WorldWideScience

Sample records for ground-engaging drive wheels

  1. PHENOMENON OF CARVED DRIVING WHEELS

    Institute of Scientific and Technical Information of China (English)

    LI Xianghua; ZHANG Jianwu

    2007-01-01

    A newly found phenomenon of carved driving wheels of a rea-wheel-drive tractor used in an airport is discussed. The circum of every driving wheel is damaged at three regions, which distribute regularly and uniformly. Everyday, the tractor tows a trailer which are times heavier than the tractor, and moves on the same road in the airport. The phenomenon is explained by the torsional self-excited vibration system of the powertrain. The simplified torsional vibration system is discribed by a 2-order ordinary differential equation, which has a limit circle. Experiments and numerical simulations show the followings: Because of the heavy trailer, the slip ratio of the tractor's driving wheels is very large. Therefore, there is severe torsional self-excited vibration in the tractor's drivetrain, and the self-excited vibration results in severe and regular fluctuations of the rear wheel's velocity. The severe fluctuations in velocity fastens the damage of the driving wheels. At the same time, the time interval in which an arbitrary point in the circum of the driving wheel contacts with the road twice is two times more than the period of the torsional self-excited vibration, and this times explained the existence of three damaged regions. At last, it points out that the phenomenon can be avoided when the torsional damping is large enough.

  2. Electronic 4-wheel drive control device

    Science.gov (United States)

    Hayato, S.; Takanori, S.; Shigeru, H.; Tatsunori, S.

    1984-01-01

    The internal rotation torque generated during operation of a 4-wheel drive vehicle is reduced using a control device whose clutch is attached to one part of the rear-wheel drive shaft. One torque sensor senses the drive torque associated with the rear wheel drive shaft. A second sensor senses the drive torque associated with the front wheel drive shaft. Revolution count sensors sense the revolutions of each drive shaft. By means of a microcomputer, the engagement of the clutch is changed to insure that the ratio of the torque sensors remains constant.

  3. Omni rotational driving and steering wheel

    DEFF Research Database (Denmark)

    2008-01-01

    Abstract of WO 2008138346  (A1) There is disclosed a driving and steering wheel (112) module (102) with an omni rotational part (106), the module comprising a flange part (104) fixable on a robot, and the omni rotational part (106) comprises an upper omni rotational part (105) and a driving...... and steering wheel part (108), where the omni rotational part (106) is provided for infinite rotation relative to the flange part (104) by both a drive motor (110) and a steering motor (114) being positionable on the flange part (104), and the driving and steering wheel part (108) is suspended from the upper...... omni rotational part (105) with a suspension (116) such that wheel part (108) can move relatively to the upper omni rotational part (105) in a suspension direction (118), and a reduction gear (120) for gearing the drive torque is provided in the wheel part (108) in order e.g. to assure traction...

  4. Mechanical Design Engineering Enabler Project wheel and wheel drives

    Science.gov (United States)

    Nutt, Richard E.; Couch, Britt K.; Holley, John L., Jr.; Garris, Eric S.; Staut, Paul V.

    1992-01-01

    Our group was assigned the responsibility of designing the wheel and wheel drive system for a proof-of-concept model of the lunar-based ENABLER. ENABLER is a multi-purpose, six wheeled vehicle designed to lift and transport heavy objects associated with the construction of a lunar base. The resulting design was based on the performance criteria of the ENABLER. The drive system was designed to enable the vehicle to achieve a speed of 7 mph on a level surface, climb a 30 percent grade, and surpass a one meter high object and one meter wide crevice. The wheel assemblies were designed to support the entire weight of the vehicle on two wheels. The wheels were designed to serve as the main component of the vehicle's suspension and will provide suitable traction for lunar-type surfaces. The expected performance of the drive system for the ENABLER was influenced by many mechanical factors. The expected top speed on a level sandy surface is 4 mph instead of the desired 7 mph. This is due to a lack of necessary power at the wheels. The lack of power resulted from dimension considerations that allowed only an eight horsepower engine and also from mechanical inefficiencies of the hydraulic system. However, the vehicle will be able to climb a 30 percent grade, surpass a one meter high object and one meter wide crevice. The wheel assemblies will be able to support the entire weight of the vehicle on two wheels. The wheels will also provide adequate suspension for the vehicle and sufficient traction for lunar-type surfaces.

  5. Omni rotational driving and steering wheel

    DEFF Research Database (Denmark)

    2008-01-01

    omni rotational part (105) with a suspension (116) such that wheel part (108) can move relatively to the upper omni rotational part (105) in a suspension direction (118), and a reduction gear (120) for gearing the drive torque is provided in the wheel part (108) in order e.g. to assure traction...

  6. General motors front wheel drive 2-mode hybrid transmission

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, James [General Motors Corp., Pontiac, MI (United States). New Transmission Products Group.; Holmes, Alan G. [General Motors Corp., Pontiac, MI (United States). Powertrain Hybrid Architecture

    2009-07-01

    General Motors now expands the application of two-mode hybrid technology to front wheel drive vehicles with the development of a hybrid electric transmission packaged into essentially the same space as a conventional automatic transmission for front wheel drive. This was accomplished using a space-efficient arrangement based on two planetary gear sets and electric motor-generators with large internal diameters. A combination of damper and hydraulically-controlled clutch allow comfortable shutdown and restarting of large-displacement engines in front wheel drive vehicles. The hybrid system delivers electric low-speed urban driving, two continuously variable ranges of transmission speed ratios, four fixed transmission speed ratios, electric acceleration boosting, and regenerative braking. In the first vehicle application, the two-mode hybrid helps to reduce vehicle fuel consumption by approximately one-third. (orig.)

  7. Wheel Torque Distribution of Four-Wheel-Drive Electric Vehicles Based on Multi-Objective Optimization

    Directory of Open Access Journals (Sweden)

    Cheng Lin

    2015-04-01

    Full Text Available The wheel driving torque on four-wheel-drive electric vehicles (4WDEVs can be modulated precisely and continuously, therefore maneuverability and energy-saving control can be carried out at the same time. In this paper, a wheel torque distribution strategy is developed based on multi-objective optimization to improve vehicle maneuverability and reduce energy consumption. In the high-layer of the presented method, sliding mode control is used to calculate the desired yaw moment due to the model inaccuracy and parameter error. In the low-layer, mathematical programming with the penalty function consisting of the yaw moment control offset, the drive system energy loss and the slip ratio constraint is used for wheel torque control allocation. The programming is solved with the combination of off-line and on-line optimization to reduce the calculation cost, and the optimization results are sent to motor controllers as torque commands. Co-simulation based on MATLAB® and Carsim® proves that the developed strategy can both improve the vehicle maneuverability and reduce energy consumption.

  8. Dynamic motion stabilization for front-wheel drive in-wheel motor electric vehicles

    Directory of Open Access Journals (Sweden)

    Jia-Sheng Hu

    2015-12-01

    Full Text Available This article presents a new dynamic motion stabilization approach to front-wheel drive in-wheel motor electric vehicles. The approach includes functions such as traction control system, electronic differential system, and electronic stability control. The presented electric vehicle was endowed with anti-skid performance in longitudinal accelerated start; smooth turning with less tire scrubbing; and safe driving experience in two-dimensional steering. The analysis of the presented system is given in numerical derivations. For practical verifications, this article employed a hands-on electric vehicle named Corsa-electric vehicle to carry out the tests. The presented approach contains an integrated scheme which can achieve the mentioned functions in a single microprocessor. The experimental results demonstrated the effectiveness and feasibility of the presented methodology.

  9. New Record Five-Wheel Drive, Spirit's Sol 1856

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Spirit used its navigation camera to take the images that have been combined into this stereo, 180-degree view of the rover's surroundings during the 1,856th Martian day, or sol, of Spirit's surface mission (March 23, 2009). The center of the view is toward the west-southwest. The rover had driven 25.82 meters (84.7 feet) west-northwestward earlier on Sol 1856. This is the longest drive on Mars so far by a rover using only five wheels. Spirit lost the use of its right-front wheel in March 2006. Before Sol 1856, the farthest Spirit had covered in a single sol's five-wheel drive was 24.83 meters (81.5 feet), on Sol 1363 (Nov. 3, 2007). The Sol 1856 drive made progress on a route planned for taking Spirit around the western side of the low plateau called 'Home Plate.' A portion of the northwestern edge of Home Plate is prominent in the left quarter of this image, toward the south. This view is presented as a cylindrical projection with geometric seam correction.

  10. Torque split between left and right drive shaft over a front wheel drive differential

    OpenAIRE

    Ollé Bernades, Marc

    2011-01-01

    Steering feel and vehicle steering motion is affected by wheel torques from propulsion, especially for front wheel drive cars. Often these problems are referred to as “torque steer”. Many systems interact to cause these problems: propulsion, steering and suspension. Torque steer contributors are not only the differential (friction, self locking effect, Torsen differential), but also the input from the ground and car geometry such as road conditions (friction and surface), the vehicle state...

  11. New Record Five-Wheel Drive, Spirit's Sol 1856 (Stereo)

    Science.gov (United States)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11962 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11962 NASA's Mars Exploration Rover Spirit used its navigation camera to take the images that have been combined into this stereo, 180-degree view of the rover's surroundings during the 1,856th Martian day, or sol, of Spirit's surface mission (March 23, 2009). The center of the view is toward the west-southwest. This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left. The rover had driven 25.82 meters (84.7 feet) west-northwestward earlier on Sol 1856. This is the longest drive on Mars so far by a rover using only five wheels. Spirit lost the use of its right-front wheel in March 2006. Before Sol 1856, the farthest Spirit had covered in a single sol's five-wheel drive was 24.83 meters (81.5 feet), on Sol 1363 (Nov. 3, 2007). The Sol 1856 drive made progress on a route planned for taking Spirit around the western side of the low plateau called 'Home Plate.' A portion of the northwestern edge of Home Plate is prominent in the left quarter of this image, toward the south. This view is presented as a cylindrical-perspective projection with geometric seam correction.

  12. A five-wheel wheelchair with an active-caster drive system.

    Science.gov (United States)

    Munakata, Yu; Tanaka, Aki; Wada, Masayoshi

    2013-06-01

    A novel wheelchair system with an active-caster drive mechanism is presented in this paper. A manual (hand propelled) wheelchair with an external single-wheel drive system forms a five-wheel configuration. The active-caster mechanism is applied to a drive system to motorize a manual wheelchair. Two electric motors which drive a wheel axis and a steering axis of a drive wheel independently are equipped on the active-caster. A coordinated control of the two motors enables the velocity vector on the steering shaft to direct in an arbitrary direction with an arbitrary magnitude. The generated velocity vector allows a wheelchair to go straight and/or rotate completely in a same way as a standard electric wheelchair. Namely 2DOF of the wheelchair can be controlled independently by a single drive wheel without any constraint, such as the orientation of the drive wheel which is well known as a non-holonomic constraint. In addition to the 2DOF mobility, the proposed system enables wheelchair users to change drive modes, a rear drive and a front drive. The drive wheel on the back side of the wheelchair is vertically actuated by a linear motor to change the height of the drive wheel that can vary load distribution and the number of wheels contacting to the ground. The five-wheel-contact makes the wheelchair to move as the normal mode in which the center of rotation is located at the midpoint of the main wheels. Depressing the drive wheel results in lost contacts of the main wheels from the ground in which the center of rotation is jumped at the midpoint of the front wheels, namely it performs as a front drive wheelchair. In this paper, kinematic models of the wheelchair and that with an active-caster drive system are analyzed and a control method by using a 2DOF joystick is derived. Based on the kinematic model, a prototype mechanism of the active-caster is designed and mounted on a manual wheelchair to realize the five-wheel wheelchair. In the experiments, the independent 2

  13. Motion Control of a Four-wheel-drive Omnidirectional Wheelchair with High Step Climbing Capability

    OpenAIRE

    WADA, Masayoshi

    2010-01-01

    Mechanism and omnidirectional control of a 4WD mechanism for wheelchairs are presented in this chapter. The omnidirectional wheelchair system is proposed for improving maneuverability of standard wheelchairs The 4WD mechanism has high mobility which equips four wheels, two omni-wheels in the front and two normal tires in the rear, and all wheels provide traction even with two motors to drive these wheels. To realize holonomic and omnidirectional motion of a chair by utilizing the 4WD mechanis...

  14. APPLIED PROBLEMS OF CURVILINEAR MOTION DYNAMICS OF ALL-WHEEL DRIVE TRACTION MEANS

    Directory of Open Access Journals (Sweden)

    G. S. Gorin

    2014-01-01

    Full Text Available Fundamental principles for hybrid theory on turning of an all-wheel drive system are given in the paper. The paper shows expediency of accounting longitudinal additional tangential reactions (parasitic forces in contacts of central and lateral wheels with foundation. Algorithms for calculating additional tangential reactions have been proposed in the paper. The paper presents calculation kinematics model for turning of steered and rigid bogie with inter-wheel differential at various axial drive.

  15. Position and force control of a vehicle with two or more steerable drive wheels

    Energy Technology Data Exchange (ETDEWEB)

    Reister, D.B.; Unseren, M.A.

    1992-01-01

    When a vehicle with two or more steerable drive wheels is traveling in a circle, the motion of the wheels is constrained. The wheel translational velocity divided by the radius to the center of rotation must be the same for all wheels. When the drive wheels are controlled independently using position control, the motion of the wheels may violate the constraints and the wheels may slip. Consequently, substantial errors can occur in the orientation of the vehicle. A vehicle with N drive wheels has (N - 1) constraints and one degree of freedom. We have developed a new approach to the control of a vehicle with N steerable drive wheels. The novel aspect of our approach is the use of force control. To control the vehicle, we have one degree of freedom for the position on the circle and (N - 1) forces that can be used to reduce errors. Recently, Kankaanranta and Koivo developed a control architecture that allows the force and position degrees of freedom to be decoupled. In the work of Kankaanranta and Koivo the force is an exogenous input We have made the force endogenous by defining the force in terms of the errors in satisfying the rigid body kinematic constraints. We have applied the control architecture to the HERMIES-M robot and have measured a dramatic reduction in error (more than a factor of 20) compared to rations without force control.

  16. Position and force control of a vehicle with two or more steerable drive wheels

    Energy Technology Data Exchange (ETDEWEB)

    Reister, D.B.; Unseren, M.A.

    1992-11-01

    When a vehicle with two or more steerable drive wheels is traveling in a circle, the motion of the wheels is constrained. The wheel translational velocity divided by the radius to the center of rotation must be the same for all wheels. When the drive wheels are controlled independently using position control, the motion of the wheels may violate the constraints and the wheels may slip. Consequently, substantial errors can occur in the orientation of the vehicle. A vehicle with N drive wheels has (N - 1) constraints and one degree of freedom. We have developed a new approach to the control of a vehicle with N steerable drive wheels. The novel aspect of our approach is the use of force control. To control the vehicle, we have one degree of freedom for the position on the circle and (N - 1) forces that can be used to reduce errors. Recently, Kankaanranta and Koivo developed a control architecture that allows the force and position degrees of freedom to be decoupled. In the work of Kankaanranta and Koivo the force is an exogenous input We have made the force endogenous by defining the force in terms of the errors in satisfying the rigid body kinematic constraints. We have applied the control architecture to the HERMIES-M robot and have measured a dramatic reduction in error (more than a factor of 20) compared to rations without force control.

  17. Position and force control of a vehicle with two or more steerable drive wheels

    Energy Technology Data Exchange (ETDEWEB)

    Reister, D.B.; Unseren, M.A.

    1992-10-01

    When a vehicle with two or more steerable drive wheels is traveling in a circle, the motion of the wheels is constrained. The wheel translational velocity divided by the radius to the center of rotation must be the same for all wheels. When the drive wheels are controlled independently using position control, the motion of the wheels may violate the constraints and the wheels may slip. Consequently, substantial errors can occur in the orientation of the vehicle. A vehicle with N drive wheels has (N - 1) constraints and one degree of freedom. We have developed a new approach to the control of a vehicle with N steerable drive wheels. The novel aspect of our approach is the use of force control. To control the vehicle, we have one degree of freedom for the position on the circle and (N - 1) forces that can be used to reduce errors. Recently, Kankaanranta and Koivo developed a control architecture that allows the force and position degrees of freedom to be decoupled. In the work of Kankaanranta and Koivo the force is an exogenous input. We have made the force endogenous by defining the force in terms of the errors in satisfying the rigid body kinematic constraints. We have applied the control architecture to the HERMIES-III robot and have measured a dramatic reduction in error (more than a factor of 20) compared to motions without force control.

  18. A Study of Torque Vectoring and Traction Control for an All-Wheel Drive Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Maharun Mui’nuddin

    2014-07-01

    Full Text Available Common vehicle always experience energy loss during cornering manoeuver. Thus, to ensure it did not happened especially at high speed, a study of torque vectoring and traction control need to be made since it can increase the traction control of tyres during cornering at high speed. The study of torque vectoring and traction control for an all-wheel drive electric vehicle was conducted by modelling an all-wheel drive electric vehicle (EV in ADAMS/Car software. In addition, an optimal control algorithm will be developed for best performance to minimize energy losses using MATLAB/Simulink software. Furthermore, to prove the effectiveness of the all-wheel drive electric, the torque and traction control simulation of the all-wheel drive electric vehicle will be compared with uncontrolled electric vehicle model. According to the result, torque vectoring and traction control of in-wheel motor in all wheel drive EV can help to increase the performance of the electric vehicle during cornering manoeuver. In conclusion, this study of torque vectoring and traction control for an all-wheel drive electric vehicle will help researchers to improve the design of the future electric vehicle in term of the vehicle performance during cornering manoeuvre.

  19. Wheeled Vehicle Drive Lines, Axles, and Suspension Systems. Military Curriculum Materials for Vocational and Technical Education.

    Science.gov (United States)

    Army Ordnance Center and School, Aberdeen Proving Ground, MD.

    This course is one of several subcourses that make up the entire Army correspondence course on wheeled vehicle maintenance. The subcourse is designed to provide the student with information about the operation, malfunction diagnosis, maintenance, and repair of wheeled vehicle drive lines, axles, and suspension systems. It provides the basic…

  20. A rough terrain traction control technique for all-wheel-drive mobile robots

    National Research Council Canada - National Science Library

    Silva, Alexandre F. Barral; Santos, Auderi Vicente; Meggiolaro, Marco Antonio; Speranza Neto, Mauro

    2010-01-01

    ... - and guaranteeing an adequate trajectory and speed control while reducing the power requirements. Traction control of all-wheel-drive robots in rough terrain was originally motivated by space exploration, such as in the case of the Mars Exploration Rovers...

  1. Two wheel speed robust sliding mode control for electric vehicle drive

    Directory of Open Access Journals (Sweden)

    Abdelfatah Nasri

    2008-01-01

    Full Text Available Nowadays the uses of electrical power resources are integrated in the modern vehicle motion traction chain so new technologies allow the development of electric vehicles (EV by means of static converters-related electric motors. All mechanical transmission devices are eliminated and vehicle wheel motion can be controlled by means of power electronics. The proposed propulsing system consists of two induction motors (IM that ensure the drive of the two back driving wheels. The proposed control structure-called independent machines- for speed control permit the achievement of an electronic differential. The electronic differential system ensures the robust control of the vehicle behavior on the road. It also allows controlling independently, every driving wheel to turn at different speeds in any curve. This paper presents the study and the sliding mode control strategy of the electric vehicle driving wheels.

  2. The relationship between four-wheel drives and risky driving behaviours

    Directory of Open Access Journals (Sweden)

    Abdulbari Bener

    2014-07-01

    Full Text Available Background: Given the increased number of four wheel drive (4WD vehicles in Qatar and their involvement in crashes, casualties and road fatalities, it is important to understand the association between risky driving behavior and 4WD crashes. Aim/Objective: This study aimed to determine the association between risky driving behaviours and 4WD vehicles and its impact on road traffic accidents in the State of Qatar. Materials and Methods: A cross sectional survey was conducted using a multistage stratified cluster sampling technique to recruit 1824 drivers of two wheel drive (small cars and 4WD across different primary health centres (PHCs in Qatar. The Driver Behaviour Questionnaire (DBQ and Driver Skill Inventory (DSI were used to collect the data. Information regarding socio-demographic and road traffic crashes during last three years was also obtained. Multivariate logistic regression was used to analyse the data. Results: 762 (41.8% owned 4WD vehicles. Drivers of 4WD were significantly higher between 30-50 years age (P < 0.001, urban dwellers (P = 0.003, having more driving experience (atleast 5 years (P < 0.001 and annual mileage higher than the drivers of small cars (P < 0.001. A significantly higher proportion of 4WD drivers had previous penalties for traffic violations such as crossing a red traffic signal (51.6% vs. 21.4%; P < 0.001 or exceeding the speed limit (35% vs. 27.8%; P < 0.001. A higher proportion of 4WDs' drivers reported previous involvement in accidents as compared to the drivers of small cars (42.4% vs. 35.7%; p 0.004. The risk of accident involvement was 1.21 times higher among drivers of 4WD as compared to the counterparts (OR 1.21; 95%CI; 1.01-1.46. Besides, excessive speed, annual mileage, male gender, traffic violations, lapses, errors and driving skills were significantly associated with crashes. Conclusion: The drivers of 4WD cars are at higher risk of crashes as compared to the drivers of small cars. Also, they have

  3. Influence of Tire Dynamics on Slip Ratio Estimation of Independent Driving Wheel System Influence of Tire Dynamics on Slip Ratio Estimation of Independent Driving Wheel System

    Institute of Scientific and Technical Information of China (English)

    LI Jianqiu; SONG Ziyou; WEI Yintao; OUYANG Minggao

    2014-01-01

    The independent driving wheel system, which is composed of in-wheel permanent magnet synchronous motor(I-PMSM) and tire, is more convenient to estimate the slip ratio because the rotary speed of the rotor can be accurately measured. However, the ring speed of the tire ring doesn’t equal to the rotor speed considering the tire deformation. For this reason, a deformable tire and a detailed I-PMSM are modeled by using Matlab/Simulink. Moreover, the tire/road contact interface(a slippery road) is accurately described by the non-linear relaxation length-based model and the Magic Formula pragmatic model. Based on the relatively accurate model, the error of slip ratio estimated by the rotor rotary speed is analyzed in both time and frequency domains when a quarter car is started by the I-PMSM with a definite target torque input curve. In addition, the natural frequencies(NFs) of the driving wheel system with variable parameters are illustrated to present the relationship between the slip ratio estimation error and the NF. According to this relationship, a low-pass filter, whose cut-off frequency corresponds to the NF, is proposed to eliminate the error in the estimated slip ratio. The analysis, concerning the effect of the driving wheel parameters and road conditions on slip ratio estimation, shows that the peak estimation error can be reduced up to 75% when the LPF is adopted. The robustness and effectiveness of the LPF are therefore validated. This paper builds up the deformable tire model and the detailed I-PMSM models, and analyzes the effect of the driving wheel parameters and road conditions on slip ratio estimation.

  4. INVESTIGATION OF PROCESS PERTAINING TO INTERACTION OF TRACTOR DRIVING WHEELS WITH GROUND SURFACE

    Directory of Open Access Journals (Sweden)

    V. V. Guskov

    2017-01-01

    Full Text Available The paper presents results of investigations on the process pertaining to interaction of a driving wheel with ground surface and describes methodology for optimization of backbone parameters. The mentioned process has some specific differences in comparison with the process of wheel rolling along hard surface. Ground surface is represented by mixture of sandy and clay particles with plant residues and it has a number of physical and mechanical properties. The main of these properties is resistance of soil against compression and displacement. Compression process determines a track depth and resistance to motion and displacement process determines wheel gripping property and its tangential traction force. While executing the investigations laws of compression and displacement proposed by Prof.V. V. Katsygin as the most adequate reflection of actual processes have been used in the paper. Motion of the driving wheel along ground surface is accompanied by its slipping. It has been determined that the maximum wheel traction force is formed not with 100% slipping as it was supposed until present but the value has been obtained at 45–60 % slipping according to soil category. The developed integral equations with due account of the aspect make it possible to calculate road hold characteristics of driving wheels of the designed wheel tractor and evaluate its traction, speed and economic characteristics. Methodology has been developed for optimization of backbone parameters of wheeled running gear in the designed tractor such as design mass and adhesion weight, width, diameter and air pressure in a tire. The proposed methodology has been introduced in designing practice of wheeled tractors at OJSC “Minsk Tractor Works”.

  5. EFFECT OF DRIVING WHEEL TYPE ON DRAWBAR PULL OF TRACTOR

    Directory of Open Access Journals (Sweden)

    Rudolf Abrahám

    2013-12-01

    Full Text Available This paper is focused on the possibility of increasing the drawbar pull of agricultural tractor on the soil and grass-covered surface. From our perspective, we have chosen one available and the cheapest way, i.e. steel boots for tyres of small tractors, and this was compared with a newly developed system of auto-extensible blades next to the wheel. The tractor with steel boots and auto-extensible blades reached a higher drawbar pull on average by 70 % in comparison with tyres.

  6. In-line drivetrain and four wheel drive work machine using same

    Science.gov (United States)

    Hoff, Brian

    2008-08-05

    A four wheel drive articulated mine loader is powered by a fuel cell and propelled by a single electric motor. The drivetrain has the first axle, second axle, and motor arranged in series on the work machine chassis. Torque is carried from the electric motor to the back differential via a pinion meshed with the ring gear of the back differential. A second pinion oriented in an opposite direction away from the ring gear is coupled to a drive shaft to transfer torque from the ring gear to the differential of the front axle. Thus, the ring gear of the back differential acts both to receive torque from the motor and to transfer torque to the forward axle. The in-line drive configuration includes a single electric motor and a single reduction gear to power the four wheel drive mine loader.

  7. Influence of tire dynamics on slip ratio estimation of independent driving wheel system

    Science.gov (United States)

    Li, Jianqiu; Song, Ziyou; Wei, Yintao; Ouyang, Minggao

    2014-11-01

    The independent driving wheel system, which is composed of in-wheel permanent magnet synchronous motor(I-PMSM) and tire, is more convenient to estimate the slip ratio because the rotary speed of the rotor can be accurately measured. However, the ring speed of the tire ring doesn't equal to the rotor speed considering the tire deformation. For this reason, a deformable tire and a detailed I-PMSM are modeled by using Matlab/Simulink. Moreover, the tire/road contact interface(a slippery road) is accurately described by the non-linear relaxation length-based model and the Magic Formula pragmatic model. Based on the relatively accurate model, the error of slip ratio estimated by the rotor rotary speed is analyzed in both time and frequency domains when a quarter car is started by the I-PMSM with a definite target torque input curve. In addition, the natural frequencies(NFs) of the driving wheel system with variable parameters are illustrated to present the relationship between the slip ratio estimation error and the NF. According to this relationship, a low-pass filter, whose cut-off frequency corresponds to the NF, is proposed to eliminate the error in the estimated slip ratio. The analysis, concerning the effect of the driving wheel parameters and road conditions on slip ratio estimation, shows that the peak estimation error can be reduced up to 75% when the LPF is adopted. The robustness and effectiveness of the LPF are therefore validated. This paper builds up the deformable tire model and the detailed I-PMSM models, and analyzes the effect of the driving wheel parameters and road conditions on slip ratio estimation.

  8. Modeling and Simulation of the Vibration Characteristics of the In-Wheel Motor Driving Vehicle Based on Bond Graph

    Directory of Open Access Journals (Sweden)

    Di Tan

    2016-01-01

    Full Text Available Bond graph theory is applied to the modeling and analysis of the vibration characteristics of the in-wheel motor driving vehicle. First, an 11-degree-of-freedom vibration model of the in-wheel motor driving vehicle is established based on bond graph, and then the correctness of the model is verified. Second, under the driving condition of class B road excitations and a speed of 50 Km/h, the vibration characteristics of the in-wheel motor driving vehicle are simulated and analyzed, and the activity of each part in the system is then calculated. Third, these parts that have less of an effect on the vibration characteristics of an in-wheel motor driving vehicle are identified according to the magnitude of the activity, and then the model is simplified by removing these parts. Finally, the reliability of the simplified model is verified by comparing the vibration characteristics of the model before and after simplification. This study can provide a method for the modeling and simulation of the vibration characteristics of the in-wheel motor driving vehicle.

  9. Driving Control Research for Longitudinal Dynamics of Electric Vehicles with Independently Driven Front and Rear Wheels

    Directory of Open Access Journals (Sweden)

    Wei Liu

    2013-01-01

    Full Text Available This paper takes the electric off-road vehicle with separated driven axles as the research object. To solve the longitudinal dynamics driving control problems, vehicle dynamics model, and control strategies were studied and the corresponding simulation was carried out. An 8-DOF vehicle dynamics model with separated driven axles was built. The driving control strategies on the typical roads were put forward. The recognition algorithm of the typical road surfaces based on the wheels’ slip rates was proposed. And the two control systems were designed including the pedal opening degree adjustment control system based on PI algorithm and the interaxle torque distribution control system based on sliding mode control algorithm. The driving control flow of the proposed vehicle combining the pedal adjustment control system with the interaxle torque distribution control system was developed. And the driven control strategies for the typical roads were simulated. Simulation results show that the proposed drive control strategies can adapt to different typical road surfaces, limit the slip rates of the driving wheels within the stable zone, and ensure the vehicle driving safely and stably in accordance with the driver's intention.

  10. Automatic Adaptive Control of Full-Flow Hydrostatic Transmission for Tri-axial All-Wheel Drive Vehicle

    Directory of Open Access Journals (Sweden)

    A. V. Lepeshkin

    2015-01-01

    Full Text Available The article presents the research results aimed at theoretical justification of requirements for automatic adaptive control systems (AACS to be the basis of developed intelligent transmissions of multi-drive wheeled all-terrain vehicles.To conduct studies was used a specially developed mathematical model of motion of triaxial all-wheel drive vehicle “Gidrohod-49061”, equipped with CVT full flow hydrostatic transmission (HST on a non-deformable support surface. This mathematical model is to simulate different operating conditions of the vehicle, which are a consequence both of disturbances from the road and of control actions from the driver and AACS.The article presents some results of theoretical and experimental studies to prove the adequacy of the developed mathematical model.The results analysis of mathematical modeling proved conclusively that one of the main tasks to be solved owing to developed AACS of intelligent transmission of multi-drive wheeled vehicle is to reduce the mismatch value in operation of drive wheels.It is shown that the reasons for these mismatches can be either AACS error when processing control signals or other factors that characterize operating conditions of the drive wheels. Therefore, the paper proposes to develop a tracking control system of HST of the considered vehicle using the output parameters characterizing operation conditions of its drive wheels rather than the values of control parameters of hydraulic working volumes. As output parameters, it is proposed to use the speed of the drive wheels (hydro-motor shafts and pressure drop in the main pump hydraulic drives, coming to HST.Therefore it is proposed to develop HST AACS of the vehicle under consideration, as a system of two-level regulation, including the kinematic (main level and power (level of correction circuits. The former provides, at the first approximation, the required values of the drive wheel speeds in the given conditions, and the latter

  11. Referential coding of steering-wheel button presses in a simulated driving cockpit.

    Science.gov (United States)

    Xiong, Aiping; Proctor, Robert W

    2015-12-01

    The present study investigated whether left and right pushbuttons on a steering wheel are coded relative to an "infotainment display" in a simulated driving cockpit. Participants performed a go/no-go Simon task in which they responded on trials for which a tone, presented from a left or right speaker, was 1 of 2 pitches (low or high) with a single button press (left in 1 trial block; right in another). Without the infotainment display in Experiment 1, both left and right responses showed Simon effects of similar size. In both Experiments 2 and 3, the infotainment display was located to the right or left, and the Simon effect was smaller for the response that was on the side of the infotainment display than for the response that was on the opposite side. The results indicate that in a driving cockpit environment, the pushbutton responses are coded as left and right with respect not only to the wheel-based frame but also to a salient object like the infotainment display. The general point for application is that the driver's spatial representation of responses, and consequently performance, can be influenced by multiple frames of reference.

  12. Integrated Fault Diagnosis Algorithm for Motor Sensors of In-Wheel Independent Drive Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Namju Jeon

    2016-12-01

    Full Text Available An integrated fault-diagnosis algorithm for a motor sensor of in-wheel independent drive electric vehicles is presented. This paper proposes a method that integrates the high- and low-level fault diagnoses to improve the robustness and performance of the system. For the high-level fault diagnosis of vehicle dynamics, a planar two-track non-linear model is first selected, and the longitudinal and lateral forces are calculated. To ensure redundancy of the system, correlation between the sensor and residual in the vehicle dynamics is analyzed to detect and separate the fault of the drive motor system of each wheel. To diagnose the motor system for low-level faults, the state equation of an interior permanent magnet synchronous motor is developed, and a parity equation is used to diagnose the fault of the electric current and position sensors. The validity of the high-level fault-diagnosis algorithm is verified using Carsim and Matlab/Simulink co-simulation. The low-level fault diagnosis is verified through Matlab/Simulink simulation and experiments. Finally, according to the residuals of the high- and low-level fault diagnoses, fault-detection flags are defined. On the basis of this information, an integrated fault-diagnosis strategy is proposed.

  13. Integrated Fault Diagnosis Algorithm for Motor Sensors of In-Wheel Independent Drive Electric Vehicles.

    Science.gov (United States)

    Jeon, Namju; Lee, Hyeongcheol

    2016-12-12

    An integrated fault-diagnosis algorithm for a motor sensor of in-wheel independent drive electric vehicles is presented. This paper proposes a method that integrates the high- and low-level fault diagnoses to improve the robustness and performance of the system. For the high-level fault diagnosis of vehicle dynamics, a planar two-track non-linear model is first selected, and the longitudinal and lateral forces are calculated. To ensure redundancy of the system, correlation between the sensor and residual in the vehicle dynamics is analyzed to detect and separate the fault of the drive motor system of each wheel. To diagnose the motor system for low-level faults, the state equation of an interior permanent magnet synchronous motor is developed, and a parity equation is used to diagnose the fault of the electric current and position sensors. The validity of the high-level fault-diagnosis algorithm is verified using Carsim and Matlab/Simulink co-simulation. The low-level fault diagnosis is verified through Matlab/Simulink simulation and experiments. Finally, according to the residuals of the high- and low-level fault diagnoses, fault-detection flags are defined. On the basis of this information, an integrated fault-diagnosis strategy is proposed.

  14. Electric Drive for an In-wheel Fractional-slot Axial Flux Machine

    Institute of Scientific and Technical Information of China (English)

    Luigi Alberti; Nicola Bian-chi

    2008-01-01

    This paper describes the electric drive for an in-wheel fractional-slot axial flux machine, designed for achievinga wide flux-weakening operating region.By using a slotted stator with fractional-slot windings and additional coresenclosing end windings,the axial flux machine reaches a wide constant power speed range. The machine is designed forincreasing flux-weakening capability while obtaining low harmonic back-electromotive force and low cogging torque.A 10maximize the output torque in the flux-weakening region, is designed and implemented.The goodness of both design andcontrol algorithm is proved by experimental tests.However,such a fractional-slot machine has not only advantages.Rotorlosses are very high ,and they have to be properly considered during the design process.

  15. Design Study for Controllable Electric Motor for Three Wheel Drive, In Wheel Mounting on Professional, Electric, Lawn Mower

    DEFF Research Database (Denmark)

    Lu, Kaiyuan

    Design of a new generation of electric drive motor for professional lawnmowers forms the basic objective of this thesis. Modern drive concepts produces a growing demand for electrical machines featuring high torque density, and suitable for direct drive applications. Much attention is presently...

  16. An Acceleration Slip Regulation Strategy for Four-Wheel Drive Electric Vehicles Based on Sliding Mode Control

    Directory of Open Access Journals (Sweden)

    Hongwen He

    2014-06-01

    Full Text Available This paper presents an acceleration slip regulation (ASR system for four-wheel drive (4WD electric vehicles, which are driven by the front and rear axles simultaneously. The ASR control strategy includes three control modes: average distribution of inter-axle torque, optimal distribution of inter-axle torque and independent control of optimal slip rate, respectively, which are designed based on the torque adaptive principle of inter-axle differential and sliding mode control theory. Furthermore, in order to accurately describe the longitudinal tyre force characteristic, a slip rate calculation formula in the form of a state equation was used for solving the numerical problem posed by the traditional way. A simulation was carried out with the MATLAB/Simulink software. The simulation results show that the proposed ASR system can fully use the road friction condition, inhibit the drive-wheels from slipping, and improve the vehicle longitudinal driving stability.

  17. Balanced Motions Realization for a Mechanical Regulators Free and Front-Wheel Drive Bicycle Robot Under Zero Forward Speed

    Directory of Open Access Journals (Sweden)

    Yonghua Huang

    2013-08-01

    Full Text Available This paper focuses on a mechanical regulator free and front- wheel drive bicycle robot. We present a scheme to achieve the robot's track-stand motion and circular motion under zero forward speed. In a situation where the robot's front-bar is locked at 90 degrees, a kinetic constraint about the rotating rate of the front-wheel and the yawing rate of the frame is derived. Using the constraint as a basis, we developed a simplified model of two independent velocities for the robot. The model suggests there is an under-actuated rolling angle in the system. Our control strategy originates from the under- actuated characteristics of the robot system. Concretely, we linearize the rolling angle of the frame and set the bicycle robot to regulate its tilting by rotating the front-wheel. In the track-stand motion, we control the position and the rotational rate of the front-wheel; but in the circular motion, only the rotational rate of the front-wheel is strictly regulated. Both simulations and physical experiments results show that our strategy is effective for achieving these two motions.

  18. Design Study for Controllable Electric Motor for Three Wheel Drive, In Wheel Mounting on Professional, Electric, Lawn Mower

    DEFF Research Database (Denmark)

    Lu, Kaiyuan

    .g. reduction of the output torque and changes of inductance, which will cause non-linearity in the machine. Saturation effects may not be neglected if accurate results are required. A substantial part of this thesis is devoted to modelling and performance analysis of PMTFM. Design improvement of PMTFM......Design of a new generation of electric drive motor for professional lawnmowers forms the basic objective of this thesis. Modern drive concepts produces a growing demand for electrical machines featuring high torque density, and suitable for direct drive applications. Much attention is presently...

  19. Handling performance control for hybrid 8-wheel-drive vehicle and simulation verification

    Science.gov (United States)

    Ni, Jun; Hu, Jibin

    2016-08-01

    In order to improve handling performance of a hybrid 8-Wheel-Drive vehicle, the handling performance control strategy was proposed. For armoured vehicle, besides handling stability in high speed, the minimum steer radius in low speed is also a key tactical and technical index. Based on that, the proposed handling performance control strategy includes 'Handling Stability' and 'Radius Minimization' control modes. In 'Handling Stability' control mode, 'Neutralsteer Radio' is defined to adjust the steering characteristics to satisfy different demand in different speed range. In 'Radius Minimization' control mode, the independent motors are controlled to provide an additional yaw moment to decrease the minimum steer radius. In order to verify the strategy, a simulation platform was built including engine and continuously variable transmission systems, generator and battery systems, independent motors and controllers systems, vehicle dynamic and tyre mechanical systems. The simulation results show that the handling performance of the vehicle can be enhanced significantly, and the minimum steer radius can be decreased by 20% which is significant improvement compared to the common level of main battle armoured vehicle around the world.

  20. Design and analysis of new fault-tolerant permanent magnet motors for four-wheel-driving electric vehicles

    Science.gov (United States)

    Liu, Guohai; Gong, Wensheng; Chen, Qian; Jian, Linni; Shen, Yue; Zhao, Wenxiang

    2012-04-01

    In this paper, a novel in-wheel permanent-magnet (PM) motor for four-wheel-driving electrical vehicles is proposed. It adopts an outer-rotor topology, which can help generate a large drive torque, in order to achieve prominent dynamic performance of the vehicle. Moreover, by adopting single-layer concentrated-windings, fault-tolerant teeth, and the optimal combination of slot and pole numbers, the proposed motor inherently offers negligible electromagnetic coupling between different phase windings, hence, it possesses a fault-tolerant characteristic. Meanwhile, the phase back electromotive force waveforms can be designed to be sinusoidal by employing PMs with a trapezoidal shape, eccentric armature teeth, and unequal tooth widths. The electromagnetic performance is comprehensively investigated and the optimal design is conducted by using the finite-element method.

  1. Theoretical investigation on the dynamic behaviour of bucket wheel drives; Theoretische Untersuchungen des dynamischen Verhaltens von Schaufelradantrieben

    Energy Technology Data Exchange (ETDEWEB)

    Schlecht, B. [Krupp Foerdertechnik GmbH, Luebeck (Germany); Wuensch, D.; Christanhemmers, A. [Duisburg Univ. (Germany). Fachgebiet Konstruktionslehre und Foerdertechnik

    1999-01-01

    In the course of the continuous further development of a series of standardized bucket wheel excavators a bucket wheel drive was designed which is distinguished by a particularly high performance rating. In order to determine the dynamic stresses to be expected a simulation model for analysis of the torsional vibrations was set up. This model comprises 15 rotary bodies and, in addition to two planetary gear systems, includes a stepped bevel gear, a cardan shaft and a hydrodynamic starting coupling. The drive is effected by means of an induction machine. The simulation results show that the drive phases are effectively correlated dynamically. Unfavourable operating conditions, such as `impacts` and `blocking of bucket wheel` neither lead to undesirable excitation of resonance frequencies, nor do they cause unexpectedly high additional dynamic stresses. (orig.) [Deutsch] Im Zuge der kontinuierlichen Weiterentwicklung einer Baureihe von standardisierten Schaufelradbaggern wurde ein Schaufelradantrieb entwickelt, der sich durch eine besonders hohe Leistungsdichte auszeichnet. Zur Ermittlung der zu erwartenden dynamischen Beanspruchungen wurde ein Simulationsmodell zur Torsionsschwingungsanalyse erstellt. Das Modell umfasst 15 Drehmassen und beinhaltet neben zwei Planetengetrieben eine Kegelradstufe, eine Gelenkwelle und eine hydrodynamische Anlaufkupplung. Der Antrieb erfolgt ueber eine Asynchronmaschine. Die Ergebnisse der Simulation belegen, dass der Antriebsstrang dynamisch gut abgestimmt ist. Die unguenstigen Betriebszustaende Stoesse sowie Blockieren des Schaufelrades fuehren weder zur unerwuenschten Anregung von Resonanzfrequenzen noch bedingen sie unerwartet hohe dynamische Zusatzbeanspruchungen. (orig.)

  2. Mobility potential of a robotic six-wheeled omnidirectional drive vehicle (ODV) with z-axis and tire inflation control

    Science.gov (United States)

    Witus, Gary

    2000-07-01

    Robot vehicle mobility is the product of the physical configuration, mechatronics (sensors, actuators, and control) and the motion programs for different obstacles, terrain conditions, and maneuver objectives. This paper examines the mobility potential of a robotic 6-by-6 wheeled omni-directional drive vehicle (ODV) with z-axis and tire inflation control. Ad ODV can steer and drive all wheels independently. The direction of motion is independent of the orientation of the body. Z- axis control refers to independent control of the suspension elevation at each wheel. Pneumatic tire inflation control provides the ability to inflate and deflate individual tires. The paper describes motion programs for various discrete obstacles and challenging terrain conditions. The paper illustrates how ODV control, z-axis control and tire inflation control interact to provide high mobility with respect to cornering, maneuvering on slopes, negotiating vertical step and horizontal gap obstacles, and braking/acceleration on soft soil and slick surfaces. The paper derives guidelines for the physical dimensions of the vehicle needed to achieve these capabilities.

  3. Implications of driving patterns on well-to-wheel performance of plug-in hybrid electric vehicles.

    Science.gov (United States)

    Raykin, Leon; MacLean, Heather L; Roorda, Matthew J

    2012-06-05

    This study examines how driving patterns (distance and conditions) and the electricity generation supply interact to impact well-to-wheel (WTW) energy use and greenhouse gas (GHG) emissions of plug-in hybrid electric vehicles (PHEVs). The WTW performance of a PHEV is compared with that of a similar (nonplug-in) gasoline hybrid electric vehicle and internal combustion engine vehicle (ICEV). Driving PHEVs for short distances between recharging generally results in lower WTW total and fossil energy use and GHG emissions per kilometer compared to driving long distances, but the extent of the reductions depends on the electricity supply. For example, the shortest driving pattern in this study with hydroelectricity uses 81% less fossil energy than the longest driving pattern. However, the shortest driving pattern with coal-based electricity uses only 28% less fossil energy. Similar trends are observed in reductions relative to the nonplug-in vehicles. Irrespective of the electricity supply, PHEVs result in greater reductions in WTW energy use and GHG emissions relative to ICEVs for city than highway driving conditions. PHEVs charging from coal facilities only reduce WTW energy use and GHG emissions relative to ICEVs for certain favorable driving conditions. The study results have implications for environmentally beneficial PHEV adoption and usage patterns.

  4. Mathematical description of the position of mining chain links on a driving chain wheel

    Energy Technology Data Exchange (ETDEWEB)

    Dolipski, M.

    1982-01-01

    The paper analyzes effects of geometry on interaction between the chain and chain wheels of face conveyors in underground coal mines. Interaction between chain links and wheel toothing is investigated using mathematical models. Three mesh types are comparatively evaluated, so-called normal mesh, nominal mesh and special mesh. Chain position on the chain wheel is shown in 3 schemes. Mathematical formulae used for characterizing mesh types are derived. Effects of the following factors on interaction between a chain link and a chain wheel are analyzed: link quality and differences in quality and dimensions among chain links, friction wear of links and toothing, elastic and plastic chain elongation, friction between links and toothing. A geometric model of the interaction between the chain wheel and haulage chain (in the form of a double polygon) is used. The mathematical model permits the following problems to be analyzed: load distribution among chain links on a chain wheel, load distribution on toothing, load fluctuations, effects of friction wear of chain and toothing. Examples of practical use of the formulae are discussed. (14 refs.)

  5. Investigating the effect of tractive parameters on imposed vertical stresses under driving wheel using a soil bin test rig facility

    Directory of Open Access Journals (Sweden)

    H Taghavifar

    2015-09-01

    Full Text Available Introduction: Tire tractive parameters of the driving wheel are of the most substantial factors for the evaluation of the performance of agricultural tractors. Great tractive efficiency has called the attention of vehicle designers to attain economic efficiency owing to the minimization of fuel consumption. At terrain-tire interface, some soil physical-mechanical changes occur that lead to unwanted soil compaction. Of the influential parameters for the creation of soil compaction is the soil stresses formed owing to the wheeled vehicle trafficking. While the increase of tractive efficiency is desired, minimization of soil stresses should also be considered with the same importance to make a trade-off between the aforementioned parameters. There are numerous studies documented in the literature that deal with the measurement of soil stress/strain data due to the wheeled vehicle trafficking and also those works that address the correlation between the soil stress and soil compaction. It is recognized that in order to reduce soil compaction both at topsoil and subsoil levels, the soil stress at the soil-tire interface should be reduced. There are various parameters that affect the tractive efficiency and the soil stress creation such as wheel load, slip, tire inflation pressure, velocity, etc. On the other hand, the wheel is subjected to the torques and forces exerted to the vehicle and the vehicle dynamics are significantly affected by the soil-wheel interactions. Survey of the literature shows that numerous studies have focused on the evaluation of tractive efficiency both in field test and controlled conditions in laboratories with the intention of increasing tractive efficiency. The studies dedicated to the soil mechanical strength are more engaged with the approaches to minimize the soil stress propagation. The present study considers both factors and considers the most influential tire parameters such as wheel, velocity and slip to assess the

  6. Energy analysis of electric vehicles using batteries or fuel cells through well-to-wheel driving cycle simulations

    Energy Technology Data Exchange (ETDEWEB)

    Campanari, Stefano; Manzolini, Giampaolo; Garcia de la Iglesia, Fernando [Politecnico di Milano, Department of Energy, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

    2009-01-15

    This work presents a study of the energy and environmental balances for electric vehicles using batteries or fuel cells, through the methodology of the well to wheel (WTW) analysis, applied to ECE-EUDC driving cycle simulations. Well to wheel balances are carried out considering different scenarios for the primary energy supply. The fuel cell electric vehicles (FCEV) are based on the polymer electrolyte membrane (PEM) technology, and it is discussed the possibility to feed the fuel cell with (i) hydrogen directly stored onboard and generated separately by water hydrolysis (using renewable energy sources) or by conversion processes using coal or natural gas as primary energy source (through gasification or reforming), (ii) hydrogen generated onboard with a fuel processor fed by natural gas, ethanol, methanol or gasoline. The battery electric vehicles (BEV) are based on Li-ion batteries charged with electricity generated by central power stations, either based on renewable energy, coal, natural gas or reflecting the average EU power generation feedstock. A further alternative is considered: the integration of a small battery to FCEV, exploiting a hybrid solution that allows recovering energy during decelerations and substantially improves the system energy efficiency. After a preliminary WTW analysis carried out under nominal operating conditions, the work discusses the simulation of the vehicles energy consumption when following standardized ECE-EUDC driving cycle. The analysis is carried out considering different hypothesis about the vehicle driving range, the maximum speed requirements and the possibility to sustain more aggressive driving cycles. The analysis shows interesting conclusions, with best results achieved by BEVs only for very limited driving range requirements, while the fuel cell solutions yield best performances for more extended driving ranges where the battery weight becomes too high. Results are finally compared to those of conventional internal

  7. A Study on the Control Performance of Electronic Differential System for Four-Wheel Drive Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Dejun Yin

    2017-01-01

    Full Text Available The electronic differential system (EDS is an important issue for four-wheel drive electric vehicles. This paper delineates an advanced EDS steering strategy and carries out a careful study of its control performance by numerical simulations that comply with the requirements of ISO4238:2012. The results demonstrate that the EDS feedback gain plays an important role to its control performance, particularly to its steering characteristics. Moreover, the analysis and discussion disclose the mechanism of the relationship between the feedback gain and the steering characteristics, which will contribute to further research and EDS development.

  8. Vehicle Velocity and Roll Angle Estimation with Road and Friction Adaptation for Four-Wheel Independent Drive Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Linhui Zhao

    2014-01-01

    Full Text Available Vehicle velocity and roll angle are important information for active safety control systems of four-wheel independent drive electric vehicle. In order to obtain robustness estimation of vehicle velocity and roll angle, a novel method is proposed based on vehicle dynamics and the measurement information provided by the sensors equipped in modern cars. The method is robust with respect to different road and friction conditions. Firstly, the dynamic characteristics of four-wheel independent drive electric vehicle are analyzed, and a four-degree-of-freedom nonlinear dynamic model of vehicle and a tire longitudinal dynamic equation are established. The relationship between the longitudinal and lateral friction forces is derived based on Dugoff tire model. The unknown input reconstruction technique of sliding mode observer is used to achieve longitudinal tire friction force estimation. A simple observer is designed for the estimation of the roll angle of the vehicle. And then using the relationship, the estimated longitudinal friction forces and roll angle, a sliding mode observer for vehicle velocity estimation is provided, which does not need to know the tire-road friction coefficient and road angles. Finally, the proposed method is evaluated experimentally under a variety of maneuvers and road conditions.

