errors between the actual cutting points and theoretical cutting points were calculated and used to correct the NC program. With the use of the error-corrected NC program, the accuracy of a micro machining process can be effectively improved. To prove the feasibility and effectiveness of the proposed methods, micro-milling experiments on a micro machine tool were conducted, and the results

  7. Step kinematic calibration of a 3-DOF planar parallel kinematic machine tool

    Institute of Scientific and Technical Information of China (English)

    CHANG Peng; WANG JinSong; LI TieMin; LIU XinJun; GUAN LiWen

    2008-01-01

    This paper presents a novel step kinematic calibration method for a 3 degree-of-freedom (DOF) planar parallel kinematic machine tool, based on the minimal linear combinations (MLCs) of error parameters. The method using mapping of linear combinations of parameters in error transfer multi-parameters coupling system changes the modeling, identification and error compensation of geometric pa-rameters in the general kinematic calibration into those of linear combinations of parameters. By using the four theorems of the MLCs, the sets of the MLCs that are respectively related to the relative precision and absolute precision are determined. All simple and feasible measurement methods in practice are given, and identifica-tion analysis of the set of the MLCs for each measurement is carried out. According to the identification analysis results, a step calibration including step measurement, step identification and step error compensation is determined by taking into ac-count both measurement costs and observability. The experiment shows that the proposed method has the following merits: (1) the parameter errors that cannot influence precision are completely avoided; (2) it reflects the mapping of linear combinations of parameters more accurately and enhances the precision of identi-fication; and (3) the method is robust, efficient and effective, so that the errors in position and orientation are kept at the same order of the measurement noise. Due to these merits, the present method is attractive for the 3-DOF planar parallel ki-nematic machine tool and can be also applied to other parallel kinematic machine tools with weakly nonlinear kinematics.

  8. Step kinematic calibration of a 3-DOF planar parallel kinematic machine tool

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper presents a novel step kinematic calibration method for a 3 degree-of-freedom(DOF) planar parallel kinematic machine tool,based on the minimal linear combinations(MLCs) of error parameters.The method using mapping of linear combinations of parameters in error transfer multi-parameters coupling system changes the modeling,identification and error compensation of geometric parameters in the general kinematic calibration into those of linear combinations of parameters.By using the four theorems of the MLCs,the sets of the MLCs that are respectively related to the relative precision and absolute precision are determined.All simple and feasible measurement methods in practice are given,and identification analysis of the set of the MLCs for each measurement is carried out.According to the identification analysis results,a step calibration including step measurement,step identification and step error compensation is determined by taking into account both measurement costs and observability.The experiment shows that the proposed method has the following merits:(1) the parameter errors that cannot influence precision are completely avoided;(2) it reflects the mapping of linear combinations of parameters more accurately and enhances the precision of identification;and(3) the method is robust,efficient and effective,so that the errors in position and orientation are kept at the same order of the measurement noise.Due to these merits,the present method is attractive for the 3-DOF planar parallel kinematic machine tool and can be also applied to other parallel kinematic machine tools with weakly nonlinear kinematics.

  9. Ultrasonic motors with polymer-based vibrators.

    Science.gov (United States)

    Wu, Jiang; Mizuno, Yosuke; Tabaru, Marie; Nakamura, Kentaro

    2015-12-01

    With their characteristics of low density and elastic moduli, polymers are promising materials for making ultrasonic motors (USMs) with high energy density. Although it has been believed for a long time that polymers are too lossy to be applied to high-amplitude vibrators, there are several new polymers that exhibit excellent vibration characteristics. First, we measure the damping coefficients of some functional polymers to explore the applicability of polymers as vibrators for USMs. Second, to investigate the vibration characteristics, we fabricate bimorph vibrators using several kinds of polymers that have low attenuation. Third, a bending mode USM is fabricated with a polymer rod and four piezoelectric plates bonded on the rod as a typical example of a USM. Through an experimental investigation of the motor performance, it was found that the polymer-based USMs exhibited higher rotation velocity than the aluminum-based USM under a light preload, although the maximum torque of the polymer-based USMs was smaller than the aluminum-based USM. Among the tested polymers, polyphenylenesulfide was a prospective material for USMs under light preloads because of the high amplitude and lightweight of polyphenylenesulfide.

  10. Virtual Sensor for Calibration of Thermal Models of Machine Tools

    Directory of Open Access Journals (Sweden)

    Alexander Dementjev

    2014-01-01

    strictly depends on the accuracy of these machines, but they are prone to deformation caused by their own heat. The deformation needs to be compensated in order to assure accurate production. So an adequate model of the high-dimensional thermal deformation process must be created and parameters of this model must be evaluated. Unfortunately, such parameters are often unknown and cannot be calculated a priori. Parameter identification during real experiments is not an option for these models because of its high engineering and machine time effort. The installation of additional sensors to measure these parameters directly is uneconomical. Instead, an effective calibration of thermal models can be reached by combining real and virtual measurements on a machine tool during its real operation, without additional sensors installation. In this paper, a new approach for thermal model calibration is presented. The expected results are very promising and can be recommended as an effective solution for this class of problems.

  11. A review of designing machine tool for leanness

    Indian Academy of Sciences (India)

    Anil Gupta; T K Kundra

    2012-04-01

    As an ideology, Leanness is not a new concept but still researchers strive for developing new methods to reduce almost all kinds of identified wastages at almost every stage and in every activity — right from design till delivery of final product to the end-customer. Newly developed manufacturing ideologies, paradigms and systems are always critically examined from the point of view of leanness. In other words, leanness is becoming an important evaluation tool to compare the recently developed/pioneered approaches. There has been a gradual evolution of the leanness over the years from the shop floor level of a manufacturing (automobile) organization to almost every operational and management aspect now. The Leanness has undergone and still is undergoing a process of continuous and never-ending evolution due to its inherently built dynamic concept of continuous improvement. Although in the literature a lot of work has been reported to the application of lean tools, principles, theories and methodologies to production systems, but a very few is evident in the area of Lean design process of a product and machine tool. For this reason an attempt is being made here to focus a significant proportion of this paper on evolutionary aspect of leanness from manufacturing to design stage. Also, this paper reviews the concepts and practices being followed till date by the industrialists, researchers and academicians in applying lean tools and techniques in the design of product and machine tools along with the methods to measure the lean improvements in the systems.

  12. Small machine tools for small workpieces final report of the DFG priority program 1476

    CERN Document Server

    Sanders, Adam

    2017-01-01

    This contributed volume presents the research results of the program “Small machine tools for small work pieces” (SPP 1476), funded by the German Research Society (DFG). The book contains the final report of the priority program, presenting novel approached for size-adapted, reconfigurable micro machine tools. The target audience primarily comprises research experts and practitioners in the field of micro machine tools, but the book may also be beneficial for graduate students.

  13. Actualities and Development of Heavy-Duty CNC Machine Tool Thermal Error Monitoring Technology

    Science.gov (United States)

    Zhou, Zu-De; Gui, Lin; Tan, Yue-Gang; Liu, Ming-Yao; Liu, Yi; Li, Rui-Ya

    2017-09-01

    Thermal error monitoring technology is the key technological support to solve the thermal error problem of heavy-duty CNC (computer numerical control) machine tools. Currently, there are many review literatures introducing the thermal error research of CNC machine tools, but those mainly focus on the thermal issues in small and medium-sized CNC machine tools and seldom introduce thermal error monitoring technologies. This paper gives an overview of the research on the thermal error of CNC machine tools and emphasizes the study of thermal error of the heavy-duty CNC machine tool in three areas. These areas are the causes of thermal error of heavy-duty CNC machine tool and the issues with the temperature monitoring technology and thermal deformation monitoring technology. A new optical measurement technology called the "fiber Bragg grating (FBG) distributed sensing technology" for heavy-duty CNC machine tools is introduced in detail. This technology forms an intelligent sensing and monitoring system for heavy-duty CNC machine tools. This paper fills in the blank of this kind of review articles to guide the development of this industry field and opens up new areas of research on the heavy-duty CNC machine tool thermal error.

  14. An Analysis Methodology for Stochastic Characteristic of Volumetric Error in Multiaxis CNC Machine Tool

    Directory of Open Access Journals (Sweden)

    Qiang Cheng

    2013-01-01

    Full Text Available Traditional approaches about error modeling and analysis of machine tool few consider the probability characteristics of the geometric error and volumetric error systematically. However, the individual geometric error measured at different points is variational and stochastic, and therefore the resultant volumetric error is aslo stochastic and uncertain. In order to address the stochastic characteristic of the volumetric error for multiaxis machine tool, a new probability analysis mathematical model of volumetric error is proposed in this paper. According to multibody system theory, a mean value analysis model for volumetric error is established with consideration of geometric errors. The probability characteristics of geometric errors are obtained by statistical analysis to the measured sample data. Based on probability statistics and stochastic process theory, the variance analysis model of volumetric error is established in matrix, which can avoid the complex mathematics operations during the direct differential. A four-axis horizontal machining center is selected as an illustration example. The analysis results can reveal the stochastic characteristic of volumetric error and are also helpful to make full use of the best workspace to reduce the random uncertainty of the volumetric error and improve the machining accuracy.

  15. The Use of Response Surface Methodology to Optimize Parameter Adjustments in CNC Machine Tools

    Directory of Open Access Journals (Sweden)

    Shao-Hsien Chen

    2014-01-01

    Full Text Available This paper mainly covers a research intended to improve the circular accuracy of CNC machine tools and the adjustment and analysis of the main controller parameters applied to improve accuracy. In this study, controller analysis software was used to detect the adjustment status of the servo parameters of the feed axis. According to the FANUC parameter manual, the parameter address, frequency, response measurements, and the one-fourth corner acceleration and deceleration measurements of the machine tools were adjusted. The experimental design (DOE was adopted in this study for taking circular measurements and engaging in the planning and selection of important parameter data. The Minitab R15 software was adopted to predict the experimental data analysis, while the seminormal probability map, Plato, and analysis of variance (ANOVA were adopted to determine the impacts of the significant parameter factors and the interactions among them. Additionally, based on the response surface map and contour plot, the optimal values were obtained. In addition, comparison and verification were conducted through the Taguchi method, regression analysis to improved machining accuracy and efficiency. The unadjusted error was 7.8 μm; through the regression analysis method, the error was 5.8 μm and through the Taguchi analysis method, the error was 6.4 μm.

  16. Vibration Based Sun Gear Damage Detection

    Science.gov (United States)

    Hood, Adrian; LaBerge, Kelsen; Lewicki, David; Pines, Darryll

    2013-01-01

    Seeded fault experiments were conducted on the planetary stage of an OH-58C helicopter transmission. Two vibration based methods are discussed that isolate the dynamics of the sun gear from that of the planet gears, bearings, input spiral bevel stage, and other components in and around the gearbox. Three damaged sun gears: two spalled and one cracked, serve as the focus of this current work. A non-sequential vibration separation algorithm was developed and the resulting signals analyzed. The second method uses only the time synchronously averaged data but takes advantage of the signal/source mapping required for vibration separation. Both algorithms were successful in identifying the spall damage. Sun gear damage was confirmed by the presence of sun mesh groups. The sun tooth crack condition was inconclusive.

  17. Vibrational Based Inspection Of A Steel Mast

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Rytter, A.

    1994-01-01

    The aim of this paper is to present the results from a research project concerning vibrational based inspection of a 20 meter high steel mast containing well defined damages. Introductory analyses dealing with among other things evaluation of potential damage indicators and determination...

  18. Real-Time Performance of Mechatronic PZT Module Using Active Vibration Feedback Control.

    Science.gov (United States)

    Aggogeri, Francesco; Borboni, Alberto; Merlo, Angelo; Pellegrini, Nicola; Ricatto, Raffaele

    2016-09-25

    This paper proposes an innovative mechatronic piezo-actuated module to control vibrations in modern machine tools. Vibrations represent one of the main issues that seriously compromise the quality of the workpiece. The active vibration control (AVC) device is composed of a host part integrated with sensors and actuators synchronized by a regulator; it is able to make a self-assessment and adjust to alterations in the environment. In particular, an innovative smart actuator has been designed and developed to satisfy machining requirements during active vibration control. This study presents the mechatronic model based on the kinematic and dynamic analysis of the AVC device. To ensure a real time performance, a H2-LQG controller has been developed and validated by simulations involving a machine tool, PZT actuator and controller models. The Hardware in the Loop (HIL) architecture is adopted to control and attenuate the vibrations. A set of experimental tests has been performed to validate the AVC module on a commercial machine tool. The feasibility of the real time vibration damping is demonstrated and the simulation accuracy is evaluated.

  19. PMC Control Design Principle and Program Implementation of Auxiliary Function M Commands in CNC Machine Tool Based on FANUC Oi Mate-MD System%基于FANUC Oi Mate-MD 系统的数控辅助功能M指令的PMC控制设计原理和程序实现

    Institute of Scientific and Technical Information of China (English)

    呼刚义; 杨新刚; 杨鹏

    2013-01-01

    数控机床辅助功能指令由CNC和PMC共同处理,但其具体运算处理过程国内还未见文献系统报道。用一具体实例对冷却液M指令的运行机制、PMC程序设计及加载、辅助功能M指令机床验证进行了详细阐述,有助于更好地使用、维护机床和利用系统提供的PMC梯形图来快速诊断故障,特别是对理解PMC程序、扩展开发机床控制功能提供了参考。%CNC machine tool auxiliary function commands are handled by CNC and PMC,but their concrete operation processes have not been reported in domestic literature system. Based on the specific examples,the operation mechanism of coolant M instruc-tion,the design and load of PMC program,the auxiliary function commands machine validation,were elaborated in detail. This will contribute to a better use and maintenance,and using PMC ladder diagram interface of NC system to diagnose fault quickly,especially it provides reference for understanding the PMC program,extending the development of machine control function.

  20. 75 FR 65516 - ASC Machine Tools, Inc., Spokane Valley, WA; Notice of Affirmative Determination Regarding...

    Science.gov (United States)

    2010-10-25

    ... Employment and Training Administration ASC Machine Tools, Inc., Spokane Valley, WA; Notice of Affirmative... apply for Trade Adjustment Assistance (TAA) applicable to workers and former workers of ASC Machine Tools, Inc., Spokane Valley, Washington (the subject firm). The Notice of negative determination...

  1. Static Stiffness Modeling of a Novel PKM-Machine Tool Structure

    Directory of Open Access Journals (Sweden)

    O. K. Akmaev

    2014-07-01

    Full Text Available This article presents a new configuration of a 3-dof machine tool with parallel kinematics. Elastic deformations of the machine tool have been modeled with finite elements, stiffness coefficients at characteristic points of the working area for different cutting forces have been calculated.

  2. THE CONFORMITY OF MACHINE TOOLS WITH RESPECT TO EUROPEAN SAFETY STANDARDS

    CERN Multimedia

    TIS/TE

    2001-01-01

    European regulations require that all motorized machine tools conform to the latest safety standards by the end of the year 2000. CERN must follow these regulations and has already modified most of its machine tools accordingly. However, there is still a small number of machine tools which have not yet been modified as required. These machines should not be used until they are brought up to the required safety standards, failing which the machines should be discarded. One can recognise which machine tools conform with the latest standards by the indication 'CS' on the identification plate of the machine, see foto below. In cases of doubt about the status of a machine tool you should contact K. Altherr/EST or C. Margaroli/TIS for advice.

  3. THE CONFORMITY OF MACHINE TOOLS WITH RESPECT TO EUROPEAN SAFETY STANDARDS

    CERN Multimedia

    TIS/TE

    2000-01-01

    European regulations require that all motorized machine tools conform to the latest safety standards by the end of the year 2000. CERN must follow these regulations and has already modified most of its machine tools accordingly. However, there is still a small number of machine tools which have not yet been modified as required. These machines should not be used until they are brought up to the required safety standards, failing which the machines should be discarded. One can recognise which machine tools conform with the latest standards by the indication 'CS' on the identification plate of the machine, see foto below. In cases of doubt about the status of a machine tool you should contact K. Altherr/EST or C. Margaroli/TIS for advice.

  4. The Electrical and Mechanical Alignment and Accuracy Detection of Numerial Control Machine Tool

    Institute of Scientific and Technical Information of China (English)

    XU Liang-xiong; ZHOU Xiang

    2012-01-01

    In the work of numerical control reformation of general machine tool, the installation and debugging of machine tool is a crucial part. For the C6132 machine tool, and make the use of electrical and mechanical alignment, parameter adjusting, numerical control lathe accuracy debugging and performance examination has been used to finish a series of tailing in the work of numerical control reformation of general machine tool. In this paper, the detailed process of electrical and mechanical alignment, parameter adjusting, numerical control lathe accuracy debugging and performance examination has been demonstrated, meanwhile, the specific operational approach of these work programs has been discussed. Therefore, the present results provides essential reference and approach for the numerical control reformation of general machine tool.

  5. 基于遗传算法优化Elman神经网络的机床热误差建模∗%Thermal Error Modeling for Machine Tool Based on Genetic Algorithm Optimization Elman Neural Network

    Institute of Scientific and Technical Information of China (English)

    黄玉春; 田建平; 杨海栗; 胡勇; 张良栋

    2015-01-01

    In order to improve the prediction accuracy of CNC machine thermal error model, a vertical ma-chining center was taken as a research object. The temperature measuring points of machine are optimized by using a combined method of fuzzy clustering and grey comprehensive relationship degree. The tempera-ture measuring points were reduced from 8 to 3. The prediction model of spindle thermal drift error was es-tablished based on genetic algorithm optimization Elman neural network. The predictive effect of GA-Elman neural network model and the common Elman neural network models were compared through the example. Compared with the prediction model built by the ordinary Elman neural network, the results show that the Elman neural network has higher fitting accuracy, smaller residual error and better generalization capacity on spindle axial thermal drift error.%为了提高数控机床热误差模型的预测精度,以某型号立式加工中心为实验对象,采用模糊聚类与灰色综合关联度相结合的方法对机床测温点进行优化,将测温点从8个减少到3个。利用遗传算法( GA)优化的Elman神经网络建立了主轴热漂移误差预测模型,通过实例比较了 GA-Elman神经网络模型与普通Elman 神经网络模型的预测效果。结果表明,与普通Elman神经网络所建的预测模型相比,GA-Elman神经网络模型对主轴轴向热漂移误差的预测精度较高,残差较小,网络的泛化能力较好。

  6. Sensorless compensation system for thermal deformations of ball screws in machine tools drives

    Science.gov (United States)

    Kowal, Michał

    2016-12-01

    The article presents constructional, technological and operational issues associated with the compensation of thermal deformations of ball screw drives. Further, it demonstrates the analysis of a new sensorless compensation method relying on coordinated computation of data fed directly from the drive and the control system in combination with the information pertaining to the operational history of the servo drive, retrieved with the use of an artificial neural networks (ANN)-based learning system. Preliminary ANN-based models, developed to simulate energy dissipation resulting from the friction in the screw-cap assembly and convection of heat are expounded upon, as are the processes of data selection and ANN learning. In conclusion, the article presents the results of simulation studies and preliminary experimental evidence confirming the applicability of the proposed method, efficiently compensating for the thermal elongation of the ball screw in machine tool drives.

  7. Factors discriminating inventory management performance: An exploratory study of Indian machine tool SMEs

    Directory of Open Access Journals (Sweden)

    Rajeev Narayana Pillai

    2014-06-01

    Full Text Available Purpose: There are many kinds of methods to evaluate the inventory management and economic performance of small and medium enterprises, but they still have some distinct shortcomings. In order to achieve a better evaluation result, we put forward a new model based on the evidences from developing country like India.Approach: This survey study, mainly based on the evidences from machine tool SMEs in India uses statistical methods to avoid the drawbacks of qualitative techniques.Findings: Through empirical data, it is established that ‘technology’ is not the only concern, but other factors related to human resource, economic, organizational and behavioral aspects of SMEs are also vital in improving their IM performance.Originality: This study combines the role of factors such as managerial, technological, economical and contingency together for the first time in the context of SMEs.

  8. User's manual for tooth contact analysis of face-milled spiral bevel gears with given machine-tool settings

    Science.gov (United States)

    Litvin, Faydor L.; Zhang, YI; Chen, Jui-Sheng

    1991-01-01

    Research was performed to develop a computer program that will: (1) simulate the meshing and bearing contact for face milled spiral beval gears with given machine tool settings; and (2) to obtain the output, some of the data is required for hydrodynamic analysis. It is assumed that the machine tool settings and the blank data will be taken from the Gleason summaries. The theoretical aspects of the program are based on 'Local Synthesis and Tooth Contact Analysis of Face Mill Milled Spiral Bevel Gears'. The difference between the computer programs developed herein and the other one is as follows: (1) the mean contact point of tooth surfaces for gears with given machine tool settings must be determined iteratively, while parameters (H and V) are changed (H represents displacement along the pinion axis, V represents the gear displacement that is perpendicular to the plane drawn through the axes of the pinion and the gear of their initial positions), this means that when V differs from zero, the axis of the pionion and the gear are crossed but not intersected; (2) in addition to the regular output data (transmission errors and bearing contact), the new computer program provides information about the contacting force for each contact point and the sliding and the so-called rolling velocity. The following topics are covered: (1) instructions for the users as to how to insert the input data; (2) explanations regarding the output data; (3) numerical example; and (4) listing of the program.

  9. Kinematic Analysis of a Serial - Parallel Machine Tool: the VERNE machine

    CERN Document Server

    Kanaan, Daniel; Chablat, Damien; 10.1016/j.mechmachtheory.2008.03.002

    2008-01-01

    The paper derives the inverse and the forward kinematic equations of a serial - parallel 5-axis machine tool: the VERNE machine. This machine is composed of a three-degree-of-freedom (DOF) parallel module and a two-DOF serial tilting table. The parallel module consists of a moving platform that is connected to a fixed base by three non-identical legs. These legs are connected in a way that the combined effects of the three legs lead to an over-constrained mechanism with complex motion. This motion is defined as a simultaneous combination of rotation and translation. In this paper we propose symbolical methods that able to calculate all kinematic solutions and identify the acceptable one by adding analytical constraint on the disposition of legs of the parallel module.

  10. Calculation and analysis for stiffness of the thrust aerostatic bearing of ultra-precision machine tools

    Science.gov (United States)

    Lu, Lihua; Zhao, Ziqiang; Liang, Yingchun; Zhang, Longjiang

    2010-10-01

    The single point diamond turning (SPDT) lathe of vertical flying cutting milling style is one important ultra-precision machining method for Large-aperture optics. To realize ultra-precision machining with SPDT technology, the turning spindle of the machine tools should be with higher stiffness and stability. In this paper, based on finite element method (FEM), an iterative procedure is proposed and implemented to solve the fluid dynamic model and structure model for simulation the couple of air pressure and structure flexibility. Simulation results show that pressure in the air gap makes the plate deform and this deformation produced by the pressure adversely modifies the pressure distribution. Experimental results indicate that the method can predict the aerostatic spindle stiffness accurately, the prediction error is about 2.04%. These results show a relevant influence of the structural flexibility of the bearing on its static performance.

  11. Precision Measurement of Cylinder Surface Profile on an Ultra-Precision Machine Tool

    Science.gov (United States)

    Lee, J. C.; Noh, Y. J.; Arai, Y.; Gao, W.; Park, C. H.

    2009-01-01

    This paper describes the measurement of the surface straightness profile of a cylinder workpiece on an ultra-precision machine tool which has a T-base design with a spindle, an X-slide and a Z-slide. The movement range of the X-slide is 220 mm and that of the Z-slide is 150 mm, which have roller bearings in common. Two capacitive sensors are employed to scan a cylinder workpiece mounted on the spindle along the Z-axis. The straightness error motion of the Z-slide is measured to be approximately 100 nm by the reversal method. The straightness profile of the cylinder workpiece is evaluated to be approximately 400 nm by separation of the motion error, simultaneously.

  12. Bend-insensitive fiber based vibration sensor

    Science.gov (United States)

    Xu, Yanping; Lu, Ping; Baset, Farhana; Bhardwaj, Vedula Ravi; Bao, Xiaoyi

    2014-05-01

    We report two novel fiber-optic vibration sensors based on standard telecom bend-insensitive fiber (BIF). A tapered BIF forming a fiber Mach-Zehnder interferometer could measure continuous and damped vibration from 1 Hz up to 500 kHz. An enclosed microcantilever is fabricated inside the BIF by chemical etching and fusion spliced with a readout singlemode fiber that exhibits a frequency range from 5 Hz to 10 kHz with high signal-to-noise ratio (SNR) up to 68 dB. The unique double cladding structure of the BIF ensures both sensors with advantages of compactness, high resistance to the external disturbance and stronger mechanical strength.

  13. Motion and Virtual Cutting Simulation System for a Five-Axis Virtual Machine Tool

    Directory of Open Access Journals (Sweden)

    Rong-Shean Lee

    2011-09-01

    Full Text Available Since five-axis machine tools are very costly and their use requires a high level of knowledge and expertise, a virtual machine tool must be used to simulate five-axis machine tool operation. Configuration code or a mechanism topology matrix must be used to describe a machine tool, and can be used as the framework for design of a virtual machine tool system. The first step is to isolate the basic motions of each element of a virtual machine tool and then establish their coordinate systems. The establishment of a node tree allows coordinate transformation matrices for virtual motion components to be derived, which are then used to simulate movements. The simulation of virtual cutting must take into consideration both accuracy and efficiency. While either a GPU or CPU can be used to perform calculations, there are currently restrictions on GPU memory use which results in relatively lower accuracy. In contrast, a CPU can perform calculations using an adaptive octree with voxels and multithreading to yield sufficient accuracy and efficiency. A five-axis virtual machine tool motion and virtual cutting simulation system was written in C/C++ with OpenGL and OpenMP, and can perform real-time cutting simulations.

  14. Solving the warehouse stacker routing problem of machine tool manufacturers based on adaptive genetic algorithm%基于改进自适应遗传算法求解机床制造企业立体仓库堆垛机路径优化问题

    Institute of Scientific and Technical Information of China (English)

    周耿烈; 冯无恙; 胡赤兵

    2012-01-01

    Using machine tool manufacturing industry as the background, based on automated warehouse storing machine parts, the automated warehouse stacker path is analyzed emphatically. Through the improved a-daptive genetic algorithm, genetic operators can be calculated at any time to adapt,overcome premature convergence of traditional genetic algorithms. Method to set the serial number through the use of cargo space in the location in the warehouse, picking stacker established mathematical model, using the improved genetic algorithm to improve the initial path, the optimal solution, and using Matlab Genetic Algorithms Box to simulate, experiment results show that this method converges faster and can gel global optimal solution, the stacking machine path planning is more quick and efficient.%以机床制造业为背景,以存放机床零部件的自动化立体仓库为基础,重点分析自动化立体仓库堆垛机的路径分析.通过对遗传算法进行自适应改进,算出能够随时适应的遗传算子,克服了传统遗传算法的早熟收敛问题.通过运用序号法设定各货位在立体仓库中的位置,建立堆垛机拣选作业的数学模型,运用改进自适应遗传算法对初始路径进行改进,得出最优解,并运用Matlab遗传算法工具箱对此进行仿真,实验结果表明,此方法收敛速度快,可以获得全局最优解,其堆垛机路径规划更加快速和有效.

  15. Inverse kinematics analysis and numerical control experiment for PRS-XY style hybrid machining tool

    Institute of Scientific and Technical Information of China (English)

    JIA Dongyong; ZHANG Jianmin; NIU Zhigang; SUN Hongchang

    2007-01-01

    This paper analyzed the inverse kinematics for the new Parallel rotate slider-X Y axes(PRS-XY)style hybrid machining tool and educed the five axes linkage inverse kinematics transform formula on the basis of the coordinates of the X,Y,Z,A and B virtual axes.The program for the PRS-XY style hybrid machining tool in accordance with the program manner for the common numerical control(NC)machine tool was made.The results of the experiments prove that the inverse kinematics transform formula is correct.

  16. Experimental study on bearing preload optimum of machine tool spindle

    Science.gov (United States)

    Xu, Tao; Xu, Guanghua; Zhang, Qin; Hua, Cheng; Zhang, Hu; Jiang, Kuosheng

    2012-05-01

    An experimental study is conducted to investigate the possibility and the effect of temperature rise and vibration level of bearing by adjusting axial preloads and radial loads in spindle bearing test rig. The shaft of the test rig is driven by a motorized high speed spindle at the range of 0~20000 rpm. The axial preloads and radial loads on bearings are controlled by using hydraulic pressure which can be adjusted automatically. Temperature rise and radial vibration of test bearings are measured by thermocouples and Polytec portable laser vibrometer PDV100. Experiment shows that the temperature rise of bearings is nonlinear varying with the increase of radial loads, but temperature rise almost increases linearly with the increase of axial preload and rotating speed. In this paper, an alternate axial preload is used for bearings. When the rotating speed passes through the critical speed of the shaft, axial preload of bearings will have a remarkable effect. The low preload could reduce bearing vibration and temperature rise for bearings as well. At the others speed, the high preload could improve the vibration performance of high speed spindle and the bearing temperature was lower than that of the constant pressure preload spindle.

  17. Error Modeling and Sensitivity Analysis of a Five-Axis Machine Tool

    Directory of Open Access Journals (Sweden)

    Wenjie Tian

    2014-01-01

    Full Text Available Geometric error modeling and its sensitivity analysis are carried out in this paper, which is helpful for precision design of machine tools. Screw theory and rigid body kinematics are used to establish the error model of an RRTTT-type five-axis machine tool, which enables the source errors affecting the compensable and uncompensable pose accuracy of the machine tool to be explicitly separated, thereby providing designers and/or field engineers with an informative guideline for the accuracy improvement by suitable measures, that is, component tolerancing in design, manufacturing, and assembly processes, and error compensation. The sensitivity analysis method is proposed, and the sensitivities of compensable and uncompensable pose accuracies are analyzed. The analysis results will be used for the precision design of the machine tool.

  18. DYNAMICS ANALYSIS OF SPECIAL STRUCTURE OF MILLING-HEAD MACHINE TOOL

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The milling-bead machine tool is a sophisticated and high-quality machine tool of which the spindle system is made up of special multi-element structure. Two special mechanical configurations make the cutting performance of the machine tool decline. One is the milling head spindle supported on two sets of complex bearings. The mechanical dynamic rigidity of milling head structure is researched on designed digital prototype with finite element analysis(FEA) and modal synthesis analysis (MSA) for identifying the weak structures. The other is the ram structure hanging on milling head. The structure is researched to get dynamic performance on cutting at different ram extending positions. The analysis results on spindle and ram are used to improve the mechanical configurations and structure in design. The machine tool is built up with modified structure and gets better dynamic rigidity than it was before.

  19. EMBEDDED COMPUTER BASED ACTIVE VIBRATION CONTROL SYSTEM FOR VIBRATION REDUCTION OF FLEXIBLE STRUCTURES

    Directory of Open Access Journals (Sweden)

    Venkata Ratnam Tatavolu

    2013-01-01

    Full Text Available Research on Active Vibration Control System (AVCS is being carried out to reduce structural vibrations caused by unwanted vibrations in many application areas such as in space, aircraft structures, satellites, automobiles and civil structures (bridges, particularly at low frequencies. The unwanted vibration may cause damage to the structure or degradation to the structure’s performance. The AVCS comprises physical plant, a sensor to detect the source vibration, a DSP based electronic controller using an actuator connected to the structure generates a counter force that is appropriately out of phase but equal in amplitude to the source vibration. As a result two equal and opposite forces cancel each other by the principle of super position and structure stops vibrating. The main objective of this research work is to develop an embedded computer based real time AVCS for reducing low frequency tonal vibration response of a vibrating flexible cantilever beam by automatic modification of the vibrating beam’s structural response and to verify the performance of the developed system experimentally. The developed AVCS is a generic design platform that can be applied for designing adaptive feed forward AVC and feedback AVC. This study presents the vibration control methodology adapted for reducing tonal vibration generated by a sine generator connected to the primary source actuator attached to one end of the cantilever beam. The secondary actuator is attached to the beam on the other end through the AVCS to reduce primary vibration by destructive interference with the original response of the system, caused by the primary source of vibration. Adaptive feed forward Active Vibration Control (AVC technique is used with Filtered-X Least Mean Square (FxLMS algorithm using FIR digital filter. A cantilever beam was considered as plant and embedded computer based AVCS was tested and evaluated using an experimental setup. The experimental results are

  20. The Fuzzy Cluster Analysis in Identification of Key Temperatures in Machine Tool

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The thermal-induced error is a very important sour ce of machining errors of machine tools. To compensate the thermal-induced machin ing errors, a relationship model between the thermal field and deformations was needed. The relationship can be deduced by virtual of FEM (Finite Element Method ), ANN (Artificial Neural Network) or MRA (Multiple Regression Analysis). MR A is on the basis of a total understanding of the temperature distribution of th e machine tool. Although the more the temperatures measu...

  1. THEORETICAL CLARIFICATIONS REGARDING THE CONCEPT OF WORKING CAPACITY OF WOOD-WORKING MACHINE-TOOLS

    Directory of Open Access Journals (Sweden)

    Gavril BUDĂU

    2014-09-01

    Full Text Available Due to persisting confusions between the concepts “labor productivity” and “working capacity” of a machine-tool, equipment or production line, the authors considered it necessary to define and explain these terms. Starting by defining the notions “working cycle” and “functioning cycle”, the paper details: the theoretical, technological and real working capacity and also the term “working time norm” for wood-working machine-tools.

  2. Performance investigation of capillary tubes for machine tool coolers retrofitted with HFC-407C refrigerant

    Science.gov (United States)

    Wang, Fujen; Chang, Tongbou; Chiang, Weiming; Lee, Haochung

    2012-09-01

    The machine tool coolers are the best managers of coolant temperature in avoiding the deviation of spindle centerline for machine tools. However, the machine coolers are facing the compressed schedule to phase out the HCFC (hydro-chloro-floro-carbon) refrigerant and little attention has been paid to comparative study on sizing capillary tube for retrofitted HFC (hydro-floro-carbon) refrigerant. In this paper, the adiabatic flow in capillary tube is analyzed and modeled for retrofitting of HFC-407C refrigerant in a machine tool cooler system. A computer code including determining the length of sub-cooled flow region and the two phase region of capillary tube is developed. Comparative study of HCFC-22 and HFC-407C in a capillary tube is derived and conducted to simplify the traditional trial-and-error method of predicting the length of capillary tubes. Besides, experimental investigation is carried out by field tests to verify the simulation model and cooling performance of the machine tool cooler system. The results from the experiments reveal that the numerical model provides an effective approach to determine the performance data of capillary tube specific for retrofitting a HFC-407C machine tool cooler. The developed machine tool cooler system is not only directly compatible with new HFC-407C refrigerant, but can also perform a cost-effective temperature control specific for industrial machines.

  3. A Comparative Study of Teacher Education Institutions and Machine Tool Manufacturers to Determine Course Content for a Machine Tool Maintenance Course in the Woodworking Area.

    Science.gov (United States)

    Polette, Douglas Lee

    To determine what type of maintenance training the prospective industrial arts teacher should receive in the woodworking area and how this information should be taught, a research instrument was constructed using information obtained from a review of relevant literature. Specific data on machine tool maintenance was gathered by the use of two…

  4. 数控机床产业强势增长%Robust growth of NC machine tool industry

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ The machine tool industry is an industry which provides production equipment for the equipment manufacturing industry, and the machine tool is the parent machine for equipment manufacturing, playing a key part in the industry.The equipment manufacturing industry, for example, the automobile industry, uses more than 60% of its fixed asset investment in the purchase of machine tools.The numerical control (NC)machine tool, as a mainstream product of the machine tool sector, has become a key piece of equipment for achieving modernisation of equipment manufacturing.It is the realistic requirement to speed up development of NC machine production for the development of China's equipment manufacturing industry.

  5. Active Vibration Isolation System for Sub-microultra-precision Turning Machine

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Now vibration isolation of ultra-precision machine tool is usually achieved through air-springs systems. As far as HCM-I sub-micro turning machine developed by HIT, an active vibration isolation system that consists of air-springs and electro-magnetic actuators was presented. The primary function of air-springs is to support the turning machine and to isolate the high-frequency vibration. The electro-magnetic actuators controlled by fuzzy-neural networks isolate the low-frequency vibration. The experiment indicates that active vibration isolation system isolates base-vibration effectively in all the frequency range. So the vibration of the machine bed is controlled under 10-6g and the surface roughness is improved.

  6. Kinematic and dynamic analysis and simulation on parallel kinematics machine tool%并联运动机床运动学和动力学分析与仿真

    Institute of Scientific and Technical Information of China (English)

    张毅; 牟思惠; 陈怀军

    2011-01-01

    以4-XPXUYYUX型并联运动机床为例,采用影响系数法建立了运动学分析的数学模型,利用Lagrange方程求解出动力学模型,为其它理论分析奠定基础。同时以虚拟样机软件ADAMS为工具,建立了并联机床的仿真模型,并对并联机床进行了动力学分析,获得了并联运动机床的动态特性,从而完善并优化了并联运动机床的系统设计。%The parallel kinematics machine tool is based on the space of mechanism.It can achieve space complex motion,meet requirements of processing of multi-degree freedom,and can process complex parts.Because the design process of a parallel kinematics machine tool is quite complicated,there are limitations of the traditional design methods using experience and static researches.It is necessary to explore the related design theories and study the dynamic characteristics of the parallel kinematics machine tool.This study takes a 4-XPXUYYUX parallel kinematics machine tool as an example,develops the mathematical model of kinematics analysis by the coefficient method.The dynamic model is solved using Lagrange equation,which can provide the basis for other theoretical analysis.We develop a simulation model of parallel kinematics machine tool by the virtual prototype software-ADAMS,and analyze the dynamic of parallel kinematics machine tool.The dynamic characteristics of parallel kinematics machine tool are acquired.The system design of parallel kinematics machine tool is improved and optimized.