  9. A Methodology for Selection of Optimum Power Rating of Propulsion Motor of Three Wheeled Electric Vehicle on Indian Drive Cycle (IDC

    Directory of Open Access Journals (Sweden)

    Prasun Mishra

    2013-06-01

    Full Text Available Optimum power rating of propulsion motor is an important issue for designing efficient drive train for a three wheeled battery operated electric vehicle application on standard drive cycle like Indian Drive Cycle of Indian urban and suburban areas. This paper deals with proper estimation of power rating of electric motor by root means square technique while considering the limitations of overloading and under loading operation of motor used in electric vehicle along with some specified design parameters, aiming towards better performance than that of a conventional IC engine driven vehicle. Dynamics of three wheeled vehicle is simulated on MATLAB/Simulink environment under a sequence of road grade angle variation in Indian Drive cycle (IDC, which is formulated by Automotive Research Association of India, Pune. Using simulated vehicle dynamics, power rating of the motor is estimated so that it can be operated efficiently and safely throughout the entire Indian drive Cycle.

  10. DC Brushless Motor Control Design and Preliminary Testing for Independent 4-Wheel Drive Rev-11 Robotic Platform

    Directory of Open Access Journals (Sweden)

    Roni Permana Saputra

    2012-03-01

    Full Text Available This paper discusses the design of control system for brushless DC motor using microcontroller ATMega 16 that will be applied to an independent 4-wheel drive Mobile Robot LIPI version 2 (REV-11. The control system consists of two parts which are brushless DC motor control module and supervisory control module that coordinates the desired command to the motor control module. To control the REV-11 platform, supervisory control transmit the reference data of speed and direction of motor to control the speed and direction of each actuator on the platform REV-11. From the test results it is concluded that the designed control system work properly to coordinate and control the speed and direction of motion of the actuator motor REV-11 platform. 

  11. FOUR WHEELS DRIVEN INDEPENDENTLY BY ONE PUMP DRIVING FOUR HYDRAULIC MOTORS

    Institute of Scientific and Technical Information of China (English)

    Wu Baolin; Qiu Lihua; Wang Zhanlin

    2005-01-01

    An improved Narendra model reference adaptive control (MRAC) scheme is proposed to research one variable displacement pump driving four hydraulic variable displacement motors. This approach not only ensures the underdamped and unstable system be global uniform asymptotic stability, but also has good robustness in these aspects of modeling uncertainty, pressure fluctuation of constant pressure network, and disturbance from external load, which also upgrades the rapidity of system response so as to make controlled system with nicer dynamic quality. The scheme of one pump driving four motors can meet the demand on off-road mobility of engineering vehicles and armored cars. A proof of stability about improved Narendra MRAC scheme is also given.

  12. Two-wheel drive-based DNA nanomachine and its sensing potential for highly sensitive analysis of cancer-related gene.

    Science.gov (United States)

    Xu, Jianguo; Wu, Zai-Sheng; Wang, Zhenmeng; Li, Hongling; Le, Jingqing; Jia, Lee

    2016-09-01

    With the biological significance and important advances of nano-scale DNA devices, scientific activities have been directed toward developing molecular machinery. In this work, we present a novel two-wheel drive-based DNA nanomachine composed of one signaling recognition probe (SRP), one label-free recognition probe (LRP), and one driving primer (DP). Target DNA hybridization can activate LRP-based wheel driving by resorting to DP-mediated polymerization/nicking/displacement cycles. This in turn results in the accumulation of nicked strand 1 (NS1) that can initiate extended SRP-based wheel driving. As a result, the hairpin structure of SRP is stretched and pre-quenched fluorescence is restored. Meanwhile, lots of nicked strand 2 (NS2) are produced, which could hybridize perfectly with SRP and lead to further fluorescence amplification. It is worth noting that, because the nanomachine operation relies strongly on inputted target trigger, the unwanted background is completely eliminated. The detection limit of 1 pM and an excellent capability to recognize the single-base mutation were achieved. Significantly, the interrogating of target trigger extracted from cancer cells is already available, reflecting the potential for practical applications. As a proof-of-concept building, the unique analytical properties would significantly benefit the DNA nanomachines and reveal great promise in biochemical and biomedical studies.

  13. Driving a more effective health care market by putting consumers behind the wheel.

    Science.gov (United States)

    Beauregard, T R

    2001-01-01

    In any other rational market, the consumer drives demand, and the provider responds with products and services aimed at meeting individual needs. This rational market does not exist in today's group health care system. The ramifications are significant: declining consumer and provider satisfaction, out-of-control costs, a rising uninsured population, and growing employer burdens. Turning this chaotic world around requires a more active and informed consumer. Transformation is under way with solutions like Sageo, a new e-business from Hewitt Associates that is revolutionizing the way health care benefits are offered, selected, and administered. For companies that offer Sageo's services, their employees and retirees gain direct access to health care coverage and content, enabling them to research, select, and enroll in the appropriate package based on their individual needs.

  14. A Novel Mittag-Leffler Kernel Based Hybrid Fault Diagnosis Method for Wheeled Robot Driving System

    Directory of Open Access Journals (Sweden)

    Xianfeng Yuan

    2015-01-01

    presents a novel hybrid fault diagnosis framework based on Mittag-Leffler kernel (ML-kernel support vector machine (SVM and Dempster-Shafer (D-S fusion. Using sensor data sampled under different running conditions, the proposed approach initially establishes multiple principal component analysis (PCA models for fault feature extraction. The fault feature vectors are then applied to train the probabilistic SVM (PSVM classifiers that arrive at a preliminary fault diagnosis. To improve the accuracy of preliminary results, a novel ML-kernel based PSVM classifier is proposed in this paper, and the positive definiteness of the ML-kernel is proved as well. The basic probability assignments (BPAs are defined based on the preliminary fault diagnosis results and their confidence values. Eventually, the final fault diagnosis result is archived by the fusion of the BPAs. Experimental results show that the proposed framework not only is capable of detecting and identifying the faults in the robot driving system, but also has better performance in stability and diagnosis accuracy compared with the traditional methods.

  15. Validation of the finite element simulation to estimate the rolling resistance of a non-driving wheel with experimental tests

    Directory of Open Access Journals (Sweden)

    N Dibagar

    2015-09-01

    rubber materials for the tire. Tire model consisted of three components: tread, rubber and ring. Using a soil bin and one wheel tester with their related equipment, experimental tests were carried out in the workstation of mechanics of bio system engineering department of the Urmia University. This system includes various sections such as soil storage in dimensions of 22×2×1 meter, tools carrier or tracker, soil processing equipment, dynamic system, evaluation tools and controlling systems. In order to launch the collection and supply required power for wheel carrier, an industrial three phase electromotor with 22 kW (30 hp was used. Both numerical and experimental tests were done at three levels of wheel dynamic load (1, 2, 3, 4 and 5 kN, tire inflation pressure (100, 200 and 300 kPa and four levels of speed (0.25, 0.45, 0.65, 0.9 and 1.15 m s-1 to obtain the rolling resistance of the tire. Results and discussion: In order to evaluate the performance of final non driving tire-soil model to estimate the rolling resistance, numerical results were compared with preliminary experimental data obtained from the soil-bin tests. The comparison showed reasonably good agreement between the computed and measured general pattern of the rolling resistance at the tire-soil interface under different speeds, vertical loads and inflation pressures. In both tests, a specified relation was not seen between tire velocity and its rolling resistance, as it was not seen in empirical models such as Wismar and Luce. Correlation coefficient between experimental and numerical data, in the minimum and maximum value of tire inflation pressure was computed to be 0.06 and 0.016 percent, respectively. The amount of tire rolling resistance significantly increased with increase of tire vertical load. Correlation coefficient between experimental and numerical data, in the minimum and maximum vertical loads was computed to be 80 and 87 percent, respectively. Gent and Walter obtained the same results

  16. Validation of the finite element simulation to estimate the rolling resistance of a non-driving wheel with experimental tests

    Directory of Open Access Journals (Sweden)

    N Dibagar

    2015-09-01

    rubber materials for the tire. Tire model consisted of three components: tread, rubber and ring. Using a soil bin and one wheel tester with their related equipment, experimental tests were carried out in the workstation of mechanics of bio system engineering department of the Urmia University. This system includes various sections such as soil storage in dimensions of 22×2×1 meter, tools carrier or tracker, soil processing equipment, dynamic system, evaluation tools and controlling systems. In order to launch the collection and supply required power for wheel carrier, an industrial three phase electromotor with 22 kW (30 hp was used. Both numerical and experimental tests were done at three levels of wheel dynamic load (1, 2, 3, 4 and 5 kN, tire inflation pressure (100, 200 and 300 kPa and four levels of speed (0.25, 0.45, 0.65, 0.9 and 1.15 m s-1 to obtain the rolling resistance of the tire. Results and discussion: In order to evaluate the performance of final non driving tire-soil model to estimate the rolling resistance, numerical results were compared with preliminary experimental data obtained from the soil-bin tests. The comparison showed reasonably good agreement between the computed and measured general pattern of the rolling resistance at the tire-soil interface under different speeds, vertical loads and inflation pressures. In both tests, a specified relation was not seen between tire velocity and its rolling resistance, as it was not seen in empirical models such as Wismar and Luce. Correlation coefficient between experimental and numerical data, in the minimum and maximum value of tire inflation pressure was computed to be 0.06 and 0.016 percent, respectively. The amount of tire rolling resistance significantly increased with increase of tire vertical load. Correlation coefficient between experimental and numerical data, in the minimum and maximum vertical loads was computed to be 80 and 87 percent, respectively. Gent and Walter obtained the same results

  17. Hand on the wheel, mind on the mobile: an analysis of social factors contributing to texting while driving.

    Science.gov (United States)

    Seiler, Steven J

    2015-02-01

    In an era defined by social technology, mobile phones provide constant connection to others. However, they also present a very dangerous situation when people choose to use their mobile phones while driving. In particular, exchanging text messages while driving has resulted in numerous accidents and fatalities. The purpose of this study is to examine social factors that lead people to text while driving. Specifically, using a multivariate logistic regression analysis of data from a 2010 survey by the Pew Research Center, variables for general mobile talk, driving while talking on a mobile, using the Internet on a mobile, sexting, and various motivations for texting were examined to determine factors that increase the likelihood of texting while driving. The findings suggest that people engage in mobile multiplexing (i.e., communication using two or more media on the mobile) while driving. Additionally, exchanging text messages in public, and consequently texting while driving, has become normalized. Furthermore, people are socialized into such behaviors through observing others texting while driving and using a mobile recklessly while driving. Finally, a number of motivations for texting were found to increase the likelihood of texting while driving significantly. Ultimately, the author contends that texting while driving has become a cultural artifact in the United States, which conflicts with driver safety as well as laws prohibiting texting while driving. The findings of this study could inform future awareness campaigns and technology developers to help establish a safer driving environment within the multitasking culture.

  18. 电动轮车电子差速控制的试验研究%Experimental Research of Electronic Differential Control for In-wheel Motor Drive Electric Vehicle

    Institute of Scientific and Technical Information of China (English)

    喻厚宇; 黄妙华; 张振国

    2011-01-01

    The in-wheel motor drive electric vehicle is a novel electric vehicle and the electronic differential control is one of its key technologies. For the low speed four-wheel independent drive electric vehicle, the differential relationship among four wheels is analyzed according to the Ackerman steer model, and then is determined through the push and steer test at different steering wheel angles. The electronic differential among four wheels is achieved through four parallel PID control closed loops of in-wheel motor speed. The proposed electronic differential control based on the differential relationship among four wheels determined through the push and steer test for the in-wheel motor drive electric vehicle is validated through the actual road test.%电动轮车是一种新型的采用电动轮驱动的电动汽车,电子差速控制是其关键技术之一.针对4轮独立驱动的低速电动轮车,在利用Ackerman转向模型对其转向时的4轮差速关系进行理论分析的基础上,通过推行转向试验确定了不同方向盘转角时的4轮差速关系,据此采用四路并行的轮边电机转速PID闭环控制实现了4轮的电子差速.实际道路工况的实车试验验证了所提出的基于推行转向试验确定4轮差速关系的电动轮车电子差速控制方法的有效性.

  19. Getting Behind the Wheel

    Institute of Scientific and Technical Information of China (English)

    SEAN; O’CONNER

    2008-01-01

    I took the cramming school,the conveyor belt approach to learning to drive.As a passed and stamped graduate of the Oriental Fashion Driving School,I’m relieved that I no longer have to get up at 5 o’clock for a 7-to-12 seat behind the wheel

  20. Design of the Automatic Four-wheel Driving and Four-wheel Steering Chassis’ s Electric Control System%四轮驱动四轮转向自动驾驶底盘的电控系统设计

    Institute of Scientific and Technical Information of China (English)

    李玫瑾; 魏新华

    2016-01-01

    为了提高植保机械作业精度、降低驾驶员操作难度,设计了一种高地隙全液压四轮驱动四轮转向自动驾驶底盘。本文介绍了底盘的整体结构,重点阐述了电控系统的结构与工作原理。该电控系统以EPCS-8980为上位机、DSP56F805信号控制器为核心、基于CAN 总线进行通讯,行车状态参数采集器接收各传感器采集的行车参数信息,并通过 CAN 总线发送到车载电脑和行车控制器,行车控制器根据车载电脑指令和各传感器参数,按照行车控制模型生成控制指令,并通过各电磁阀独立控制4个液压马达和4个转向油缸,实现底盘的行车控制。同时,对电控系统进行了测试,测试结果表明:该电控系统实现了对液压元器件的控制,保证了其运行的可靠性,可满足实际作业要求,同时该电控系统也可用于通用自主移动平台上。%In order to improve the accuracy of plant protection machinery operations , and reduce the difficulty of driver ’ s operations, this paper presents a high clearance full hydraulic and automatic four-wheel driving and four-wheel steer-ing chassis .The overall structure of the chassis was produced , and also the electric control system was mainly presented . The electric control system was designed with its vehicular computer EPCS-8980,core part DSP56F805, communication via CAN-bus.The driving parameters were collected by each sensor , and each sensor signals collected by the driving da-ta collector transmitted to the vehicular computer and the driving controller via CAN-bus.According to instructions of the vehicular computer and the parameters of the sensors , the driving controller generated the controlling instruction under the traffic controlling model , the four hydraulic motors and the four steering cylinders were controlled by each electromagnetic valve , and thus the chassis could be controlled to drive and steer .The tests of the

  1. TCS Strategy for Four-wheel Drive Vehicle%四轮驱动汽车 TCS 控制策略研究

    Institute of Scientific and Technical Information of China (English)

    王顺民; 邓亚东

    2015-01-01

    提出了一种控制发动机输出力矩和轴间扭矩分配的控制策略,并添加行驶工况识别模块,针对不同工况制定了不同的控制策略,使四轮驱动汽车能够充分利用路面附着系数。以控制驱动车轮滑移率为目标,在TESIS-DYNAware中建立发动机节气门控制模型及轴间转矩分配系统控制模型,并进行有无牵引力控制系统的直线加速对比仿真试验。试验结果表明,所建牵引力控制策略可有效抑制驱动轮滑转,提高汽车动力性能。%A strategy which controls the output of engine torque and the distribution between the axle torques was proposed to fully use the road friction.The switch model of dynamic condition was established;which contains different strategy to control the vehicle.A dynamic model on four-wheel-drive vehicle was established in TESIS -DYNAware.It was a real time simulation platform.Through modifying and establishing the Simulink model of engine control and inner-axle torque control, a simulation test was running with and without the control system.The result shows that Torque Control System ( TCS) can restrain the slip rate of the drive wheels.

  2. Behind the wheel and on the map: Genetic and environmental associations between drunk driving and other externalizing behaviors.

    Science.gov (United States)

    Quinn, Patrick D; Harden, K Paige

    2013-11-01

    Drunk driving, a major contributor to alcohol-related mortality, has been linked to a variety of other alcohol-related (e.g., Alcohol Dependence, early age at first drink) and non-alcohol-related externalizing behaviors. In a sample of 517 same-sex twin pairs from the National Longitudinal Study of Adolescent Health, we examined 3 conceptualizations of the etiology of drunk driving in relation to other externalizing behaviors. A series of behavioral-genetic models found consistent evidence for drunk driving as a manifestation of genetic vulnerabilities toward a spectrum of alcohol-related and non-alcohol-related externalizing behaviors. Most notably, multidimensional scaling analyses produced a genetic "map" with drunk driving located near its center, supporting the strength of drunk driving's genetic relations with a broad range of externalizing behaviors. In contrast, nonshared environmental associations with drunk driving were weaker and more diffuse. Drunk driving may be a manifestation of genetic vulnerabilities toward a broad externalizing spectrum. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  3. 六轮电驱动铰接车行驶状态功率流试验%Power Flow Experiment and Analysis of Driving States on Six-wheel Electric Drive Articulated Vehicle

    Institute of Scientific and Technical Information of China (English)

    钟恒; 陈树新

    2012-01-01

    定性分析了六轮独立电驱动、并联运行铰接车不同行驶状态下无跟随控制的整车功率流状态.建立了系统功率流模型和轮边电动机功率矩阵,采用功率键合图法和归一化功率矩阵描述了系统功率流.试验以转矩为调节目标,采用调压的方式模拟永磁同步电动机并联运行的功率流状态.试验分析表明直线行驶和电制动时两侧轮电机牵引和制动功率分配均衡;转角较大时外侧轮电动机再生发电并产生制动转矩,内侧轮电机负荷加重,滑转率增大,轮速比系数kn随着转向角的增大而增大,功率比系数kp随之减小,载荷大小对kn的影响不大,转矩比系数kT为后桥大于前桥且重载大于轻载;打滑轮电动机转速增大而转矩减小,行驶稳定性变差.%The qualitative analysis of system power flow was made for articulated vehicle which had six independently-electric-driving wheels running in parallel under different driving states without following control. The system power flow mode] and wheel-motor power matrix were established. System power flow was described by using power bond graph and normalized power matrix. Taking torque as the control target, the test was pcrformed to simulate the powcr flow state of permanent magnet synchronous motors running in parallel by means of adjusting voltage. Test analysis showed that the traction and braking power of the wheel-motor on both sides were equal when driving and electric braking straightly. The outside wheel-motors ran into regeneration state and produced braking torque when steering angle was large, then inside wheel-motors' load were aggravating and theirs slip ratio increased. Speed ratio kn increased with the increasing of steering angle, but power ratio Ap decreased at the same time. The severity of load had little effect on kn, Torque ratio kT of the rear axle was larger than the front axle and overload state was larger than light load state.

  4. Direct Yaw-Moment Control of All-Wheel-Independent-Drive Electric Vehicles with Network-Induced Delays through Parameter-Dependent Fuzzy SMC Approach

    Directory of Open Access Journals (Sweden)

    Wanke Cao

    2017-01-01

    Full Text Available This paper investigates the robust direct yaw-moment control (DYC through parameter-dependent fuzzy sliding mode control (SMC approach for all-wheel-independent-drive electric vehicles (AWID-EVs subject to network-induced delays. AWID-EVs have obvious advantages in terms of DYC over the traditional centralized-drive vehicles. However it is one of the most principal issues for AWID-EVs to ensure the robustness of DYC. Furthermore, the network-induced delays would also reduce control performance of DYC and even deteriorate the EV system. To ensure robustness of DYC and deal with network-induced delays, a parameter-dependent fuzzy sliding mode control (FSMC method based on the real-time information of vehicle states and delays is proposed in this paper. The results of cosimulations with Simulink® and CarSim® demonstrate the effectiveness of the proposed controller. Moreover, the results of comparison with a conventional FSMC controller illustrate the strength of explicitly dealing with network-induced delays.

  5. Wheels, skills and thrills: a social marketing trial to reduce aggressive driving from young men in deprived areas.

    Science.gov (United States)

    Tapp, Alan; Pressley, Ashley; Baugh, Mike; White, Paul

    2013-09-01

    Young men from poorer backgrounds are associated with high road traffic collision levels. However, solving this problem has proven very difficult. Hence this paper summarises the findings of a UK government funded two-year trial of a cross-discipline intervention to reduce aggressive driving amongst this group. The intervention reported on here departed from traditional approaches such as fear appeals, stand-alone educational approaches, or punitive measures. Instead, the discipline of social marketing was used to provide overarching direction and structure for the trial, with a key focus on motivation and engagement. The project rested on a strong education and training platform and included a bespoke coaching programme, incentives, and an in-vehicle measurement and feedback device. The project had three development phases leading to the final trial. First, a literature and case study review identified possible design strategies. Second, these strategies were explored using primary research in the form of a qualitative inquiry. Third, a pre-trial design phase sought to introduce key components of the intervention to the trial cohort, retaining some flexibility before committing to the final design. Young males with a history of challenging behaviour (e.g. criminal records, driving convictions) from an economically deprived area within a UK city were recruited. Of 42 recruits, 23 successfully completed the trial. Behaviour changes were measured pre-, during and post-trial through a combination of driver performance data measured by in-vehicle data recorders (IVDRs), assessments of driving undertaken by trained observers, and self-assessment surveys and interviews with trial participants. Results indicate a significant average improvement in driving skills amongst participants who completed the trial. Given the difficulty in engaging and changing behaviour of this specific group, this is regarded as a significant finding. In summary the study provides an indication

  6. Weed or wheel! FMRI, behavioural, and toxicological investigations of how cannabis smoking affects skills necessary for driving.

    Directory of Open Access Journals (Sweden)

    Giovanni Battistella

    Full Text Available Marijuana is the most widely used illicit drug, however its effects on cognitive functions underlying safe driving remain mostly unexplored. Our goal was to evaluate the impact of cannabis on the driving ability of occasional smokers, by investigating changes in the brain network involved in a tracking task. The subject characteristics, the percentage of Δ(9-Tetrahydrocannabinol in the joint, and the inhaled dose were in accordance with real-life conditions. Thirty-one male volunteers were enrolled in this study that includes clinical and toxicological aspects together with functional magnetic resonance imaging of the brain and measurements of psychomotor skills. The fMRI paradigm was based on a visuo-motor tracking task, alternating active tracking blocks with passive tracking viewing and rest condition. We show that cannabis smoking, even at low Δ(9-Tetrahydrocannabinol blood concentrations, decreases psychomotor skills and alters the activity of the brain networks involved in cognition. The relative decrease of Blood Oxygen Level Dependent response (BOLD after cannabis smoking in the anterior insula, dorsomedial thalamus, and striatum compared to placebo smoking suggests an alteration of the network involved in saliency detection. In addition, the decrease of BOLD response in the right superior parietal cortex and in the dorsolateral prefrontal cortex indicates the involvement of the Control Executive network known to operate once the saliencies are identified. Furthermore, cannabis increases activity in the rostral anterior cingulate cortex and ventromedial prefrontal cortices, suggesting an increase in self-oriented mental activity. Subjects are more attracted by intrapersonal stimuli ("self" and fail to attend to task performance, leading to an insufficient allocation of task-oriented resources and to sub-optimal performance. These effects correlate with the subjective feeling of confusion rather than with the blood level of Δ(9

  7. Weed or Wheel! fMRI, Behavioural, and Toxicological Investigations of How Cannabis Smoking Affects Skills Necessary for Driving

    Science.gov (United States)

    Thomas, Aurélien; Mall, Jean-Frédéric; Chtioui, Haithem; Appenzeller, Monique; Annoni, Jean-Marie; Favrat, Bernard

    2013-01-01

    Marijuana is the most widely used illicit drug, however its effects on cognitive functions underling safe driving remain mostly unexplored. Our goal was to evaluate the impact of cannabis on the driving ability of occasional smokers, by investigating changes in the brain network involved in a tracking task. The subject characteristics, the percentage of Δ9-Tetrahydrocannabinol in the joint, and the inhaled dose were in accordance with real-life conditions. Thirty-one male volunteers were enrolled in this study that includes clinical and toxicological aspects together with functional magnetic resonance imaging of the brain and measurements of psychomotor skills. The fMRI paradigm was based on a visuo-motor tracking task, alternating active tracking blocks with passive tracking viewing and rest condition. We show that cannabis smoking, even at low Δ9-Tetrahydrocannabinol blood concentrations, decreases psychomotor skills and alters the activity of the brain networks involved in cognition. The relative decrease of Blood Oxygen Level Dependent response (BOLD) after cannabis smoking in the anterior insula, dorsomedial thalamus, and striatum compared to placebo smoking suggests an alteration of the network involved in saliency detection. In addition, the decrease of BOLD response in the right superior parietal cortex and in the dorsolateral prefrontal cortex indicates the involvement of the Control Executive network known to operate once the saliencies are identified. Furthermore, cannabis increases activity in the rostral anterior cingulate cortex and ventromedial prefrontal cortices, suggesting an increase in self-oriented mental activity. Subjects are more attracted by intrapersonal stimuli (“self”) and fail to attend to task performance, leading to an insufficient allocation of task-oriented resources and to sub-optimal performance. These effects correlate with the subjective feeling of confusion rather than with the blood level of Δ9-Tetrahydrocannabinol

  8. New steering mechanism for wheeled mobile robots

    Institute of Scientific and Technical Information of China (English)

    Sidibe Marie Bernard; FU Yi-li; XU He; MA Yu-lin

    2007-01-01

    A new castor wheel mechanism for omni-directional mobile platform is presented. A motion of translation is transformed into a rotation to steer the wheel with the help of a helical path fits into a translation joint and three rollers whose axes are connected to the driving shaft of the wheel. When the path moves in translation it acts on the rollers for steering. The path-roller friction transmission, the wheel kinematics and the maneuverability have been analyzed.

  9. Development of control system for two-wheel drive mobile robot%两轮驱动移动机器人控制系统的研制

    Institute of Scientific and Technical Information of China (English)

    李瑞峰; 黄超; 孙中远

    2011-01-01

    A control system for two-wheel drive mobile robot is described in it ,which is based on TMS320F2812 chip, The aim is to drive the mobile robot to turn left,righ ,forward,rewind and so on by precisely controlling of motor, during which a closed-loop control for motor speed and position have been completed and some basic movements of the mobile robot could be achieved through setting motor speed and position.If you want to obtain current position and orientation coordinates of mobile robot, DSP could help through processing the data of motor from which you may draw an actual trajectory according to position coordinates.And the motion effect of the mobile robot could be seen through the drawing.%描述了两轮驱动移动机器人的控制系统,它以控制芯片TMS320F2812为基础,通过对电机的精确控制来实现移动机器人的左转、右转、前进、后退等功能,在电机控制中,完成了对速度和位置的闭环控制,通过对电机的速度和位置的设定,可以实现移动机器人的一些基本的运动功能.DSP通过对电机数据进行处理,得到当前移动机器人的位姿坐标,取其中的位置坐标画出实际轨迹图,通过该图来看移动机器人的运动效果.

  10. Design and test of drive and control system for electric wheeled mobile car%电动轮式移动小车控制系统设计与试验

    Institute of Scientific and Technical Information of China (English)

    张铁民; 黄翰; 黄鹏焕

    2014-01-01

    为了实现电动轮式移动小车能在实际不同的负载和路况下可以稳定的运行工作,该文研制了小车的四轮独立驱动的电机驱动和四轮转向控制系统,该系统由主控制芯片STM32F103RCT6对移动小车进行解算得出4个驱动轮的速度,然后对每个驱动电机进行转矩分配,控制4台用于驱动的无刷直流轮毂电机、2台转向直流电机以及2台制动用直流电机,使得小车实现直线行驶、转向和原地转向;通过单片机ATMEGA48PA控制4台无刷直流轮毂电机换相;采用驱动芯片IR2113驱动场效应管FQA140N10,并利用电机内部霍尔传感器输出的脉冲信号检测无刷直流电机的速度,采用放大器LM358搭建过载保护电路。试验结果表明,所开发的小车驱动控制系统实现了四轮电子差速与转矩分配,移动小车能在水泥路面、干泥土路面、斜坡和草地上稳定可靠运行,小车限速20 km/h,爬坡度为8°。在空载情况下能匀速运行8~10 h,带额定负载250 kg情况下能匀速运行4~5 h,有较好的负载性能,满足农业运输及农田作业的需求,减轻人的体力劳动,提高生产效率。该研究可为应用于田间作业的电动移动小车的机械设计及电气控制系统设计提供参考。%Electric wheeled mobile car plays an important role in agricultural production, but when the mobile car’s loads or road conditions change, the drive motor controller of the existing wheeled mobile car is difficult to control the motor efficiently and in real time, leading to difficulties in modularization and productization. Therefore, on the basis of the architecture developed in laboratory, a system for driving and controlling the motor of the car was developed, and a master-slave control system structure based on the main control chip STM32F103RCT6 and the underlying motor control chip ATMEGA48PA was proposed. In this paper, the drive control system

  11. 轮式移动机器人电机驱动系统的研究与开发%Design and research on motor driving system of wheeled mobile robot

    Institute of Scientific and Technical Information of China (English)

    韩军; 常瑞丽

    2011-01-01

    以嵌入式运动控制体系为基础,以移动机器人为研究对象,结合三轮结构轮式移动机器人,对二轮差速驱动转向自主移动机器人运动学和动力学空间模型进行了分析和计算,研究和设计了自主移动机器人电机驱动系统,开发了一套二轮差速驱动转向移动机器人电机驱动系统,完成了系统各部件的整体装配和调试.试验结果表明,该设计方案可行、系统运行稳定可靠、成本低廉、所用元件易于购置,具有较好的实用的价值和应用前景.%Taking embedded control system as the foundation and mobile robot as the research ob-ject,the kinematics and dynamics space models of the autonomous mobile robot which is swerved by differ-ential driving for 2 driving wheels are analyzed and calculated, combining the wheeled mobile robot with three wheels.Then the motor driving system of mobile robot is researched and designed and a motor driving system for autonomous mobile robot which is swerved by the differential driving for the 2 driving wlveels is developed.Afterwards the whole assembly of all components and system debugging are accomplished.The results of experiments show that the design scheme is viable, and the system is stable and reliable at work with its lower cost and easy for component purchase, which is valuable in practice and in application.

  12. Bicycle Wheel

    Science.gov (United States)

    1991-01-01

    An aerodynamic bicycle wheel developed by two DuPont engineers and a California company incorporates research into NASA airfoils. Computer modeling was accomplished with MSC/NASTRAN. Each of the three spokes in the wheel is, in effect, an airfoil, maximizing aerodynamic efficiency for racing.

  13. Design and experiment of four-wheel independent steering driving and control system for agricultural wheeled robot%农用轮式机器人四轮独立转向驱动控制系统设计与试验

    Institute of Scientific and Technical Information of China (English)

    张京; 陈度; 王书茂; 胡小安; 王冬

    2015-01-01

    针对一般农用轮式机器人转向方式单一、难以适应田间复杂作业环境以及推广应用成本较高等问题,该文设计了一种农用轮式机器人四轮独立转向驱动控制系统,采用模块化设计方法构建了该控制系统的底层硬件部分,结合控制器局域网络(controller area network, CAN)总线、串口通讯和传感器技术实现了该机器人移动轮转角、转速等数据的采集功能且应用了有效的硬件电路隔离保护方案;基于低速阿克曼四轮转向模型与比例积分微分(proportion, integration, differentiation, PID)控制算法分析并验证了该机器人四轮独立转向驱动控制策略的有效性。试验结果表明:该机器人能够通过上位机或遥控器实现其四轮独立转向与转速控制功能,移动轮在0~360°转向过程中,控制效果鲁棒性强、稳定且转角控制的最大平均绝对误差为0.10°,通过上位机设定转速后经0.5~1 s左右,移动轮转速达到稳态,并具有较高转速控制精度。该研究为农用轮式机器人的四轮独立转向驱动控制方法提供了参考。%Aiming at the problem of agricultural wheeled robots such as single steering mode, being difficult to adapt to the complex operating environment in field, higher cost for promotion and application, this paper designed a four-wheel independent steering driving and control system for the agricultural wheeled robot. The mechanical body of agricultural wheeled robot was composed of 3 parts, which mainly included robot walking chassis, power supply system, and electrical and computer control system. The robot walking chassis adopted the structure with high ground clearance which not only ensured the farmland operation, but also optimized the function of four-wheel independent steering driving and control system. Furthermore, the agricultural wheeled robot was also equipped with a battery, BLDC (brushless direct current) driver

  14. 轮毂电机驱动车辆转向控制策略%Research on Steering Control Strategy for In-Wheel Motor Drive Vehicle

    Institute of Scientific and Technical Information of China (English)

    刘春光; 阳贵兵; 廖自力; 李嘉麒

    2016-01-01

    为提高轮毂电机驱动车辆转向机动灵活性以及安全稳定性,提出了一种基于直接横摆力矩控制的转向控制策略。以带有双桥转向机构的8轮轮毂电机驱动车辆为研究对象,研究其双重转向控制问题,建立基于车辆二自由度单轨模型的车辆参考模型,并以横摆角速度作为控制变量,建立基于横摆力矩PID控制器和横摆力矩分配控制器的转向分层控制模型。利用硬件在环实时仿真实验对所提出的转向控制策略的可行性和有效性进行分析验证。%In order to improve the steering flexibility,security and stability of the in-wheel motor drive vehicle,a steering control strategy based on DYC (Direct Yaw Moment Control)is established. The double-axle steering mechanism is taken as an object of study for its dual steering control. A vehicle model is established based on a monorail model with 2 degree of freedom. And a hierarchical control model based on PID controller and yaw moment distribution controller,in which the yaw angular velocity is chosen to be a controlling variable. The steering control strategy established in this paper is proven to be feasible and effective through the HIL(Hardware-in-Loop)real time simulation.

  15. 四驱混合动力轿车分布式卡尔曼车速估计%Vehicle Speed Estimation Based on Distributed Kalman Filter for Four Wheel Drive Hybrid Electric Car

    Institute of Scientific and Technical Information of China (English)

    赵治国; 杨杰; 吴枭威

    2015-01-01

    The driving mode of hybrid electric car can be two-wheel or four-wheel drive. The speed estimation designed for a specific driving mode can hardly achieve high estimated accuracy in all modes. Focus on the changeable driving mode, a kind of distributed Kalman filter with two levels is proposed, by means of utilize vehicle sensors signals, the driving torque of rear in-wheel motors and the torque of front driving wheels at the given gear state. Considering the strongly nonlinear of the model, UKF is adopted to design the filter, and to improve the filter’s robustness on modeling error and signal noise, measurement noise mean and covariance is self-adaptive. Firstly, based on UniTire Model and recursive equation of slip rate, the sub-filter is developed; secondly, based on the vehicle Kinematics model, the master-filter can be developed; at last, in consideration of different driving modes, a more accurate velocity estimation is obtained by fusing information from each sub-filters. With the help of Carsim and Simulink, the simulation platform about four wheel drive hybrid electric car is developed, and the proposed speed estimation algorithm is tested on this platform under the pure electric drive mode and the hybrid drive mode. The results show that the proposed algorithm has not only high precision, but also strong robustness on modeling error, measurement noise and the changeable driving mode.%四驱混合动力轿车存在两轮/四轮多种驱动模式,针对某一驱动模式所设计的车速估计算法难以满足其他模式下车速估计的精度。考虑车辆不同驱动模式,利用车载传感器信号、后轮毂电机转矩信息以及既定档位下前轮转矩信息,提出两级分布式卡尔曼车速估计方法。考虑模型的强非线性,采用无味卡尔曼滤波(Unscented Kalman filter,UKF)算法设计主/子滤波器。同时为了提高UKF算法对模型误差、信号干扰的鲁棒性,实现了量测噪声均值和方

  16. A new type suspension design suitable for an in-wheel motor driving system%适合轮毂电机驱动的新型悬架系统设计

    Institute of Scientific and Technical Information of China (English)

    陈龙; 董红亮; 李利明

    2015-01-01

    针对轮毂电机占用轮内空间,导致前悬架无法布置的问题,以麦弗逊式悬架为基础,将原来的单个下控制臂改为两个独立的控制臂,得到了适合轮毂电机驱动的新的悬架构型。建立了新型悬架系统前轮定位参数的理论计算模型和多体动力学模型,并进行了分析验证。通过新型悬架系统硬点位置优化设计,得到合适的前轮定位参数。该悬架构型为轮毂电机提供了足够的轮内空间,设计灵活,并且能最大限度的沿用麦弗逊式悬架的部件,解决了传统悬架不适合轮毂驱动的难题。%Due to the bigger in-wheel space occupied by an in-wheel motor,the traditional front suspension cannot be installed.Therefore,a new suspension system for in-wheel motor driving was developed by changing McPherson suspension's single lower control arm to two separate control arms.The theoretical calculation model and the multi-body dynamic model for the new suspension system's front wheel positioning parameters were built and analyzed,respectively. Through the optimization of the hard point locations of the new suspension system,its suitable front wheel positioning parameters were obtained.The new suspension provided an enough in-wheel space for installation of an in-wheel motor. Meanwhile,most of the original components could be used continuously.

  17. Effects of Motor Faults on Traction Performances of Lunar Rover' s Driving Wheels%电机故障对月球车驱动轮牵引性能的影响

    Institute of Scientific and Technical Information of China (English)

    王立; 刘景林; 吴喜桥

    2012-01-01

    月球车是一种在外太空极端恶劣环境下长时间自主运行、不可维修的轮式移动机器人,为准确预测车轮驱动电机故障运行时的牵引性能对于月球车的可靠性有重要意义.为确保月球车顺利完成任务,建立了电机正常运行时的电磁场仿真模型,在模型基础上针对开关管短路、开关管开路、霍尔位置信号恒值和绕组开路等分别建立了故障仿真模型,通过仿真确定了能够识别各种故障的特征波形,并绘制了电机的机械特性曲线.应用车辆地面力学理论对比分析了电机正常与故障运行时驱动轮牵引性能的变化.研究结果表明,当电机发生各种故障后,驱动轮的牵引性能均有不同程度的下降.可为带障运行条件下的多轮协调控制策略的制定提供了理论依据.%The lunar rover is a type of wheeled mobile robot which operates autonomously under the harsh space environment for a very long time and can not been properly maintained. It is important to study the traction perform-ances of driving wheels with faulty motors for research on the lunar rover's operational reliabilities. An electromagnet-ic field simulation model of the wheel motors under normal state was built based on Flux 10.3 and was modified to ac-commodate multifarious faults including switch faults, Hall sensor signal faults and winding faults. The characteristic waveforms for diagnosing the faults and the mechanical characteristic curves of the faulty motors were obtained in vir-tue of electromagnetic field simulation. The traction performances of driving wheels with natural and faulty motors were studied based on the wheel-terrain interaction model between rigid wheel and floppy soil. The results indicate that the traction capacities of lunar rover driving wheels with faulty motors diminished in different levels, which can provide some theoretical foundations for research on operational reliabilities and coordination control methods

  18. Kinematics and dynamics modelling of a mecanum wheeled mobile platform

    CSIR Research Space (South Africa)

    Tlale, NS

    2008-12-01

    Full Text Available velocity of the mecanum wheel is determined as: _ = n _ m sin (1) where _ m is the rotational velocity of the DC motor that is driving the mecanum wheel and n is the gear ratio of the DC motor driving the mecanum wheel. The rotational velocity of each... wheels and the gear ratio of the DC motors used, m is the change in the number of encoder pulses for wheel and T is the time interval of sampling encoder pulses. The effectiveness of the motor, e, in converting the driving motor?s rotational...

  19. A fly-wheel drive with controlled-torque clutch for a reactors cooling circuit pumps; Entrainement des pompes du circuit de refrigeration d'un reacteur par volant a embrayage sous couple controle

    Energy Technology Data Exchange (ETDEWEB)

    Riettini, A. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1964-10-15

    After a theoretical study on the slowing down of a centrifugal pump, the motion equations have been checked by means of experimental tests. In order to have important slowing down times (which is the case of the cooling pumps of a research reactor) it is necessary to add a fly-wheel. To prevent troubles when starting, a block pump-fly-wheel with clutch under controlled torque was developed. It is so possible to start the fly-wheel progressively without increasing too much power of the driving motor. (author) [French] Apres une etude theorique sur le mouvement de ralentissement d'une pompe centrifuge, les equations du mouvement ont ete verifiees par des essais pratiques. Pour obtenir des temps de ralentissement importants (cas des pompes de refrigeration d'un reacteur de recherche) il est necessaire d'y adjoindre un volant d'inertie. Pour eviter les inconvenients au demarrage, on a etudie un ensemble pompe-volant avec embrayage sous couple controle. Cette solution permet de lancer progressivement le volant sans augmentation appreciable de la puissance du moteur d'entrainement. (auteur)

  20. 基于改进遗传算法的微型电动车轮毂电机优化设计%Optimization design of driving in-wheel motor of micro-electric vehicle based on improvement genetic algorithm

    Institute of Scientific and Technical Information of China (English)

    陈齐平; 舒红宇; 任凯; 陈里敏; 陈博; 谢安源

    2012-01-01

    In order to acquire a high efficiency and low cost in-wheel motor of micro-electric vehicle, a new driving in-wheel motor was optimized and designed. The simple genetic algorithm and pattern search method applied in driving in-wheel motor of the optimum design were introduced. The disadvantages of these two methods that the effects of optimization design were non-significant were pointed out, and an improvement genetic algorithm based on these was put forward. On the basis of the study of the in-wheel motor of micro-electric vehicle and in the light of the design features of driving in-wheel motor, a new mathematical model of driving in-wheel motor optimization design was established, and a living example was optimized and computed. The results show that the efficiency of the driving in-wheel motor is improved, and the cost are decreased, which can satisfy the using requirements of driving in-wheel motor of micro-electric vehicle. Therefore, the improvement genetic algorithm is an ideal algorithm in optimization design of driving in-wheel motor, which has a wide range of engineering application.%为了获得高效率和低成本的微型电动车轮毂电机,优化设计一种新型驱动轮毂电机.介绍简单遗传算法和模式搜索法在驱动轮毂电机优化设计中的应用,针对它们优化设计效果不显著的缺点,提出一种改进的遗传算法.在对微型电动车轮毂电机进行研究的基础上,针对驱动轮毂电机设计特点,重新建立驱动轮毂电机优化设计数学模型,并以实例进行优化计算.研究结果表明:驱动轮毂电机的效率提高,成本降低,能满足微型电动车对驱动轮毂电机的使用要求,因此,对于驱动轮毂电机的优化设计,改进遗传算法是一种比较理想的算法,具有广阔的 工程应用价值.

  1. Analysis and Design of a Permanent Magnet Bi-Stable Electro-Magnetic Clutch Unit for In-Wheel Electric Vehicle Drives

    Directory of Open Access Journals (Sweden)

    Wanli Cai

    2015-06-01

    Full Text Available Clutches have been used in internal combustion vehicles and concentrated electric vehicles (EVs to smoothen impulsion while starting and shifting. This paper proposes a permanent magnet bi-stable electromagnetic clutch unit (PMBECU which is specially introduced into in-wheel EVs to make the rigid connection between hub and wheel more flexible. Firstly, the operation principle of the PMBECU is illustrated. Then, the basic magnetic circuit model is presented and analyzed, followed by optimal design of the main structural parameters by investigating the PM leakage flux coefficient. Further, according to the basic electromagnetic characteristics of the PMBECU, the current pulse supply is put forward, and the minimum pulse width which enables the operation of the PMBECU and its dynamic characteristics are analyzed by an improved finite element method. Finally, a prototype machine is manufactured and tested to validate all the analysis results.

  2. Word wheels

    CERN Document Server

    Clark, Kathryn

    2013-01-01

    Targeting the specific problems learners have with language structure, these multi-sensory exercises appeal to all age groups including adults. Exercises use sight, sound and touch and are also suitable for English as an Additional Lanaguage and Basic Skills students.Word Wheels includes off-the-shelf resources including lesson plans and photocopiable worksheets, an interactive CD with practice exercises, and support material for the busy teacher or non-specialist staff, as well as homework activities.

  3. Desempenho operacional de trator com tração dianteira auxiliar na subsolagem de um inceptisol Performance of a front wheel drive tractor in the subsoiling operation in an inceptisol

    Directory of Open Access Journals (Sweden)

    Neyton de Oliveira Miranda

    2000-04-01

    Full Text Available Na subsolagem de um solo da ordem dos Inceptisol (Cambissolos usando um trator com tração dianteira auxiliar, foram comparados pneus de duas idades, duas rotações do motor e duas marchas, além do uso ou não do bloqueio do diferencial. Mediram-se velocidade de deslocamento, patinagem das rodas traseiras, tempo operacional teórico e consumo de combustível por hora e por área trabalhada. O uso do bloqueio do diferencial não influiu significativamente em nenhum parâmetro estudado e o de pneus novos resultou em desempenho do trator superior em relação aos pneus desgastados, para todos os parâmetros estudados. A rotação do motor de 1.800 rpm reduziu a patinagem e o consumo de combustível por hora e por área trabalhada em relação a 2.000 rpm, enquanto o uso da quarta marcha reduziu o tempo operacional teórico e o consumo de combustível por área trabalhada em relação à terceira marcha.In the subsoiling operation in an Inceptisol with a front wheel drive tractor, worn and new tyres, two engine speeds, two gear ratios and the use or not of the differential lock, were compared. Travel speed, rear wheel slip, theoretical field time, and fuel consumption per hour as well as per worked area were measured. The differential lock did not influence significantly any studied parameter. New tires were superior to worn ones for all parameters. Engine speed of 1800 rpm reduced wheel slip, fuel consumption per hour and per hectare compared with 2000 rpm. Fourth gear reduced the theoretical field time and fuel consumption per hectare compared to third gear.

  4. Fifth wheel

    Science.gov (United States)

    Albrecht, W. P.; Sparks, R. H. (Inventor)

    1976-01-01

    An improved fifth wheel for a tractor trailer rig, characterized by a first subassembly including a wear plate was developed and modified to be mounted on a downwardly facing surface of a trailer. A king pin projected normally therefrom, and a second subassembly is adapted to be pivotally mounted on an upwardly facing surface of a tractor. The king pin is brought into contiguous relation with the first sub assembly. A receiver for capturing the king pin is included along with a safety means responsive to a failure of the king pin or its latching mechanism for joining the first subassembly with the second subassembly.

  5. Longitudinal force estimation for motorized wheels driving electric vehicle based on improved closed-loop subspace identification%基于改进闭环子空间辨识的电动轮汽车纵向力估计

    Institute of Scientific and Technical Information of China (English)

    徐兴; 陈特; 陈龙; 王吴杰

    2016-01-01

    In order to realize the control and coordinated allocation of tire longitudinal force for motorized wheels driving electric vehicle,a longitudinal force estimation method was proposed based on improved closed-loop subspace identification.The characteristics of electric drive system of motorized wheels driving vehicle was analyzed to propose a longitudinal force estimation model.The road simulation test on chassis dynamometer was carried out, and the experimental data were collected. The subspace identification algorithm N4SID was deviated when model input and noise were correlated.To solve the problem,an improved closed-loop subspace identification method was investigated.The results show that compared with N4SID identification method,the improved closed-loop subspace identification method has better anti-interference ability with higher longitudinal force estimation accuracy and better real-time tracking capability,which can meet the requirements of driving force model predictive control based on data driving.%为实现电动轮汽车轮胎纵向力的控制与协调分配,提出了基于改进闭环子空间辨识的电动轮汽车纵向力估计方法。分析了电动轮汽车电驱动系统特性,在此基础上提出了用于辨识的纵向力估计模型。进行底盘测功机道路模拟试验并采集数据。模型输入与噪声相关时,子空间 N4SID (nu-merical algorithm for subspace identification)辨识算法是有偏的,针对这一问题,研究了一种改进闭环子空间辨识算法。结果表明:对比子空间 N4SID 辨识算法,改进闭环子空间辨识算法辨识出的模型具有更好的抗干扰性,纵向力估计精度更高,实时跟踪效果更好,满足基于数据驱动的驱动力模型预测控制的需求。

  6. A Study on the In-wheel Motor Control Strategy for Four-wheel Independent Drive Electric Vehicles%四轮独立驱动电动汽车轮毂电机控制策略的研究

    Institute of Scientific and Technical Information of China (English)

    黄启然; 郑玲; 李以农; 卢少波

    2014-01-01

    为降低轮毂电机转矩脉动对电动汽车平顺性的影响,提出了开关磁阻电机的控制策略。建立了电机的非线性模型,对电机进行了最优角度控制。针对电机转矩脉动问题,首先在直接转矩分配控制基础上,采用模糊算法对传统PID控制器的参数进行在线整定,其次提出将快速终端滑模控制算法与直接转矩分配相结合的控制策略。仿真结果表明,模糊算法的引入提高了系统的稳定性;而快速终端滑模控制算法不仅提高了系统抗干扰的能力,而且降低了电机的转矩脉动。%For reducing the effects of torque ripple in wheel hub motor on the ride comfort of electric vehi-cles, a control strategy for switched reluctance motor ( SRM) is proposed. A nonlinear model for SRM is set up and the optimum switching angle control is exerted on SRM. As for the issue of motor torque fluctuation, firstly the fuzzy algorithm is used to conduct online tuning on the parameters of conventional PID controller based on direct torque distribution control;then a control strategy combining fast terminal sliding mode algorithm with direct torque alloca-tion is put forward. The results of simulation show that the introduction of fuzzy algorithm enhances the stability of system while the use of fast terminal sliding mode algorithm not only raises the disturbance resistance of system, but also reduces the torque ripple of motor.

  7. A Research on the ABS Test Method for Four-Wheel-Drive Vehicle Equipped with Viscous Coupler%装备黏性联轴器四驱车辆的ABS试验方法研究

    Institute of Scientific and Technical Information of China (English)

    谢东明; 苑林; 郭勇; 梁荣亮; 高吉强; 李卫军; 齐辉平

    2012-01-01

    In the antilock braking system ( ABS) test for four-wheel-drive vehicle equipped with viscous coupler, when traditional disposal ( making failure of one axle's braking) is adopted, the adhesion coefficient obtained of low-adhesion lane far exceeds the real value. The reason is revealed through the in-depth analyses in this paper that when one axle's braking fails, there is a significant difference between the rotation speeds of front and rear axles caused by the variation of tires slip ratio, leading to the occurrence of hump phenomena in viscous coupler, then the front and rear axles become quasi-rigid connected and all the wheels involve in braking. Therefore it is suggested that in the ABS test for four-wheel-drive vehicle equipped with viscous coupler, the input shaft of viscous coupler should be dismounted for making only one axle involved in braking, so that a right adhesion coefficient can be obtained.%装备黏性联轴器的四驱车辆在进行防抱死制动系统的试验中,按照传统的使单轴制动失效的办法获得的低附路面附着系数远高于试验路面实际的附着系数.文中通过分析揭示了其原因是:单轴制动失效时前、后轴轮胎滑移率变化造成转速差过大而产生驼峰现象,前、后轴形成准刚性连接而共同参与制动.因此,装备黏性联轴器的四驱车辆在进行ABS路面附着系数试验时应将黏性联轴器输入轴拆除,使之仅有单轴参与制动,才能获得正确的路面附着系数.