  7. Nonlinearity for a parallel kinematic machine tool and its application to interpolation accuracy analysis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    [1]Carlo,I.,Direct Position Analysis of The Stewart Platform Mechanism,Mech.Mach.Theory,1990,25(6): 611-621.[2]Fitchter,E.F.,A Stewart platform based manipulator general theory and practical construction,Inter.Journal of Robtics Research,1986,(2): 157-182.[3]Raghavan,M.,The Stewart platform of general geometry has 40 configurations,ASME J.Mechanical Design,1993,115(2): 277-281.[4]Wampler,C.W.,Forward displacement analysis of general six-in-parallel SPS (Stewart) platform manipulators using SOMA Coordinates,Mech.Mach.Theory,1995,31(3): 331-337.[5]Wen,F.A.,Liang,C.G.,Displacement analysis of the 6-6 stewart platform mechanisms,Mech.Mach.Theory,1994,29(4): 547-557.[6]Liang,C.G.,Rong,H.,The forward displacement solution to a Stewart platform type maniputator,China Journal of Mechanical Engineering,1991,27(2): 26-30.[7]Huang,Z.,Spatial Mechanisms,Beijing: China Machine Press,1991.[8]Liu,K.et al.,The singularities and dynamics of a stewart platform manipulator,J.of Intelligent and Robotic Systems,1993,8: 287-308.[9]Bates,D.M.,Watts,D.G.,Relative curvature measures of nonlinearity,Journal of the Royal Statistical Society,1980(B42): 1-25.[10]Huang Tian,Wang Jinsong,Whitehouse,D.J.,Theory and methodology for kinematic design of Gough-Stewart platforms,Science in China,Series E,1999,42(4): 425-436.[11]Wang,Z.H.,Wang,J.S.,Yang,X.D.,Wei,Y.M.,Interpolation scheme and simulation study on its accuracy for a Stewart platform based CNC machine Tool VAMTIY,China Mechanical Engineering,1999,10(10): 1121-1123.[12]Wang Zhonghua,Wang Jinsong,Study on interpolation and its error distribution in workspace for a Stewart platform based CNC machine tool,in Proceedings of International Conference on Advanced Manufacturing Systems and Manufacturing Automation (AMSMA'2000),19th-2st,June,2000,Guangzhou,China.

  8. Vibrational Based Inspection of Civil Engineering Structures

    DEFF Research Database (Denmark)

    Rytter, Anders

    at the University of Aalborg from 1988 to 1991. Secondly, a research project, In-Field Vibration Based Inspection of Civil Engineering Structures, which has been performed as a pilot project by the Consulting Engineers Rambøll, Hannemann and Højlund in cooperation with the department of Building Technology......The thesis has been written in relation to two different research projects. Firstly, an offshore test programme, Integrated Experimental/Numerical Analysis of the Dynamic behavior of offshore structures, which was performed at the department of Building Technology and Structural Engineering...... and Structural Engineering at the University of Aalborg since the beginning of 1992. Both projects have been supported by the Danish Technical Research Council. Further, the first mentioned project was supported by the Danish Energy Agency. Their financial support is gratefully acknowledged....

  9. Stability analysis of machine tool spindle under uncertainty

    Directory of Open Access Journals (Sweden)

    Wei Dou

    2016-05-01

    Full Text Available Chatter is a harmful machining vibration that occurs between the workpiece and the cutting tool, usually resulting in irregular flaw streaks on the finished surface and severe tool wear. Stability lobe diagrams could predict chatter by providing graphical representations of the stable combinations of the axial depth of the cut and spindle speed. In this article, the analytical model of a spindle system is constructed, including a Timoshenko beam rotating shaft model and double sets of angular contact ball bearings with 5 degrees of freedom. Then, the stability lobe diagram of the model is developed according to its dynamic properties. The Monte Carlo method is applied to analyse the bearing preload influence on the system stability with uncertainty taken into account.

  10. Active vibration isolation platform on base of magnetorheological elastomers

    Science.gov (United States)

    Mikhailov, Valery P.; Bazinenkov, Alexey M.

    2017-06-01

    The article describes the active vibration isolation platform on base of magnetorheological (MR) elastomers. An active damper based on the MR elastomers can be used as an actuator of micro- or nanopositioning for a vibroinsulated object. The MR elastomers give such advantages for active control of vibration as large range of displacements (up to 1 mm), more efficient absorption of the vibration energy, possibility of active control of amplitude-frequency characteristics and positioning with millisecond response speed and nanometer running accuracy. The article presents the results of experimental studies of the most important active damper parameters. Those are starting current, transient time for stepping, transmission coefficient of the vibration displacement amplitude.

  11. Statistical quality control through overall vibration analysis

    Science.gov (United States)

    Carnero, M. a. Carmen; González-Palma, Rafael; Almorza, David; Mayorga, Pedro; López-Escobar, Carlos

    2010-05-01

    The present study introduces the concept of statistical quality control in automotive wheel bearings manufacturing processes. Defects on products under analysis can have a direct influence on passengers' safety and comfort. At present, the use of vibration analysis on machine tools for quality control purposes is not very extensive in manufacturing facilities. Noise and vibration are common quality problems in bearings. These failure modes likely occur under certain operating conditions and do not require high vibration amplitudes but relate to certain vibration frequencies. The vibration frequencies are affected by the type of surface problems (chattering) of ball races that are generated through grinding processes. The purpose of this paper is to identify grinding process variables that affect the quality of bearings by using statistical principles in the field of machine tools. In addition, an evaluation of the quality results of the finished parts under different combinations of process variables is assessed. This paper intends to establish the foundations to predict the quality of the products through the analysis of self-induced vibrations during the contact between the grinding wheel and the parts. To achieve this goal, the overall self-induced vibration readings under different combinations of process variables are analysed using statistical tools. The analysis of data and design of experiments follows a classical approach, considering all potential interactions between variables. The analysis of data is conducted through analysis of variance (ANOVA) for data sets that meet normality and homoscedasticity criteria. This paper utilizes different statistical tools to support the conclusions such as chi squared, Shapiro-Wilks, symmetry, Kurtosis, Cochran, Hartlett, and Hartley and Krushal-Wallis. The analysis presented is the starting point to extend the use of predictive techniques (vibration analysis) for quality control. This paper demonstrates the existence

  12. Applying CBR to machine tool product configuration design oriented to customer requirements

    Science.gov (United States)

    Wang, Pengjia; Gong, Yadong; Xie, Hualong; Liu, Yongxian; Nee, Andrew Yehching

    2017-01-01

    Product customization is a trend in the current market-oriented manufacturing environment. However, deduction from customer requirements to design results and evaluation of design alternatives are still heavily reliant on the designer's experience and knowledge. To solve the problem of fuzziness and uncertainty of customer requirements in product configuration, an analysis method based on the grey rough model is presented. The customer requirements can be converted into technical characteristics effectively. In addition, an optimization decision model for product planning is established to help the enterprises select the key technical characteristics under the constraints of cost and time to serve the customer to maximal satisfaction. A new case retrieval approach that combines the self-organizing map and fuzzy similarity priority ratio method is proposed in case-based design. The self-organizing map can reduce the retrieval range and increase the retrieval efficiency, and the fuzzy similarity priority ratio method can evaluate the similarity of cases comprehensively. To ensure that the final case has the best overall performance, an evaluation method of similar cases based on grey correlation analysis is proposed to evaluate similar cases to select the most suitable case. Furthermore, a computer-aided system is developed using MATLAB GUI to assist the product configuration design. The actual example and result on an ETC series machine tool product show that the proposed method is effective, rapid and accurate in the process of product configuration. The proposed methodology provides a detailed instruction for the product configuration design oriented to customer requirements.

  13. Applying CBR to machine tool product configuration design oriented to customer requirements

    Science.gov (United States)

    Wang, Pengjia; Gong, Yadong; Xie, Hualong; Liu, Yongxian; Nee, Andrew Yehching

    2016-03-01

    Product customization is a trend in the current market-oriented manufacturing environment. However, deduction from customer requirements to design results and evaluation of design alternatives are still heavily reliant on the designer's experience and knowledge. To solve the problem of fuzziness and uncertainty of customer requirements in product configuration, an analysis method based on the grey rough model is presented. The customer requirements can be converted into technical characteristics effectively. In addition, an optimization decision model for product planning is established to help the enterprises select the key technical characteristics under the constraints of cost and time to serve the customer to maximal satisfaction. A new case retrieval approach that combines the self-organizing map and fuzzy similarity priority ratio method is proposed in case-based design. The self-organizing map can reduce the retrieval range and increase the retrieval efficiency, and the fuzzy similarity priority ratio method can evaluate the similarity of cases comprehensively. To ensure that the final case has the best overall performance, an evaluation method of similar cases based on grey correlation analysis is proposed to evaluate similar cases to select the most suitable case. Furthermore, a computer-aided system is developed using MATLAB GUI to assist the product configuration design. The actual example and result on an ETC series machine tool product show that the proposed method is effective, rapid and accurate in the process of product configuration. The proposed methodology provides a detailed instruction for the product configuration design oriented to customer requirements.

  14. Force transmissibility and vibration power flow behaviour of inerter-based vibration isolators

    Science.gov (United States)

    Yang, Jian

    2016-09-01

    This paper investigates the dynamics and performance of inerter-based vibration isolators. Force / displacement transmissibility and vibration power flow are obtained to evaluate the isolation performance. Both force and motion excitations are considered. It is demonstrated that the use of inerters can enhance vibration isolation performance by enlarging the frequency band of effective vibration isolation. It is found that adding inerters can introduce anti-resonances in the frequency-response curves and in the curves of the force and displacement transmissibility such that vibration transmission can be suppressed at interested excitation frequencies. It is found that the introduction of inerters enhances inertial coupling and thus have a large influence on the dynamic behaviour at high frequencies. It is shown that force and displacement transmissibility increases with the excitation frequency and tends to an asymptotic value as the excitation frequency increases. In the high-frequency range, it was shown that adding inerters can result in a lower level of input power. These findings provide a better understanding of the effects of introducing inerters to vibration isolation and demonstrate the performance benefits of inerter-based vibration isolators.

  15. VIBRATION ANALYSIS OF TURBINE BASED ON FLUID-STRUCTURE COUPLING

    Institute of Scientific and Technical Information of China (English)

    LIU Demin; LIU Xiaobing

    2008-01-01

    The vibration of a Francis turbine is analyzed with the additional quality matrix method based on fluid-structure coupling (FSC). Firstly, the vibration frequency and mode of blade and runner in air and water are calculated. Secondly, the influences to runner frequency domain by large flow, small flow and design flow working conditions are compared. Finally the influences to runner modes by centrifugal forces under three rotating speeds of 400 r/min, 500 r/min and 600 r/min are compared. The centrifugal force and small flow working condition have greatly influence on the vibration of small runner. With the increase of centrifugal force, the vibration frequency of the runner is sharply increased. Some order frequencies are even close to the runner natural frequency in the air. Because the low frequency vibration will severely damage the stability of the turbine, low frequency vibration of units should be avoided as soon as possible.

  16. A Real-Time Tool Positioning Sensor for Machine-Tools

    Science.gov (United States)

    Ruiz, Antonio Ramon Jimenez; Rosas, Jorge Guevara; Granja, Fernando Seco; Honorato, Jose Carlos Prieto; Taboada, Jose Juan Esteve; Serrano, Vicente Mico; Jimenez, Teresa Molina

    2009-01-01

    In machining, natural oscillations, and elastic, gravitational or temperature deformations, are still a problem to guarantee the quality of fabricated parts. In this paper we present an optical measurement system designed to track and localize in 3D a reference retro-reflector close to the machine-tool's drill. The complete system and its components are described in detail. Several tests, some static (including impacts and rotations) and others dynamic (by executing linear and circular trajectories), were performed on two different machine tools. It has been integrated, for the first time, a laser tracking system into the position control loop of a machine-tool. Results indicate that oscillations and deformations close to the tool can be estimated with micrometric resolution and a bandwidth from 0 to more than 100 Hz. Therefore this sensor opens the possibility for on-line compensation of oscillations and deformations. PMID:22408472

  17. A real-time tool positioning sensor for machine-tools.

    Science.gov (United States)

    Ruiz, Antonio Ramon Jimenez; Rosas, Jorge Guevara; Granja, Fernando Seco; Honorato, Jose Carlos Prieto; Taboada, Jose Juan Esteve; Serrano, Vicente Mico; Jimenez, Teresa Molina

    2009-01-01

    In machining, natural oscillations, and elastic, gravitational or temperature deformations, are still a problem to guarantee the quality of fabricated parts. In this paper we present an optical measurement system designed to track and localize in 3D a reference retro-reflector close to the machine-tool's drill. The complete system and its components are described in detail. Several tests, some static (including impacts and rotations) and others dynamic (by executing linear and circular trajectories), were performed on two different machine tools. It has been integrated, for the first time, a laser tracking system into the position control loop of a machine-tool. Results indicate that oscillations and deformations close to the tool can be estimated with micrometric resolution and a bandwidth from 0 to more than 100 Hz. Therefore this sensor opens the possibility for on-line compensation of oscillations and deformations.

  18. IDENTIFICATION AND MONITORING OF NOISE SOURCES OF CNC MACHINE TOOLS BY ACOUSTIC HOLOGRAPHY METHODS

    Directory of Open Access Journals (Sweden)

    Jerzy Józwik

    2016-06-01

    Full Text Available The paper presents the analysis of sound field emitted by selected CNC machine tools. The identification of noise sources and level was measured by acoustic holography for the 3-axis DMC 635eco machine tool and the 5-axis vertical machining centre DMU 65 monoBlock. The acoustic holography method allows precise identification and measurement of noise sources at different bandwidths of frequency. Detection of noise sources in tested objects allows diagnosis of their technical condition, as well as choice of effective means of noise reduction, which is highly significant from the perspective of minimising noise at the CNC machine operator workstation. Test results were presented as acoustic maps in various frequency ranges. Noise sources of the machine tool itself were identified, as well as the range of noise influence and the most frequent places of reflections and their span. The results of measurements were presented in figures and diagrams.

  19. Kinematic simulation of a parallel NC machine tool in the manufacturing process

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jian-min; FAN Yu; JIA Dong-yun; ZOU Qiu-ling; WU Ying

    2006-01-01

    Aimed at enhancing the research status of parallel machine tools,this paper introduces the structure of a 6-SPS parallel machine tool and explains the application significance of the kinematic simulation of the manufacturing process.The simulation software was developed in Microsoft Visual C++6.0 using OpenGL API functions.The data flows are presented.Finally, a simulation application of odd leaf hyperboloid is performed before the manufacturing process; the kinematic simulation demonstrates the rationale of trace planning and the feasibility of manufacturing instruction.

  20. An Universal Modeling Method for Enhancing the Volumetric Accuracy of CNC Machine Tools

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Volumetric error modeling method is an important te ch nique for enhancement the accuracy of CNC machine tools by error compensation. I n the research field, the main question is how to find an universal kinematics m odeling method for different kinds of NC machine tools. Multi-body system theor y is always used to solve the dynamics problem of complex physical system. But t ill now, the error factors that always exist in practice system is still not con sidered. In this paper, the accuracy kinematics of MB...

  1. Dynamic parameters’ identification for the feeding system of computer numerical control machine tools stimulated by G-code

    Directory of Open Access Journals (Sweden)

    Guangsheng Chen

    2015-08-01

    Full Text Available This study proposed a dynamic parameters’ identification method for the feeding system of computer numerical control machine tools based on internal sensor. A simplified control model and linear identification model of the feeding system were established, in which the input and output signals are from sensors embedded in computer numerical control machine tools, and the dynamic parameters of the feeding system, including the equivalent inertia, equivalent damping, worktable damping, and the overall stiffness of the mechanical system, were solved by the least square method. Using the high-order Taylor expansion, the nonlinear Stribeck friction model was linearized and the parameters of the Stribeck friction model were obtained by the same way. To verify the validity and effectiveness of the identification method, identification experiments, circular motion testing, and simulations were conducted. The results obtained were stable and suggested that inertia and damping identification experiments converged fast. Stiffness identification experiments showed some deviation from simulation due to the influences of geometric error and nonlinear of stiffness. However, the identification results were still of reference significance and the method is convenient, effective, and suited for industrial condition.

  2. Design of Pinion Machine Tool-settings for Spiral Bevel Gears by Controlling Contact Path and Transmission Errors

    Institute of Scientific and Technical Information of China (English)

    Cao Xuemei; Fang Zongde; Xu Hao; Su Jinzhan

    2008-01-01

    This paper proposes a new approach to design pinion machine tool-settings for spiral bevel gears by controlling contact path and transmis- sion errors. It is based on the satisfaction of contact condition of three given control points on the tooth surface. The three meshing points are controlled to be on a predesigned straight contact path that meets the pre-designed parabolic function of transmission errors. Designed separately, the magnitude of transmission errors and the orientation of the contact path are subjected to precise control. In addition, in order to meet the manufacturing requirements, we suggest to modify the values of blank offset, one of the pinion machine tool-settings, and redesign pinion ma- chine tool-settings to ensure that the magnitude and the geometry of transmission errors should not be influenced apart from minor effects on the predesigned straight contact path. The proposed approach together with its ideas has been proven by a numerical example and the manufacturing practice of a pair of spiral bevel gears.

  3. Optimizing the way kinematical feed chains with great distance between slides are chosen for CNC machine tools

    Science.gov (United States)

    Lucian, P.; Gheorghe, S.

    2017-08-01

    This paper presents a new method, based on FRISCO formula, for optimizing the choice of the best control system for kinematical feed chains with great distance between slides used in computer numerical controlled machine tools. Such machines are usually, but not limited to, used for machining large and complex parts (mostly in the aviation industry) or complex casting molds. For such machine tools the kinematic feed chains are arranged in a dual-parallel drive structure that allows the mobile element to be moved by the two kinematical branches and their related control systems. Such an arrangement allows for high speed and high rigidity (a critical requirement for precision machining) during the machining process. A significant issue for such an arrangement it’s the ability of the two parallel control systems to follow the same trajectory accurately in order to address this issue it is necessary to achieve synchronous motion control for the two kinematical branches ensuring that the correct perpendicular position it’s kept by the mobile element during its motion on the two slides.

  4. Adaptive control of mechatronic machine-tool equipment

    Directory of Open Access Journals (Sweden)

    R.G. Kudoyarov

    2015-09-01

    Full Text Available In this paper the method for designing a functional structure of mechatronic modules based on the developed classification of functional subsystems and the proposed turning machine modular structure is presented.

  5. Vibration-based SHM System: Application to Wind Turbine Blades

    DEFF Research Database (Denmark)

    Tcherniak, D.; Mølgaard, Lasse Lohilahti

    2015-01-01

    This study presents an vibration-based system designed for structural health monitoring of wind turbine blades. Mechanical energy is introduced by means of an electromechanical actuator mounted inside the blade. The actuator's plunger periodically hits the blade structure; the induced vibrations...... propagate along the blade and are measured by an array of accelerometers. Unsupervised learning is applied to the data: the vibration patterns corresponding to the undamaged blade are used to create a statistical model of the reference state. During the detection stage, the current vibration pattern...... is compared with the reference state, and the novelties can be associated with damage. The vibration pattern is described by the covariance matrix between the accelerometer signals. The mid-range frequencies are used: this range is above the frequencies excited by blade-wind interaction, thus ensuring a good...

  6. Axial vibration analysis of nanocones based on nonlocal elasticity theory

    Institute of Scientific and Technical Information of China (English)

    Shu-Qi Guo; Shao-Pu Yang

    2012-01-01

    Carbon nanocones have quite fascinating electronic and structural properties,whose axial vibration is seldom investigated in previous studies.In this paper,based on a nonlocal elasticity theory,a nonuniform rod model is applied to investigate the small-scale effect and the nonuniform effect on axial vibration of nanocones.Using the modified Wentzel-Brillouin-Kramers (WBK) method,an asymptotic solution is obtained for the axial vibration of general nonuniform nanorods.Then,using similar procedure,the axial vibration of nanocones is analyzed for nonuniform parameters,mode number and nonlocal parameters.Explicit expressions are derived for mode frequencies of clamped-clamped and clamped-free boundary conditions.It is found that axial vibration frequencies are highly overestimated by the classical rod model because of ignorance of the effect of small length scale.

  7. Machine Tool Layout: Outlining a Basic Shape on Flat Steel. Fordson Bilingual Demonstration Project.

    Science.gov (United States)

    Ochsner, Alan

    This vocational instructional module on outlining a basic shape on flat steel is one of eight such modules designed to assist recently arrived Arab students, limited in English proficiency (LEP), in critical instructional areas in a comprehensive high school. Goal stated for this module is for the student enrolled in a machine tool course to…

  8. Mathematics for the Workplace. Applications from Machine Tool Technology (Michelin Tire Corporation). A Teacher's Guide.

    Science.gov (United States)

    Wallace, Johnny M.; Stewart, Grover

    This module presents a real-world context in which mathematics skills (geometry and trigonometry) are used as part of a daily routine. The context is the machine tool technology field, and the module aims to help students develop the ability to analyze diagrams in order to make mathematical computations. The modules, which features applications…

  9. Technology and Jobs: Computer-Aided Design. Numerical-Control Machine-Tool Operators. Office Automation.

    Science.gov (United States)

    Stanton, Michael; And Others

    1985-01-01

    Three reports on the effects of high technology on the nature of work include (1) Stanton on applications and implications of computer-aided design for engineers, drafters, and architects; (2) Nardone on the outlook and training of numerical-control machine tool operators; and (3) Austin and Drake on the future of clerical occupations in automated…

  10. Remediation, General Education, and Technical Mathematics. Educational Resources for the Machine Tool Industry.

    Science.gov (United States)

    Texas State Technical Coll. System, Waco.

    This document contains descriptions of adult education courses in remediation, general education, and technical mathematics. They are part of a program developed by the Machine Tool Advanced Skills Technology Educational Resources (MASTER) program to help workers become competent in the skills needed to be productive workers in the machine tools…

  11. MACHINE TOOL OPERATOR--GENERAL, ENTRY, SUGGESTED GUIDE FOR A TRAINING COURSE.

    Science.gov (United States)

    RONEY, MAURICE W.; AND OTHERS

    THE PURPOSE OF THIS CURRICULUM GUIDE IS TO ASSIST THE ADMINISTRATOR AND INSTRUCTOR IN PLANNING AND DEVELOPING MANPOWER DEVELOPMENT AND TRAINING PROGRAMS TO PREPARE MACHINE TOOL OPERATORS FOR ENTRY-LEVEL POSITIONS. THE COURSE OUTLINE PROVIDES UNITS IN -- (1) ORIENTATION, (2) BENCH WORK, (3) SHOP MATHEMATICS, (4) BLUEPRINT READING AND SKETCHING, (5)…

  12. Adaption of commercial off the shelf modules for reconfigurable machine tool design

    CSIR Research Space (South Africa)

    Mpofu, K

    2008-01-01

    Full Text Available of design of machine tools to achieve flexibility through reconfigurability is discussed. Highlights of the implication of this method and it’s repercussions to basic modules, alternate modules and additional modules are analysed. The role of the computer...

  13. Manufacturing process applications team (MATEAM). [technology transfer in the areas of machine tools and robots

    Science.gov (United States)

    1979-01-01

    The transfer of NASA technology to the industrial sector is reported. Presentations to the machine tool and robot industries and direct technology transfers of the Adams Manipulator arm, a-c motor control, and the bolt tension monitor are discussed. A listing of proposed RTOP programs with strong potential is included. A detailed description of the rotor technology available to industry is given.

  14. Note: Vibration suppression using tunable vibration absorber based on stiffness variable magneto-rheological gel

    Science.gov (United States)

    Shin, Beom-Cheol; Yoon, Jung-Hwan; Kim, Young-Keun; Kim, Kyung-Soo

    2015-10-01

    This paper proposes a novel adaptive tunable vibration absorber (TVA) based on a smart material the magnetorheological gel (MRG) to achieve a wide range of tonal vibration suppression on the primary system to protect any connected sensitive device. The vibration suppression performance of the MRG TVA was analyzed by conducting a modal test of the primary system under different magnetic fields. The experiment verified that the proposed MRG TVA can be controlled to produce 379% of stiffness change or 115% of tuning frequency under just 200 mT magnetic field. The proposed MRG TVA was found to possess a wider tuning frequency range than the TVA based on other smart material such as magnetorheological elastomer.

  15. Dry Machining Tool Design via Chlorine Ion Implantation

    Institute of Scientific and Technical Information of China (English)

    Tatsuhiko Aizawa; Atsushi Mitsuo; Shigeo Yamamoto; Shinji Muraishi; Taro Sumitomo

    2004-01-01

    Dry machining has become a key issue to significantly reduce the wastes of used lubricants and cleaning agents and to improve the environmental consciousness for medical and food applications of special tooling. Since the tools and metallic works are in direct contact in dry, severe adhesive wear and oxidation are thought to occur even at the presence of hard protective coatings. Self-lubrication mechanism with use of lubricous oxide films is found to be effective for dry machining. Through the chlorine ion implantation to tools, titanium base oxides are in-situ formed on the tool surface.This oxide deforms elasto-plastically so that both friction coefficient and wear volume are reduced even in the high-speed cutting.

  16. Dry Machining Tool Design via Chlorine Ion Implantation

    Institute of Scientific and Technical Information of China (English)

    TatsuhikoAizawa; AtsushiMitsuo; ShigeoYamamoto; ShinjiMuraishi; TaroSumitomo

    2004-01-01

    Dry machining has become a key issue to significantly reduce the wastes of used lubricants and cleaning agents and to improve the environmental consciousness for medical and food applications of special tooling. Since the tools and metallic works are in direct contact in dry, severe adhesive wear and oxidation are thought to occur even at the presence of hard protective coatings. Self-lubrication mechanism with use of lubricous oxide films is found to be effective for dry machining. Through the chlorine ion implantation to tools, titanium base oxides are in-situ formed on the tool surface. This oxide deforms elasto-plastically so that both friction coefficient and wear volume are reduced even in the high-speed cutting.

  17. Laser-error-correction control unit for machine tools

    Energy Technology Data Exchange (ETDEWEB)

    Burleson, R.R.

    1978-05-23

    An ultraprecision machining capability is needed for the laser fusion program. For this work, a precision air-bearing spindle has been mounted horizontally on a modified vertical column of a Moore Number 3 measuring machine base located in a development laboratory at the Oak Ridge Y-12 Plant. An open-loop control system previously installed on this machine was inadequate to meet the upcoming requirements since accuracy is limited to 0.5 ..mu..m by the errors in the machine's gears and leadscrew. A new controller was needed that could monitor the actual position of the machine and perform real-time error correction on the programmed tool path. It was necessary that this project: (1) attain an optimum tradeoff between hardware and software; (2) use a modular design for easy maintenance; (3) use a standard NC tape service; (4) drive the x and y axes with a positioning resolution of 5.08 nm and a feedback resolution of 10 nm; (5) drive the x and y axis motors at a velocity of 0.05 cm/sec in the contouring mode and 0.18 cm/sec in the positioning mode; (6) eliminate the possibility of tape-reader errors; and (7) allow editing of the part description data. The work that was done to develop and install the new machine controller is described.

  18. Prospects for chaos control of machine tool chatter

    Energy Technology Data Exchange (ETDEWEB)

    Hively, L.M.; Protopopescu, V.A.; Clapp, N.E.; Daw, C.S.

    1998-06-01

    The authors analyze the nonlinear tool-part dynamics during turning of stainless steel in the nonchatter and chatter regimes, toward the ultimate objective of chatter control. Their previous work analyzed tool acceleration in three dimensions at four spindle speeds. In the present work, the authors analyze the machining power and obtain nonlinear measures of this power. They also calculate the cycle-to-cycle energy for the turning process. Return maps for power cycle times do not reveal fixed points or (un)stable manifolds. Energy return maps do display stable and unstable directions (manifolds) to and from an unstable period-1 orbit, which is the dominant periodicity. Both nonchatter and chatter dynamics have the unusual feature of arriving at the unstable period-1 fixed point and departing from that fixed point of the energy return map in a single step. This unusual feature makes chaos maintenance, based on the well-known Ott-Grebogi-Yorke scheme, a very difficult option for chatter suppression. Alternative control schemes, such as synchronization of the tool-part motion to prerecorded nonchatter dynamics or dynamically damping the period-1 motion, are briefly discussed.

  19. Synthesis of Vibration Waves Based on Wavelet Technology

    Directory of Open Access Journals (Sweden)

    L.H. Zou

    2012-01-01

    Full Text Available A novel method to generate time series of vibration waves is proposed in the paper. Considering the frequency band energy as the criterion, synthesis formulas for fluctuating wind pressure and earthquake ground motion are developed in terms of Daubechies wavelet and Harr wavelet respectively. The wavelet reconstruction method is applicable to both stationary and non-stationary process simulation. Theoretically, for non-stationary (such as seismic process synthesis, it has a better non-stationarity in time-frequency domain than the traditional trigonometric series. Influence of wavelet delamination number and wavelet function type is also analyzed. Numerical results show that the synthesis of vibration waves based on wavelet reconstruction method contains main components of vibration, and can reflect the main properties of practical vibrations.

  20. Active vibration control based on piezoelectric smart composite

    Science.gov (United States)

    Gao, Le; Lu, Qingqing; Fei, Fan; Liu, Liwu; Liu, Yanju; Leng, Jinsong

    2013-12-01

    An aircraft’s vertical fin may experience dramatic buffet loads in high angle of attack flight conditions, and these buffet loads would cause huge vibration and dynamic stress on the vertical fin structure. To reduce the dynamic vibration of the vertical fin structure, macro fiber composite (MFC) actuators were used in this paper. The drive moment equations and sensing voltage equations of the MFC actuators were developed. Finite element analysis models based on three kinds of models of simplified vertical fin structures with surface-bonded MFC actuators were established in ABAQUS. The equivalent damping ratio of the structure was employed in finite element analysis, in order to measure the effectiveness of vibration control. Further, an open-loop test for the active vibration control system of the vertical fin with MFC actuators was designed and developed. The experimental results validated the effectiveness of the MFC actuators as well as the developed methodology.

  1. Acoustic vibration sensor based on nonadiabatic tapered fibers.

    Science.gov (United States)

    Xu, Ben; Li, Yi; Sun, Miao; Zhang, Zhen-Wei; Dong, Xin-Yong; Zhang, Zai-Xuan; Jin, Shang-Zhong

    2012-11-15

    A simple and low-cost vibration sensor based on single-mode nonadiabatic fiber tapers is proposed and demonstrated. The environmental vibrations can be detected by demodulating the transmission loss of the nonadiabatic fiber taper. Theoretical simulations show that the transmission loss is related to the microbending of the fiber taper induced by vibrations. Unlike interferometric sensors, this vibration sensor does not need any feedback loop to control the quadrature point to obtain a stable performance. In addition, it has no requirement for the coherence of the light source and is insensitive to temperature changes. Experimental results show that this sensing system has a wide frequency response range from a few hertz to tens of kilohertz with the maximal signal to noise ratio up to 73 dB.

  2. A Real-Time Tool Positioning Sensor for Machine-Tools

    Directory of Open Access Journals (Sweden)

    Vicente Mico Serrano

    2009-09-01

    Full Text Available In machining, natural oscillations, and elastic, gravitational or temperature deformations, are still a problem to guarantee the quality of fabricated parts. In this paper we present an optical measurement system designed to track and localize in 3D a reference retro-reflector close to the machine-tool’s drill. The complete system and its components are described in detail. Several tests, some static (including impacts and rotations and others dynamic (by executing linear and circular trajectories, were performed on two different machine tools. It has been integrated, for the first time, a laser tracking system into the position control loop of a machine-tool. Results indicate that oscillations and deformations close to the tool can be estimated with micrometric resolution and a bandwidth from 0 to more than 100 Hz. Therefore this sensor opens the possibility for on-line compensation of oscillations and deformations.

  3. Five-Axis Machine Tool Condition Monitoring Using dSPACE Real-Time System

    Science.gov (United States)

    Sztendel, S.; Pislaru, C.; Longstaff, A. P.; Fletcher, S.; Myers, A.

    2012-05-01

    This paper presents the design, development and SIMULINK implementation of the lumped parameter model of C-axis drive from GEISS five-axis CNC machine tool. The simulated results compare well with the experimental data measured from the actual machine. Also the paper describes the steps for data acquisition using ControlDesk and hardware-in-the-loop implementation of the drive models in dSPACE real-time system. The main components of the HIL system are: the drive model simulation and input - output (I/O) modules for receiving the real controller outputs. The paper explains how the experimental data obtained from the data acquisition process using dSPACE real-time system can be used for the development of machine tool diagnosis and prognosis systems that facilitate the improvement of maintenance activities.

  4. Position-independent geometric error identification and global sensitivity analysis for the rotary axes of five-axis machine tools

    Science.gov (United States)

    Guo, Shijie; Jiang, Gedong; Zhang, Dongsheng; Mei, Xuesong

    2017-04-01

    Position-independent geometric errors (PIGEs) are the fundamental errors of a five-axis machine tool. In this paper, to identify ten PIGEs peculiar to the rotary axes of five-axis machine tools with a tilting head, the mathematic model of the ten PIGEs is deduced and four measuring patterns are proposed. The measuring patterns and identifying method are validated on a five-axis machine tool with a tilting head, and the ten PIGEs of the machine tool are obtained. The sensitivities of the four adjustable PIGEs of the machine tool in different measuring patterns are analyzed by the Morris global sensitivity analysis method and the modifying method, and the procedure of the four adjustable PIGEs of the machine tool is given accordingly. Experimental results show that after and before modifying the four adjustable PIGEs, the average compensate rate reached 52.7%. It is proved that the proposed measuring, identifying, analyzing and modifying method are effective for error measurement and precision improvement of the five-axis machine tool.

  5. Bayesian Reliability Modeling and Assessment Solution for NC Machine Tools under Small-sample Data

    Institute of Scientific and Technical Information of China (English)

    YANG Zhaojun; KAN Yingnan; CHEN Fei; XU Binbin; CHEN Chuanhai; YANG Chuangui

    2015-01-01

    Although Markov chain Monte Carlo(MCMC) algorithms are accurate, many factors may cause instability when they are utilized in reliability analysis; such instability makes these algorithms unsuitable for widespread engineering applications. Thus, a reliability modeling and assessment solution aimed at small-sample data of numerical control(NC) machine tools is proposed on the basis of Bayes theories. An expert-judgment process of fusing multi-source prior information is developed to obtain the Weibull parameters’ prior distributions and reduce the subjective bias of usual expert-judgment methods. The grid approximation method is applied to two-parameter Weibull distribution to derive the formulas for the parameters’ posterior distributions and solve the calculation difficulty of high-dimensional integration. The method is then applied to the real data of a type of NC machine tool to implement a reliability assessment and obtain the mean time between failures(MTBF). The relative error of the proposed method is 5.8020×10-4 compared with the MTBF obtained by the MCMC algorithm. This result indicates that the proposed method is as accurate as MCMC. The newly developed solution for reliability modeling and assessment of NC machine tools under small-sample data is easy, practical, and highly suitable for widespread application in the engineering field; in addition, the solution does not reduce accuracy.

  6. Thermal Error Modeling of a Machine Tool Using Data Mining Scheme

    Science.gov (United States)

    Wang, Kun-Chieh; Tseng, Pai-Chang

    In this paper the knowledge discovery technique is used to build an effective and transparent mathematic thermal error model for machine tools. Our proposed thermal error modeling methodology (called KRL) integrates the schemes of K-means theory (KM), rough-set theory (RS), and linear regression model (LR). First, to explore the machine tool's thermal behavior, an integrated system is designed to simultaneously measure the temperature ascents at selected characteristic points and the thermal deformations at spindle nose under suitable real machining conditions. Second, the obtained data are classified by the KM method, further reduced by the RS scheme, and a linear thermal error model is established by the LR technique. To evaluate the performance of our proposed model, an adaptive neural fuzzy inference system (ANFIS) thermal error model is introduced for comparison. Finally, a verification experiment is carried out and results reveal that the proposed KRL model is effective in predicting thermal behavior in machine tools. Our proposed KRL model is transparent, easily understood by users, and can be easily programmed or modified for different machining conditions.

  7. Influence of export control policy on the competitiveness of machine tool producing organizations

    Science.gov (United States)

    Ahrstrom, Jeffrey D.

    The possible influence of export control policies on producers of export controlled machine tools is examined in this quantitative study. International market competitiveness theories hold that market controlling policies such as export control regulations may influence an organization's ability to compete (Burris, 2010). Differences in domestic application of export control policy on machine tool exports may impose throttling effects on the competitiveness of participating firms (Freedenberg, 2010). Commodity shipments from Japan, Germany, and the United States to the Russian market will be examined using descriptive statistics; gravity modeling of these specific markets provides a foundation for comparison to actual shipment data; and industry participant responses to a user developed survey will provide additional data for analysis using a Kruskal-Wallis one-way analysis of variance. There is scarce academic research data on the topic of export control effects within the machine tool industry. Research results may be of interest to industry leadership in market participation decisions, advocacy arguments, and strategic planning. Industry advocates and export policy decision makers could find data of interest in supporting positions for or against modifications of export control policies.

  8. Thermal Characteristics Analysis of the Ram System of TK6920 Heavy-duty CNC Floor-type Boring and Milling Machine Tool Based on ANSYS%基于ANSYS的TK6920数控铣镗床滑枕系统热特性分析

    Institute of Scientific and Technical Information of China (English)

    韩江; 昂金凤; 夏链; 丰云

    2012-01-01

    以TK6920数控铣镗床滑枕系统为研究对象,研究了其热态特性及其对机床性能的影响.首先运用三维软件对其进行三维实体建模,计算系统的热源以及相应的边界条件;其次运用有限元软件仿真计算滑枕系统的稳态温度场分布以及热平衡时间;最后根据分析结果提出改善滑枕系统热态特性的措施.%The effect of thermal properties on performance was determined for the ram system of a TK6920 heavy-duty CNC floor-type boring and milling machine tool. First, the three-dimensional model of the ram system was established with 3Dsoftware. And calculated the thermal source, confirmed the boundary conditions. After that, the constant temperature field distribution and thermal equilibrium time of the ram system was simulated and calculated with the finite element analysis software. At last, according to the result, some measures to optimize the thermal characters of the ram system were put forward.