  8. Co-simulation Research of Dual-steering Control for Multi-in-wheel Motors Drive Armored Vehicle%电驱动装甲车辆双重转向控制联合仿真

    Institute of Scientific and Technical Information of China (English)

    苏建强; 马晓军; 项宇; 阳贵兵

    2014-01-01

    To improve the steering agility and off-road mobility of multi-in-wheel motors drive armored wheeled vehicle,the dual-steering control is adopted corresponding to the tracked vehicle steering way. The target of control system is the vehicle yaw rate,and active disturbance rejection controller is designed. Yaw moment torque is produced by adjusting the both sides of the in-wheel motor torque output to achieve the target of reference yaw rate. The vehicle kinetics model is built in the Adams,and the co-simulation model is designed base on the Adams and Matlab. At last co-simulation is carried out. The results of simulation demonstrate that the dual-steering control increased the vehicle outboard power output and decreased the steering radius. The method could improve the steering performance.%为了提高轮毂电机驱动装甲车辆转向的灵活性及越野机动性能,借鉴履带车辆滑移转向思想,采用双重转向控制策略。以车辆的横摆角速度为控制目标,设计了自抗扰控制器,通过调整两侧轮毂电机转矩输出产生直接横摆力矩,进而调节车辆横摆角速度,实现装甲车辆双重转向。在Adams中建立车辆动力学模型的基础上,构建Adams与Matlab环境中的联合仿真模型,并进行了联合仿真,结果表明,基于直接横摆力矩控制的双重转向增大了外侧动力输出,减小了车辆在中低速转向时转向半径,提高了车辆的转向性能。

  9. Temperature Field Accurate Modeling and Cooling Performance Evaluation of Direct-Drive Outer-Rotor Air-Cooling In-Wheel Motor

    Directory of Open Access Journals (Sweden)

    Feng Chai

    2016-10-01

    Full Text Available High power density outer-rotor motors commonly use water or oil cooling. A reasonable thermal design for outer-rotor air-cooling motors can effectively enhance the power density without the fluid circulating device. Research on the heat dissipation mechanism of an outer-rotor air-cooling motor can provide guidelines for the selection of the suitable cooling mode and the design of the cooling structure. This study investigates the temperature field of the motor through computational fluid dynamics (CFD and presents a method to overcome the difficulties in building an accurate temperature field model. The proposed method mainly includes two aspects: a new method for calculating the equivalent thermal conductivity (ETC of the air-gap in the laminar state and an equivalent treatment to the thermal circuit that comprises a hub, shaft, and bearings. Using an outer-rotor air-cooling in-wheel motor as an example, the temperature field of this motor is calculated numerically using the proposed method; the results are experimentally verified. The heat transfer rate (HTR of each cooling path is obtained using the numerical results and analytic formulas. The influences of the structural parameters on temperature increases and the HTR of each cooling path are analyzed. Thereafter, the overload capability of the motor is analyzed in various overload conditions.

  10. Piezoelectric Wheel System

    Science.gov (United States)

    Juang, Puu-An

    2007-10-01

    A piezoelectric wheel system is proposed for used as a microstepping displacement device including a carrier and two displacement members, which are separately pivoted on the carrier. Each displacement member includes two wheels, and which can not rotate. In addition, each wheel includes a wheel sheet and a piezoelectric element embedded on its surface. When the piezoelectricity element generates and transmits power to the wheel sheet, the wheel induces vibration and deformation. Therefore, owing to the wheel sheets and the touched ground involving their relative motion, the displacement device can be moved or can be oriented its motion direction. The wheel system involves direct movement, and has no rotor requirement. In this research, a three-dimensional (3D) mechanical element with an extra electrical degree of freedom is employed to simulate the dynamic vibration modes of the linear piezoelectric, mechanical, and piezoelectric-mechanical behaviours of the piezoelectric wheel.

  11. Control Electronics For Reaction Wheel

    Science.gov (United States)

    Chamberlin, Keith

    1995-01-01

    Bidirectional operation achieved with single-polarity main power supply. Control circuitry generates pulse-width-modulated 800-Hz waveforms to drive two-phase ac motor and reaction wheel. Operates partly in response to digital magnitude-and-direction torque command generated by external control subsystem and partly in response to tachometric feedback in form of two once-per-revolution sinusoids with amplitudes proportional to speed. Operation in either of two modes called "normal" and "safehold." In normal mode, drive pulses timed so that, on average over one or few cycles, motor applies commanded torque. In safehold mode, pulses timed to keep motor running at set speed in one direction.

  12. 四轮驱动电动汽车永磁无刷轮毂电机转矩分配%Torque distribution algorithm for a permanent brushless DC hub motor for four-wheel drive electric vehicles

    Institute of Scientific and Technical Information of China (English)

    卢东斌; 欧阳明高; 谷靖; 李建秋

    2012-01-01

    四轮驱动轮毂电机电动汽车采用4个永磁无刷轮毂电机驱动,根据轮毂电机的反电势接近正弦波的特点,采用磁场定向控制方法可以实现最大转矩电流控制。该文在永磁同步电机磁场定向控制效率模型的基础上,提出了相同转速转矩下的多永磁同步电机系统效率模型,根据此模型证明了多永磁同步电机系统相同转速下转矩平均分配可使电机系统效率达到最优。将此结论应用到四轮驱动电动汽车轮毂电机转矩分配研究中,通过仿真和实车测试进行验证。仿真和试验结果证明,平均分配永磁无刷轮毂电机转矩可使整车效率最优。%Four in-wheel motors drive electric vehicles are driven by four brushless DC hub motors. Since the back electromotive force (emf) waveform of a permanent brushless DC hub motor is usually nearly sinusoidal, the maximum torque per ampere control can be found using field oriented control (FOC). An efficiency model for a permanent magnet synchronous motor (PMSM) was used in an efficiency model of multi-PMSMs with the same speed and torque. The optimal efficiency can be achieved based on the average torque distribution assuming all the same speed PMSMs. This conclusion can be applied to the torque distribution of brushless DC hub motors for four-wheel drive electric vehicles. Simulation and experimental results show that the average torque allocation to the four hub motors of the electric vehicle gives the best efficiency.

  13. Development of the FASTER Wheeled Bevameter

    Science.gov (United States)

    Richter, L.; Eder, V.; Hoheneder, W.; Imhof, B.; Lewinger, W.; Ransom, S.; Saaj, C.; Weclewski, P.; Waclavicek, R.,

    2014-04-01

    This paper describes the development of a Wheeled Bevameter (WB) within the FASTER project (Forward Acquisition of Soil and Terrain Data for Exploration Rovers), funded by the European Union's FP7 programme. In FASTER, novel and innovative concepts for in situ forward sensing of soil properties and terrain conditions in the planned path of a planetary rover are developed. Terrain strength measurements for assessment of the mobility of crosscountry vehicles have decades of heritage on Earth, but typically trafficability of terrains is only gauged by human operators ahead of vehicle operations rather than in-line by probes deployed from the vehicle itself, as is intended for FASTER. For FASTER, a Wheeled Bevameter (WB) has been selected as the terrain sensing instrument for the vehicle. Wheeled Bevameters are suitable for terrain measurements while driving but traditionally have mostly been employed on terrestrial vehicles to evaluate particular wheel designs. The WB as conceived in FASTER uses a dedicated, passive-rolling test wheel (‚test wheel') placed on the terrain as the loading device to enable to determine bearing strength, compressive strength and shear strength of the terrain immediately ahead of the vehicle, as well as rover-terrain interaction parameters used in semi-empirical vehicle-terrain traction models. The WB includes a placement mechanism for the test wheel. The test wheel would remain lowered onto the ground during nominal rover motion, including when climbing and descending slopes. During normal operations, the placement mechanism assumes the function of a passive suspension of the wheel, allowing it to follow the terrain contour. Quantities measured with the WB are: test wheel sinkage (through a laser sensor), test wheel vertical load, test wheel horizontal reaction force, and test wheel rotation rate. Measurements are performed while the rover is in motion. Measured test wheel rotation rate (with appropriate corrections for slight skid) can

  14. WC5E型铰接式四驱矿用自卸车传动轴的设计%Design of transmission shafts of WC5E articulated mine dump truck with four-wheel driving

    Institute of Scientific and Technical Information of China (English)

    王庆祥; 郭培燕; 王素慧

    2012-01-01

    针对WC5E型铰接式四驱矿用自卸车的结构特点和传动轴布置形式,通过分析各传动轴的工作状态和运动轨迹,确定了传动轴的长度、伸缩量和断面尺寸等主要性能参数,并根据所传递扭矩和转速对其进行了强度计算和校核,最终设计出满足整车使用要求的传动轴,为此类车辆传动系统的设计提供了方法和依据。%According to the structural features of WC5E articulated mine dump truck with four-wheel driving and the layout of its transmission shafts, after analyzing the operation status and motion track of each transmission shaft, the paper determined the main parameters of the transmission shafts such as the length, shrinkage and cross dimension etc. In addition, the strength calculation and checking of the transmission shafts were conducted according to the transmitted torque and rotary speed. Finally, the transmission shafts meeting the employment requirements of the dump truck were designed, which offered methods and references for design of the transmission system in the truck.

  15. Regenerative braking control technology for wheel-side electric driving system%轮边电力驱动系统再生制动控制技术研究

    Institute of Scientific and Technical Information of China (English)

    卞永明; 兰皓; 蒋佳; 李生博; 吴昊; 金晓林

    2011-01-01

    轮边电力驱动系统中的再生制动系统主要涉及制动能量分配控制技术和再生制动能量回收控制技术.轮边电力驱动工程机械采用双向DC/DC变换器,结合电压电流双闭环控制实现超级电容的储能,从而控制再生制动能量的回收.通过MATLAB建模仿真表明,在满足安全制动的前提下,能够实现最大化的能量回收.%The regenerative braking system of wheel-side electric driving system mainly comprises the control technologies for braking energy distribution and regenerative energy recovery. To control the regenerative braking energy recovery, a bi-directional DC/DC converter, together with a double closedloop voltage-current control, is applied for super-capacitor energy storage of relevant construction machinery. By employing MatlabTM modeling and simulation, it is indicated that the energy recovery maximization could be realized to meet the demand on braking safety.

  16. Power Matching Computation and Simulation Analysis of Multi-Wheel Drive Armored Vehicle%多轮驱动履带车辆功率匹配计算与仿真分析*

    Institute of Scientific and Technical Information of China (English)

    曾庆含; 杨波; 刘春光; 杨宗民

    2013-01-01

    In order to overcome the difficulty of motor integration in electric drive tracked vehicle under traditional scheme,a new multi-wheel drive EV design scheme which can reduce requirement of motor power is developed. First,performance parameters matching compute of the drive motor and mechanical transmission device is put forward according to the design parameters and performance index of this tracked vehicle. Then,the drive motor system was built based on control system analysis software Matlab/Simulink and the tracked vehicle running gear on multi-body dynamics analysis software RecurDyn/Track-HM. And ,the collaborative simulation model based on interface technology of these two software was also built. The collaborative simulation results about the dynamic characteristics showed that this scheme can achieve the expected target ,the computing method and matching parameters are right,which lays the foundation for further research.%  传统电传动设计方案下同时满足车辆大扭矩和宽调速范围的电机体积、重量大,难以集成在车辆有限空间内,针对这一难题,提出了一种新型多轮驱动电传动车辆设计方案。结合该方案,以原车性能指标为依据,进行了电机驱动系统的性能匹配计算,建立了基于Matlab/Simulink的驱动电机模块和基于RecurDyn/Track-HM车辆动力学仿真模块,并利用接口技术构建了机电一体联合仿真模型,而后通过车辆动力性能的仿真,对设计方案及功率匹配结果进行验证。仿真结果表明,匹配算法正确,所选参数合理,设计方案基本可行,为进一步研究奠定了基础。

  17. Hybrid Control Design for a Wheeled Mobile Robot

    DEFF Research Database (Denmark)

    Bak, Thomas; Bendtsen, Jan Dimon; Ravn, Anders Peter

    We present a hybrid systems solution to the problem of trajectory tracking for a four-wheel steered four-wheel driven mobile robot. The robot is modelled as a non-holonomic dynamic system subject to pure rolling, no-slip constraints. Under normal driving conditions, a nonlinear trajectory tracking...

  18. Wheel traffic effect on air-filled porosity and air permeability in a soil catena across the wheel rut

    DEFF Research Database (Denmark)

    Berisso, Feto Esimo; Schjønning, Per; Lamandé, Mathieu

    experiment was conducted on a clay loam soil at Suberg, Switzerland, in 2010. Four repeated wheeling were performed by driving a forage harvester (wheel load of 6100 kg and a tyre width of 0.8 m) forward and rearward in the same track. We sampled 100 cm3 intact cores at 10, 30 and 50 cm depth in a soil...

  19. Effect of Wheel Load on Wheel Vibration and Sound Radiation

    Institute of Scientific and Technical Information of China (English)

    HAN Jian; WANG Ruiqian; WANG Di; GUAN Qinghua; ZHANG Yumei; XIAO Xinbiao; JIN Xuesong

    2015-01-01

    The current researches of wheel vibration and sound radiation mainly focus on the low noise damped wheel. Compared with the traditional research, the relationship between the sound and wheel/rail contact is difficulty and worth studying. However, there are few studies on the effect of wheel load on wheel vibration and sound radiation. In this paper, laboratory test carried out in a semi-anechoic room investigates the effect of wheel load on wheel natural frequencies, damping ratios, wheel vibration and its sound radiation. The laboratory test results show that the vibration of the wheel and total sound radiation decrease significantly with the increase of the wheel load from 0 t to 1 t. The sound energy level of the wheel decreases by 3.7 dB. When the wheel load exceeds 1 t, the attenuation trend of the vibration and sound radiation of the wheel becomes slow. And the increase of the wheel load causes the growth of the wheel natural frequencies and the mode damping ratios. Based on the finite element method (FEM) and boundary element method (BEM), a rolling noise prediction model is developed to calculate the influence of wheel load on the wheel vibration and sound radiation. In the calculation, the used wheel/rail excitation is the measured wheel/rail roughness. The calculated results show that the sound power level of the wheel decreases by about 0.4 dB when the wheel load increases by 0.5 t. The sound radiation of the wheel decreases slowly with wheel load increase, and this conclusion is verified by the field test. This research systematically studies the effect of wheel load on wheel vibration and sound radiation, gives the relationship between the sound and wheel/rail contact and analyzes the reasons, therefore, it provides a reference for further research.

  20. Steered wheel for the support and/or steering of a vehicle, particularly hovercraft

    Energy Technology Data Exchange (ETDEWEB)

    Duell, H.J.; Kirchner, G.

    1977-04-07

    The invention concerns a steered wheel for the support or steering of a hovercraft, whose wheel suspension is provided with an eccentric journal for automatic setting in the direction of travel. So that the vehicle will not leave its track during changes of direction when the wheel is turned around the eccentric axis, according to the invention the wheel is supported on movable bearings at the journal in the direction of the driving axle.

  1. Aerodynamic analysis of an isolated vehicle wheel

    Science.gov (United States)

    Leśniewicz, P.; Kulak, M.; Karczewski, M.

    2014-08-01

    Increasing fuel prices force the manufacturers to look into all aspects of car aerodynamics including wheels, tyres and rims in order to minimize their drag. By diminishing the aerodynamic drag of vehicle the fuel consumption will decrease, while driving safety and comfort will improve. In order to properly illustrate the impact of a rotating wheel aerodynamics on the car body, precise analysis of an isolated wheel should be performed beforehand. In order to represent wheel rotation in contact with the ground, presented CFD simulations included Moving Wall boundary as well as Multiple Reference Frame should be performed. Sliding mesh approach is favoured but too costly at the moment. Global and local flow quantities obtained during simulations were compared to an experiment in order to assess the validity of the numerical model. Results of investigation illustrates dependency between type of simulation and coefficients (drag and lift). MRF approach proved to be a better solution giving result closer to experiment. Investigation of the model with contact area between the wheel and the ground helps to illustrate the impact of rotating wheel aerodynamics on the car body.

  2. Model laws for water wheels and their application to overshot water wheels; Modellgesetze fuer Wasserraeder und ihre Anwendung auf das oberschlaechtige Wasserrad

    Energy Technology Data Exchange (ETDEWEB)

    Nuernbergk, Dirk M.

    2009-07-01

    For several years, water wheels as a technological drive increasingly gain attention. Water wheels with goitre drain and overshot water wheels have an efficiency of up to 80 %. The question of how this can be exploited on a real location rises. Furthermore, the question of conversion rules rises, if one calculates back a model wheel to a particular location. The required model laws are be derived again in the contribution under consideration. The application of these model laws on the overshot water wheel are explained.

  3. Reimagining the Color Wheel

    Science.gov (United States)

    Snyder, Jennifer

    2011-01-01

    Color wheels are a traditional project for many teachers. The author has used them in art appreciation classes for many years, but one problem she found when her pre-service art education students created colored wheels was that they were boring: simple circles, with pie-shaped pieces, which students either painted or colored in. This article…

  4. Design and engineering structure analysis on paddy-field chassis steering drive axle with standard all-wheel-drive%标准四驱水田自走底盘转向驱动桥设计与工程结构分析

    Institute of Scientific and Technical Information of China (English)

    刘宏新; 郑利双; 徐高伟; 王晨

    2015-01-01

    In the main grain crop production in China, comprehensive mechanization level for paddy field is the lowest. At the same time, there exists the“bottleneck”problem of“bottleneck”problem such as rice planting mechanization. In the case of transplanter, although we have grasped the core technology of key components, overall machinery can not be popularized and applied due to lack of the support of cost-effective chassis. At present, in Chinese market, most of chassis are imported from Japan and South Korea, which widely use hydraulic transmission and variable speed technology. Because paddy planting operation has the characteristics of stable load and constant speed, using hydraulic transmission and continuous variable device causes low efficiency and has no much practical significance, and meanwhile, the demand for the power increases from 9 to 13 and even 15 kw. Northeast Agricultural University has designed a standard all-wheel drive light paddy self-propelled chassis with diesel-power and mechanical transmission for this situation, whose most prominent shape feature is that four wheels have same size and the front axle is different from any existing paddy field chassis structure. The chassis has the advantages of high transmission efficiency, large torque reserve, anti-sink capacity, dynamic stabilization, and good performance of crossing the earth bank between the paddy fields. As a transmission part, steering drive axle not only is a carrier installed, but also needs to bear the weight of chassis and the effect of impulsive load, and have the function of deflection wheel, and hence its structure is more complex than the traditional shell. The operating environment of paddy field chassis is harsher than general vehicle, which has stricter requirement of sludge, subsidence, bank and over load on axle. So, engineering analysis of structural design process is particularly important, however, conventional theoretical analysis and calculation method can not

  5. The Reaction Wheel Pendulum

    CERN Document Server

    Block, Daniel J; Spong, Mark W

    2007-01-01

    This monograph describes the Reaction Wheel Pendulum, the newest inverted-pendulum-like device for control education and research. We discuss the history and background of the reaction wheel pendulum and other similar experimental devices. We develop mathematical models of the reaction wheel pendulum in depth, including linear and nonlinear models, and models of the sensors and actuators that are used for feedback control. We treat various aspects of the control problem, from linear control of themotor, to stabilization of the pendulum about an equilibrium configuration using linear control, t

  6. TO SUBSTANTIATION OF COMBINE WHEELED CHASSIS FOR BEET HARVESTING EQUIPMENT

    Directory of Open Access Journals (Sweden)

    G. A. Tajanowskij

    2016-01-01

    Full Text Available The paper considers a current scientific and technical problem pertaining to creation of multi-bridge wheeled chassis for highly efficient modular sugar beet harvesters of large cargo capacity and, in particular, to selection of main parameters of chassis and wheeled drive. Such machines are designed for operation under complicated soil and climatic conditions during sugar beet harvesting. Methodological rules and regulations have been developed for solution of problems pertaining to scientifically sunstantiated selection of a manufactured or developed wheeled chassis model, building-block parameters of a working device and a chassis, rational control algorithm of the unit running system while using a specified (domestic or foreign semi-mounted equipment for beet harvesting. While solving the problem theoretical provisions for wheeled vehicles regarding specific features of a wheeled chassis for modular sugar beet harvesters with extensive mechanical or hydrostatic wheel drive of a multi-bridge propulsion system have been developed in the paper. Calculated and theoretical expressions for determination of main parameters for a wheeled chassis have been obtained and they include physical quantities of operational conditions that explicitly determine its working process. Such approach has made it possible to realize the obtained expressions as a software application which is suitable for analysis of main parameters in respect of the investigated harvester chassis and rational parameters of a branch wheel drive and also for a complete set of tires in the case when a sugar beet harvester is designed on the basis of wheeled chassis according to the selected scheme. Investigations have theoretical significance and represent practical interest for development spesialists of new modular multi-bridge sugar beet harvesters.

  7. [Two-wheeled cart

    OpenAIRE

    2003-01-01

    205 x 139 mm. A view showing a two-wheeled wooden cart being pulled by two bovine quadrupeds. A man is sitting in the cart and a European man is standing to the side watching. Photograph taken circa 1900.

  8. Hybrid Control Design for a Wheeled Mobile Robot

    DEFF Research Database (Denmark)

    Bak, Thomas; Bendtsen, Jan Dimon; Ravn, Anders Peter

    2003-01-01

    We present a hybrid systems solution to the problem of trajectory tracking for a four-wheel steered four-wheel driven mobile robot. The robot is modelled as a non-holonomic dynamic system subject to pure rolling, no-slip constraints. Under normal driving conditions, a nonlinear trajectory trackin....... The stability of the hybrid control scheme is finally analyzed using Lyapunov-like arguments....

  9. Wheeled hopping robot

    Science.gov (United States)

    Fischer, Gary J [Albuquerque, NM

    2010-08-17

    The present invention provides robotic vehicles having wheeled and hopping mobilities that are capable of traversing (e.g. by hopping over) obstacles that are large in size relative to the robot and, are capable of operation in unpredictable terrain over long range. The present invention further provides combustion powered linear actuators, which can include latching mechanisms to facilitate pressurized fueling of the actuators, as can be used to provide wheeled vehicles with a hopping mobility.

  10. Small Satellite Reaction Wheel Optimization

    OpenAIRE

    Michaelis, Ted

    1990-01-01

    The very "smallness" of small satellites mandates mass minimization. This paper addresses minimization of overall reaction wheel mass, including the incremental mass of the power subsystem needed to support the reaction wheel. The results are applicable to a wide range of wheel sizes and are suitable for optimization at the configuration level. For an average momentum and torque operating point, the minimization process yields wheel radius and angular velocity, as well as, the masses associat...

  11. Biologically Inspired Modular Neural Control for a Leg-Wheel Hybrid Robot

    DEFF Research Database (Denmark)

    Manoonpong, Poramate; Wörgötter, Florentin; Laksanacharoen, Pudit

    2014-01-01

    processing and state memorization. Its outputs drive two front wheels while the rear wheel is controlled through a velocity regulating network (VRN) module. In parallel, a neural oscillator network module serves as a central pattern generator (CPG) controls leg movements for sidestepping. Stepping directions...

  12. Indices and Computational Strategy for Unmanned Ground Wheeled Vehicle Mobility Estimation and Enhancement

    Science.gov (United States)

    2013-08-01

    proper tire to terrain interactions. The current work applies this strategic approach to both multi-wheel UGVs with mechanical/ mechatronic driveline...Coefficient”, IEEE/ASME Transactions of Mechatronics , Vol. 9, N 2, pp. 454-458. [37] Larin, V.V., 2010, “Theory of Motion of All-Wheel Drive

  13. Forces on wheels and fuel consumption in cars

    CERN Document Server

    Güémez, J

    2014-01-01

    Motivated by real classroom discussions, we analyse the forces acting on moving vehicles, specifically friction forces on the wheels. In usual cars, with front-wheel drive, when the car accelerates these forces are in the forward direction in the front wheels, but they are in the opposite direction in the rear wheels. The situation may be intriguing for students, but it may also be helpful and stimulating to clarify the role of friction forces on rolling objects. In this article we also study thermodynamical aspects of an accelerating car, relating the distance traveled with the amount of fuel consumed. The fuel consumption is explicitly shown to be Galilean invariant and we identify the Gibbs free energy as the relevant quantity that enters in the thermodynamical description of the accelerating car. The more realistic case of the car's motion taking into account the dragging forces is also discussed.

  14. Rotating Wheel Wake

    Science.gov (United States)

    Lombard, Jean-Eloi; Xu, Hui; Moxey, Dave; Sherwin, Spencer

    2016-11-01

    For open wheel race-cars, such as Formula One, or IndyCar, the wheels are responsible for 40 % of the total drag. For road cars, drag associated to the wheels and under-carriage can represent 20 - 60 % of total drag at highway cruise speeds. Experimental observations have reported two, three or more pairs of counter rotating vortices, the relative strength of which still remains an open question. The near wake of an unsteady rotating wheel. The numerical investigation by means of direct numerical simulation at ReD =400-1000 is presented here to further the understanding of bifurcations the flow undergoes as the Reynolds number is increased. Direct numerical simulation is performed using Nektar++, the results of which are compared to those of Pirozzoli et al. (2012). Both proper orthogonal decomposition and dynamic mode decomposition, as well as spectral analysis are leveraged to gain unprecedented insight into the bifurcations and subsequent topological differences of the wake as the Reynolds number is increased.

  15. 3-D Color Wheels

    Science.gov (United States)

    DuBois, Ann

    2010-01-01

    The blending of information from an academic class with projects from art class can do nothing but strengthen the learning power of the student. Creating three-dimensional color wheels provides the perfect opportunity to combine basic geometry knowledge with color theory. In this article, the author describes how her seventh-grade painting…

  16. 3-D Color Wheels

    Science.gov (United States)

    DuBois, Ann

    2010-01-01

    The blending of information from an academic class with projects from art class can do nothing but strengthen the learning power of the student. Creating three-dimensional color wheels provides the perfect opportunity to combine basic geometry knowledge with color theory. In this article, the author describes how her seventh-grade painting…

  17. Color Wheel Windows

    Science.gov (United States)

    Leonard, Stephanie

    2012-01-01

    In this article, the author describes a painting and drawing lesson which was inspired by the beautiful circular windows found in cathedrals and churches (also known as "rose windows"). This two-week lesson would reinforce both the concept of symmetry and students' understanding of the color wheel. (Contains 1 online resource.)

  18. Drive system failure control for distributed drive electric vehicles

    Science.gov (United States)

    Liu, Tao; Tang, Yuan; Wang, Jianfeng; Li, Yaou; Yang, Na; Liu, Yiqun

    2017-09-01

    Aiming at the failure problem of distributed electric drive vehicle, the conventional control strategy of drive system failure is designed according to the characteristics of each wheel torque independent control and the redundant configuration of the power unit. On this basis, combined with the traditional body stability control technology, the direct yaw moment control method is used. The simulation results show that the conventional control method designed of the drive system failure can effectively improve the driving condition of the vehicle. The driving stability of the vehicle is further improved after the direct yaw torque control is applied.

  19. Construction of a Special Mobile Robot that Uses a Special Travelling Wheel

    Directory of Open Access Journals (Sweden)

    Brabec Pavel

    2016-01-01

    Full Text Available This paper deals with the engineering design of a solution of a mobile robot that uses a special travelling wheel for transmission of motive power onto a surface. It further explains the principle of a vehicle travelling wheel that – according to an actual situation of the surface – changes the way of the wheel movement on the surface. The work content in our workplace is the engineering design of the solution of a mobile robot frame which uses a special travelling wheel pursuant to our patent to transfer the driving force onto the surface. This travelling wheel is able to transform and adapt to the driving conditions. Since it is an unmanned ground robot, not so common technical solutions can be used. Because it is also meant to be used in a rough terrain, the concept of four-wheel drive has been chosen and a four-wheel chassis has been designed to make it more simple. In terms of need of excellent handling and movement fluency, all four wheels will be directionally steered (4WS and will be placed as much in the frame corners as possible in order to have a space for 90° steer angle.

  20. The ubiquitous photonic wheel

    CERN Document Server

    Aiello, Andrea

    2016-01-01

    A circularly polarized electromagnetic plane wave carries an electric field that rotates clockwise or counterclockwise around the propagation direction of the wave. According to the handedness of this rotation, its \\emph{longitudinal} spin angular momentum density is either parallel or antiparallel to the propagation of light. However, there are also light waves that are not simply plane and carry an electric field that rotates around an axis perpendicular to the propagation direction, thus yielding \\emph{transverse} spin angular momentum density. Electric field configurations of this kind have been suggestively dubbed "photonic wheels". It has been recently shown that photonic wheels are commonplace in optics as they occur in electromagnetic fields confined by waveguides, in strongly focused beams, in plasmonic and evanescent waves. In this work we establish a general theory of electromagnetic waves {propagating along a well defined direction, which carry} transverse spin angular momentum density. We show th...

  1. Analysis of limit forces on the vehicle wheels using an algorithm of Dynamic Square Method

    Science.gov (United States)

    Brukalski, M.

    2016-09-01

    This article presents a method named as Dynamic Square Method (DSM) used for dynamic analysis of a vehicle equipped with a four wheel drive system. This method allows determination of maximum (limit) forces acting on the wheels. Here, the maximum longitudinal forces acting on the wheels are assumed and then used to predict whether they can be achieved by a specific dynamic motion or whether the actual friction forces under a given wheel is large enough to transfer lateral forces. For the analysis of DSM a four wheel vehicle model is used. On the basis of this characteristic it is possible to determine the maximum longitudinal force acting on the wheels of the given axle depending on the lateral acceleration of the vehicle. The results of this analysis may be useful in the development of a control algorithm used for example in active differentials.

  2. Design optimization on the front wheel orientation parameters of a vehicle

    Institute of Scientific and Technical Information of China (English)

    CHU Zhigang; DENG Zhaoxiang; HU Yumei; ZHU Ming

    2003-01-01

    A uniform optimization object function for front wheel orientation parameters of a vehicle is reported, which includes the tolerances of practical values and set values of front wheel orientation parameters under full load, and the changing value of each parameter with front wheel fluctuation to build a front suspension model for optimization analysis based on the multi-body dynamic (MD) theory. The original suspension is optimized with this model, and the variation law of each parameter with front wheel fluctuation is obtained. The results of a case study demonstrate that the front wheel orientation parameters of the optimized vehicle are reasonable under typical conditions and the variation of each parameter is in an ideal range with the wheel fluctuating within ±40 mm. In addition, the driving performance is improved greatly in the road test and practical use.

  3. Experiments with Electrodynamic Wheels

    Science.gov (United States)

    Gaul, Nathan; Corey, Daniel; Cordrey, Vincent; Majewski, Walerian

    2015-04-01

    Our experiments were involving inductive magnetic levitation. A Halbach array is a system in which a series of magnets is arranged in a manner such that the magnetic field is cancelled on one side of the array while strengthening the field on the other. We constructed two circular Halbach wheels, making the strong magnetic field on the outer rim of the ring. Such system is usually dubbed as an Electrodynamic Wheel (EDW). Rotating this wheel around a horizontal axis above a flat conducting surface should induce eddy currents in said surface through the variable magnetic flux. The eddy currents produce, in turn, their own magnetic fields which interact with the magnets of the EDW. We demonstrated that these interactions produce both drag and lift forces on the EDW which can theoretically be used for lift and propulsion of the EDW. The focus of our experiments is determining how to maximize the lift-to-drag ratio by the proper choice of the induction element. We will also describe our experiments with a rotating circular Halbach array having the strong magnetic field of about 1 T on the flat side of the ring, and acting as a hovercraft.

  4. A Multiple Data Fusion Approach to Wheel Slip Control for Decentralized Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Dejun Yin

    2017-04-01

    Full Text Available Currently, active safety control methods for cars, i.e., the antilock braking system (ABS, the traction control system (TCS, and electronic stability control (ESC, govern the wheel slip control based on the wheel slip ratio, which relies on the information from non-driven wheels. However, these methods are not applicable in the cases without non-driven wheels, e.g., a four-wheel decentralized electric vehicle. Therefore, this paper proposes a new wheel slip control approach based on a novel data fusion method to ensure good traction performance in any driving condition. Firstly, with the proposed data fusion algorithm, the acceleration estimator makes use of the data measured by the sensor installed near the vehicle center of mass (CM to calculate the reference acceleration of each wheel center. Then, the wheel slip is constrained by controlling the acceleration deviation between the actual wheel and the reference wheel center. By comparison with non-control and model following control (MFC cases in double lane change tests, the simulation results demonstrate that the proposed control method has significant anti-slip effectiveness and stabilizing control performance.

  5. Periodic roads and quantized wheels

    Science.gov (United States)

    de Campos Valadares, Eduardo

    2016-08-01

    We propose a simple approach to determine all possible wheels that can roll smoothly without slipping on a periodic roadbed, while maintaining the center of mass at a fixed height. We also address the inverse problem that of obtaining the roadbed profile compatible with a specific wheel and all other related "quantized wheels." The role of symmetry is highlighted, which might preclude the center of mass from remaining at a fixed height. A straightforward consequence of such geometric quantization is that the gravitational potential energy and the moment of inertia are discrete, suggesting a parallelism between macroscopic wheels and nano-systems, such as carbon nanotubes.

  6. Preliminary Design and Investigation of Integrated Compressor with Composite Material Wheel

    Science.gov (United States)

    Wang, Jifeng; Müller, Norbert

    2012-06-01

    An integrated water vapor compressor with composite material wheel is developed and strength analysis using FEM is presented. The design of wound composite material allows for integrating all rotating parts of the drive that may simply reduce to only the rotor of the electrical motor, since no drive shaft is required anymore. This design can reduce the number of parts and mass, which is convenient for engineers to maintain the compressor. The electrical motors are brushless DC motors operating through a frequency drive and apply a torque on the wheels through the materials bonded in the wheel shrouds. This system allows a large amount of compression to be produced in a multi-stage compression setup. To determine the stress and vibration characteristics of this integrated compressor, numerical analysis is carried out using FEM. The simulation result shows that the integrated compressor with composite material wheel can be used in a chiller system where water as a refrigerant.

  7. Hybrid Control Design for a Wheeled Mobile Robot

    DEFF Research Database (Denmark)

    Bak, Thomas; Bendtsen, Jan Dimon; Ravn, Anders Peter

    2003-01-01

    We present a hybrid systems solution to the problem of trajectory tracking for a four-wheel steered four-wheel driven mobile robot. The robot is modelled as a non-holonomic dynamic system subject to pure rolling, no-slip constraints. Under normal driving conditions, a nonlinear trajectory tracking...... feedback control law based on dynamic feedback linearization is sufficient to stabilize the system and ensure asymptotically stable tracking. Transitions to other modes are derived systematically from this model, whenever the configuration space of the controlled system has some fundamental singular points....... The stability of the hybrid control scheme is finally analyzed using Lyapunov-like arguments....

  8. A Feasability Study of the Wheel Electrostatic Spectrometer

    Science.gov (United States)

    Johansen, Michael Ryan; Phillips, James Ralph; Kelley, Joshua David; Mackey, Paul J.; Holbert, Eirik; Clements, Gregory R.; Calle, Carlos I.

    2014-01-01

    Mars rover missions rely on time-consuming, power-exhausting processes to analyze the Martian regolith. A low power electrostatic sensor in the wheels of a future Mars rover could be used to quickly determine when the rover is driving over a different type of regolith. The Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center developed the Wheel Electrostatic Spectrometer as a feasibility study to investigate this option. In this paper, we discuss recent advances in this technology to increase the repeatability of the tribocharging experiments, along with supporting data. In addition, we discuss the development of a static elimination tool optimized for Martian conditions.

  9. Reaction Wheel with Embedded MEMS IMU Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is to embed a MEMS IMU Sensor Chip into a reaction wheel to measure its spin rate as well as wheel attitude rate. We propose to use a reaction wheel...

  10. A Country on Wheels

    Institute of Scientific and Technical Information of China (English)

    小雨

    2007-01-01

    Cars are an important part of life in the United States. Most people feel that they are poor without cars. Though he is poor, he doesn't feel really poor when he has a car. Henry Ford was the man who first started making cars. Maybe, he didn't know how much the car was going to affect(影响) the United States. The cars made the United States a country on wheels(轮子). And they have helped to make the United States rich and modern.

  11. The outlook for wheeling

    Energy Technology Data Exchange (ETDEWEB)

    Zimmer, M.J.

    1990-04-01

    There is a continued national interest in decentralized power sources involving cogeneration and independent power production. But while these issues are debated in the halls of Congress, and the subject of generic rulemaking debate before the FERC, the real action is occurring elsewhere. Key momentum is building in the states ad individual electric utility systems requiring Federal Energy Regulatory Commission (FERC) and state commission review of discrete applications for case by case review. These reflect the pressure of competitive forces building within the industry from other electric utilities, power export marketeers, environmental and siting regulation, and from financial institutions. The underlying intent of PURPA is to encourage and provide incentives for the development of alternate energy sources to provide the efficient use of our nation's natural resources. Under PURPA the Commission can not direct an electric utility to provide transmission services. However, this power can only be exercised after a series of complex findings by the Commission through evidentiary hearings. In addition, PURPA amended other sections of the Federal Power Act to provide various rate incentives and exemptions for cogeneration and small power production facilities including the right for interconnection to the electric utility. The scope of such interconnection rights, and whether they might encompass broader transmission rights for QFs has yet to be tested. This paper describes wheeling rules prior to PURPA, the PURPA amendments governing wheeling; states' views; and the need for a review.

  12. Swirls and wheels

    Science.gov (United States)

    Maskit, B.

    1992-02-01

    There are several standard splittings of Kleinian groups using multiple combination theorems; these are the splitting of a function group into basic groups, the more general splitting of an analytically finite group into web groups, and the splitting given by Thurston of a Haken hyperbolic manifold. These splitting all use a finite set of combination theorems, where the order is, in some sense, irrelevant (the first two splittings mentioned above use only one such set; the Thurston splitting uses a finite sequence of these). A general theory of these finite sets of commuting splittings is built in the context of an arbitrary Kleinian group, and a descriptive language for these splittings is constructed. The point is decomposition rather than construction. One needs to be able to say that a given group could have been built up by using a commuting set of combination theorems, from certain subgroups, without specifying the subgroups. The description is given in terms of a system of swirls and wheels. Swirls are simple closed curves with certain additional properties, and wheels are generalized simple closed curves; these will be described. A system of these is a G-invariant collection, where no element of the system crosses any other element of the system, although they may touch at carefully controlled points.

  13. Design And Development Of Three Wheeled Campus Vehicle

    Directory of Open Access Journals (Sweden)

    Sharad Patel

    2015-08-01

    Full Text Available In todays world infrastructure of College and Industries are becoming large so if one has to travel or visit from one place to another he has to walk long distance and sometimes it becomes very hasty and inconvenient. Sometimes after too many traveling in campus it causes strain and pain in body. So to travel these distances two-wheeled or three wheeled electric scooter like Segway PT Irrway were introduced. But these scooters are very costly such as they starts from amp8377 50000. Another problem with those vehicle is that they are difficult to handle when we drive first time. So in alternate to this product we developed whole newly designed product and this is Reliable Ecofriendly Compact vehicle for campus. Its utilities are college campus Airports Industries Recreational Parks Sanctuaries Museums Palaces Villas etc. So Our research is on design and development of three-wheel campus vehicle and also its multipurpose utility among the society.

  14. Squeaky Wheel Optimization

    CERN Document Server

    Clements, D P; 10.1613/jair.561

    2011-01-01

    We describe a general approach to optimization which we term `Squeaky Wheel' Optimization (SWO). In SWO, a greedy algorithm is used to construct a solution which is then analyzed to find the trouble spots, i.e., those elements, that, if improved, are likely to improve the objective function score. The results of the analysis are used to generate new priorities that determine the order in which the greedy algorithm constructs the next solution. This Construct/Analyze/Prioritize cycle continues until some limit is reached, or an acceptable solution is found. SWO can be viewed as operating on two search spaces: solutions and prioritizations. Successive solutions are only indirectly related, via the re-prioritization that results from analyzing the prior solution. Similarly, successive prioritizations are generated by constructing and analyzing solutions. This `coupled search' has some interesting properties, which we discuss. We report encouraging experimental results on two domains, scheduling problems that ari...

  15. Coordinated control of slip ratio for wheeled mobile robots climbing loose sloped terrain.

    Science.gov (United States)

    Li, Zhengcai; Wang, Yang

    2014-01-01

    A challenging problem faced by wheeled mobile robots (WMRs) such as planetary rovers traversing loose sloped terrain is the inevitable longitudinal slip suffered by the wheels, which often leads to their deviation from the predetermined trajectory, reduced drive efficiency, and possible failures. This study investigates this problem using terramechanics analysis of the wheel-soil interaction. First, a slope-based wheel-soil interaction terramechanics model is built, and an online slip coordinated algorithm is designed based on the goal of optimal drive efficiency. An equation of state is established using the coordinated slip as the desired input and the actual slip as a state variable. To improve the robustness and adaptability of the control system, an adaptive neural network is designed. Analytical results and those of a simulation using Vortex demonstrate the significantly improved mobile performance of the WMR using the proposed control system.

  16. Characterizing Wheel-Soil Interaction Loads Using Meshfree Finite Element Methods: A Sensitivity Analysis for Design Trade Studies

    Science.gov (United States)

    Contreras, Michael T.; Trease, Brian P.; Bojanowski, Cezary; Kulakx, Ronald F.

    2013-01-01

    A wheel experiencing sinkage and slippage events poses a high risk to planetary rover missions as evidenced by the mobility challenges endured by the Mars Exploration Rover (MER) project. Current wheel design practice utilizes loads derived from a series of events in the life cycle of the rover which do not include (1) failure metrics related to wheel sinkage and slippage and (2) performance trade-offs based on grouser placement/orientation. Wheel designs are rigorously tested experimentally through a variety of drive scenarios and simulated soil environments; however, a robust simulation capability is still in development due to myriad of complex interaction phenomena that contribute to wheel sinkage and slippage conditions such as soil composition, large deformation soil behavior, wheel geometry, nonlinear contact forces, terrain irregularity, etc. For the purposes of modeling wheel sinkage and slippage at an engineering scale, meshfree nite element approaches enable simulations that capture su cient detail of wheel-soil interaction while remaining computationally feasible. This study implements the JPL wheel-soil benchmark problem in the commercial code environment utilizing the large deformation modeling capability of Smooth Particle Hydrodynamics (SPH) meshfree methods. The nominal, benchmark wheel-soil interaction model that produces numerically stable and physically realistic results is presented and simulations are shown for both wheel traverse and wheel sinkage cases. A sensitivity analysis developing the capability and framework for future ight applications is conducted to illustrate the importance of perturbations to critical material properties and parameters. Implementation of the proposed soil-wheel interaction simulation capability and associated sensitivity framework has the potential to reduce experimentation cost and improve the early stage wheel design proce

  17. The big wheels of ATLAS

    CERN Multimedia

    2006-01-01

    The ATLAS cavern is filling up at an impressive rate. The installation of the first of the big wheels of the muon spectrometer, a thin gap chamber (TGC) wheel, was completed in September. The muon spectrometer will include four big moving wheels at each end, each measuring 25 metres in diameter. Of the eight wheels in total, six will be composed of thin gap chambers for the muon trigger system and the other two will consist of monitored drift tubes (MDTs) to measure the position of the muons (see Bulletin No. 13/2006). The installation of the 688 muon chambers in the barrel is progressing well, with three-quarters of them already installed between the coils of the toroid magnet.

  18. Wheels lining up for ATLAS

    CERN Multimedia

    2003-01-01

    On 30 October, the mechanics test assembly of the central barrel of the ATLAS tile hadronic calorimeter was completed in building 185. It is the second wheel for the Tilecal completely assembled this year.

  19. Wind wheel electric power generator

    Science.gov (United States)

    Kaufman, J. W. (Inventor)

    1980-01-01

    Wind wheel electric power generator apparatus includes a housing rotatably mounted upon a vertical support column. Primary and auxiliary funnel-type, venturi ducts are fixed onto the housing for capturing wind currents and conducting to a bladed wheel adapted to be operatively connected with the generator apparatus. Additional air flows are also conducted onto the bladed wheel; all of the air flows positively effecting rotation of the wheel in a cumulative manner. The auxiliary ducts are disposed at an acute angle with respect to the longitudinal axis of the housing, and this feature, together with the rotatability of the housing and the ducts, permits capture of wind currents within a variable directional range.

  20. Proposal to use vibration analysis steering components and car body to monitor, for example, the state of unbalance wheel

    Science.gov (United States)

    Janczur, R.

    2016-09-01

    The results of road tests of car VW Passat equipped with tires of size 195/65 R15, on the influence of the unbalancing front wheel on vibration of the parts of steering system, steering wheel and the body of the vehicle have been presented in this paper. Unbalances wheels made using weights of different masses, placed close to the outer edge of the steel rim and checked on the machine Hunter GSP 9700 for balancing wheels. The recorded waveforms vibration steering components and car body, at different constant driving speeds, subjected to spectral analysis to determine the possibility of isolating vibration caused by unbalanced wheel in various states and coming from good quality asphalt road surface. The results were discussed in terms of the possibility of identifying the state of unbalancing wheels and possible changes in radial stiffness of the tire vibration transmitted through the system driving wheel on the steering wheel. Vibration analysis steering components and car body, also in the longitudinal direction, including information from the CAN bus of the state of motion of the car, can be used to monitor the development of the state of unbalance wheel, tire damage or errors shape of brake discs or brake drums, causing pulsations braking forces.

  1. Computation of bicycle wheel power

    Institute of Scientific and Technical Information of China (English)

    尚寿亭; 吴龙; 薛立军; 徐吉杰

    2001-01-01

    Presents the model on the drag resistance to overcome discusses the equations used for calculation of spoked and solid wheel power and force, and gives a table of power output under a certain condition for comparison of two types of wheels, and suggests a scheme to estimate power on a specific track, and the speed and the time spent on a certain track are compared to illustrate the functions of parameters.

  2. Improved infrared-sensing running wheel systems with an effective exercise activity indicator.

    Science.gov (United States)

    Chen, Chi-Chun; Chang, Ming-Wen; Chang, Ching-Ping; Chang, Wen-Ying; Chang, Shin-Chieh; Lin, Mao-Tsun; Yang, Chin-Lung

    2015-01-01

    This paper describes an infrared-sensing running wheel (ISRW) system for the quantitative measurement of effective exercise activity in rats. The ISRW system provides superior exercise training compared with commercially available traditional animal running platforms. Four infrared (IR) light-emitting diode/detector pairs embedded around the rim of the wheel detect the rat's real-time position; the acrylic wheel has a diameter of 55 cm and a thickness of 15 cm, that is, it is larger and thicker than traditional exercise wheels, and it is equipped with a rubber track. The acrylic wheel hangs virtually frictionless, and a DC motor with an axially mounted rubber wheel, which has a diameter of 10 cm, drives the acrylic wheel from the outer edge. The system can automatically train rats to run persistently. The proposed system can determine effective exercise activity (EEA), with the IR sensors (which are connected to a conventional PC) recording the rat exercise behavior. A prototype of the system was verified by a hospital research group performing ischemic stroke experiments on rats by considering middle cerebral artery occlusion. The experimental data demonstrated that the proposed system provides greater neuroprotection in an animal stroke model compared with a conventional treadmill and a motorized running wheel for a given exercise intensity. The quantitative exercise effectiveness indicator showed a 92% correlation between an increase in the EEA and a decrease in the infarct volume. This indicator can be used as a noninvasive and objective reference in clinical animal exercise experiments.

  3. Delayed Bilateral Teleoperation of Wheeled Robots including a Command Metric

    OpenAIRE

    2015-01-01

    This paper proposes a control scheme applied to the delayed bilateral teleoperation of wheeled robots with force feedback, considering the performance of the operator`s command execution. In addition, the stability of the system is analyzed taking into account the dynamic model of the master as well as the remote mobile robot under asymmetric and time-varying delays of the communication channel. Besides, the performance of the teleoperation system, where a human operator drives a 3D simulator...

  4. Hydraulic energy storage for hydrostatic travel drives; Hydraulischer Energiespeicher fuer hydrostatische Fahrantriebe

    Energy Technology Data Exchange (ETDEWEB)

    Renz, Klaus [Bosch Rexroth AG, Elchingen (Germany). Anwendungstechnik Strassenbaumaschinen und Raupenfahrzeuge; Vogl, Karl-Heinz [Bosch Rexroth AG, Elchingen (Germany). Anwendungstechnik, Technischer Vertrieb; Brand, Michael [Bosch Rexroth AG, Elchingen (Germany). Anwendungsentwicklung Arbeitsmaschinen

    2010-09-15

    with their Hydraulic Fly Wheel (HFW) Bosch Rexroth has developed a new concept for hydrostatic travel drives which addresses the changed characteristics of the newest engine generation. As a consequence of the Tier 4 final regulations engines will soon exhibit more sluggish load assumption behaviour - the hydraulic fly wheel compensates for this and assists the hydrostatic travel drive or implement hydraulics. (orig.)

  5. The ubiquitous photonic wheel

    Science.gov (United States)

    Aiello, Andrea; Banzer, Peter

    2016-08-01

    A circularly polarized electromagnetic plane wave carries an electric field that rotates clockwise or counterclockwise around the propagation direction of the wave. According to the handedness of this rotation, its longitudinal spin angular momentum (AM) density is either parallel or antiparallel to the propagation of light. However, there are also light waves that are not simply plane and carry an electric field that rotates around an axis perpendicular to the propagation direction, thus yielding transverse spin AM density. Electric field configurations of this kind have been suggestively dubbed ‘photonic wheels’. It has been recently shown that photonic wheels are commonplace in optics as they occur in electromagnetic fields confined by waveguides, in strongly focused beams, in plasmonic and evanescent waves. In this work we establish a general theory of electromagnetic waves propagating along a well defined direction, and carrying transverse spin AM density. We show that depending on the shape of these waves, the spin density may be either perpendicular to the mean linear momentum (globally transverse spin) or to the linear momentum density (locally transverse spin). We find that the latter case generically occurs only for non-diffracting beams, such as the Bessel beams. Moreover, we introduce the concept of meridional Stokes parameters to operationally quantify the transverse spin density. To illustrate our theory, we apply it to the exemplary cases of Bessel beams and evanescent waves. These results open a new and accessible route to the understanding, generation and manipulation of optical beams with transverse spin AM density.