  9. Bridge Condition Assessment based on Vibration Responses of Passenger Vehicle

    Science.gov (United States)

    Miyamoto, Ayaho; Yabe, Akito

    2011-07-01

    In this paper, we propose a new method of assessing the condition of existing short- and medium-span reinforced/prestressed concrete bridges based on vibration monitoring data obtained from a public bus. This paper not only describes details of a prototype monitoring system that uses information technology and sensors capable of providing more accurate knowledge of bridge performance than conventional ways but also shows a few specific examples of bridge condition assessment based on vehicle vibrations measured by using an in-service public bus equipped with vibration measurement instrumentation. This paper also describes a sensitivity analysis of deteriorating bridges based on simulation of the acceleration response of buses conducted by the "substructure method" employing a finite element model to verify the above bridge performance results. The main conclusions obtained in this study can be summarized as follows: (1) Because the vibration responses of passenger vehicles, such as buses, have a good linear relationship with the vibration responses of the target bridges, the proposed system can be used as a practical monitoring system for bridge condition assessment. (2) The results of sensitivity analysis performed by the substructure method show that bus vibration responses are useful for evaluating target bridge performance. (3) The proposed method was applied to a network of real bridges in a local area to evaluate its effectiveness. The results indicate that the proposed method can be used to prioritize the repair/strengthening works of existing bridges based on various vibration information in order to help bridge administrators establish rational maintenance strategies.

  10. Design of vibration sensor based on fiber Bragg grating

    Science.gov (United States)

    Zhang, Zhengyi; Liu, Chuntong

    2017-06-01

    Fiber grating is a kind of new type of fiber optic light source device which has been rapidly changing in the refractive index of the core in recent years. Especially, it can realize the high precision of the external parameters by means of the special structure design and the encapsulation technology [1, 2]. In this paper, a fiber grating vibration sensor which is suitable for vibration monitoring in key areas is designed based on the technical background of vibration monitoring system. The sensor uses a single beam structure and pastes the fiber Bragg grating (FBG) to measure the vibration wavelength on the surface. When the vibration is simply harmonic vibration, the Bragg reflection wavelength will change periodically, and the periodic variation of the wavelength curve can be measured by the fiber grating demodulator, then the correctness of the experimental results is verified. In this paper, through the analysis of the data measured by the demodulator, the MATLAB software is used to verify the data, and the different frequency domains, the modes, and the phase frequency curves are obtained. The measurement range is 0 Hz-100 Hz, and the natural frequency is 90.6 Hz.

  11. A Fiber Bragg Grating Sensing Based Triaxial Vibration Sensor.

    Science.gov (United States)

    Li, Tianliang; Tan, Yuegang; Liu, Yi; Qu, Yongzhi; Liu, Mingyao; Zhou, Zude

    2015-09-18

    A fiber Bragg grating (FBG) sensing based triaxial vibration sensor has been presented in this paper. The optical fiber is directly employed as elastomer, and the triaxial vibration of a measured body can be obtained by two pairs of FBGs. A model of a triaxial vibration sensor as well as decoupling principles of triaxial vibration and experimental analyses are proposed. Experimental results show that: sensitivities of 86.9 pm/g, 971.8 pm/g and 154.7 pm/g for each orthogonal sensitive direction with linearity are separately 3.64%, 1.50% and 3.01%. The flat frequency ranges reside in 20-200 Hz, 3-20 Hz and 4-50 Hz, respectively; in addition, the resonant frequencies are separately 700 Hz, 40 Hz and 110 Hz in the x/y/z direction. When the sensor is excited in a single direction vibration, the outputs of sensor in the other two directions are consistent with the outputs in the non-working state. Therefore, it is effectively demonstrated that it can be used for three-dimensional vibration measurement.

  12. 机床的数字控制(下)%The numerical control of Machine tool

    Institute of Scientific and Technical Information of China (English)

    樊留群; 朱志浩; 张曙; 黄云鹰

    2016-01-01

    论述了机床数控系统的现状和发展趋势,分析了开放式数控系统的体系结构,指出了STEP-NC是下一代数控系统发展方向之一。数控系统通过不断提高插补精度和采用数字总线伺服来提高加工精度的同时,采用信息物理深度融合(CPS)技术,提高数控系统的人机交互、网络化和智能化水平。现在数控系统不仅是生产加工设备的控制系统,也成了智能工厂不可缺少的信息节点。%It reviews the current situation and development trend of CNC machine tools, analyzes the architecture of open CNC system, presents that the STEP-NC is one of the next generation of numerical control system devel-opment. It introduces the method of constantly improving the interpolation precision and machining accuracy by using the digital servo bus, illustrates the process for improving machine tool performance of human-machine in-teraction, networking and intelligent CNC system based on cyber physical depth fusion (CPS) technology. Now CNC is not only a controller of machine, but also an indispensable information node of smart factory.

  13. 可重构机床新型接口设计∗%Interface Design of Reconfigurable Machine Tool

    Institute of Scientific and Technical Information of China (English)

    李一全; 姜倩; 许金凯; 梁冲

    2015-01-01

    Based on the concept, characteristics about micro reconfigurable manufacturing system, two kinds of new mechanical module interface was studied and designed;Two kinds of new module interfaces that re-spectively used in the machine tool was designed, in order to realize the function change about turning and milling; According to the stress distribution of the prototype in the actual processing. Done the statics and dynamics analysis for the two main structure of the machine tool with interfaces. After these work for mod-ule interface have laid a certain foundation for the application in reconfigurable micro-processing system.%该设计以可重构车铣微加工系统为背景,根据可重构车铣微加工系统的概念及特点,对机械模块接口进行了深入研究和创新设计;基于可重构车铣微加工机床的重构要求,设计出了两种分别应用于机床中主轴模块和工作台模块的新型接口,接口可以实现机床车铣功能快速互换;并根据实际加工中该机床的受力情况,分别对接口接入到机床主运动系统和工作台时,进行了静力学分析和动力学分析,对接口的性能进行了评价,为以后模块接口在可重构微加工系统中的应用提供了基础。

  14. SIMULATION OF VIBRATION STRESS RELIEF AFTER WELDING BASED ON FEM

    Institute of Scientific and Technical Information of China (English)

    X.C.Zhao; Y.D.Zhang; H.W.Zhang; Q.Wu

    2008-01-01

    A finite element model is developed for the simulation of vibration stress relief (VSR) after welding.For the nonresonant vibration,the reduction in stress strongly depends on the amplitude of vibration.For the resonant vibration,the vibration frequency is the key for stress relief.The vibration frequency should be close to the structure natural frequency for the desired vibration mode.Only small vibration amplitude is required,which will be amplified during vibration.Vibration time does not have a major impact on vibration stress relief.When the amplitude of vibration stress relief is large,the treatment will be more effective.

  15. [Study on Enhancing Characteristic Vibration of the Molecular Vibration Spectrum for BDE-15 Based on Solvent Effect].

    Science.gov (United States)

    Jiang, Long; Meng, Chong; Li, Yu

    2015-12-01

    the similar change trend with Raman vibrational intensities. The spectra information of BDE-153, BDE-154, BDE-209 were used to authenticate the application on PBDEs of the analysis method above for BDE-15, obtaining the solvent effect index values on vibrational intensities on BDE-153, BDE-154, BDE-209 of alcohols, acetonitrile, dimethyl sulfoxide, nitrobenzene are all greater than 6 or 5, which indicate the enhancing vibrational intensities method can be used to identification research on PBDEs based on molecule vibrational spectra further.

  16. A Comparative Study of Three Vibration Based Damage Assessment Techniques

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Rytter, A.

    Three different vibration based damage assessment techniques have been compared. One of the techniques uses the ratios between changes in experimentally and theoretically estimated natural frequencies, respectively, to locate a damage. The second technique relies on updating of an FEM based...

  17. An electromagnetic inerter-based vibration suppression device

    Science.gov (United States)

    Gonzalez-Buelga, A.; Clare, L. R.; Neild, S. A.; Jiang, J. Z.; Inman, D. J.

    2015-05-01

    This paper describes how an inerter-based device for structural vibration suppression can be realized using an electromagnetic transducer such as a linear motor. When the motor shaft moves, a difference of voltage is generated across the transducer coil. The voltage difference is proportional to the relative velocity between its two terminals. The electromagnetic transducer will exert a force proportional to current following the Lorentz principle if the circuit is closed around the transducer coil. If an electronic circuit consisting of a capacitor, an inductance and a resistance with the appropriate configuration is connected, the resulting force reflected back into the mechanical domain is equivalent to that achieved by a mechanical inerter-based device. The proposed configuration is easy to implement and very versatile, provided a high quality conversion system with negligible losses. With the use of electromagnetic devices, a new generation of vibration absorbers can be realized, for example in the electrical domain it would be relatively uncomplicated to synthesize multi-frequency or real time tunable vibration absorbers by adding electrical components in parallel. In addition by using resistance emulators in the electrical circuits, part of the absorbed vibration energy can be converted into usable power. Here an electromagnetic tuned inerter damper (E-TID) is tested experimentally using real time dynamic substructuring. A voltage compensation unit was developed in order to compensate for coil losses. This voltage compensation unit requires power, which is acquired through harvesting from the vibration energy using a resistance emulator. A power balance analysis was developed in order to ensure the device can be self sufficient. Promising experimental results, using this approach, have been obtained and are presented in this paper. The ultimate goal of this research is the development of autonomous electromagnetic vibration absorbers, able to harvest energy

  18. Development of seismic technology and reliability based on vibration tests

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Youichi [Nuclear Power Engineering Corp., Tokyo (Japan)

    1997-03-01

    This paper deals with some of the vibration tests and investigations on the seismic safety of nuclear power plants (NPPs) in Japan. To ensure the reliability of the seismic safety of nuclear power plants, nuclear power plants in Japan have been designed according to the Technical Guidelines for Aseismic Design of Nuclear Power Plants. This guideline has been developed based on technical date base and findings which were obtained from many vibration tests and investigations. Besides the tests for the guideline, proving tests on seismic reliability of operating nuclear power plants equipment and systems have been carried out. In this paper some vibration tests and their evaluation results are presented. They have crucially contributed to develop the guideline. (J.P.N.)

  19. Vibration-based damage detection algorithm for WTT structures

    Science.gov (United States)

    Nguyen, Tuan-Cuong; Kim, Tae-Hwan; Choi, Sang-Hoon; Ryu, Joo-Young; Kim, Jeong-Tae

    2016-04-01

    In this paper, the integrity of a wind turbine tower (WTT) structure is nondestructively estimated using its vibration responses. Firstly, a damage detection algorithm using changes in modal characteristics to predict damage locations and severities in structures is outlined. Secondly, a finite element (FE) model based on a real WTT structure is established by using a commercial software, Midas FEA. Thirdly, forced vibration tests are performed on the FE model of the WTT structure under various damage scenarios. The changes in modal parameters such as natural frequencies and mode shapes are examined for damage monitoring in the structure. Finally, the feasibility of the vibration-based damage detection method is numerically verified by predicting locations and severities of the damage in the FE model of the WTT structure.

  20. Analysis on China's machine tool import in 2001%2001年中国机床进口分析

    Institute of Scientific and Technical Information of China (English)

    DING Xuesheng

    2002-01-01

    @@ In 2001, China's import of machine tool and tool products has continuously kept in a great increasing. The imported total value is as much as US 3359 million,22.7% increased than that in same period in 2000. Among them, the import of metalworking machines is 2406 million, increased by 27.27% (for detail see "Statistics of China's Machine Tool Foreign Trade in 2000 and 2001",WMEM, No. 2 2002 and 2001).

  1. Vibration-based SHM System: Application to Wind Turbine Blades

    Science.gov (United States)

    Tcherniak, D.; Mølgaard, L. L.

    2015-07-01

    This study presents an vibration-based system designed for structural health monitoring of wind turbine blades. Mechanical energy is introduced by means of an electromechanical actuator mounted inside the blade. The actuator's plunger periodically hits the blade structure; the induced vibrations propagate along the blade and are measured by an array of accelerometers. Unsupervised learning is applied to the data: the vibration patterns corresponding to the undamaged blade are used to create a statistical model of the reference state. During the detection stage, the current vibration pattern is compared with the reference state, and the novelties can be associated with damage. The vibration pattern is described by the covariance matrix between the accelerometer signals. The mid-range frequencies are used: this range is above the frequencies excited by blade-wind interaction, thus ensuring a good signal-to-noise ratio. Simultaneously, the frequencies are low enough to be able to propagate the entire blade length, so good results can be obtained even using only one actuator. The system is demonstrated on a real 34m blade mounted on a test rig. Using the suggested approach, the system enables detection of, e.g., a 20cm long trailing edge opening under realistic noise conditions. It is also demonstrated that the system provides rough information about damage location. Progression of damage, if any, can also be detected.

  2. Periodic material-based vibration isolation for satellites

    Directory of Open Access Journals (Sweden)

    Xinnan Liu

    2016-01-01

    Full Text Available The vibration environment of a satellite is very severe during launch. Isolating the satellitevibrations during launch will significantly enhance reliability and lifespan, and reduce the weight of satellite structure and manufacturing cost. Guided by the recent advances in solid-state physics research, a new type of satellite vibration isolator is proposed by usingperiodic material that is hence called periodic isolator. The periodic isolator possesses a unique dynamic property, i.e., frequency band gaps. External vibrations with frequencies falling in the frequency band gaps of the periodic isolator are to be isolated. Using the elastodynamics and the Bloch-Floquet theorem, the frequency band gaps of periodic isolators are determined. A parametric study is conducted to provide guidelines for the design of periodic isolators. Based on these analytical results, a finite element model of a micro-satellite with a set of designed periodic isolators is built to show the feasibility of vibration isolation. The periodic isolator is found to be a multi-directional isolator that provides vibration isolation in the three directions.

  3. APPLICATION OF SIMULTANEOUS FEEDBACK CONTROLLER FOR FREE AND FORCED ACTIVE VIBRATIONS CONTROL

    OpenAIRE

    Rachin Goyal*, Amresh Kumar, Manoj Kumar

    2016-01-01

    Evergrowing customer demands and thus the manufacturing methods have become the backbone of global competition for a wide range of products. This has led to the development of intelligent, compact and lightweight smart machine tools. A great difficulty is faced in the design of such machine tools due to the fact that the reduction in weight results in low rigidity and poor vibration control characteristics. The induced vibrations in the system may destabilize the system and result in complete...

  4. Vibration-based condition monitoring industrial, aerospace and automotive applications

    CERN Document Server

    Randall, Robert Bond

    2010-01-01

    ""Without doubt the best modern and up-to-date text on the topic, wirtten by one of the world leading experts in the field. Should be on the desk of any practitioner or researcher involved in the field of Machine Condition Monitoring"" Simon Braun, Israel Institute of Technology Explaining complex ideas in an easy to understand way, Vibration-based Condition Monitoring provides a comprehensive survey of the application of vibration analysis to the condition monitoring of machines. Reflecting the natural progression of these systems by presenting the fundamental material

  5. Fiber-Optic Vibration Sensor Based on Multimode Fiber

    Directory of Open Access Journals (Sweden)

    I. Lujo

    2008-06-01

    Full Text Available The purpose of this paper is to present a fiberoptic vibration sensor based on the monitoring of the mode distribution in a multimode optical fiber. Detection of vibrations and their parameters is possible through observation of the output speckle pattern from the multimode optical fiber. A working experimental model has been built in which all used components are widely available and cheap: a CCD camera (a simple web-cam, a multimode laser in visible range as a light source, a length of multimode optical fiber, and a computer for signal processing. Measurements have shown good agreement with the actual frequency of vibrations, and promising results were achieved with the amplitude measurements although they require some adaptation of the experimental model. Proposed sensor is cheap and lightweight and therefore presents an interesting alternative for monitoring large smart structures.

  6. Shaft Crack Identification Based on Vibration and AE Signals

    Directory of Open Access Journals (Sweden)

    Wenxiu Lu

    2011-01-01

    Full Text Available The shaft crack is one of the main serious malfunctions that often occur in rotating machinery. However, it is difficult to locate the crack and determine the depth of the crack. In this paper, the acoustic emission (AE signal and vibration response are used to diagnose the crack. The wavelet transform is applied to AE signal to decompose into a series of time-domain signals, each of which covers a specific octave frequency band. Then an improved union method based on threshold and cross-correlation method is applied to detect the location of the shaft crack. The finite element method is used to build the model of the cracked rotor, and the crack depth is identified by comparing the vibration response of experiment and simulation. The experimental results show that the AE signal is effective and convenient to locate the shaft crack, and the vibration signal is feasible to determine the depth of shaft crack.

  7. Proposal of thermal neutron flux monitors based on vibrating wire

    CERN Document Server

    Arutunian, S G; Chung, M; Harutyunyan, G S; Lazareva, E G

    2015-01-01

    Two types of neutron monitors with fine spatial resolution are proposed based on vibrating wire. In the first type, neutrons interact with the vibrating wire, heat it, and lead to the change of natural frequency, which can be precisely measured. To increase the heat deposition during the neutron scattering, use of gadolinium layer which has the highest thermal neutron capture cross section among all elements is proposed. The second type of the monitor uses vibrating wire as a resonant target. Besides the measurement of beam profile according to the average signal, the differential signal synchronized with the wire oscillations defines the gradient of beam profile. Spatial resolution of the monitor is defined by the diameter of the wire.

  8. Comparison of Vibration-Based Damage Assessment Techniques

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Rytter, A.

    1995-01-01

    Three different vibration-based damage assessment techniques have been compared. One of the techniques uses the ratios between changes in experimentally and theoretically estimated natural frequencies, respectively, to locate a damage. The second technique relies on updating of a finite element m...

  9. ZERO TRANSMISSION AND ITS APPLICATION IN HIGH SPEED CNC MACHINE TOOLS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In order to realize high speed machining,the special requirements for the transmission and sturctrue of CNC machine tool have to be satisfied.A high speed spindle unit driven by a builtin motor is developed.An oilwater heat exchange system is used for cooling the spindle motor.The spindle is supported by Si4N3 ceramic ball angular contact bearings.An oilair lubricator is used to lubricate and cool the spindle bearings.Some special structures are taken for balancing the spindle.

  10. Nonlinearity for a parallel kinematic machine tool and its application to interpolation accuracy analysis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper is concerned with the kinematic nonlinearity measure of parallel kinematic machine tool (PKM),which depends upon differential geometry curvature.The nonlinearity can be described by the curve of the solution locus and the equal interval input of joints mapping into inequable interval output of the end-effectors.Such curing and inequation can be measured by BW curvature.So the curvature can measure the nonlinearity of PKM indirectly.Then the distribution of BW curvature in the local area and the whole workspace are also discussed.An example of application to the interpolation accuracy analysis of PKM is given to illustrate the effectiveness of this approach.

  11. Long-range vibration sensor based on correlation analysis of optical frequency-domain reflectometry signals.

    Science.gov (United States)

    Ding, Zhenyang; Yao, X Steve; Liu, Tiegen; Du, Yang; Liu, Kun; Han, Qun; Meng, Zhuo; Chen, Hongxin

    2012-12-17

    We present a novel method to achieve a space-resolved long- range vibration detection system based on the correlation analysis of the optical frequency-domain reflectometry (OFDR) signals. By performing two separate measurements of the vibrated and non-vibrated states on a test fiber, the vibration frequency and position of a vibration event can be obtained by analyzing the cross-correlation between beat signals of the vibrated and non-vibrated states in a spatial domain, where the beat signals are generated from interferences between local Rayleigh backscattering signals of the test fiber and local light oscillator. Using the proposed technique, we constructed a standard single-mode fiber based vibration sensor that can have a dynamic range of 12 km and a measurable vibration frequency up to 2 kHz with a spatial resolution of 5 m. Moreover, preliminarily investigation results of two vibration events located at different positions along the test fiber are also reported.

  12. Research on Dynamic Modeling and Application of Kinetic Contact Interface in Machine Tool

    Directory of Open Access Journals (Sweden)

    Dan Xu

    2016-01-01

    Full Text Available A method is presented which is a kind of combining theoretic analysis and experiment to obtain the equivalent dynamic parameters of linear guideway through four steps in detail. From statics analysis, vibration model analysis, dynamic experiment, and parameter identification, the dynamic modeling of linear guideway is synthetically studied. Based on contact mechanics and elastic mechanics, the mathematic vibration model and the expressions of basic mode frequency are deduced. Then, equivalent stiffness and damping of guideway are obtained in virtue of single-freedom-degree mode fitting method. Moreover, the investigation above is applied in a certain gantry-type machining center; and through comparing with simulation model and experiment results, both availability and correctness are validated.

  13. An Energy-Based Safety Evaluation Index of Blast Vibration

    Directory of Open Access Journals (Sweden)

    Mingsheng Zhao

    2015-01-01

    Full Text Available The combined peak particle velocity (PPV and frequency safety criterion for blast vibration is widely used in blasting engineering. However, some field investigations are inconsistent with this criterion. On the basis of field investigations, it is found that there are two failure modes of structures subjected to blasting seismic waves, that is, first-excursion failure and cumulative plastic damage failure. Moreover, the nature of structural responses under blast vibrations is a process of energy input, transformation, and dissipation. Therefore, an energy-based dual safety standard is proposed in this work to more comprehensively explain all failure modes of structures under blast vibrations. To this end, structures are simplified into elastic-plastic single degree of freedom (SDOF systems with bilinear restoring force models, and energy responses of SDOF systems are then determined using the Newmark-β method. From the energy responses, the maximum instantaneous input energy and hysteretic energy are selected as the basis of the dual safety criterion, because they can reflect first-excursion failure and cumulative plastic damage failure, respectively. Finally, field investigations in a blasting site in Zunyi, Guizhou province, China, are used to prove that compared to the PPV-frequency criterion the proposed energy-based dual safety criterion is more capable of assessing the damage potential of blast vibrations.

  14. Active vibration isolation of a flexible structure mounted on a vibrating elastic base

    Science.gov (United States)

    El-Sinawi, A. H.

    2004-03-01

    The problem of isolating the vibration at any location on a flexible structure mounted on a vibrating flexible base is considered using a Kalman-based active feedforward-feedback controller (KAFB) with non-collocated sensors and actuators. The control strategy developed in this study focuses on lowering the force transmitted to the structure through its vibrating elastic foundation in the presence of process and measurements noise. A state-space model of the structure is constructed from the natural frequencies and mode shapes generated via finite element modal analysis of the structure. The important aspect of the proposed control strategy is that, while it's design is based on a full order model of the physical structure (plant), its implementation is reduced to the realization of a second order estimator regardless of the order of the plant model, and with negligible effect on its accuracy and performance. Therefore, the proposed control strategy requires low computational effort, which makes it well suited for real time control applications. Another unique aspect of this control strategy is its agility and speed in compensating for any phase or magnitude mismatch between transmitted force and control force. Moreover, the stability of the control system is implicitly attained by the controllability condition posed by the Kalman filter on the model. Thus, proper choice of Kalman gains will drive the states of the structure, at the sensor location, ideally to zero. In addition to that, digital implementation of the proposed controller can be easily done considering the fact that the discrete Kalman filter is exact. Numerical simulation of the controller performance is carried out and the results are presented.

  15. MEMS-based thick film PZT vibrational energy harvester

    DEFF Research Database (Denmark)

    Lei, Anders; Xu, Ruichao; Thyssen, Anders

    2011-01-01

    We present a MEMS-based unimorph silicon/PZT thick film vibrational energy harvester with an integrated proof mass. We have developed a process that allows fabrication of high performance silicon based energy harvesters with a yield higher than 90%. The process comprises a KOH etch using a mechan......We present a MEMS-based unimorph silicon/PZT thick film vibrational energy harvester with an integrated proof mass. We have developed a process that allows fabrication of high performance silicon based energy harvesters with a yield higher than 90%. The process comprises a KOH etch using...... a mechanical front side protection of an SOI wafer with screen printed PZT thick film. The fabricated harvester device produces 14.0 μW with an optimal resistive load of 100 kΩ from 1g (g=9.81 m s-2) input acceleration at its resonant frequency of 235 Hz....

  16. New method for computer numerical control machine tool calibration: Relay method

    Institute of Scientific and Technical Information of China (English)

    LIU Huanlao; SHI Hanming; LI Bin; ZHOU Huichen

    2007-01-01

    Relay measurement method,which uses the kilogram-meter (KGM) measurement system to identify volumetric errors on the planes of computer numerical con trol (CNC) machine tools,is verified through experimental tests.During the process,all position errors on the entire plane table are measured by the equipment,which is limited to a small field.All errors are obtained first by measuring the error of the basic position near the original point.On the basis of that positional error,the positional errors far away from the original point are measured.Using this analogy,the error information on the positional points on the entire plane can be obtained.The process outlined above is called the relay meth od.Test results indicate that the accuracy and repeatability are high,and the method can be used to calibrate geometric errors on the plane of CNC machine tools after backlash errors have been well compensated.

  17. Traveling wave ultrasonic motor using polymer-based vibrator

    Science.gov (United States)

    Wu, Jiang; Mizuno, Yosuke; Tabaru, Marie; Nakamura, Kentaro

    2016-01-01

    With the characteristics of low density, low elastic modulus, and low mechanical loss, poly(phenylene sulfide) (PPS) is a promising material for fabricating lightweight ultrasonic motors (USMs). For the first time, we used PPS to fabricate an annular elastomer with teeth and glued a piece of piezoelectric-ceramic annular disk to the bottom of the elastomer to form a vibrator. To explore for a material suitable for the rotor surface coming in contact with the PPS-based vibrator, several disk-shaped rotors made of different materials were fabricated to form traveling wave USMs. The polymer-based USM rotates successfully as the conventional metal-based USMs. The experimental results show that the USM with the aluminum rotor has the largest torque, which indicates that aluminum is the most suitable for the rotor surface among the tested materials.

  18. Vibrational Spectroscopy of Microhydrated Conjugate Base Anions

    NARCIS (Netherlands)

    Asmis, K. R.; Neumark, D. M.

    2012-01-01

    Conjugate-base anions are ubiquitous in aqueous solution. Understanding the hydration of these anions at the molecular level represents a long-standing goal in chemistry. A molecular-level perspective on ion hydration is also important for understanding the surface speciation and reactivity of aeros

  19. Vision-Based Faint Vibration Extraction Using Singular Value Decomposition

    Directory of Open Access Journals (Sweden)

    Xiujun Lei

    2015-01-01

    Full Text Available Vibration measurement is important for understanding the behavior of engineering structures. Unlike conventional contact-type measurements, vision-based methodologies have attracted a great deal of attention because of the advantages of remote measurement, nonintrusive characteristic, and no mass introduction. It is a new type of displacement sensor which is convenient and reliable. This study introduces the singular value decomposition (SVD methods for video image processing and presents a vibration-extracted algorithm. The algorithms can successfully realize noncontact displacement measurements without undesirable influence to the structure behavior. SVD-based algorithm decomposes a matrix combined with the former frames to obtain a set of orthonormal image bases while the projections of all video frames on the basis describe the vibration information. By means of simulation, the parameters selection of SVD-based algorithm is discussed in detail. To validate the algorithm performance in practice, sinusoidal motion tests are performed. Results indicate that the proposed technique can provide fairly accurate displacement measurement. Moreover, a sound barrier experiment showing how the high-speed rail trains affect the sound barrier nearby is carried out. It is for the first time to be realized at home and abroad due to the challenge of measuring environment.

  20. Application of GO Methodology on Reliability Research of CNC Machine Tool%GO法在数控机床可靠性研究中的应用

    Institute of Scientific and Technical Information of China (English)

    钟志万

    2012-01-01

    The traditional reliability analysis methods are primarily concerned with the description of static structure of system, and it is hard to use them to reflect the systems dynamic operational process. A new reliability analysis method-GO methodology was introduced into reliability research of CNC machine tool. Concrete steps of GO methodology were discussed. A GO diagram model for CNC machine tool ATC ( Automatic Tool Change) was founded. Based on the state probability formula of GO methodology, precise qualitative analysis and quantitative analysis were implemented for the ATC system. A revised algorithm for shared signals in the system was proposed. The usability and correctness of GO methodology in CNC machine tool reliability analysis were verified. Through comparing with characteristics of different methods, the characteristics and advantages of GO methodology were clarified.%传统可靠性分析方法侧重于系统静态结构的描述,难以反映系统的动态运行过程.将一种新的可靠性分析方法-GO法引入到数控机床可靠性研究中,阐述了GO法分析的具体步骤,建立了数控机床刀具交换系统的GO图模型,基于GO法状态概率公式对刀具交换系统进行了精确的定量分析和定向分析,给出了系统中共有信号的修正算法,验证了GO法在数控机床可靠性评价分析中的可用性与正确性.最后,通过对几种方法特点的比较,阐明了GO法的特点和优势.

  1. Vibration active control of smart structures incorporating ER actuators and fiber optic vibration sensors based on speckle detection

    Science.gov (United States)

    Leng, Jinsong; Asundi, Anand K.

    1999-06-01

    A smart structures system based on the fiber optic sensors and ER fluids actuators have been developed to used active vibration control in this paper. There are many advantages of this optical sensor such as high accurate, simple construction and low cost. A method of sensing vibration using the detection of changes in the spatial distribution of energy in the output of a multi-mode optic fiber has been demonstrated. A multi-mode optical fiber whose diameter is 200/230 micrometers is used in the present experiment. A multi- mode optical fiber vibration sensor based on the detection of the spatial speckle has been made. The experimental test have been finished. It has been found that this fiber optic sensor has higher sensitivity and better dynamic and static properties. At the meantime, the electrorheological (ER) fluids have been used as actuator to vibration control because of it's fast strong reversible change of the rheological properties under external electric field. A smart composite beam embedded ER fluids and fiber optic vibration sensor have been made in this paper. Finally, the experiment of structural vibration active control of smart structure incorporating the ER fluids and fiber optic vibration sensor have been finished.

  2. NEW TECHNOLOGY AND MACHINE TOOL FOR THE FORMING OF THE REAR AXLE SHAFT OF LIGHT TRUCK

    Institute of Scientific and Technical Information of China (English)

    Han Yingchun; Yu Duonian; Wang Xueming

    2004-01-01

    A new technology of forward extrusion and cross rolling has been developed to process the rear axle shaft sleeve of light truck with the use of tube billets. This technology is characterized by large reductions of material, energy and cost of production and has significant economical benefits. This technology is stable and reliable. The three rolls transverse rolling mill built based on this technology has novelty construction, higher production efficiency, non-vibration and noise. The research results have been extensively applied to light trucks and farm transport with load of 1 to 3 tones.

  3. DEPENDENCE OF THE SLIDER DEFORMATION AND MACHINING PRECISION ON THE MULTIPURPOSE MACHINE-TOOL COMPLEX OF VM SERIES

    Directory of Open Access Journals (Sweden)

    Berezhnoy S. B.

    2016-04-01

    Full Text Available The article is devoted to the development of high-tech metal-working industry, as well as to the use of unmanned technology. We recommended measures to improve the accuracy and quality of manufacturing of complex and large workpieces weighing up to 100 tons. To date, the technical level of many economy sectors is largely determined by the level of the production means. Based on the engineering development there is an overall automation and mechanization of production and industry processes, construction, agriculture, transport and other industries. We analyzed forms of slide sections, of errors affecting the accuracy of the workpieces manufacturing. We made simulation of the cutting forces and sliders deformations. Solved measures increase manufacturing accuracy based on multi-purpose machine tool systems of VM series. We held the analysis of the dependence of cutting forces, a slider form on its strain in different types of processing. We obtained a graph of cutting force and precision manufacturing. We defined the optimal shape of the slider cross section to increase the rigidity and reduce the slide deformation in metal cutting

  4. Vibrational spectroscopy of microhydrated conjugate base anions.

    Science.gov (United States)

    Asmis, Knut R; Neumark, Daniel M

    2012-01-17

    Conjugate-base anions are ubiquitous in aqueous solution. Understanding the hydration of these anions at the molecular level represents a long-standing goal in chemistry. A molecular-level perspective on ion hydration is also important for understanding the surface speciation and reactivity of aerosols, which are a central component of atmospheric and oceanic chemical cycles. In this Account, as a means of studying conjugate-base anions in water, we describe infrared multiple-photon dissociation spectroscopy on clusters in which the sulfate, nitrate, bicarbonate, and suberate anions are hydrated by a known number of water molecules. This spectral technique, used over the range of 550-1800 cm(-1), serves as a structural probe of these clusters. The experiments follow how the solvent network around the conjugate-base anion evolves, one water molecule at a time. We make structural assignments by comparing the experimental infrared spectra to those obtained from electronic structure calculations. Our results show how changes in anion structure, symmetry, and charge state have a profound effect on the structure of the solvent network. Conversely, they indicate how hydration can markedly affect the structure of the anion core in a microhydrated cluster. Some key results include the following. The first few water molecules bind to the anion terminal oxo groups in a bridging fashion, forming two anion-water hydrogen bonds. Each oxo group can form up to three hydrogen bonds; one structural result, for example, is the highly symmetric, fully coordinated SO(4)(2-)(H(2)O)(6) cluster, which only contains bridging water molecules. Adding more water molecules results in the formation of a solvent network comprising water-water hydrogen bonding in addition to hydrogen bonding to the anion. For the nitrate, bicarbonate, and suberate anions, fewer bridging sites are available, namely, three, two, and one (per carboxylate group), respectively. As a result, an earlier onset of water

  5. GENERATOR VIBRATION FAULT DIAGNOSIS METHOD BASED ON ROTOR VIBRATION AND STATOR WINDING PARALLEL BRANCHES CIRCULATING CURRENT CHARACTERISTICS

    Institute of Scientific and Technical Information of China (English)

    Wan Shuting; Li Heming; Li Yonggang; Tang Guiji

    2005-01-01

    Rotor vibration characteristics are first analyzed, which are that the rotor vibration of fundamental frequency will increase due to rotor winding inter-turn short circuit fault, air-gap dynamic eccentricity fault, or imbalance fault, and the vibration of the second frequency will increase when the air-gap static eccentricity fault occurs. Next, the characteristics of the stator winding parallel branches circulating current are analyzed, which are that the second harmonics circulating current will increase when the rotor winding inter-turn short circuit fault occurs, and the fundamental circulating current will increase when the air-gap eccentricity fault occurs, neither being strongly affected by the imbalance fault. Considering the differences of the rotor vibration and circulating current characteristics caused by different rotor faults, a method of generator vibration fault diagnosis, based on rotor vibration and circulating current characteristics, is developed. Finally, the rotor vibration and circulating current of a type SDF-9 generator is measured in the laboratory to verify the theoretical analysis presented above.

  6. Microgravity Boiling Enhancement Using Vibration-Based Fluidic Technologies

    Science.gov (United States)

    Smith, Marc K.; Glezer, Ari; Heffington, Samuel N.

    2002-11-01

    Thermal management is an important subsystem in many devices and technologies used in a microgravity environment. The increased power requirements of new Space technologies and missions mean that the capacity and efficiency of thermal management systems must be improved. The current work addresses this need through the investigation and development of a direct liquid immersion heat transfer cell for microgravity applications. The device is based on boiling heat transfer enhanced by two fluidic technologies developed at Georgia Tech. The first of these fluidic technologies, called vibration-induced bubble ejection, is shown in Fig. 1. Here, an air bubble in water is held against a vibrating diaphragm by buoyancy. The vibrations at 440 Hz induce violent oscillations of the air/water interface that can result in small bubbles being ejected from the larger air bubble (Fig. 1a) and, simultaneously, the collapse of the air/water interface against the solid surface (Fig. 1b). Both effects would be useful during a heat transfer process. Bubble ejection would force vapor bubbles back into the cooler liquid so that they can condense. Interfacial collapse would tend to keep the hot surface wet thereby increasing liquid evaporation and heat transfer to the bulk liquid. Figure 2 shows the effect of vibrating the solid surface at 7.6 kHz. Here, small-scale capillary waves appear on the surface of the bubble near the attachment point on the solid surface (the grainy region). The vibration produces a net force on the bubble that pushes it away from the solid surface. As a result, the bubble detaches from the solid and is propelled into the bulk liquid. This force works against buoyancy and so it would be even more effective in a microgravity environment. The benefit of the force in a boiling process would be to push vapor bubbles off the solid surface, thus helping to keep the solid surface wet and increasing the heat transfer. The second fluidic technology to be employed in this

  7. Vibration-based monitoring and diagnostics using compressive sensing

    Science.gov (United States)

    Ganesan, Vaahini; Das, Tuhin; Rahnavard, Nazanin; Kauffman, Jeffrey L.

    2017-04-01

    Vibration data from mechanical systems carry important information that is useful for characterization and diagnosis. Standard approaches rely on continually streaming data at a fixed sampling frequency. For applications involving continuous monitoring, such as Structural Health Monitoring (SHM), such approaches result in high volume data and rely on sensors being powered for prolonged durations. Furthermore, for spatial resolution, structures are instrumented with a large array of sensors. This paper shows that both volume of data and number of sensors can be reduced significantly by applying Compressive Sensing (CS) in vibration monitoring applications. The reduction is achieved by using random sampling and capitalizing on the sparsity of vibration signals in the frequency domain. Preliminary experimental results validating CS-based frequency recovery are also provided. By exploiting the sparsity of mode shapes, CS can also enable efficient spatial reconstruction using fewer spatially distributed sensors. CS can thereby reduce the cost and power requirement of sensing as well as streamline data storage and processing in monitoring applications. In well-instrumented structures, CS can enable continued monitoring in case of sensor or computational failures.

  8. Distributed vibration fiber sensing system based on Polarization Diversity Receiver

    Science.gov (United States)

    Zhang, Junan; Jiang, Peng; Hu, Zhengliang; Hu, Yongming

    2016-10-01

    In this paper, we propose a distributed vibration fiber sensing system based on Polarization Diversity Receiver(PDR). We use Acoustic Optical Modulator(AOM) to generate pulse light and an unbalanced M-Z interferometer to generate two pulse light with a certain time delay in the same period. As the pulse lights propagating in fibers, the Backward Rayleigh scattering lights will interfere with each other. The vibration on the fiber will change the length and refractive index of fiber which results in the change of the phase of the interference signal. Hence, one arm of the M-Z interferometer is modulated by a sinusoidal phase-generated carrier(PGC) signal, and PGC demodulation algorithm has been used to acquire phase information from the Backward Rayleigh scattering lights. In order to overcome the influence of polarization-induced fading and enhance Signal Noise Ratio(SNR), we set a PDR before the photo detector. The Polarization Diversity Receiver segregates the interfere light into two lights with orthogonal states of polarization. Hence, there is always one channel has a better interfere light signal. The experiments are presented to verify the effectiveness of the distributed vibration fiber sensing system proposed.

  9. Research of Air-Magnet Active Vibration Isolation System Based on H∞ Control

    Directory of Open Access Journals (Sweden)

    Wen Xianglong

    2015-01-01

    Full Text Available Considering the uncertainty of air-magnet active vibration isolation system (AMAVIS, passive vibration isolation was combined with active vibration isolation, which adopted H∞ control strategies. System identification method was used to get the channel model. By adopting mixed sensitivity design strategy, weighting functions were chosen and H∞ controller was designed. Both simulation results and experimental results show AMAVIS based on H∞ control had satisfying effect of vibration reduction in assigned frequency band.

  10. A Vibration Control Method for the Flexible Arm Based on Energy Migration

    OpenAIRE

    Yushu Bian; Zhihui Gao; Ming Fan

    2015-01-01

    A vibration control method based on energy migration is proposed to decrease vibration response of the flexible arm undergoing rigid motion. A type of vibration absorber is suggested and gives rise to the inertial coupling between the modes of the flexible arm and the absorber. By analyzing 1 : 2 internal resonance, it is proved that the internal resonance can be successfully created and the exchange of vibration energy is existent. Due to the inertial coupling, the damping enhancement effect...

  11. Configuration design and accuracy analysis of a novel magneto rheological finishing machine tool for concave surfaces with small radius of curvature

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Henan; Chen, Mingjun [Harbin Institute of Technology, Harbin (China); Yu, Bo; Zhen, Fang [China Electronics Technology Group Corporation No.26 Research Institute, Chongqing (China)

    2016-07-15

    Magnetorheological finishing (MRF) is a computer-controlled deterministic polishing technique that is widely used in the production of high-quality optics. In order to overcome the defects of existing MRF processes that are unable to achieve concave surfaces with small radius of curvature, a configuration method of a novel structured MRF machine tool using small ball-end permanent-magnet polishing head is proposed in this paper. The preliminary design focuses on the structural configuration of the machine, which includes the machine body, motion units and accessory equipment, and so on. Structural deformation and fabrication accuracy of the machine are analyzed theoretically, in which the reasonable structure sizes, manufacturing errors and assembly errors of main structural components are given for configuration optimization. Based on the theoretical analysis, a four-axes linkage MRF machine tool is developed. Preliminary experiments of spot polishing are carried out and the results indicate that the proposed MRF process can achieve stable polishing area which meets requirement of deterministic polishing. A typical small-bore complex component is polished on the developed device and fine surface quality is obtained with sphericity of the finished spherical surfaces 1.3 μm and surface roughness Ra less than 0.018 μm.

  12. A Vibration Control Method for the Flexible Arm Based on Energy Migration

    Directory of Open Access Journals (Sweden)

    Yushu Bian

    2015-01-01

    Full Text Available A vibration control method based on energy migration is proposed to decrease vibration response of the flexible arm undergoing rigid motion. A type of vibration absorber is suggested and gives rise to the inertial coupling between the modes of the flexible arm and the absorber. By analyzing 1 : 2 internal resonance, it is proved that the internal resonance can be successfully created and the exchange of vibration energy is existent. Due to the inertial coupling, the damping enhancement effect is revealed. Via the inertial coupling, vibration energy of the flexible arm can be dissipated by not only the damping of the vibration absorber but also its own enhanced damping, thereby effectively decreasing vibration. Through numerical simulations and analyses, it is proven that this method is feasible in controlling nonlinear vibration of the flexible arm undergoing rigid motion.

  13. Vibrational dynamics of Zr-based bulk metallic glasses

    Institute of Scientific and Technical Information of China (English)

    Aditya M.VORA

    2009-01-01

    The vibrational dynamics of some Zr-based bulkmetallic glasses were studied at room temperature in terms of phonon eigen frequencies of longitudinal and transverse modes employing three different approaches proposed by Hubbard-Beeby (HB), Takeno-Goda (TG) and Bhatia-Singh (BS). The well recognized model potential is employed successfully to explain electron-ion interaction in the metallic glass. The present findings of phonon dispersion curve are found to be in fair agreement with available theoretical as well as experimental data. The thermodynamic properties obtained by the HB and TG approaches are found to be much lower than those obtained by the BS approach.

  14. Vibrational imaging based on stimulated Raman scattering microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nandakumar, P; Kovalev, A; Volkmer, A [3. Physikalisches Institut, Universitaet Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart (Germany)], E-mail: a.volkmer@physik.uni-stuttgart.de

    2009-03-15

    A stimulated Raman scattering microscope with near-infrared picosecond laser pulses at high repetition rates (76 MHz) and radio-frequency lock-in detection is accomplished. Based on stimulated Raman loss detection, we demonstrate noninvasive point-by-point vibrational mapping of chemical and biological samples with high sensitivity and without the requirement for labeling of the sample with natural or artificial fluorophores. We experimentally demonstrate a major benefit of this technique, which is the capability to respond exclusively to the linear Raman-resonance properties of the sample, thus allowing a direct quantitative interpretation of image contrast in terms of the number density of Raman-active modes.

  15. Vibrational imaging based on stimulated Raman scattering microscopy

    Science.gov (United States)

    Nandakumar, P.; Kovalev, A.; Volkmer, A.

    2009-03-01

    A stimulated Raman scattering microscope with near-infrared picosecond laser pulses at high repetition rates (76 MHz) and radio-frequency lock-in detection is accomplished. Based on stimulated Raman loss detection, we demonstrate noninvasive point-by-point vibrational mapping of chemical and biological samples with high sensitivity and without the requirement for labeling of the sample with natural or artificial fluorophores. We experimentally demonstrate a major benefit of this technique, which is the capability to respond exclusively to the linear Raman-resonance properties of the sample, thus allowing a direct quantitative interpretation of image contrast in terms of the number density of Raman-active modes.

  16. The Application of the GM (1,1) Metabolism Model to Error Data Processing of NC Machine Tools

    Institute of Scientific and Technical Information of China (English)

    LIAO De-gang; XIONG Xiao-hong

    2003-01-01

    This paper applied the gray system theory to error data processing of NC machine tools ac cording to the characteristic. It presented the gray metabolism model of error data processing. The test method for the model needs less capacity. Practice proved that the method is simple, calculation is easy, and results are exact.

  17. "A WAR OF MACHINERY”: the British Machine Tool Industry and Arming the Western Front, 1914-1916

    Directory of Open Access Journals (Sweden)

    Roger Lloyd-Jones

    2008-01-01

    Full Text Available According to David Lloyd George, Britain’s first Minister of Munitions, World War L “the Great War” was a “war of machinery,” and required unprecedented supplies of ammunition and the machine tools necessary to make them. In the early phase of the conflict, when the importance of machine tools was not fully recognized, a shortage of ammunition on the western front precipitated a military and political crisis, and led to the formation of the Ministry of Munitions. A trade-off between quantity and quality of ammunition shell (the machined outer metal casing was a product of the Ministry directive to increase output as both makers and users of machine tools came under intense pressure to reach their goals. British engineering achieved huge increases in ammunition output in preparation for the Somme offensive, but the complexities of the supply chain meant that makers and users of machine tools put them to use to make ammunition of a type and quality that was to prove defective.

  18. Magnetic field sensor using a polymer-based vibrator

    Science.gov (United States)

    Wu, Jiang; Hasebe, Kazuhiko; Mizuno, Yosuke; Tabaru, Marie; Nakamura, Kentaro

    2016-09-01

    In this technical note, a polymer-based magnetic sensor with a high resolution was devised for sensing the high magnetic field. It consisted of a bimorph (vibrator) made of poly (phenylene sulfide) (PPS) and a phosphor-bronze foil glued on the free end of the bimorph. According to Faraday’s law of induction, when a magnetic field in the direction perpendicular to the bimorph was applied, the foil cut the magnetic flux, and generated an alternating voltage across the leads at the natural frequency of the bimorph. Because PPS has low mechanical loss, low elastic modulus, and low density, high vibration velocity can be achieved if it is employed as the elastomer of the bimorph. The devised sensor was tested in the magnetic field range of 0.1-570 mT and exhibited a minimum detectable magnetic field of 0.1 mT. At a zero-to-peak driving voltage of 60 V, the sensitivity of the PPS-based magnetic sensor reached 10.5 V T-1, which was 1.36 times the value of the aluminum-based magnetic sensor with the same principle and dimensions.

  19. Law of Torsional Vibration and Discussion on Vibration Suppression Based on Helicopter/Engine System

    Science.gov (United States)

    Miao, Lizhen; Zhang, Haibo; Ning, Jingtao

    2016-04-01

    With both the advantages like attacking close targets and the disadvantages especially like dynamic coupling, helicopter deserves more investigations these days. This paper did dynamic study both in a simplified and a multi-degree of freedom, comprehensive helicopter model, so that to reveal the law of torsional vibration. In the simplified model, the law how arbitrary parameter affects the first-order vibration mode, is discussed. Then, the validation is done in a multi-degree of freedom model by means of the fast Fourier transformation (FFT) method. In this case, how the low-frequency vibration mode relates with the first-order vibration mode is clearly presented, as well as the research direction to design a filter. Lastly, a simple filter is designed with some simulations.

  20. VIBRATIONS DETECTION IN INDUSTRIAL PUMPS BASED ON SPECTRAL ANALYSIS TO INCREASE THEIR EFFICIENCY

    Directory of Open Access Journals (Sweden)

    Belhadef RACHID

    2016-01-01

    Full Text Available Spectral analysis is the key tool for the study of vibration signals in rotating machinery. In this work, the vibration analy-sis applied for conditional preventive maintenance of such machines is proposed, as part of resolved problems related to vibration detection on the organs of these machines. The vibration signal of a centrifugal pump was treated to mount the benefits of the approach proposed. The obtained results present the signal estimation of a pump vibration using Fourier transform technique compared by the spectral analysis methods based on Prony approach.

  1. Transducers for Sound and Vibration - FEM Based Design

    DEFF Research Database (Denmark)

    Liu, Bin

    2001-01-01

    Design of transducers for measurement of vibration (piezoelectric accelerometers) and sound (condenser microphones) is a very labour intensive work. The design work is mostly based on experience and on simple analogies to electrical circuit design. Often a time consuming itterative loop is used......: Specification of the transducer, production of a physical prototype, measurements on the prototype, changed specification of the transducer etc. Furthermore are many transducers made based on customer requirements which also increases the amount of required design work. For these reasons there is a need...... for methods that can reduce the design time consumption and the number of itterations. The present work proposes to use finite element based programs for simulating the behaviour of a transducer with a given set of specifications. A simulation program for accelerometers was developed and has been tested...

  2. Inventory management performance in machine tool SMEs: What factors do influence them?

    Directory of Open Access Journals (Sweden)

    Rajeev Narayana Pillai

    2010-12-01

    Full Text Available Small and Medium Enterprises (SMEs are one of the principal driving forces in the development of an economy because of its significant contribution in terms of number of enterprises, employment, output and exports in most developing as well as developed countries. But SMEs, particularly in developing countries like India, face constraints in key areas such as technology, finance, marketing and human resources. Moreover these SMEs have been exposed to intense competition since early 1990s because of globalization. However, globalization, the process of continuing integration of the countries in the world has opened up new opportunities for SMEs of developing countries to cater to wider international market which brings out the need for these SMEs to develop competitiveness for their survival as well as growth. It is observed from literature that pursuing appropriate IM practice is one of the ways of acquiring competitiveness among others, by effectively managing and minimizing inventory investment. Inventory management can therefore be one of the crucial determinants of competitiveness as well as operational performance of SMEs in inventory intensive manufacturing industries. The key issue is whether Indian SMEs pursue better IM practices with an intension to reduce their inventory cost and enhance their competitiveness. If so, what are the IM practices pursued by these enterprises? What are the factors which influence the inventory cost and IM performance of enterprises? These questions have been addressed in this study with reference to machine tool SMEs located in the city of Bangalore, India.

  3. Bayesian zero-failure reliability modeling and assessment method for multiple numerical control (NC) machine tools

    Institute of Scientific and Technical Information of China (English)

    阚英男; 杨兆军; 李国发; 何佳龙; 王彦鹍; 李洪洲

    2016-01-01

    A new problem that classical statistical methods are incapable of solving is reliability modeling and assessment when multiple numerical control machine tools (NCMTs) reveal zero failures after a reliability test. Thus, the zero-failure data form and corresponding Bayesian model are developed to solve the zero-failure problem of NCMTs, for which no previous suitable statistical model has been developed. An expert−judgment process that incorporates prior information is presented to solve the difficulty in obtaining reliable prior distributions of Weibull parameters. The equations for the posterior distribution of the parameter vector and the Markov chain Monte Carlo (MCMC) algorithm are derived to solve the difficulty of calculating high-dimensional integration and to obtain parameter estimators. The proposed method is applied to a real case; a corresponding programming code and trick are developed to implement an MCMC simulation in WinBUGS, and a mean time between failures (MTBF) of 1057.9 h is obtained. Given its ability to combine expert judgment, prior information, and data, the proposed reliability modeling and assessment method under the zero failure of NCMTs is validated.

  4. Efficient thermal error prediction in a machine tool using finite element analysis

    Science.gov (United States)

    Mian, Naeem S.; Fletcher, Simon; Longstaff, Andrew P.; Myers, Alan

    2011-08-01

    Thermally induced errors have a major significance on the positional accuracy of a machine tool. Heat generated during the machining process produces thermal gradients that flow through the machine structure causing linear and nonlinear thermal expansions and distortions of associated complex discrete structures, producing deformations that adversely affect structural stability. The heat passes through structural linkages and mechanical joints where interfacial parameters such as the roughness and form of the contacting surfaces affect the thermal resistance and thus the heat transfer coefficients. This paper presents a novel offline technique using finite element analysis (FEA) to simulate the effects of the major internal heat sources such as bearings, motors and belt drives of a small vertical milling machine (VMC) and the effects of ambient temperature pockets that build up during the machine operation. Simplified models of the machine have been created offline using FEA software and evaluated experimental results applied for offline thermal behaviour simulation of the full machine structure. The FEA simulated results are in close agreement with the experimental results ranging from 65% to 90% for a variety of testing regimes and revealed a maximum error range of 70 µm reduced to less than 10 µm.

  5. Wear resistance of machine tools' bionic linear rolling guides by laser cladding

    Science.gov (United States)

    Wang, Yiqiang; Liu, Botao; Guo, Zhengcai

    2017-06-01

    In order to improve the rolling wear resistance (RWR) of linear rolling guides (LRG) as well as prolong the life of machine tools, various shape samples with different units spaces ranged from 1 to 5 mm are designed through the observation of animals in the desert and manufactured by laser cladding. Wear resistance tests reproducing closely the real operational condition are conducted by using a homemade linear reciprocating wear test machine, and wear resistance is evaluated by means of weight loss measurement. Results indicate that the samples with bionic units have better RWR than the untreated one, of which the reticulate treated sample with unit space 3 mm present the best RWR. More specifically, among the punctuate treated samples, the mass loss increases with the increase of unit space; among the striate treated samples, the mass loss changes slightly with the increase of unit space, attaining a minimum at the unit space of 4 mm; among the reticulate treated samples, with the increase of unit space, the mass loss initially decreases, but turns to increase after reaching a minimum at the unit space of 3 mm. Additionally, the samples with striate shape perform better wear resistance than the other shape groups on the whole. From the ratio value of laser treated area to contacted area perspective, that the samples with ratio value between 0.15 and 0.3 possess better wear resistance is concluded.

  6. Kinematic Modelling and Control Simulation for 1PS+3TPS Type Hybrid Machine Tool

    Institute of Scientific and Technical Information of China (English)

    FAN Shouwen; WANG Xiaobing; HUANG Hongzhong

    2006-01-01

    A structure scheme for a novel hybrid machine tool (HMT) is proposed in this paper. In the scheme, a 4-DOFs 1PS+3TPS type spatial hybrid mechanism is utilized as main feed mechanism, with assistance of a two direction movable worktable, multi-coordinates NC machining can be realized. In the main feed mechanism, fixed platform is connected with moving platform by three TPS driving links and one PS driving link, one translation DOF and three rotation DOFs can be achieved by it. This type HMT enjoys some advantages over its conventional counterparts:large workspace,good dexterity,etc. Closed form inverse displacement analysis model and inverse kinematic model for main feed mechanism are established. A fuzzy PID control scheme for machining control of HMTs with high tracking precision is proposed aiming at highly nonlinear, tightly coupled and uncertain characteristic of HMTs. Simulation researches for fuzzy PID control of HMTs are carried out. Simulation Results demonstrate the effectiveness and the Robostness of the fuzzy PID controller.

  7. 数控机床典型电气故障诊断与维修%Diagnosis and Maintenance of Electrical Breakdown of CNC Machine Tools

    Institute of Scientific and Technical Information of China (English)

    张晶辉

    2016-01-01

    With the development of numerical control technology ,the maintenance of CNC machine tools has become increasingly important .A CNC machine tool is mainly composed of electrical ,mechanical and hydraulic components .This paper discussed the diagnosis and maintenance of electrical breakdown of CNC machine tools .Through the understanding of the electrical principle of machine tools ,we can improve the efficience of repair and maintenance of the electrical system of machine tools .%随着数控技术的发展,数控机床的维修已越来越重要。主要对数控机床电气部分的故障诊断与维修进行了介绍。基于对机床电气原理的认识,可以更好地对机床电气系统进行维修与维护。

  8. Efficiency Enhancement of a Cantilever-Based Vibration Energy Harvester

    Directory of Open Access Journals (Sweden)

    Ali E. Kubba

    2013-12-01

    Full Text Available Extracting energy from ambient vibration to power wireless sensor nodes has been an attractive area of research, particularly in the automotive monitoring field. This article reports the design, analysis and testing of a vibration energy harvesting device based on a miniature asymmetric air-spaced cantilever. The developed design offers high power density, and delivers electric power that is sufficient to support most wireless sensor nodes for structural health monitoring (SHM applications. The optimized design underwent three evolutionary steps, starting from a simple cantilever design, going through an air-spaced cantilever, and ending up with an optimized air-spaced geometry with boosted power density level. Finite Element Analysis (FEA was used as an initial tool to compare the three geometries’ stiffness (K, output open-circuit voltage (Vave, and average normal strain in the piezoelectric transducer (εave that directly affect its output voltage. Experimental tests were also carried out in order to examine the energy harvesting level in each of the three designs. The experimental results show how to boost the power output level in a thin air-spaced cantilever beam for energy within the same space envelope. The developed thin air-spaced cantilever (8.37 cm3, has a maximum power output of 2.05 mW (H = 29.29 μJ/cycle.

  9. Vibration analysis based on surface acoustic wave sensors

    Directory of Open Access Journals (Sweden)

    Gnadinger Alfred P.

    2015-01-01

    Full Text Available It is important to know, whether a civil engineering structure is safe or unsafe. One way to determine this is to measure vibrations at critical locations and feeding this data into an appropriate algorithm. Albido Corporation has developed wireless strain sensors based on surface acoustic wave (SAW principles that are mainly employed on rotating structures and in harsh environments. Albido's sensors could also be used to measure vibrations in civil engineering structures. They are small (~1 × 3 mm, passive and inexpensive (< 1$ in volume. They are powered by the electromagnetic field emanating from the antenna of a Reader System, similar to an RFID. The Reader System is essentially a computer with special software and has signal processing capability. One Reader System can service a multitude of sensors. The Reader antenna has to be within the reading range of the sensor. If large distances are required, a small electronic component acting as a Reader System can be placed within the reading range of the sensor that receives the sensor signal, generates a radio signal and encodes the sensor information on the radio signal. Then, the final data processing center can be placed anywhere.

  10. Development of a semi-active dynamic vibration absorber for longitudinal vibration of propulsion shaft system based on magnetorheological elastomer

    Science.gov (United States)

    Liu, Gaoyu; Lu, Kun; Zou, Donglin; Xie, Zhongliang; Rao, Zhushi; Ta, Na

    2017-07-01

    The control of the longitudinal pulsating force and the vibration generated is very important to improve the stealth performance of a submarine. Magnetorheological elastomer (MRE) is a kind of intelligent composite material, whose mechanical properties can be continuously, rapidly and reversibly controlled by an external magnetic field. It can be used as variable-stiffness components in the design of a semi-active dynamic vibration absorber (SDVA), which is one of the effective means of longitudinal vibration control. In this paper, an SDVA is designed based on the MRE’s magnetic-induced variable stiffness characteristic. Firstly, a mechanical model of the propulsion shaft system with the SDVA is proposed, theoretically discussed and numerically validated. Then, the mechanical performance of the MRE under different magnetic fields is tested. In addition, the magnetic circuit and the overall structure of the SDVA are designed. Furthermore, electromagnetic and thermodynamic simulations are carried out to guarantee the structural design. The frequency shift property of the SDVA is found through dynamic simulations and validated by a frequency shift experiment. Lastly, the vibration absorption capacity of the SDVA is investigated. The results show that the magnetorheological effect of the MRE and the frequency shift of the SDVA are obvious; the SDVA has relatively acceptable vibration absorption capacity.

  11. An electroactive polymer based concept for vibration reduction via adaptive supports

    Science.gov (United States)

    Wolf, Kai; Röglin, Tobias; Haase, Frerk; Finnberg, Torsten; Steinhoff, Bernd

    2008-03-01

    A concept for the suppression of resonant vibration of an elastic system undergoing forced vibration coupled to electroactive polymer (EAP) actuators based on dielectric elastomers is demonstrated. The actuators are utilized to vary the stiffness of the end support of a clamped beam, which is forced to harmonic vibration via a piezoelectric patch. Due to the nonlinear dependency of the elastic modulus of the EAP material, the modulus can be changed by inducing an electrostrictive deformation. The resulting change in stiffness of the EAP actuator leads to a shift of the resonance frequencies of the vibrating beam, enabling an effective reduction of the vibration amplitude by an external electric signal. Using a custom-built setup employing an aluminum vibrating beam coupled on both sides to electrodized strips of VHB tape, a significant reduction of the resonance amplitude was achieved. The effectiveness of this concept compared to other active and passive concepts of vibration reduction is discussed.

  12. Thermal error separating and modeling for heavy-duty CNC machine tools%重型数控机床热误差的分离与建模

    Institute of Scientific and Technical Information of China (English)

    崔岗卫; 高栋; 姚英学

    2012-01-01

    To solve the problem of thermal error of heavy-duty CNC machine tools, a thermal error separating and modeling approach based on linear regression theory is proposed. Firstly, the thermal errors are separated from geometric error to get thermal error parameters. Secondly, based on temperature sensors optimizing distri- bution strategies, like main factor strategy and irrelevance strategy, the key points of thermal errors are select- ed. Finally, a multiple linear regression model is constructed for thermal errors, and an experiment is carried out on a TK6920 heavy-duty CNC floor-type boring and milling machine tool, and the results indicate that the thermal error of column is reduced from 0. 45 mm and 0.25 mm to 0. 13 mm and 0.09 mm in X and W direc- tions, that is 71% and 64% of thermal error can be compensated with this model. Error compensation tech- nology can reduce the thermal error of heavy-duty CNC machine tools, therefore the manufacturing precision can be improved.%为解决重型数控机床热误差严重的问题,提出一种基于线性回归的热误差分离和建模方法.对机床的几何误差与热误差进行分离,得到相应的热误差参数;结合主因素和互不相关等温度传感器优化布置策略,选出相应的热误差关键点;采用线性回归理论进行热误差的建模.在一台型号为TK6920的重型数控落地铣镗床上进行了立柱热倾斜误差补偿实验.结果表明:利用所建立的热误差模型进行补偿,立柱在X和W方向的直线度误差分别由0.45 mm和0.25 mm降到了0.13 mm和0.09 mm,补偿率分别为71%和64%.采用误差补偿技术可降低重型数控机床的热误差,从而提高其加工精度.

  13. Reactor vibration reduction based on giant magnetostrictive materials

    Science.gov (United States)

    Rongge, Yan; Weiying, Liu; Yuechao, Wu; Menghua, Duan; Xiaohong, Zhang; Lihua, Zhu; Ling, Weng; Ying, Sun

    2017-05-01

    The vibration of reactors not only produces noise pollution, but also affects the safe operation of reactors. Giant magnetostrictive materials can generate huge expansion and shrinkage deformation in a magnetic field. With the principle of mutual offset between the giant magnetostrictive force produced by the giant magnetostrictive material and the original vibration force of the reactor, the vibration of the reactor can be reduced. In this paper, magnetization and magnetostriction characteristics in silicon steel and the giant magnetostrictive material are measured, respectively. According to the presented magneto-mechanical coupling model including the electromagnetic force and the magnetostrictive force, reactor vibration is calculated. By comparing the vibration of the reactor with different inserted materials in the air gaps between the reactor cores, the vibration reduction effectiveness of the giant magnetostrictive material is validated.

  14. The Acceleration/Deceleration Control Algorithm Based on Trapezoid-Curve Jerk in CNC Machining

    Directory of Open Access Journals (Sweden)

    Guoyong Zhao

    2013-02-01

    Full Text Available In this study, we propose the acceleration/deceleration control algorithm based on trapezoid-curve jerk in CNC machining. In aviation and mould and die industry, it is much significant to achieve high accuracy CNC machining on complex profile parts. The unsmooth Acceleration/Deceleration (ab. Acc/Dec control in feed movement is one of the main reasons to bring about machine tools impact and vibration in practical machining. After analyzing the CNC machine tools dynamic model, an Acc/Dec control algorithm based on trapezoid-curve jerk is put forward in order to avoid step change in jerk curve in the study; Moreover, the motion profile smooth control approach based on continuous jerk is developed in details to decrease machine tools impact according to various kinematics constraint conditions, such as the maximum acceleration, the maximum jerk, the machining program segment displacement, the instruction feedrate and so on; Finally, the developed Acc/Dec approach and the traditional linear Acc/Dec approach are compared in the CNC experimental table. The results reveal that the developed approach can achieve more smooth and flexible motion profile, which is helpful to minish machine tools impact and enhance parts machining surface quality.

  15. 通用多轴数控机床误差建模与指令修正方法的研究%Research on General Error Modeling and Instructions Correction Method for Multi-axis CNC Machine Tools

    Institute of Scientific and Technical Information of China (English)

    范晋伟; 王晓峰; 李云

    2013-01-01

    How to improve the machining accuracy of multi-axis CNC machine tools with least investment is the hot spot of todays social research. In order to solve the problem,modifying the instructions of NC machine to improve the accuracy is the most effective method. The multi-axis CNC machine tool was analyzed with multi-body theory. The general error model of multi-axis CNC machine tools was established. Based on these,a thorough study on rotary error was made. Taking C-A type machine tool as example,the in-terative solution method was used to get the precise NC instructions of rotary angle.%  机床已经成为工业领域不可缺少的加工工具,特别是多轴机床的出现改变了传统的加工方式。针对如何提高多轴数控机床的精度展开研究,应用多体理论建立了通用多轴数控机床误差模型,在此基础上,给出了多轴数控机床平移和转动数控精密指令求解方法。并以C-A型五轴数控机床为例,采用迭代的方法求出了回转角的精密指令值。

  16. 机床热变形及热误差优化研究%Study on Optimization of Thermal Deformation and Thermal Error on Machine Tools

    Institute of Scientific and Technical Information of China (English)

    吕长飞; 吴小玉; 朱秋菊

    2014-01-01

    The test-analysis of effects on machine tool of motorized spindle temperature risings,thermal deformations and environ-ment temperature in summer and in winter especially was presented,in order to reduce effects on machining precision by thermal de-formation. Also the thermal error modeling based on using back propagation (BP)neural networking Volterra nonlinear system was re-alized. The analysis results indicate the environmental temperature effected by thermal diffusivities from headstock is raised rapidly in summer;thermal diffusivities of the machine tool is fast and the temperature is rising visibly on headstock in winter,and the environ-ment temperature is almost in constant. The thermal deformations are similar in rules,but have some little difference in values between in summer and in winter for a same machine. It is validated by experiments that the model has merit of high predicative precision, which provides reference for compensation of real time thermal error in CNC machine tool.%为减少热变形对精密加工精度影响,对夏冬两季节机床主轴箱上温升和热变形及环境温度的影响进行了测试分析,并采用BP神经网络模型化的Volterra级数非线性系统实现热误差建模。分析结果表明:夏天环境温度受主轴箱散热影响而温度迅速升高;冬季机床散热较快,主轴箱上温升比较明显,环境温度几乎不变;同一台机床在夏季和冬季的热变形规律相似而变形量稍有不同。通过实验验证了该模型具有预测精度高的优点,为数控机床热误差实时补偿提供了参考。

  17. Stacked and folded piezoelectrets for vibration-based energy harvesting

    Science.gov (United States)

    Sessler, G. M.; Pondrom, P.; Zhang, X.

    2016-08-01

    Vibration-based energy harvesting with piezoelectrets can be significantly improved by using multiple layers of these materials. In particular, folding or stacking of piezoelectrets or a combination of these methods results in increased power output of the energy harvesters. The possibilities of these procedures are explored, together with the effect of seismic mass, resonance frequency, and terminating resistance. It is found that with seismic masses of about 20 g and using radiation-crosslinked polypropylene (IXPP) as a piezoelectret, power outputs of up to 80 µW can be achieved for an acceleration of 1 g. Expected dependencies of generated power on frequency, folding and stacking parameters, in particular number of layers, and on seismic mass, are confirmed.

  18. Electret transducer for vibration-based energy harvesting

    Energy Technology Data Exchange (ETDEWEB)

    Hillenbrand, J., E-mail: j.hillenbrand@nt.tu-darmstadt.de; Sessler, G. M. [Institute for Telecommunications Technology, Technische Universität Darmstadt, Merckstr. 25, 64283 Darmstadt (Germany); Pondrom, P. [Institute for Telecommunications Technology, Technische Universität Darmstadt, Merckstr. 25, 64283 Darmstadt (Germany); System Reliability and Machine Acoustics SzM, Technische Universität Darmstadt, Magdalenenstr. 4, 64289 Darmstadt (Germany)

    2015-05-04

    Vibration-based electret energy harvesters with soft cellular spacer rings are presented. These harvesters are closely related to recently introduced electret accelerometers; however, their development targets are partially differing. Various harvesters with seismic masses from 8 to 23 g and surface potentials in the 500 V regime were built and characterized and powers of up to 8 μW at about 2 kHz and an acceleration of 1 g were measured. An analytical model is presented which, for instance, allows the calculation of the frequency response of the power output into a given load resistance. Finally, experimental and calculated results are compared.

  19. Axiomatic Design and Fabrication of Composite Structures - Applications in Robots, Machine Tools, and Automobiles

    Science.gov (United States)

    Lee, Dai Gil; Suh, Nam Pyo

    2005-11-01

    The idea that materials can be designed to satisfy specific performance requirements is relatively new. With high-performance composites, however, the entire process of designing and fabricating a part can be worked out before manufacturing. The purpose of this book is to present an integrated approach to the design and manufacturing of products from advanced composites. It shows how the basic behavior of composites and their constitutive relationships can be used during the design stage, which minimizes the complexity of manufacturing composite parts and reduces the repetitive "design-build-test" cycle. Designing it right the first time is going to determine the competitiveness of a company, the reliability of the part, the robustness of fabrication processes, and ultimately, the cost and development time of composite parts. Most of all, it should expand the use of advanced composite parts in fields that use composites only to a limited extent at this time. To achieve these goals, this book presents the design and fabrication of novel composite parts made for machine tools and other applications like robots and automobiles. This book is suitable as a textbook for graduate courses in the design and fabrication of composites. It will also be of interest to practicing engineers learning about composites and axiomatic design. A CD-ROM is included in every copy of the book, containing Axiomatic CLPT software. This program, developed by the authors, will assist readers in calculating material properties from the microstructure of the composite. This book is part of the Oxford Series on Advanced Manufacturing.

  20. Temperature variable optimization for precision machine tool thermal error compensation on optimal threshold

    Science.gov (United States)

    Zhang, Ting; Ye, Wenhua; Liang, Ruijun; Lou, Peihuang; Yang, Xiaolan

    2013-01-01

    Machine tool thermal error is an important reason for poor machining accuracy. Thermal error compensation is a primary technology in accuracy control. To build thermal error model, temperature variables are needed to be divided into several groups on an appropriate threshold. Currently, group threshold value is mainly determined by researchers experience. Few studies focus on group threshold in temperature variable grouping. Since the threshold is important in error compensation, this paper arms to find out an optimal threshold to realize temperature variable optimization in thermal error modeling. Firstly, correlation coefficient is used to express membership grade of temperature variables, and the theory of fuzzy transitive closure is applied to obtain relational matrix of temperature variables. Concepts as compact degree and separable degree are introduced. Then evaluation model of temperature variable clustering is built. The optimal threshold and the best temperature variable clustering can be obtained by setting the maximum value of evaluation model as the objective. Finally, correlation coefficients between temperature variables and thermal error are calculated in order to find out optimum temperature variables for thermal error modeling. An experiment is conducted on a precise horizontal machining center. In experiment, three displacement sensors are used to measure spindle thermal error and twenty-nine temperature sensors are utilized to detect the machining center temperature. Experimental result shows that the new method of temperature variable optimization on optimal threshold successfully worked out a best threshold value interval and chose seven temperature variables from twenty-nine temperature measuring points. The model residual of z direction is within 3 μm. Obviously, the proposed new variable optimization method has simple computing process and good modeling accuracy, which is quite fit for thermal error compensation.

  1. Study of the stiffness for predicting the accuracy of machine tools; Estudio de la rigidez para la prediccion de la precision de las maquinas-herramientas

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, N.; Campa, F.J.; Fernandez Valdivielso, A.; Alonso, U.; Olvera, D.; Compean, F.I.

    2010-07-01

    Machining processes are frequently faced with the challenge of achieving more and more precision and surface qualities. These requirements are usually attained taking into account some process variables, including the cutting parameters and the use or not of refrigerant, leaving aside the mechanical aspects associated with the influence of machine tool itself. There are many sources of error linked with machine-workpiece interaction, but, in general, we can summarize them into two types of error: quasi-static and dynamic. This paper shows the influence of quasi-static error caused by low machine rigidity on the accuracy applied on two very different processes: turning and grinding. For the study of the static stiffness of these two machines, two different methods are proposed, both of them equally valid. The first one is based on separated parameters and the second one on finite elements. (Author).

  2. Piezo Ceramic Actuators versus High Magnetostrictive Actuators in the Active control of Tool Vibration

    OpenAIRE

    Andrén, Linus; Håkansson, Lars; Claesson, Ingvar; Lagö, Thomas L.

    1999-01-01

    In the turning operation chatter or vibration is a frequent problem, which affects the result of the machining, and, in particular, the surface finish. Tool life is also influenced by vibration. Severe acoustic noise in the working environment frequently occurs as a result of dynamic motion between the cutting tool and the workpiece. These problems can be reduced by active control of machine-tool vibration. In the active control system for the control of tool vibration a tool holder construct...

  3. Applicability of a vibration sensor based on the optical fiber Bragg grating in radiation environment

    CERN Document Server

    Fujita, K; Nakazawa, M; Takahashi, H

    2003-01-01

    Fiber Bragg grating (FBG) is a kind of an optical device developing rapidly in these years and it has various excellent characteristics as a sensor. To investigate applicability of FBG as vibration sensor to nuclear plants, measurement systems were developed and tested. As a result, the FBGs could detect vibration even in gamma-ray environment. Moreover, vibration of a component around a cooling system at the YAYOI reactor could be detected successfully with FBG based sensors.

  4. Piezoelectric generator based on torsional modes for power harvesting from angular vibrations

    Institute of Scientific and Technical Information of China (English)

    CHEN Zi-guang; HU Yuan-tai; YANG Jia-shi

    2007-01-01

    Torsional vibration of a circular piezoelectric shell of polarized ceramics mounted on a rotationally vibrating base is analyzed. The shell is properly electroded and connected to a circuit such that an electric output is generated. The structure analyzed represents a piezoelectric generator for converting mechanical energy from angular vibrations to electrical energy. Analytical expressions and numerical results for the output voltage, current, power, efficiency and power density are given.

  5. The Spindle Unit of Machine Tool(Ⅱ)%机床的主轴单元(下)

    Institute of Scientific and Technical Information of China (English)

    张曙; 张柄生; 卫汉华

    2016-01-01

    通过回顾机床主轴发展历程,指出电主轴在高端数控机床的应用日益广泛。继而详尽地阐述了机床主轴单元的设计要点,包括轴承、润滑和冷却以及刀具接口等。接着对主轴的静动态和热性能分析以及建模仿真进行了全面介绍。最后指出主轴的工况监控、智能化和自适应控制是新一代电主轴的重要特征和未来发展趋势。%Reviewing the development of machine tool spindle, it points out that the application of motorized spindle in high-end CNC machine tools is becoming more and more widely. It shows the detail about the design key points of machine tool spindle unit such as bearing, lubrication, cooling and cutting tool interface. It illus-trates the static and dynamic and thermal performance analysis and modeling simulation for spindle unit, pre-sents the important characteristics and the future development trend in condition monitoring, intelligent and adaptive control ect.