  6. A development of the distributive law of points on the multi-wheeled machine wheels with electro-mechanical transmission, made under the scheme "motor-axis"

    Directory of Open Access Journals (Sweden)

    M. M. Jileikin

    2014-01-01

    Full Text Available Currently, developers of multi-wheeled vehicles (MWV show growing interest in electromechanical drive in the «motor-axis» implementation. However, in designing the traction electric drive (TED based on such approach the problems arise, primarily, from a lack of creating experience and of ready algorithmic solutions to control the traction motors. The use of methods to implement the individual TED is impossible because of the presence of cross-axle differential in the leading axle drive, which does not allow the input torque control of each wheel singly. The paper offers a law to control a traction electric drive of MWV leading axles that comprises the law to control the tractive effort torque and braking moment on the leading axles as well as algorithms of anti-lock brake and traction control systems.An analysis of simulation modeling results shows an efficiency of the developed law that allows control of the traction electric drive of MWV leading axles. The control law includes an algorithm to control the tractive effort torque and braking moment on the driving-wheels, as well as algorithms of anti-lock brake and traction systems.At stationary (constant speed rotation and non-stationary (elk test maneuvering there was no spin of vehicle wheels. Angular speeds of the wheels vary smoothly. Partial loss of vehicle stability when making maneuvers on ice may be reduced through development of algorithms for dynamic stabilization, which will improve the MWV road-holding and trajectory ability. Fullscale tests of MWV with traction electric drive implemented using a “motor-axis" approach are required to have a final answer on the performance and effectiveness of the developed control law.

  7. Rating forces grip and driving and accelerations of the car with drive different configuration

    Directory of Open Access Journals (Sweden)

    Kowalski Mariusz

    2015-12-01

    Full Text Available The paper shows a typical drive systems used in today's vehicles, mainly cars. Approximated scheme of the formation of the driving force of the vehicle and the necessary mathematical relations for the calculation. For example, a typical passenger car BMW 320 was analyzed and calculations obtained a driving force, of adhesion and acceleration. The calculations were performed for the drive system, the classical (i.e. the rear axle of the vehicle for front-wheel drive and four-wheel drive (4×4. Virtually assumed that to the above mentioned vehicle it is possible buildings of each of said system. These are shown graphically in diagrams bearing a distribution of the forces acting on the substrate and the reactions - the data necessary for the calculations. The resulting calculation is graphically shown in the diagrams, in which is illustrated a change value of the resulting adhesive strength, and the acceleration depending on the drive type vehicle.

  8. Magnetically suspended momentum wheels for spacecraft stabilization

    Science.gov (United States)

    Henrikson, C. H.; Lyman, J.; Studer, P. A.

    1974-01-01

    Magnetic bearings for spacecraft momentum wheels offer the promise of low friction and unlimited life. This paper describes how magnetic bearings work and their advantages and disadvantages. The present status of magnetic bearings is described and examples are shown of the various and widely-different magnetically suspended momentum wheels that have been built to date. These include wheels whose bearings exhibit high stiffness and wheels with zero-power suspensions. The future of magnetically suspended momentum wheels is discussed including the possibility of wheels with neither spokes nor shaft.

  9. Performance Evaluation of an In-Wheel Motor Cooling System in an Electric Vehicle/Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Dong Hyun Lim

    2014-02-01

    Full Text Available High power and miniaturization of motors in an in-wheel drive system, which is installed inside the wheels of a vehicle, are required for directly driving the wheels. In addition, an efficient cooling system is required to ensure high driving performance and durability. This study experimentally evaluated the heat dissipation performance of a 35-kW-class large-capacity in-wheel motor equipped with an internal-circulation-type oil-cooling system that exhibits high cooling performance and can be easily miniaturized to this motor. Temperatures of the coil and stator core of cooling systems with and without a radiator were measured in real time under in-wheel motor driving conditions. It was found that operating the cooling system at a continuous-rating maximum speed without the radiator was difficult. We confirmed that under continuous-rating base speed and continuous-rating maximum speed driving conditions, the cooling system with the radiator showed thermally stable operation. Furthermore, under maximum-rating base speed and maximum-rating maximum speed driving conditions, the cooling system with the radiator provided additional driving times of approximately 22 s and 2 s, respectively.

  10. Improvement of the lunar rover with two parallel wheels

    Science.gov (United States)

    Bi, Z. F.; Deng, Z. Q.; Tao, J. G.

    With raising the new upsurge for lunar exploration the lunar rover with two parallel wheels is proposed for lunar exploration The lunar rover is driven by the offset of the driving weight and it is selected as the subsystem of the lunar rover group system The communication among the lunar rover group is simulated with blue-tooth technology In the group system the characteristic and the stability are the key problems for application The lunar rover has simple structure and it is controlled easily and also it has more performance such as motion flexibility antidumping combinability The lunar rover is composed of two wheels and a case platform Each wheel is controlled independently On the top of the case platform CCD is used for navigation In the front and the back of the case platform there are docking mechanism for combination The precise speed and position of the lunar rover is controlled by PMAC With PC 104 the actual load such as the information of sensors and real-time communication via blue-tooth is processed The good stability of the lunar rover is favorable for vision navigation and combination of several rovers Focused on the stability the lunar rover with changeable radius is proposed Screw pair is used in the lunar rover system for adjusting the driving radius Through adjusting the driving radius the tilt angle of the case platform can be variant value under the same driving moment and also the tilt angle can keep equal under the variant driving moment For testing the feasibility of the scheme based on the

  11. Two new wheels for ATLAS

    CERN Multimedia

    2002-01-01

    Juergen Zimmer (Max Planck Institute), Roy Langstaff (TRIUMF/Victoria) and Sergej Kakurin (JINR), in front of one of the completed wheels of the ATLAS Hadronic End Cap Calorimeter. A decade of careful preparation and construction by groups in three continents is nearing completion with the assembly of two of the four 4 m diameter wheels required for the ATLAS Hadronic End Cap Calorimeter. The first two wheels have successfully passed all their mechanical and electrical tests, and have been rotated on schedule into the vertical position required in the experiment. 'This is an important milestone in the completion of the ATLAS End Cap Calorimetry' explains Chris Oram, who heads the Hadronic End Cap Calorimeter group. Like most experiments at particle colliders, ATLAS consists of several layers of detectors in the form of a 'barrel' and two 'end caps'. The Hadronic Calorimeter layer, which measures the energies of particles such as protons and pions, uses two techniques. The barrel part (Tile Calorimeter) cons...

  12. Self-driving carsickness.

    Science.gov (United States)

    Diels, Cyriel; Bos, Jelte E

    2016-03-01

    This paper discusses the predicted increase in the occurrence and severity of motion sickness in self-driving cars. Self-driving cars have the potential to lead to significant benefits. From the driver's perspective, the direct benefits of this technology are considered increased comfort and productivity. However, we here show that the envisaged scenarios all lead to an increased risk of motion sickness. As such, the benefits this technology is assumed to bring may not be capitalised on, in particular by those already susceptible to motion sickness. This can negatively affect user acceptance and uptake and, in turn, limit the potential socioeconomic benefits that this emerging technology may provide. Following a discussion on the causes of motion sickness in the context of self-driving cars, we present guidelines to steer the design and development of automated vehicle technologies. The aim is to limit or avoid the impact of motion sickness and ultimately promote the uptake of self-driving cars. Attention is also given to less well known consequences of motion sickness, in particular negative aftereffects such as postural instability, and detrimental effects on task performance and how this may impact the use and design of self-driving cars. We conclude that basic perceptual mechanisms need to be considered in the design process whereby self-driving cars cannot simply be thought of as living rooms, offices, or entertainment venues on wheels.

  13. Propulsion Wheel Motor for an Electric Vehicle

    Science.gov (United States)

    Figuered, Joshua M. (Inventor); Herrera, Eduardo (Inventor); Waligora, Thomas M. (Inventor); Bluethmann, William J. (Inventor); Farrell, Logan Christopher (Inventor); Lee, Chunhao J. (Inventor); Vitale, Robert L. (Inventor); Winn, Ross Briant (Inventor); Eggleston, IV, Raymond Edward (Inventor); Guo, Raymond (Inventor); hide

    2016-01-01

    A wheel assembly for an electric vehicle includes a wheel rim that is concentrically disposed about a central axis. A propulsion-braking module is disposed within an interior region of the wheel rim. The propulsion-braking module rotatably supports the wheel rim for rotation about the central axis. The propulsion-braking module includes a liquid cooled electric motor having a rotor rotatable about the central axis, and a stator disposed radially inside the rotor relative to the central axis. A motor-wheel interface hub is fixedly attached to the wheel rim, and is directly attached to the rotor for rotation with the rotor. The motor-wheel interface hub directly transmits torque from the electric motor to the wheel rim at a 1:1 ratio. The propulsion-braking module includes a drum brake system having an electric motor that rotates a cam device, which actuates the brake shoes.

  14. Reaction Wheel Disturbance Model Extraction Software Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Reaction wheel disturbances are some of the largest sources of noise on sensitive telescopes. Such wheel-induced mechanical noises are not well characterized....

  15. Experimental heat and mass transfer of the separated and coupled rotating desiccant wheel and heat wheel

    Energy Technology Data Exchange (ETDEWEB)

    Enteria, Napoleon; Yoshino, Hiroshi; Mochida, Akashi; Takaki, Rie [Graduate School of Engineering, Tohoku University, Sendai 980-8579 (Japan); Satake, Akira [Technical Research Institute, Maeda Corporation, Tokyo 179-8914 (Japan); Yoshie, Ryuichiro [Faculty of Engineering, Tokyo Polytechnic University, Atsugi 243-0297 (Japan); Mitamura, Tiruaki [Faculty of Engineering, Ashikaga Institute of Technology, Ashikaga 326-8558 (Japan); Baba, Seizo [Earth Clean Tohoku Co., Ltd., Sendai 984-0038 (Japan)

    2010-07-15

    The experimental evaluation of the separated and coupled rotating desiccant wheel and heat wheel is reported. The study aims to investigate the performance of the desiccant wheel and of the heat wheel both when operated separately and jointly. The performance evaluation of the desiccant wheel is based on its moisture removal capacity (MRC), moisture removal regeneration (MRR), and moisture mass balance (MMB). In addition, the study used the total energy balance (TEB), sensible coefficient of performance (COP{sub Sensible}), latent coefficient of performance (COP{sub Latent}) and, total coefficient of performance (COP{sub Total}). The performance of the heat wheel is based on its effectiveness. The COP{sub Sensible}, COP{sub Latent} and, COP{sub Total} are used in the performance evaluation of the coupled desiccant wheel and heat wheel. The general results of the study show that the MRC, MRR and MMB coupled with the TEB, COP{sub Latent}, COP{sub Sensible} and COP{sub Total} predict adequately the performance of the desiccant wheel. In addition, the coupled operation of the desiccant wheel and heat wheel, contributed to the reduction of the external thermal energy requirement for the regeneration of the desiccant wheel. This study can be applied in other researches seeking evaluation of the desiccant wheel, heat wheel, and their combined operation. Moreover, the data presented here are significant for the desiccant wheel benchmarking and for evaluation of the desiccant wheel models. (author)

  16. Soil Parameter Identification for Wheel-terrain Interaction Dynamics and Traversability Prediction

    Institute of Scientific and Technical Information of China (English)

    Suksun Hutangkabodee; Yahya Hashem Zweiri; Lakmal Dasarath Seneviratne; Kaspar Althoefer

    2006-01-01

    This paper presents a novel technique for identifying soil parameters for a wheeled vehicle traversing unknown terrain. The identified soil parameters are required for predicting vehicle drawbar pull and wheel drive torque, which in turn can be used for traversability prediction, traction control, and performance optimization of a wheeled vehicle on unknown terrain. The proposed technique is based on the Newton Raphson method. An approximated form of a wheel-soil interaction model based on Composite Simpson's Rule is employed for this purpose. The key soil parameters to be identified are internal friction angle, shear deformation modulus, and lumped pressure-sinkage coefficient. The fourth parameter, cohesion, is not too relevant to vehicle drawbar pull, and is assigned an average value during the identification process. Identified parameters are compared with known values, and shown to be in agreement. The identification method is relatively fast and robust.The identified soil parameters can effectively be used to predict drawbar pull and wheel drive torque with good accuracy.The use of identified soil parameters to design a traversability criterion for wheeled vehicles traversing unknown terrain is presented.

  17. 49 CFR 230.112 - Wheels and tires.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Wheels and tires. 230.112 Section 230.112... Tenders Wheels and Tires § 230.112 Wheels and tires. (a) Mounting. Wheels shall be securely mounted on... wheels mounted on the same axle shall not vary more than 1/4 inch. (d) Tire thickness. Wheels may...

  18. Stability Simulation of a Vehicle with Wheel Active Steering

    Directory of Open Access Journals (Sweden)

    Brabec Pavel

    2016-01-01

    Full Text Available This paper deals with the possibility of increasing the vehicle driving stability at a higher speed. One of the ways how to achieve higher stability is using the 4WS system. Mathematical description of vehicle general movement is a very complex task. For simulation, models which are aptly simplified are used. For the first approach, so-called single-truck vehicle model (often linear is usually used. For the simulation, we have chosen to extend the model into a two-truck one, which includes the possibility to input more vehicle parameters. Considering the 4WS system, it is possible to use a number of potential regulations. In our simulation model, the regulation system with compound coupling was used. This type of regulation turns the rear wheels depending on the input parameters of the system (steering angle of the front wheels and depending on the output moving quantities of the vehicle, most frequently the yaw rate. Criterion for compensation of lateral deflection centre of gravity angle is its zero value, or more precisely the zero value of its first-order derivative. Parameters and set-up of the simulation model were done in conjunction with the dSAPACE software. Reference performances of the vehicle simulation model were made through the defined manoeuvres. But the simulation results indicate that the rear-wheels steering can have a positive effect on the vehicle movement stability, especially when changing the driving direction at high speed.

  19. GMT azimuth bogie wheel-rail interface wear study

    Science.gov (United States)

    Teran, Jose; Lindh, Cory; Morgan, Chris; Manuel, Eric; Bigelow, Bruce C.; Burgett, William S.

    2016-07-01

    Performance of the GMT azimuth drive system is vital for the operation of the telescope and, as such, all components subject to wear at the drive interface merit a high level of scrutiny for achieving a proper balance between capital costs, maintenance costs, and the risk for downtime during planned and unplanned maintenance or replacement procedures. Of particular importance is the interface between the azimuth wheels and rail, as usage frequency is high, the full weight of the enclosure must be transferred through small patches of contact, and replacement of the rail would pose a greater logistical challenge than the replacement of smaller components such as bearings and gearmotors. This study investigates tradeoffs between various wheel-rail and roller-track interfaces, including performance, complexity, and anticipated wear considerations. First, a survey of railway and overhead crane industry literature is performed and general detailing recommendations are made to minimize wear and the risk of rolling contact fatigue. Second, Adams/VI-Rail is used to simulate lifetime wear of four specific configurations under consideration for the GMT azimuth wheel-rail interface; all studied configurations are shown to be viable, and their relative merits are discussed.

  20. Motion Control of Wheeled Mobile Robots

    Directory of Open Access Journals (Sweden)

    Birol Kocaturk

    2015-01-01

    Full Text Available This article presents strategy for navigation of a wheeled mobile robot in unstructured environments with obstacles. The vehicle has two wheels independently to control the angular velocity. This work deals with mobile robots modelling then control strategies and simulation results. Simulation results recommends fuzzy logic controller for the wheeled mobile robot motion in unstructured environments.

  1. Supplementary magnetic tests for railway wheel sets

    Directory of Open Access Journals (Sweden)

    Zbigniew Hilary ŻUREK

    2008-01-01

    Full Text Available During manufacturing process the wheel set is subjected to many different flaw detection methods; however, these methods are not sufficient while the wheel set is in service. The paper presents an example of monitoring of magnetic parameters changes of wheel set rolling surface (changes result from material degradation due to materialfatigue.

  2. Before the Outline--The Writing Wheel.

    Science.gov (United States)

    Rae, Colleen

    1990-01-01

    Illustrates the use of the writing wheel, a prewriting technique for writing from thesis statements that requires students to create a picture of a wheel. Shows how the wheel can be used in writing paragraphs and how it can be combined with summary writing to produce an integrated term paper. (DB)

  3. Roughness on Dutch railway wheels and rails

    NARCIS (Netherlands)

    Dings, P.C.; Dittrich, M.G.

    1996-01-01

    Surface roughness on 150 railway wheels and on the rails of 30 sites in the Netherlands have been measured. Block braked wheels were found to show higher roughnesses than the rail at any site. The smoothest rail is 8 dB smoother than the smoothest wheel. It was concluded that in reducing railway

  4. Interaction of In-wheel Permanent Magnet Synchronous Motor with Tire Dynamics

    Institute of Scientific and Technical Information of China (English)

    SONG Ziyou; LI Jianqiu; WEI Yintao; XU Liangfei; OUYANG Minggao

    2015-01-01

    Drive wheel systems combined with the in-wheel permanent magnet synchronous motor (I-PMSM) and the tire are highly electromechanical-coupled. However, the deformation dynamics of this system, which may influence the system performance, is neglected in most existing literatures. For this reason, a deformable tire and a detalled I-PMSM are modeled using Matlab/Simulink. Furthermore, the influence of tire/road contact interface is accurately described by the non-linear relaxation length-based model and magic formula pragmatic model. The drive wheel model used in this paper is closer to that of a real tire in contrast to the rigid tire model which is widely used. Based on the near-precise model mentioned above, the sensitivity of the dynamic tire and I-PMSM parameters to the relative error of slip ratio estimation is analyzed. Additionally, the torsional and longitudinal vibrations of the drive wheel are presented both in time and frequency domalns when a quarter vehicle is started under conditions of a specific torque curve, which includes an abrupt torque change from 30 N•m to 200 N•m. The parameters sensitivity on drive wheel vibrations is also studied, and the parameters include the mass distribution ratio of tire, the tire torsional stiffness, the tire damping coefficient, and the hysteresis band of the PMSM current control algorithm. Finally, different target torque curves are compared in the simulation, which shows that the estimation error of the slip ratio gets violent, and the longitudinal force includes more fluctuation components with the increasing change rate of the torque. This paper analyzes the influence of the drive wheel deformation on the vehicle dynamic control, and provides useful information regarding the electric vehicle traction control.

  5. Factors associated with falling asleep at the wheel among long-distance truck drivers.

    Science.gov (United States)

    McCartt, A T; Rohrbaugh, J W; Hammer, M C; Fuller, S Z

    2000-07-01

    Data on the prevalence and hypothesized predictors of falling asleep while driving were gathered through face-to-face interviews with 593 long-distance truck drivers randomly selected at public and private rest areas and routine roadside truck safety inspections. Hypothesized predictor variables related to drivers' typical work and rest patterns, extent of daytime and night-time drowsiness, symptoms of sleep disorder, measures of driving exposure, and demographic characteristics. A sizeable proportion of long-distance truck drivers reported falling asleep at the wheel of the truck: 47.1% of the survey respondents had ever fallen asleep at the wheel of a truck, and 25.4% had fallen asleep at the wheel in the past year. Factor analysis reduced the large set of predictors to six underlying, independent factors: greater daytime sleepiness; more arduous schedules, with more hours of work and fewer hours off-duty; older, more experienced drivers; shorter, poorer sleep on road; symptoms of sleep disorder; and greater tendency to night-time drowsy driving. Based on multivariate logistic regression, all six factors were predictive of self-reported falling asleep at the wheel. Falling asleep was also associated with not having been alerted by driving over shoulder rumble strips. The results suggest that countermeasures that limit drivers' work hours and enable drivers to get adequate rest and that identify drivers with sleep disorders are appropriate methods to reduce sleepiness-related driving by truck drivers.

  6. Getting Off the Hamster Wheel

    Science.gov (United States)

    Sammon, Grace

    2005-01-01

    Even with all the external elements of school reform in place, educators can end up spinning their wheels. To make progress, schools must identify the nonnegotiable key elements of their reform plans and use the habits of highly effective schools to turn them into school practice. These habits are: (1) demonstrate high expectations and a vision…

  7. Simulation modeling of wheeled vehicle dynamics on the stand "Roller"

    Directory of Open Access Journals (Sweden)

    G. O. Kotiev

    2014-01-01

    Full Text Available The tests are an integral part of the wheeled vehicle design, manufacturing, and operation. The need for their conducting arises from the research and experimental activities to assess the qualitative and quantitative characteristics of the vehicles in general, as well as the individual components and assemblies. It is obvious that a variety of design features of wheeled vehicles request a development of methods both for experimental studies and for creating the original bench equipment for these purposes.The main positive feature of bench tests of automotive engineering is a broad capability to control the combinations of traction loads, speed rates, and external input conditions. Here, the steady state conditions can be used for a long time, allowing all the necessary measurements to be made, including those with video and photo recording experiment.It is known that the benefits of test "M" type (using a roller dynamometer include a wide range of test modes, which do not depend on the climatic conditions, as well as a capability to use a computer-aided testing programs. At the same time, it is known that the main drawback of bench tests of full-size vehicle is that the tire rolling conditions on the drum mismatch to the real road pavements, which are difficult to simulate on the drum surface. This problem can be solved owing to wheeled vehicle tests at the benches "Roller" to be, in efficiency, the most preferable research method. The article gives a detailed presentation of developed at BMSTU approach to its solving.Problem of simulation mathematical modeling has been solved for the vehicle with the wheel formula 8 × 8, and individual wheel-drive.The simulation results have led to the conclusion that the proposed principle to simulate a vehicle rolling on a smooth non-deformable support base using a bench " Roller " by simulation modeling is efficient.

  8. Some peculiarities of corrosion of wheel steel

    Directory of Open Access Journals (Sweden)

    Alexander SHRAMKO

    2009-01-01

    Full Text Available Corrosion mechanism and rate of different chemical composition and structural condition of wheel steel were investigated. It was shown that “white layers”, variation in grain size and banding of wheel steel structure results in corrosion rate. Microstructure of steel from different elements of railway wheels after operation with corrosion was investigated. Wheel steel with addition of vanadium corroded more quickly than steel without vanadium. Non-metallic inclusions are the centre of corrosion nucleation and their influence on corrosion depends on type of inclusion. Mechanism of corrosion of wheel steel corrosion was discussed.

  9. An amendatory dynamic model with slip for four-wheeled omni-directional mobile robot

    Science.gov (United States)

    Cao, Qixin; Huang, Yanwen; Leng, Chuntao

    2007-12-01

    Compared with the common differential driving ones, omni-directional mobile robots (OMRs) have more agilely locomotion performance, which therefore have been applied in many fields. One kind of four-wheeled OMR used in RoboCup Middle Size League competition is presented in this paper. Its kinematics and dynamic model is introduced. And considering the independent drive of four wheels which creates inevitable slipping in motion, the amendatory dynamics model that includes slipping between the wheels and the motion surface is presented. Based on the above slipping model, the velocity feedback PID controller implemented by DSP as the kernel is also given here. Experiments results demonstrate the feasibility of the dynamic model and controller.

  10. WheelWalker: a foot-wheel driving exoskeleton for the alternate walk of paraplegic patients

    Directory of Open Access Journals (Sweden)

    Ma Qingchuan

    2017-01-01

    Full Text Available Upright walk is the fundamental need of paraplegic patients. In this study, we proposed a novel lower-limb exoskeleton for assisting the patients to walk alternately and further improve their engagement in the rehabilitation training. The exoskeleton was driven by a hub motor which was mounted under the foot, and a pair of custom-made crutch with wireless controller was used to control the walking condition of exoskeleton and maintain balance. This paper mainly introduced the general designing concept and detailed specifications of each modules of the exoskeleton. A pilot using experiment was performed on two healthy subjects to qualitatively analyse the capability of this exoskeleton when adopting different gaits. The results showed that the subjects with different body characteristics could complete continued walk by wearing this exoskeleton either in a three-point gait mode or four-point gait mode.

  11. Model-based analysis of wheel speed vibrations for road friction classification using MF-Swift

    NARCIS (Netherlands)

    Schmeitz, A.J.C.; Alirezaei, M.

    2015-01-01

    With higher level of vehicle automation, it becomes increasingly important to know the maximum possible tyre forces during normal driving. An interesting method in this respect is estimating the tyre-road friction from the resonance in the wheel speed signal, excited by road roughness. A simulation

  12. Reconsidering Technological Transmission : The Introduction of the Potter’s Wheel at Ayia Irini, Kea, Greece

    NARCIS (Netherlands)

    Gorogianni, E.; Abell, N.; Hilditch, J.

    2016-01-01

    This article examines processes of cultural and technological transmission by focusing on the effects of the introduction of the potter’s wheel. Since distinct production choices are tied to both micro- and macroscale processes that drive change in material culture, a study of such choices provides

  13. Wheel of concert hall acoustics

    OpenAIRE

    Kuusinen, A.; Lokki, T.

    2017-01-01

    More than a hundred years of research on concert hall acoustics has provided an extensive list of attributes to describe and evaluate the perceptual aspects of sound in concert halls. This brief overview discusses the current knowledge, and presents a "wheel of concert hall acoustics" in which the main aspects are gathered together with the descriptive attributes that are commonly encountered in the research literature. Peer reviewed

  14. Drive Stands

    Data.gov (United States)

    Federal Laboratory Consortium — The Electrical Systems Laboratory (ESL)houses numerous electrically driven drive stands. A drive stand consists of an electric motor driving a gearbox and a mounting...

  15. Friction self-oscillation decrease in nonlinear system of locomotive traction drive

    Science.gov (United States)

    Antipin, D. Ya; Vorobiyov, V. I.; Izmerov, O. V.; Shorokhov, S. G.; Bondarenko, D. A.

    2017-02-01

    The problems of the friction self-oscillation decrease in a nonlinear system of a locomotive traction drive are considered. It is determined that the self-oscillation amplitude decrease in a locomotive wheel pair during boxing in traction drives with an elastic linkage between an armature of a traction electric motor and gearing can be achieved due to drive damping capacity during impact vibro-damping in an axle reduction gear with a hard driven gear. The self-oscillation amplitude reduction in a wheel pair in the designs of locomotive traction drives with the location of elastic elements between a wheel pair and gearing can be obtained owing to the application of drive inertial masses as an anti-vibrator. On the basis of the carried out investigations, a design variant of a self-oscillation shock absorber of a traction electric motor framework on a reduction gear suspension with an absorber located beyond a wheel-motor unit was offered.

  16. MOBILITY EVALUATION AND INNOVATION OF WHEELED SPACE ROVER

    Institute of Scientific and Technical Information of China (English)

    SHANG Jianzhong; LUO Zirong; LI Shengyi; TANG Li

    2006-01-01

    The mission and function requirements of lunar rover are analyzed, based on virtual prototype technology, the mobility evaluation theory and method for wheeled space rover are proposed,which provide a new way to study the innovative design of lunar rover. Based on the above theoretical system, an innovative lunar rover suspension system, which adopts a two-crank-slider mechanism, is proposed, and its dynamics model is created. Adopting virtual prototype technology, the ground adaptability, over-obstacle ability and driving placidity of the rover are evaluated in the virtual prototype software ADAMS. The analysis results show that the rover provides a high degree of mobility.

  17. Generic trajectory representation and trajectory following for wheeled robots

    DEFF Research Database (Denmark)

    Kjærgaard, Morten; Andersen, Nils Axel; Ravn, Ole

    2014-01-01

    This article presents the work towards a purely generic navigation solution for wheeled mobile robots motivated by the following goals: Generic: Works for different types of robots. Configurable: Parameters maps to geometric properties of the robot. Predictable: Well defined where the robot...... will drive. Safe: Avoid fatal collisions. Based on a survey of existing methods and algorithms the article presents a generic way to represent constraints for different types of robots, a generic way to represent trajectories using Bëzier curves, a method to convert the trajectory so it can be driven...

  18. A study on high-speed rolling contact between a wheel and a contaminated rail

    Science.gov (United States)

    Zhao, Xin; Wen, Zefeng; Zhu, Minhao; Jin, Xuesong

    2014-10-01

    A 3-D explicit finite element model is developed to investigate the transient wheel-rail rolling contact in the presence of rail contamination or short low adhesion zones (LAZs). A transient analysis is required because the wheel passes by a short LAZ very quickly, especially at high speeds. A surface-to-surface contact algorithm (by the penalty method) is employed to solve the frictional rolling contact between the wheel and the rail meshed by solid elements. The LAZ is simulated by a varying coefficient of friction along the rail. Different traction efforts and action of the traction control system triggered by the LAZ are simulated by applying a time-dependent driving torque to the wheel axle. Structural flexibilities of the vehicle-track system are considered properly. Analysis focuses on the contact forces, creepage, contact stresses and the derived frictional work and plastic deformation. It is found that the longitudinal contact force and the maximum surface shear stress in the contact patch become obviously lower in the LAZ and much higher as the wheel re-enters the dry rail section. Consequently, a higher wear rate and larger plastic flow are expected at the location where the dry contact starts to be rebuilt. In other words, contact surface damages such as wheel flats and rail burns may come into being because of the LAZ. Length of the LAZ, the traction level, etc. are varied. The results also show that local contact surface damages may still occur as the traction control system acts.

  19. Reaction wheels for kinetic energy storage

    Science.gov (United States)

    Studer, P. A.

    1984-01-01

    In contrast to all existing reaction wheel implementations, an order of magnitude increase in speed can be obtained efficiently if power to the actuators can be recovered. This allows a combined attitude control-energy storage system to be developed with structure mounted reaction wheels. The feasibility of combining reaction wheels with energy storage wwheels is demonstrated. The power required for control torques is a function of wheel speed but this energy is not dissipated; it is stored in the wheel. The I(2)R loss resulting from a given torque is shown to be constant, independent of the design speed of the motor. What remains, in order to efficiently use high speed wheels (essential for energy storage) for control purposes, is to reduce rotational losses to acceptable levels. Progress was made in permanent magnet motor design for high speed operation. Variable field motors offer more control flexibility and efficiency over a broader speed range.

  20. ATLAS- lowering the muon small wheel

    CERN Multimedia

    CERN Audiovisual Service

    2008-01-01

    ATLAS - the two muon small wheels lowered into the cavern Like briefly separated twin sisters, ATLAS’s small wheels were once again united at the experiment’s surface building at Point 1 on St Valentine’s Day. The lowering of the small wheels into the tunnel will mark the end of the installation of detector components for the experiment. At around 15.40 on Friday 29th February the ATLAS collaboration cracked open the champagne as the second of the small wheels was lowered into the cavern.

  1. ATLAS- lowering the muon small wheel

    CERN Multimedia

    2008-01-01

    ATLAS - the two muon small wheels lowered into the cavern Like briefly separated twin sisters, ATLAS’s small wheels were once again united at the experiment’s surface building at Point 1 on St Valentine’s Day. The lowering of the small wheels into the tunnel will mark the end of the installation of detector components for the experiment. At around 15.40 on Friday 29th February the ATLAS collaboration cracked open the champagne as the second of the small wheels was lowered into the cavern.

  2. Modelling of a mecanum wheel taking into account the geometry of road rollers

    Science.gov (United States)

    Hryniewicz, P.; Gwiazda, A.; Banaś, W.; Sękala, A.; Foit, K.

    2017-08-01

    During the process planning in a company one of the basic factors associated with the production costs is the operation time for particular technological jobs. The operation time consists of time units associated with the machining tasks of a workpiece as well as the time associated with loading and unloading and the transport operations of this workpiece between machining stands. Full automation of manufacturing in industry companies tends to a maximal reduction in machine downtimes, thereby the fixed costs simultaneously decreasing. The new construction of wheeled vehicles, using Mecanum wheels, reduces the transport time of materials and workpieces between machining stands. These vehicles have the ability to simultaneously move in two axes and thus more rapid positioning of the vehicle relative to the machining stand. The Mecanum wheel construction implies placing, around the wheel free rollers that are mounted at an angle 450, which allow the movement of the vehicle not only in its axis but also perpendicular thereto. The improper selection of the rollers can cause unwanted vertical movement of the vehicle, which may cause difficulty in positioning of the vehicle in relation to the machining stand and the need for stabilisation. Hence the proper design of the free rollers is essential in designing the whole Mecanum wheel construction. It allows avoiding the disadvantageous and unwanted vertical vibrations of a whole vehicle with these wheels. In the article the process of modelling the free rollers, in order to obtain the desired shape of unchanging, horizontal trajectory of the vehicle is presented. This shape depends on the desired diameter of the whole Mecanum wheel, together with the road rollers, and the width of the drive wheel. Another factor related with the curvature of the trajectory shape is the length of the road roller and its diameter decreases depending on the position with respect to its centre. The additional factor, limiting construction of

  3. Finite element simulation of wheel impact test

    Directory of Open Access Journals (Sweden)

    S.H. Yang

    2008-06-01

    Full Text Available Purpose: In order to achieve better performance and quality, the wheel design and manufacturing use a number of wheel tests (rotating bending test, radial fatigue test, and impact test to insure that the wheel meets the safety requirements. The test is very time consuming and expensive. Computer simulation of these tests can significantly reduce the time and cost required to perform a wheel design. In this study, nonlinear dynamic finite element is used to simulate the SAE wheel impact test.Design/methodology/approach: The test fixture used for the impact test consists of a striker with specified weight. The test is intended to simulate actual vehicle impact conditions. The tire-wheel assembly is mounted at 13° angle to the vertical plane with the edge of the weight in line with outer radius of the rim. The striker is dropped from a specified height above the highest point of the tire-wheel assembly and contacts the outboard flange of the wheel.Because of the irregular geometry of the wheel, the finite element model of an aluminium wheel is constructed by tetrahedral element. A mesh convergence study is carried out to ensure the convergence of the mesh model. The striker is assumed to be rigid elements. Initially, the striker contacts the highest area of the wheel, and the initial velocity of the striker is calculated from the impact height. The simulated strains at two locations on the disc are verified by experimental measurements by strain gages. The damage parameter of a wheel during the impact test is a strain energy density from the calculated result.Findings: The prediction of a wheel failure at impact is based on the condition that fracture will occur if the maximum strain energy density of the wheel during the impact test exceeds the total plastic work of the wheel material from tensile test. The simulated results in this work show that the total plastic work can be effectively employed as a fracture criterion to predict a wheel

  4. Single wheel hub motor failures and their impact on vehicle and driver behaviour

    Science.gov (United States)

    Wanner, Daniel; Kreußlein, Maria; Augusto, Bruno; Drugge, Lars; Stensson Trigell, Annika

    2016-10-01

    This research work studies the impact of single wheel hub motor failures on the dynamic behaviour of electric vehicles and the corresponding driver reactions. An experimental study in a moving-base driving simulator is conducted to analyse the influence of single wheel hub motor failures for motorway speeds. Driver reaction times are derived from the measured data and discussed in their experimental context. The failure is rated objectively on the dynamic behaviour of the vehicle and compared to the subjective evaluation. Findings indicate that critical traffic situations impairing traffic safety can occur for motorway speeds. Clear counteractions by the drivers had to be taken.

  5. The energy wheel in operation

    Science.gov (United States)

    Barthelemy, J. P.

    An energy wheel was implemented as an uninterruptible power supply unit for a rural telephone exchange. A high speed rotor, magnetically suspended, inside a vacuum container, is activated by a brushless motor. Being reversible, this motor acts as an electrical energy generator in case of failure or microcuts from the mains. No failure, no maintenance, no detrimental effect of cold winter environment, and satisfactory level of available back up energy are reported. Improvements such as mass reduction, easy implementation, vacuum tightness, and ac supply are identified.

  6. 16 CFR 1507.8 - Wheel devices.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Wheel devices. 1507.8 Section 1507.8... FIREWORKS DEVICES § 1507.8 Wheel devices. Drivers in fireworks devices commonly known as “wheels” shall be securely attached to the device so that they will not come loose in transportation, handling, and...

  7. 49 CFR 215.103 - Defective wheel.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System § 215.103 Defective wheel. A railroad may not place or continue in service a car, if— (a) A wheel flange on the car is worn to a thickness of 7/8 of an inch, or less, at a point 3/8 of an inch above...

  8. A Full Disturbance Model for Reaction Wheels

    NARCIS (Netherlands)

    Le, M.P.; Ellenbroek, Marcellinus Hermannus Maria; Seiler, R; van Put, P.; Cottaar, E.J.E.

    2014-01-01

    Reaction wheels are rotating devices used for the attitude control of spacecraft. However, reaction wheels also generate undesired disturbances in the form of vibrations, which may have an adverse effect on the pointing accuracy and stability of spacecraft (optical) payloads. A disturbance model for

  9. Biaxial wheel/hub test facility. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, G.; Grubisic, V. [eds.

    2000-07-01

    The 4{sup th} meeting aims to exchange the experience and knowledge of engineers during several presentations and discussions about new developments required for a reliable, time and cost reducing validation of the wheel/hub assembly. Tremendous development of the wheel performance, described by the ratio of the rated load (kg) versus the wheel weight (kg) had taken place during the last 5000 years. Starting from the ratio of 3 for wooden 2-piece-disc-wheels in Mesopotamia it needed nearly 1000 years to increase the ratio to approx 5 at light-weight spoke wheels for fighting carriages, found in the grave of king Tutenchamon in Egypt. Modern light alloy wheels of commercial vehicles reach values up to 160 kg/kg. Additionally the comlex design of the modern systems for cars and commercial vehicles comprising wheel, brake, hub, bearing, spindle and hub carrier, including different materials and their treatment, fasteners, press-fits, require an appropriate testing procedure. The variable loading conditions, caused by operational wheel forces, brake and torque moments including heating, may result in changing tolerances and press-fits during operation and consequently in different damage mechanisms. This can be simulated in the Biaxial Wheel Test Machine, whereby corresponding load programs are necessary. An overview about all biaxial test machines in usage at the end of 1999 is shown in the introduction. The total number is 17 for cars, 7 for commercial vehicles and 1 for trains. The six presentations of this meeting were consequently concentrated on: (a) recommendations for a standardization of load programs of the German Wheel Committee, (b) the simulation of brake and torque events and (c) the possibility for a numerical stress analyses and fatigue life assessment. (orig./AKF)

  10. Drugged Driving

    Science.gov (United States)

    ... Parents & Educators Children & Teens Search Connect with NIDA : Google Plus Facebook LinkedIn Twitter YouTube Flickr RSS Menu ... misuse of prescription drugs can make driving a car unsafe—just like driving after drinking alcohol. Drugged ...

  11. EVALUATION OF STRUCTURAL AND VIBRATIONAL CHARACTERISTIC OF COMPOSITE DRIVE SHAFT FOR AUTOMOBILE USING FEM

    OpenAIRE

    2016-01-01

    In vehicle drive shaft is one of the most important component. It transmits torque from the engine to the differential gear of a rear wheel drive vehicle. Generally the drive shaft is made up of steel alloy but the use of conventional steel has disadvantages such as low specific stiffness and strength and high weight. Nowadays this steel drive shaft is replaced by composite material drive shaft. This advanced composite such as graphite, Kevlar, carbon, glass with suitable resin have advantage...

  12. Fault-tolerant control of electric vehicles with in-wheel motors using actuator-grouping sliding mode controllers

    Science.gov (United States)

    Li, Boyuan; Du, Haiping; Li, Weihua

    2016-05-01

    Although electric vehicles with in-wheel motors have been regarded as one of the promising vehicle architectures in recent years, the probability of in-wheel motor fault is still a crucial issue due to the system complexity and large number of control actuators. In this study, a modified sliding mode control (SMC) is applied to achieve fault-tolerant control of electric vehicles with four-wheel-independent-steering (4WIS) and four-wheel-independent-driving (4WID). Unlike in traditional SMC, in this approach the steering geometry is re-arranged according to the location of faulty wheels in the modified SMC. Three SMC control laws for longitudinal velocity control, lateral velocity control and yaw rate control are designed based on specific vehicle motion scenarios. In addition the actuator-grouping SMC method is proposed so that driving actuators are grouped and each group of actuators can be used to achieve the specific control target, which avoids the strong coupling effect between each control target. Simulation results prove that the proposed modified SMC can achieve good vehicle dynamics control performance in normal driving and large steering angle turning scenarios. In addition, the proposed actuator-grouping SMC can solve the coupling effect of different control targets and the control performance is improved.

  13. The response of a high-speed train wheel to a harmonic wheel-rail force

    Science.gov (United States)

    Sheng, Xiaozhen; Liu, Yuxia; Zhou, Xin

    2016-09-01

    The maximum speed of China's high-speed trains currently is 300km/h and expected to increase to 350-400km/h. As a wheel travels along the rail at such a high speed, it is subject to a force rotating at the same speed along its periphery. This fast moving force contains not only the axle load component, but also many components of high frequencies generated from wheel-rail interactions. Rotation of the wheel also introduces centrifugal and gyroscopic effects. How the wheel responds is fundamental to many issues, including wheel-rail contact, traction, wear and noise. In this paper, by making use of its axial symmetry, a special finite element scheme is developed for responses of a train wheel subject to a vertical and harmonic wheel-rail force. This FE scheme only requires a 2D mesh over a cross-section containing the wheel axis but includes all the effects induced by wheel rotation. Nodal displacements, as a periodic function of the cross-section angle 6, can be decomposed, using Fourier series, into a number of components at different circumferential orders. The derived FE equation is solved for each circumferential order. The sum of responses at all circumferential orders gives the actual response of the wheel.

  14. Electric drives

    CERN Document Server

    Boldea, Ion

    2005-01-01

    ENERGY CONVERSION IN ELECTRIC DRIVESElectric Drives: A DefinitionApplication Range of Electric DrivesEnergy Savings Pay Off RapidlyGlobal Energy Savings Through PEC DrivesMotor/Mechanical Load MatchMotion/Time Profile MatchLoad Dynamics and StabilityMultiquadrant OperationPerformance IndexesProblemsELECTRIC MOTORS FOR DRIVESElectric Drives: A Typical ConfigurationElectric Motors for DrivesDC Brush MotorsConventional AC MotorsPower Electronic Converter Dependent MotorsEnergy Conversion in Electric Motors/GeneratorsPOWER ELECTRONIC CONVERTERS (PECs) FOR DRIVESPower Electronic Switches (PESs)The

  15. Design and Optimization of Wheel-legged Robot:Rolling-Wolf

    Institute of Scientific and Technical Information of China (English)

    LUO Yang,LI Qimin,; LIU Zhangxing

    2014-01-01

    Though the studies of wheel-legged robots have achieved great success, the existing ones still have defects in load distribution, structure stability and carrying capacity. For overcoming these shortcomings, a new kind of wheel-legged robot(Rolling-Wolf) is designed. It is actuated by means of ball screws and sliders, and each leg forms two stable triangle structures at any moment, which is simple but has high structure stability. The positional posture model and statics model are built and used to analyze the kinematic and mechanical properties of Rolling-Wolf. Based on these two models, important indexes for evaluating its motion performance are analyzed. According to the models and indexes, all of the structure parameters which influence the motion performance of Rolling-Wolf are optimized by the method of Archive-based Micro Genetic Algorithm(AMGA) by using Isight and Matlab software. Compared to the initial values, the maximum rotation angle of the thigh is improved by 4.17%, the maximum lifting height of the wheel is improved by 65.53%, and the maximum driving forces of the thigh and calf are decreased by 25.5% and 12.58%, respectively. The conspicuous optimization results indicate that Rolling-Wolf is much more excellent. The novel wheel-leg structure of Rolling-Wolf is efficient in promoting the load distribution, structure stability and carrying capacity of wheel-legged robot and the proposed optimization method provides a new approach for structure optimization.

  16. Minisatellite Attitude Guidance Using Reaction Wheels

    Directory of Open Access Journals (Sweden)

    Ion STROE

    2015-06-01

    Full Text Available In a previous paper [2], the active torques needed for the minisatellite attitude guidance from one fixed attitude posture to another fixed attitude posture were determined using an inverse dynamics method. But when considering reaction/momentum wheels, instead of this active torques computation, the purpose is to compute the angular velocities of the three reaction wheels which ensure the minisatellite to rotate from the initial to the final attitude. This paper presents this computation of reaction wheels angular velocities using a similar inverse dynamics method based on inverting Euler’s equations of motion for a rigid body with one fixed point, written in the framework of the x-y-z sequence of rotations parameterization. For the particular case A=B not equal C of an axisymmetric minisatellite, the two computations are compared: the active torques computation versus the computation of reaction wheels angular velocities ̇x , ̇y and ̇z. An interesting observation comes out from this numerical study: if the three reaction wheels are identical (with Iw the moment of inertia of one reaction wheel with respect to its central axis, then the evolutions in time of the products between Iw and the derivatives of the reaction wheels angular velocities, i.e. ̇ , ̇ and ̇ remain the same and do not depend on the moment of inertia Iw.

  17. Preliminary Design of Reluctance Motors for Light Electric Vehicles Driving

    Directory of Open Access Journals (Sweden)

    TRIFA, V.

    2009-02-01

    Full Text Available The paper presents the aspects regarding FEM analysis of a reluctant motor for direct driving of the light electric vehicles. The reluctant motor take into study is of special construction suitable for direct drive of a light electric vehicle. It is an inverse radial reluctant motor, with a fixed stator mounted on front wheel shaft and an external toothed rotor fixed on the front wheel itself. A short presentation of preliminary design is continued with the FEM analysis in order to provide the optimal geometry of the motor and adequate windings.

  18. Design and implementation of a personal mobility of single spherical drive

    Science.gov (United States)

    Hoshino, Tasuku; Yazawa, Miki; Naganuma, Ryota; Takada, Kotaro

    2016-09-01

    This paper deals with a personal electric vehicle driven by a single spherical wheel. Using an appropriate feedback control, this driving strategy realizes dynamic stability in all directions and the vehicle can always be kept upright on the road surface of variety of slopes. It also enables immediate mobility to all directions, unlike personal vehicles of two- wheel type. The spherical wheel is driven by omnidirectional wheels as usual; however, since the number and location of wheels have huge effect on the driving performance, the authors firstly analyze kinematics of omnidirectional wheels and sphere and derive new configuration to achieve maximum power. Based on the kinematic analysis, the equation of motion of the vehicle is derived via Lagrangian formulation. The full dynamic model including kinematic constraints is then derived. Using the full model, a stabilizing controller for driving is designed based on partial feedback linearization technique. The vehicle is constructed and tested with a human driver. The proposed configuration of omnidirectional wheels, the controller design model and the control scheme are examined in practice. Results of the experiments, including going over uphill road and uneven ground, show much better driving performance than authors’ previous prototype of the similar.

  19. Medicine Wheels of the Great Plains

    Science.gov (United States)

    Vogt, David

    Medicine Wheels are unexplained aboriginal boulder configurations found primarily on hilltops and river valley vistas across the northwest Great Plains of North America. Their varied, complex designs have inspired diverse hypotheses concerning their meaning and purpose, including astronomical ones. While initial "observatory" speculations were unfounded, and quests to "decode" these structures remain unfulfilled and possibly misguided, the Medicine Wheels nevertheless represent a uniquely worthwhile case study in archaeoastronomical theory and method. In addition, emerging technologies for data acquisition and analysis pertinent to Medicine Wheels offer prospectively important new sight lines for the future of archaeoastronomy.

  20. Association between reported sleep need and sleepiness at the wheel: comparative study on French highways between 1996 and 2011

    Science.gov (United States)

    Quera-Salva, M A; Sauvagnac-Quera, R; Sagaspe, P; Taillard, J; Contrand, B; Micoulaud, J A; Lagarde, E; Barbot, F; Philip, P

    2016-01-01

    Objective To investigate the evolution over 15 years of sleep schedules, sleepiness at the wheel and driving risk among highway drivers. Methods Comparative survey including questions on usual sleep schedules and before the trip, sleepiness at the wheel, the Epworth sleepiness scale, Basic Nordic Sleep Questionnaire (BNSQ) and a travel questionnaire. Results 80% of drivers stopped by the highway patrol agreed to participate in both studies with a total of 3545 drivers in 2011 and 2196 drivers in 1996 interviewed. After standardisation based on sex, age and mean annual driving distance, drivers in 2011 reported shorter sleep time on week days (p15 indicating severe sleepiness. Conclusions Even if drivers in 2011 reported good sleep hygiene prior to a highway journey, drivers have reduced their mean weekly sleep duration over 15 years and have a higher risk of sleepiness at the wheel. Sleep hygiene for automobile drivers remains an important concept to address. PMID:28003284

  1. Dynamics and wheel's slip ratio of a wheel-legged robot in wheeled motion considering the change of height

    Science.gov (United States)

    Ding, Xilun; Li, Kejia; Xu, Kun

    2012-09-01

    The existing research on dynamics and slip ratio of wheeled mobile robot (WMR) are derived without considering the effect of height, and the existing models can not be used to analyze the dynamics performance of the robot with variable height while moving such as NOROS-II. The existing method of dynamics modeling is improved by adding the constraint equation between perpendicular displacement of body and horizontal displacement of wheel into the constraint conditions. The dynamic model of NOROS-II in wheel motion is built by the Lagrange method under nonholonomic constraints. The inverse dynamics is calculated in three different paths based on this model, and the results demonstrate that torques of hip pitching joints are inversely proportional to the height of robot. The relative error of calculated torques is less than 2% compared with that of ADAMS simulation, by which the validity of dynamic model is verified. Moreover, the relative horizontal motion between fore/hind wheels and body is produced when the height is changed, and thus the accurate slip ratio can not be obtained by the traditional equation. The improved slip ratio equations with the parameter of the vertical velocity of body are introduced for fore wheels and hind wheels respectively. Numerical simulations of slip ratios are conducted to reveal the effect of varied height on slip ratios of different wheels. The result shows that the slip ratios of fore/hind wheels become larger/smaller respectively as the height increases, and as the height is reduced, the reverse applies. The proposed research of dynamic model and slip ratio based on the robot height provides the effective method to analyze the dynamics of WMRs with varying height.

  2. The Influence of Wheel/Rail Contact Conditions on the Microstructure and Hardness of Railway Wheels

    Directory of Open Access Journals (Sweden)

    Paul Molyneux-Berry

    2014-01-01

    Full Text Available The susceptibility of railway wheels to wear and rolling contact fatigue damage is influenced by the properties of the wheel material. These are influenced by the steel composition, wheel manufacturing process, and thermal and mechanical loading during operation. The in-service properties therefore vary with depth below the surface and with position across the wheel tread. This paper discusses the stress history at the wheel/rail contact (derived from dynamic simulations and observed variations in hardness and microstructure. It is shown that the hardness of an “in-service” wheel rim varies significantly, with three distinct effects. The underlying hardness trend with depth can be related to microstructural changes during manufacturing (proeutectoid ferrite fraction and pearlite lamellae spacing. The near-surface layer exhibits plastic flow and microstructural shear, especially in regions which experience high tangential forces when curving, with consequentially higher hardness values. Between 1 mm and 7 mm depth, the wheel/rail contacts cause stresses exceeding the material yield stress, leading to work hardening, without a macroscopic change in microstructure. These changes in material properties through the depth of the wheel rim would tend to increase the likelihood of crack initiation on wheels toward the end of their life. This correlates with observations from several train fleets.