  6. Evaluation of Bus Vibration Comfort Based on Passenger Crowdsourcing Mode

    Directory of Open Access Journals (Sweden)

    Hong Zhao

    2016-01-01

    Full Text Available Vibration comfort is an important factor affecting the quality of service (QoS of bus. In order to make people involved in supervising bus’s vibration comfort and improve passengers’ riding experience, a novel mode of passenger crowdsourcing is introduced. In this paper, comfort degree of bus vibration is calculated from bus’s vibration signals collected by passengers’ smartphones and sent through WiFi to the Boa web server which shows the vibration comfort on the LCD deployed in bus and maybe trigger alarm lamp when the vibration is beyond the threshold. Three challenges here have been overcome: firstly, space coordinate transformation algorithm is used to solve the constant drift of signals collected; secondly, a low-pass filter is designed to isolate gravity from signals real-timely via limited computing resources; thirdly, an embedded evaluation system is developed according to the calculation procedure specified by criterion ISO 2631-1997. Meanwhile, the model proposed is tested in a practical running environment, the vibration data in whole travel are recorded and analyzed offline. The results show that comfort degree of vibration obtained from the experimental system is identical with the truth, and this mode is proved to be effective.

  7. The Research on Collaborative Rules in the Collaborative Design of Machine Tool Based on the Assembling Constraints%组合机床协同设计中基于装配约束关系的协同规则研究

    Institute of Scientific and Technical Information of China (English)

    李月琴; 郭志强

    2011-01-01

    This paper described the fundamental structure of the aggregate machine, the constraints of the assembling interface, and the corresponding relationship of collaborative designer and products. From the angle of the matching of assembling interfaces, it analyzed the different constraint types of assembling parts in the process of designing the aggregate machine collaboratively. The paper investigated into the synergistic rules on interface based on the assembling constraints in three aspects, i.e. between general parts, between specific parts, and between general and specific parts. It hoped that different designers could co - operate smoothly under the rules to insure the development of new products.%文章简述了组合机床的基本结构、装配接口的约束特性及协同设计人员与产品之间的对应关系,并从装配接口匹配角度出发,对组合机床协同设计过程中各部件装配约束关系类型进行了探讨,研究了通用部件之间、专用部件之间以及专用部件和通用部件之间基于装配约束关系的接口协同规则,以期在此规则下,保证协同设计中各小组间密切合作的顺畅实现和产品开发的顺利进行.

  8. 基于模拟退火遗传算法优化BP网络的数控机床温度布点优化及热误差建模%CNC Machine Tool Temperature Measuring Point Optimization and Thermal Error Modeling Based on Stimulated Annealing and Optimized BP Network by Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    张景然; 沈牧文; 杨建国

    2014-01-01

    Optimization selection of the temperature measuring point is crucial during thermal error modeling. A method using correlation analysis was present to analyze the relationship between the spindle thermal drift and point temperature of measurement. The temperature distribution points of the optimal choice were achieved by finding a higher correlation measuring point of location. On basis of this, by using simulated annealing and genetic algorithm ( GSA) optimized BP neural network method, the thermal error model was established, and was verified by experiments. The results show optimized thermal error model can escape from local optimal and achieve global optimal solution. The resulting error model can fit values more closer to the actual measured error values. Based on simulated an⁃nealing genetic algorithm ( GSA) optimization, BP neural network model has higher accuracy and greater robustness than that of the traditional neural network model.%在热误差建模中,温度测点的优化选择至关重要。提出了运用相关性方法,分析测点温度与主轴热漂移之间的关系,找到相关性较高的测点位置,实现温度布点的优化选择。在此基础上采用模拟退火遗传算法( GSA)优化BP神经网络的方法建立热误差模型,并通过实验验证。结果表明:优化的热误差模型能够跳出局部最优而达到全局最优解,得到的误差模型拟合值更加接近实测误差值;基于GSA优化的BP网络模型较传统的神经网络模型有较高的精度及更强鲁棒性。

  9. Control of noise and structural vibration a MATLAB-based approach

    CERN Document Server

    Mao, Qibo

    2013-01-01

    Control of Noise and Structural Vibration presents a MATLAB®-based approach to solving the problems of undesirable noise generation and transmission by structures and of undesirable vibration within structures in response to environmental or operational forces. The fundamentals of acoustics, vibration and coupling between vibrating structures and the sound fields they generate are introduced including a discussion of the finite element method for vibration analysis. Following this, the treatment of sound and vibration control begins, illustrated by example systems such as beams, plates and double plate structures. Sensor and actuator placement is explained as is the idea of modal sensor–actuators. The design of appropriate feedback systems includes consideration of basic stability criteria and robust active structural acoustic control. Single and multi-mode positive position feedback (PPF) control systems are also described in the context of loudspeaker–duct model with non-collocated loudspeaker–microp...

  10. Features of energy distribution for blast vibration signals based on wavelet packet decomposition

    Institute of Scientific and Technical Information of China (English)

    LING Tong-hua; LI Xi-bing; DAI Ta-gen; PENG Zhen-bin

    2005-01-01

    Blast vibration analysis constitutes the foundation for studying the control of blasting vibration damage and provides the precondition of controlling blasting vibration. Based on the characteristics of short-time nonstationary random signal, the laws of energy distribution are investigated for blasting vibration signals in different blasting conditions by means of the wavelet packet analysis technique. The characteristics of wavelet transform and wavelet packet analysis are introduced. Then, blasting vibration signals of different blasting conditions are analysed by the wavelet packet analysis technique using MATLAB; energy distribution for different frequency bands is obtained. It is concluded that the energy distribution of blasting vibration signals varies with maximum decking charge,millisecond delay time and distances between explosion and the measuring point. The results show that the wavelet packet analysis method is an effective means for studying blasting seismic effect in its entirety, especially for constituting velocity-frequency criteria.

  11. A Tentative Study on Dynamics of a New Parallel NC Machine Tool with Long Travel, Large Rotating Angle and High Moving Speed

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In view of the structure of traditional five-coord in ate machine tool, the work-piece and machine tool often move along their respec tive guides simultaneously on the whole. In this kind of machine structure, the total mass of moving parts including work-pieces, fixtures, rotating table, wor king table and so on is often very large. Besides, the elastic reform of transmi ssion and the viscous friction force of the guide can not be ignored. As a resul t, the machine tool can not move with high velocity and...

  12. Physical property of basic unit and database in machine tool lightweight design%机床轻量化设计基本单元物理性能与数据库的研究

    Institute of Scientific and Technical Information of China (English)

    董惠敏; 邢俏芳; 王德胜; 姜怀胜; 王德伦; 申会鹏; 孙颖

    2012-01-01

    To provide the scientific basis for mac.hine tool structure lightweight design, the machine tool lightweight unit design technology is explored. The structure performance of panel-type unit is investigated. The basic unit database for the machine tool lightweight design is constructed. Through researching the internal structure feature of machine tool components in practical engineering application, the concept of lightweight panel-type unit is proposed. Seven kinds of plane-type basic units are abstracted, and the plane-type basic unit spectrum is established. Based on ANSYS finite element analysis method, the seven kinds of parametric physical models with plane-type basic unit are built. In the situation of basic unit with same dimension parameters or same mass, the static and dynamic performances of seven kinds of plane-type basic units are studied respectively. The static property of each kind of basic unit in pull, press, bend and twist, as well as the dynamic base frequency distribution rule are obtained, which provides the data sources for the machine tool lightweight database.%探讨机床轻量化单元设计技术,研究壁板类单元的结构性能,构建机床轻量化设计基本单元数据库,为机床支承件轻量化设计提供科学依据.通过研究实际工程应用中机床支承件的内部结构特征,提出机床轻量化壁板类单元概念,抽象出7种壁板类基本单元,建立壁板类基本单元型谱.基于AN-SYS有限元分析方法,建立7种壁板类基本单元的参数化物理模型.在基本单元尺度参数和质量相同情况下,分别研究了7种壁板类基本单元的静动态性能.得到各种基本单元的拉、压、弯、扭静态性能,以及动态基频分布规律,为机床轻量化数据库提供数据来源.

  13. Vibration control using a variable coil-based friction damper

    Science.gov (United States)

    Amjadian, Mohsen; Agrawal, Anil K.

    2017-04-01

    This paper is focused on the analytical model, design, and simulation of a variable coil-based friction damper (VCBFD) for vibration control of structures. The proposed VCBFD is composed of a soft ferromagnetic plate, made of a linear magnetic material, and two identical thick rectangular air-core coils connected in parallel, each one attached to the plate through a friction pad. The friction force is provided by a normal force produced through an attractive electromagnetic interaction between the air-core coils (ACs) and the soft ferromagnetic plate when sliding relative to each other. The magnitude of the normal force in the damper is varied by a semi-active controller that controls the command current passing through the ACs. To demonstrate the efficiency of the proposed VCBFD and its semi-active controller, it has been implemented on a two-degree-of-freedom (2DOF) base-isolated model subjected to the acceleration components of three records of strong earthquakes. The results show that the performance of the proposed VCBFD in its passive-on mode is overshadowed by the undesirable effects of stick-slip motion. However, the damper in its semi-active mode is more successful in not only reducing the displacement of the base-floor but also avoiding stick-slip motion, due to acting completely in its sliding phase.

  14. Rotor position and vibration control for aerospace flywheel energy storage devices and other vibration based devices

    Science.gov (United States)

    Alexander, B. X. S.

    Flywheel energy storage has distinct advantages over conventional energy storage methods such as electrochemical batteries. Because the energy density of a flywheel rotor increases quadratically with its speed, the foremost goal in flywheel design is to achieve sustainable high speeds of the rotor. Many issues exist with the flywheel rotor operation at high and varying speeds. A prominent problem is synchronous rotor vibration, which can drastically limit the sustainable rotor speed. In a set of projects, the novel Active Disturbance Rejection Control (ADRC) is applied to various problems of flywheel rotor operation. These applications include rotor levitation, steady state rotation at high speeds and accelerating operation. Several models such as the lumped mass model and distributed three-mass models have been analyzed. In each of these applications, the ADRC has been extended to cope with disturbance, noise, and control effort optimization; it also has been compared to various industry-standard controllers such as PID and PD/observer, and is proven to be superior. The control performance of the PID controller and the PD/observer currently used at NASA Glenn has been improved by as much as an order of magnitude. Due to the universality of the second order system, the results obtained in the rotor vibration problem can be straightforwardly extended to other vibrational systems, particularly, the MEMS gyroscope. Potential uses of a new nonlinear controller, which inherits the ease of use of the traditional PID, are also discussed.

  15. Chatter Suppression with Ultrasonic Elliptical Vibration Based on Energy Principle

    Institute of Scientific and Technical Information of China (English)

    MA Chun-xiang; E Shamoto; T Moriwaki

    2005-01-01

    A new method is proposed to suppress chatter, in which the ultrasonic elliptical vibration is added on the cutting tool edge. It results in the fact that the rake face of tool is separated from the chip and the direction of the frictional force between the rake face and the chip is reversed in each cycle of elliptical vibration cutting. The experimental investigations show that the chatter can be suppressed effectively by adding ultrasonic elliptical vibration on the cutting tool edge. In order to make clear the reason of chatter suppression, the mechanism of chatter suppression is analyzed theoretically from the viewpoint of energy.

  16. El Diseño Modular en el contexto del desarrollo de Máquinas Herramienta Reconfigurables. // Modular Design in the development of reconfigurable Machine Tools´ context.

    Directory of Open Access Journals (Sweden)

    R. Pérez Rodríguez

    2005-05-01

    Full Text Available Las tendencias actuales en los procesos de manufactura reflejan los cambios en las demandas de los clientes. En nuestrosdías, el mercado requiere inexorablemente de productos cada vez más personalizados, por lo que se tiende de unaproducción masiva hacia un tipo específico de producción, en menos tiempo y con menos costos de producción. Enrespuesta a esta necesidad, la nueva generación de máquinas herramienta debe de ser reconfigurable e inteligente. Lascaracterísticas principales de las Máquinas Reconfigurables e Inteligentes son la modularidad, convertibilidad, flexibilidady efectividad en los costos. Este artículo presenta un enfoque para el diseño modular de máquinas herramienta, basado en elportafolio de productos del constructor de máquinas. La metodología parte de un conjunto de requerimientos funcionalesdefinidos por el constructor de máquinas y ofrece una descripción de los posibles módulos que pueden ser desarrolladospara una determinada máquina herramienta reconfigurable.Palabras claves: Diseño modular, máquinas herramienta, reconfigurable, inteligente.___________________________________________________________________________Abstract.The manufacturing tendencies reflect the changes on the customer demands. Nowadays, the market is constantly requiringmore customized products, moving from mass production to “one-of-a-kind production” in less time with lower productioncosts. In response to this need, the next generation of machine tools should be reconfigurable and intelligent.Reconfigurability allows for the reduction of machine design lead time, machine set-up and ramp-up time. The principalcharacteristics of the Reconfigurable and Intelligent Machines are modularity, convertibility, flexibility and costeffectiveness.This paper presents an approach for the design of machine tools modules, based on the product portfolio ofthe machine tool builder. The methodology takes as input a set of functional requirements

  17. 面向XYZ-3RPS混联机床的后置处理算法%Post-processing algorithm oriented to XYZ-3RPS serial-parallel machine tool

    Institute of Scientific and Technical Information of China (English)

    王瑞; 张庆彪

    2016-01-01

    Aiming at eliminating the disadvantage in current post⁃processing system which cannot generate the CNC instruction for serial⁃parallel machine tool, post⁃processing algorithm, fit for this sort of processing device, was discussed based on XYZ⁃3RPS serial⁃parallel machine tool model. By the analysis of structure and post⁃processing process of the serial⁃parallel machine tool, the key algorithm of post⁃processing which includes interpolation algorithm for cutter bit data under Cartesian coordinates, the inverse solution under coordinate of machine tool and the interference checking algorithm were proposed. Meanwhile, some unqualified cutter bit positions were corrected and cutter location data files had been changed into machine tool driver files. Finally, the validity of the algorithm was verified by the processing experiments of vane and sphere.%针对现有的后置处理系统无法直接生成混联机床数控指令的问题,以XYZ -3RPS混联机床为模型,研究适合该加工装置的后置处理算法。对混联机床的结构以及后置处理过程进行分析,提出后置处理的关键算法:包括工件坐标系下刀位数据的双直线插补算法,机床坐标系下刀位数据的逆解算法以及混联装置的干涉检查算法,对不满足条件的刀位点进行相应的处理,实现将刀位数据文件转化为混联机床的驱动文件。叶片和球面加工实例验证了算法正确性和有效性。

  18. Study on the Reliability of CNC Machine Tools and Key Function Units%数控机床及其关键功能部件可靠性研究综述

    Institute of Scientific and Technical Information of China (English)

    李南; 卢晓红; 韩鹏卓; 武文毅

    2012-01-01

    At present, the reliability of CNC machine tools and their key function units has a significant gap with that of abroad. The reliability has been an important index to judge the performance of CNC machine tools and their key function units. Therefore, the study on their reliability is extremely urgent. Based on the large quantities of reliability researches of home and abroad, the paper summarizes the analysis and processing method of the failure data, the reliability evaluation methodology, the reliability growth technology and the reliability testing technology of CNC machine tools. Additionally, the paper explains the difference between the reliability study of the key function units of CNC machine tools and the complete machines. Finally, the paper presents the reliability research scheme and prospect of CNC machine tools and their key function units.%目前我国数控机床及其关键功能部件的可靠性水平与国外差距明显.而可靠性已经成为衡量数控机床及其关键功能部件性能好坏的重要指标之一,因此,数控机床及其关键功能部件可靠性研究迫在眉睫.文章在国内外大量相关可靠性研究的基础上,归纳总结了数控机床可靠性故障数据的分析及处理方法、可靠性评价方法、可靠性增长技术及可靠性试验技术;分析了数控机床关键功能部件可靠性研究与整机可靠性研究的不同之处,提出了数控机床整机及关键功能部件可靠性研究方案及展望.

  19. Micro-vibration-based slip detection in tactile force sensors.

    Science.gov (United States)

    Fernandez, Raul; Payo, Ismael; Vazquez, Andres S; Becedas, Jonathan

    2014-01-03

    Tactile sensing provides critical information, such as force, texture, shape or temperature, in manipulation tasks. In particular, tactile sensors traditionally used in robotics are emphasized in contact force determination for grasping control and object recognition. Nevertheless, slip detection is also crucial to successfully manipulate an object. Several approaches have appeared to detect slipping, the majority being a combination of complex sensors with complex algorithms. In this paper, we deal with simplicity, analyzing how a novel, but simple, algorithm, based on micro-vibration detection, can be used in a simple, but low-cost and durable, force sensor. We also analyze the results of using the same principle to detect slipping in other force sensors based on flexible parts. In particular, we show and compare the slip detection with: (i) a flexible finger, designed by the authors, acting as a force sensor; (ii) the finger torque sensor of a commercial robotic hand; (iii) a commercial six-axis force sensor mounted on the wrist of a robot; and (iv) a fingertip piezoresistive matrix sensor.

  20. Optimal Search Strategy of Robotic Assembly Based on Neural Vibration Learning

    Directory of Open Access Journals (Sweden)

    Lejla Banjanovic-Mehmedovic

    2011-01-01

    Full Text Available This paper presents implementation of optimal search strategy (OSS in verification of assembly process based on neural vibration learning. The application problem is the complex robot assembly of miniature parts in the example of mating the gears of one multistage planetary speed reducer. Assembly of tube over the planetary gears was noticed as the most difficult problem of overall assembly. The favourable influence of vibration and rotation movement on compensation of tolerance was also observed. With the proposed neural-network-based learning algorithm, it is possible to find extended scope of vibration state parameter. Using optimal search strategy based on minimal distance path between vibration parameter stage sets (amplitude and frequencies of robots gripe vibration and recovery parameter algorithm, we can improve the robot assembly behaviour, that is, allow the fastest possible way of mating. We have verified by using simulation programs that search strategy is suitable for the situation of unexpected events due to uncertainties.

  1. Vibration based Structural Health Monitoring of a composite T-beam

    NARCIS (Netherlands)

    Ooijevaar, T.H.; Loendersloot, R.; Warnet, L.L.; Boer, de A.; Akkerman, R.

    2010-01-01

    A vibration based damage identification method is investigated experimentally for a 2.5-dimensional composite structure. The dynamic response of an intact and a locally delaminated 16-layer unidirectional carbon fibre PEKK reinforced T-beam is considered. A force–vibration set-up, including a laser

  2. A piezoelectric six-DOF vibration energy harvester based on parallel mechanism: dynamic modeling, simulation, and experiment

    Science.gov (United States)

    Yuan, G.; Wang, D. H.

    2017-03-01

    Multi-directional and multi-degree-of-freedom (multi-DOF) vibration energy harvesting are attracting more and more research interest in recent years. In this paper, the principle of a piezoelectric six-DOF vibration energy harvester based on parallel mechanism is proposed to convert the energy of the six-DOF vibration to single-DOF vibrations of the limbs on the energy harvester and output voltages. The dynamic model of the piezoelectric six-DOF vibration energy harvester is established to estimate the vibrations of the limbs. On this basis, a Stewart-type piezoelectric six-DOF vibration energy harvester is developed and explored. In order to validate the established dynamic model and the analysis results, the simulation model of the Stewart-type piezoelectric six-DOF vibration energy harvester is built and tested with different vibration excitations by SimMechanics, and some preliminary experiments are carried out. The results show that the vibration of the limbs on the piezoelectric six-DOF vibration energy harvester can be estimated by the established dynamic model. The developed Stewart-type piezoelectric six-DOF vibration energy harvester can harvest the energy of multi-directional linear vibration and multi-axis rotating vibration with resonance frequencies of 17 Hz, 25 Hz, and 47 Hz. Moreover, the resonance frequencies of the developed piezoelectric six-DOF vibration energy harvester are not affected by the direction changing of the vibration excitation.

  3. Inertial Vibration Damping of a Flexible Base Manipulator

    National Research Council Canada - National Science Library

    GEORGE, Lynnane E; BOOK, Wayne J

    2003-01-01

    A rigid (micro) robot mounted serially to the tip of a long, flexible (macro) manipulator is often used to increase reach capability, but flexibility in the macromanipulator can make it susceptible to vibration...

  4. Analysis of micro vibration in gas film of aerostatic guide way based on molecule collision theory

    Directory of Open Access Journals (Sweden)

    Yang Shao Hua

    2016-01-01

    Full Text Available Micro vibration of the aerostatic guide way has a significant impact on its dynamic characteristics and stability, which limits the development of pneumatic component. High pressure gas molecules have been collided with the supporting surface and the internal surface of the throttle during the flow process. Variable impulse of the surfaces aside for the gas film are affected by the changes of impulse which formed irregular impact force in horizontal and vertical direction. Micro-vibration takes place based on the natural frequency of the system and its frequency doubling. In this paper, the vibration model was established to describe the dynamic characteristics of the gas film, and the formation mechanism of micro vibration in the film is defined. Through the simulation analysis and experimental comparison, formation mechanism of the micro vibration in the gas film is confirmed. It was proposed that the micro vibration of gas film can be produced no matter whether there is a gas chamber or not in the throttle. Under the same conditions, the micro vibration of the guide way with air chamber is greater than that without any chamber. The frequency points of the vibration peaks are almost the same, as well as the vibration pattern in the frequency domain.

  5. Health monitoring of aeronautical structures based on vibrations measurements

    Science.gov (United States)

    Bovio, Igor; Lecce, Leonardo

    2006-03-01

    Purpose of the paper is to present an innovative application inside the Non Destructive Testing field based on vibrations measurements, developed by the authors during the last three years, and already tested for analysing damage of many structural elements. The proposed new method is based on the acquisition and comparison of Frequency Response Functions (FRFs) of the monitored structure before and after an occurred damage. Structural damage modify the dynamical behaviour of the structure such as mass, stiffened and damping, and consequently the FRFs of the damaged structure in comparison with the FRFs of the sound structure, making possible to identify, to localize and quantify a structural damage. The activities, presented in the paper, mostly focused on a new FRFs processing technique based on the determining of a representative "Damage Index" for identifying and analysing damage both on real scale aeronautical structural components, like large-scale fuselage reinforced panels, and on aeronautical composite panels. Besides it has been carried out a dedicated neural network algorithm aiming at obtaining a "recognition-based learning"; this kind of learning methodology permits to train the neural network in order to let it recognises only "positive" examples discarding as a consequence the "negative" ones. Within the structural NDT a "positive" example means "healthy" state of the analysed structural component and, obviously, a "negative" one means a "damaged" or perturbed state. From an architectural point of view piezoceramic patches have been tested as actuators and sensors. Besides it has been used a laser-scanning vibrometer system to validate the behaviour of the piezoceramic patches.

  6. Vibration characteristic analysis method for the quartz microgyroscope based on the admittance circle

    Science.gov (United States)

    Wang, Haoxu; Dong, Peitao; Xie, Liqiang; Wu, Xuezhong

    2014-03-01

    The vibration characteristic analysis method for a quartz microgyroscope based on the admittance circle is reported in this paper. Admittance theory is introduced and the admittance circle principle is analysed to study the vibration characteristics of the quartz microgyroscope. The prototype gyroscope was fabricated by micro-electromechanical systems (MEMS) technology. The admittance and phase diagram of the work mode were obtained by vibration mode test systems. Then the admittance circle of the work mode was drawn, and the parameter identification of the transfer function between the voltage and current was completed to analyse the vibration characteristics. Therefore, the vibration characteristic analysis method based on the admittance circle can be used to build the transfer function of the quartz microgyroscope, which is helpful for the design of a high performance quartz microgyroscope.

  7. Vibration characteristic analysis method for the quartz microgyroscope based on the admittance circle

    Directory of Open Access Journals (Sweden)

    Haoxu Wang

    2014-02-01

    Full Text Available The vibration characteristic analysis method for a quartz microgyroscope based on the admittance circle is reported in this paper. Admittance theory is introduced and the admittance circle principle is analysed to study the vibration characteristics of the quartz microgyroscope. The prototype gyroscope was fabricated by micro-electromechanical systems (MEMS technology. The admittance and phase diagram of the work mode were obtained by vibration mode test systems. Then the admittance circle of the work mode was drawn, and the parameter identification of the transfer function between the voltage and current was completed to analyse the vibration characteristics. Therefore, the vibration characteristic analysis method based on the admittance circle can be used to build the transfer function of the quartz microgyroscope, which is helpful for the design of a high performance quartz microgyroscope.

  8. Active vibration control system of smart structures based on FOS and ER actuator

    Science.gov (United States)

    Leng, Jinsong; Asundi, A.

    1999-04-01

    An active vibration control system based on fiber optic sensor (FOS) and electrorheological (ER) actuator is established in this paper. A new intensity modulated fiber optic vibration sensor is developed following the face coupling theory. The experimental results show that this new type of intensity modulated fiber optic vibration sensor has higher sensitivity in measuring the vibration frequency. At the same time, experimental investigations are focused on evaluating the dynamic response characteristics of a beam fabricated with ER fluid. It is noted that the most significant change in the material properties of ER fluid is the change of material stiffness and damping which varies with the electric field intensity imposed upon the ER fluid. Finally, the structural vibration of the smart composite beam based on ER fluid, fiber optic sensor and piezoelectric transducer has been monitored and controlled actively utilizing a fuzzy-logic algorithm.

  9. An intelligent condition monitoring system for on-line classification of machine tool wear

    Energy Technology Data Exchange (ETDEWEB)

    Fu Pan; Hope, A.D.; Javed, M. [Systems Engineering Faculty, Southampton Institute (United Kingdom)

    1997-12-31

    The development of intelligent tool condition monitoring systems is a necessary requirement for successful automation of manufacturing processes. This presentation introduces a tool wear monitoring system for milling operations. The system utilizes power, force, acoustic emission and vibration sensors to monitor tool condition comprehensively. Features relevant to tool wear are drawn from time and frequency domain signals and a fuzzy pattern recognition technique is applied to combine the multisensor information and provide reliable classification results of tool wear states. (orig.) 10 refs.

  10. Microgravity Vibration Isolation System Based on Parallel Kinematic Communications

    Science.gov (United States)

    Russkin, Alexander; Postojuk, Nikolay

    The paper is devoted to the construction of an active vibration isolation system of experimental and technological equipment operating in microgravity conditions. Space experiments associated with obtaining ultrapure materials are required the residual level of microgravity vibration from mmug to mg at the frequency range from 0.01 Hz to 100 Hz in the experiment area. This residual level of microgravity vibration is difficult to achieve by conventional passive protection systems. To date the different types of active vibration isolation systems are constructed, such as STABLE, ARIS, MIM, g-LIMIT and MVIS, but their characteristics and geometrical parameters do not always satisfy the given technological requirements. In this paper, the mechanism with parallel kinematic constraints (MPKS) is proposed for constructing microgravity active vibration isolation system, which provides protection against vibrations in six degrees of freedom and can be scaled depending on the specific tasks. MPKS distinguishing feature is the presence of closed kinematic chain, which provide high rigidity of the structure, reduce the mass of moving parts and reduce the load on the actuator. As a result, this increases the dynamics and positioning accuracy MPKS. The proposed version of microgravity vibration isolation system consists of two main parts: the electromechanical assembly and control unit. The main specifications for the constituent parts of the system are defined. A comparative analysis of different types of actuators and sensors for electromechanical assembly is carried out. The appropriate components to provide the desired specifications are selected. There are proposed to use piezoelectric motors as actuators in electromechanical assembly. Mathematical models of MPKS with six degrees of freedom and control system are considered. The structure of the control system and controller type is selected. A mathematical model of proposed microgravity vibration isolation system is

  11. Airflow energy harvesters of metal-based PZT thin films by self-excited vibration

    Science.gov (United States)

    Suwa, E.; Tsujiura, Y.; Kurokawa, F.; Hida, H.; Kanno, I.

    2014-11-01

    We developed self-excited vibration energy harvesters of Pb(Zr,Ti)O3 (PZT) thin films using airflow. To enhance the self-excited vibration, we used 30-μm-thick stainless steel (SS304) foils as base cantilevers on which PZT thin films were deposited by rf-magnetron sputtering. To compensate for the initial bending of PZT/SS304 unimorph cantilever due to the thermal stress, we deposited counter PZT thin films on the back of the SS304 cantilever. We evaluated power-generation performance and vibration mode of the energy harvester in the airflow. When the angle of attack (AOA) was 20° to 30°, large vibration was generated at wind speeds over 8 m/s. By FFT analysis, we confirmed that stable self-excited vibration was generated. At the AOA of 30°, the output power reached 19 μW at wind speeds of 12 m/s.

  12. The influence of mechanical vibrations on microstructure of Ni-based thermally sprayed-fused coatings

    Directory of Open Access Journals (Sweden)

    Jelena ŠKAMAT

    2013-12-01

    Full Text Available The influence of mechanical vibrations on microstructure and properties of Ni-based thermally sprayed and fused coatings deposited on a steel substrate has been studied. Self-fluxing powder with about 73% Ni was used as a sprayed material. As-sprayed coatings were refused using conventional flame technique and with introducing of mechanical vibrations. In result coatings with quite complicated microstructure were obtained. During investigation of coatings by different methods it was found that vibratory treatment really influences the solidified microstructure. It was found that vibrations promote densimetric movement of hard particles up - towards a surface with forming of thicker so-called “hard-inclusions-free” layer near interface. Some tendency was noted that coatings, remelted under vibrations, showed better corrosion and high-temperature oxidation resistance in comparison with coatings created without vibrational treatment during solidification.

  13. Modeling for IFOG Vibration Error Based on the Strain Distribution of Quadrupolar Fiber Coil.

    Science.gov (United States)

    Gao, Zhongxing; Zhang, Yonggang; Zhang, Yunhao

    2016-07-21

    Improving the performance of interferometric fiber optic gyroscope (IFOG) in harsh environment, especially in vibrational environment, is necessary for its practical applications. This paper presents a mathematical model for IFOG to theoretically compute the short-term rate errors caused by mechanical vibration. The computational procedures are mainly based on the strain distribution of quadrupolar fiber coil measured by stress analyzer. The definition of asymmetry of strain distribution (ASD) is given in the paper to evaluate the winding quality of the coil. The established model reveals that the high ASD and the variable fiber elastic modulus in large strain situation are two dominant reasons that give rise to nonreciprocity phase shift in IFOG under vibration. Furthermore, theoretical analysis and computational results indicate that vibration errors of both open-loop and closed-loop IFOG increase with the raise of vibrational amplitude, vibrational frequency and ASD. Finally, an estimation of vibration-induced IFOG errors in aircraft is done according to the proposed model. Our work is meaningful in designing IFOG coils to achieve a better anti-vibration performance.

  14. Modeling for IFOG Vibration Error Based on the Strain Distribution of Quadrupolar Fiber Coil

    Directory of Open Access Journals (Sweden)

    Zhongxing Gao

    2016-07-01

    Full Text Available Improving the performance of interferometric fiber optic gyroscope (IFOG in harsh environment, especially in vibrational environment, is necessary for its practical applications. This paper presents a mathematical model for IFOG to theoretically compute the short-term rate errors caused by mechanical vibration. The computational procedures are mainly based on the strain distribution of quadrupolar fiber coil measured by stress analyzer. The definition of asymmetry of strain distribution (ASD is given in the paper to evaluate the winding quality of the coil. The established model reveals that the high ASD and the variable fiber elastic modulus in large strain situation are two dominant reasons that give rise to nonreciprocity phase shift in IFOG under vibration. Furthermore, theoretical analysis and computational results indicate that vibration errors of both open-loop and closed-loop IFOG increase with the raise of vibrational amplitude, vibrational frequency and ASD. Finally, an estimation of vibration-induced IFOG errors in aircraft is done according to the proposed model. Our work is meaningful in designing IFOG coils to achieve a better anti-vibration performance.

  15. Vibration Control of a Semiactive Vehicle Suspension System Based on Extended State Observer Techniques

    Directory of Open Access Journals (Sweden)

    Ze Zhang

    2014-01-01

    Full Text Available A feedback control method based on an extended state observer (ESO method is implemented to vibration reduction in a typical semiactive suspension (SAS system using a magnetorheological (MR damper as actuator. By considering the dynamic equations of the SAS system and the MR damper model, an active disturbance rejection control (ADRC is designed based on the ESO. Numerical simulation and real-time experiments are carried out with similar vibration disturbances. Both the simulation and experimental results illustrate the effectiveness of the proposed controller in vibration suppression for a SAS system.

  16. Low-cost vibration sensor based on dual fiber Bragg gratings and light intensity measurement.

    Science.gov (United States)

    Gao, Xueqing; Wang, Yongjiao; Yuan, Bo; Yuan, Yinquan; Dai, Yawen; Xu, Gang

    2013-09-20

    A vibration monitoring system based on light intensity measurement has been constructed, and the designed accelerometer is based on steel cantilever frame and dual fiber Bragg gratings (FBGs). By using numerical simulations for the dual FBGs, the dependence relationship of the area of main lobes on the difference of initial central wavelengths is obtained and the most optimal choice for the initial value and the vibration amplitude of the difference of central wavelengths of two FBGs is suggested. The vibration monitoring experiments are finished, and the measured data are identical to the simulated results.

  17. Enhanced ground-based vibration testing for aerodynamic environments

    Science.gov (United States)

    Daborn, P. M.; Ind, P. R.; Ewins, D. J.

    2014-12-01

    Typical methods of replicating aerodynamic environments in the laboratory are generally poor. A structure which flies "freely" in its normal operating environment, excited over its entire external surface by aerodynamic forces and in all directions simultaneously, is then subjected to a vibration test in the laboratory whilst rigidly attached to a high impedance shaker and excited by forces applied through a few attachment points and in one direction only. The two environments could hardly be more different. The majority of vibration testing is carried out at commercial establishments and it is understandable that little has been published which demonstrates the limitations with the status quo. The primary objective of this research is to do just that with a view to identifying significant improvements in vibration testing in light of modern technology. In this paper, case studies are presented which highlight some of the limitations with typical vibration tests showing that they can lead to significant overtests, sometimes by many orders of magnitude, with the level of overtest varying considerably across a wide range of frequencies. This research shows that substantial benefits can be gained by "freely" suspending the structure in the laboratory and exciting it with a relatively small number of electrodynamic shakers using Multi-Input-Multi-Output (MIMO) control technology. The shaker configuration can be designed to excite the modes within the bandwidth utilising the inherent amplification of the resonances to achieve the desired response levels. This free-free MIMO vibration test approach is shown to result in substantial benefits that include extremely good replication of the aerodynamic environment and significant savings in time as all axes are excited simultaneously instead of the sequential X, Y and Z testing required with traditional vibration tests. In addition, substantial cost savings can be achieved by replacing some expensive large shaker systems

  18. Grey Theory Based Vibration Prediction for Steam Turbines

    Institute of Scientific and Technical Information of China (English)

    LIANG Lei; SU Leitao; FENG Yongxin; JIANG Dongxiang

    2012-01-01

    The Mechanism of grey prediction method and its application advantages in safety prediction were described.This method was used to predict the vibration amplitude within the coming 6 hours for a steam turbine.Moreover,the prediction results were examined using correlation degree and posterior error.Results indicated that,this grey prediction method had small posterior error and got a grade Ⅰ accuracy.We can foreknow the variation trend of vibration amplitude of the steam turbine through this method,so as to take timely countermeasures.Therefore,the operation safety of the power unit was improved.

  19. The High Precision Vibration Signal Data Acquisition System Based on the STM32

    National Research Council Canada - National Science Library

    Zhu Hui-Ling; Zhu Xin-Yin

    2014-01-01

    ... changes in cable resistance. Therefore, this paper proposed a high precision vibration signal acquisition with storage function based on STM32 microcontroller in order to promote safety in engineering construction...

  20. Vibration based structural health monitoring in fibre reinforced composites employing the modal strain energy method

    NARCIS (Netherlands)

    Ooijevaar, T.H.; Loendersloot, R.; Warnet, L.L.; Boer, de A.; Akkerman, R.

    2009-01-01

    The feasibility of a vibration based damage identification method is shown. The Modal Strain Energy method is applied to a T-joint structure. Both finite element analysis and experimental validation of an undamaged and delaminated structure are presented.

  1. Generated spiral bevel gears: Optimal machine-tool settings and tooth contact analysis

    Science.gov (United States)

    Litvin, F. L.; Tsung, W. J.; Coy, J. J.; Heine, C.

    1985-01-01

    Geometry and kinematic errors were studied for Gleason generated spiral bevel gears. A new method was devised for choosing optimal machine settings. These settings provide zero kinematic errors and an improved bearing contact. The kinematic errors are a major source of noise and vibration in spiral bevel gears. The improved bearing contact gives improved conditions for lubrication. A computer program for tooth contact analysis was developed, and thereby the new generation process was confirmed. The new process is governed by the requirement that during the generation process there is directional constancy of the common normal of the contacting surfaces for generator and generated surfaces of pinion and gear.

  2. Generated spiral bevel gears - Optimal machine-tool settings and tooth contact analysis

    Science.gov (United States)

    Litvin, F. L.; Tsung, W.-J.; Coy, J. J.; Heine, C.

    1985-01-01

    Geometry and kinematic errors were studied for Gleason generated spiral bevel gears. A new method was devised for choosing optimal machine settings. These settings provide zero kinematic errors and an improved bearing contact. The kinematic errors are a major source of noise and vibration in spiral bevel gears. The improved bearing contact gives improved conditions for lubrication. A computer program for tooth contact analysis was developed, and thereby the new generation process was confirmed. The new process is governed by the requirement that during the generation process there is directional constancy of the common normal of the contacting surfaces for generator and generated surfaces of pinion and gear.

  3. Capacitance-Based Frequency Adjustment of Micro Piezoelectric Vibration Generator

    Directory of Open Access Journals (Sweden)

    Xinhua Mao

    2014-01-01

    Full Text Available Micro piezoelectric vibration generator has a wide application in the field of microelectronics. Its natural frequency is unchanged after being manufactured. However, resonance cannot occur when the natural frequencies of a piezoelectric generator and the source of vibration frequency are not consistent. Output voltage of the piezoelectric generator will sharply decline. It cannot normally supply power for electronic devices. In order to make the natural frequency of the generator approach the frequency of vibration source, the capacitance FM technology is adopted in this paper. Different capacitance FM schemes are designed by different locations of the adjustment layer. The corresponding capacitance FM models have been established. Characteristic and effect of the capacitance FM have been simulated by the FM model. Experimental results show that the natural frequency of the generator could vary from 46.5 Hz to 42.4 Hz when the bypass capacitance value increases from 0 nF to 30 nF. The natural frequency of a piezoelectric vibration generator could be continuously adjusted by this method.