  3. The influence of wheel/rail contact conditions on the microstructure and hardness of railway wheels.

    Science.gov (United States)

    Molyneux-Berry, Paul; Davis, Claire; Bevan, Adam

    2014-01-01

    The susceptibility of railway wheels to wear and rolling contact fatigue damage is influenced by the properties of the wheel material. These are influenced by the steel composition, wheel manufacturing process, and thermal and mechanical loading during operation. The in-service properties therefore vary with depth below the surface and with position across the wheel tread. This paper discusses the stress history at the wheel/rail contact (derived from dynamic simulations) and observed variations in hardness and microstructure. It is shown that the hardness of an "in-service" wheel rim varies significantly, with three distinct effects. The underlying hardness trend with depth can be related to microstructural changes during manufacturing (proeutectoid ferrite fraction and pearlite lamellae spacing). The near-surface layer exhibits plastic flow and microstructural shear, especially in regions which experience high tangential forces when curving, with consequentially higher hardness values. Between 1 mm and 7 mm depth, the wheel/rail contacts cause stresses exceeding the material yield stress, leading to work hardening, without a macroscopic change in microstructure. These changes in material properties through the depth of the wheel rim would tend to increase the likelihood of crack initiation on wheels toward the end of their life. This correlates with observations from several train fleets.

  4. The Influence of Wheel/Rail Contact Conditions on the Microstructure and Hardness of Railway Wheels

    Science.gov (United States)

    Davis, Claire

    2014-01-01

    The susceptibility of railway wheels to wear and rolling contact fatigue damage is influenced by the properties of the wheel material. These are influenced by the steel composition, wheel manufacturing process, and thermal and mechanical loading during operation. The in-service properties therefore vary with depth below the surface and with position across the wheel tread. This paper discusses the stress history at the wheel/rail contact (derived from dynamic simulations) and observed variations in hardness and microstructure. It is shown that the hardness of an “in-service” wheel rim varies significantly, with three distinct effects. The underlying hardness trend with depth can be related to microstructural changes during manufacturing (proeutectoid ferrite fraction and pearlite lamellae spacing). The near-surface layer exhibits plastic flow and microstructural shear, especially in regions which experience high tangential forces when curving, with consequentially higher hardness values. Between 1 mm and 7 mm depth, the wheel/rail contacts cause stresses exceeding the material yield stress, leading to work hardening, without a macroscopic change in microstructure. These changes in material properties through the depth of the wheel rim would tend to increase the likelihood of crack initiation on wheels toward the end of their life. This correlates with observations from several train fleets. PMID:24526883

  5. UT Biomedical Informatics Lab (BMIL probability wheel

    Directory of Open Access Journals (Sweden)

    Sheng-Cheng Huang

    2016-01-01

    Full Text Available A probability wheel app is intended to facilitate communication between two people, an “investigator” and a “participant”, about uncertainties inherent in decision-making. Traditionally, a probability wheel is a mechanical prop with two colored slices. A user adjusts the sizes of the slices to indicate the relative value of the probabilities assigned to them. A probability wheel can improve the adjustment process and attenuate the effect of anchoring bias when it is used to estimate or communicate probabilities of outcomes. The goal of this work was to develop a mobile application of the probability wheel that is portable, easily available, and more versatile. We provide a motivating example from medical decision-making, but the tool is widely applicable for researchers in the decision sciences.

  6. Magnetic Levitation Experiments with the Electrodynamic Wheel

    Science.gov (United States)

    Cordrey, Vincent; Gutarra-Leon, Angel; Gaul, Nathan; Majewski, Walerian

    Our experiments explored inductive magnetic levitation using circular Halbach arrays with the strong variable magnetic field on the outer rim of the ring. Such a system is usually called an Electrodynamic Wheel (EDW). Rotating this wheel around a horizontal axis above a flat conducting surface should induce eddy currents in said surface through the variable magnetic flux. The eddy currents produce, in turn, their own magnetic fields which interact with the magnets of the EDW. We constructed two Electrodynamic Wheels with different diameters and demonstrated that the magnetic interactions produce both lift and drag forces on the EDW which can be used for levitation and propulsion of the EDW. The focus of our experiments is the direct measurement of lift and drag forces to compare with theoretical models using wheels of two different radii. Supported by Grants from the Virginia Academy of Science, Society of Physics Students, Virginia Community College System, and the NVCC Educational Foundation.

  7. Reaction Wheel Disturbance Model Extraction Software Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Reaction wheel mechanical noise is one of the largest sources of disturbance forcing on space-based observatories. Such noise arises from mass imbalance, bearing...

  8. Reaction Wheel with Embedded MEMS IMU Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Reaction wheels are used to stabilize satellites and to slew their orientation from object to object with precision and accuracy by varying the rotational speed of...

  9. Pile Driving

    Science.gov (United States)

    1987-01-01

    Machine-oriented structural engineering firm TERA, Inc. is engaged in a project to evaluate the reliability of offshore pile driving prediction methods to eventually predict the best pile driving technique for each new offshore oil platform. Phase I Pile driving records of 48 offshore platforms including such information as blow counts, soil composition and pertinent construction details were digitized. In Phase II, pile driving records were statistically compared with current methods of prediction. Result was development of modular software, the CRIPS80 Software Design Analyzer System, that companies can use to evaluate other prediction procedures or other data bases.

  10. Users prod FERC to encourage electricity wheeling

    Energy Technology Data Exchange (ETDEWEB)

    Hume, M.

    1985-08-19

    Some users urging the Federal Energy Regulatory Commission (FERC) to encourage or require utilities to transmit user-owned power draw parallels with the natural gas industry. Utilities contend that wheeling in this way does not necessarily improve system-wide efficiency, and can threaten reliability, although all agree that excess capacity should be moved to areas of less efficient generation or capacity need. Legislation giving FERC authority to order wheeling for customers could increase rates to remaining customers who cannot shop around.

  11. Stay Awake Behind the Wheel (A Cup of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    2016-11-10

    Being a safe driver requires complete focus on the road and the cars around you. Unfortunately, many people get behind the wheel when they’ve had a long day at work or haven’t gotten enough sleep. In this podcast, Dr. Anne Wheaton discusses the dangers of drowsy driving.  Created: 11/10/2016 by MMWR.   Date Released: 11/10/2016.

  12. High frequency vibration characteristics of electric wheel system under in-wheel motor torque ripple

    Science.gov (United States)

    Mao, Yu; Zuo, Shuguang; Wu, Xudong; Duan, Xianglei

    2017-07-01

    With the introduction of in-wheel motor, the electric wheel system encounters new vibration problems brought by motor torque ripple excitation. In order to analyze new vibration characteristics of electric wheel system, torque ripple of in-wheel motor based on motor module and vector control system is primarily analyzed, and frequency/order features of the torque ripple are discussed. Then quarter vehicle-electric wheel system (QV-EWS) dynamics model based on the rigid ring tire assumption is established and the main parameters of the model are identified according to tire free modal test. Modal characteristics of the model are further analyzed. The analysis indicates that torque excitation of in-wheel motor is prone to arouse horizontal vibration, in which in-phase rotational, anti-phase rotational and horizontal translational modes of electric wheel system mainly participate. Based on the model, vibration responses of the QV-EWS under torque ripple are simulated. The results show that unlike vertical low frequency (lower than 20 Hz) vibration excited by road roughness, broadband torque ripple will arouse horizontal high frequency (50-100 Hz) vibration of electric wheel system due to participation of the three aforementioned modes. To verify the theoretical analysis, the bench experiment of electric wheel system is conducted and vibration responses are acquired. The experiment demonstrates the high frequency vibration phenomenon of electric wheel system and the measured order features as well as main resonant frequencies agree with simulation results. Through theoretical modeling, analysis and experiments this paper reveals and explains the high frequency vibration characteristics of electric wheel system, providing references for the dynamic analysis, optimal design of QV-EWS.

  13. Study on control schemes of flexible steering system of a multi-axle all-wheel-steering robot

    Directory of Open Access Journals (Sweden)

    Pingxia Zhang

    2016-05-01

    Full Text Available It is well known that a multi-axle wheeled robot possesses larger load capability and also higher drive performance. However, its steering flexibility is degraded due to the large number of wheels. In order to solve this problem, in this article, we proposed three control schemes based on the center of rotation or the steering angles of both the first- and last-axle wheels. To release these control schemes, steering mode selection and also the left wheel’s steering angle in a specific axle are added approaching a practical application. Thereafter, the remaining wheels’ steering angles can be calculated with the Ackerman steering theorem. In order to verify the control effects, a five-axle all-wheel-steering wheeled robot has been developed with the Bluetooth wireless monitor system. Based on the newly designed robot, validation experiments are carried out, such as lateral movement, situ rotation, and multi-mode steering within a narrow space. The results indicate that the proposed design in this article can ensure a more flexible and faster movement within a narrow space. It shows large potential in obstacle avoidance compared with the conventional partial-wheel steering mode.

  14. 基于PLC控制技术和气压传动控制技术的汽车前悬架与转向轮螺纹装配设备研发%Based on PLC control technology and air pressure drive control technology of automobile front suspension and steering wheel screw assembly equipment research and development

    Institute of Scientific and Technical Information of China (English)

    陆晶晶

    2015-01-01

    在装配汽车前悬架与转向轮时需要拧紧螺纹,一旦操作不当就会出现前倾角过大的缺陷,加快车轮胎的磨损,降低小轴承及轮毂紧固螺母的使用寿命。对此,本文设计了一种基于PLC控制技术和气压传动控制技术的装配设备,能有效避免上述问题。%in the assembly of front suspension and steering wheel need to tighten the screw thread, once the defect of improper operation will appear before the Angle is too large, to speed up the car tire wear, reduce the service life of small bearings and wheel fastening nut. To this, this paper designed a kind of control technology based on PLC control technology and pneumatic transmission assembly equipment, can effectively avoid the above problems.

  15. Defining Toll Fee of Wheeling Renewable with Reference to a Gas Pipeline in Indonesia

    Science.gov (United States)

    Hakim, Amrullah

    2017-07-01

    Indonesia has a huge number of renewable energy sources (RE) however; the utilization of these is currently very low. The main challenge of power production is its alignment with consumption levels; supply should equal demand at all times. There is a strong initiative from corporations with high energy demand, compared to other sectors, to apply a renewable portfolio standard for their energy input, e.g. 15% of their energy consumption requirement must come from a renewable energy source. To support this initiative, the utilization of power wheeling will help large factories on industrial estates to source firm and steady renewables from remote sites. The wheeling renewable via PLN’s transmission line has been regulated under the Ministry Decree in 2015 however; the tariff or toll fee has not yet been defined. The potential project to apply wheeling renewable will obtain power supply from a geothermal power plant, with power demand from the scattered factories under one company. This is the concept driving the application of power wheeling in the effort to push the growth of renewable energy in Indonesia. Given that the capacity of PLN’s transmission line are normally large and less congested compared to distribution line, the wheeling renewable can accommodate the scattered factories locations which then results in the cheaper toll fee of the wheeling renewable. Defining the best toll fee is the main topic of this paper with comparison of the toll fee of the gas pipeline infrastructure in Indonesia, so that it can be applied massively to achieve COP21’s commitment.

  16. The Goal Wheel: Adapting Navajo Philosophy and the Medicine Wheel to Work with Adolescents

    Science.gov (United States)

    Garner, Holly; Bruce, Mary Alice; Stellern, John

    2011-01-01

    The purpose of this article is to describe a group counseling model that is based on the indigenous medicine wheel as well as Navajo philosophy by which to help troubled adolescents restore harmony and balance in their lives, through establishing goals and sequential steps to accomplish these goals. The authors call this model the Goal Wheel. A…

  17. Model Predictive Control considering Reachable Range of Wheels for Leg / Wheel Mobile Robots

    Science.gov (United States)

    Suzuki, Naito; Nonaka, Kenichiro; Sekiguchi, Kazuma

    2016-09-01

    Obstacle avoidance is one of the important tasks for mobile robots. In this paper, we study obstacle avoidance control for mobile robots equipped with four legs comprised of three DoF SCARA leg/wheel mechanism, which enables the robot to change its shape adapting to environments. Our previous method achieves obstacle avoidance by model predictive control (MPC) considering obstacle size and lateral wheel positions. However, this method does not ensure existence of joint angles which achieves reference wheel positions calculated by MPC. In this study, we propose a model predictive control considering reachable mobile ranges of wheels positions by combining multiple linear constraints, where each reachable mobile range is approximated as a convex trapezoid. Thus, we achieve to formulate a MPC as a quadratic problem with linear constraints for nonlinear problem of longitudinal and lateral wheel position control. By optimization of MPC, the reference wheel positions are calculated, while each joint angle is determined by inverse kinematics. Considering reachable mobile ranges explicitly, the optimal joint angles are calculated, which enables wheels to reach the reference wheel positions. We verify its advantages by comparing the proposed method with the previous method through numerical simulations.

  18. Time-frequency analysis of wheel-rail shock in the presence of wheel flat

    Directory of Open Access Journals (Sweden)

    Jianming Ding

    2014-12-01

    Full Text Available Against the deficiencies of traditional time domain and frequency domain analysis in detecting wheel-rail (W-R system hidden risks which wheel flats generate, the time-frequency characteristics of W-R shock caused by wheel flat are analyzed and the vehicle-rail dynamic model with wheel flat is investigated. The 10 degrees of freedom (DOF vehicle model is built up. 90-DOF rail model is constructed. The wheel flat excitation model is built up. The vehicle-track coupling dynamic model including wheel flat excitation is set up through nonlinear Hertzian contact theory. The vertical accelerations of axle box are calculated at different speeds and flat sizes based on the vehicle-track coupling dynamic model with wheel flat. Frequency slice wavelet transform (FSWT is employed to analyze time-frequency characteristics of axle box accelerations to detect the W-R noncontact risks s which the traditional time domain or frequency domain method does not analyze. The results show that the small flat size and high running speed lead to high frequency W-R impact. Large flat size and high running speed result in momentary loss of W-R contact, and there exist security risks between wheel and rail. The conclusion that the phase of axle box accelerations is same to W-R forces lays a theoretical foundation of monitoring W-R contact safety from axle box acceleration instead of traditional W-R force detection.

  19. Project considerations and design of systems for wheeling cogenerated power

    Energy Technology Data Exchange (ETDEWEB)

    Tessmer, R.G. Jr.; Boyle, J.R.; Fish, J.H. III; Martin, W.A.

    1994-08-01

    Wheeling electric power, the transmission of electricity not owned by an electric utility over its transmission lines, is a term not generally recognized outside the electric utility industry. Investigation of the term`s origin is intriguing. For centuries, wheel has been used to describe an entire machine, not just individual wheels within a machine. Thus we have waterwheel, spinning wheel, potter`s wheel and, for an automobile, wheels. Wheel as a verb connotes transmission or modification of forces and motion in machinery. With the advent of an understanding of electricity, use of the word wheel was extended to be transmission of electric power as well as mechanical power. Today, use of the term wheeling electric power is restricted to utility transmission of power that it doesn`t own. Cogeneration refers to simultaneous production of electric and thermal power from an energy source. This is more efficient than separate production of electricity and thermal power and, in many instances, less expensive.

  20. An autonomous miniature wheeled robot based on visual feedback control

    Institute of Scientific and Technical Information of China (English)

    CHEN Haichu

    2007-01-01

    Using two micro-motors,a novel omni-direction miniature wheeled robot is designed on the basis of the bi-corner driving principle.The robot takes advantage of the Bluetooth technology to wirelessly transmit data at a short distance.Its position and omni-direction motion are precise.A Charge Coupled Device(CCD)camera is used for measuring and for visual navigation.A control system is developed.The precision of the position is 0.5 mm,the resolution is about 0.05 mm,and the maximum velocity is about 52 mm/s.The visual navigation and control system allow the robot to navigate and track the target and to accomplish autonomous locomotion.

  1. Design of Wheeled Mobile Robot with Tri-Star Wheel as Rescue Robot

    Directory of Open Access Journals (Sweden)

    Rafiuddin Syam

    2016-05-01

    Full Text Available This study aims to design, and analyze a mobilerobot that can handle some of the obstacles, they are unevensurfaces, slopes, can also climb stairs. WMR in this study is Tristarwheel that is containing three wheels for each set. Onaverage surface only two wheels in contact with the surface, ifthere is an uneven surface or obstacle then the third wheel willrotate with the rotation center of the wheel in contact with theleading obstacle then only one wheel in contact with the surface.This study uses the C language program. Furthermore, theminimum thrust to be generated torque of the motor andtransmission is 9.56 kg. The results obtained by calculation andanalysis of DC motors used must have a torque greater than14.67 kg.cm. Minimum thrust to be generated motor torque andthe transmission is 9.56 kg. The experimental results give goodresults for robot to moving forward, backward, turn left, turnright and climbing the stairs

  2. Contributions of Determining the Forces Distribution in the Harmonic Drive

    Directory of Open Access Journals (Sweden)

    Sava Ianici

    2006-10-01

    Full Text Available The paper presents an original method for determining the forces distributions on the portant elements of the harmonic drives. This method is based on the thin wall shells theory anal on the rotating character of the distributed forces that work upon the flexible toothed wheel.

  3. Comparison of mechanical drive concepts for high power ac-traction locomotives; Vergleich mechanischer Antriebskonzepte fuer Drehstrom-Hochleistungslokomotiven

    Energy Technology Data Exchange (ETDEWEB)

    Koerner, O. [Siemens AG, Nuernberg (Germany). A und D LD T D2

    2004-11-01

    Due to the recent progress with rare earth magnets, a direct drive based on a permanent magnetic synchronous machine could be employed in high power locomotives. An unsprung and a partially suspended direct drive are compared by the criteria of complexity, costs, vertical wheel-rail forces and dynamic loads on the drive with a conventional cardan hollow shaft drive and a nose suspended drive. (orig.)

  4. Analysis of Vehicle Steering and Driving Bifurcation Characteristics

    Directory of Open Access Journals (Sweden)

    Xianbin Wang

    2015-01-01

    Full Text Available The typical method of vehicle steering bifurcation analysis is based on the nonlinear autonomous vehicle model deriving from the classic two degrees of freedom (2DOF linear vehicle model. This method usually neglects the driving effect on steering bifurcation characteristics. However, in the steering and driving combined conditions, the tyre under different driving conditions can provide different lateral force. The steering bifurcation mechanism without the driving effect is not able to fully reveal the vehicle steering and driving bifurcation characteristics. Aiming at the aforementioned problem, this paper analyzed the vehicle steering and driving bifurcation characteristics with the consideration of driving effect. Based on the 5DOF vehicle system dynamics model with the consideration of driving effect, the 7DOF autonomous system model was established. The vehicle steering and driving bifurcation dynamic characteristics were analyzed with different driving mode and driving torque. Taking the front-wheel-drive system as an example, the dynamic evolution process of steering and driving bifurcation was analyzed by phase space, system state variables, power spectral density, and Lyapunov index. The numerical recognition results of chaos were also provided. The research results show that the driving mode and driving torque have the obvious effect on steering and driving bifurcation characteristics.

  5. Assessing the influence of wheel defects of a rolling stockon railway tracks

    Directory of Open Access Journals (Sweden)

    Loktev Aleksey Alekseevich

    2015-05-01

    - slides (potholes, etc.The motion of the wheels with irregularities on the surface of the rail leads to vertical oscillation of the wheel, resulting in the forces of inertia, which is an additional load on the rail. In case of movement of the wheel with isolated roughness on the tread surface of the slide there is a strike, having a very large additional impact on the rail. Such attacks can cause kinked rails, especially in the winter months when there is increased fragility of rail steel, because of lowered temperatures. This is an abnormal phenomenon and occurs relatively rarely, at a small number of isolated irregularities on a wheel of the rolling stock. As correlations connecting the contact force and local deformation in the interaction of the wheel-rail system, we use the quasi-static Hertz’s model, linear-elastic model and two elastoplastic contact models: Alexandrov-Kadomtsev and Kil’chevsky. According to the results of Loktev’s studies ratios of the contact Hertz’s theory are quite suitable for modeling the dynamic effects of wheel and rail for speeds up to 90 km/h for engineering calculations. Since the contact surface is homogeneous and isotropic, the friction forces in the contact zone are not taken into account, the size of the pad is small compared to the dimensions of the contacting bodies and characteristic radii of curvature of the undeformed surfaces, the contacting surfaces are smooth.When train is driving, the position of the wheelset in relation to the rails varies considerably, giving rise to different combinations of the contact areas of the wheel and rail. Even assuming constant axial load the normal voltage will vary considerably because of the differences in the radii of curvature of the contacting surfaces of these zones. Thus, the proposed method allows evaluating the influence of several types of wheel defects on the condition of the rail and the prospects of its use in the upper structure of a railway track on plots with different

  6. Reaction Wheel Disturbance Model Extraction Software - RWDMES

    Science.gov (United States)

    Blaurock, Carl

    2009-01-01

    The RWDMES is a tool for modeling the disturbances imparted on spacecraft by spinning reaction wheels. Reaction wheels are usually the largest disturbance source on a precision pointing spacecraft, and can be the dominating source of pointing error. Accurate knowledge of the disturbance environment is critical to accurate prediction of the pointing performance. In the past, it has been difficult to extract an accurate wheel disturbance model since the forcing mechanisms are difficult to model physically, and the forcing amplitudes are filtered by the dynamics of the reaction wheel. RWDMES captures the wheel-induced disturbances using a hybrid physical/empirical model that is extracted directly from measured forcing data. The empirical models capture the tonal forces that occur at harmonics of the spin rate, and the broadband forces that arise from random effects. The empirical forcing functions are filtered by a physical model of the wheel structure that includes spin-rate-dependent moments (gyroscopic terms). The resulting hybrid model creates a highly accurate prediction of wheel-induced forces. It accounts for variation in disturbance frequency, as well as the shifts in structural amplification by the whirl modes, as the spin rate changes. This software provides a point-and-click environment for producing accurate models with minimal user effort. Where conventional approaches may take weeks to produce a model of variable quality, RWDMES can create a demonstrably high accuracy model in two hours. The software consists of a graphical user interface (GUI) that enables the user to specify all analysis parameters, to evaluate analysis results and to iteratively refine the model. Underlying algorithms automatically extract disturbance harmonics, initialize and tune harmonic models, and initialize and tune broadband noise models. The component steps are described in the RWDMES user s guide and include: converting time domain data to waterfall PSDs (power spectral

  7. Analysis and control of high-speed wheeled vehicles

    Science.gov (United States)

    Velenis, Efstathios

    In this work we reproduce driving techniques to mimic expert race drivers and obtain the open-loop control signals that may be used by auto-pilot agents driving autonomous ground wheeled vehicles. Race drivers operate their vehicles at the limits of the acceleration envelope. An accurate characterization of the acceleration capacity of the vehicle is required. Understanding and reproduction of such complex maneuvers also require a physics-based mathematical description of the vehicle dynamics. While most of the modeling issues of ground-vehicles/automobiles are already well established in the literature, lack of understanding of the physics associated with friction generation results in ad-hoc approaches to tire friction modeling. In this work we revisit this aspect of the overall vehicle modeling and develop a tire friction model that provides physical interpretation of the tire forces. The new model is free of those singularities at low vehicle speed and wheel angular rate that are inherent in the widely used empirical static models. In addition, the dynamic nature of the tire model proposed herein allows the study of dynamic effects such as transients and hysteresis. The trajectory-planning problem for an autonomous ground wheeled vehicle is formulated in an optimal control framework aiming to minimize the time of travel and maximize the use of the available acceleration capacity. The first approach to solve the optimal control problem is using numerical techniques. Numerical optimization allows incorporation of a vehicle model of high fidelity and generates realistic solutions. Such an optimization scheme provides an ideal platform to study the limit operation of the vehicle, which would not be possible via straightforward simulation. In this work we emphasize the importance of online applicability of the proposed methodologies. This underlines the need for optimal solutions that require little computational cost and are able to incorporate real, unpredictable

  8. Distracted Driving

    Science.gov (United States)

    ... What's this? Submit What's this? Submit Button Distracted Driving Recommend on Facebook Tweet Share Compartir Each day in the United States, over 8 people are killed and 1,161 injured in crashes ...

  9. DRIVING GREEN

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    China is promoting environmentally friendly cars to save energy and protect the environment While people enjoy the pleasure and convenience of driving, they are also creating and breathing more and more toxic

  10. Parametric study of the factors affecting wheel slip and sinkage for the Mars Exploration Rovers

    Science.gov (United States)

    Johnson, J.; Kulchitsky, A. V.; Duvoy, P.; Arvidson, R. E.; Iagnemma, K.; Senatore, C.

    2013-12-01

    In 2004 two rovers landed on Mars to conduct scientific investigations of the Martian surface in an effort to better understand its surface geology, climate, and potential to support life. During the mission, both rovers experienced events of severe rover wheel sinkage and slip in the highly variable Martian regolith. Mars Exploration Rover (MER) Opportunity experienced high wheel slip and sinkage when it attempted to cross a series of wind-blown ripples. MER rover Spirit became immobilized after breaking through a soil crust into highly deformable poorly sorted sands. Events of MER rover wheel high-sinkage and slip make mobility difficult, creating challenges for rover drive planners and increasing the risk of ending a mission early due to a lack of rover mobility. The ARTEMIS (Adams- based Rover Terramechanics and Mobility Interaction Simulator) MER rover simulation tool was developed in an effort to improve the ability to simulate rover mobility on planetary surfaces to aid planning of rover drives and to extract a rover if it becomes embedded in soil [1]. While ARTEMIS has demonstrated its ability to simulate a wide variety of rover mobility scenarios using a library of empirically based terramechanics subroutines and high-resolution digital elevation maps of Mars, it has had less success at simulating the high-sinkage, high-slip conditions that pose the highest risk to rover mobility. To improve ARTEMIS's high-slip, high-sinkage terramechanics subroutines, the COUPi discrete element method (DEM) model of MER rover wheel motion under conditions of high-sinkage and slip is being used to examine the effects of soil particle size distribution (PSD), shape, and bulk density. DEM simulations of MER wheel digging tests and the resistance forces of penetrometers in soil have demonstrated the importance of particle shape and bulk density on soil strength [2, 3]. Simulations of the densification of particle beds as functions of the spread (ratio of largest to smallest

  11. Driver`s behavior and the motion of motorized wheelchair when driving over rough surfaces; Dansa nado fuseichi sokoji no dendo kurumaisu no undo to join no kyodo

    Energy Technology Data Exchange (ETDEWEB)

    Enomoto, A.; Yokomori, M.; Yamaguchi, S. [Meijo University, Aichi (Japan)

    1997-10-01

    We analyzed about the motion of motorized wheelchairs and the driver`s behavior when passing over the small obstacles in place of the rough surface road or the gateway of house and road by experiment. The tested two type wheelchairs are the front wheel drive and the rear wheel drive. The lean angle of head and the pulse rate of driver, the feeling for stability and the yaw angle and the roll angle of the wheelchair bodies, and the deflection angle of front wheels of rear drive. 4 refs., 11 figs., 1 tab.

  12. Differential Control Strategy based on an Equal Slip Rate for an All-wheel Electricdrive Underground Articulated Dumping Truck

    Directory of Open Access Journals (Sweden)

    Jin Chun

    2014-09-01

    Full Text Available A differential control strategy based on equal slip rates is introduced to improve the steering stability of an all-wheelelectric-drive underground articulated dumping truck. Steering kinematic and dynamic models of the truck are derived to describe the movement relationship and force of the driving wheels. In consideration of the difficulty of obtaining the absolute velocity for an all-wheel-drive truck, an acceleration sensor was set on a test truck, and a kalman filter was applied to obtain the actual value for the truck body. Simulation results for an equal-slip control strategy were compared with experimental results for an equal-torque control strategy. In the simulation, the four-wheel slip rate was 0.08 and the steering system of the truck was stable. The results verify that the equal-slip control strategy makes better use of the ground adhesion coefficient, is able to reasonably distribute drive power, notably reduces tire wear, and improves the use of driving power.

  13. Steady state modeling of desiccant wheels

    DEFF Research Database (Denmark)

    Bellemo, Lorenzo; Elmegaard, Brian; Kærn, Martin Ryhl

    2014-01-01

    Desiccant wheels are rotary desiccant dehumidifiers used in air conditioning and drying applications. The modeling of simultaneous heat and mass transfer in these components is crucial for estimating their performances, as well as for simulating and optimizing their implementation in complete sys...... be taken into account in a future version of the model. More experimental data have to be gathered to implement eventual missing phenomena and validate the model for all input parameters....... systems. A steady state two-dimensional model is formulated and implemented aiming to obtain good accuracy and short computational times. Comparison with experimental data from the literature shows that the model reproduces the physical behavior of desiccant wheels. Mass diffusion in the desiccant should......Desiccant wheels are rotary desiccant dehumidifiers used in air conditioning and drying applications. The modeling of simultaneous heat and mass transfer in these components is crucial for estimating their performances, as well as for simulating and optimizing their implementation in complete...

  14. High-spin Mn wheels.

    Science.gov (United States)

    Manoli, Maria; Prescimone, Alessandro; Bagai, Rashmi; Mishra, Abhudaya; Murugesu, Muralee; Parsons, Simon; Wernsdorfer, Wolfgang; Christou, George; Brechin, Euan K

    2007-08-20

    The syntheses, structures, and magnetic properties of the complexes [MnIV4MnIII10MnII2O2(OCH3)12(tmp)8(O2CCH3)10].3Et2O (1.3Et2O), [MnIV2MnIII18MnII2O6(OCH3)14(O2CCH3)16(tmp)8(HIm)2].2CH3OH (2.2CH3OH), and [MnIV2MnIII18MnII2O6(OCH3)14(O2CCH3)16(Br-mp)8(HIm)2].2C6H14.5CH3OH (3.2C6H14.5CH3OH) are reported. The unusual wheel-like complexes were prepared by the treatment of [Mn3O(O2CCH3)6(HIm)3](O2CCH3) (HIm = imidazole) with 1,1,1-tris-(hydroxymethyl)propane (H3tmp) (1 and 2) or 2-(bromomethyl)-2-(hydroxymethyl)-1,3-propanediol (Br-mpH3) (3) in the presence of sodium methoxide (NaOCH3, 2, and 3) in CH3OH. Complex 1.3Et2O crystallizes in the triclinic space group P, while complexes 2.2CH3OH and 3.2C6H14.5CH3OH crystallize in the orthorhombic space group Pbca. Direct current magnetic susceptibility data, collected for 1-3 in the respective 1.8-300 K and 0.1-7 T temperature and magnetic-field ranges, afford spin ground-state values of S = 14 +/- 1 for complex 1 and S = 9 +/- 1 for complexes 2 and 3. Alternating current susceptibility measurements performed on all three complexes in the 1.8-10 K temperature range in a 3.5 G oscillating field at frequencies between 50 and 1000 Hz reveal out-of-phase chi"M signals below approximately 3 K. Single-crystal hysteresis loop and relaxation measurements confirm single-molecule magnetism behavior.

  15. Optically trapped and driven paddle-wheel

    Science.gov (United States)

    Asavei, Theodor; Nieminen, Timo A.; Loke, Vincent L. Y.; Stilgoe, Alexander B.; Bowman, Richard; Preece, Daryl; Padgett, Miles J.; Heckenberg, Norman R.; Rubinsztein-Dunlop, Halina

    2013-06-01

    We demonstrate the control and rotation of an optically trapped object, an optical paddle-wheel, with the rotation direction normal to the beam axis. This is in contrast to the usual situation where the rotation is about the beam axis. The paddle-wheel can be optically driven and moved to any position in the field of view of the microscope, which can be of interest for various biological applications where controlled application of a fluid flow is needed in a particular location and in a specific direction. This is of particular interest in signal transduction studies in cells, especially when a cell is flat and spread out on a surface.

  16. Wheeled foot quadruped robot HITAN-I

    Institute of Scientific and Technical Information of China (English)

    Wang Pengfei; Sun Lining

    2006-01-01

    In view of the robot running environment, the structure of wheeled foot and quadruped are adopted in this robot system, which combines the priorities of both wheeled robot and legged robot. Based on CAN bus, the two-class robot control system using multiple controllers and drivers is constructed. At the same time, serial inverse kinematics of swaying leg and parallel inverse kinematics of supporting legs are analyzed independently. The forward gait and turning gait are planned and experiment image is given at last.

  17. GEAR WHEELS THE PROCESSED BY ELECTRICAL EROSION

    Directory of Open Access Journals (Sweden)

    MARCEL S.POPA

    2015-12-01

    Full Text Available For low tooth loads and low peripheral speeds between 0.3 and 2 m / s are chosen based alloys and steels, gray cast iron. In industry are preferable ferrous alloys: bronze, brass and aluminum alloys, and where speeds and demands are low gears are made of sheet steel or alloys. Wheel group required less include some hand-operated mechanisms, such as jacks, some trolls. These wheels are larger and they are made of alloy steel, semi-hard and sometimes gray cast iron FC250, FC300.

  18. [Fracture of the diaphyseal radius during Cyr wheel practice - an uncommon injury of wheel gymnastics].

    Science.gov (United States)

    Kauther, M D; Rummel, S; Hussmann, B; Lendemans, S; Nast-Kolb, D; Wedemeyer, C

    2011-12-01

    The cyr wheel is a modified gymnastic wheel with only one ring that can lead to extreme forces on the gymnast. We report on a distal radius shaft fracture (AO 22 A 2.1) and a fracture of the styloid process of the ulna that occurred after holding on to a slipping Cyr wheel and exposition to high pressure on the lower arm. The fracture was fixed by screws and a plate. © Georg Thieme Verlag KG Stuttgart · New York.

  19. Measuring wheel/rail contact stresses using ultrasound

    OpenAIRE

    Marhsall, M.B.; Lewis, R.; Dwyer-Joyce, R.S.; Olofsson, O.; Bjorklund, S

    2004-01-01

    The investigation of contact area and pressure distribution in a wheel/rail contact is essential information required in fatigue and wear calculations to determine design life, regrinding requirements, and maintenance schedules. The aim of this work was to use ultrasound to non-destructively determine wheel/rail contact pressures. Three different contacts were investigated those resulting from; un-used, sand damaged, and worn wheel/rail specimens. \\ud \\ud A wheel/rail interface behaves like a...

  20. On a New Method for Evaluation of Wheel Climb Derailment

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In the paper, a new derailment index λ for evaluation of wheel climb derailment is proposed which is based on primary suspension forces. It is easy to apply because of its minimum criterion characteristic and can also be applied to explain the reason why wheel climb derailments are almost always accompanied by some wheel unloadings.

  1. Rolling Friction on a Wheeled Laboratory Cart

    Science.gov (United States)

    Mungan, Carl E.

    2012-01-01

    A simple model is developed that predicts the coefficient of rolling friction for an undriven laboratory cart on a track that is approximately independent of the mass loaded onto the cart and of the angle of inclination of the track. The model includes both deformation of the wheels/track and frictional torque at the axles/bearings. The concept of…

  2. Investigating Functions with a Ferris Wheel

    Science.gov (United States)

    Johnson, Heather Lynn; Hornbein, Peter; Azeem, Sumbal

    2016-01-01

    The authors provide a dynamic Ferris wheel computer activity that teachers can use as an instructional tool to help students investigate functions. They use a student's work to illustrate how students can use relationships between quantities to further their thinking about functions.

  3. Steerable wheel structure for ground vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Frye, N.V.

    1988-09-27

    This patent describes a ground vehicle having a fore-and-aft body including transversely spaced apart, right and left, fore-and-aft supports: steerable wheel structure comprising transverse axle means disposed between the supports and having right and left end portions respectively adjacent to the right and left supports, a wheel journaled on the axle means intermediate the supports on a transverse horizontal axis, right and left carriers respectively on the right and left supports, each including a fixed element mounted fixedly on the associated support and a movable member arranged for selective fore-and-aft movement relative to the support and relative to each other, right and left connecting means connecting the right and left movable members respectively to the right and left end portions of the axle means for effecting steering of the wheel as one carrier moves forward and the other moves simultaneously rearwardly, and vice versa, at least one of the members at each side of the body being constructed to accommodate fore-and-aft swinging of the axle means during steering of the wheel, and means for moving the movable members simultaneously, one forwardly and the other rearwardly.

  4. Examination of a failed fifth wheel coupling

    CSIR Research Space (South Africa)

    Fernandes, PJL

    1998-03-01

    Full Text Available Examination of a fifth wheel coupling which had failed in service showed that it had been modified and that the operating handle had been moved from its original design position. This modification completely eliminated the safety device designed...

  5. Some Armchair Worries about Wheeled Behavior

    NARCIS (Netherlands)

    Keijzer, F.A.

    1998-01-01

    Autonomous agents research aims to understand adaptive behavior by building models that exhibit such behavior. In this paper, I describe some theoretical worries about the tendency to simplify the sensory-motor control of these behaving models as much as possible. Wheeled robots provide a good examp

  6. Some Armchair Worries about Wheeled Behavior

    NARCIS (Netherlands)

    Keijzer, F.A.

    1998-01-01

    Autonomous agents research aims to understand adaptive behavior by building models that exhibit such behavior. In this paper, I describe some theoretical worries about the tendency to simplify the sensory-motor control of these behaving models as much as possible. Wheeled robots provide a good examp

  7. Experiments on a Tail-wheel Shimmy

    Science.gov (United States)

    Harling, R; Dietz, O

    1954-01-01

    Model tests on the "running belt" and tests with a full-scale tail wheel were made on a rotating drum as well as on a runway in order to investigate the causes of the undesirable shimmy phenomena frequently occurring on airplane tail wheels, and the means of avoiding them. The small model (scale 1:10) permitted simulation of the mass, moments of inertia, and fuselage stiffness of the airplane and determination of their influence on the shimmy, whereas by means of the larger model with pneumatic tires (scale 1:2) more accurate investigations were made on the tail wheel itself. The results of drum and road tests show good agreement with one another and with model values. Detailed investigations were made regarding the dependence of the shimmy tendency on trail, rolling speed, load, size of tires, ground friction,and inclination of the swivel axis; furthermore, regarding the influence of devices with restoring effect on the tail wheel, and the friction damping required for prevention of shimmy. Finally observations from slow-motion pictures are reported and conclusions drawn concerning the influence of tire deformation.

  8. 77 FR 67400 - RG Steel Wheeling, LLC, a Division of RG Steel, LLC, Doing Business as Wheeling Corrugating...

    Science.gov (United States)

    2012-11-09

    ... Employment and Training Administration RG Steel Wheeling, LLC, a Division of RG Steel, LLC, Doing Business as..., 2012, applicable to workers of RG Steel Wheeling, LLC, a division of RG Steel, LLC, doing business as... RG Steel, LLC, doing business as Wheeling Corrugating Company, Beech Bottom, West Virginia,...

  9. A dynamic wheel-rail impact analysis of railway track under wheel flat by finite element analysis

    Science.gov (United States)

    Bian, Jian; Gu, Yuantong; Murray, Martin Howard

    2013-06-01

    Wheel-rail interaction is one of the most important research topics in railway engineering. It involves track impact response, track vibration and track safety. Track structure failures caused by wheel-rail impact forces can lead to significant economic loss for track owners through damage to rails and to the sleepers beneath. Wheel-rail impact forces occur because of imperfections in the wheels or rails such as wheel flats, irregular wheel profiles, rail corrugations and differences in the heights of rails connected at a welded joint. A wheel flat can cause a large dynamic impact force as well as a forced vibration with a high frequency, which can cause damage to the track structure. In the present work, a three-dimensional finite element (FE) model for the impact analysis induced by the wheel flat is developed by the use of the FE analysis (FEA) software package ANSYS and validated by another validated simulation. The effect of wheel flats on impact forces is thoroughly investigated. It is found that the presence of a wheel flat will significantly increase the dynamic impact force on both rail and sleeper. The impact force will monotonically increase with the size of wheel flats. The relationships between the impact force and the wheel flat size are explored from this FEA and they are important for track engineers to improve their understanding of the design and maintenance of the track system.

  10. Wheel traffic effect on air-filled porosity and air permeability in a soil catena across the wheel rut

    DEFF Research Database (Denmark)

    Berisso, Feto Esimo; Schjønning, Per; Lamandé, Mathieu

    The impact of wheel traffic on soil physical properties is usually quantified by randomly collecting soil cores at specific depths below the wheeled surface. However, modeling studies as well as few measurements indicated a non-uniform stress distribution in a catena across the wheel rut, which m...

  11. Death Drive

    OpenAIRE

    Stühler, Rebekka Hellstrøm

    2012-01-01

    The aim of this project is to investigate why the Freudian term Death Drive is not acknowledged in modern psychological therapy. On basis of psychoanalytical theory and through a literary analysis, the project will present a discussion of the significance and presence of the term within these practises.

  12. Bright Soil Churned by Spirit's Sol 1861 Drive

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Spirit drove 22.7 meters (74 feet) toward the southwest on the 1,861st Martian day, or sol, of Spirit's mission on Mars (March 28, 2009). After the drive, the rover took this image with its front hazard-avoidance camera, looking back at the tracks from the drive. As usual since losing the use of its right-front wheel in 2006, Spirit drove backwards. The immobile right-front wheel churned up a long stripe of bright soil during this drive. Where Spirit has found such bright soil in the past, subsequent analysis of the composition found concentrations of sulfur or silica that testified to past action of water at the site. When members of the rover team saw the large quantity of bright soil exposed by the Sol 1861 drive, they quickly laid plans to investigate the composition with Spirit's alpha particle X-ray spectrometer. The Sol 1861 drive took the rover past the northwest corner of the low plateau called 'Home Plate,' making progress on a route around the western side of Home Plate. The edge of Home Plate forms the horizon on the right side of this image. Husband Hill is on the horizon on the left side. For scale, the parallel rover wheel tracks are about 1 meter (40 inches) apart. The rover's hazard-avoidance cameras take 'fisheye' wide-angle images.

  13. A magnetic bearing momentum wheel for high pointing accuracy and vibration sensitive space applications

    Science.gov (United States)

    Bichler, U. J.

    The paper describes a magnetic bearing momentum wheel (MW-X) theoretically and experimentally with attention given to its low-noise application to spacecraft attitude-control systems. The MW-X gyroscopic actuator comprises a rotor, emergency bearings, a locking mechanisms, and a drive motor, and Vernier gimballing is employed so that the rotor and the momentum vector can be tilted actively with about one degree. The MW-X utilizes a suspension-control system for noise attenuation and active vibration suppression to reduce noise from the sensor surface. The actively controlled magnetic bearing wheels are shown to provide active damping of flexible structures by means of fully controllable translational bearing forces. The MW-X devices are of interest for applications to optical communications links, space telescopes, and earth-observation satellites with high resolutions.

  14. Research on Stability Control Based on the Wheel Speed Difference for the AT Vehicles

    Directory of Open Access Journals (Sweden)

    Hui Jin

    2015-01-01

    Full Text Available This paper utilizes a linear two-degree-of-freedom vehicle model to calculate the nominal value of the vehicle’s nondrive-wheel speed difference and investigates methods of estimating the yaw acceleration and sideslip angular speed. A vehicular dynamic stability control system utilizing this nondrive-wheel speed difference is then developed, which can effectively improve a vehicle’s dynamic stability at a very low cost. Vehicle cornering processes on roads of different frictions and with different vehicle speeds are explored via simulation, with speed control being applied when vehicle speed is high enough to make the vehicle unstable. Driving simulator tests of vehicle cornering capacity on roads of different friction coefficients are also conducted.

  15. Experimental Studies of Neural Network Control for One-Wheel Mobile Robot

    Directory of Open Access Journals (Sweden)

    P. K. Kim

    2012-01-01

    Full Text Available This paper presents development and control of a disc-typed one-wheel mobile robot, called GYROBO. Several models of the one-wheel mobile robot are designed, developed, and controlled. The current version of GYROBO is successfully balanced and controlled to follow the straight line. GYROBO has three actuators to balance and move. Two actuators are used for balancing control by virtue of gyro effect and one actuator for driving movements. Since the space is limited and weight balance is an important factor for the successful balancing control, careful mechanical design is considered. To compensate for uncertainties in robot dynamics, a neural network is added to the nonmodel-based PD-controlled system. The reference compensation technique (RCT is used for the neural network controller to help GYROBO to improve balancing and tracking performances. Experimental studies of a self-balancing task and a line tracking task are conducted to demonstrate the control performances of GYROBO.

  16. Design of Wheeled Mobile Robot with Tri-Star Wheel as Rescue Robot

    Directory of Open Access Journals (Sweden)

    Rafiuddin Syam

    2014-10-01

    Full Text Available This study aims to design, and analyze a mobile robot that can handle some of the obstacles, they are uneven surfaces, slopes, can also climb stairs. WMR in this study is Tristar wheel that is containing three wheels for each set. On average surface only two wheels in contact with the surface, if there is an uneven surface or obstacle then the third wheel will rotate with the rotation center of the wheel in contact with the leading obstacle then only one wheel in contact with the surface. This study uses the C language program. Furthermore, the minimum thrust to be generated torque of the motor and transmission is 9.56 kg. The results obtained by calculation and analysis of DC motors used must have a torque greater than 14.67 kg.cm. Minimum thrust to be generated motor torque and the transmission is 9.56 kg. The experimental results give good results for robot to moving forward, backward, turn left, turn right and climbing the stairs.

  17. Designing a Miniature Wheel Arrangement for Mobile Robot Platforms

    CERN Document Server

    Kayani, Saheeb Ahmed

    2011-01-01

    In this research report details of design of a miniature wheel arrangement are presented. This miniature wheel arrangement is essentially a direction control mechanism intended for use on a mobile robot platform or base. The design is a specific one employing a stepper motor as actuator and as described can only be used on a certain type of wheeled robots. However as a basic steering control element, more than one of these miniature wheel arrangements can be grouped together to implement more elaborate and intelligent direction control schemes on varying configurations of wheeled mobile robot platforms.

  18. Wheel pose measurement based on cross structure light

    Science.gov (United States)

    Zhao, Qiancheng; Ding, Xun; Wang, Xian; Zhao, Yafeng

    2016-01-01

    It's necessary for automobile to detect and adjust four-wheel alignment parameters regularly, due to the significant effect on improving stability, enhancing security and reducing tire wear of automobiles. In order to measure the parameters that determined by relative position and posture of four wheels to the automobile cab, this paper proposes a method which applies monocular vision of linear structure light to wheel pose measurement. Firstly, space coordinates of feature point cloud are calculated out from the principle of structured light. Then, an algorithm is designed to determine the normal vector of wheel tangent plane and measure the wheel pose. Finally, actual experiments that by evaluation of adjusted wheel angle measurement are carried out to verify the system accuracy. The corresponding studies can be applied in designing and developing 3D four-wheel alignment system that based on structured light.

  19. Reliability of Heart Rate Variability Analysis by Using Electrocardiogram Recorded Unrestrainedly from an Automobile Steering-Wheel

    Science.gov (United States)

    Osaka, Motohisa; Murata, Hiroshige; Tateoka, Katsuhiko; Katoh, Takao

    2007-07-01

    Some cases of traffic accidents are assumed to be due to the occurrences of cardiac events during driving, which are thought to be induced by imbalance of autonomic nervous activities. These can be measured by analyzing heart rate variability. Therefore, we developed a new system of steering-wheel electrocardiogram with a soft-ware to remove noises. We compared the trends of sympathetic and parasympathetic nerve activities measured from the steering-wheel electrocardiograms with those recorded simultaneously from chest leads. For each parameter of instantaneous heart rate, low- or high-frequency component of heart rate variability in all the cases, the trend from the steering-wheel electrocardiogram resembled that from the chest-lead electrocardiogram. In 3 of 7 subjects, the trend of LF/HF showed a strong relationship between the steering-wheel electrocardiogram and the chest-lead electrocardiogram. Our system will open doors to a new strategy to keep a driver out of a risk by notifying it while driving.

  20. Comparison between normal and special chain-drive toothing

    Energy Technology Data Exchange (ETDEWEB)

    Dolipski, M.

    1985-12-01

    A comparison of these two types of tooth arrangements on chain drives with round-link chains comes out clearly in favour of the special toothing. The article describes the advantages of this type of toothing. A proposal is made to use the special tooth arrangement in the construction of drive pocket wheels. Such a move would prevent the disastrous effects of links becoming jammed in the pockets during running-in and would consequently improve the service life of both chain and drive sprocket.

  1. Assessment of Lateral Driving Stability of Automobiles Passing by the Pylon Zone under Cross Wind

    OpenAIRE

    Dalei Wang; Airong Chen

    2012-01-01

    In order to explore the reason of lateral instability of automobile passing by the pylon zone of cablesupported bridge under cross wind, a new evaluation method of lateral driving stability of automobile considering alternative cross wind is established based on multi-objective driving stability criteria and subjective assessment. Typical driving control process and dynamic response of automobile passing by the pylon zone is given by numerical simulation based on steering wheel fixed-control ...

  2. Effectiveness of a Driving Intervention on Safe Community Mobility for Returning Combat Veterans

    Science.gov (United States)

    2016-05-01

    driving errors, strategies including problem identification , verifying driving errors via the simulator playback function, and establishing...information systems, and an automotive control environment. The “live” controls of the CDS-250 simulator are its steering wheel with active force...feedback, automatic transmission, turn signals, gas and brake pedals. The readouts of the CDS-250 driving simulator include a speedometer and a high

  3. Research on Vibration Characteristics Between Human Body and Seat, Steering Wheel, and Pedals (effects of Seat Position on Ride Comfort)

    Science.gov (United States)

    NISHIYAMA, S.; UESUGI, N.; TAKESHIMA, T.; KANO, Y.; TOGII, H.

    2000-09-01

    Experimental results are presented of the vibrational characteristics of the automotive subsystem comprising the human body, seat, steering wheel and pedals. The magnitude of the vibrations transferred to a driver from the seat, steering wheel and pedals have been measured with both sinusoidal and random excitations in the vertical direction at frequencies up to 20 Hz. Measurement points were located on the surface of the head, chest, hip, thigh, shin, upper arm and lower arm. Eleven subjects were used to investigate the effect of some variable factors, such as arm angle, that may affect human dynamic behavior. It was found that arm angle in driving posture has a substantial influence on the dynamic behavior of the human body while driving. Some results are presented in the form of parametric graphs and tables. The results are useful for improving ride comfort, maneuverability and safety.