  4. Discussion of programming of CNC machine tool%数控机床程序编制探讨

    Institute of Scientific and Technical Information of China (English)

    徐晓东

    2013-01-01

      手工编程是指由人工来完成数控机床程序编制各个阶段的工作,这种方法比较简单,易掌握,适应性大,因而目前仍被广泛的应用与各类数控机床的编程。自动编程又称为计算机辅助编程,自动编程使得一些计算繁琐、手工编程困难或无法编出的程序能够顺利地完成。%Manual programming completes any stage of programming of CNC machine tool by manual, this method is relatively simple and easy to master and greatly adaptable and therefore is still widely used for programming of CNC ma-chine tool . Automatic programming also known as computer-aided programming that successfully completes some cocka-mamie calculations and the program that is difficult or unable to complete by manual programming.

  5. Thermal Error Modeling Method with the Jamming of Temperature-Sensitive Points' Volatility on CNC Machine Tools

    Science.gov (United States)

    MIAO, Enming; LIU, Yi; XU, Jianguo; LIU, Hui

    2017-03-01

    Aiming at the deficiency of the robustness of thermal error compensation models of CNC machine tools, the mechanism of improving the models' robustness is studied by regarding the Leaderway-V450 machining center as the object. Through the analysis of actual spindle air cutting experimental data on Leaderway-V450 machine, it is found that the temperature-sensitive points used for modeling is volatility, and this volatility directly leads to large changes on the collinear degree among modeling independent variables. Thus, the forecasting accuracy of multivariate regression model is severely affected, and the forecasting robustness becomes poor too. To overcome this effect, a modeling method of establishing thermal error models by using single temperature variable under the jamming of temperature-sensitive points' volatility is put forward. According to the actual data of thermal error measured in different seasons, it is proved that the single temperature variable model can reduce the loss of forecasting accuracy resulted from the volatility of temperature-sensitive points, especially for the prediction of cross quarter data, the improvement of forecasting accuracy is about 5 μm or more. The purpose that improving the robustness of the thermal error models is realized, which can provide a reference for selecting the modeling independent variable in the application of thermal error compensation of CNC machine tools.

  6. Customized DSP-based vibration measurement for wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    LaWhite, N.E.; Cohn, K.E. [Second Wind Inc., Somerville, MA (United States)

    1996-12-31

    As part of its Advanced Distributed Monitoring System (ADMS) project funded by NREL, Second Wind Inc. is developing a new vibration measurement system for use with wind turbines. The system uses low-cost accelerometers originally designed for automobile airbag crash-detection coupled with new software executed on a Digital Signal Processor (DSP) device. The system is envisioned as a means to monitor the mechanical {open_quotes}health{close_quotes} of the wind turbine over its lifetime. In addition the system holds promise as a customized emergency vibration detector. The two goals are very different and it is expected that different software programs will be executed for each function. While a fast Fourier transform (FFT) signature under given operating conditions can yield much information regarding turbine condition, the sampling period and processing requirements make it inappropriate for emergency condition monitoring. This paper briefly reviews the development of prototype DSP and accelerometer hardware. More importantly, it reviews our work to design prototype vibration alarm filters. Two-axis accelerometer test data from the experimental FloWind vertical axis wind turbine is analyzed and used as a development guide. Two levels of signal processing are considered. The first uses narrow band pre-processing filters at key fundamental frequencies such as the 1P, 2P and 3P. The total vibration energy in each frequency band is calculated and evaluated as a possible alarm trigger. In the second level of signal processing, the total vibration energy in each frequency band is further decomposed using the two-axis directional information. Directional statistics are calculated to differentiate between linear translations and circular translations. After analyzing the acceleration statistics for normal and unusual operating conditions, the acceleration processing system described could be used in automatic early detection of fault conditions. 9 figs.

  7. 吸振器底座对减振效果的影响%Study on Influence of Vibration Absorber' s Base on Its Vibration Attenuation Effect

    Institute of Scientific and Technical Information of China (English)

    徐振邦

    2011-01-01

    In reality, all vibration absorbers have bases. When the vibration absorber is fixed to a flexible base, the base will affect its vibration attenuation effect. Aiming at this problem, simulation researches are carried out with the power flow method in this paper. A mathematical model of the system composed of the vibration absorber with a base and coupled with an ends-fixed beam is established. With this model, the vibration attenuation effects of the vibration absorbers fixed at different positions of the beam are simulated, and the influence of the base size on the vibration attenuation effect is analyzed. On the basis, the vibration attenuation effect with double vibration absorbers attached is compared with that with a single vibration absorber attached. The results show that the vibration attenuation effect of the vibration absorber can be improved effectively by optimizing its base and installation condition. This work provides guidance for the engineering application of the vibration absorbers.%实际使用的吸振器都具有一定尺寸的安装底座.当吸振器安装于柔性主系统时,底座将影响吸振器的减振效果.针对此问题,利用功率流方法进行仿真研究.建立有底座吸振器和两端固支梁主系统耦合的数学模型.利用该模型对吸振器安装在梁上三个不同位置的情况进行仿真研究,并分析底座尺寸的影响,在此基础上比较两个吸振器和单个吸振器的减振效果.研究结果表明,通过优化吸振器的底座和安装方式能够有效地改善吸振器的减振性能.这为吸振器的工程应用提供一定的参考.

  8. Pulse-induced acoustoelectric vibrations in surface-gated GaAs-based quantum devices

    Science.gov (United States)

    Rahman, S.; Stace, T. M.; Langtangen, H. P.; Kataoka, M.; Barnes, C. H. W.

    2007-05-01

    We present the results of a numerical investigation which show the excitation of acoustoelectric modes of vibration in GaAs-based heterostructures due to sharp nanosecond electric-field pulses applied across surface gates. In particular, we show that the pulses applied in quantum information processing applications are capable of exciting acoustoelectric modes of vibration including surface acoustic modes which propagate for distances greater than conventional device dimensions. We show that the pulse-induced acoustoelectric vibrations are capable of inducing significant undesired perturbations to the evolution of quantum systems.

  9. Electrical Interface for a Self-Powered MR Damper-Based Vibration Reduction System

    Directory of Open Access Journals (Sweden)

    Jastrzębski Łukasz

    2016-09-01

    Full Text Available The study investigates the behaviour of an electrical interface incorporated in a MR damper-based vibration reduction system powered with energy recovered from vibration. The interface, comprising the R, L and C elements, is connected in between the coil in an electromagnetic electric generator and the control coil in the MR damper and its function is to convert the output voltage from the generator. The interface model was formulated and computer simulations were performed to find out how the parameters of the interface should influence the frequency responses of the vibration reduction system.

  10. Vibration sensing using a tapered bend-insensitive fiber based Mach-Zehnder interferometer.

    Science.gov (United States)

    Xu, Yanping; Lu, Ping; Qin, Zengguang; Harris, Jeremie; Baset, Farhana; Lu, Ping; Bhardwaj, Vedula Ravi; Bao, Xiaoyi

    2013-02-11

    In this study, a novel fiber-optic sensor consisting of a tapered bend-insensitive fiber based Mach-Zehnder interferometer is presented to realize damped and continuous vibration measurement. The double cladding structure and the central coating region of the in-fiber interferometer ensure an enhanced mechanical strength, reduced external disturbance, and a more uniform spectrum. A damped vibration frequency range of 29-60 Hz as well as continuous vibration disturbances ranging from 1 Hz up to 500 kHz are successfully demonstrated.

  11. Development of a multi-point polarization-based vibration sensor.

    Science.gov (United States)

    Linze, Nicolas; Tihon, Pierre; Verlinden, Olivier; Mégret, Patrice; Wuilpart, Marc

    2013-03-11

    In this paper we propose a novel kind of multi-point vibration sensor based on the polarization properties of light. Its principle relies on the combination of mechanical transducers with fiber Bragg gratings. When subject to vibrations, the mechanical transducers induce birefringence variations within the fiber and in turn modify the state of polarization, which appears as a power variation after going through a polarizer. The FBGs reflect light from different positions of the sensing fiber and provide wavelength multiplexing. We show that this sensor can provide the vibration frequencies in a quasi-distributed manner.

  12. A MEMS-Based Piezoelectric Power Generator for Low Frequency Vibration Energy Harvesting

    Institute of Scientific and Technical Information of China (English)

    FANG Hua-Bin; LIU Jing-Quan; XU Zheng-Yi; DONG Lu; CHEN Di; CAI Bing-Chu; LIU Yue

    2006-01-01

    @@ A novel power generator has been achieved to convert vibration to electrical energy via the piezoelectric effect. The generator obtained by micro fabrication process mainly consists of silicon based frame and composite cantilever.The prototype tested at resonant vibration generates 1.15 μ W of effective power to a 20.4-kΩ resistance load. The potential of this work is to offer miniaturization solutions for power generators, and with the proposed method the ambient ubiquitous vibration can be harvested effectively as endless energy source to form an integrated self-powering system.

  13. A Vibration-Based Strategy for Health Monitoring of Offshore Pipelines’ Girth-Welds

    Directory of Open Access Journals (Sweden)

    Pejman Razi

    2014-09-01

    Full Text Available This study presents numerical simulations and experimental verification of a vibration-based damage detection technique. Health monitoring of a submerged pipe’s girth-weld against an advancing notch is attempted. Piezoelectric transducers are bonded on the pipe for sensing or actuation purposes. Vibration of the pipe is excited by two means: (i an impulsive force; (ii using one of the piezoelectric transducers as an actuator to propagate chirp waves into the pipe. The methodology adopts the empirical mode decomposition (EMD, which processes vibration data to establish energy-based damage indices. The results obtained from both the numerical and experimental studies confirm the integrity of the approach in identifying the existence, and progression of the advancing notch. The study also discusses and compares the performance of the two vibration excitation means in damage detection.

  14. Vibration Analysis of Aeroengine Blisk Structure Based on a Prestressed CMS Super-Element Method

    Directory of Open Access Journals (Sweden)

    Zhijun Li

    2016-01-01

    Full Text Available For vibration analysis of aeroengine blisk structure, a prestressed component modal synthesis (CMS super-element method is put forward with the fixed interface prestressing and free interface super-element approach. Based on this method, natural vibration characteristics of blisk structure are calculated at different modal truncation numbers. Comparing with the accurate result of global method, the selection principle of modal truncation number is obtained which affects the accuracy of prestressed CMS super-element method. Vibration response of two-stage blisk structure is calculated by this method, and the effects of different blade aspect ratios have been discussed on vibration characteristics. The results show that prestressed CMS super-element method is in the high accuracy and efficiency on blisk vibration analysis. Resonant frequencies in vibration response are nearly the same between the first-stage blisk and the second-stage blisk, and they are both approximately located in the range 588 Hz–599 Hz. The maximum displacement and dynamic stress are at blade tip and root of the first-stage blisk, respectively. Blade aspect ratio is a key factor of blisk vibration; the effects of blade aspect ratio on natural frequencies are different in the conditions of fixed width and fixed length. This research provides the theoretical basis for dynamic design of aeroengine compressor rotor system.

  15. FPGA-Based Fused Smart Sensor for Dynamic and Vibration Parameter Extraction in Industrial Robot Links

    OpenAIRE

    Rene de Jesus Romero-Troncoso; Gilberto Herrera-Ruiz; Roque Alfredo Osornio-Rios; Luis Morales-Velazquez; Carlos Rodriguez-Donate

    2010-01-01

    Intelligent robotics demands the integration of smart sensors that allow the controller to efficiently measure physical quantities. Industrial manipulator robots require a constant monitoring of several parameters such as motion dynamics, inclination, and vibration. This work presents a novel smart sensor to estimate motion dynamics, inclination, and vibration parameters on industrial manipulator robot links based on two primary sensors: an encoder and a triaxial accelerometer. The proposed s...

  16. Variational principles for transversely vibrating multiwalled carbon nanotubes based on nonlocal Euler-Bernoulli beam model.

    Science.gov (United States)

    Adali, Sarp

    2009-05-01

    Variational principles are derived for multiwalled carbon nanotubes undergoing vibrations. Derivations are based on the continuum modeling with the Euler-Bernoulli beam representing the nanotubes and small scale effects taken into account via the nonlocal elastic theory. Hamilton's principle for multiwalled nanotubes is given and Rayleigh's quotient for the frequencies is derived for nanotubes undergoing free vibrations. Natural and geometric boundary conditions are derived which lead to a set of coupled boundary conditions due to nonlocal effects.

  17. Vibration control of flexible structures via electrorheological-fluid-based dampers

    Science.gov (United States)

    Wang, Kon-Well; Kim, Y. S.; Lee, H. S.; Shea, D. B.

    1993-09-01

    The semi-active control approach has been recognized to be effective for vibration suppression of flexible structures. The electrorheological (ER) fluid-based device is a good candidate for such applications. In this research, a new control law is developed to maximize the damping effect of ER dampers for structural vibration suppression under actuator constraints and viscous-frictional-combined damping. Both numerical simulations and experimental work have been carried out to evaluate and validate the theoretical predictions.

  18. Distributed optical fiber vibration sensor based on spectrum analysis of Polarization-OTDR system.

    Science.gov (United States)

    Zhang, Ziyi; Bao, Xiaoyi

    2008-07-07

    A fully distributed optical fiber vibration sensor is demonstrated based on spectrum analysis of Polarization-OTDR system. Without performing any data averaging, vibration disturbances up to 5 kHz is successfully demonstrated in a 1km fiber link with 10m spatial resolution. The FFT is performed at each spatial resolution; the relation of the disturbance at each frequency component versus location allows detection of multiple events simultaneously with different and the same frequency components.

  19. The Design of the High Accuracy and Supported Multitasks Numerically-Controlled Machine Tool Control Cystem%支持多任务的高精度数控机床控制系统设计

    Institute of Scientific and Technical Information of China (English)

    贾文

    2011-01-01

    This paper Has researched the realization plan of numerically-controlled machine tool software and hardware deeply, has given the microprocessor and motion control chip types.has researched the multitasks scheduling strategy with emphsis,has given the realtime task scheduling plan based on the RT-Linux core, which solved multitasks scheduling while guaranteed the partial duty timeliness. In addition, has studied increasing the working accuracy the method in the numerically-controlled machine tool processing process, has analyzed the data transmission flow influenced the precision in working process, has designed data processing flow that can enhance the numerically-controlled machine tool working accuracy.%深入研究了数控机床软硬件实现方案,给出了机床数控系统中微处理器和运动控制芯片的型号.重点对数控系统中多任务的调度策略进行研究,给出了基于RT-Linux内核的任务调度方案,在解决多任务调度的同时保证了部分任务的实时性.除此之外,研究在数控机床加工过程中提高加工精度的方法,分析了工件加工过程中,对精度有影响的加工数据的传递过程,设计了有助于提高加工精度的机床数据处理过程.

  20. Management Maintenance of CNC Machine Tools%浅谈教学用数控机床的管理与维护

    Institute of Scientific and Technical Information of China (English)

    黄金波

    2011-01-01

    In this paper,the working characteristics of CNC machine tools for teaching,management,maintenance and repair and other aspects,that the teaching performance of CNC machine tools used to play good or bad depends on the management and maintenance personnel,quality and operational skills,made from different aspects and perspectives strengthen the management of CNC machine tools,targeted to improve and perfect maintenance and repair of CNC machine tools mechanisms.CNC machine tools to ensure long-term safe and stable operation,better for the teaching service.%本文从教学用数控机床工作特点、管理、维护和保养等方面入手,指出了教学用数控机床效能发挥的好坏取决于管理使用和维修人员的素质和操作技能,提出了要从不同方面和角度加强数控机床的管理,有针对性的完善和健全数控机床的维护和保养机制。确保数控机床长期安全平稳运行,更好的为教学服务。

  1. 全生命周期下的机床清洁度%Cleanliness of machine tool in its whole life cycle

    Institute of Scientific and Technical Information of China (English)

    馬家(騄); 龙兴元

    2013-01-01

    在中国机床工业从机床制造业大国向机床制造业强国迈进的时刻,有必要将清洁度扩展到全生命周期之中,应该认识到机床清洁度是机床的固有属性.讨论了清洁度的概念、分级及检验,获得了清洁度的两个不同阶段的相应方法:清洗和防护.还讨论了机床清洗几个重要概念及防尘密封在机床设计中的重要性.%At the critical moment while China machine tool industry is growing from a great nation to a powerful nation, it is necessary to make an application of extending the cleanliness into its whole life cycle of machine tools, not only manufacturing but also working. It should also be known that cleanliness is a built -in attribute of machine tools. In this paper, the author describes the concept and classification of cleanliness and its inspection, the methods for getting cleanliness in different steps, as well as cleaning and protecting. In addition, several important concepts of machine tool cleaning and the importance of dust-prooving and sealing in machine tool design are also discussed.

  2. Application and Development Direction of Machine Tool Fixture%机床夹具的应用与发展方向

    Institute of Scientific and Technical Information of China (English)

    田晓光; 刘丽娜

    2016-01-01

    As is known to all,the fixture has been compared to the machine tool“hand”,Machine tool fixture plays an impor-tant role in the machine tool.This article predict the trend of the development of machine tool fixturefrom the present situation of the application of machine tool fixture and processing manufacturing industry for manufacturing demands and puts forward the fu-ture machine tool fixture moving toward economic and general direction of high precision,high efficiency and module.%众所周知,夹具被比喻为机床的“手”,机床夹具在机床中起着重要的作用。文章从机床夹具的应用现状和加工制造行业对工件制造的要求来看机床夹具的发展趋势,提出了机床夹具未来正朝着高效、高精、组合、模块、通用、经济的方向发展。

  3. An autonomous multisensor in situ metrology system for enabling high dynamic range measurement of 3D surfaces on precision machine tools

    Science.gov (United States)

    Liu, Samuel M. Y.; Cheung, Benny C. F.; Whitehouse, David; Cheng, Ching-Hsiang

    2016-11-01

    An in situ measurement is of prime importance when trying to maintain the position of the workpiece for further compensation processes in order to improve the accuracy and efficiency of the precision machining of three dimensional (3D) surfaces. However, the coordinates of most of the machine tools with closed machine interfaces and control system are not accessible for users, which make it difficult to use the motion axes of the machine tool for in situ measurements. This paper presents an autonomous multisensor in situ metrology system for enabling high dynamic range measurement of 3D surfaces on precision machine tools. It makes use of a designed tool path and an additional motion sensor to assist the registration of time-space data for the position estimation of a 2D laser scanner which measures the surface with a high lateral resolution and large area without the need to interface with the machine tool system. A prototype system was built and integrated into an ultra-precision polishing machine. Experimental results show that it measures the 3D surfaces with high resolution, high repeatability, and large measurement range. The system not only improves the efficiency and accuracy of the precision machining process but also extends the capability of machine tools.

  4. Research on Properties of Machine Tool Table with Truss Structure%桁架结构工作台的性能研究

    Institute of Scientific and Technical Information of China (English)

    毛志云; 高东强; 黎忠炎

    2011-01-01

    利用SolidWorks软件实现了桁架结构工作台及加强筋板工作台的三维建模,将模型导入到ANSYS Workbench软件中.用ANSYS Workbench软件对2工作台的静态、模态、谐响应进行有限元分析,得出桁架结构工作台静、动态性能优于加强筋板工作台的特点,为机床的优化设计和再制造设计打下了基础.%The 3D solid model of the machine tool table with truss structure and the machine tool table with stiffener are created with SolidWorks software, then the models are leaded to ANSYS Workbench software. Carrying out finite element analysis the static analysis, modal analysis and harmonic response of the two machine tool table are obtained with ANSYS Workbench software respectively. The results show that the static and dynamic properties of the machine tool table with truss structure are better than that of the machine tool table with stiffener which lay the foundation of optimized design and remanufacturing. [ Ch,9 fig. 1 tab. 11 ref.

  5. Dynamic characteristics of the CK5116 CNC lathe vibration system%CK5116数控立式车床振动系统动态特性的确定

    Institute of Scientific and Technical Information of China (English)

    殊海燕

    2012-01-01

    在简要介绍数控机床模态测试原理的基础上,对某机床厂生产的CK5116数控立式车床的模态及动态特性进行了测试,获得了机床整机的固有频率、模态振型、阻尼比、动刚度、动柔度等动态特性参数.通过测试发现,该机床的立柱在沿y方向的振动是该机床的薄弱环节,导致y方向的动刚度显著降低.在综合分析的基础上,提出在立柱内增设加强筋的方式来提高机床整机系统的动态特性,为同类型机床的结构性能优化提供有效的参考.%After brief introducing the principle of the modal testing of CNC machine tools, such as modal and dynamic characteristics were tested for a machine tool factory produced CK5116 lathe, and obtained a machine tool's natural frequency, mode shapes, damping ratio, dynamic stiffness, dynamic flexibility and other dynamic parameters. Test found that the machine column along the y direction of vibration of the machine's weak link, resulting in the y direction the dynamic stiffness was significantly reduced in the comprehensive analysis, based on the proposed column of additional ribs way improve the dynamic characteristics of machine tool systems, the structure of the same type of performance optimization tools to provide effective reference.

  6. Study on the algorithm of vibration source identification based on the optical fiber vibration pre-warning system

    Science.gov (United States)

    Qu, Hongquan; Ren, Xuecong; Li, Guoxiang; Li, Yonghong; Zhang, Changnian

    2015-06-01

    One of the key technologies for optical fiber vibration pre-warning system (OFVWS) refers to identifying the vibration source accurately from the detected vibration signals. Because of many kinds of vibration sources and complex geological structures, the implement of identifying vibration sources presents some interesting challenges which need to be overcome in order to achieve acceptable performance. This paper mainly conducts on the time domain and frequency domain analysis of the vibration signals detected by the OFVWS and establishes attribute feature models including an energy information entropy model to identify raindrop vibration source and a fundamental frequency model to distinguish the construction machine and train or car passing by. Test results show that the design and selection of the feature model are reasonable, and the rate of identification is good.

  7. 吸振器底座对减振效果的影响研究%Influence of the base of vibration absorber on vibration attenuation effect

    Institute of Scientific and Technical Information of China (English)

    徐振邦; 吴清文

    2014-01-01

    When the vibration absorber is applied to attenuate the vibration of flexible structures,the influence caused by the base of the vibration absorber cannot be ignored.In order to understand the characteristics of the influence, a mathematical model of the system composed of the vibration absorber with the base and a clamped-clamped beam was established.With the model,the vibration attenuation effects of the vibration absorbers were analysed by using the target criterion of power flow and vibration magnitude.The performances caused by the location,size,mass and the number of connection points were investigated emphatically.The results show that the vibration attenuation effect and the effective frequency range of the vibration absorber can be improved by optimizing the base.%吸振器用于柔性结构的振动控制时,其底座的影响将不可忽略。为进一步了解底座影响的程度和特点,开展了相关研究。通过子结构导纳综合法建立了柔性主系统和有底座吸振器耦合的动力学模型,以系统中的净功率流和振幅为考核指标,进行了仿真研究。重点考察了底座安装位置、尺寸、质量以及底座安装点个数对减振效果的影响。研究结果表明:通过合理优化底座参数,能够有效拓展吸振器的减振带宽,进一步改善吸振器减振效果。

  8. 五轴数控机床的空间误差建模与解耦补偿分析%Volumetric error modeling and decoupled error compensation analysis of five-axis CNC machine tools

    Institute of Scientific and Technical Information of China (English)

    要小鹏; 殷国富; 方辉; 程锦; 李光明

    2011-01-01

    针对五轴联动数控机床的位置与姿态误差补偿过程中各运动轴的误差补偿量与刀具和工件间的误差值耦合关系较为复杂的问题,在解析五轴机床运动学方程的基础上,利用多轴机床的误差运动学原理,建立了用各运动轴坐标系变换矩阵描述的机床误差模型.基于小误差补偿运动假设,分析了误差运动和补偿运动间的相互关系,对五轴机床各运动轴的位置与方向的误差补偿运动进行了解耦,建立了五轴数控机床的一种新的空间几何误差补偿模型和补偿算法.基于此算法开发了具有空间补偿功能的后处理模块,并通过实验验证了该模块在提高机床加工精度方面的有效性.%Aiming at the problem that the position and orientation error compensation of a five-axis machine tool is more complicated because of the complex coupled effects between the joint variables and the position/orientation of the tools and work-piece, the paper gives a volumetric error model by using the coordinate transformation method on the basis of analyzing the kinematics equations of five-axis machine tools and multi-axis machine tools' error kinematics principle. Based on the rigid body kinematics with small error assumption and the analysis of error motions and the compensation motions, a new volumetric error compensation model and a compensation algorithm are presented by decoupling the error compensation motions, thus the position and orientation compensation values of the joint variables can be obtained finally with the model. A new post-processing module was created by the compensation algorithm , and it was tested by experiment with the five-axis machine tools and the experimental results show that the machining accuracy can be improved effectively when using it.

  9. U-shape magnetostrictive vibration based power generator for universal use

    Science.gov (United States)

    Ueno, T.

    2016-04-01

    Vibrational power generator extracts electrical energy from ambient vibration. Author invented novel configuration using magnetostrictive material. The device is based on parallel beams of iron-gallium alloy and magnetic material, and features high efficiency, high robustness, and low electrical impedance. In this paper, author proposes U-shape generator for universal use. It consists of the parallel beams and fixed and free end beams forming U-shape frame flexibly modified for variety of mechanical input. Miniature U-shape prototype using Fe-Ga rod 6 by 0.5 by 13 mm3 exhibited average power of 3.7 mW under vibration of 166 Hz and 2.5 G. L-shape type was demonstrated to generate electromotive force by two directional vibrations. In switch type, maximum energy of 0.7 mJ was retrieved by one pushing force. The performances are sufficient to drive wireless module for heath monitoring and remote control.

  10. Vibration-displacement measurements based on the phase tracking of an optical fiber Michelson interferometer

    Science.gov (United States)

    Xie, Fang; Chen, Zhimin; Ren, Junyu; Feng, Qibo

    2009-04-01

    A vibration-displacement measurement system based on tracking the phase variation of an optical fiber Michelson interferometer with electronic feedback loops is presented. The measurement system includes two sets of electronic feedback loops. One electronic feedback loop is used to compensate for the low frequency drifts in the phase of the interferometric signal that results from environmental disturbances, while the other one is used to track the phase variation induced by the measured vibration displacement, and thus realize the measurement of the vibration displacement and provide a sense of direction of the displacement simultaneously. The measurement system is designed to be capable of measuring vibration displacement with frequencies ranging from 1.5 to 200 Hz, with measurement resolution reaching 13 nm.

  11. Vibration measurement based on the optical cross-correlation technique with femtosecond pulsed laser

    Science.gov (United States)

    Han, Jibo; Wu, Tengfei; Zhao, Chunbo; Li, Shuyi

    2016-10-01

    Two vibration measurement methods with femtosecond pulsed laser based on the optical cross-correlation technique are presented independently in this paper. The balanced optical cross-correlation technique can reflect the time jitter between the reference pluses and measurement pluses by detecting second harmonic signals using type II phase-matched nonlinear crystal and balanced amplified photo-detectors. In the first method, with the purpose of attaining the vibration displacement, the time difference of the reference pulses relative to the measurement pluses can be measured using single femtosecond pulsed laser. In the second method, there are a couple of femtosecond pulsed lasers with high pulse repetition frequency. Vibration displacement associated with cavity length can be calculated by means of precisely measuring the pulse repetition frequency. The results show that the range of measurement attains ±150μm for a 500fs pulse. These methods will be suited for vibration displacement measurement, including laboratory use, field testing and industrial application.

  12. Vibration signal analysis of main coolant pump flywheel based on Hilert-Huang transform

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Meiru; Xia, Hong; Sun, Lin; Li, Bin; Yang, Yang [Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, College of Nuclear Science and Technology, Harbin Engineering University, Harbin (China)

    2015-03-15

    In this paper, a three-dimensional model for the dynamic analysis of a flywheel based on the finite element method is presented. The static structure analysis for the model provides stress and strain distribution cloud charts. The modal analysis provides the basis of dynamic analysis due to its ability to obtain the natural frequencies and the vibration made vectors of the first 10 orders. The results show the main faults are attrition and cracks, while also indicating the locations and patterns of faults. The harmonic response simulation was performed to gain the vibration response of the flywheel under operation. In this paper, we present a Hilberte-Huang transform (HHT) algorithm for flywheel vibration analysis. The simulation indicated that the proposed flywheel vibration signal analysis method performs well, which means that the method can lay the foundation for the detection and diagnosis in a reactor main coolant pump.

  13. Eigenvalue and stability analysis for transverse vibrations of axially moving strings based on Hamiltonian dynamics

    Institute of Scientific and Technical Information of China (English)

    Yuefang Wang; Lihua Huang; Xuetao Liu; Keren Wang

    2005-01-01

    The Hamiltonian dynamics is adopted to solve the eigenvalue problem for transverse vibrations of axially moving strings. With the explicit Hamiltonian function the canonical equation of the free vibration is derived. Non-singular modal functions are obtained through a linear, symplectic eigenvalue analysis, and the symplectic-type orthogonality conditions of modes are derived. Stability of the transverse motion is examined by means of analyzing the eigenvalues and their bifurcation, especially for strings transporting with the critical speed. It is pointed out that the motion of the string does not possess divergence instability at the critical speed due to the weak interaction between eigenvalue pairs. The expansion theorem is applied with the non-singular modal functions to solve the displacement response to free and forced vibrations. It is demonstrated that the modal functions can be used as the base functions for solving linear and nonlinear vibration problems.

  14. Identification for Active Vibration Control of Flexible Structure Based on Prony Algorithm

    Directory of Open Access Journals (Sweden)

    Xianjun Sheng

    2016-01-01

    Full Text Available Flexible structures have been widely used in many fields due to the advantages of light quality, small damping, and strong flexibility. However, flexible structures exhibit the vibration in the process of manipulation, which reduces the pointing precision of the system and causes fatigue of the machine. So, this paper focuses on the identification method for active vibration control of flexible structure. The modal parameters and transfer function of the system are identified from the step response signal based on Prony algorithm, while the vibration is attenuated by using the input shaping technique designed according to the parameters identified from the Prony algorithm. Eventually, the proposed approach is applied to the most common flexible structure, a piezoelectric cantilever beam actuated by Macro Fiber Composite (MFC. The experimental results demonstrate that the Prony algorithm is very effective and accurate on the dynamic modeling of flexible structure and input shaper could significantly reduce the vibration and improve the response speed of system.

  15. Dynamic Interaction between Machine, Tool, and Substrate in Bobbin Friction Stir Welding

    Directory of Open Access Journals (Sweden)

    Mohammad K. Sued

    2016-01-01

    Full Text Available The bobbin friction stir welding (BFSW process has benefits for welding aluminium alloy 6082-T6 in the boat-building industry. However this alloy is difficult to weld in the thin state. There are a large number of process variables and covert situational factors that affect weld quality. This paper investigates how tool holder and machine-type affect BFSW weld quality of 4 mm Al6082-T6. The variables were tool features (three types, machine-controller type (two types, and tool holder (fixed versus floating. Fourier analysis was performed on motor spindle current to determine the frequency response of the machine. An interaction was found between the computer numerical control (CNC, the degrees of freedom of the tool holder, and the substrate (workpiece. The conventional idea that the welding tool has a semisteady interaction with the substrate is not supported. Instead the interaction is highly dynamic, and this materially affects the weld quality. Specific vibrational interactions are associated with poor welding. The CNC machine-type also emerges as a neglected variable that needs to be given attention in the selection of process parameters. Although compliance in the tool holder might seem useful, it is shown to have negative consequences as it introduces tool positioning problems.

  16. Vibration Response and Power Flow Characteristics of a Flexible Manipulator with a Moving Base

    Directory of Open Access Journals (Sweden)

    Yufei Liu

    2015-01-01

    Full Text Available Flexible manipulator generally can be modeled as a coupling system with a flexible beam and a rigid moving base. This paper investigates the vibration responses and power flow of a flexible manipulator with a moving base (FMMB. Considering the motion characteristics of the rigid base, the moving base is modeled to have a motion with disturbances, and the dynamic model of the FMMB is established. With the dynamic model, vibration responses of the FMMB for the rigid base having disturbance velocities and accelerations are specifically presented. Subsequently, to investigate the effect of the disturbances on the vibration energy distributions of the FMMB, power flow of the FMMB is exhibited. To verify the dynamic model, an ADAMS physical model of the FMMB is constructed. It reveals that the motion characteristics of the rigid base have a noticeable effect on the vibration responses and power flow of the FMMB and should be considered. The results are significant and contribute to the vibration control of flexible manipulators.

  17. 浅谈数控机床的爬行现象%Crawling Phenomenon of CNC Machine Tools

    Institute of Scientific and Technical Information of China (English)

    甘佳良

    2011-01-01

    CNC machine tool feed at low speed occurs when the non-uniform crawling on the machining accuracy and surface quality is very negative.This paper studies the phenomenon of a mathematical model of crawl established,an analysis of the phenomenon of the critical speed crawling,derived the various factors affecting the critical speed.%数控机床在低速进给时,会发生非匀速爬行,对加工精度和工件表面质量非常不利。本文主要研究爬行现象的一种数学模型建立,分析发生爬行现象的临界速度,推导出影响临界速度的各个因素。

  18. A nonlinear multi-mode wideband piezoelectric vibration-based energy harvester using compliant orthoplanar spring

    Energy Technology Data Exchange (ETDEWEB)

    Dhote, Sharvari, E-mail: sharvari.dhote@mail.utoronto.ca; Zu, Jean; Zhu, Yang [Department of Mechanical and Industrial Engineering, University of Toronto, 5 King' s College Road, Toronto, Ontario M5S-3G8 (Canada)

    2015-04-20

    In this paper, a nonlinear wideband multi-mode piezoelectric vibration-based energy harvester (PVEH) is proposed based on a compliant orthoplanar spring (COPS), which has an advantage of providing multiple vibration modes at relatively low frequencies. The PVEH is made of a tri-leg COPS flexible structure, where three fixed-guided beams are capable of generating strong nonlinear oscillations under certain base excitation. A prototype harvester was fabricated and investigated through both finite-element analysis and experiments. The frequency response shows multiple resonance which corresponds to a hardening type of nonlinear resonance. By adding masses at different locations on the COPS structure, the first three vibration modes are brought close to each other, where the three hardening nonlinear resonances provide a wide bandwidth for the PVEH. The proposed PVEH has enhanced performance of the energy harvester in terms of a wide frequency bandwidth and a high-voltage output under base excitations.

  19. Research on Sensor-less Performance Evaluation Technology for Number Control Machine Tool Servo Driving System%数控机床伺服进给系统无传感器性能评估技术的研究

    Institute of Scientific and Technical Information of China (English)

    韩军; 周慧君; 常瑞丽

    2014-01-01

    Based on the research platform of position-closed-loop servo control system of servo driving system of numerical control (NC)machine tool,the testing principles of sensor-less of Hall current sensor in servo amplifier,encoder and grating scale were re-searched,and the feasibility of information of sensor-less used in faults evaluation and relationship between faults and information of sensor-less were explored. Besides,different data sampling methods were presented by aiming at different NC systems. It is the base of performance evaluation of servo driving system of NC machine tool on-line.%以位置全闭环控制策略的数控机床伺服进给系统为研究平台,研究伺服放大器中霍尔电流传感器、编码器与光栅尺等无传感器测试原理,探索无传感器信息与故障的关联性以及无传感器信息用于故障评估的可行性;并且针对不同类型的数控系统,提出不同的数据采集方法。为数控机床伺服进给系统在线性能评估奠定了基础。

  20. 浅谈PLC机械加工数控机床改造技术%On the transformation technology of PLC machine tool

    Institute of Scientific and Technical Information of China (English)

    刘洋

    2015-01-01

    The powerful function of numerical control machine tool can not be separated from the use of PLC technology,text through the PLC technology to explain the simple introduction of the PLC machine tool transformation technology, to achieve the maximization of corporate profits.%数控机床的强大功能离不开PLC技术的采用,文本通过对PLC技术的简单介绍来阐述PLC机械加工数控机床改造技术,实现企业利润的最大化.

  1. Development of microcontroller-based acquisition and processing unit for fiber optic vibration sensor

    Science.gov (United States)

    Suryadi; Puranto, P.; Adinanta, H.; Waluyo, T. B.; Priambodo, P. S.

    2017-04-01

    Microcontroller based acquisition and processing unit (MAPU) has been developed to measure vibration signal from fiber optic vibration sensor. The MAPU utilizes a 32-bit ARM microcontroller to perform acquisition and processing of the input signal. The input signal is acquired with 12 bit ADC and processed using FFT method to extract frequency information. Stability of MAPU is characterized by supplying a constant input signal at 500 Hz for 29 hours and shows a stable operation. To characterize the frequency response, input signal is swapped from 20 to 1000 Hz with 20 Hz interval. The characterization result shows that MAPU can detect input signal from 20 to 1000 Hz with minimum signal of 4 mV RMS. The experiment has been set that utilizes the MAPU with singlemode-multimode-singlemode (SMS) fiber optic sensor to detect vibration which is induced by a transducer in a wooden platform. The experimental result indicates that vibration signal from 20 to 600 Hz has been successfully detected. Due to the limitation of the vibration source used in the experiment, vibration signal above 600 Hz is undetected.

  2. A Fiber Bragg Grating Sensing-Based Micro-Vibration Sensor and Its Application.

    Science.gov (United States)

    Li, Tianliang; Tan, Yuegang; Zhou, Zude

    2016-04-15

    This paper proposes a fiber Bragg grating sensing-based micro-vibration sensor. The optical fiber has been directly treated as an elastomer to design the micro-vibration sensor, which possesses two FBGs. The mass is fixed on the middle of the fiber, and the vertical vibration of the mass has been converted into the axial tension/compression of the fiber. The principle of the sensor has been introduced, and the experiment conclusions show that the sensor sensitivity is 2362 pm/g within the range of 200-1200 mm/s², which is consistent with theoretical analysis sensitivity of 2532.6 pm/g, and it shows an excellent linearity of 1.376%, while the resonant frequency of the sensor is 34 Hz, and the flat frequency range resides in the 0-22 Hz range. When used to measure micro-vibrations, its measured frequency relative error is less than 1.69% compared with the values acquired with a MEMS accelerometer, and the amplitude values of its measured vibration signal are consistent with the MEMS accelerometer under different excitation conditions too, so it can effectively realize the micro-vibration measurements.