  4. 3MK1420外沟磨床砂轮修整器改造%Improvement of grinding wheel dresser for 3MK1420 outer groove grinding machine

    Institute of Scientific and Technical Information of China (English)

    姚淑敏

    2013-01-01

    Aiming at the problem of chain drive in grinding wheel dresser for 3MK1420 outer groove grinding machine, chain drive is superseded by steel belt drive so as to improve the drive stability and the dressing quality.%  针对3MK1420外沟磨床砂轮修整器链条传动存在的问题,采用钢带传动取代链条传动,提高了传动平稳性及砂轮修整质量。

  5. Improved Squeaky Wheel Optimisation for Driver Scheduling

    CERN Document Server

    Aickelin, Uwe; Li, Jingpeng

    2008-01-01

    This paper presents a technique called Improved Squeaky Wheel Optimisation for driver scheduling problems. It improves the original Squeaky Wheel Optimisations effectiveness and execution speed by incorporating two additional steps of Selection and Mutation which implement evolution within a single solution. In the ISWO, a cycle of Analysis-Selection-Mutation-Prioritization-Construction continues until stopping conditions are reached. The Analysis step first computes the fitness of a current solution to identify troublesome components. The Selection step then discards these troublesome components probabilistically by using the fitness measure, and the Mutation step follows to further discard a small number of components at random. After the above steps, an input solution becomes partial and thus the resulting partial solution needs to be repaired. The repair is carried out by using the Prioritization step to first produce priorities that determine an order by which the following Construction step then schedul...

  6. Phenomena of Foamed Concrete under Rolling of Aircraft Wheels

    Science.gov (United States)

    Jiang, Chun-shui; Yao, Hong-yu; Xiao, Xian-bo; Kong, Xiang-jun; Shi, Ya-jie

    2014-04-01

    Engineered Material Arresting System (EMAS) is an effective technique to reduce hazards associated with aircraft overrunning runway. In order to ascertain phenomena of the foamed concrete used for EMAS under rolling of aircraft wheel, a specially designed experimental setup was built which employed Boeing 737 aircraft wheels bearing actual vertical loads to roll through the foamed concrete. A number of experiments were conducted upon this setup. It is discovered that the wheel rolls the concrete in a pure rolling manner and crushes the concrete downwards, instead of crushing it forward, as long as the concrete is not higher than the wheel axle. The concrete is compressed into powder in-situ by the wheel and then is brought to bottom of the wheel. The powder under the wheel is loose and thus is not able to sustain wheel braking. It is also found that after being rolled by the wheel the concrete exhibits either of two states, i.e. either 'crushed through' whole thickness of the concrete or 'crushed halfway', depending on combination of strength of the concrete, thickness of the concrete, vertical load the wheel carries, tire dimension and tire pressure. A new EMAS design concept is developed that if an EMAS design results in the 'crushed through' state for the main gears while the 'crushed halfway' state for the nose gear, the arresting bed would be optimal to accommodate the large difference in strength between the nose gear and the main gear of an aircraft.

  7. Braking, Wheeled Vehicles. Test Operations Procedure (TOP)

    Science.gov (United States)

    2008-05-20

    shields removed, inspect the internal brake components, perform a camshaft rotation test and record the measurement obtained. c. If with non-removable...preceding 24 months, perform a camshaft rotation test and record the measurement. (2) When proof of wheel removal is not provided, remove brake drum(s...adjustment. Reject the vehicle if: • The adjustment is not within the manufacturer’s specifications. 15. Brake Camshafts Procedure: With

  8. A magneto-electric quantum wheel

    CERN Document Server

    Feigel, Alexander

    2009-01-01

    Here we show that self-propulsion in quantum vacuum may be achieved by rotating or aggregating magneto-electric nano-particles. The back-action follows from changes in momentum of electro-magnetic zero-point fluctuations, generated in magneto-electric materials. This effect may provide new tools for investigation of the quantum nature of our world. It might also serve in the future as a "quantum wheel" to correct satellite orientation in space.

  9. Coatings for gear wheels; Beschichtungen fuer Zahnraeder

    Energy Technology Data Exchange (ETDEWEB)

    Petrik, M.; Wittorf, R.; Thomsen, H. [Fraunhofer-Institut fuer Schicht- und Oberflaechentechnik, IST, Braunschweig (Germany). Transferzentrum Tribologie; Kaestner, P. [Technische Univ. Braunschweig (Germany). Inst. fuer Oberflaechentechnik; Kropp, J.P. [Technische Univ. Braunschweig (Germany). Inst. fuer Konstruktionstechnik

    2008-08-15

    In order to optimize the goal, steel gear wheels regarding load-carrying capacity and wear, thin film coatings were tested. Different coating systems were examined numerically with the software ELASTICA {sup registered} for their suitability. The characteristics of the coating systems were determined dependent on the material, its surface treatment as well as the diameters of relevant rolling partners. Differences were made between macroscopic rolling contacts between the teeth profiles and microscopic contacts with surface roughness and abrasion particles. First the four best suitable coating systems were deposited on simplified rollers and examined under different conditions. Two coating systems were determined, which show special suitability for the coating of the gear wheels. The first system is an a:C-H coating with an CrN interlayer. The second system is an a:C-H coating with an CrN interlayer on a plasma-nitrided substrat (Duplex-process). In order to protect the coatings on the teeth, their involute profile was provided with a tip relief. As gear wheel materials 16MnCr5, 42CrMo4 as well as the special steel ETG {sup registered} 88 were used. Two kinds of flow fats were used as lubricants and additional the unlubricated operation was examined. The gear wheels were tested at three different speeds on a test machine especially built for it. The testing routine was carried out in so-called power-stages. Each stage means a defined number of contacts and a certain Hertzian stress on the teeth profiles. With each stage the Hertzian stress was increased. The end of operation time is the beginning of cavitation pitting. The test results showed that in particular with the steel 16MnCr5 and 42CrMo4 the used Duplex-systems leads to considerable increases of the load-carrying capacity of the tooth flanks and the wear resistance. (orig.)

  10. Effect of sleep deprivation on driving safety in housestaff.

    Science.gov (United States)

    Marcus, C L; Loughlin, G M

    1996-12-01

    Sleep deprivation is known to affect driving safety. Housestaff (HS) are routinely sleep-deprived when on call. We hypothesized that this would affect their driving. We therefore administered questionnaires regarding driving to 70 pediatric HS, who were on call every fourth night, and to 85 faculty members (FAC), who were rarely disturbed at night. HS were questioned about events during their residency, and FAC were questioned about events during the preceding three years. There was an 87% response rate for each group. HS slept 2.7 +/- 0.9 (SD) hours when on call vs 7.2 +/- 0.8 hours when not on call (p wheel; 90% of these events occurred post-call. In contrast, only 13% of FAC had fallen asleep at the wheel (p moving violations vs. 15 for FAC and were involved in 20 motor vehicle accidents vs. 11 for FAC. One traffic citation clearly resulted from HS falling asleep at the wheel vs. none for FAC. We conclude that HS frequently fall asleep when driving post-call. We speculate that current HS work schedules may place some HS at risk for injury to themselves and others. Further study, using prospectively objective measures is indicated.

  11. Rotating target wheel for the FMA

    Energy Technology Data Exchange (ETDEWEB)

    Back, B.B.; Davids, C.N.; Falout, J. [and others

    1995-08-01

    In anticipation of high intensity beams that will be available from the PII-ECR source injector to ATLAS, a new rotating target wheel was developed for the sliding seal chamber at the FMA. The wheel is 9 inch in diameter and contains up to ten targets. The rotation of the wheel is achieved by a DC motor, a ferrofluidic feedthrough, and a gear mechanism that allows both target rotation and changing the target angle relative to the beam. The nominal rotation speed is 1000 RPM, although higher speeds can be achieved if necessary. The assembly is equipped with an absolute encoder which is read out via a newly developed CAMAC module. This module provides the following main functions: (1) a TTL signal to be used for sweeping the beam when a target frame is about to pass through the beam, (2) a read-out of the target position that can be included in the data event structure, (3) programmable set points for the beam-off signal. The system is presently being tested and will be used in experiments scheduled for March 1995.

  12. Teen Drinking and Driving – What You Need to Know PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2012-10-02

    This 60 second public service announcement is based on the October 2012 CDC Vital Signs report. It’s illegal and dangerous for teens to drink any alcohol and then drive. Still, one in ten high school teens drank and got behind the wheel in 2011. A parent-teen driving agreement is a good way for parents to help keep young drivers safe behind the wheel.  Created: 10/2/2012 by Centers for Disease Control and Prevention (CDC).   Date Released: 10/2/2012.

  13. Teen Drinking and Driving – What You Need to Know

    Centers for Disease Control (CDC) Podcasts

    2012-10-02

    This podcast is based on the October 2012 CDC Vital Signs report. It’s illegal and dangerous for teens to drink any alcohol and then drive. Still, one in ten high school teens drank and got behind the wheel in 2011. A parent-teen driving agreement is a good way for parents to help keep young drivers safe behind the wheel.  Created: 10/2/2012 by Centers for Disease Control and Prevention (CDC).   Date Released: 10/2/2012.

  14. Rotating target wheel system for super-heavy element production at ATLAS

    CERN Document Server

    Greene, J P; Falout, J; Janssens, R V F

    2004-01-01

    A new scattering chamber housing a large diameter rotating target wheel has been designed and constructed in front of the Fragment Mass Analyzer (FMA) for the production of very heavy nuclei (Z greater than 100) using beams from the Argonne Tandem Linear Accelerator System (ATLAS). In addition to the target and drive system, the chamber is extensively instrumented in order to monitor target performance and deterioration. Capabilities also exist to install rotating entrance and exit windows for gas cooling of the target within the scattering chamber. The design and initial tests are described.

  15. A portable wheel tester for tyre-road friction and rolling resistance determination

    Science.gov (United States)

    Pytka, J.; Budzyński, P.; Tarkowski, P.; Piaskowski, M.

    2016-09-01

    The paper describes theory of operation, design and construction as well as results from primarily experiments with a portable wheel tester that has been developed by the authors as a device for on-site determination of tyre-road braking/driving friction and rolling resistance. The paper includes schematics, drawings, descriptions as well as graphical results form early tests with the presented device. It is expected that the tester can be useful in road accident reconstruction applications as well as in vehicle dynamics research.

  16. Integrated control strategies for railway vehicles with independently-driven wheel motors

    Institute of Scientific and Technical Information of China (English)

    Jinzhi FENG; Jun LI; R. M. Goodall

    2008-01-01

    This paper studies the development of inte-grated control strategies for railway vehicles with inde-pendently-driven wheel motors. First, a non-linear vehicle dynamic model and motor drive strategy are pre-sented, which are followed by an investigation of the inte-grated control of stabilization, steering, and traction for the vehicle. Meanwhile a reformulated Kalman filter is developed and applied to estimate the required feedback by the control system. Finally, the effectiveness and prac-ticality of the proposed integrated controller are examined and assessed by real-time simulation based on host-target computer technology provided by Matlab/Simulink.

  17. Problems of locomotive wheel wear in fleet replacement

    Directory of Open Access Journals (Sweden)

    L.P. Lingaytis

    2013-08-01

    Full Text Available Purpose. To conduct a research and find out the causes of defects appearing on the wheel thread of freight locomotives 2М62 and SIEMENS ER20CF. Methodology. To find the ways to solve this problem comparing the locomotive designs and their operating conditions. Findings. After examining the nature of the wheel wear the main difference was found: in locomotives of the 2M62 line wears the wheel flange, and in the locomotives SIEMENS ER20CF – the tread surface. After installation on the 2M62 locomotive the lubrication system of flanges their wear rate significantly decreased. On the new freight locomotives SIEMENS ER20CF the flange lubrication systems of the wheel set have been already installed at the factory, however the wheel thread is wearing. As for locomotives 2M62, and on locomotives SIEMENS ER20CF most wear profile skating wheels of the first wheel set. On both locomotive lines the 2М62 and the SIEMENS ER20CF the tread profile of the first wheel set most of all is subject to the wear. After reaching the 170 000 km run, the tread surface of some wheels begins to crumble. There was a suspicion that the reason for crumb formation of the wheel surface may be insufficient or excessive wheel hardness or its chemical composition. In order to confirm or deny this suspicion the following studies were conducted: the examination of the rim surface, the study of the wheel metal hardness and the document analysis of the wheel production and their comparison with the results of wheel hardness measurement. Practical value. The technical condition of locomotives is one of the bases of safety and reliability of the rolling stock. The reduction of the wheel wear significantly reduces the operating costs of railway transport. After study completion it was found that there was no evidence to suggest that the ratio of the wheel-rail hardness could be the cause of the wheel surface crumbling.

  18. E-drive with electrically controlled differential; E-Antrieb mit elektrisch geregeltem Differenzial

    Energy Technology Data Exchange (ETDEWEB)

    Smetana, Tomas; Biermann, Thorsten [Schaeffler Technologies GmbH und Co. KG, Herzogenaurach (Germany); Rohe, Marco [AFT Atlas Fahrzeugtechnik GmbH, Werdohl (Germany); Heinrich, Wolfgang [IDAM, Suhl (Germany)

    2011-10-15

    Schaeffler is presenting an all-wheel drive electric vehicle named 'Active eDrive'. The name is intended principally to convey innovation and the USP of the drive system: an electric differential with a torque vectoring function. The system combines the final drive with intelligent transverse torque distribution which, when used on axles, enables the distribution of torque over the longitudinal axis of the vehicle. The final drive can be integrated in both electric and hybrid vehicles with or without a range extender capability. The authors first explain the mechanical requirements and then describe the electrical systems that are intended to fulfill these. (orig.)

  19. The colour wheels of art, perception, science and physiology

    Science.gov (United States)

    Harkness, Nick

    2006-06-01

    Colour is not the domain of any one discipline be it art, philosophy, psychology or science. Each discipline has its own colour wheel and this presentation examines the origins and philosophies behind the colour circles of Art, Perception, Science and Physiology (after image) with reference to Aristotle, Robert Boyle, Leonardo da Vinci, Goethe, Ewald Hering and Albert Munsell. The paper analyses and discusses the differences between the four colour wheels using the Natural Colour System® notation as the reference for hue (the position of colours within each of the colour wheels). Examination of the colour wheels shows the dominance of blue in the wheels of art, science and physiology particularly at the expense of green. This paper does not consider the three-dimensionality of colour space its goal was to review the hue of a colour with regard to its position on the respective colour wheels.

  20. OPTIMIZATION OF HEATING OF GEAR WHEEL USING NUMERICAL MODELING

    Directory of Open Access Journals (Sweden)

    Sona Benesova

    2013-05-01

    Full Text Available Successful heat treating and carburizing of gear wheels for wind turbine gear boxes requires that plastic deformation in the wheel is minimized. Numerical modeling using the DEFORM software was aimed at exploring the effects of the base, on which the gear wheel rests during heating, on the heating process. Homogeneous heating was assumed. It was found that the base heats up more quickly than the workpiece. It is the consequence of the base's shape and volume. As a result, the base expands and slides against the wheel, predominantly at the first heating stage. Later on, it prevents the gear wheel from expanding, causing plastic deformation in the wheel. The findings were used for designing new heating schedules to minimize these undesirable interactions and to reduce the plastic deformation to a negligible magnitude. In addition, this paper presents an example of a practical use of numerical modeling in the DEFORM software.

  1. OPTIMIZATION OF HEATING OF GEAR WHEEL USING NUMERICAL MODELING

    Directory of Open Access Journals (Sweden)

    Soňa Benešová

    2013-09-01

    Full Text Available Successful heat treating and carburizing of gear wheels for wind turbine gear boxes requires that plastic deformation in the wheel is minimized. Numerical modeling using the DEFORM software was aimed at exploring the effects of the base, on which the gear wheel rests during heating, on the heating process. Homogeneous heating was assumed. It was found that the base heats up more quickly than the workpiece. It is the consequence of the base's shape and volume. As a result, the base expands and slides against the wheel, predominantly at the first heating stage. Later on, it prevents the gear wheel from expanding, causing plastic deformation in the wheel. The findings were used for designing new heating schedules to minimize these undesirable interactions and to reduce the plastic deformation to a negligible magnitude. In addition, this paper presents an example of a practical use of numerical modeling in the DEFORM software.

  2. Explore, Synthesize, and Repeat: Unraveling Complex Water Management Issues through the Stakeholder Engagement Wheel

    Directory of Open Access Journals (Sweden)

    Kelly E. Mott Lacroix

    2016-03-01

    Full Text Available Effective stakeholder engagement is fundamental to water management, yet there are as many approaches to consultation as there are efforts. This paper provides an evaluation of, and lessons learned from three water management engagement processes, and uses this assessment to offer a framework for stakeholder engagement. The Stakeholder Engagement Wheel framework is centered on a bridging organization that ensures that the process continues to move forward, and a steering committee that guides and changes activities according to stakeholder interests and concerns. Around the Stakeholder Engagement Wheel are four steps designed to examine iteratively the water management issue driving the engagement process and expand the sphere of interests involved. Many engagement processes have limited effectiveness because of: (1 paucity of time; (2 complexity of water resources management; (3 difficulty of engaging diverse stakeholders; and (4 lack of methods for engagement that are centered on empowerment, equity, trust, and learning. In this study, we have encountered all four of these issues and have addressed all but the first through a deliberate, iterative, and flexible approach. By cycling through activities and actions as proposed in the Stakeholder Engagement Wheel, we can build a community of practitioners with the nuanced and shared understanding needed for cohesive action and robust decisions in the face our considerable challenges.

  3. Robust cascade control for the horizontal motion of a vehicle with single-wheel actuators

    Science.gov (United States)

    Moseberg, Jan-Erik; Roppenecker, Günter

    2015-12-01

    The article presents a cascade control for the horizontal motion of a vehicle with single-wheel actuators. The outer control loop for the longitudinal and lateral accelerations and the yaw rate ensures a desired vehicle motion. By a combination of state feedback control and observer-based disturbance feedforward the inner control loop robustly stabilises the rotating and steering motions of the wheels in spite of unknown frictions between tyres and ground. Since the three degrees of freedom of the horizontal motion are affected by eight tyre forces, the vehicle considered is an over-actuated system. Thus additional control objectives can be realised besides the desired motion trajectory as, for example, a maximum in driving safety. The corresponding analytical tyre force allocation also guarantees real-time capability because of its relatively low computational effort. Provided suitable fault detection and isolation are available, the proposed cascade control has the potential of fault-tolerance, because the force allocation is adaptable. Another benefit results from the modular control structure, because it allows a stepwise implementation. Besides, it only requires a small number of measurements for control purposes. These measurements are the rotational speeds and steering angles of the wheels, the longitudinal and lateral acceleration and the yaw rate of the vehicle.

  4. Force Analysis of Geneva Wheel and Face Cam Used In Automat

    Directory of Open Access Journals (Sweden)

    Madhoo G

    2014-06-01

    Full Text Available Glazerol Automat is a dedicated machine used in the Insulator pre assembly line. This automat is driven using single motor for different operations. Here the focus is on two main parts they are Geneva wheel and Face cam which are used for their respective operations. Geneva Wheel is used to index the drum which consists of 96 spindles. Due to this Geneva mechanism each of the spindles will hold the ceramic body when the drum is being indexed. Due to which there is a force which is generated in the Geneva wheel in maximum and minimum position. Face cam which is used while indexing the work piece carrier There are 2 tangential forces which are acting, one at the indexing side and the other at the driving side /cam side. The effective resultant force which is acting on the face cam while indexing work piece carrier is calculated. And these forces are analyzed using ansys and their respective Von Mises stresses and displacement plots are obtained for both the conditions based on boundary and loading conditions.

  5. Solar wheel chair; Solar kurumaisu (iryokei no tachiba kara no kokoromi)

    Energy Technology Data Exchange (ETDEWEB)

    Okabe, K. [Gunma Prefectural College of Health Sciences, Gunma (Japan)

    1996-10-27

    Physically handicapped people due to accidents for example have been increasing yearly in number with the increase of the aged, spread of cars, and change in the living environment. Therefore, participation in society by such people as called the weak is indispensable. Under the circumstances, as a means of their participation, a wheel chair as a moving aid was examined from the viewpoint of medical treatment and classified into three categories as follows: (1) for the use of the aged who are healthy but leg muscles are weak, (2) for the use of the invalid incapable of moving a part of the body and (3) for the use in sports by people who are disabled in the lower half of the body but healthy otherwise. In other words, prototypes were made for three kinds of solar wheel chair, for the aged, for the invalid and for sport use by the disabled, with a field test performed for each prototype. The wheel chairs were exhibited in the school, used in welfare facilities and driven by a disabled person who participated in 100km marathon. The users` opinions were favorable stating they were able to drive by themselves the new vehicle utilizing the clean energy and to move around by their own free will. 6 refs., 5 figs.

  6. CAF, a generalised conicity criteria for the wheel rail contact

    OpenAIRE

    AYASSE, JB; Chollet, H; FLEURET, JS; Leveque, E.

    2002-01-01

    With several examples, this paper will show why the most significant parameter to be considered at the wheel rail contact is the angle of the tangent plane, function of the transversal relative displacement between wheel and rail (contact angle function, CAF). This parameter is the key point of INRETS methodology for static and dynamic studies of the wheel rail contact in non linear conditions. A practical example is given with switch blades.

  7. Experimental characterization of wheel-rail contact patch evolution

    OpenAIRE

    Marshall, M.B.; Lewis, R.; Dwyer-Joyce, R.S.; Olofsson, U.; Björklund, S.

    2006-01-01

    The contact area and pressure distribution in a wheel/rail contact is essential information required in any fatigue or wear calculations to determine design life, re-grinding, and maintenance schedules. As wheel or rail wear or surface damage takes place the contact patch size and shape will change. This leads to a redistribution of the contact stresses. The aim of this work was to use ultrasound to nondestructively quantify the stress distribution in new, worn, and damaged wheel-rail contact...

  8. Evaluation of the effect of pregabalin on simulated driving ability using a driving simulator in healthy male volunteers

    Directory of Open Access Journals (Sweden)

    Tujii T

    2014-01-01

    Full Text Available Tomoaki Tujii, Win Thiri Kyaw, Hirotaka Iwaki, Noriko Nishikawa, Masahiro Nagai, Madoka Kubo, Masahiro Nomoto Department of Neurology and Clinical Pharmacology, Ehime University Graduate School of Medicine, Tohon Ehime, Japan Abstract: Pregabalin, a novel agent for treating partial epilepsy and peripheral neuropathic and central pain, was studied for its effect on driving performance in healthy volunteers. Sixteen healthy male volunteers who drove regularly were enrolled in a double-blind, parallel-group, placebo-controlled study assessing the effect of pregabalin on driving performance. Subjects received an oral dose of pregabalin 75 mg or placebo, and a second dose 12 hours later. A driving simulator was used to test simple and complicated braking reaction time, and simple and complicated steering-wheel techniques before the first dose, and 1 hour and 3 hours after the second dose of pregabalin or placebo. The effect of training during the driving test on the driving performance of each group was also evaluated. There were no statistically significant differences in driving performance between the pregabalin and the placebo groups. However, the pregabalin group showed no significant improvement in steering-wheel skills with training, whereas the placebo group showed a significant (P<0.05 improvement with training. In this study using a driving simulator, pregabalin did not impair driving performance but mildly reduced the training effects of driving experiments. Although pregabalin caused sleepiness, it had no severe effect on driving ability after a second dose of 75 mg after the initial introduction of pregabalin. Keywords: pregabalin, driving, volunteers

  9. Neutron Scattering Collimation Wheel Instrument for Imaging Research

    Science.gov (United States)

    Van Every, E.; Deyhim, A.

    2016-09-01

    The design of a state-of-the-art selector wheel instrument to support the area of neutron imaging research (neutron radiography/ tomography) is discussed. The selector wheel is installed on the DINGO Radiography instrument at the Bragg Institute HB2 beamline at ANSTO in Sidney Aus. The selector wheel consists of a single axis drum filled with a wax/steel shielding mixture and six square cutouts for neutron optics and a larger solid shielding sector to act as a shutter. This paper focuses on the details of design and shielding of the selector wheel.

  10. Frictional Heat-Induced Phase Transformation on Train Wheel Surface

    Institute of Scientific and Technical Information of China (English)

    SU Hang; PAN Tao; LI Li; YANG Cai-fu; CUI Yin-hui; JI Huai-zhong

    2008-01-01

    By combining thermomechanical coupling finite element analysis with the characteristics of phase transformation [continuous cooling transformation (CCT) curve],the thermal fatigue behavior of train wheel steel under high speed and heavy load conditions was analyzed.The influence of different materials on the formation of the phase transformation zone of the wheel tread was discussed.The result showed that the peak temperature of wheel/track friction zone could be higher than the austenitizing temperature for braking.The depth of the austenitized region could reach a point of 0.9 mm beneath the wheel tread surface.The supercooled austenite is transformed to a hard and brittle martensite layer during the following rapid cooling process,which may lead to cracking and then spalling on the wheel tread surface.The decrease in carbon contents of the train wheel steel helps inhibit the formation of martensite by increasing the austenitizing temperature of the train wheel steel.When the carbon contents decrease from 0.7% to 0.4%,the Ac3 of the wheel steel is increased by 45 ℃,and the thickness of the martensite layer is decreased by 30%,which is helpful in reducing the thermal cycling fatigue of the train wheel tread such as spalling.

  11. Novel drive mechanism for in-tube micro robots

    Institute of Scientific and Technical Information of China (English)

    CHEN Yangzhi; XING Guangquan; PENG Xuefei; LIU Wenguang; YAO Huaping

    2007-01-01

    The volume of an in-tube micro robot is small and its interior space is very limited. However, conventional transmission methods are unfit to drive in-tube micro robots. A novel micro drive mechanism called the micro-elastic- meshing-wheel is presented in this paper. It can be used for transmitting power and locomotion between two shafts, which are upright and cross in a micro space. The mechanical model of the novel drive mechanism is built, and the maximal trans- mission force is deduced. Then, sufficient experiments are carried out to test maximal transmission force produced by the novel drive mechanism. The calculation and experiment results show that the novel drive mechanism can transmit sufficient power to in-tube micro robots.

  12. Influence of wheel configuration on wheelchair basketball performance : Wheel stiffness, tyre type and tyre orientation

    NARCIS (Netherlands)

    Mason, B. S.; Lemstra, M.; van der Woude, L. H. V.; Vegter, R.; Goosey-Tolfrey, V. L.

    The aim of the current investigation was to explore the lateral stiffness of different sports wheelchair wheels available to athletes in 'new' and 'used' conditions and to determine the effect of (a) stiffness, (b) tyre type (clincher vs. tubular) and (c) tyre orientation on the physiological and

  13. Wheel-slip Control Method for Seeking Maximum Value of Tangential Force between Wheel and Rail

    Science.gov (United States)

    Kondo, Keiichiro; Yasuoka, Ikuo; Yamazaki, Osamu; Toda, Shinichi; Nakazawa, Yosuke

    A method for reducing motor torque in proportion to wheel slip is applied to an inverter-driven electric locomotive. The motor torque at wheel-slip speed is less than the torque at the maximum tangential force or the adhesion force. A novel anti-slip control method for seeking the maximum value of the tangential force between the wheel and rail is proposed in this paper. The characteristics of the proposed method are analyzed theoretically to design the torque reduction ratio and the rate of change of the pattern between the wheel-slip speed and motor current. In addition, experimental tests are also carried out to verify that the use of the proposed method increases the traction force of an electric locomotive driven by induction motors and inverters. The experimental test results obtained by using the proposed control method are compared with the experimental results obtained by using a conventional control method. The averaged operational current when using the proposed control method is 10% more than that when using the conventional control method.

  14. Influence of wheel configuration on wheelchair basketball performance : Wheel stiffness, tyre type and tyre orientation

    NARCIS (Netherlands)

    Mason, B. S.; Lemstra, M.; van der Woude, L. H. V.; Vegter, R.; Goosey-Tolfrey, V. L.

    2015-01-01

    The aim of the current investigation was to explore the lateral stiffness of different sports wheelchair wheels available to athletes in 'new' and 'used' conditions and to determine the effect of (a) stiffness, (b) tyre type (clincher vs. tubular) and (c) tyre orientation on the physiological and bi

  15. Strangulation--Suicide at the wheel.

    Science.gov (United States)

    Madea, Burkhard; Schmidt, Peter; Kernbach-Wighton, Gerhard; Doberentz, Elke

    2015-11-01

    In cases of suicide at the wheel mostly velocity is used to cause death by a single occupant vehicle crash against a fixed roadside object or collision with other vehicles. A further well known mode of death is e.g. carbon monoxide poisoning. In the recent years several cases of vehicle assisted ligature strangulation resulting even in decapitation have been reported. However, cars are also used in rare cases just as places for a suicide by hanging or ligature strangulation. Not only forensic pathologists but also police officers have to be aware of this rare type of suicide to avoid unnecessary investigations.

  16. Design and Analysis of a Novel Speed-Changing Wheel Hub with an Integrated Electric Motor for Electric Bicycles

    Directory of Open Access Journals (Sweden)

    Yi-Chang Wu

    2013-01-01

    Full Text Available The aim of this paper is to present an innovative electromechanical device which integrates a brushless DC (BLDC hub motor with a speed-changing wheel hub stored on the rear wheel of an electric bicycle. It combines a power source and a speed-changing mechanism to simultaneously provide functions of power generation and transmission for electric bicycles. As part of the proposed integrated device, the wheel hub consists of a basic planetary gear train providing three forward speeds including a low-speed gear, a direct drive, and a high-speed gear. Each gear is manually controlled by the shift control sleeve to selectively engage or disengage four pawl-and-ratchet clutches based on its clutching sequence table. The number of gear teeth of each gear element of the wheel hub is synthesized. The BLDC hub motor is an exterior-rotor-type permanent-magnet synchronous motor. Two-dimensional finite-element analysis (FEA software is employed to facilitate the motor design and performance analysis. An analysis of the power transmission path at each gear is provided to verify the validity of the proposed design. The results of this work are beneficial to the embodiment, design, and development of novel electromechanical devices for the power and transmission systems of electric bicycles.

  17. A Wheeled Mobile Device for Deployment of Surface and Subsurface Instruments and for Subsurface Sampling on Planets

    Science.gov (United States)

    Richter, L.; Bernasconi, M.; Haapanala, S.; Steiner, R.; Coste, P.

    2003-04-01

    shifting the center-of-mass, should the vehicle fall on its side. All wheels and the two folding levers are individually driven by brushless DC motors located inside a thermal enclosure in the vehicle cab. Except for the actuators and drive mechanisms, the enclosure houses a central electronics unit which also provides pre-processing of payload data. For the power supply and communications, a tether link to the lander is used, allowing a maximum range of some 20 m. As to the tether type, a flexible printed circuit was chosen which allows efficient packaging of the tether on board the vehicle. The wheel design was based on theoretical and experimental studies on tractive performance of small wheels on planetary soils being one of the subjects of the MIDD activity, involving a dedicated soil channel at DLR. As a result, the vehicle wheels were chosen to be rigid while featuring a wire mesh running surface and chevron-shaped grousers. Mass of a flight unit is projected to be around 2.9 kg, excluding the vehicle payload. The principal design philosophy for MIDD has been: conservative design with sufficient margins (i.e., provision of thermal enclosure for instruments); early component development and realistic environmental testing (mechanism functional testing in Thermal Vacuum; dust sealing test with mechanisms operating in simulated airborne dust environment of Mars).

  18. First Wheel of the Hadronic EndCap Calorimeter Completed

    CERN Document Server

    Oram, C.J.

    2002-01-01

    With the LAr calorimeters well advanced in module production, the attention is turning to Batiment 180 where the calorimeter modules are formed into complete detectors and inserted into their respective cryostats. For the Hadronic End Cap (HEC) Group the task in B180 is to assemble the wheels, rotate them into their final orientation, and put them onto the cradle in front of the End Cap Cryostat. These tasks have been completed for the first HEC wheel in the B180 End Cap Clean Room. Given that this wheel weighs 70 tons the group is very relieved to have established that these gymnastics with the wheel proceed in a routine fashion. To assemble a wheel we take modules that have already been cold tested, do the final electrical testing and locate them onto the HEC wheel assembly table. Four wheels are required in total, each consisting of 32 modules. Wheel assembly is done in the horizontal position, creating a doughnut-like object sitting on the HEC table. The first picture shows the last module being added ...

  19. Experiments on the resistance of airplane wheels and radiators

    Science.gov (United States)

    1924-01-01

    Experiments were made on the resistance of four airplane wheels of different sizes and coverings and two Lamblin radiators. The results show the important influence of the wheel coverings. The closing of a shutter, which was fitted to one of the radiators, considerably lessened the resistance.

  20. Considering the Influence of Prerequisite Performance on Wheel Spinning

    Science.gov (United States)

    Wan, Hao; Beck, Joseph Barbosa

    2015-01-01

    The phenomenon of wheel spinning refers to students attempting to solve problems on a particular skill, but becoming stuck due to an inability to learn the skill. Past research has found that students who do not master a skill quickly tend not to master it at all. One question is why do students wheel spin? A plausible hypothesis is that students…

  1. Model-based analysis and simulation of regenerative heat wheel

    DEFF Research Database (Denmark)

    Wu, Zhuang; Melnik, Roderick V. N.; Borup, F.

    2006-01-01

    of mathematical models for the thermal analysis of the fluid and wheel matrix. The effect of heat conduction in the direction of the fluid flow is taken into account and the influence of variations in rotating speed of the wheel as well as other characteristics (ambient temperature, airflow and geometric size...

  2. 76 FR 29265 - Certain Steel Wheels From China

    Science.gov (United States)

    2011-05-20

    ... Register of April 5, 2011 (76 FR 18781). The conference was held in Washington, DC, on April 20, 2011, and... COMMISSION Certain Steel Wheels From China Determinations On the basis of the record \\1\\ developed in the... threatened with material injury by reason of imports from China of certain steel wheels, provided for...

  3. 77 FR 27249 - Certain Steel Wheels From China

    Science.gov (United States)

    2012-05-09

    ..., and by publishing the notice in the Federal Register on November 23, 2011 (76 FR 72441). The hearing... COMMISSION Certain Steel Wheels From China Determinations On the basis of the record \\1\\ developed in the... of imports of certain steel wheels from China, provided for in subheading 8708.70 of the...

  4. Procedure and applications of combined wheel/rail roughness measurement

    NARCIS (Netherlands)

    Dittrich, M.G.

    2009-01-01

    Wheel-rail roughness is known to be the main excitation source of railway rolling noise. Besides the already standardised method for direct roughness measurement, it is also possible to measure combined wheel-rail roughness from vertical railhead vibration during a train pass-by. This is a different

  5. The Development of Wheels for the Lunar Roving Vehicle

    Science.gov (United States)

    Asnani, Vivake; Delap, Damon; Creager, Colin

    2009-01-01

    The Lunar Roving Vehicle (LRV) was developed for NASA s Apollo program so astronauts could cover a greater range on the lunar surface, carry more science instruments, and return more soil and rock samples than by foot. Because of the unique lunar environment, the creation of flexible wheels was the most challenging and time consuming aspect of the LRV development. Wheels developed for previous lunar systems were not sufficient for use with this manned vehicle; therefore, several new designs were created and tested. Based on criteria set by NASA, the choices were narrowed down to two: the wire mesh wheel developed by General Motors (GM), and the hoop spring wheel developed by the Bendix Corporation. Each of these underwent intensive mechanical, material, and terramechanical analyses, and in the end, the wire mesh wheel was chosen for the LRV. Though the wire mesh wheel was determined to be the best choice for its particular application, it may be insufficient towards achieving the objectives of future lunar missions that could require higher tractive capability, increased weight capacity, or extended life. Therefore lessons learned from the original LRV wheel development and suggestions for future Moon wheel projects are offered.

  6. Prediction of aspects of soil-wheel systems.

    NARCIS (Netherlands)

    Koolen, A.J.; Lerink, P.; Kurstjens, D.A.G.; Akker, van den J.J.H.; Arts, W.B.M.

    1992-01-01

    A simple formula is given which predicts maximum stress-depth relationships under wheels from vertical wheel load and the tyre inflation pressure. Predictions were compared with stress measurements at a depth of 30 cm under a wide range of vehicles. Stress measurements at a depth of 15 cm showed tha

  7. Simulation of Intelligent Single Wheel Mobile Robot

    Directory of Open Access Journals (Sweden)

    Maki K. Rashid

    2008-11-01

    Full Text Available Stabilization of a single wheel mobile robot attracted researcher attentions in robotic area. However, the budget requirements for building experimental setups capable in investigating isolated parameters and implementing others encouraged the development of new simulation methods and techniques that beat such limitations. In this work we have developed a simulation platform for testing different control tactics to stabilize a single wheel mobile robot. The graphic representation of the robot, the dynamic solution, and, the control scheme are all integrated on common computer platform using Visual Basic. Simulation indicates that we can control such robot without knowing the detail of it's internal structure or dynamics behaviour just by looking at it and using manual operation tactics. Twenty five rules are extracted and implemented using Takagi-Sugeno's fuzzy controller with significant achievement in controlling robot motion during the dynamic simulation. The resulted data from the successful implementation of the fuzzy model are used to utilize and train a neurofuzzy controller using ANFIS scheme to produce further improvement in robot performance

  8. New Small Wheel Technical Design Report

    CERN Document Server

    Kawamoto, T; Pontecorvo, L; Dubbert, J; Mikenberg, G; Iengo, P; Dallapiccola, C; Amelung, C; Levinson, L; Richter, R; Lellouch, D; CERN. Geneva. The LHC experiments Committee; LHCC

    2013-01-01

    In order to benefit from the expected high luminosity performance that will be provided by the Phase-I upgraded LHC, the first station of the ATLAS muon end-cap system (Small Wheel,SW) will need to be replaced. The New Small Wheel (NSW) will have to operate in a high background radiation region (up to 15 kHz=cm2) while reconstructing muon tracks with high precision, as well as furnishing information for the Level-1 trigger. These performance criteria are demanding. In particular, the precision reconstruction of tracks for offline analysis requires a spatial resolution of about 100microns, and the Level-1 trigger track segments have to be reconstructed online with an angular resolution of approximately 1mrad. The NSW will have two chamber technologies, one primarily devoted to the Level-1 trigger function (small-strip Thin Gap Chambers, sTGC) and one dedicated to precision tracking (Micromegas detectors, MM). The sTGC are primarily deployed for triggering given their single bunch crossing identification capabi...

  9. Camber Angle Inspection for Vehicle Wheel Alignments

    Science.gov (United States)

    Young, Jieh-Shian; Hsu, Hong-Yi; Chuang, Chih-Yuan

    2017-01-01

    This paper introduces an alternative approach to the camber angle measurement for vehicle wheel alignment. Instead of current commercial approaches that apply computation vision techniques, this study aims at realizing a micro-control-unit (MCU)-based camber inspection system with a 3-axis accelerometer. We analyze the precision of the inspection system for the axis misalignments of the accelerometer. The results show that the axes of the accelerometer can be aligned to the axes of the camber inspection system imperfectly. The calibrations that can amend these axis misalignments between the camber inspection system and the accelerometer are also originally proposed since misalignments will usually happen in fabrications of the inspection systems. During camber angle measurements, the x-axis or z-axis of the camber inspection system and the wheel need not be perfectly aligned in the proposed approach. We accomplished two typical authentic camber angle measurements. The results show that the proposed approach is applicable with a precision of ±0.015∘ and therefore facilitates the camber measurement process without downgrading the precision by employing an appropriate 3-axis accelerometer. In addition, the measured results of camber angles can be transmitted via the medium such as RS232, Bluetooth, and Wi-Fi. PMID:28165365

  10. Camber Angle Inspection for Vehicle Wheel Alignments

    Directory of Open Access Journals (Sweden)

    Jieh-Shian Young

    2017-02-01

    Full Text Available This paper introduces an alternative approach to the camber angle measurement for vehicle wheel alignment. Instead of current commercial approaches that apply computation vision techniques, this study aims at realizing a micro-control-unit (MCU-based camber inspection system with a 3-axis accelerometer. We analyze the precision of the inspection system for the axis misalignments of the accelerometer. The results show that the axes of the accelerometer can be aligned to the axes of the camber inspection system imperfectly. The calibrations that can amend these axis misalignments between the camber inspection system and the accelerometer are also originally proposed since misalignments will usually happen in fabrications of the inspection systems. During camber angle measurements, the x-axis or z-axis of the camber inspection system and the wheel need not be perfectly aligned in the proposed approach. We accomplished two typical authentic camber angle measurements. The results show that the proposed approach is applicable with a precision of ± 0.015 ∘ and therefore facilitates the camber measurement process without downgrading the precision by employing an appropriate 3-axis accelerometer. In addition, the measured results of camber angles can be transmitted via the medium such as RS232, Bluetooth, and Wi-Fi.

  11. Design and Fem Analysis of Car Alloy Wheel

    Directory of Open Access Journals (Sweden)

    Venkatesh. K

    2016-12-01

    Full Text Available The requirements for improved stiffness, reliability, fatigue life and increased efficiency involves challenges of developing innovative design solutions. The present work mainly focus on the design of car alloy wheel, where the analytical and FEM analysis approach was implemented to analyze baseline design. Initially static analysis was performed to obtain total deformation, strain and the stress of car alloy wheel. Three Dimensional model was created using CATIA and FE software ANSYS was used for discretization and analysis to obtain expected solution. The results were obtained through linear static analysis in terms of Total deformation while Minimum principal stress, Max Principal stress were found to be nearly equal for both 6 arms wheel and 4 arms wheel and 22.16 % of reduction in weight was observed and hence overall weight of the car alloy wheel was optimized.

  12. ONLINE GRINDING WHEEL WEAR COMPENSATION BY IMAGE BASED MEASURING TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    WAN Daping; HU Dejin; WU Qi; ZHANG Yonghong

    2006-01-01

    Automatic compensation of grinding wheel wear in dry grinding is accomplished by an image based online measurement method. A kind of PC-based charge-coupled device image recognition system is schemed out, which detects the topography changes of the grinding wheel surface. Profile data, which corresponds to the wear and the topography, is measured by using a digital image processing method. The grinding wheel wear is evaluated by analyzing the position deviation of the grinding wheel edge. The online wear compensation is achieved according to the measure results. The precise detection and automatic compensation system is integrated into an open structure CNC curve grinding machine. A practical application is carried out to fulfil the precision curve grinding. The experimental results confirm the benefits of the proposed techniques, and the online detection accuracy is less than 5 μm. The grinding machine provides higher precision according to the in-process grinding wheel error compensation.

  13. A Traction Control Strategy with an Efficiency Model in a Distributed Driving Electric Vehicle

    Science.gov (United States)

    Lin, Cheng

    2014-01-01

    Both active safety and fuel economy are important issues for vehicles. This paper focuses on a traction control strategy with an efficiency model in a distributed driving electric vehicle. In emergency situation, a sliding mode control algorithm was employed to achieve antislip control through keeping the wheels' slip ratios below 20%. For general longitudinal driving cases, an efficiency model aiming at improving the fuel economy was built through an offline optimization stream within the two-dimensional design space composed of the acceleration pedal signal and the vehicle speed. The sliding mode control strategy for the joint roads and the efficiency model for the typical drive cycles were simulated. Simulation results show that the proposed driving control approach has the potential to apply to different road surfaces. It keeps the wheels' slip ratios within the stable zone and improves the fuel economy on the premise of tracking the driver's intention. PMID:25197697

  14. On Car Wheel Alignment and Adjustment Techniques to Detect%浅谈汽车四轮定位检测与调整技术

    Institute of Scientific and Technical Information of China (English)

    代孝红

    2014-01-01

    In normal driving car wheel alignment plays a very important role. Automotive wheel alignment parameters for testing and adjusting, not only to ensure the normal running of the car, but also to extend tire life, while saving fuel. Focus on the automotive wheel alignment detection methods and adjustment techniques.%四轮定位对汽车的正常行驶起着十分重要的作用。对汽车四轮定位参数进行检测和调整,不仅能确保汽车的正常行驶,还能延长轮胎的使用寿命,同时节省油耗。重点研究了汽车四轮定位的检测方法和调整技术。

  15. Installation of the first of the big wheels of the ATLAS muon spectrometer, a thin gap chamber (TGC) wheel

    CERN Multimedia

    Claudia Marcelloni

    2006-01-01

    The muon spectrometer will include four big moving wheels at each end, each measuring 25 metres in diameter. Of the eight wheels in total, six will be composed of thin gap chambers for the muon trigger system and the other two will consist of monitored drift tubes (MDTs) to measure the position of the muons

  16. How to measure driving ability under the influence of alcohol and drugs, and why

    NARCIS (Netherlands)

    Brookhuis, K.A.

    1998-01-01

    Car driving performance is easily disrupted as a consequence of the use of alcohol and/or (il)licit drugs. Various aspects of vehicle handling have been used to measure drug effects, including: lateral position deviation, steering wheel handling, speed control, use of pedals and headway control. Alc

  17. Teen Drinking and Driving: A Dangerous Mix. CDC Vitalsigns[TM

    Science.gov (United States)

    Centers for Disease Control and Prevention, 2012

    2012-01-01

    The percentage of teens in high school who drink and drive has decreased by more than half since 1991, but more can be done. Nearly one million high school teens drank alcohol and got behind the wheel in 2011. Teen drivers are 3 times more likely than more experienced drivers to be in a fatal crash. Drinking any alcohol greatly increases this risk…

  18. 直驱轮毂式永磁无刷电动机气隙磁场解析数值法分析%Analytical-Numerical Method Air-Gap Magnetic Field Analysis on the Direct-Drive Wheel-Hub Permanent Magnet Brushless Motor

    Institute of Scientific and Technical Information of China (English)

    李春江; 卢铁斌; 章跃进

    2011-01-01

    Air-gap magnetic field of the direct-drive outer rotor surface-mount permanent magnet fractional slot brushless motor was analyzed with the analytical-numerical method.The domain of the magnetic field was divided into air-gap area and extended slot area.The first boundary condition of the extended slot area was solved with the analytic method of the equivalent air-gap area magnetic field.The permanent magnets are equivalent to the surface current density.The uadrilateral isoparametric element method was used to calculate the magnet field of the extended slot area.The motor was rotating as a fixed step, and the flux of the phase windings was computed according to the magnetic field distribution of each slot.The curve of the induced electromotive force is the derivative to the time of the flux.The calculated result is considered to satisfy the needs in engineering practice by comparing with the test result.It verifies the correctness and effectiveness of the method.%解析数值结合法分析直驱式外转子分数槽表面磁钢永磁无刷电动机气隙磁场.将磁场求解范围划分为气隙区域和扩展槽区域,等效气隙区域磁场解析解得出槽区第一类边界条件,永磁体等效成面电流,用四边形等参元法计算扩展槽区域磁场分布.电机转子以固定角度转动,根据各槽磁场分布计算各相绕组磁链,拟合后对时间求导得到感应电势波形.将计算结果与实验结果比较,符合工程要求,证明了方法的正确性和有效性.

  19. Direct and Inverse Kinematic Analysis of a Leg-wheeled Passive Wheel Mobile Robot--Ice-skater Robot

    Institute of Scientific and Technical Information of China (English)

    宋立博; 张家梁; 吕恬生; 陆顺寿

    2003-01-01

    A new passive wheel type of leg-wheeled mobile robot based on rolling principle was introduced. To enhance the stability and maintain vertical to the ground of wheels, four passive wheels were installed at the end of four legs respectively and parallel mechanisms were used as legs. And an inertia coordinate system and a robot coordinate system were established, the related kinematic equation of the robot was gotten according to some assumptions after the configuration or the posture of wheels and legs was analyzed. At the same time, the turning conditions of the robot were also obtained. Based on the motion principle, the VSS-based logic control system was designed and the skating straight experiments and the turning experiments were conducted. And some conclusions were drawn.

  20. Photos taken during the assembly of the first 4-plane wheel prototype, built in 1998.

    CERN Multimedia

    Dixon, N.

    1998-01-01

    Photo 1 - End Cap. 4 -plane wheel prototype - One plane complete. Photo 2 - End Cap. 4 -plane wheel prototype - Radiator Foil. Photo 3 - End Cap. 4-plane wheel prototype - Glueing technique. Photo 4 - End Cap. 4-plane wheel prototype - Glueing ring. Photo 5 - End Cap. 4-plane wheel prototype - Glueing ring. Photo 6 - End Cap. 4-plane wheel prototype - Completed straw plane. Photo 7 - End Cap. 4-plane wheel prototype - Webs on assembly table. Photo 8 - End Cap. 4-plane wheel prototype - Operations on inner ring. Photo 9 - End Cap. 4-plane wheel prototype - Glueing operations. Photo 10 - End Cap. 4-plane wheel prototype - Glueing equipment. Photo 11 - End Cap. 4-plane wheel prototype - Assembly of 4-plane wheel. Photo 12 - End Cap. 4-plane wheel prototype - Positioning tool. Photo 13 - End Cap. 4-plane wheel prototype - Testing. Photo 14 - End Cap. 4-plane wheel prototype - Glued to web ring 2. Photo 15 - End Cap. 4-plane wheel prototype - Positioning tool. Photo 16 - End Cap. 4-plane wheel prototype - Detail o...

  1. Concept, design, performance and handling of the three-wheeled research vehicle the VW 'Scooter'

    Energy Technology Data Exchange (ETDEWEB)

    Dreyer, W.; Maretzke, J.; Pommer, E.

    With its VW Scooter, Volkswagen Research has come up with a vehicle concept representing a cross between a small sporty car and a powerful motorcycle. Characteristic features of the Scooter include its aerodynamic raindrop shape, its three wheels, its easily detachable gull-wing doors and an interior design that reminds one of a cockpit. The Scooter's low c/sub d/ drag keeps it very economical and environmentally compatible even at relatively high road speeds without detracting in the least from its most important feature the fun of driving it. This has been confirmed in tests done on vehicle handling. The Scooter offers safety from the dangers of tipping or pitching over during the longitudinal and lateral accelerations attainable on a non-slippery road surface. Its tendency to understeer and good directional stability are similar to those of comparable four-wheeled passenger cars even at high speeds.

  2. Infinity properads and infinity wheeled properads

    CERN Document Server

    Hackney, Philip; Yau, Donald

    2015-01-01

    The topic of this book sits at the interface of the theory of higher categories (in the guise of (∞,1)-categories) and the theory of properads. Properads are devices more general than operads, and enable one to encode bialgebraic, rather than just (co)algebraic, structures.   The text extends both the Joyal-Lurie approach to higher categories and the Cisinski-Moerdijk-Weiss approach to higher operads, and provides a foundation for a broad study of the homotopy theory of properads. This work also serves as a complete guide to the generalised graphs which are pervasive in the study of operads and properads. A preliminary list of potential applications and extensions comprises the final chapter.   Infinity Properads and Infinity Wheeled Properads is written for mathematicians in the fields of topology, algebra, category theory, and related areas. It is written roughly at the second year graduate level, and assumes a basic knowledge of category theory.

  3. Rover's Wheel Churns Up Bright Martian Soil

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Spirit acquired this mosaic on the mission's 1,202nd Martian day, or sol (May 21, 2007), while investigating the area east of the elevated plateau known as 'Home Plate' in the 'Columbia Hills.' The mosaic shows an area of disturbed soil, nicknamed 'Gertrude Weise' by scientists, made by Spirit's stuck right front wheel. The trench exposed a patch of nearly pure silica, with the composition of opal. It could have come from either a hot-spring environment or an environment called a fumarole, in which acidic, volcanic steam rises through cracks. Either way, its formation involved water, and on Earth, both of these types of settings teem with microbial life. Spirit acquired this mosaic with the panoramic camera's 753-nanometer, 535-nanometer, and 432-nanometer filters. The view presented here is an approximately true-color rendering.

  4. Optimization of Resilient Wheels for Rolling Noise Control

    Science.gov (United States)

    BOUVET, PASCAL; VINCENT, NICOLAS; COBLENTZ, ARNAUD; DEMILLY, FRANÇOIS

    2000-03-01

    Resilient wheels are currently used on light rail systems such as tramways to prevent squealing noise and to reduce impact noise. On the other hand, they are rarely found on main lines (passenger rolling stock and freight rolling stock). Although manufacturers often claim that resilient wheels are favourable for rolling noise control, no extensive theoretical investigation confirming this statement has been published to date. In this paper, it is shown how resilient wheels can be effectively optimised in order to reduce rolling noise emission, compared to a conventional monobloc wheel. A preliminary analysis of the physical phenomena accounting for rolling noise generation emphasizes the key design parameters affecting both wheel and radiation. These parameters are the radial dynamic stiffness and damping loss factor of the rubber layer. The tread mass is also relevant. The influence of these design parameters is then qualified by a parametric study performed with the TWINS software. An optimum radial dynamic stiffness of the resilient layer is found which depends on operating conditions. Reductions in overall rolling noise up to 3 dB(A) are calculated for the configurations investigated. However, poor selection of the design parameters can lead to a noise increase compared to a standard monobloc wheel. It is also shown that a proper design for rolling noise control will not affect wheel efficiency with regard to squeal noise.

  5. Diagnostics of the wheel thread of railway rolling stock

    Directory of Open Access Journals (Sweden)

    S. Yu. Buryak

    2013-02-01

    Full Text Available Purpose. At present, the devastating impact of faulty wheels on rails on the move is a major problem of railway transport. This factor is one of the most important, which causes the shift from traditional manual methods of verification and external examination to the automated diagnostic system of rolling stock in operation. Methodology. To achieve this goal the main types of wheel damages and the way they appear are analyzed. The methods for defects and abnormalities of the wheel thread determining as well as their advantages and disadvantages were presented. Nowadays these methods are under usage in both the international practice and in the one of the CIS countries. Findings. The faulty wheel sound on the move was researched and analyzed. The necessity of using the automated system, enabling one to reduce significantly the human factor is substantiated. Originality. The method to determine the wheel thread damage on the basis of a sound diagnostic is proposed. Practical value. Automatic tracking system of the wheels condition allows performing their more qualitative diagnostics, detecting a fault at the early stage and forecasting the rate of its extension. Besides detecting the location of the faulty wheel in the rolling stock, it is also possible to trace the dynamics of the fault extension and to give the recommendations on how to eliminate it.

  6. Low-cost real-time automatic wheel classification system

    Science.gov (United States)

    Shabestari, Behrouz N.; Miller, John W. V.; Wedding, Victoria

    1992-11-01

    This paper describes the design and implementation of a low-cost machine vision system for identifying various types of automotive wheels which are manufactured in several styles and sizes. In this application, a variety of wheels travel on a conveyor in random order through a number of processing steps. One of these processes requires the identification of the wheel type which was performed manually by an operator. A vision system was designed to provide the required identification. The system consisted of an annular illumination source, a CCD TV camera, frame grabber, and 386-compatible computer. Statistical pattern recognition techniques were used to provide robust classification as well as a simple means for adding new wheel designs to the system. Maintenance of the system can be performed by plant personnel with minimal training. The basic steps for identification include image acquisition, segmentation of the regions of interest, extraction of selected features, and classification. The vision system has been installed in a plant and has proven to be extremely effective. The system properly identifies the wheels correctly up to 30 wheels per minute regardless of rotational orientation in the camera's field of view. Correct classification can even be achieved if a portion of the wheel is blocked off from the camera. Significant cost savings have been achieved by a reduction in scrap associated with incorrect manual classification as well as a reduction of labor in a tedious task.

  7. Apparent mass of the human body in the vertical direction: Effect of a footrest and a steering wheel

    Science.gov (United States)

    Toward, M. G. R.; Griffin, M. J.

    2010-04-01

    The apparent mass of the seated human body influences the vibration transmitted through a car seat. The apparent mass of the body is known to be influenced by sitting posture but the influence of the position of the hands and the feet is not well understood. This study was designed to quantify the influence of steering wheel location and the position of a footrest on the vertical apparent mass of the human body. The influences of the forces applied by the hands to a steering wheel and by the feet to a footrest were also investigated. Twelve subjects were exposed to whole-body vertical random vibration (1.0 m s -2 rms over the frequency range 0.13-40.0 Hz) while supported by a rigid seat with a backrest reclined to 15°. The apparent mass of the body was measured with five horizontal positions and three vertical positions of a steering wheel and also with hands in the lap, and with five horizontal positions of a footrest. The influence of five forward forces (0, 50, 100, 150, 200 N) applied separately to the 'steering wheel' and the footrest were also investigated as well as a 'no backrest' condition. With their hands in their laps, subjects exhibited a resonance around 6.7 Hz, compared to 4.8 Hz when sitting upright with no backrest. In the same posture holding a steering wheel, the mass supported on the seat surface decreased and there was an additional resonance at 4 Hz. Moving the steering wheel away from the body reduced the apparent mass at the primary resonance frequency and increased the apparent mass around the 4 Hz resonance. As the feet moved forward, the mass supported on the seat surface decreased, indicating that the backrest and footrest supported a greater proportion of the subject weight. Applying force to either the steering wheel or the footrest reduced the apparent mass at resonance and decreased the mass supported on the seat surface. It is concluded that the positions and contact conditions of the hands and the feet affect the biodynamic

  8. Impulsive dynamics and stabilization of a single wheel robot

    Institute of Scientific and Technical Information of China (English)

    Ou Yongsheng; Wu Xinyu; Xu Yangsheng

    2011-01-01

    The impulsive motion of a dynamically stabilized robot-Gyrover, which is a single-wheel gyroscopically stabilized robot is studied. A method based on the D' Alembert-Lagrange principle is proposed to develop the impulsive dynamic model of the single wheel robot. This method that can be used to find ways to investigate a single wheel mobile robot rolling on a rough terrain is tested using the experimental platform Gyrover. The conditions of falling over without actuators are addressed. Simulations that validate the analysis are provided as well.

  9. Life Assessment and Life Extension of an Aircraft Wheel

    Directory of Open Access Journals (Sweden)

    M. Aghaie-Khafri

    2012-01-01

    Full Text Available The effect of heat treatment and shot peening on the fatigue life of an aluminum aircraft wheel was studied. The effect of residual stress and heat treatment on the fatigue of specimens was studied by means of fatigue testing, residual stress measurement, and fractography. Finite element simulation was used for life assessment and evaluation of the effect of surface treatments on the life extension of the aircraft wheel. The results obtained show that the operational life of the aircraft wheel extended by imposed compressive residual stress and aging treatment.

  10. Light wheel confined in a purely dielectric composite waveguide.

    Science.gov (United States)

    Ye, Yu Qian; Jin, Yi; He, Sailing

    2009-03-16

    A properly designed composite waveguide consisting of a one-dimensional photonic crystal waveguide and a conventional dielectric waveguide is proposed for the realization of a localized "light wheel". Light confinedly rotating between the two waveguides is numerically demonstrated and explained physically in detail. A delocalized "light wheel" is found at the band gap edge caused by contra-directional coupling between the two waveguides. Because of this delocalized "light wheel" , the composite waveguide can be used to trap light as a cavity, and a quality factor of 9 x 10(3) is achieved as an example. The present structure is completely dielectric and thus easy to realize with a low loss.

  11. Study on Drive System of Hybrid Tree Harvester

    Directory of Open Access Journals (Sweden)

    Shen Rong-feng

    2017-01-01

    Full Text Available Hybrid tree harvester with a 60 kW diesel engine combined with a battery pile could be a “green” forest harvesting and transportation system. With the new design, the diesel engine maintains a constant engine speed, keeping fuel consumption low while charging the batteries that drive the forwarder. As an additional energy saving method, the electric motors work as generators to charge the battery pile when the vehicle moves downhill. The vehicle is equipped with six large wheels providing high clearance over uneven terrain while reducing ground pressure. Each wheel is driven via a hub gear by its own alternating current motor, and each of the three wheel pairs can be steered independently. The combination of the diesel engine and six electric motors provides plenty of power for heavy lifting and pulling. The main component parameters of the drive system are calculated and optimized with a set of dynamics and simulated with AVL Cruise software. The results provide practical insights for the fuel tree harvester and are helpful to reduce the structure and size of the tree harvester. Advantage Environment provides information about existing and future products designed to reduce environmental impacts.

  12. Dynamics of the tractor (4x2, and the occurrence of parasitic power circulation in the drive (4x4

    Directory of Open Access Journals (Sweden)

    Petrović Predrag T.

    2015-01-01

    Full Text Available When moving tractors with four-wheel drive (4x4 adhesion is achieved by utilization of the entire weight of the vehicle in relation to the movement of vehicles with two-wheel drive (4x2, when the exploitation only part of the weight of the vehicle, which is transmitted through the two operating point. Pulling characteristics in both variants depend on the achievement of optimum. In case that there is a incompatibility of kinematic movement of one wheel, relative to the second drive axle, and in certain types of transmissions, so-called. blocked by divorce, there is the possibility of useless forces or parasitic power, which not only does not participate in the implementation of the tractor, but is opposed to his where aborts conditions of movement of the wheels and the contact surface. In this paper, we give a short overview of the dynamics of movement of the tractor on the rise, with the drive (4x2 and review the possibility of parasitic forces in the drive (4x4 and the effect that created such a power could result in the tractor.

  13. CFD simulations to optimize the blade design of water wheels

    Science.gov (United States)

    Quaranta, Emanuele; Revelli, Roberto

    2017-05-01

    At low head sites and at low discharges, water wheels can be considered among the most convenient hydropower converters to install. The aim of this work is to improve the performance of an existing breastshot water wheel by changing the blade shape using computational fluid dynamic (CFD) simulations. Three optimal profiles are investigated: the profile of the existing blades, a circular profile and an elliptical profile. The results are validated by performing experimental tests on the wheel with the existing profile. The numerical results show that the efficiency of breastshot wheels is affected by the blade profile. The average increase in efficiency using the new circular profile is about 4 % with respect to the profile of the existing blades.

  14. Implementations of newly developed wheel and rail profile design methods

    Directory of Open Access Journals (Sweden)

    Gang Shen

    2014-06-01

    Full Text Available The developments of a series of wheel profile computer aided methods based on the RRDF or CADF contact functions are briefly described. Since 2001 the implementations of these methods are carried out according to different requirements for tramway vehicles, metro vehicles, and main line EMU vehicles etc. It is found that the main advantage of these new methods in wheel profile design is obtaining the proper wheel profiles to efficiently reduce the wears of wheel and rail and to improve the performances of both stability and curving performances. Moreover, post process of transfering a profile with discrete points to a profile with arc and line combinations is studied with a high precision.

  15. Laser-assisted Grinding Wheel Dressing (Ⅱ)-Experimental Researches

    Institute of Scientific and Technical Information of China (English)

    Ming CHEN; Fanghong SUN; Youngmoon LEE; Seunghan YANG; Jongchan LEE

    2003-01-01

    Most of the mechanical dressing technologies for resin bonded superabrasive grinding wheels are time consumingand costly. Based on the outcomes of the simulations in the previous study, this paper demonstrates the comprehensive researches on the laser-ass

  16. Development of Diamond-like Carbon Fibre Wheel

    Institute of Scientific and Technical Information of China (English)

    魏源迁; 山口勝美; 洞口巌; 竹内雅之

    2004-01-01

    A unique diamond-like carbon (DLC) grinding wheel was developed, in which the DLC fibres were made by rolling Al sheets coated with DLC films and aligned normally to the grinding wheel surface by laminating Al sheets together with DLC fibres. In this paper, the formation process of DLC fibres and the fabrication process of a DLC fibre wheel were investigated. Many grinding experiments were also carried out on a precision NC plane milling machine using a newly developed DLC wheel. Grinding of specimens of silicon wafers, optical glasses, quartz, granites and hardened die steel SKD11 demonstrated the capabilities of nanometer surface finish. A smooth surface with a roughness value of Ra2.5nm (Ry26nm) was achieved.

  17. Wheel slip dump valve for railway braking system

    Science.gov (United States)

    Zhang, Xuan; Zhang, LiHao; Li, QingXuan; Shi, YanTao

    2017-09-01

    As we all know, pneumatic braking system plays an important role in the safety of the whole vehicle. In the anti slip braking system, the pressure of braking cylinder can be adjusted by the quick power response of wheel slip dump valve, so that the lock situation won’t occur during vehicle service. During the braking of railway vehicles, the braking force provided by braking disc reduces vehicle’s speed. But the locking slip will happen due to the oversize of braking force or the reduction of sticking coefficient between wheel and rail. It will cause not only the decline of braking performance but also the increase of braking distance. In the meanwhile, it will scratch the wheel and influence the stable running of vehicles. Now, the speed of passenger vehicle has been increased. In order to shorten the braking distance as far as possible, sticking stickiness must be fully applied. So the occurrence probability of wheel slip is increased.

  18. Modeling of Railway Wheels Made of Austempered Ductile Iron

    Directory of Open Access Journals (Sweden)

    Giętka T.

    2016-12-01

    Full Text Available A person is forced to travel constantly throughout its entire life. The more modern the society, the greater the pace of life, and the greater the need to be present in many places that are distant from each other. Rail transport occupies second place in this regard, after air transport. This means of transportation has many advantages, however the time of travel requires continuous improvement, in particular, to match the competition. One factor limiting the speed of travel is inter-operation between the wheels – rail kinematic pair. When rolling on a rail, a wheel is subject to wear, which unavoidably leads to its degradation. Frequent damage to both the wheel and the rail necessitates consideration of this problem. Because any changes to the rail are very expensive and time-consuming, this paper focuses on possible changes to the wheel.

  19. Research on CNC Turning System of Aspheric Machining Grinding Wheel

    Institute of Scientific and Technical Information of China (English)

    ZOU Qin; GUO Yin-biao

    2005-01-01

    The technology of machining aspheric surface with high precision is the premise for the application of aspheric surface. The grinding machining with error compensation is a commonly used method to machine aspheric surface, which will directly influence the quality of aspheric workpiece surface. Multifunctional CNC grinding wheel truing system is a four-axis CNC truing system which can be applied to grinding wheel truing. In this system,DSP-based multi-axes motion control card is adopted as the controller, and visual C++ is used as development tool.When the design of hardware and software is completed, the system can implement truing of various grinding wheel with high precision aspheric machining such as plane grinding wheel, arc grinding one, and sphere grinding one.

  20. Miniature Reaction Wheel for Small Satellite Control Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall goal of this project is to design, develop, demonstrate, and deliver a miniature, high torque, low-vibration reaction wheel for use on small satellites....

  1. Scaling Relations for Wheeled Locomotion in Granular Media

    Science.gov (United States)

    Slonaker, James; Kamrin, Ken

    Vehicular wheel design for use on granular material has not currently been perfected. Resistive Force Theory (RFT) is a reduced-order empirical model for granular drag, which shows promise to help simulate and understand locomotion processes to design more efficient wheels. Here we explore the fundamental scaling relations derived from RFT and their experimental validation. Similar to the non-dimensional scaling relations in fluid mechanics, the relative simplicity of RFT asserts that only one material parameter, the ''grain-structure coefficient'', is required, which reduces the complexity of the non-dimensional groups implied by the system. Therefore, wheels with differing input design parameters like size, mass, shape and even gravity, can be tested and their performance related to each other in predictable ways. We experimentally confirmed these relations by testing with 3D printed wheel geometries in a controlled sand bed.

  2. Finite Element Analysis of Wheel Rim Using Abaqus Software

    Directory of Open Access Journals (Sweden)

    Bimal Bastin

    2017-02-01

    Full Text Available The rim is the "outer edge of a wheel, holding the tire". It makes up the outer circular design of the wheel on which the inside edge of the tire is mounted on vehicles such as automobiles. A standard automotive steel wheel rim is made from a rectangular sheet metal. Design is an important industrial activity which influences the quality of the product being produced. The wheel rim is modeled by using modeling software SOLIDWORKS . Later this modal is imported to ABAQUS for analysis. Static load analysis has been done by applying a pressure of 5N/mm2 . The materials taken for analysis are steel alloy, Aluminium, Magnesium, and Forged Steel. The displacement occurred to the rim is noted after applying the static load to different materials and maximum principal stresses were also noted

  3. TECHNOLOGICAL FEATURES OF MANUFACTURE OF REINFORCED RAIL WHEEL

    Directory of Open Access Journals (Sweden)

    I. O. Vakulenko

    2008-01-01

    Full Text Available The results of research of influence of parameters of thermomechanical hardening on the structure, complex of physico-mechanical and service properties of hardened railway wheels are presented.

  4. BICARBONATE OF SODA BLASTING TECHNOLOGY FOR AIRCRAFT WHEEL PAINTING

    Science.gov (United States)

    This evaluation addressed product quality, waste reduction/pollution prevention and economics in replacing chemical solvent strippers with a bicarbonate of soda blasting technology for removal of paint from aircraft wheels. The evaluation was conducted in the Paint Stripping Sho...

  5. Obstacle performance of cobalt-enriching crust wheeled mining vehicle

    Institute of Scientific and Technical Information of China (English)

    HUANG Zhong-hua; LIU Shao-jun; XIE Ya

    2006-01-01

    A cobalt-enriching crust mining vehicle with four independent driven wheels was proposed. The influence of center-of-gravity position of mining vehicle on obstacle performance was studied. The results show that the mining vehicle has optimal obstacle performance with center-of-gravity position in the middle of suspension. A virtual prototype based on ADAMS software was built and its obstacle performance was simulated. Simulation results show that the mining vehicle with four independent driven wheels has excellent obstacle performance, the maximum climbing capacity is no less than 30°, the maximal ditch width and shoulder height are no less than wheel radius ofmining vehicle. Thus wheeled mining vehicle is feasible for cobalt-enriching crust commercial mining.

  6. Numerical simulation of wheel wear evolution for heavy haul railway

    Institute of Scientific and Technical Information of China (English)

    王璞; 高亮

    2015-01-01

    The prediction of the wheel wear is a fundamental problem in heavy haul railway. A numerical methodology is introduced to simulate the wheel wear evolution of heavy haul freight car. The methodology includes the spatial coupling dynamics of vehicle and track, the three-dimensional rolling contact analysis of wheel-rail, the Specht’s material wear model, and the strategy for reproducing the actual operation conditions of railway. The freight vehicle is treated as a full 3D rigid multi-body model. Every component is built detailedly and various contact interactions between parts are accurately simulated, taking into account the real clearances. The wheel−rail rolling contact calculation is carried out based on Hertz’s theory and Kalker’s FASTSIM algorithm. The track model is built based on field measurements. The material loss due to wear is evaluated according to the Specht’s model in which the wear coefficient varies with the wear intensity. In order to exactly reproduce the actual operating conditions of railway, dynamic simulations are performed separately for all possible track conditions and running velocities in each iterative step. Dimensionless weight coefficients are introduced that determine the ratios of different cases and are obtained through site survey. For the wheel profile updating, an adaptive step strategy based on the wear depth is introduced, which can effectively improve the reliability and stability of numerical calculation. At last, the wear evolution laws are studied by the numerical model for different wheels of heavy haul freight vehicle running in curves. The results show that the wear of the front wheelset is more serious than that of the rear wheelset for one bogie, and the difference is more obvious for the outer wheels. The wear of the outer wheels is severer than that of the inner wheels. The wear of outer wheels mainly distributes near the flange and the root;while the wear of inner wheels mainly distributes around the

  7. A novel multi-drive electric vehicle system control based on multi-input multi-output PID controller

    Directory of Open Access Journals (Sweden)

    Gasbaoui Brahim

    2012-01-01

    Full Text Available In-wheel-motor drive electric vehicle (EV is an innovative configuration of the modern EV, in which each wheel is driven individually by an electric motor. The classical traction motor control called the Independent Machine Control Structure (IMCS using a PID speed controller presents major inconveniences in modern EV safety, when the proposed control can not ensure stability of the EV with differing road topology and variations of speed. A new approach is proposed for a control of a two-in-wheel-motor drive EV, called the Maximum Control Structure MCS. This is based on a multivariable PID (MIMO-PID strategy, which is employed to estimate the linear speed error of each of the two back driving wheels, when the error of each wheel is taken into account in the other speed control computations. Simulation results show that the new control system presents increased safety for the EVs compared with the IMCS strategy and can maintain the error slip rate within the optimal range, ensuring the stability of the vehicle either in a straight or a curved line.

  8. Wheel rolling constraints and slip in mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Shekhar, S. [Oak Ridge National Lab., TN (United States). Robotics and Process Systems Div.

    1996-06-01

    It is widely accepted that dead-reckoning based on the rolling with no-slip condition on the wheels is not a reliable method to ascertain the position and orientation of a mobile robot for any reasonable distance. The authors establish that wheel slip is inevitable under the dynamic model of motion using classical results on the accessibility and controllability in nonlinear control theory and an analytical model of rolling of two linearly elastic bodies.

  9. High Speed, Low Weight Momentum/Reaction Wheels

    OpenAIRE

    1999-01-01

    Advancements in several critical areas have made possible lightweight, strong and highly reliable momentum / reaction wheels. The development of reliable bearings with design features that allow high speed operation for space flight applications has significantly altered the weight / speed / wheel design considerations. Current designs typically operate at speeds at or below 6,000 RPM The new retainerless can achieve speeds 10 times that and meet or improve all other significant bearing opera...

  10. Voluntary wheel running: a review and novel interpretation.

    Science.gov (United States)

    Sherwin

    1998-07-01

    Voluntary wheel running by animals is an activity that has been observed and recorded in great detail for almost a century. This review shows that it is performed, often with startling intensity and coordination, by a wide variety of wild, laboratory and domestic species with diverse evolutionary histories. However, despite the plethora of published studies on wheel running, there is considerable disagreement between many findings, thus leading to a lack of consensus on explanations of the causality and function. In the initial part of this review, I discuss the internal and external factors that may be involved in the causality of this behaviour, with an emphasis on disparities in both the factual and theoretical development of the subject. I then address the various proposed functions of wheel running, again highlighting evidence to the contrary. This leads to the conclusion that any single theory on the basis of wheel running is likely to be simplistic with little generality. I then present a novel, behaviour-based interpretation in which it is argued that wheel running has no directly analogous naturally occurring behaviour, it is (sometimes) performed for its own sake per se rather than as a redirected or substitute activity, and studies on motivation show that wheel running is self-reinforcing and perceived by animals as 'important'. This review proposes that wheel running may be an artefact of captive environments or of the running-wheel itself, possibly resulting from feedback dysfunction. I also discuss the ubiquity and intensity of its performance, along with its great plasticity and maladaptiveness, all indicating that if it is an artefact, it is nevertheless one of great interest to behavioural science. Copyright 1998 The Association for the Study of Animal Behaviour.

  11. Analysis of fault conditions in permanentmagnet in-wheel motors

    OpenAIRE

    Liao, Yonghui

    2011-01-01

    The use of light in-wheel motors is an attractive alternative for smaller passenger vehicles in urban areas. An in-wheel motor design has already been developed in a previous master thesis project. In this project, the proposed design is further analysed during electrical faults using a FEM software package (JMAG). A failure modes and effects analysis (FMEA) is carried out to identify the important faults. The faults simulated in this project are: phase short circuit, phase open circuit, high...

  12. Wheel rolling constraints and slip in mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Shekhar, S.

    1997-03-01

    It is widely accepted that dead reckoning based on the rolling with no slip condition on wheels is not a reliable method to ascertain the position and orientation of a mobile robot for any reasonable distance. We establish that wheel slip is inevitable under the dynamic model of motion using classical results on the accessibility and controllability in nonlinear control theory and an analytical model of rolling of two linearly elastic bodies.

  13. Wheel rolling constraints and slip in mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Shekhar, S.

    1997-03-01

    It is widely accepted that dead reckoning based on the rolling with no slip condition on wheels is not a reliable method to ascertain the position and orientation of a mobile robot for any reasonable distance. The author establishes that wheel slip is inevitable under the dynamic model of motion using classical results on the accessibility and controllability in nonlinear control theory and an analytical model of rolling of two linearly elastic bodies.

  14. Modelling of Dynamics of a Wheeled Mobile Robot with Mecanum Wheels with the use of Lagrange Equations of the Second Kind

    Science.gov (United States)

    Hendzel, Z.; Rykała, Ł.

    2017-02-01

    The work presents the dynamic equations of motion of a wheeled mobile robot with mecanum wheels derived with the use of Lagrange equations of the second kind. Mecanum wheels are a new type of wheels used in wheeled mobile robots and they consist of freely rotating rollers attached to the circumference of the wheels. In order to derive dynamic equations of motion of a wheeled mobile robot, the kinetic energy of the system is determined, as well as the generalised forces affecting the system. The resulting mathematical model of a wheeled mobile robot was generated with the use of Maple V software. The results of a solution of inverse and forward problems of dynamics of the discussed object are also published.

  15. HARMONIC DRIVE SELECTION

    Directory of Open Access Journals (Sweden)

    Piotr FOLĘGA

    2014-03-01

    Full Text Available The variety of types and sizes currently in production harmonic drive is a problem in their rational choice. Properly selected harmonic drive must meet certain requirements during operation, and achieve the anticipated service life. The paper discusses the problems associated with the selection of the harmonic drive. It also presents the algorithm correct choice of harmonic drive. The main objective of this study was to develop a computer program that allows the correct choice of harmonic drive by developed algorithm.

  16. Designing Omni-Directional Mobile Robot with Mecanum Wheel

    Directory of Open Access Journals (Sweden)

    Jefri E.M. Salih

    2006-01-01

    Full Text Available This study presents the processes undertaken in the design and development of an intelligent omni-directional mobile robot using four custom-made mecanum wheels. The mecanum wheel developed consists of nine rollers made from delrin. All mecanum wheels are independently powered using four units of precisian gear DC motors and the wheel/motor assemblies were mounted directly to the robot chassis made using an aluminum frame. A four channel high power H-bridge using 2 units of LMD 18200 motor drivers IC circuit was design, built and interfaced to a BasicStamp (BS2 microcontroller board. Basic mobility algorithm using BasicStamp software was developed to test the basic mobility capabilities and test the qualitative view of the system's mobility performance. An experiment was set-up to analyze the motion characteristic of the mobile robot motion in Y-axis, X-axis and rotary motion. Data from the experiment will be used for mathematically model for mobile robot platform and speed controller modeling and design. Mecanum wheel mobile robot provides a convenient platform for further development in the mobile platform. The combination of mechanical design on the wheel and chassis, motion control and multiple input/output sensors allow the exploration of large number of control algorithm and software to be implemented to the robot for practical applications.

  17. Milestone reached for the Big Wheels of the Muon Spectrometer

    CERN Multimedia

    Sandro Palestini

    The assembly and integration of the Big Wheels sectors of the Muon Spectrometer is reaching its conclusion, with only a few sectors of Wheel TGC-A-3 remaining on the assembly stations in building 180. The six trigger chambers (TGCs) wheels and two precision chambers wheels (MDTs) contain in total 104 sectors, which were assembled, equipped with detectors and fully tested over a period of two years. The few remaining Big Wheel sectors still stored in building 180 Most of the sectors left building 180 over the last twelve months, and form the six Wheels currently installed in the ATLAS detector. The remaining two will be installed before the end of the summer. The commitment of the personnel from the many teams who contributed to different parts of the project was essential to its success. In particular, teams coming from countries of different traditions and languages, such as China, Israel, Japan, Pakistan, Russia and USA contributed and collaborated very effectively to the timely completion of the p...

  18. On fractional control method for four-wheel-steering vehicle

    Institute of Scientific and Technical Information of China (English)

    CHEN Ning; CHEN Nan; CHEN YanDong

    2009-01-01

    Four-wheel-steering (4WS) system can enhance vehicle cornering ability by steering the rear wheels in accordance with the front wheels steering and vehicle status. With such steering control system, it becomes possible to improve the lateral stability and handling performance, in this paper, a new control method for 4WS vehicle is proposed, its rear wheels steering angle is in accordance with the angle of front wheels steering and vehicle yaw rate, and the effects of front wheels steering angle velocity are considered by adopting the fractional derivative theory. Some design specifications for control law are also given. The effects of the control method are verified by a kind of numerical scheme presented in this paper. The dynamic characteristics such as the side-slip angle and the yaw angle velocity of the vehicle gravity center are compared among three kinds of vehicles with different control methods. And the kinematics characteristics such as turning radius between 4WS and 2WS are also discussed. Nu-merical simulation shows that the control method presented can improve the transient response and reduce the turning radius of 4WS vehicle.

  19. On fractional control method for four-wheel-steering vehicle

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Four-wheel-steering (4WS) system can enhance vehicle cornering ability by steering the rear wheels in accordance with the front wheels steering and vehicle status. With such steering control system, it becomes possible to improve the lateral stability and handling performance. In this paper, a new control method for 4WS vehicle is proposed, its rear wheels steering angle is in accordance with the angle of front wheels steering and vehicle yaw rate, and the effects of front wheels steering angle velocity are considered by adopting the fractional derivative theory. Some design specifications for control law are also given. The effects of the control method are verified by a kind of numerical scheme presented in this paper. The dynamic characteristics such as the side-slip angle and the yaw angle velocity of the vehicle gravity center are compared among three kinds of vehicles with different control methods. And the kinematics characteristics such as turning radius between 4WS and 2WS are also discussed. Nu- merical simulation shows that the control method presented can improve the transient response and reduce the turning radius of 4WS vehicle.

  20. On Optimizing Steering Performance of Multi-axle Vehicle Based on Driving Force Control

    Directory of Open Access Journals (Sweden)

    Wu Zhicheng

    2017-01-01

    Full Text Available The steering performance of multi-axle vehicle with independent driving system is affected by the distribution of the wheel driving force. A nonlinear vehicle dynamics model including magic formula tire model for describing 11 DoF four-axle vehicle with dual-front-axle-steering (DFAS system was presented. The influence of different driving force distribution scheme on the steering performance of the vehicle was analyzed. A control strategy for improving the steady response and transient response of the vehicle steering is proposed. The results show: For the steady response, setting different drive force for internal and external wheels according to the actual steering characteristics of the vehicle can effectively improve its steering characteristics; For the transient response, adopting the zero sideslip angle control strategy and using the PID control algorithm to control the driving force of the outside wheel of tear-two-axle, under angle step input, the vehicle sideslip angle can quickly stabilize to 0 and yaw rate also significantly decreases.

  1. Results of investigating the load on carrying parts of the Rs-1200 bucket wheel excavator

    Energy Technology Data Exchange (ETDEWEB)

    Tasev, D.; Mikhalkov, Z.; Tokmakchiev, S.

    1983-08-01

    Overburden removal in the Maritsa Iztok coal basin is carried out by Rs-1200 bucket wheel excavators under continuously worsening working conditions. The depth and cutting resistance of overburden require use of more powerful excavators. In order to determine whether the Rs-1200 excavator has enough power to be employed under worsening conditions the stress at critical points of the boom was measured under static and dynamic loads by means of the TSA-4A tensometer, UM-131 measuring device and N-115 vibration recorder. It was found that the stresses at critical points of the boom do not exceed 5,400-5,900 N/cm/SUP/2 under static or dynamic loads. The combined static and dynamic loads do not cause stresses over 9,100 N/cm/SUP/2. Investigations show that the power of the electric motor driving the bucket wheel can be increased by about 30%. Details of measuring techniques and results of load testing are given. (In Bulgarian)

  2. Design and simulation of an image-based fuzzy tracking controller for a wheeled mobile robot

    Science.gov (United States)

    Shiao, Ying Shing; Wu, Ching Wei

    2011-12-01

    Image processing algorithms and fuzzy logic method are used to design a visual tracking controller for mobile robot navigation. In this paper, a wheeled mobile robot is equipped with a camera for detecting its task space. The grabbed environmental images are treated using image recognition processing to obtain target's size and position. The images are treated using input membership functions as the fuzzy logic controller input. The recognized target's size and position are input into a fuzzy logic controller in which fuzzy rules are used for inference. The inference results are output to the defuzzifier to obtain a physical control signal to control the mobile robot's movement. The velocity and direction of the mobile robot are the output of fuzzy logic controller. The differences in velocities for two wheels are used to control the robot's movement directions. The fuzzy logic controller outputs the control commands to drive the mobile robot to reach a position 50cm front of the target location. The simulation results verify that the proposed FLC is effective in navigating the mobile robot to track a moving target.

  3. Frontend and Backend Electronics for the ATLAS New Small Wheel Upgrade

    CERN Document Server

    Martinez Outschoorn, Verena; The ATLAS collaboration

    2016-01-01

    The Phase-I and Phase-II upgrades of the LHC accelerator will increase the LHC instantaneous luminosity to 2×1034 cm-2s-1 and 7.5×1034 cm-2s-1, respectively. The luminosity increase drastically impacts the ATLAS trigger and readout data rates. The present ATLAS small wheel muon detector will be replaced with a New Small Wheel (NSW) detector in 2019. The NSW will feature two new detector technologies, Resistive Micromegas (MM) and small strip Thin Gap Chambers (sTGC) conforming a system of ~2.4 million readout channels. Both detectors will be used for muon triggering and precision tracking. A common readout path and two separate trigger paths are developed for these two detector technologies. The frontend electronics will be implemented in about 8000 boards including the design of 4 custom ASICs capable of driving trigger and tracking primitives to the backend trigger processor and readout system. The readout data flow is designed through a high-throughput network approach. The large number of readout channe...

  4. Optimal design for an end face engagement worm gear with multiple worm-wheel meshing

    Science.gov (United States)

    Deng, Xingqiao; Zhu, Weibing; Chen, Yonghong; Chen, Shouan; Wang, Jinge

    2017-01-01

    To solve the problem for lacking a special mechanical transmission that could provide multiple outputs with high transmission efficiency and good lubrication in the modern industrial, a novel worm gear, named end face engagement worm gear, with multiple worm-wheel meshing is proposed for the first time. The essential parameters for the worm gear are optimized to enhance lubrication and meshing properties. Moreover, analysis of variance(ANOVA) is applied to determine the optimum levels and to determine the influence of parameters. The ANOVA results show that the novel end face engagement worm gear with multiple worm wheels provides high lubrication(the lubrication angle is more than 89°) and meshing performance(the induce normal curvature is less than 0.0002 mm-1). The interaction between center distance and roller slant distance most strongly influences the lubrication angle(contributed 51.6%), followed by the parameters of center distance(contributed 25.0%), roller slant distance(contributed 16.4%), tooth angle of gear, gear ratio, and roller radius. In addition, roller radius most strongly influences the induced normal curvature(contributed 39.4%), followed by roller slant distance(contributed 15.2%), tooth angle of the gear(contributed 9.0%), center distance, and gear ratio. The proposed worm gear helps to enrich the no-backlash high precision worm drive and the optimal design method can provide a useful reference on performance improvement of other worm gear.

  5. Performance analysis of four-partition desiccant wheel and hybrid dehumidification air-conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jongsoo; Yamaguchi, Seiichi; Saito, Kiyoshi; Kawai, Sunao [Department of Applied Mechanics and Aerospace Engineering, School of Fundamental Science and Engineering, Waseda University, 3-4-1-58-210 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan)

    2010-05-15

    A desiccant dehumidification system with air can decrease energy consumption because it can be driven by low-grade waste heat below 80 C. If this system can be driven by low-temperature heat sources whose temperature is below 50 C, exhausted heat from fuel cells or air conditioners that exist everywhere can be used as heat sources. This could lead to considerable energy saving. This study provides a detailed evaluation of the performance of a four-partition desiccant wheel to make a low-temperature driving heat source possible and achieve considerable energy saving by the simulation and experiment. Further, the study investigates the in-depth performance of a hybrid air-conditioning system with a four-partition desiccant wheel by simulation. As a result, it was clear that there exists an optimum rotational speed to maximize the dehumidification performance and that the hybrid air-conditioning system improves COP by approximately 94% as compared to the conventional vapour compression-type refrigerator. (author)

  6. Mechatronic track guidance on disturbed track: the trade-off between actuator performance and wheel wear

    Science.gov (United States)

    Kurzeck, Bernhard; Heckmann, Andreas; Wesseler, Christoph; Rapp, Matthias

    2014-05-01

    Future high-speed trains are the main focus of the DLR research project Next Generation Train. One central point of the research activities is the development of mechatronic track guidance for the two-axle intermediate wagons with steerable, individually powered, independently rotating wheels. The traction motors hereby fulfil two functions; they concurrently are traction drives and steering actuators. In this paper, the influence of the track properties - line layout and track irregularities - on the performance requirements for the guidance actuator is investigated using multi-body models in SIMPACK®. In order to compromise on the design conflict between low wheel wear and low steering torque, the control parameters of the mechatronic track guidance are optimised using the DLR in-house software MOPS. Besides the track irregularities especially the increasing inclination at transition curves defines high actuator requirements due to gyroscopic effects at high speed. After introducing a limiter for the actuating variables into the control system, a good performance is achieved.

  7. Paper recycling framework, the "Wheel of Fiber".

    Science.gov (United States)

    Ervasti, Ilpo; Miranda, Ruben; Kauranen, Ilkka

    2016-06-01

    At present, there is no reliable method in use that unequivocally describes paper industry material flows and makes it possible to compare geographical regions with each other. A functioning paper industry Material Flow Account (MFA) that uses uniform terminology and standard definitions for terms and structures is necessary. Many of the presently used general level MFAs, which are called frameworks in this article, stress the importance of input and output flows but do not provide a uniform picture of material recycling. Paper industry is an example of a field in which recycling plays a key role. Additionally, terms related to paper industry recycling, such as collection rate, recycling rate, and utilization rate, are not defined uniformly across regions and time. Thus, reliably comparing material recycling activity between geographical regions or calculating any regional summaries is difficult or even impossible. The objective of this study is to give a partial solution to the problem of not having a reliable method in use that unequivocally describes paper industry material flows. This is done by introducing a new material flow framework for paper industry in which the flow and stage structure supports the use of uniform definitions for terms related to paper recycling. This new framework is termed the Detailed Wheel of Fiber.

  8. Control of two Wheeled Welding Mobile Manipulator

    Directory of Open Access Journals (Sweden)

    M. D. Ngo

    2008-11-01

    Full Text Available A three-linked manipulator mounted on a two-wheeled mobile platform is used to weld a long curved welding path. A welding torch mounted at the end of a manipulator of the welding mobile manipulator (WMM must be controlled for tracking a welding path with constant velocity and constant welding angle of torch. In this paper, a decentralized control method is applied to control the WMM considered as two separate subsystems such as a mobile platform and a manipulator. Two decentralized motion controllers are designed to control two subsystems of WMM, respectively. Firstly, based on a tracking error vector of the manipulator and a feedback motion of the mobile platform, a kinematic controller is designed for manipulator. Secondly, based on an another tracking error vector of the mobile platform and a feedback angular velocities of revolution joints of three-link, a sliding mode controller is designed for the mobile platform. These controllers are obtained based on the Lyapunov's function and its stability condition to ensure for the tracking error vectors to be asymptotically stable. Furthermore, simulation and experimental results are presented to illustrate the effectiveness of the proposed algorithm.

  9. Opportunity's Surroundings After Sol 1820 Drive

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,820th to 1,822nd Martian days, or sols, of Opportunity's surface mission (March 7 to 9, 2009). South is at the center; north at both ends. The rover had driven 20.6 meters toward the northwest on Sol 1820 before beginning to take the frames in this view. Tracks from that drive recede southwestward. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and small exposures of lighter-toned bedrock. This view is presented as a cylindrical projection with geometric seam correction.

  10. H∞ Control of Four-Wheel-Independent-Drive Electric Vehicles with Random Time-Varying Delays

    Directory of Open Access Journals (Sweden)

    Gang Qin

    2015-01-01

    Full Text Available The random time-varying delays would reduce control performance and even deteriorate the EV system. To deal with random time-varying delays and achieve a real-time steady-state response, considering randomness of delay and a rapid response, an H∞-based delay-tolerant linear quadratic regulator (LQR control method based on Taylor series expansion is proposed in this paper. The results of cosimulations with Simulink and CarSim demonstrate the effectiveness of the proposed controller through the control performance of yaw rate, sideslip angle, and the running track. Moreover, the results of comparison with the other controller illustrate the strength of explicitly.

  11. Development of Cryogenic Filter Wheels for the HERSCHEL Photodetector Array Camera & Spectrometer (PACS)

    Science.gov (United States)

    Koerner, Christian; Kampf, Dirk; Poglitsch, Albrecht; Schubert, Josef; Ruppert, U.; Schoele, M.

    2014-01-01

    This paper describes the two PACS Filter Wheels that are direct-drive rotational mechanisms operated at a temperature below 5K inside the PACS focal plane unit of the Herschel Satellite. The purpose of the mechanisms is to switch between filters. The rotation axis is pivoted to the support structure via a slightly preloaded pair of ball bearings and driven by a Cryotorquer. Position sensing is realized by a pair of Hall effect sensors. Powerless positioning at the filter positions is achieved by a magnetic ratchet system. The key technologies are the Cryotorquer design and the magnetic ratchet design in the low temperature range. Furthermore, we will report on lessons learned during the development and qualification of the mechanism and the paint.

  12. PD-like controller for delayed bilateral teleoperation of wheeled robots

    Science.gov (United States)

    Slawiñski, E.; Mut, V.; Santiago, D.

    2016-08-01

    This paper proposes a proportional derivative (PD)-like controller applied to the delayed bilateral teleoperation of wheeled robots with force feedback in face of asymmetric and varying-time delays. In contrast to bilateral teleoperation of manipulator robots, in these systems, there is a mismatch between the models of the master and slave (mobile robot), problem that is approached in this work, where the system stability is analysed. From this study, it is possible to infer the control parameters, depending on the time delay, necessary to assure stability. Finally, the performance of the delayed teleoperation system is evaluated through tests where a human operator drives a 3D simulator as well as a mobile robot for pushing objects.

  13. A numerical simulation of wheel spray for simplified vehicle model based on discrete phase method

    Directory of Open Access Journals (Sweden)

    Xingjun Hu

    2015-07-01

    Full Text Available Road spray greatly affects vehicle body soiling and driving safety. The study of road spray has attracted increasing attention. In this article, computational fluid dynamics software with widely used finite volume method code was employed to investigate the numerical simulation of spray induced by a simplified wheel model and a modified square-back model proposed by the Motor Industry Research Association. Shear stress transport k-omega turbulence model, discrete phase model, and Eulerian wall-film model were selected. In the simulation process, the phenomenon of breakup and coalescence of drops were considered, and the continuous and discrete phases were treated as two-way coupled in momentum and turbulent motion. The relationship between the vehicle external flow structure and body soiling was also discussed.

  14. Brain activity during driving with distraction: an immersive fMRI study

    Directory of Open Access Journals (Sweden)

    Tom A Schweizer

    2013-02-01

    Full Text Available Introduction: Non-invasive measurements of brain activity have an important role to play in understanding driving ability. The current study aimed to identify the neural underpinnings of human driving behavior by visualizing the areas of the brain involved in driving under different levels of demand, such as driving while distracted or making left turns at busy intersections. Methods: To capture brain activity during driving, we placed a driving simulator with a fully functional steering wheel and pedals in a 3.0 Tesla functional magnetic resonance imaging (fMRI system. To identify the brain areas involved while performing different real-world driving maneuvers, participants completed tasks ranging from simple (right turns to more complex (left turns at busy intersections. To assess the effects of driving while distracted, participants were asked to perform an auditory task while driving analogous to speaking on a hands-free device and driving. Results: A widely distributed brain network was identified, especially when making left turns at busy intersections compared to more simple driving tasks. During distracted driving, brain activation shifted dramatically from the posterior, visual and spatial areas to the prefrontal cortex. Conclusions: Our findings suggest that the distracted brain sacrificed areas in the posterior brain important for visual attention and alertness to recruit enough brain resources to perform a secondary, cognitive task. The present findings offer important new insights into the scientific understanding of the neuro-cognitive mechanisms of driving behavior and lay down an important foundation for future clinical research.

  15. Torque blending and wheel slip control in EVs with in-wheel motors

    Science.gov (United States)

    de Castro, Ricardo; Araújo, Rui E.; Tanelli, Mara; Savaresi, Sergio M.; Freitas, Diamantino

    2012-01-01

    Among the many opportunities offered by electric vehicles (EVs), the design of power trains based on in-wheel electric motors represents, from the vehicle dynamics point of view, a very attractive prospect, mainly due to the torque-vectoring capabilities. However, this distributed propulsion also poses some practical challenges, owing to the constraints arising from motor installation in a confined space, to the increased unsprung mass weight and to the integration of the electric motor with the friction brakes. This last issue is the main theme of this work, which, in particular, focuses on the design of the anti-lock braking system (ABS). The proposed structure for the ABS is composed of a tyre slip controller, a wheel torque allocator and a braking supervisor. To address the slip regulation problem, an adaptive controller is devised, offering robustness to uncertainties in the tyre-road friction and featuring a gain-scheduling mechanism based on the vehicle velocity. Further, an optimisation framework is employed in the torque allocator to determine the optimal split between electric and friction brake torque based on energy performance metrics, actuator constraints and different actuators bandwidth. Finally, based on the EV working condition, the priorities of this allocation scheme are adapted by the braking supervisor unit. Simulation results obtained with the CarSim vehicle model, demonstrate the effectiveness of the overall approach.

  16. Study on Power Switching Process of a Hybrid Electric Vehicle with In-Wheel Motors

    Directory of Open Access Journals (Sweden)

    Shaohua Wang

    2016-01-01

    Full Text Available Hybrid electric vehicles with in-wheel motors (IWM achieve a variety of driving modes by two power sources—the engine and the IWM. One of the critical problems that exists in such vehicle is the different transient characteristics between the engine and the IWM. Therefore, switching processes between the power sources have noteworthy impacts on vehicle dynamics and driving performance. For the particular switching process of the pure electric mode to the engine driving mode, a specific control strategy coordinating clutch torque, motor torque, and engine torque was proposed to solve drivability issues caused by inconsistent responses of different power sources during the mode transition. The specific switching process could be described as follows: the engine was started by IWM with the clutch serving as a key enabling actuator, dynamic torque compensation through IWM was implemented after engine started, and, meanwhile, engine speed was controlled to track the target speed through the closed loop PID control strategy. The bench tests results showed that the vehicle jerk caused during mode switching was reduced and fast and smooth mode switching was realized, which leads to the improvement of vehicle’s riding comfort.

  17. Assessment of Lateral Driving Stability of Automobiles Passing by the Pylon Zone under Cross Wind

    Directory of Open Access Journals (Sweden)

    Dalei Wang

    2012-08-01

    Full Text Available In order to explore the reason of lateral instability of automobile passing by the pylon zone of cablesupported bridge under cross wind, a new evaluation method of lateral driving stability of automobile considering alternative cross wind is established based on multi-objective driving stability criteria and subjective assessment. Typical driving control process and dynamic response of automobile passing by the pylon zone is given by numerical simulation based on steering wheel fixed-control model and straight driving ideal-driver model. Finally, taking a medium-size commercial bus as an example, the reason of its lateral instability is interpreted and the influence of cross wind speed and driving speed on its lateral driving stability is shown by parameter study.

  18. Driving After a Stroke

    Science.gov (United States)

    ... Inspirational Stories Stroke Heroes Among Us Driving After Stroke Updated:Jul 23,2015 Can I drive after ... more tips for daily living . Let's Talk About Stroke Fact Sheets Our stroke fact sheets cover treatments, ...

  19. Electric Vehicle - Economical driving

    DEFF Research Database (Denmark)

    Jensen, VCE, Steen V.; Schøn, Henriette

    1999-01-01

    Instruct the reader in getting most satisfaction out of an EV, especially concerning driving and loading.......Instruct the reader in getting most satisfaction out of an EV, especially concerning driving and loading....

  20. Dementia and driving

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000028.htm Dementia and driving To use the sharing features on ... please enable JavaScript. If your loved one has dementia , deciding when they can no longer drive may ...

  1. Measurement of the air boundary layer on the periphery of a rotating grinding wheel using LDA

    Energy Technology Data Exchange (ETDEWEB)

    Wu, H [AMTReL, GERI, Liverpool John Moores University, Liverpool (United Kingdom); Lin, B [School of Mechanical Engineering, Tianjin University, Tianjin (China); Cai, R [AMTReL, GERI, Liverpool John Moores University, Liverpool (United Kingdom); Morgan, M N [AMTReL, GERI, Liverpool John Moores University, Liverpool (United Kingdom)

    2007-07-15

    In this paper, the velocity profile of the air boundary layer around a rotating grinding wheel was measured using the Laser Doppler Anemometry technique. Experimental results show that the tangential velocity of the air decreases greatly with increasing distance from the wheel surface. The distribution of the tangential velocity is also found to be almost uniform near to the centre of the wheel width, and decreases greatly as the wheel edge is approached. Generally, the radial velocity of air in the area close to the wheel surface is small, and then increases with the increasing distance from wheel surface.

  2. Gear bearing drive

    Science.gov (United States)

    Weinberg, Brian (Inventor); Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor)

    2011-01-01

    A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.