  3. FPGA-Based Fused Smart Sensor for Dynamic and Vibration Parameter Extraction in Industrial Robot Links

    Directory of Open Access Journals (Sweden)

    Rene de Jesus Romero-Troncoso

    2010-04-01

    Full Text Available Intelligent robotics demands the integration of smart sensors that allow the controller to efficiently measure physical quantities. Industrial manipulator robots require a constant monitoring of several parameters such as motion dynamics, inclination, and vibration. This work presents a novel smart sensor to estimate motion dynamics, inclination, and vibration parameters on industrial manipulator robot links based on two primary sensors: an encoder and a triaxial accelerometer. The proposed smart sensor implements a new methodology based on an oversampling technique, averaging decimation filters, FIR filters, finite differences and linear interpolation to estimate the interest parameters, which are computed online utilizing digital hardware signal processing based on field programmable gate arrays (FPGA.

  4. FPGA-based fused smart sensor for dynamic and vibration parameter extraction in industrial robot links.

    Science.gov (United States)

    Rodriguez-Donate, Carlos; Morales-Velazquez, Luis; Osornio-Rios, Roque Alfredo; Herrera-Ruiz, Gilberto; de Jesus Romero-Troncoso, Rene

    2010-01-01

    Intelligent robotics demands the integration of smart sensors that allow the controller to efficiently measure physical quantities. Industrial manipulator robots require a constant monitoring of several parameters such as motion dynamics, inclination, and vibration. This work presents a novel smart sensor to estimate motion dynamics, inclination, and vibration parameters on industrial manipulator robot links based on two primary sensors: an encoder and a triaxial accelerometer. The proposed smart sensor implements a new methodology based on an oversampling technique, averaging decimation filters, FIR filters, finite differences and linear interpolation to estimate the interest parameters, which are computed online utilizing digital hardware signal processing based on field programmable gate arrays (FPGA).

  5. Vibrational spectra and DFT calculations of the vibrational modes of Schiff base C18H17N3O2

    Science.gov (United States)

    Antunes, J. A.; Silva, L. E.; Bento, R. R. F.; Teixeira, A. M. R.; Freire, P. T. C.; Faria, J. L. B.; Ramos, R. J.; Silva, C. B.; Lima, J. A.

    2012-04-01

    The Schiff base 4-{[(1E)-(2-Hydroxyphenyl)methylidene]amino}-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one (C18H17N3O2) is a synthetic compound with a variety of scientific and technological applications, such as clinic, analytic and pharmacologic. In this work FT-Raman spectrum and FT-infrared spectrum of C18H17N3O2 were investigated at 300 K. Vibrational wavenumber and wave vector have been predicted using Density Functional Theory (B3LYP) calculations with the 6-31 G(d,p) basis set. The description of the normal modes was performed by means of the potential energy distribution. A comparison with experiment allowed us to assign most of the normal modes of the crystal.

  6. Vision-based online vibration estimation of the in-vessel inspection flexible robot with short-time Fourier transformation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hesheng [Key Laboratory of System Control and Information Processing, Ministry of Education of China (China); Department of Automation, Shanghai Jiao Tong University, Shanghai 200240 (China); Chen, Weidong, E-mail: wdchen@sjtu.edu.cn [Key Laboratory of System Control and Information Processing, Ministry of Education of China (China); Department of Automation, Shanghai Jiao Tong University, Shanghai 200240 (China); Xu, Lifei; He, Tao [Key Laboratory of System Control and Information Processing, Ministry of Education of China (China); Department of Automation, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2015-10-15

    Highlights: • Vision-based online vibration estimation method for a flexible arm is proposed. • The vibration signal is obtained by image processing in unknown environments. • Vibration parameters are estimated by short-time Fourier transformation. - Abstract: The vibration should be suppressed if it happens during the motion of a flexible robot or under the influence of external disturbance caused by its structural features and material properties, because the vibration may affect the positioning accuracy and image quality. In Tokamak environment, we need to get the real-time vibration information on vibration suppression of robotic arm, however, some sensors are not allowed in the extreme Tokamak environment. This paper proposed a vision-based method for online vibration estimation of a flexible manipulator, which is achieved by utilizing the environment image information from the end-effector camera to estimate its vibration. Short-time Fourier Transformation with adaptive window length method is used to estimate vibration parameters of non-stationary vibration signals. Experiments with one-link flexible manipulator equipped with camera are carried out to validate the feasibility of this method in this paper.

  7. Numerical and Experimental Studies of a Light-Weight Auxetic Cellular Vibration Isolation Base

    Directory of Open Access Journals (Sweden)

    Xiang-Wen Zhang

    2016-01-01

    Full Text Available This paper presents a preliminary study of the dynamic performance of a novel light-weight auxetic (negative Poisson’s ratio cellular vibration isolation base constituted by reentrant hexagonal honeycombs. Numerical and experimental analyses were conducted to reveal the effects of Poisson’s ratio (cell angle and relative density (cell thickness of these reentrant honeycombs on the dynamic performance of this novel base and to propose design guidelines for the best use of the auxetic cellular vibration isolation system. By doing numerical analysis, we found that, by decreasing the relative density of reentrant honeycombs and increasing Poisson’s ratio of them, excellent vibration isolation performance of the auxetic cellular base will be achieved. This analysis was followed by static, modal, and frequency response tests, which verified the results of the numerical analysis.

  8. GA-Based Autonomous Design of Robust Fast and Precise Positioning Considering Machine Stand Vibration Suppression

    Science.gov (United States)

    Ito, Kazuaki; Nagata, Ryo; Iwasaki, Makoto; Matsui, Nobuyuki

    This paper presents a novel Genetic Algorithm (GA)-based autonomous compensator design and position command shaping considering the stand vibration suppression for the fast-response and high-precision positioning of mechatronic systems. The positioning system is mainly composed of a robust 2-degrees-of-freedom (2DOF) controller based on the coprime factorization description. The feedback compensator based on H∞ design framework in the 2DOF controller ensures the robustness against the variations of resonant vibration mode. The feedforward compensator and position command, on the other hand, can be autonomously designed by the optimization capability of GA, in order to achieve the desired positioning performance and to suppress the machine stand vibration. The effectiveness of the proposed optimal design has been verified by experiments using a table drive system with ball screw.

  9. Vibration-Based Damage Detection in Beams by Cooperative Coevolutionary Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Kittipong Boonlong

    2014-03-01

    Full Text Available Vibration-based damage detection, a nondestructive method, is based on the fact that vibration characteristics such as natural frequencies and mode shapes of structures are changed when the damage happens. This paper presents cooperative coevolutionary genetic algorithm (CCGA, which is capable for an optimization problem with a large number of decision variables, as the optimizer for the vibration-based damage detection in beams. In the CCGA, a minimized objective function is a numerical indicator of differences between vibration characteristics of the actual damage and those of the anticipated damage. The damage detection in a uniform cross-section cantilever beam, a uniform strength cantilever beam, and a uniform cross-section simply supported beam is used as the test problems. Random noise in the vibration characteristics is also considered in the damage detection. In the simulation analysis, the CCGA provides the superior solutions to those that use standard genetic algorithms presented in previous works, although it uses less numbers of the generated solutions in solution search. The simulation results reveal that the CCGA can efficiently identify the occurred damage in beams for all test problems including the damage detection in a beam with a large number of divided elements such as 300 elements.

  10. Piezoelectric rotational mixer based on a first bending vibration mode.

    Science.gov (United States)

    Mashimo, Tomoaki

    2013-10-01

    We propose a miniature piezoelectric mixer that can rotate a liquid inside a hole of several millimeters diameter. The mixer has dimensions 14 × 14 × 10 mm with a through-hole (7 mm), and piezoelectric elements bonded to its four identical sides. When the first bending vibration mode of the mixer is excited by ac voltages, rotational flow of liquid is generated by the rotation of an acoustic field (acoustic streaming) in the through-hole. This technology is useful in automating mixing processes such as the mixing by hand of a few drops of blood in medical testing. In this paper, we verify the driving principle experimentally and examine the characteristics of a prototype mixer, including the induced flow velocity, under changes of the amplitude and frequency of the applied voltages. A plastic test tube, used to prevent contamination, is inserted to the through-hole, and the liquid inside the tube is mixed by rotation of the acoustic field.

  11. Theory of vibration protection

    CERN Document Server

    Karnovsky, Igor A

    2016-01-01

    This text is an advancement of the theory of vibration protection of mechanical systems with lumped and distributed parameters. The book offers various concepts and methods of solving vibration protection problems, discusses the advantages and disadvantages of different methods, and the fields of their effective applications. Fundamental approaches of vibration protection, which are considered in this book, are the passive, parametric and optimal active vibration protection. The passive vibration protection is based on vibration isolation, vibration damping and dynamic absorbers. Parametric vibration protection theory is based on the Shchipanov-Luzin invariance principle. Optimal active vibration protection theory is based on the Pontryagin principle and the Krein moment method. The book also contains special topics such as suppression of vibrations at the source of their occurrence and the harmful influence of vibrations on humans. Numerous examples, which illustrate the theoretical ideas of each chapter, ar...

  12. CCD在数控机床闭环控制系统中的应用%Application of CCD in Close-loop Control System of NC Machine Tools

    Institute of Scientific and Technical Information of China (English)

    魏宏波; 王玮

    2016-01-01

    High precision measurement is the prerequisite for the realization of high precision control.Based on the analysis of ex-isting control system of NC machine tools, in order to improve the measurement precision and reduce the system cost, the traditional grating was combined with CCD to accomplish the closed-loop control of CNC.The principle and method of displacement measurement system were introduced.It provides a new idea for the closed-loop control of CNC machine tools.%高精度测量是实现高精度控制的前提。通过对现有数控机床控制系统的分析,为了提高测量精度、降低系统成本,将传统光栅与CCD结合起来完成数控机床闭环系统的控制,介绍了系统位移测量原理及方法,为数控机床闭环控制提供新思路。

  13. 一种新型五自由度并联机床的概念设计与运动分析%Configuration Design and Kinematics Aanalysis of a New 5- DOF Parallel Machine Tool

    Institute of Scientific and Technical Information of China (English)

    王海东; 韩玉; 杨炳恒

    2011-01-01

    According to the screw theory, the moving characteristic of the PKPaU machine is analyzed. One type of spatial new 4 - PSS/PRPaU parallel machine tool is proposed, its platform has three translations and two relations. The position and velocity analytic equation are constructed based on the coordinate transformation, it has eight positive and reverse positional solution, the forward and the inverse Jacobian matrix of the parallel machine tool is deduced.%根据螺旋理论系统分析了恰约束主动支链PRPaU的运动特点,在此基础上提出了一种能实现三维移动和二维转动的4- PSS/PRPaU并联机床.利用坐标变换法建立了该并联机床的位置和速度解析方程,并推导出了机床的正、逆雅克比矩阵.

  14. Volumetric error modeling and sensitivity analysis for a five-axis ultra-precision machine tool%超精密五轴机床的几何误差建模和灵敏度分析

    Institute of Scientific and Technical Information of China (English)

    余文利; 姚鑫骅

    2015-01-01

    Studies the volumetric error modeling and its sensitivity analysis for the purpose of machine design .The volumetric er-ror model of a five-axis machine tool with the configuration of RTTTR is established based on rigid body kinematics and homoge -neous transformation matrix ,in which 37 error components are involved .The sensitivity analysis of volumetric error regarding 37 error components is carried out respectively .The analysis results will be used for the accuracy design and manufacture of a five -axis ultra-precision machine tool .%基于设计出超精密机床的目的,研究了机床的几何误差建模和误差的灵敏度分析。基于刚体运动学和齐次变换矩阵( Homogeneous Transformation Matrix ,HTM)建立了RTTTR配置的超精密五轴机床的几何误差模型,模型涉及37个误差分量。分别对37个误差分量进行了几何误差的灵敏度分析,分析结果将应用于超精密五轴机床的设计与制造上。

  15. The multilayer and wide-deck vibrating screen based on the innovative long-span vibration exciter

    Science.gov (United States)

    Zeng, Ming; Xu, Zonglin; Zhang, Jinnan; Zhang, Minghong

    2017-09-01

    The multilayer and wide-deck innovative single plasmid vibration screen is applicable to the petroleum drilling and the other relevant industries. The structural features and advantages of the components are illustrated, and the innovative long-span vibration exciter together with the steel rope saddle block flexible coupling is emphatically analyzed. Two engineering examples are provided to make the explanation.

  16. Vibration control for precision manufacturing at Sandia National Laboratories

    Science.gov (United States)

    Hinnerichs, Terry D.; Martinez, David R.

    1995-05-01

    Sandia National Laboratories performs R&D in structural dynamics and vibration suppression of precision applications in weapon systems, space, underwater, transportation and civil structures. Over the last decade these efforts have expanded into the areas of active vibration control and 'smart' structures and material systems, In addition, major resources have been focused towards technology to support weapon product development and agile manufacturing capability for defense and industrial applications. This paper will briefly describe the structural dynamics modeling and verification process that supports vibration control and some specific applications of these techniques to manufacturing in the areas of lithography, machine tools and flexible robotics.

  17. Vibration control for precision manufacturing at Sandia National Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Hinnerichs, T.; Martinez, D. [Sandia National Labs., Albuquerque, NM (United States). Structural Dynamics and Vibration Control Dept.

    1995-04-01

    Sandia National Laboratories performs R and D in structural dynamics and vibration suppression for precision applications in weapon systems, space, underwater, transportation and civil structures. Over the last decade these efforts have expanded into the areas of active vibration control and ``smart`` structures and material systems. In addition, Sandia has focused major resources towards technology to support weapon product development and agile manufacturing capability for defense and industrial applications. This paper will briefly describe the structural dynamics modeling and verification process currently in place at Sandia that supports vibration control and some specific applications of these techniques to manufacturing in the areas of lithography, machine tools and flexible robotics.

  18. Control of Rotor-Blade Coupled Vibrations Using Shaft-Based Actuation

    DEFF Research Database (Denmark)

    Christensen, Rene H.; Santos, Ilmar

    2006-01-01

    When implementing active control into bladed rotating machines aiming at reducing blade vibrations, it can be shown that blade as well as rotor vibrations can in fact be controlled by the use of only shaft-based actuation. Thus the blades have to be deliberately mistuned. This paper investigates...... of modal controllability and observability converge toward steady levels as the degree of mistuning is increased. Finally, experimental control results are presented to prove the theoretical conclusions and to show the feasibility of controlling rotor and blade vibrations by means of shaft-based actuation...... the dynamical characteristics of a mistuned bladed rotor and shows how, why and when a bladed rotor becomes controllable and observable if properly mistuned. As part of such investigation modal controllability and observability of a tuned as well as a mistuned coupled rotor-blade system are analysed...

  19. Motion Planning for Vibration Reducing of Free-floating Redundant Manipulators Based on Hybrid Optimization Approach

    Institute of Scientific and Technical Information of China (English)

    LIAO Yihuan; LI Daokui; TANG Guojin

    2011-01-01

    This paper is concerned with optimal motion planning for vibration reducing of flee-floating flexible redundant manipulators.Firstly,dynamic model of the system is established based on Lagrange method,and the motion planning model for vibration reducing is proposed.Secondly,a hybrid optimization approach employing Gauss pseudospectral method(GPM) and direct shooting method(DSM),is proposed to solve the motion planning problem.In this approach,the motion planning problem is transformed into a non-linear parameter optimization problem using GPM,and genetic algorithm(GA) is employed to locate the approximate solution.Subsequently,an optimization model is formulated based on DSM,and sequential quadratic programming (SQP) algorithm is used to obtain the accurate solution,with the approximate solution as an initial reference solution.Finally,several numerical simulations are investigated,and the global vibration or residual vibration of flexible link is obviously reduced by the joint trajectory which is obtained by the hybrid optimization approach.The numerical simulation results indicate that the approach is effective and stable to the motion planning problem of vibration reducing.

  20. Active vibration control of multibody system with quick startup and brake based on active damping

    Institute of Scientific and Technical Information of China (English)

    TANG Hua-ping; TANG Yun-jun; TAO Gong-an

    2006-01-01

    A kind of active vibration control method was presented based on active damping and optimization design for driving load of multibody system with quick startup and brake. Dynamical equation of multibody system with quick startup and brake and piezoelectric actuators intelligent structure was built. The optimum driving load was calculated by applying the presented method. The self-sensing and self-tuning closed-loop active vibration control in quick startup and brake process was realized. The control algorithm, using local velocity negative feedback, i.e. the output of a sensor only affects the output of the actuator collocated, can induce damping effectively to actively suppress the system vibration. Based on the optimization design for driving load of multibody system with quick startup and bake, the active damping of piezoelectric actuators intelligent structure was used to farther suppress the vibration of system. Theoretical analysis and calculation of numerical show that the proposed method makes the vibration of system decrease more than the optimal design method for driving load of multibody system.

  1. Performance of tensor decomposition-based modal identification under nonstationary vibration

    Science.gov (United States)

    Friesen, P.; Sadhu, A.

    2017-03-01

    Health monitoring of civil engineering structures is of paramount importance when they are subjected to natural hazards or extreme climatic events like earthquake, strong wind gusts or man-made excitations. Most of the traditional modal identification methods are reliant on stationarity assumption of the vibration response and posed difficulty while analyzing nonstationary vibration (e.g. earthquake or human-induced vibration). Recently tensor decomposition based methods are emerged as powerful and yet generic blind (i.e. without requiring a knowledge of input characteristics) signal decomposition tool for structural modal identification. In this paper, a tensor decomposition based system identification method is further explored to estimate modal parameters using nonstationary vibration generated due to either earthquake or pedestrian induced excitation in a structure. The effects of lag parameters and sensor densities on tensor decomposition are studied with respect to the extent of nonstationarity of the responses characterized by the stationary duration and peak ground acceleration of the earthquake. A suite of more than 1400 earthquakes is used to investigate the performance of the proposed method under a wide variety of ground motions utilizing both complete and partial measurements of a high-rise building model. Apart from the earthquake, human-induced nonstationary vibration of a real-life pedestrian bridge is also used to verify the accuracy of the proposed method.

  2. 故障强度为边界浴盆形状的数控机床可靠性分析%Reliability Analysis of Numerical Control Machine Tools with Bounded and Bathtub Shaped Failure Intensity

    Institute of Scientific and Technical Information of China (English)

    任丽娜; 芮执元; 李建华

    2014-01-01

    In minimal repair, in order to describe the failure process of numerical control(NC) machine tools experiencing both early failures and deterioration phenomena, and operating so long that the intensity function approaches a finite asymptote as the system operating time grows, a new four-parameter non-homogeneous Poisson process model is proposed. The characteristics of the model are discussed, and the physical meaning of its parameters is given, calculating formula of point estimation for model parameters and reliability indices such as the minimum intensity value and the time of minimum intensity are all derived, then a method of model selection for reliability assessment of two NC machine tools is provided based on the likelihood ratio statistic, and the model evaluation criterion is given based on the index of goodness-of-fit test. The real failure data of two NC machine tools are analyzed by using the proposed method, the results show that this method can quantitatively evaluate the machine tools’ lasting time of early failure period, it is suitable for describing the failure process of NC machine tools with bounded and bathtub shaped failure trend, and can provide a theoretical basis for eliminating as much early failures as possible before the NC machine tools leave the factory.%最小维修情况下,为描述经历早期故障和耗损故障且故障强度随工作时间增加而趋近于某一常数的数控机床故障过程,提出一种新的4参数非齐次泊松过程模型。讨论模型的特性,给出模型中各参数的物理意义,推导计算模型参数及诸如最小故障强度、最小故障强度对应的故障时刻等重要可靠性指标点估计的计算公式,基于似然比检验理论,给出两台数控机床可靠性评估的模型选择方法,并基于拟合优度检验指标R,给出模型评价准则。对两台数控机床故障数据进行分析,结果表明,该模型可定量评估机床的早期故障期

  3. An open CAM system for dentistry on the basis of China-made 5-axis simultaneous contouring CNC machine tool and industrial CAM software.

    Science.gov (United States)

    Lu, Li; Liu, Shusheng; Shi, Shenggen; Yang, Jianzhong

    2011-10-01

    China-made 5-axis simultaneous contouring CNC machine tool and domestically developed industrial computer-aided manufacture (CAM) technology were used for full crown fabrication and measurement of crown accuracy, with an attempt to establish an open CAM system for dental processing and to promote the introduction of domestic dental computer-aided design (CAD)/CAM system. Commercially available scanning equipment was used to make a basic digital tooth model after preparation of crown, and CAD software that comes with the scanning device was employed to design the crown by using domestic industrial CAM software to process the crown data in order to generate a solid model for machining purpose, and then China-made 5-axis simultaneous contouring CNC machine tool was used to complete machining of the whole crown and the internal accuracy of the crown internal was measured by using 3D-MicroCT. The results showed that China-made 5-axis simultaneous contouring CNC machine tool in combination with domestic industrial CAM technology can be used for crown making and the crown was well positioned in die. The internal accuracy was successfully measured by using 3D-MicroCT. It is concluded that an open CAM system for dentistry on the basis of China-made 5-axis simultaneous contouring CNC machine tool and domestic industrial CAM software has been established, and development of the system will promote the introduction of domestically-produced dental CAD/CAM system.

  4. The basic idea of fault diagnosis for CNC machine tools%关于数控机床故障诊断的基本思路

    Institute of Scientific and Technical Information of China (English)

    卫方

    2013-01-01

    With the wide application of CNC machine tools , CNC machine tool maintenance repair become more complex .Fault diagnosis and maintenance methods to understand and master the NC ma-chine tool is helpful to prolong the service life of equipment , reduce repair cost , avoid the occurrence of mechanical accident .Therefore, this paper propose the basic idea of fault diagnosis of CNC machine tools, thus simplifying the process of fault diagnosis , to improve the accuracy and rapidity of fault diagno-sis .%随着数控机床的广泛应用,数控机床的维护维修变得更为复杂。了解和掌握数控机床的故障诊断和养护方法有助于延长设备的使用寿命,减低维修的成本,避免机械事故的发生。因此,该文提出对数控机床故障诊断的基本思路,从而简化故障诊断过程,提高故障诊断的准确性和快速性。

  5. Design method of automotive powertrain mounting system based on vibration and noise limitations of vehicle level

    Science.gov (United States)

    Shangguan, Wen-Bin; Liu, Xiao-Ang; Lv, Zhao-Ping; Rakheja, Subhash

    2016-08-01

    The design logic and calculation method for determining mount stiffness and damping for a Powertrain Mounting System (PMS) based on reductions of vehicle vibration and noise contributed by mounts is proposed in this paper. Firstly, the design target for a PMS with regard to vibration and noise limitations of vehicle level contributed form mounts is described. Then a vehicle model with 13 Degree of Freedoms (DOFs) is proposed, which includes 6DOFs for the powertrain, 3 DOFs for the car body and 4DOFs for the four unsprung mass, and the dynamic equation for the model is derived. Some widely used models, such as the 6 DOFs model of the powertrain for the design calculation of a PMS, the 7 DOFs model (Body's 3 DOFs; unsprung mass's 4 DOFs) and the 9 DOFs model (powertrain's 6 DOFs; Body's 3 DOFs) for ride analysis of a vehicle, are the specific cases of the presented model of 13 DOF. Thirdly, the calculation method for obtaining the vibration of seat track and evaluation point and the noise at driver right ear is presented based on the mount forces and the vibration and noise transfer functions. An optimization process is proposed to get the mount stiffness and damping based on minimization of vehicle vibration and noise, and the optimized stiffness is validated by comparing the calculated vibration and noise and limitations. In the end of this paper, the natural frequencies and mode energies for the powertrain, the body and the unsprung mass are calculated using different models and the results are compared and analyzed.

  6. Study of the vibration of bulkhead-stiffened cylindrical shells by laser-based methods

    Science.gov (United States)

    Zhu, Ninghui

    The first part of this dissertation work deals with an experimental study of the vibration behavior of bulkhead stiffened cylindrical shells by using laser-based vibration measurement methods. Holographic interferometry and laser speckle photography are first demonstrated on revealing the dynamic behavior of a 22 ft long cylindrical shell. These methods are thereafter further explored to study the vibration characteristic of cylindrical shells with different stiffeners such as a full bulkhead or a partial bulkhead. Many experimentally obtained holograms and specklegrams reveal interesting features of the vibration of bulkhead stiffened cylindrical shells. The experimentally obtained results are compared with those obtained from a finite element model developed by General Dynamic Electric Boat Division, and the finite element model is generally validated. Mode localization theory is used to explain some interesting findings in experiments and the reason of some discrepancies between the finite element analysis and experiment results. The presence of irregularities in a weakly coupled structure such as a bulkhead-stiffened cylindrical shell is shown to be able to localize the modes of vibration and inhibit the propagation of vibration within the shell. A numerical simulation based on the finite element modal analysis indicates the validation of this explanation of the experimental findings. Thereafter, the eigensolutions of disordered, plate-stiffened cylindrical shell stiffened are derived by the use of receptance method. Numerical calculations are thereafter performed based upon this model and indeed reveal the exist of localized vibration in this kind of structure. This analytical study provides physical insights into the mode localization phenomenon in stiffened cylindrical shell type of structures from a more systematic manner. The conditions and the effect of mode localization on natural frequencies and mode shapes of cylindrical shell structure are also

  7. IIR filtering based adaptive active vibration control methodology with online secondary path modeling using PZT actuators

    Science.gov (United States)

    Boz, Utku; Basdogan, Ipek

    2015-12-01

    Structural vibrations is a major cause for noise problems, discomfort and mechanical failures in aerospace, automotive and marine systems, which are mainly composed of plate-like structures. In order to reduce structural vibrations on these structures, active vibration control (AVC) is an effective approach. Adaptive filtering methodologies are preferred in AVC due to their ability to adjust themselves for varying dynamics of the structure during the operation. The filtered-X LMS (FXLMS) algorithm is a simple adaptive filtering algorithm widely implemented in active control applications. Proper implementation of FXLMS requires availability of a reference signal to mimic the disturbance and model of the dynamics between the control actuator and the error sensor, namely the secondary path. However, the controller output could interfere with the reference signal and the secondary path dynamics may change during the operation. This interference problem can be resolved by using an infinite impulse response (IIR) filter which considers feedback of the one or more previous control signals to the controller output and the changing secondary path dynamics can be updated using an online modeling technique. In this paper, IIR filtering based filtered-U LMS (FULMS) controller is combined with online secondary path modeling algorithm to suppress the vibrations of a plate-like structure. The results are validated through numerical and experimental studies. The results show that the FULMS with online secondary path modeling approach has more vibration rejection capabilities with higher convergence rate than the FXLMS counterpart.

  8. A novel ring vibrating gyroscope based on side piezo-electrodes

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xin; WU Yu-lie; WU Xue-zhong; ZHANG Yong-meng; ZHENG Yu

    2016-01-01

    Solid-state wave gyroscope is one kind of high-performance vibrating gyroscopes. The present work develops a new type of solid-state wave gyroscope—a ring vibrating gyroscope driven by piezo-electrodes located on the sidewall of the structure. It has advantages of large vibrating amplitude, high energy conversion efficiency and compact structure. The working principle of the piezoelectric ring vibrating gyroscope is based on the inertia effect of the standing wave in the axisymmetric resonator caused by Coriolis force. The finite element method (FEM) analysis has been implemented to characterize the ring type resonator. The prototypal gyroscope was manufactured and has been trimmed by mechanical way. The harmonic response of the ring vibrating gyroscope has been tested. The resonating frequency of the ring type resonator is 3715.6 Hz and the frequency split of the two working modes before trimming was about 5 Hz and was reduced to sub-0.01 Hz after trimming procedure. The Q-factor of the ring type resonator was 2504. Then, the turntable experiment was implemented. The measured scale factor k is 9.24 mV/[(°)·s] and the full scale range of the gyroscope is larger than ±300 (°)/s.

  9. Two methods for damping torsional vibrations in DFIG-based wind generators using power converters

    Science.gov (United States)

    Zhao, Zuyi; Lu, Yupu; Xie, Da; Yu, Songtao; Wu, Wangping

    2017-01-01

    This paper proposes novel damping control algorithms by using static synchronous compensator (STATCOM) and energy storage system (ESS) to damp torsional vibrations in doubly fed induction generator (DFIG) based wind turbine systems. It first analyses the operating characteristics of STATCOM and ESS for regulating power variations to increase grid voltage stability. Then, new control strategies for STATCOM and ESS are introduced to damp the vibrations. It is followed by illustration of their effectiveness to damp the drive train torsional vibrations of wind turbines, which can be caused by grid disturbances, such as voltage sags and frequency fluctuations. Results suggest that STATCOM is a promising technology to mitigate the torsional vibrations caused by grid voltage sags. By contrast, the ESS connected to the point of common coupling (PCC) of wind turbine systems shows even obvious advantages because of its capability of absorbing/releasing both active and reactive power. It can thus be concluded that STATCOM is useful for stabilizing power system voltage fluctuations, and ESS is more effective both in regulating PCC voltage fluctuations and damping torsional vibrations caused by grid voltage frequency fluctuations.

  10. Vibrationally resolved UV/Vis spectroscopy with time-dependent density functional based tight binding

    CERN Document Server

    Rüger, Robert; van Lenthe, Erik; Heine, Thomas; Visscher, Lucas

    2016-01-01

    We report a time-dependent density functional based tight-binding (TD-DFTB) scheme for the calculation of UV/Vis spectra, explicitly taking into account the excitation of nuclear vibrations via the harmonic approximation. The theory of vibrationally resolved UV/Vis spectroscopy is first summarized from the viewpoint of TD-DFTB. The method is benchmarked against time-dependent density functional theory (TD-DFT) calculations for strongly dipole allowed excitations in various aromatic and polar molecules. Using the recent 3ob:freq parameter set of Elstner's group, excellent agreement with TD-DFT calculations using local functionals was achieved.

  11. Adaptive Model-Based Mine Detection/Localization using Noisy Laser Doppler Vibration Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, E J; Xiang, N; Candy, J V

    2009-04-06

    The acoustic detection of buried mines is hampered by the fact that at the frequencies required for obtaining useful penetration, the energy is quickly absorbed by the ground. A recent approach which avoids this problem, is to excite the ground with a high-level low frequency sound, which excites low frequency resonances in the mine. These resonances cause a low-level vibration on the surface which can be detected by a Laser Doppler Vibrometer. This paper presents a method of quickly and efficiently detecting these vibrations by sensing a change in the statistics of the signal when the mine is present. Results based on real data are shown.

  12. Vibrationally resolved UV/Vis spectroscopy with time-dependent density functional based tight binding

    OpenAIRE

    Rüger, Robert; Niehaus, Thomas; van Lenthe, Erik; Heine, Thomas; Visscher, Lucas

    2016-01-01

    We report a time-dependent density functional based tight-binding (TD-DFTB) scheme for the calculation of UV/Vis spectra, explicitly taking into account the excitation of nuclear vibrations via the adiabatic Hessian Franck-Condon (AH|FC) method with a harmonic approximation for the nuclear wavefunction. The theory of vibrationally resolved UV/Vis spectroscopy is first summarized from the viewpoint of TD-DFTB. The method is benchmarked against time-dependent density functional theory (TD-DFT) ...

  13. Design and Vibration Control of Safe Robot Arm with MR-Based Passive Compliant Joint

    Science.gov (United States)

    Yun, Seung-Kook; Yoon, Seong-Sik; Kang, Sungchul; Kim, Munsang

    In this paper, vibration control of a safe arm with passive compliant joints and visco-elastic covering for a human-friendly service robot is presented. The passive compliant joint (PCJ) is designed to passively attenuate the applied force. The rotary spring gives the arm compliant property, and yet it can be a source of vibration. We use an input-preshaping method which is motivated by the input shaping technique (IST) based on impulse responses. Experiments prove that both of fast motion and force attenuation of the safe arm can be achieved.

  14. Output Characteristics of Photoelectric Slip Sensor Based on Micro-vibration Detection

    Institute of Scientific and Technical Information of China (English)

    SHANG Zhen-dong; HAN Hong-biao; DENG Xiao-zhong; XU Xian-hong

    2007-01-01

    In order to achieve the manipulator's soft grasp function, the key is to have slip sensors with fine performance. Depending on the elastomer and photoelectric elements installed in the hand, the sensor transforms the slippage between the grasped object and the robot's hand to electric signal, thus the slippage can be detected. It will cause elastomers' micro-vibration when the object is slippage. Based on the vibration theory, dynamic theory, light intensity theory and elastic deformation theory, derived is the conclusion that the object's slippage acceleration relativing to the robot's hand has linear relationship with the photoelectric elements' output voltage's differential, and then the model for slippage distinguishing is set up.

  15. Elaboration of an implementation approach of a condition-based maintenance through vibration analysis

    Directory of Open Access Journals (Sweden)

    Semma El Mehdi

    2015-01-01

    Full Text Available Vibration analysis is a powerful and widely used tool in industry for monitoring rotating machinery. Despite the possibilities offered by the measuring equipment of vibration through technological progress, companies which practice Vibration Based Analysis (VBM show performance below expectations in terms of machine availability. Our duty then is to develop an approach for the implementation of the VBM taking into consideration the keys to success and avoiding the causes of failure. We carried out an analysis of 30 years of practice of the VBM within a large Moroccan company in the chemical industry, through a collective approach called DCA (in French applied short diagnosis and a survey among national and international experts in the field of the VBM. The synthesis of these studies has led us to propose a comprehensive and structured approach that comes in 5 phases: inventory, feasibility studies, preparation phase, implementation phase, evaluation and improvement phase.

  16. Homogeneity Analysis of a MEMS-based PZT Thick Film Vibration Energy Harvester Manufacturing Process

    DEFF Research Database (Denmark)

    Lei, Anders; Xu, Ruichao; Borregaard, Louise M.

    2012-01-01

    This paper presents a homogeneity analysis of a high yield wafer scale fabrication of MEMS-based unimorph silicon/PZT thick film vibration energy harvesters aimed towards vibration sources with peak vibrations in the range of around 300Hz. A wafer with a yield of 91% (41/45 devices) has been...... indicating that the main variation in open circuit voltage performance is caused by varying quality factor. The average resonant frequency was measured to 333Hz with a standard variation of 9.8Hz and a harvesting bandwidth of 5-10Hz. A maximum power output of 39.3μW was achieved at 1g for the best performing...

  17. Energy harvesting from coherent resonance of horizontal vibration of beam excited by vertical base motion

    Energy Technology Data Exchange (ETDEWEB)

    Lan, C. B.; Qin, W. Y. [Department of Engineering Mechanics, Northwestern Polytechnical University, Xi' an 710072 (China)

    2014-09-15

    This letter investigates the energy harvesting from the horizontal coherent resonance of a vertical cantilever beam subjected to the vertical base excitation. The potential energy of the system has two symmetric potential wells. So, under vertical excitation, the system can jump between two potential wells, which will lead to the large vibration in horizontal direction. Two piezoelectric patches are pasted to harvest the energy. From experiment, it is found that the vertical excitation can make the beam turn to be bistable. The system can transform vertical vibration into horizontal vibration of low frequency when excited by harmonic motion. The horizontal coherence resonance can be observed when excited by a vertical white noise. The corresponding output voltages of piezoelectric films reach high values.

  18. The correction of vibration in frequency scanning interferometry based absolute distance measurement system for dynamic measurements

    Science.gov (United States)

    Lu, Cheng; Liu, Guodong; Liu, Bingguo; Chen, Fengdong; Zhuang, Zhitao; Xu, Xinke; Gan, Yu

    2015-10-01

    Absolute distance measurement systems are of significant interest in the field of metrology, which could improve the manufacturing efficiency and accuracy of large assemblies in fields such as aircraft construction, automotive engineering, and the production of modern windmill blades. Frequency scanning interferometry demonstrates noticeable advantages as an absolute distance measurement system which has a high precision and doesn't depend on a cooperative target. In this paper , the influence of inevitable vibration in the frequency scanning interferometry based absolute distance measurement system is analyzed. The distance spectrum is broadened as the existence of Doppler effect caused by vibration, which will bring in a measurement error more than 103 times bigger than the changes of optical path difference. In order to decrease the influence of vibration, the changes of the optical path difference are monitored by a frequency stabilized laser, which runs parallel to the frequency scanning interferometry. The experiment has verified the effectiveness of this method.

  19. Harmonic-resonator-based triboelectric nanogenerator as a sustainable power source and a self-powered active vibration sensor.

    Science.gov (United States)

    Chen, Jun; Zhu, Guang; Yang, Weiqing; Jing, Qingshen; Bai, Peng; Yang, Ya; Hou, Te-Chien; Wang, Zhong Lin

    2013-11-13

    A harmonic-resonator-based triboelectric nanogenerator (TENG) is presented as a sustainable power source and an active vibration sensor. It can effectively respond to vibration frequencies ranging from 2 to 200 Hz with a considerably wide working bandwidth of 13.4 Hz. This work not only presents a new principle in the field of vibration energy harvesting but also greatly expands the applicability of TENGs.

  20. The Qualitative Research Method of Dynamics Vibration of a Washing Machine Based on Riccati Equation

    Directory of Open Access Journals (Sweden)

    Sergey P. Petrosov

    2012-09-01

    Full Text Available The accurate method for finding the common solutions of weakly interconnected system of nonhomogeneous differential equations with variable coefficients based on Riccati Equation was developed. This method describes the dynamics of vibration of the suspension drum type of a washing machine in spin mode.

  1. Energy-autonomous wireless vibration sensor for condition-based maintenance of machinery

    NARCIS (Netherlands)

    Wang, Z.; Bouwens, F.; Vullers, R.; Petré, F.; Devos, S.

    2011-01-01

    This paper addresses the development of an energy-autonomous wireless vibration sensor for condition-based monitoring of machinery. Such technology plays an increasingly important role in modern manufacturing industry. In this work, energy harvesting is realized by resorting to a custom designed the

  2. Nonlinear Dynamic Behaviors of Rotated Blades with Small Breathing Cracks Based on Vibration Power Flow Analysis

    Directory of Open Access Journals (Sweden)

    Hailong Xu

    2016-01-01

    Full Text Available Rotated blades are key mechanical components in turbomachinery and high cycle fatigues often induce blade cracks. Accurate detection of small cracks in rotated blades is very significant for safety, reliability, and availability. In nature, a breathing crack model is fit for a small crack in a rotated blade rather than other models. However, traditional vibration displacements-based methods are less sensitive to nonlinear characteristics due to small breathing cracks. In order to solve this problem, vibration power flow analysis (VPFA is proposed to analyze nonlinear dynamic behaviors of rotated blades with small breathing cracks in this paper. Firstly, local flexibility due to a crack is derived and then time-varying dynamic model of the rotated blade with a small breathing crack is built. Based on it, the corresponding vibration power flow model is presented. Finally, VPFA-based numerical simulations are done to validate nonlinear behaviors of the cracked blade. The results demonstrate that nonlinear behaviors of a crack can be enhanced by power flow analysis and VPFA is more sensitive to a small breathing crack than displacements-based vibration analysis. Bifurcations will occur due to breathing cracks and subharmonic resonance factors can be defined to identify breathing cracks. Thus the proposed method can provide a promising way for detecting and predicting small breathing cracks in rotated blades.

  3. Energy-autonomous wireless vibration sensor for condition-based maintenance of machinery

    NARCIS (Netherlands)

    Wang, Z.; Bouwens, F.; Vullers, R.; Petré, F.; Devos, S.

    2011-01-01

    This paper addresses the development of an energy-autonomous wireless vibration sensor for condition-based monitoring of machinery. Such technology plays an increasingly important role in modern manufacturing industry. In this work, energy harvesting is realized by resorting to a custom designed

  4. Vibration based structural health monitoring in fibre reinforced composites employing the modal strain energy method

    NARCIS (Netherlands)

    Loendersloot, Richard; Ooijevaar, Ted; Warnet, Laurent; Akkerman, Remko; Boer, de André; Meguid, S.A.; Gomes, J.F.S.

    2009-01-01

    The feasibility of a vibration based damage identification method is investigated. The Modal Strain Energy method is applied to a T–beam structure. The dynamic response of an intact structure and a damaged, delaminated structure is analysed employing a commercially available Finite Element package.

  5. A finite element-based perturbation method for nonlinear free vibration analysis of composite cylindrical shells

    NARCIS (Netherlands)

    Rahman, T.; Jansen, E.L.; Tiso, P.

    2011-01-01

    In this paper, a finite element-based approach for nonlinear vibration analysis of shell structures is presented. The approach makes use of a perturbation method that gives an approximation for the amplitude-frequency relation of the structure. The method is formulated using a functional notation an

  6. Application of the heterogeneous (HG) blankets for controlling the base structure vibration levels

    Science.gov (United States)

    Gautam, Ashwini; Fuller, C. R.; Carneal, James

    2005-09-01

    This work presents an extensive analysis of the properties of the heterogeneous blankets (HGs) and their effectiveness in controlling the vibration of the base structures. The HG blankets act as a distributed vibration absorbers consisting of mass inhomogeneities inside a layer of porous media (acoustic foam). To asses the effectiveness of these HG blankets in controlling the vibration of the base structure (plate), detailed finite element (FE) models of the foam, the HG blanket, and the plate have been developed. The foam has been dicretized using the eight node hexahedral elements. The HG blanket model consists of the foam model with point masses attached to the nodes of the elements. The structural (plate) domain is discretized using four node rectangular plate elements. Each of the FE models has been individually validated by comparing the numerical results with their respective analytical and experimental results. The structural and the HG blanket FE models were then combined into a larger FE model comprised of a base plate with the HG treatment on its surface. The results from this numerical model have shown that there is a significant reduction in the vibration levels of the base plate due to the HG treatment on it.

  7. A finite element-based perturbation method for nonlinear free vibration analysis of composite cylindrical shells

    NARCIS (Netherlands)

    Rahman, T.; Jansen, E.L.; Tiso, P.

    2011-01-01

    In this paper, a finite element-based approach for nonlinear vibration analysis of shell structures is presented. The approach makes use of a perturbation method that gives an approximation for the amplitude-frequency relation of the structure. The method is formulated using a functional notation

  8. Elliptic hole abrasive belt chamfer machine tool%椭圆孔砂带倒角机床

    Institute of Scientific and Technical Information of China (English)

    王友林; 姜英

    2012-01-01

    From the structure and working principle, etc, this paper introduced a machine tool that machining elliptic hole on small end bevel face of link, using ductile deformation of abrasive belt method to substitute the additional movement of cutting tool or the workpiece along the long axis of elliptic hole, the edge of elliptic hole is removed by grinding material on abrasive belt under the influence of movement and pressure , obtain a chamfer plane, achieve machining of elliptic hole chamfer.%从结构、工作原理等方面介绍了一种用于连杆小头斜端面上的椭圆孔的倒角加工机床,利用砂带的挠性变形替代加工中刀具或工件沿椭圆的长轴移动的附加运动,工件端面上椭圆孔的棱边在砂带的压力与运动作用下被砂带上的磨料切除,形成倒角平面,实现了椭圆形孔的倒角加工.

  9. Pattern Formation in a Vibrated Granular Layer on an Inclined Base

    Institute of Scientific and Technical Information of China (English)

    SHI Xiao-Dong; MIAO Guo-Qing

    2008-01-01

    We carry out the simulations of pattern formation in a two-dimensional vibrated granular layer on an inclined base by molecular dynamics.It is found that the maximum amplitude of the pattern is greater at the lower part than at the higher part of the base,and is proportional to the thickness of the layer.Meanwhile,the wavelength varies non-monotonically as the inclined angle of the base is increased.

  10. The interior working mechanism and temperature characteristics of a fluid based micro-vibration isolator

    Science.gov (United States)

    Wang, Jie; Zhao, Shougen; Wu, Dafang; Jing, Xingjian

    2016-01-01

    Micro-vibration isolation is a hot topic in spacecraft vibration control, and fluid based vibration isolators alternatively provide a good and reliable solution to this challenging issue. In this paper, a novel fluid based micro-vibration isolator (FBMVI) is investigated. According to its inherent working principle and deformation pattern, the generation mechanisms of the damping and stiffness characteristics are derived, which are nonlinear functions of the environmental temperature. Then a lumped parameter model which is expressed by the physical design parameters (PDPs) is constructed, and the corresponding performance objective indices (POIs) are also obtained by applying the equivalence of mechanical impedance. Based on the finite element analysis of the internal damping component, a single variable method is further adopted to carry out the parametric study, and the influences of each PDP on the POIs are analyzed in details. Finally, experiments are conducted to identify the variation of fluid bulk modulus with the outside environmental temperature, and to validate the performance of the isolator under different temperature environments. The tested results show great consistence compared with the predicted tendencies of the parametric study. The results of this study can provide a very useful insight into and/or an important guidance for the design and application of this type of FBMVIs in engineering practice.

  11. Molecular Structure, NMR, HOMO, LUMO, and Vibrational Analysis of O-Anisic Acid and Anisic Acid Based on DFT Calculations

    Directory of Open Access Journals (Sweden)

    R. Mathammal

    2013-01-01

    Full Text Available This work deals with the vibrational spectroscopy of O-Anisic acid (OAA and Anisic acid (AA. The fundamental vibrational frequencies and intensity of vibrational bands were evaluated using density functional theory (DFT with standard B3LYP/6-31G** method and basis set combinations. The vibrational spectra were interpreted, with the aid of normal coordinate analysis based on a scaled quantum mechanical force field. The infrared and Raman spectra were also predicted from the calculated intensities. The effects of carbonyl and methyl substitutions on the structure and vibrational frequencies have been investigated. Comparison of simulated spectra with the experimental spectra provides important information about the ability of the computational method to describe the vibrational modes. The 13C and 1H NMR chemical shifts of the DFA and CA molecules were calculated using the gauge-invariant-atomic orbital (GIAO method in DMSO solution using IEF-PCM model and compared with experimental data.

  12. Real time identification of the internal combustion engine combustion parameters based on the vibration velocity signal

    Science.gov (United States)

    Zhao, Xiuliang; Cheng, Yong; Wang, Limei; Ji, Shaobo

    2017-03-01

    Accurate combustion parameters are the foundations of effective closed-loop control of engine combustion process. Some combustion parameters, including the start of combustion, the location of peak pressure, the maximum pressure rise rate and its location, can be identified from the engine block vibration signals. These signals often include non-combustion related contributions, which limit the prompt acquisition of the combustion parameters computationally. The main component in these non-combustion related contributions is considered to be caused by the reciprocating inertia force excitation (RIFE) of engine crank train. A mathematical model is established to describe the response of the RIFE. The parameters of the model are recognized with a pattern recognition algorithm, and the response of the RIFE is predicted and then the related contributions are removed from the measured vibration velocity signals. The combustion parameters are extracted from the feature points of the renovated vibration velocity signals. There are angle deviations between the feature points in the vibration velocity signals and those in the cylinder pressure signals. For the start of combustion, a system bias is adopted to correct the deviation and the error bound of the predicted parameters is within 1.1°. To predict the location of the maximum pressure rise rate and the location of the peak pressure, algorithms based on the proportion of high frequency components in the vibration velocity signals are introduced. Tests results show that the two parameters are able to be predicted within 0.7° and 0.8° error bound respectively. The increase from the knee point preceding the peak value point to the peak value in the vibration velocity signals is used to predict the value of the maximum pressure rise rate. Finally, a monitoring frame work is inferred to realize the combustion parameters prediction. Satisfactory prediction for combustion parameters in successive cycles is achieved, which

  13. 数控机床三维空间误差建模及补偿技术研究%Research on Compensation Technique for 3-Dimension Volumetric Errors of CNC Machine Tools

    Institute of Scientific and Technical Information of China (English)

    朱赤洲; 陈蔚芳; 赵鹏; 刘明灯

    2012-01-01

    3-Dimension volumetric errors of CNC machine tools will cause a decrease in machining quality. To overcome this problem, ensure the machining accuracy, two compensation strategies based on error modeling by using multi-body system theory are proposed. One is offline compensation, the other is embedded compensation. Offline compensation, a kind of correction compensation based on NC program, realizes the compensation of 3-Dimension volumetric errors of CNC machine tools by mapping the errors to NC program and modifying the NC program. Embedded compensation is a kind of online compensation based on CNC system, and it realizes the compensation by modifying the data flow of CNC system. This method is on the foundation of the amalgamation of CNC system and 3-Dimension volumetric errors model. Results from experiments show that both of the two compensation strategies significantly improve the precision of CNC machine tools and not affect the machine reliability.%为了提高数控机床的加工精度,解决由机床三维空间误差引起的工件加工质量降低的问题,在研究多体系统理论误差建模技术的基础上,提出离线补偿和嵌入式补偿两种补偿策略.离线补偿是基于数控加工程序的修正补偿,将机床三维空间误差映射到数控加工程序,通过修改加工程序实现对机床的三维空间误差补偿;嵌入式补偿是基于数控系统的在线补偿,将机床三维空间误差融合到数控系统中,通过修正数控系统中的数据流实现对机床的三维空间误差补偿.实验表明,在不影响机床可靠性的前提下,两种补偿策略均显著提高了数控机床的加工精度.

  14. Structural Modifications for Torsional Vibration Control of Shafting Systems Based on Torsional Receptances

    Directory of Open Access Journals (Sweden)

    Zihao Liu

    2016-01-01

    Full Text Available Torsional vibration of shafts is a very important problem in engineering, in particular in ship engines and aeroengines. Due to their high levels of integration and complexity, it is hard to get their accurate structural data or accurate modal data. This lack of data is unhelpful to vibration control in the form of structural modifications. Besides, many parts in shaft systems are not allowed to be modified such as rotary inertia of a pump or an engine, which is designed for achieving certain functions. This paper presents a strategy for torsional vibration control of shaft systems in the form of structural modifications based on receptances, which does not need analytical or modal models of the systems under investigation. It only needs the torsional receptances of the system, which can be obtained by testing simple auxiliary structure attached to relevant locations of the shaft system and using the finite element model (FEM of the simple structure. An optimization problem is constructed to determine the required structural modifications, based on the actual requirements of modal frequencies and mode shapes. A numerical experiment is set up and the influence of several system parameters is analysed. Several scenarios of constraints in practice are considered. The numerical simulation results demonstrate the effectiveness of this method and its feasibility in solving torsional vibration problems in practice.

  15. 高精密机床主轴回转误差在线测试系统%Spindle rotary error online test system of high precision machine tool

    Institute of Scientific and Technical Information of China (English)

    周继昆; 张荣; 凌明祥; 张毅

    2016-01-01

    To realize real-time online measurement of spindle rotary error of high precision machine tool,based on the mechanical structure of machine tool,the standard ball and external reference measurement method was used to measure the radial displacement of the spindle indirectly and three-point method (error separation algorithm) was used to separate the spindle roundness error and rotary error so as to obtain the pure rotary error. According to the proposed test method, the hardware part of test system was created based on PXI bus data acquisition technology and the PXI external clock synchronization collection card was used to realize the equiangular and synchronous collection of spindle radial displacement information. Online test software was developed in LabVIEW development environment,with which the spindle rotary error can be separated on line. A machine tool was tested online with the developed test system and the test results showed that the developed test system can separate pure spindle rotary error from radial displacement information online with a high accuracy.%为实现对高精度机床主轴回转误差的在线实时测量,根据机床机械结构特点,采用标准球及外基准测量方法间接对机床主轴径向位移进行测量,并利用三点法误差分离算法将主轴圆度误差与回转误差分离,得到纯回转误差。依据所提出的测试方法,基于PXI总线数据采集技术建立测试系统硬件部分,并利用PXI外部时钟同步采集卡实现主轴径向位移信息的等角度同步采样;在LabVIEW开发环境下,开发在线测试软件,对回转误差进行在线分离。利用该系统对某机床进行在线测试,测试结果表明,测试系统可以在线将机床主轴纯回转误差从径向位移信息中分离出来,并达到较高的测试准确度。

  16. Dual-wavelength speckle-based SI-POF sensor for frequency detection and localization of remote vibrations

    Science.gov (United States)

    Pinzón, P. J.; Montero, D. S.; Tapetado, A.; Torres, J. C.; Vázquez, C.

    2016-05-01

    A novel speckle-based method for sensing frequency vibration is demonstrated in a reflective configuration. By employing a visible dual-wavelength approach it is also possible to determine the relative spatial location of the vibrations along a plastic optical fiber lead of 8 m in a distributed scheme.

  17. Hydrogen release reactions of Al-based complex hydrides enhanced by vibrational dynamics and valences of metal cations.

    Science.gov (United States)

    Sato, T; Ramirez-Cuesta, A J; Daemen, L; Cheng, Y-Q; Tomiyasu, K; Takagi, S; Orimo, S

    2016-09-27

    Hydrogen release from Al-based complex hydrides composed of metal cation(s) and [AlH4](-) was investigated using inelastic neutron scattering viewed from vibrational dynamics. The hydrogen release followed the softening of translational and [AlH4](-) librational modes, which was enhanced by vibrational dynamics and the valence(s) of the metal cation(s).

  18. Engraving machine tool CNC

    OpenAIRE

    Moreira, André Filipe Leal

    2015-01-01

    Dissertação de mestrado em Engenharia Mecatrónica No panorama atual, as novas tecnologias aplicadas às máquinas ferramentas permitiram um desenvolvimento excecional. As máquinas CNC, Controlo Numérico Computadorizado, do inglês “computer numerical control”, vieram revolucionar a indústria, permitindo maior velocidade, repetibilidade e precisão. É pretendido nesta dissertação o desenvolvimento de uma máquina de comando numérico de pequenas dimensões. O projeto desenvolvido fo...

  19. State-of-the-art in vibration-based electrostatic energy harvesting

    Science.gov (United States)

    Ullah Khan, Farid; Usman Qadir, Muhammad

    2016-10-01

    Recently, embedded systems and wireless sensor nodes have been gaining importance. For operating these devices several vibration-based energy harvesters have been successfully developed and reported, such as piezoelectric, electromagnetic, and electrostatic energy harvesters (EEHs). This paper presents the state-of-the-art in the field of vibration-based EEHs. Mainly, two types of EEHs, electret-free and electret-based, are reported in the literature. The developed EEHs are mostly of the centimeter scale. These energy harvesters, with resonant frequencies ranging from 2 Hz to 1.7 kHz, when subjected to excitation on the order of 0.25 g to 14.2 g, generate power that ranges from 0.46 nW to 2.1 mW.

  20. Research on Magnetic Levitation Operation Mechanism of Permanent Magnet Linear Motor in CNC Machine Tool%数控机床永磁直线电动机磁悬浮运行机制研究

    Institute of Scientific and Technical Information of China (English)

    蓝益鹏; 张振兴

    2012-01-01

    为实现数控机床永磁直线同步电动机的磁悬浮运行,须对电动机的电磁推力和悬浮力进行实时控制.电磁推力和悬浮力的计算是数控机床磁悬浮永磁直线同步电动机设计及控制的基础.根据数控机床永磁直线同步电动机的磁悬浮运行机制,推导出电动机的电磁推力和悬浮力与电流之间关系的数学模型.并用Ansoft对电磁推力和悬浮力进行有限元分析,将解析计算结果与Ansoft的计算结果进行比较,验证了数学模型的有效性与正确性,为数控机床永磁直线同步电动机磁悬浮控制系统的分析与设计提供依据.%Real-time control to electromagnetic thrust and levitation force is necessary in order to realize magnetic levitation stable operation of the permanent magnet linear motor in CNC machine tool. The calculations of electromagnetic thrust and levitation force are the foundation of magnetic levitalion permanent magnet linear synchronous motor design and control. Mathematical models of electromagnetic thrust and magnetic levitation force were derived based on the operating principle of double winding levitation permanent magnet linear synchronous motor in CNC machine tool. Further more, finite element analyses of electromagnetic thrust and levitation force were completed by Ansoft. Trie comparison between calculation results and simulation results confirms the correctness and effectiveness of the proposed mathematical model, which provides a basis for analysis and design of permanent magnet linear motor magnetic levitation control system in CNC machine tool.

  1. Analysis of a Lorentz force based vibration exciter using permanent magnets mounted on a piezoelectric stack

    Indian Academy of Sciences (India)

    Arghya Nandi; Sumanta Neogy; Sankha Bhaduri

    2011-02-01

    This work presents performance analysis of a Lorentz force based noncontact vibration exciter by mounting a couple of permanent magnets on a piezoelectric stack. A conductor is attached to the structure to be excited and is placed midway between unlike poles of a couple of permanent magnets. The permanent magnets are placed on a piezoelectric stack. This stack, because of its nano-positioning capabilities, can impart an accurate and adjustable harmonic vibratory motion to the couple of permanent magnets. The piezoelectric stack, because of its high stiffness remains uncoupled with the dynamics of the structure. Due to the relative motion between the magnets and the conductor, Lorentz force is generated within the conductor. This Lorentz force is responsible for vibration of the structure in a plane parallel to the pole faces of the magnets. This keeps the magnetic field almost independent of the vibration of the structure and the chance of the structure hitting the magnet during large vibration is totally eliminated. If the amplitude of displacement of the stack is kept constant, the non-contact excitation force in this exciter remains proportional to the excitation frequency. Though use of this exciter eliminates mass (apart from that of the conductor attached to the structure) and stiffness coupling, a known damping term gets added to that of the excited structure.

  2. Comparing AFM cantilever stiffness measured using the thermal vibration and the improved thermal vibration methods with that of an SI traceable method based on MEMS

    Science.gov (United States)

    Brand, Uwe; Gao, Sai; Engl, Wolfgang; Sulzbach, Thomas; Stahl, Stefan W.; Milles, Lukas F.; Nesterov, Vladimir; Li, Zhi

    2017-03-01

    PTB has developed a new contact based method for the traceable calibration of the normal stiffness of AFM cantilevers in the range from 0.03 N m‑1 to 300 N m‑1 to the SI units based on micro-electro-mechanical system (MEMS) actuators. This method is evaluated by comparing the measured cantilever stiffness with that measured by PTB’s new primary nanonewton force facility and by PTB’s microforce measuring device. The MEMS system was used to calibrate the stiffness of cantilevers in two case studies. One set of cantilevers for applications in biophysics was calibrated using the well-known thermal vibration method and the second set of cantilevers was calibrated by a cantilever manufacturer who applied an improved thermal vibration method based on calibrated reference cantilevers for the cantilever stiffness calibration. The comparison revealed a stiffness deviation of  +7.7% for the cantilevers calibrated using the thermal vibration method and a deviation of  +6.9% for the stiffnesses of the cantilevers calibrated using the improved thermal vibration method.

  3. Flextensional fiber Bragg grating-based accelerometer for low frequency vibration measurement

    Institute of Scientific and Technical Information of China (English)

    Jinghua Zhang; Xueguang Qiao; Manli Hu; Zhongyao Feng; Hong Gao; Yang Yang; Rui Zhou

    2011-01-01

    @@ The intelligent structural health monitoring method,which uses a fiber Bragg grating(FBG)sensor,is a new approach in the field of civil engineering.However,it lacks a reliable FBG-based accelerometer for taking structural low frequency vibration measurements.In this letter,a flextensional FBG-based accelerometer is proposed and demonstrated.The experimental results indicate that the natural frequency of the developed accelerometer is 16.7 Hz,with a high sensitivity of 410.7 pm/g.In addition,it has a broad and flat response over low frequencies ranging from 1 to 10 Hz.The natural frequency and sensitivity of the accelerometer can be tuned by adding mass to tailor the sensor performance to specific applications.Experimental results are presented to demonstrate the good performance of the proposed FBG-based accelerometer.These results show that the proposed accelerometer is satisfactory for low frequency vibration measurements.%The intelligent structural health monitoring method, which uses a fiber Bragg grating {FBG} sensor, ie a new approach in the field of civil engineering. However, it lacks a reliable FBG-based accelerometer for taking structural low frequency vibration measurements. In this letter, a flextensional FBG-based accelerometer is proposed and demonstrated. The experimental results indicate that the natural frequency of the developed accelerometer is 16.7 Hz, with a high sensitivity of 410.7 pm/g. In addition, it has a broad and flat response over low frequencies ranging from 1 to 10 Hz. The natural frequency and sensitivity of the accelerometer can be tuned by adding mass to tailor the sensor performance to specific applications. Experimental results are presented to demonstrate the good performance of the proposed FBG-based accelerometer. These results show that the proposed accelerometer is satisfactory for low frequency vibration measurements.

  4. Study on Properties of Cast Iron Materials for Machine Tool%机床用铸铁材料的性能研究

    Institute of Scientific and Technical Information of China (English)

    符特

    2013-01-01

    综述了机床用铸铁(灰铸铁、球墨铸铁和蠕墨铸铁)材料的性能.分析了化学成分,力学佳能,应用领域和失效方式,并且介绍了提高其耐磨性的机理研究和工艺方法等方面取得的进展.这能为机床选材和制造提供依据.%The properties of cast iron, such as gray cast iron, vermicular cast iron and spheroidal graphite cast iron for machine tool, were reviewed. The chemical composition, mechanical property, application and failure mode were analyzed. And the recent progress of the mechanism research and process method about improving its wear resistance was introduced. This can provide the basis for choosing materials and manufacturing of machine tool.

  5. 高性能组合机床和高生产率加工中心%The High Performance Combination Machine Tools and High Productivity Machining Center

    Institute of Scientific and Technical Information of China (English)

    卫美红; 张曙

    2014-01-01

    以汽车关键零部件制造为例,分析了机械制造业中高效率与高柔性之间的矛盾和统一。介绍了国际上高性能组合机床及高生产率加工中心的应用和技术发展趋势,并指出将数控技术引入专用机床是化解这对矛盾的正确方向。%Taking the car'parts and components manufacturing as examples , it analyzes the contradiction and uni-ty between high efficient and flexible in machinery manufacture , introduces the application and development trend of international high performance combination machine tools and high productivity machining center , sug-gests basic strategy to introduce the numerical control technology into specialized machine tools .

  6. A piezoelectric vibration harvester based on clamped-guided beams

    NARCIS (Netherlands)

    Wang, Z.; Matova, S.; Elfrink, R.; Jambunathan, M.; Nooijer, C. de; Schaijk, R. van; Vullers, R.J.M.

    2012-01-01

    The paper addresses the design, modeling, fabrication and experimental results of a piezoelectric energy harvester based on clamped-guided beams. The design is featured by shorter mass displacement and higher reliability than cantilever beams. Two separate sets of capacitors allow exploiting both te

  7. Investigation of folded spring structures for vibration-based piezoelectric energy harvesting

    Science.gov (United States)

    Lueke, J.; Rezaei, M.; Moussa, W. A.

    2014-12-01

    This paper presents a fixed-fixed folded spring as an alternative elastic element for beam-based piezoelectric energy harvesting. In order to harvest energy from low frequency vibration in an optimal manner, the natural/operational frequencies of harvesters must be reduced to match low frequency input vibrations. Therefore, natural frequency reduction of vibration-based energy harvesters is critical to maximize output power at low operational frequency. The mechanical optimization of cantilever-based piezoelectric energy harvesters is limited by residual stress-based beam curling that produced through microfabrication adding additional mechanical stiffness to the system. The fixed-fixed folded spring structure presented in this paper allows for increased effective beam length and residual stress relaxation, without out of plane beam curling to further reducing the natural frequency. Multiple designs of folded spring energy harvesters are presented to demonstrate the effect of important design parameters. It is shown that the folded spring harvesters were capable of harvesting electricity at low natural frequencies, ranging from 45 Hz to 3667 Hz. Additionally, the harvesters were shown to be insensitive to microfabrication-based residual stress beam curling. The maximum power output achieved by the folded spring harvesters was 690.5 nW at 226.3 Hz for a single harvesting element of an array, with a PZT layer thickness of 0.24 μm. The work presented in this paper demonstrates that the fixed-fixed folded spring can be used as a viable structural element for low frequency piezoelectric energy harvesting to take advantage of ambient vibrations found in low frequency applications.

  8. Development of the Manufacturing Machine Tool for the Various Steering Knuckle Forks%多品种转向节叉加工机床的研制

    Institute of Scientific and Technical Information of China (English)

    栗全庆; 李明

    2015-01-01

    In the machine tool, new technology method and U drill were adopted to machine the hole of the parts of various steer⁃ing knuckle forks. Through the process of drilling and boring, the hole of the parts could reach the precision of the process of drilling➝expanding➝hinging➝boring. Because U drill was allowed to adopt higher cutting speed and feed, the machining time was greatly short⁃ened. Through technology analysis to these parts, the general layout and working cycle of the machine tool were expounded. The main structures and features of the machine tool were introduced. This machine tool has the characteristics of good rigidity, high precision and high efficiency.%介绍了加工多品种转向节叉零件的专用机床,采用新的工艺方法和U钻对零件的孔进行加工,通过钻➝镗工艺使孔达到钻➝扩➝铰➝镗工艺的精度。由于U钻允许采用较高的切削速度和进给量,从而大大缩短了加工时间。通过对零件进行工艺分析,阐述了机床的总体布局和工作循环,介绍了机床主要部件的结构及特点。该机床具有刚性好、精度高和效率高等特点。

  9. Evaluation of Eco-efficiency and Effect on Environment of Remanufacturing—— A Case Study of CNC-remanufacturing for Used Machining Tools

    Institute of Scientific and Technical Information of China (English)

    HU Zhong-xiang; SHI Xiao-jun; SHI Lei

    2005-01-01

    A case of remanufacturing used lathes via CNC technology is introduced, whose environmental and economic benefits are evaluated respectively. The results indicate that these environmental and economic benefits are remarkable, which are directly affected by remanufacturing design, more than 90% materials in used lathes are reused. Finally, the causes of economic and environmental benefits of remanufacturing machine tools are put forward. The remanufacturing design method, implementation procedure, and evaluation method of economic and environmental benefits presented are helpful for other equipment remanufacturing.

  10. A search for optimal parameters of resonance circuits ensuring damping of electroelastic structure vibrations based on the solution of natural vibration problem

    Science.gov (United States)

    Oshmarin, D.; Sevodina, N.; Iurlov, M.; Iurlova, N.

    2017-06-01

    In this paper, with the aim of providing passive control of structure vibrations a new approach has been proposed for selecting optimal parameters of external electric shunt circuits connected to piezoelectric elements located on the surface of the structure. The approach is based on the mathematical formulation of the natural vibration problem. The results of solution of this problem are the complex eigenfrequencies, the real part of which represents the vibration frequency and the imaginary part corresponds to the damping ratio, characterizing the rate of damping. A criterion of search for optimal parameters of the external passive shunt circuits, which can provide the system with desired dissipative properties, has been derived based on the analysis of responses of the real and imaginary parts of different complex eigenfrequencies to changes in the values of the parameters of the electric circuit. The efficiency of this approach has been verified in the context of natural vibration problem of rigidly clamped plate and semi-cylindrical shell, which is solved for series-connected and parallel -connected external resonance (consisting of resistive and inductive elements) R-L circuits. It has been shown that at lower (more energy-intensive) frequencies, a series-connected external circuit has the advantage of providing lower values of the circuit parameters, which renders it more attractive in terms of practical applications.

  11. Carbon Nanotube-Based Nanomechanical Sensor: Theoretical Analysis of Mechanical and Vibrational Properties

    Directory of Open Access Journals (Sweden)

    Toshiaki Natsuki

    2017-08-01

    Full Text Available This paper reviews the recent research of carbon nanotubes (CNTs used as nanomechanical sensing elements based mainly on theoretical models. CNTs have demonstrated considerable potential as nanomechanical mass sensor and atomic force microscope (AFM tips. The mechanical and vibrational characteristics of CNTs are introduced to the readers. The effects of main parameters of CNTs, such as dimensions, layer number, and boundary conditions on the performance characteristics are investigated and discussed. It is hoped that this review provides knowledge on the application of CNTs as nanomechanical sensors and computational methods for predicting their properties. Their theoretical studies based on the mechanical properties such as buckling strength and vibration frequency would give a useful reference for designing CNTs as nanomechanical mass sensor and AFM probes.

  12. Advances in simulated modeling of vibration systems based on computational intelligence

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Computational intelligence is the computational simulation of the bio-intelligence, which includes artificial neural networks, fuzzy systems and evolutionary computations. This article summarizes the state of the art in the field of simulated modeling of vibration systems using methods of computational intelligence, based on some relevant subjects and the authors' own research work. First, contributions to the applications of computational intelligence to the identification of nonlinear characteristics of packaging are reviewed. Subsequently, applications of the newly developed training algorithms for feedforward neural networks to the identification of restoring forces in multi-degree-of-freedom nonlinear systems are discussed. Finally, the neural-network-based method of model reduction for the dynamic simulation of microelectromechanical systems (MEMS) using generalized Hebbian algorithm (GHA) and robust GHA is outlined. The prospects of the simulated modeling of vibration systems using techniques of computational intelligence are also indicated.

  13. Integrated vibration-based maintenance: an approach for continuous reduction in LCC. A case study

    Energy Technology Data Exchange (ETDEWEB)

    Najjar, B. [ER Konsult Utveckling AB, Vaexjoe (Sweden)

    1998-12-31

    The biggest thread in achieving and maintaining high equipment effectiveness can be stated as: whether the improved manufacturing processes capable of producing quality products at a competitive cost. The effect of a new vibration-based maintenance concept, called Total Quality Maintenance (TQMain), is introduced. It aims to make intensive use of the real-time data acquisition and analysis to detect causes behind product quality deviation and failures in machinery, and following defect development at an early stage to increase machine mean effective life and improve company`s economics. The effect of TQMain on LCC of machinery and company`s economics is discussed. A case study to reveal savings in maintenance cost when a vibration-based policy involved, is presented. Using TQMain, company`s economics can be improved effectively through continuous improvement of the technical and economic effectiveness of production processes. (orig.) 14 refs.

  14. Surface effects on the vibration behavior of flexoelectric nanobeams based on nonlocal elasticity theory

    Science.gov (United States)

    Ebrahimi, Farzad; Reza Barati, Mohammad

    2017-01-01

    In this research, vibration characteristics of a flexoelectric nanobeam in contact with Winkler-Pasternak foundation is investigated based on the nonlocal elasticity theory considering surface effects. This nonclassical nanobeam model contains flexoelectric effect to capture coupling of strain gradients and electrical polarizations. Moreover, the nonlocal elasticity theory is employed to study the nonlocal and long-range interactions between the particles. The present model can degenerate into the classical model if the nonlocal parameter, flexoelectric and surface effects are omitted. Hamilton's principle is employed to derive the governing equations and the related boundary conditions which are solved applying a Galerkin-based solution. Natural frequencies are verified with those of previous papers on nanobeams. It is illustrated that flexoelectricity, nonlocality, surface stresses, elastic foundation and boundary conditions affects considerably the vibration frequencies of piezoelectric nanobeams.

  15. Evaluation of the vehicle state with vibration-based diagnostics methods

    Science.gov (United States)

    Gai, V. E.; Polyakov, I. V.; Krasheninnikov, M. S.; Koshurina, A. A.; Dorofeev, R. A.

    2017-02-01

    Timely detection of a trouble in the mechanisms work is a guarantee of the stable operation of the entire machine complex. It allows minimizing unexpected losses, and avoiding any injuries inflicted on working people. The solution of the problem is the most important for vehicles and machines, working in remote areas of the infrastructure. All-terrain vehicles can be referred to such type of transport. The potential object of application of the described methodology is the multipurpose rotary-screw amphibious vehicle for rescue; reconnaissance; transport and technological operations. At the present time, there is no information on the use of these kinds of systems in ground-based vehicles. The present paper is devoted to the state estimation of a mechanism based on the analysis of vibration signals produced by the mechanism, in particular, the vibration signals of rolling bearings. The theory of active perception was used for the solution of the problem of the state estimation.

  16. Measuring the resonant vibration of a sessile droplet using MEMS based cantilevers

    Science.gov (United States)

    Nguyen, Thanh-Vinh; Matsumoto, Kiyoshi; Shimoyama, Isao

    2015-11-01

    We directly measure the normal force distribution on the contact area during the 1st mode resonant vibration of a droplet using an array of MEMS based cantilever. The measurement result shows that the normal force change is the largest at the periphery of the contact area. The ratio between the amplitude of the normal force change at the periphery of the contact area over that at the center of the contact area was approximately 20 times, in the case of 1.8 μL water droplet whose equilibrium contact angle is 140 degrees. We also demonstrate a method to estimate viscosity based on the measurement of the droplet vibration using MEMS cantilevers. The proposed method is able to estimate viscosity using less than 3 μL sample and has a simple operating principle. We believe that this method is suitable for point-of-care testing and characterization of chemical and biological solutions.

  17. A vibration-based health monitoring program for a large and seismically vulnerable masonry dome

    Science.gov (United States)

    Pecorelli, M. L.; Ceravolo, R.; De Lucia, G.; Epicoco, R.

    2017-05-01

    Vibration-based health monitoring of monumental structures must rely on efficient and, as far as possible, automatic modal analysis procedures. Relatively low excitation energy provided by traffic, wind and other sources is usually sufficient to detect structural changes, as those produced by earthquakes and extreme events. Above all, in-operation modal analysis is a non-invasive diagnostic technique that can support optimal strategies for the preservation of architectural heritage, especially if complemented by model-driven procedures. In this paper, the preliminary steps towards a fully automated vibration-based monitoring of the world’s largest masonry oval dome (internal axes of 37.23 by 24.89 m) are presented. More specifically, the paper reports on signal treatment operations conducted to set up the permanent dynamic monitoring system of the dome and to realise a robust automatic identification procedure. Preliminary considerations on the effects of temperature on dynamic parameters are finally reported.

  18. 对数控机床在线测量进行误差分析%Error Analysis of CNC Machine Tools Online Measurement

    Institute of Scientific and Technical Information of China (English)

    于佃清

    2015-01-01

    The paper split CNC machine tools online measurement system into 2 parts for optimizing online measurement system, CNC machine tools body and probe measurement system. According to the analysis of the structure and working principle of CNC machine tools online system, the structure composition and measurement principle of the probe system were analysed, then the error sources and characters as well.%本文为优化数控机床在线测量系统,将数控机床在线测量系统拆分为数控机床本体和测头测量系统两部分,通过对数控机床在线系统的结构组成和工作原理分析,再对测头系统的结构组成及测量原理分析,然后对其开展深层次的分析误差来源及性质.以期能够为数控机床在线测量有效优化提供有价值的参考依据.

  19. Study on maintenance of CNC machine tool used in lean manufacturing%精益生产下的数控机床维护维修研究

    Institute of Scientific and Technical Information of China (English)

    李攀峰; 高云婷

    2011-01-01

    The paper studied the distribution of NC machine tool failure, discussed the causes and preventive measures, analyzed the contradiction between the need of lean manufacturing system and the maintenance of CNC machine tools.Then, a basic method to solve this problem was given by author.Finally, it pointed out that the key for implementation of lean production management is to explore the effective way in maintenance of CNC machine tools by enterprise itself.%介绍了数控机床常见故障的分布特征和故障的起因,分析了精益制造与数控机床故障维护维修之间的矛盾,提出了在精益生产方式下解决这一矛盾的基本方法.最后,指出精益生产企业探索出一条适合于企业自身、有效的维护维修途径是保证落实精益生产的关键.

  20. Structural Health Monitoring Using Neural Network Based Vibrational System Identification

    CERN Document Server

    Sofge, Donald A

    2007-01-01

    Composite fabrication technologies now provide the means for producing high-strength, low-weight panels, plates, spars and other structural components which use embedded fiber optic sensors and piezoelectric transducers. These materials, often referred to as smart structures, make it possible to sense internal characteristics, such as delaminations or structural degradation. In this effort we use neural network based techniques for modeling and analyzing dynamic structural information for recognizing structural defects. This yields an adaptable system which gives a measure of structural integrity for composite structures.