  3. ELASTIC NONLINEAR DYNAMICS OF MOTION OF SLIDE OF VERTICAL TURNING MACHINE FOR WORKING OF SOLID-ROLLED RAILWAY WHEELS

    Directory of Open Access Journals (Sweden)

    R. P. Pogrebnyak

    2017-08-01

    Full Text Available Purpose. The article is aimed to determine the conditions of a dynamic error formation of contour machine cutting of surface of the real railway wheel flange by the cup-tip tool and propose the ways of reducing the errors. Methodology. The problem was solved by the creation of dynamic nonlinear and elastic calculation model with further modeling of its loading by the external force factors. The values of forces were obtained by analytical and experimental methods. The calculation scheme of the equilibrium support is a nonlinear two-mass system, a dynamic model of slide - single-mass with one degree of freedom. The basis of the mathematical description of technological loads is the results of factory experiments, as well as analytical generalizations obtained as a result of the comparison of several schemes of the formation of the wheel flange. Analytical determination of the components of the cutting force takes into account the changes in the kinematic parameters of the cutting mode when the profiling is done using a shaped tool. Findings. During processing of the wheel flange the radial and axial components of the cutting forces that load slide and slide-block of machine are alternating. There are conditions in drive of slide and slide-block when the gaps appear, and it is possible at any profile geometry of the wheel. The peculiarities of loading of the slide and slide-block forming a flange (with biharmonic allowance cause the occurrence of the processing areas where the gaps increase many times in drives of mechanical transmissions and error of forms increases. The dynamic system of the drive is quite tough and high-frequency and it is sensitive to the presence of gaps. Originality. The author created elastic nonlinear dynamic models of support and slide. In accordance with the model it is written and solved equations of motion of the masses and loading of the connections. The conditions of the stable motion were found. Practical value. It

  4. Simple Driving Techniques

    DEFF Research Database (Denmark)

    Rosendahl, Mads

    2002-01-01

    -like language. Our aim is to extract a simple notion of driving and show that even in this tamed form it has much of the power of more general notions of driving. Our driving technique may be used to simplify functional programs which use function composition and will often be able to remove intermediate data......Driving was introduced as a program transformation technique by Valentin Turchin in some papers around 1980. It was intended for the programming language REFAL and used in metasystem transitions based on super compilation. In this paper we present one version of driving for a more conventional lisp...

  5. High performance AC drives

    CERN Document Server

    Ahmad, Mukhtar

    2010-01-01

    This book presents a comprehensive view of high performance ac drives. It may be considered as both a text book for graduate students and as an up-to-date monograph. It may also be used by R & D professionals involved in the improvement of performance of drives in the industries. The book will also be beneficial to the researchers pursuing work on multiphase drives as well as sensorless and direct torque control of electric drives since up-to date references in these topics are provided. It will also provide few examples of modeling, analysis and control of electric drives using MATLAB/SIMULIN

  6. 一种星轮式爬楼梯电动轮椅设计%Design of a Star Wheel Power-Driven Stair-Climbing Wheelchair

    Institute of Scientific and Technical Information of China (English)

    王占礼; 孟祥雨; 陈延伟

    2012-01-01

    A three star wheels stairs-climbing electric wheelchair is designed.One of the star wheels is wheel motor.The three star wheels stairs-climbing device climbs up the obstacles,with the wheel motor driving on the ground, which realizes the organic combination of climb building and the electric wheelchair function.The Star wheel stair-climbing device is the key to it.The stair-climbing device and its walking mechanisms was designed by in梔epth study, with fully consideration of the requirements of structure,size and climb power,and security of the stair-climbing device.The results of analysis of performance of wheel chair show that stair-climbing wheel chair reaches the design requirements and has the advantages of safety, stability,simple operation and easy control.%设计了一款三星轮式爬楼梯电动轮椅,其中一个星轮为轮毂电机.采用三星轮机构实现爬楼越障,采用轮毂电机驱动轮椅平地行驶,实现了爬楼功能和电动轮椅功能的有机结合.爬升装置是爬楼梯轮椅的关键,在深入研究爬楼梯轮椅工作机理基础上,充分考虑爬楼梯轮椅爬升装置的结构和尺寸以及爬升功率、安全性等要求,在对爬升装置设计的同时还对轮椅行走环节进行了设计.经过性能分析,设计的爬楼梯轮椅达到了功能要求,并具有乘坐安全、爬楼梯稳定、控制容易以及操作简单等特点.

  7. Modeling and Analysis of Linearized Wheel-Rail Contact Dynamics

    Directory of Open Access Journals (Sweden)

    Zulfiqar Ali Soomro

    2014-07-01

    Full Text Available The dynamics of the railway vehicles are nonlinear and depend upon several factors including vehicle speed, normal load and adhesion level. The presence of contaminants on the railway track makes them unpredictable too. Therefore in order to develop an effective control strategy it is important to analyze the effect of each factor on dynamic response thoroughly. In this paper a linearized model of a railway wheel-set is developed and is later analyzed by varying the speed and adhesion level by keeping the normal load constant. A wheel-set is the wheel-axle assembly of a railroad car. Patch contact is the study of the deformation of solids that touch each other at one or more points

  8. Railway Wheel Flat Detection Based on Improved Empirical Mode Decomposition

    Directory of Open Access Journals (Sweden)

    Yifan Li

    2016-01-01

    Full Text Available This study explores the capacity of the improved empirical mode decomposition (EMD in railway wheel flat detection. Aiming at the mode mixing problem of EMD, an EMD energy conservation theory and an intrinsic mode function (IMF superposition theory are presented and derived, respectively. Based on the above two theories, an improved EMD method is further proposed. The advantage of the improved EMD is evaluated by a simulated vibration signal. Then this method is applied to study the axle box vibration response caused by wheel flats, considering the influence of both track irregularity and vehicle running speed on diagnosis results. Finally, the effectiveness of the proposed method is verified by a test rig experiment. Research results demonstrate that the improved EMD can inhibit mode mixing phenomenon and extract the wheel fault characteristic effectively.

  9. Calibration procedure of measuring system for vehicle wheel load estimation

    Science.gov (United States)

    Kluziewicz, M.; Maniowski, M.

    2016-09-01

    The calibration procedure of wheel load measuring system is presented. Designed method allows estimation of selected wheel load components while the vehicle is in motion. Mentioned system is developed to determine friction forces between tire and road surface, basing on measured internal reaction forces in wheel suspension mechanism. Three strain gauge bridges and three-component piezoelectric load cell are responsible for internal force measurement in suspension components, two wire sensors are measuring displacements. External load is calculated via kinematic model of suspension mechanism implemented in Matlab environment. In the described calibration procedure, internal reactions are measured on a test stand while the system is loaded by a force of known direction and value.

  10. Model Design for Water Wheel Control System of Heumgyeonggaknu

    Science.gov (United States)

    Kim, Sang Hyuk; Ham, Seon Young; Lee, Yong Sam

    2016-03-01

    Heumgyeonggaknu (????) is powered by a water-hammering-type water wheel. The technique that maintains the constant speed of the water wheel is assumed to be the one used in the Cheonhyeong (???) apparatus in Shui Yun Yi Xiang Tai (???) made by the Northern Song (??) dynasty in the 11th century. We investigated the history of the development and characteristics of the Cheonhyeong apparatus, and we analyzed ways to transmit the power of Heumgyeonggaknu. In addition, we carried out a conceptual design to systematically examine the power control system. Based on the conceptual design, we built a model for a water wheel control system that could be used in experiments by drawing a 3D model and a basic design.

  11. Pot Plus Booze: A Deadly Mix Behind the Wheel

    Science.gov (United States)

    ... past two decades," Li said. "Countermeasures targeting both drunk driving and drugged driving are needed to improve traffic ... and Human Services. More Health News on Alcohol Impaired Driving Marijuana Recent Health News Related MedlinePlus Health Topics ...

  12. Engineering report. Part 1: NASA wheel air seal development for space shuttle type environmental requirements

    Science.gov (United States)

    1973-01-01

    The sealing techniques are studied for existing aircraft wheel-tire designs to meet the hard vacuum .00001 torr and cold temperature -65 F requirements of space travel. The investigation covers the use of existing wheel seal designs.

  13. IN SITU TRUING/DRESSING OF DIAMOND WHEEL FOR PRECISION GRINDING

    Institute of Scientific and Technical Information of China (English)

    WAN Daping; WANG Yan; HU Dejin

    2008-01-01

    An application for achieving on-machine truing/dressing and monitoring of diamond wheel is dealt with in dry grinding. A dry electrical discharge (ED) assisted truing and dressing method is adopted in preparation of diamond grinding wheels. Effective and precise truing/dressing of a diamond wheel is carried out on a CNC curve grinding machine by utilizing an ED assisted diamond dresser. The dressed wheel is monitored online by a CCD vision system. It detects the topography changes of a wheel surface. The wear condition is evaluated by analyzing the edge deviation of a wheel image. The benefits of the proposed methods are confirmed by the grinding experiments. The designed truing/dressing device has high material removal rate, low dresser wear, and hence guarantees a desired wheel surface. Real-time monitoring of the wheel profile facilitates determining the optimum dressing amount, dressing interval, and the compensation error.

  14. Development and application of resilient wheels in urban rail transit vehicle

    Directory of Open Access Journals (Sweden)

    Juan WEN

    Full Text Available Urban rail transit vehicles have been more and more attractive to people as a kind of fast, comfortable, energy-saving, environmental protection and safe transportation. But because of the vehicle noise and vibration, urban rail vehicles also face severe challenges. The research of resilient wheels has been continuously developed and improved. Based on the review of development background and structure sorts of resilient wheels, the advantages of resilient wheels are described, and the research status of noise and vibration reducing, infinite element strength analysis, vehicle dynamic analysis and the wheel-rail wear of resilient wheels are discussed. Taking the low-floor LRVs (light rail vehicles in domestic and overseas as example, the development and application of the resilient wheels in city rail transit is described, and the application prospects of the resilient wheels in LRVs in domestic and the future research direction of elastic wheel are discussed.

  15. INFLUENCE OF WHEEL STRUCTURAL PARAMETERS ON MACHINING ACCURACY OF ULTRA-PRECISION PLANE HONING

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new idea for designing wheel patterns is presented so as to solve the problems about machining accuracy ofworkpiece and wear of honing wheel in ultra-precision plane honing. The influence factors on motion principle and pat-tern structures are analyzed and optimization machining parameters are obtained. By calculating effective cutting lengthon the surface of workpiece cut by wheel's abrasive and the orbit of one point on the surface of workpiece contactingwith wheel, the wear coefficient of different kinds of wheels and accuracy coefficient of workpiece machined by corre-sponding wheels are obtained. Furthermore, the simulation results show that the optimal pattern structure of wheel turnsout to have lower wheel wear and higher machining accuracy.

  16. ANALYSIS OF POSSIBLE BLOCK SCHEMATIC DIAGRAMS OF ELECTROMECHANICAL TRANSMISSIONS FOR WHEEL TRACTORS

    Directory of Open Access Journals (Sweden)

    A. Kliuchnikov

    2012-01-01

    Full Text Available The paper considers advantages of stepless electromechanical transmissions. Possible diagrams of their development for application at wheel tractors have been presented in the paper. schemes for wheel tractors applications Presented and analyzed. 

  17. PARAMETER MATCHING OF INTERNAL COMBUSTION ENGINE AND ELECTROMECHANICAL POWER TRAIN OF WHEEL TRACTOR

    Directory of Open Access Journals (Sweden)

    A. Kliuchnikov

    2012-01-01

    Full Text Available The paper considers stepless electromechanical power train of a wheel tractor. Methodology for parameter matching of electromechanical transmission and internal combustion engine for their optimum performance as part of a power wheel tractor unit. 

  18. Simulation of the ATLAS New Small Wheel Trigger Sysmtem

    CERN Document Server

    Saito, Tomoyuki; The ATLAS collaboration

    2017-01-01

    The instantaneous luminosity of the Large Hadron Collider (LHC) at CERN will be increased up to a factor of five with respect to the original design value to explore higher energy scale. In order to benefit from the expected high luminosity performance, the first station of the ATLAS muon end-cap Small Wheel system will be replaced by a New Small Wheel (NSW) detector. The NSW provide precise track segment information to the muon Level-1 trigger to reduce fake triggers. This contribution will summarize a detail of the NSW trigger decision system, track reconstruction algorithm implemented into the trigger processor and results of performance studies on the trigger system.

  19. Mono- and multilayers of molecular spoked carbazole wheels on graphite

    Directory of Open Access Journals (Sweden)

    Stefan-S. Jester

    2014-11-01

    Full Text Available Self-assembled monolayers of a molecular spoked wheel (a shape-persistent macrocycle with an intraannular spoke/hub system and its synthetic precursor are investigated by scanning tunneling microscopy (STM at the liquid/solid interface of 1-octanoic acid and highly oriented pyrolytic graphite. The submolecularly resolved STM images reveal that the molecules indeed behave as more or less rigid objects of certain sizes and shapes – depending on their chemical structures. In addition, the images provide insight into the multilayer growth of the molecular spoked wheels (MSWs, where the first adlayer acts as a template for the commensurate adsorption of molecules in the second layer.

  20. Fabrication of micro gear wheels by micropowder injection molding

    Institute of Scientific and Technical Information of China (English)

    Haiqing Yin; Xuanhui Qu; Chengchang Jia

    2008-01-01

    The micropowder injection molding technology was investigated to fabricate the microsized gear wheels on a conventional injection molding machine. The feedstock comprised of carbonyl ferrum powder and a wax-based thermoplastic binder. Microinjection molding was fulfilled at about 423 K under 100 MPa. The heating system was applied to the die to improve the fluidity of the feedstock and subsequently the cooling system was used to enhance the strength of the green compacts after injection by decreasing the temperature of the die. The gear wheels were realized successfully with their addendum circle diameter ranging from 800 to 200 m and with the center hole as small as 60 μtm.

  1. A Star-Wheel Stair-Climbing Wheelchair

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li; WU Bo; JIN Ai-min; JIANG Shi-hong; ZHENG Yu-fei; ZHANG Shuai

    2014-01-01

    In order to achieve a wheelchair climb stairs function, this paper designs a star-wheel stair-climbing mechanism. Through the effect of the lock coupling, the star-wheel stair-climbing mechanism is formed to be fixed axis gear train or planetary gear train achieving flat-walking and stair-climbing functions. Crossing obstacle analysis obtains the maximum height and minimum width of obstacle which the wheelchair can cross. Stress-strain analysis in Solidworks simulation is performed to verify material strength.

  2. Metering Wheel-Wire Track Wire Boom Deployment Mechanism

    Science.gov (United States)

    Granoff, Mark S.

    2014-01-01

    The NASA MMS Spin Plane Double Probe (SDP) Deployer utilizes a helical path, rotating Metering Wheel and a spring loaded Wire "Holding" Track to pay out a "fixed end" 57 meter x 1.5 mm diameter Wire Boom stored between concentric storage cylinders. Unlike rotating spool type storage devices, the storage cylinders remain stationary, and the boom wire is uncoiled along the length of the cylinder via the rotation of the Metering Wheel. This uncoiling action avoids the need for slip-ring contacts since the ends of the wire can remain stationary. Conventional fixed electrical connectors (Micro-D type) are used to terminate to operational electronics.

  3. Steering Control of Wheeled Armored Vehicle with Brushless DC Motor

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Considering the steering characters of one type of wheeled armored vehicle, a brushless direct current (DC) motor is adapted as the actuator for steering control. After investigating the known algorithms, one kind of algorithm, which combines the fuzzy logic control with the self-adapting PID control and the startup and pre-brake control, is put forward. Then a test-bed is constructed, and an experiment is conducted. The result of experiment confirms the validity of this algorithm in steering control of wheeled armored vehicle with brushless DC motor.

  4. 14 CFR Appendix D to Part 23 - Wheel Spin-Up and Spring-Back Loads

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Wheel Spin-Up and Spring-Back Loads D.... D Appendix D to Part 23—Wheel Spin-Up and Spring-Back Loads D23.1 Wheel spin-up loads. (a) The... spring-back of the landing gear and adjacent structure at the instant just after the wheels come up...

  5. Design Optimization of a Mecanum Wheel to Reduce Vertical Vibrations by the Consideration of Equivalent Stiffness

    OpenAIRE

    Jong-Jin Bae; Namcheol Kang

    2016-01-01

    Mecanum wheels are capable of moving a vehicle to any direction instantaneously by the combination of independent wheel rotations. Because the mecanum wheel is composed of a hub and rollers, however, it has unavoidable drawbacks such as vertical and horizontal vibrations due to the sequential contacts between rollers and ground. In order to investigate the dynamic characteristics of a mecanum wheel, we made a prototype and performed experiments to measure the vertical vibrations. Interestingl...

  6. Design of a robot for in-pipe inspection using omnidirectional wheels and active stabilization

    NARCIS (Netherlands)

    Dertien, Edwin; Mozaffari Foumashi, Mohammad; Pulles, Kees; Stramigioli, Stefano

    2014-01-01

    This paper discusses the design of a vehicle for in-pipe inspection using omnidirectional wheels and active stabilizing control. A novel propulsion mechanism is discussed using omnidirectional wheels (or omni-wheels) is presented which allows direct control of the orientation in the pipe. This paper

  7. Investigation of wear mechanism of tread during operation of railway wheels

    Directory of Open Access Journals (Sweden)

    Svetlana GUBENKO

    2012-01-01

    Full Text Available Causes of wear particles formation on railway wheels tread were investigated. Structural factors connecting with plastic deformation, formation of “white layer”, and also with non-metallic inclusions and corrosive products of wheel steel, defining wear of railway wheels tread during operation were fixed.

  8. Learning to Drive Safely: Reasonable Expectations and Future Directions for the Learner Period

    Directory of Open Access Journals (Sweden)

    Bruce Simons-Morton

    2016-10-01

    Full Text Available The young driver problem is typified by high crash rates early in licensure that decline with experience, but are higher initially and decline more slowly for the youngest novices. Despite considerable effort, only Graduated Driver Licensing System (GDLS policies have been shown to improve novice young driver safety outcomes. Unfortunately, GDLS policies are mostly limited to countries with a relatively young licensure age. Meanwhile, it is not entirely clear how GDLS and other young driver transportation safety efforts, including driver training and testing, supervised practice and parental management of young drivers, can best be configured. Notably, professional training can foster improvements in vehicle management skills that are necessary, but do not assure safe driving behavior. Substantial recent research has focused on training methods to improve driving skills, but the safety benefits of driver training have not been established. While prolonged practice driving increases experience and provides supervisors with opportunities to prepare novices for independent driving, the transition to independent driving challenges novices to employ, on their own, poorly-mastered skills under unfamiliar and complex driving conditions. Licensing policies and parental management practices can limit the complexity of driving conditions while novices gain needed driving experience. Nevertheless, an emerging body of literature suggests that future advances in training and supervision of novice teenage drivers might best focus on the translation of learning to independent driving by fostering safe driving attitudes and norms, judgment, dedicated attention to driving tasks and self-control at the wheel.

  9. Lectures on magnetohydrodynamical drives

    Science.gov (United States)

    Loigom, Villem

    The paper deals with nonconventional types of electrical machines and drives - magnetohydrodynamical (MHD) machines and drives. In cardinal it is based on the research conducted with participation of the author in Tallinn Technical University at the Institute of Electrical Drives and Power Electronics, where the use of magnetohydrodynamical motors and drives in the metallurgical and casting industries have been studied for a long time. Major research interests include the qualities and applications of the induction MHD-drives for set in the motion (pumping, turning, dosing, mixing, etc.) non-ferrous molten metals like Al, Mg, Sn, Pb, Na, K, and their alloys. The first part of the paper describes induction MHD motors and their electrohydraulical qualities. In the second part energy conversion problems are described. Also, on the basis of the analogy between electromechanical and electrohydraulical phenomenas, static and dynamic qualities of MHD drives with induction MHD machines are discussed.

  10. 前桥摆转式四轮底盘转向系统的转向机理研究%Research on the Steering Theory of Front Axle Swing Sowing Four-wheel Chassis

    Institute of Scientific and Technical Information of China (English)

    吕莹; 张静; 李志伟

    2016-01-01

    四轮底盘在小地块水田作业时,减少地头空行转弯时间是提高作业时间利用率的重要环节。为实现四轮底盘小半径转弯,以提高水田播插底盘作业率为主要研究目标,对四轮底盘在90°、180°等不同转弯形式下进行分析,得出适合小地块水稻播插作业时以较小转弯半径的转弯方式;前桥摆转四轮底盘在转向时,通过控制前桥驱动轮的转动,使前驱动桥主动围绕着转向装置转动,可以带动底盘以任意角度转向。采用ADAMS软件对四轮底盘后轮轨迹进行模拟,在确保后轮完全不吃入已完成作业区的倒U转弯方式的情况下,提出设计前桥摆转式四轮底盘转向系统的可行性。%Four-wheel chassis when working in a small piece of paddy field, reduce blank line turning time is an important link in work utilization rate operation time. In this paper, in order to realize four-wheel chassis small turning radius, increase the paddy field on chassis operation efficiency as the main research target, 90°, 180° in the four-wheel chassis under different forms of turning modeling analysis, and concluded that suitable turning way of smaller turning radius for small plot rice sowing operations ; When the front axle Swing four-wheel chassis steering, By controlling the rotation of the front drive axle, to the front drive axle can rotate active around the steering device, and drive the chassis steering in an arbitrary Angle; Through ADAMS soft-ware for simulating four-wheel chassis rear wheel track, and ensuring the rear wheels do not enter that the as-signments section has been completed, put forward to design front axle pendulum type four-wheel chassis steer-ing system operability.

  11. Universal Drive Train Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This vehicle drive train research facility is capable of evaluating helicopter and ground vehicle power transmission technologies in a system level environment. The...

  12. Development of Trigger and Readout Electronics for the ATLAS New Small Wheel Detector Upgrade

    CERN Document Server

    Zhu, Junjie; The ATLAS collaboration

    2017-01-01

    The planned Phase-I and Phase-II upgrades of the LHC accelerator drastically impacts the ATLAS trigger and trigger rates. A replacement of the ATLAS innermost endcap muon station with a new small wheel (NSW) detector is planned for the second long shutdown period of 2019 - 2020. This upgrade will allow us to maintain a low pT threshold for single muon and excellent tracking capability even after the High-Luminosity LHC upgrade. The NSW detector will feature two new detector technologies, Resistive Micromegas and small-strip Thin Gap Chambers. Both detector technologies will provide trigger and tracking primitives. The total number of trigger and readout channels is about 2.4 millions, and the overall power consumption is expected to be about 75 kW. The electronics design will be implemented in some 8000 front-end boards including the design of four custom front-end ASICs capable to drive trigger and tracking primitives with high speed sterilizers to drive trigger candidates to the backend trigger processor sy...

  13. Towards a Continuous Biometric System Based on ECG Signals Acquired on the Steering Wheel

    Directory of Open Access Journals (Sweden)

    João Ribeiro Pinto

    2017-09-01

    Full Text Available Electrocardiogram signals acquired through a steering wheel could be the key to seamless, highly comfortable, and continuous human recognition in driving settings. This paper focuses on the enhancement of the unprecedented lesser quality of such signals, through the combination of Savitzky-Golay and moving average filters, followed by outlier detection and removal based on normalised cross-correlation and clustering, which was able to render ensemble heartbeats of significantly higher quality. Discrete Cosine Transform (DCT and Haar transform features were extracted and fed to decision methods based on Support Vector Machines (SVM, k-Nearest Neighbours (kNN, Multilayer Perceptrons (MLP, and Gaussian Mixture Models - Universal Background Models (GMM-UBM classifiers, for both identification and authentication tasks. Additional techniques of user-tuned authentication and past score weighting were also studied. The method’s performance was comparable to some of the best recent state-of-the-art methods (94.9% identification rate (IDR and 2.66% authentication equal error rate (EER, despite lesser results with scarce train data (70.9% IDR and 11.8% EER. It was concluded that the method was suitable for biometric recognition with driving electrocardiogram signals, and could, with future developments, be used on a continuous system in seamless and highly noisy settings.

  14. Towards a Continuous Biometric System Based on ECG Signals Acquired on the Steering Wheel.

    Science.gov (United States)

    Pinto, João Ribeiro; Cardoso, Jaime S; Lourenço, André; Carreiras, Carlos

    2017-09-28

    Electrocardiogram signals acquired through a steering wheel could be the key to seamless, highly comfortable, and continuous human recognition in driving settings. This paper focuses on the enhancement of the unprecedented lesser quality of such signals, through the combination of Savitzky-Golay and moving average filters, followed by outlier detection and removal based on normalised cross-correlation and clustering, which was able to render ensemble heartbeats of significantly higher quality. Discrete Cosine Transform (DCT) and Haar transform features were extracted and fed to decision methods based on Support Vector Machines (SVM), k-Nearest Neighbours (kNN), Multilayer Perceptrons (MLP), and Gaussian Mixture Models - Universal Background Models (GMM-UBM) classifiers, for both identification and authentication tasks. Additional techniques of user-tuned authentication and past score weighting were also studied. The method's performance was comparable to some of the best recent state-of-the-art methods (94.9% identification rate (IDR) and 2.66% authentication equal error rate (EER)), despite lesser results with scarce train data (70.9% IDR and 11.8% EER). It was concluded that the method was suitable for biometric recognition with driving electrocardiogram signals, and could, with future developments, be used on a continuous system in seamless and highly noisy settings.

  15. STABILITY OF WHEELED VEHICLES AS COMPLEX OPERATIONAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    N. Artemov

    2011-01-01

    Full Text Available Different views on the definition of «stability of wheeled vehicles» are considered and the author’s own definition is offered. A version of the structure of stability properties as a complex op-erational property is offered.

  16. A Switching Controller System for a Wheeled Mobile Robot

    Institute of Scientific and Technical Information of China (English)

    Masanori Sato; Atushi Kanda; Kazuo Ishii

    2007-01-01

    A wheeled mobile mechanism with a passive and/or active linkage mechanism for rough terrain environment is developed and evaluated. The wheeled mobile mechanism which has high mobility in rough terrain needs sophisticated system to adapt various environments.We focus on the development of a switching controller system for wheeled mobile robots in rough terrain. This system consists of two sub-systems: an environment recognition system using link angles and an adaptive control system. In the environment recognition system, we introduce a Self-Organizing Map (SOM) for clustering link angles. In the adaptive controllers, we introduce neural networks to calculate the inverse model of the wheeled mobile robot.The environment recognition system can recognize the environment in which the robot travels, and the adjustable controllers are tuned by experimental results for each environment. The dual sub-system switching controller system is experimentally evaluated. The system recognizes its environment and adapts by switching the adjustable controllers. This system demonstrates superior performance to a well-tuned single PID controller.

  17. The TASC Wheel Supports a Honey Bee Challenge

    Science.gov (United States)

    Seeley, Claire

    2011-01-01

    The concept of TASC (Thinking Actively in a Social Context) was created by Belle Wallace (Wallace et al., 1993) as a model that can be used to nurture and develop thinking skills. As children work through the TASC wheel, the teacher has a very good opportunity to facilitate explicit conversations about thinking. This allows the children to grow in…

  18. Development of a Large Scale, High Speed Wheel Test Facility

    Science.gov (United States)

    Kondoleon, Anthony; Seltzer, Donald; Thornton, Richard; Thompson, Marc

    1996-01-01

    Draper Laboratory, with its internal research and development budget, has for the past two years been funding a joint effort with the Massachusetts Institute of Technology (MIT) for the development of a large scale, high speed wheel test facility. This facility was developed to perform experiments and carry out evaluations on levitation and propulsion designs for MagLev systems currently under consideration. The facility was developed to rotate a large (2 meter) wheel which could operate with peripheral speeds of greater than 100 meters/second. The rim of the wheel was constructed of a non-magnetic, non-conductive composite material to avoid the generation of errors from spurious forces. A sensor package containing a multi-axis force and torque sensor mounted to the base of the station, provides a signal of the lift and drag forces on the package being tested. Position tables mounted on the station allow for the introduction of errors in real time. A computer controlled data acquisition system was developed around a Macintosh IIfx to record the test data and control the speed of the wheel. This paper describes the development of this test facility. A detailed description of the major components is presented. Recently completed tests carried out on a novel Electrodynamic (EDS) suspension system, developed by MIT as part of this joint effort are described and presented. Adaptation of this facility for linear motor and other propulsion and levitation testing is described.

  19. "Walking" Along a Free Rotating Bicycle Wheel (Round and Round)

    CERN Document Server

    Guemez, Julio

    2016-01-01

    We describe the kinematics, dynamics and also some energetic issues related to the Marta mouse motion when she walks on top of a horizontal bicycle wheel, which is free to rotate like a merry-to-go round, as presented recently by Paul Hewitt in the Figuring Physics section of this magazine.

  20. "Walking" Along a Free Rotating Bicycle Wheel (Round and Round)

    Science.gov (United States)

    Güémez, J.; Fiolhais, M.

    2015-01-01

    We describe the kinematics, dynamics, and also some energy issues related to Marta mouse's motion when she walks on top of a horizontal bicycle wheel, which is free to rotate like a merry-go-round, as presented recently by Paul Hewitt in the "Figuring Physics" section of this journal. The situation is represented in Fig. 1, which was…

  1. Design of wheel-type walking-assist device

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Seung Ho; Kim, Seung Ho; Kim, Chang Hoi; Seo, Yong Chil; Jung, Kyung Min; Lee, Sung Uk

    2006-03-15

    In this research, a outdoor wheel-type walking-assist device is developed to help an elder having a poor muscular strength at legs for walking, sitting and standing up easily at outdoors, and also for going and downing stairs. In conceptually designing, the environments of an elder's activity, the size of an elder's body and a necessary function of helping an elder are considered. This device has 4 wheels for stability. When an elder walks in incline plane with the proposed device, a rear-wing is rotated to keep the supporting device horizontal, regardless of an angle of inclination. A height-controlling device, which can control the height of the supporting device for adjusting an elder's height, is varied vertically to help an elder to sit and stand-up easily. Moreover, a outdoor wheel-type walking-assist device is conceptually designed and is made. In order to design it, the preview research is investigated firstly. On the basis of the proposed walking-assist device, the outdoor walking-assist device is designed and made. The outdoor wheel-type walking-assist device can go and down stairs automatically. This device go up and down the stair of having maximum 20cm height and an angle of 25 degrees with maximum 4 sec/stairs speed, and move at flatland with 60cm/sec speed.

  2. Soft Legged Wheel-Based Robot with Terrestrial Locomotion Abilities

    Directory of Open Access Journals (Sweden)

    Ali Sadeghi

    2016-12-01

    Full Text Available In recent years robotics has been influenced by a new approach, soft-robotics, bringing the idea that safe interaction with user and more adaptation to the environment can be achieved by exploiting easily deformable materials and flexible components in the structure of robots. In 2016, the soft-robotics community has promoted a new robotics challenge, named RoboSoft Grand Challenge, with the aim of bringing together different opinions on the usefulness and applicability of softness and compliancy in robotics. In this paper we describe the design and implementation of a terrestrial robot based on two soft legged wheels. The tasks predefined by the challenge were set as targets in the robot design, which finally succeeded to accomplish all the tasks. The wheels of the robot can passively climb over stairs and adapt to slippery grounds using two soft legs embedded in their structure. The soft legs, fabricated by integration of soft and rigid materials and mounted on the circumference of a conventional wheel, succeed to enhance its functionality and easily adapt to unknown grounds. The robot has a semi stiff tail that helps in the stabilization and climbing of stairs. An active wheel is embedded at the extremity of the tail in order to increase the robot maneuverability in narrow environments. Moreover two parallelogram linkages let the robot to reconfigure and shrink its size allowing entering inside gates smaller than its initial dimensions.

  3. 76 FR 18781 - Certain Steel Wheels From China

    Science.gov (United States)

    2011-04-05

    ....8 of the Commission's rules, as amended, 67 FR 68036 (November 8, 2002). Even where electronic... (C) of the Commission's Handbook on Electronic Filing Procedures, 67 FR 68168, 68173 (November 8... COMMISSION Certain Steel Wheels From China AGENCY: United States International Trade Commission....

  4. Characterizing the Performance of the Wheel Electrostatic Spectrometer

    Science.gov (United States)

    Johansen, Michael R.; Mackey, P. J.; Holbert, E.; Calle, C. I.; Clements, J. S.

    2013-01-01

    Insulators need to be discharged after each wheel revolution. Sensor responses repeatable within one standard deviation in the noise of the signal. Insulators may not need to be cleaned after each revolution. Parent Technology- Mars Environmental Compatibility Assessment/Electrometer Electrostatic sensors with dissimilar cover insulators Protruding insulators tribocharge against regolith simulant Developed for use on the scoop for the 2001 Mars Odyssey lander Wheel Electrostatic Spectrometer Embedded electrostatic sensors in prototype Martian rover wheel If successful, this technology will enable constant electrostatic testing on Mars Air ionizing fan used to neutralize the surface charge on cover insulators . WES rolled on JSClA lunar simulant Control experiment -Static elimination not conducted between trials -Capacitor discharged after each experiment Charge neutralization experiment -Static elimination conducted between trials -Capacitor discharged after each experiment. Air ionizing fan used on insulators after each wheel revolution Capacitor discharged after each trial Care was taken to roll WES with same speed/pressure Error bars represent one standard deviation in the noise of e ach sensor

  5. Our Wheels Project: Finding the Extraordinary within the Ordinary

    Science.gov (United States)

    Cowan, Jane

    2015-01-01

    The Wheels Project took place from January to March, 2012 in a junior kindergarten/kindergarten classroom at the St. Nicholas location of Owl Child Care Services of Ontario in Waterloo. Owl Child Care Services, a nonprofit registered charity, operates seven centers in Kitchener, Waterloo, and Cambridge, Ontario. Owl is one of the largest…

  6. Single wheel testers, single track testers, and instrumented tractors

    Science.gov (United States)

    Single wheel testers and single track testers are used for determining tractive performance characteristics of tires and tracks. Instrumented tractors are useful in determining the tractive performance of tractors. These machines are also used for determining soil-tire and soil-track interactions,...

  7. A new solution method for wheel/rail rolling contact.

    Science.gov (United States)

    Yang, Jian; Song, Hua; Fu, Lihua; Wang, Meng; Li, Wei

    2016-01-01

    To solve the problem of wheel/rail rolling contact of nonlinear steady-state curving, a three-dimensional transient finite element (FE) model is developed by the explicit software ANSYS/LS-DYNA. To improve the solving speed and efficiency, an explicit-explicit order solution method is put forward based on analysis of the features of implicit and explicit algorithm. The solution method was first applied to calculate the pre-loading of wheel/rail rolling contact with explicit algorithm, and then the results became the initial conditions in solving the dynamic process of wheel/rail rolling contact with explicit algorithm as well. Simultaneously, the common implicit-explicit order solution method is used to solve the FE model. Results show that the explicit-explicit order solution method has faster operation speed and higher efficiency than the implicit-explicit order solution method while the solution accuracy is almost the same. Hence, the explicit-explicit order solution method is more suitable for the wheel/rail rolling contact model with large scale and high nonlinearity.

  8. 29 CFR 1926.303 - Abrasive wheels and tools.

    Science.gov (United States)

    2010-07-01

    ... Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.303 Abrasive wheels and tools. (a) Power. All grinding machines shall be supplied with sufficient power to maintain...

  9. Outer Wheel Uniformity of the ElectroMagnetic Endcap Calorimeter

    CERN Document Server

    Oliver, C

    2005-01-01

    An analysis of the test beam data for the uniformity of three ECC modules is presented. A non-uniformity of less than 0.6 per cent is obtained for the outer wheel of the three modules. The results are found to be independent of the signal reconstruction method used as long as the residuals are kept below 4 per cent.

  10. Theoretical design study of the MSFC wind-wheel turbine

    Science.gov (United States)

    Frost, W.; Kessel, P. A.

    1982-01-01

    A wind wheel turbine (WWT) is studied. Evaluation of the probable performance, possible practical applications, and economic viability as compared to other conventional wind energy systems is discussed. The WWT apparatus is essentially a bladed wheel which is directly exposed to the wind on the upper half and exposed to wind through multiple ducting on the lower half. The multiple ducts consist of a forward duct (front concentrator) and two side ducts (side concentrators). The forced rotation of the wheel is then converted to power through appropriate subsystems. Test results on two simple models, a paper model and a stainless steel model, are reported. Measured values of power coefficients over wind speeds ranging from 4 to 16 m/s are given. An analytical model of a four bladed wheel is also developed. Overall design features of the wind turbine are evaluated and discussed. Turbine sizing is specified for a 5 and 25 kW machine. Suggested improvements to the original design to increase performance and performance predictions for an improved WWT design are given.

  11. Dynamics of micromachined vibrating gimbal and wheel gyroscope

    Institute of Scientific and Technical Information of China (English)

    TijingCAI

    2000-01-01

    We deduce dynamic equations of micromachined vibrating gimbal and wheel gyroscope and give an approximate solution of enough accuracy. The comparison between the approximate solution and the solution used often in the literature is given. According to property of the approximate solution a decoupled two-axes gyroscope will be composed of two single-axes gyroscopes.

  12. Wheel-rail interaction at short-wave irregularities

    NARCIS (Netherlands)

    Steenbergen, M.J.M.M.

    2008-01-01

    Short-wave irregularities in the wheel-rail interface are at the basis of track and vehicle damage and deterioration. On the short term, they result into high dynamic train-track interaction forces and a high energy input into the system that must be dissipated in the different system components or

  13. Using the Pottery Wheel to Explore Topics in Calculus

    Science.gov (United States)

    Farnell, Elin; Snipes, Marie A.

    2015-01-01

    Students sometimes struggle with visualizing the three-dimensional solids encountered in certain integral problems in a calculus class. We present a project in which students create solids of revolution with clay on a pottery wheel and estimate the volumes of these objects using Riemann sums. In addition to giving students an opportunity for…

  14. Stochastic Wheel-Slip Compensation Based Robot Localization and Mapping

    Directory of Open Access Journals (Sweden)

    SIDHARTHAN, R. K.

    2016-05-01

    Full Text Available Wheel slip compensation is vital for building accurate and reliable dead reckoning based robot localization and mapping algorithms. This investigation presents stochastic slip compensation scheme for robot localization and mapping. Main idea of the slip compensation technique is to use wheel-slip data obtained from experiments to model the variations in slip velocity as Gaussian distributions. This leads to a family of models that are switched depending on the input command. To obtain the wheel-slip measurements, experiments are conducted on a wheeled mobile robot and the measurements thus obtained are used to build the Gaussian models. Then the localization and mapping algorithm is tested on an experimental terrain and a new metric called the map spread factor is used to evaluate the ability of the slip compensation technique. Our results clearly indicate that the proposed methodology improves the accuracy by 72.55% for rotation and 66.67% for translation motion as against an uncompensated mapping system. The proposed compensation technique eliminates the need for extro receptive sensors for slip compensation, complex feature extraction and association algorithms. As a result, we obtain a simple slip compensation scheme for localization and mapping.

  15. Wheeled mobility (wheelchair) service delivery: scope of the evidence.

    Science.gov (United States)

    Greer, Nancy; Brasure, Michelle; Wilt, Timothy J

    2012-01-17

    Identifying the appropriate wheelchair for a person who needs one has implications for both disabled persons and society. For someone with severe locomotive problems, the right wheelchair can affect mobility and quality of life. However, policymakers are concerned about the increasing demand for unnecessarily elaborate chairs. The Office of Inspector General, U.S. Department of Health and Human Services, issued 4 reports between 2009 and 2011 detailing fraud and misapplication of Medicare funds for powered wheelchairs, more than a decade after similar concerns were first raised by 4 contractors who process claims for durable medical equipment. Subsequent concerns have arisen about whether some impaired persons who need wheeled mobility devices may now be inappropriately denied coverage. A transparent, evidence-based approach to wheeled mobility service delivery (the matching of mobility-impaired persons to appropriate devices and supporting services) might lessen these concerns. This review describes the process of wheeled mobility service delivery for long-term wheelchair users with complex rehabilitation needs and presents findings from a survey of the literature (published and gray) and interviews with key informants. Recommended steps in the delivery process were identified in textbooks, guidelines, and published literature. Delivery processes shared many commonalities; however, no research supports the recommended approaches. A search of bibliographic databases through March 2011 identified 24 studies that evaluated aspects of wheeled mobility service delivery. Most were observational, exploratory studies designed to determine consumer use of and satisfaction with the process. The evidence base for the effectiveness of approaches to wheeled mobility service delivery is insufficient, and additional research is needed to develop standards and guidelines.

  16. The new forging process of a wheel hub drop forging

    Directory of Open Access Journals (Sweden)

    A. Gontarz

    2006-08-01

    Full Text Available Purpose: The main purpose of the research was working out a new flashless forming process of wheel hubforging in three-slide forging press (TSFP. It was assumed that the new process would be more effective thanthe forging processes applied in typical forging machines.Design/methodology/approach: The designing of the new process was based on the simulation by finiteelement method with the assumption of 3D state of strain. Calculations were made mainly for the analysis of thematerial flow kinematics and the process loads parameters. Experimental research were also made determiningthe dependency of clamping load in the function of forming load. On the basis of the analysis, the formingprocess of a wheel hub drop forging on the TSFP was worked out.Findings: The results of research confirmed the possibility of flashless forming process of wheel hub forgingin TSFP with axial cavities. The main parameters limiting the forming processes of wheel hub forgings are:permissible upsetting ratio and reciprocal relation of forming and clamping forces.Research limitations/implications: The further research within the range of determining force parameters fordifferent types of material and schemata of forming in TSFP were considered as purposeful. The works dealingwith analysis of forming processes of different types of products in order to classify drop forgings possible toform in this press will be examined.Practical implications: The comparison of the new forming process with the forging process on hammershowed majority of advantages which include: decrease of time and energy, decrease of drop forging weight andmachining, decrease of material consumption.Originality/value: The new process of wheel hub forging forming with axial cavities was worked out. Theparameters important during designing of forming processes in TSFP were provided. The relations betweenforces of forming tools were also determined.

  17. Cryogenic filter wheel design for an infrared instrument

    Science.gov (United States)

    Azcue, Joaquín.; Villanueva, Carlos; Sánchez, Antonio; Polo, Cristina; Reina, Manuel; Carretero, Angel; Torres, Josefina; Ramos, Gonzalo; Gonzalez, Luis M.; Sabau, Maria D.; Najarro, Francisco; Pintado, Jesús M.

    2014-09-01

    In the last two decades, Spain has built up a strong IR community which has successfully contributed to space instruments, reaching Co-PI level in the SPICA mission (Space Infrared Telescope for Cosmology and Astrophysics). Under the SPICA mission, INTA, focused on the SAFARI instrument requirements but highly adaptable to other missions has designed a cryogenic low dissipation filter wheel with six positions, taking as starting point the past experience of the team with the OSIRIS instrument (ROSETTA mission) filter wheels and adapting the design to work at cryogenic temperatures. One of the main goals of the mechanism is to use as much as possible commercial components and test them at cryogenic temperature. This paper is focused on the design of the filter wheel, including the material selection for each of the main components of the mechanism, the design of elastic mount for the filter assembly, a positioner device designed to provide positional accuracy and repeatability to the filter, allowing the locking of the position without dissipation. In order to know the position of the wheel on every moment a position sensor based on a Hall sensor was developed. A series of cryogenic tests have been performed in order to validate the material configuration selected, the ball bearing lubrication and the selection of the motor. A stepper motor characterization campaign was performed including heat dissipation measurements. The result is a six position filter wheel highly adaptable to different configurations and motors using commercial components. The mechanism was successfully tested at INTA facilities at 20K at breadboard level.

  18. Innovative grinding wheel design for cost-effective machining of advanced ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Licht, R.H.; Kuo, P.; Liu, S.; Murphy, D.; Picone, J.W.; Ramanath, S.

    2000-05-01

    This Final Report covers the Phase II Innovative Grinding Wheel (IGW) program in which Norton Company successfully developed a novel grinding wheel for cost-effective cylindrical grinding of advanced ceramics. In 1995, Norton Company successfully completed the 16-month Phase I technical effort to define requirements, design, develop, and evaluate a next-generation grinding wheel for cost-effective cylindrical grinding of advanced ceramics using small prototype wheels. The Phase II program was initiated to scale-up the new superabrasive wheel specification to larger diameters, 305-mm to 406-mm, required for most production grinding of cylindrical ceramic parts, and to perform in-house and independent validation grinding tests.

  19. DEFINITION OF LOCOMOTIVE TRACTION FORCE WITH REGARD TO UNEVEN LOADING OF WHEEL-MOTOR BLOCK

    Directory of Open Access Journals (Sweden)

    B. Ye. Bodnar

    2013-11-01

    Full Text Available Purpose. The article describes the most common methods for determining the locomotive traction force. Solving the tasks of traction calculations involves determination of the forces influencing the train at every point of the way. When choosing a rational trajectory of the train motion and the development of operational regulations of train driving it is necessary to determine the actual value of the locomotive traction force. Considering various factors, power value of traction electric motor of locomotive may have significant differences. Advancement of the operational definition system of the locomotive traction force during the calculations by electrical parameters of traction electric motor with regard to uneven load of wheel-motor block is the purpose of the article. Methodology. The method of determining the traction force of locomotives and diesel locomotives with electric transmission, which is based on primary data acquisition of traction electric engines of direct current behavior, was proposed. Sensors and their integration into the electrical circuitry of the locomotive in order to get the data in digital form and for operational calculation of the each traction motor mode and the definition of locomotive traction force are presented. Findings. The experimental investigation of the system of locomotive traction force determination with the electric traction motor ED-105 was offered. A comparison of electrical and mechanical power of the electric motor was conducted. Originality. The system of locomotives power operational definition, which takes into account the variable electro-mechanical factors of wheel and motor blocks and increases the accuracy of the calculations, was proposed. Practical value. The system is a part of an onboard complex in definition of energy-efficient regimes for trains movement and provides the definition of accelerating and decelerating forces.

  20. 77 FR 70478 - RG Steel Wheeling, LLC, Wheeling Office, A Division Of RG Steel, LLC, Including On-Site Leased...

    Science.gov (United States)

    2012-11-26

    ..., Including On-Site Leased Workers From Pro Unlimited and Green Energy Initiatives LLC, Including Workers...-site leased workers from Pro Unlimited and Green Energy Initiatives, LLC, Wheeling, West Virginia (TA-W... their wages reported through a separate unemployment insurance (UI) tax account under the name...

  1. A novel instrumented multipeg running wheel system, Step-Wheel, for monitoring and controlling complex sequential stepping in mice.

    Science.gov (United States)

    Kitsukawa, Takashi; Nagata, Masatoshi; Yanagihara, Dai; Tomioka, Ryohei; Utsumi, Hideko; Kubota, Yasuo; Yagi, Takeshi; Graybiel, Ann M; Yamamori, Tetsuo

    2011-07-01

    Motor control is critical in daily life as well as in artistic and athletic performance and thus is the subject of intense interest in neuroscience. Mouse models of movement disorders have proven valuable for many aspects of investigation, but adequate methods for analyzing complex motor control in mouse models have not been fully established. Here, we report the development of a novel running-wheel system that can be used to evoke simple and complex stepping patterns in mice. The stepping patterns are controlled by spatially organized pegs, which serve as footholds that can be arranged in adjustable, ladder-like configurations. The mice run as they drink water from a spout, providing reward, while the wheel turns at a constant speed. The stepping patterns of the mice can thus be controlled not only spatially, but also temporally. A voltage sensor to detect paw touches is attached to each peg, allowing precise registration of footfalls. We show that this device can be used to analyze patterns of complex motor coordination in mice. We further demonstrate that it is possible to measure patterns of neural activity with chronically implanted tetrodes as the mice engage in vigorous running bouts. We suggest that this instrumented multipeg running wheel (which we name the Step-Wheel System) can serve as an important tool in analyzing motor control and motor learning in mice.

  2. Piezoelectric drive circuit

    Science.gov (United States)

    Treu, Jr., Charles A.

    1999-08-31

    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes.

  3. Fundamentals of electrical drives

    CERN Document Server

    Veltman, André; De Doncker, Rik W

    2007-01-01

    Provides a comprehensive introduction to various aspects of electrical drive systems. This volume provides a presentation of dynamic generic models that cover all major electrical machine types and modulation/control components of a drive as well as dynamic and steady state analysis of transformers and electrical machines.

  4. Electric vehicles: Driving range

    Science.gov (United States)

    Kempton, Willett

    2016-09-01

    For uptake of electric vehicles to increase, consumers' driving-range needs must be fulfilled. Analysis of the driving patterns of personal vehicles in the US now shows that today's electric vehicles can meet all travel needs on almost 90% of days from a single overnight charge.

  5. Recognizing driving in haste

    NARCIS (Netherlands)

    Rendón-Vélez, E.

    2014-01-01

    One can often hear people discussing the reasons why a road accident has happened: “She had to pick up her kids in the school before four o’clock and she was driving in haste and careless”, “He was stressed, he wanted to reach the beginning of the football match, tried to drive faster and didn't app

  6. Drive Around the World

    Institute of Scientific and Technical Information of China (English)

    Yang Wei

    2008-01-01

    @@ "It's so cool that I can drive on my own,and my own car,"Cao Gang,WOrking for a private company in Changsha,capital city of Hunan Province,mid-south China,said in excitement when he newly bought Ben Ben,a Chinese local auto brand of Chang'an,with his freshly-passed driving license.

  7. Recognizing driving in haste

    NARCIS (Netherlands)

    Rendón-Vélez, E.

    2014-01-01

    One can often hear people discussing the reasons why a road accident has happened: “She had to pick up her kids in the school before four o’clock and she was driving in haste and careless”, “He was stressed, he wanted to reach the beginning of the football match, tried to drive faster and didn't app

  8. Electric Vehicle - Economical driving

    DEFF Research Database (Denmark)

    Jensen, VCE, Steen V.; Schøn, Henriette

    1999-01-01

    How do you reduce the energy-wast when driving and loading EV's - or rather: How do I get more km/l out of an EV......How do you reduce the energy-wast when driving and loading EV's - or rather: How do I get more km/l out of an EV...

  9. Recognizing driving in haste

    NARCIS (Netherlands)

    Rendón-Vélez, E.

    2014-01-01

    One can often hear people discussing the reasons why a road accident has happened: “She had to pick up her kids in the school before four o’clock and she was driving in haste and careless”, “He was stressed, he wanted to reach the beginning of the football match, tried to drive faster and didn't

  10. 陀螺轮连杆自行车的设计研究%Research and Design of Link Rod Bicycle with Gyro Wheel

    Institute of Scientific and Technical Information of China (English)

    范春燕; 高贵军; 魏学良; 史冬博

    2016-01-01

    In order to remove the bondage of traditional exercise bikes to human body movement, we put forward design ideas of the integration of the riding comfort, control science, leisure, entertainment, fitness, designed a new type of gyro wheel connecting rod bike using innova-tive bike driving mode. The bicycle use four bar linkage mechanism combination frame,to stretch the rope to drive the gyro wheel drives the rear wheel,through acceleration of the cone gyro wheel,make uniform motion in a straight line into the acceleration of the rear wheel traction speed of the circular motion. Gyro wheel connecting rod bike uses the straight line driving force of human body move-ment, to use block and tackle, gyro wheel structure, fast driving rear wheel movement,along with guidance system to change the driving direction,keep the balance of body, achieve rapid, stable, efficient movement. Studies have shown that the gyro wheel connecting rod bike fully embody the people-oriented design concept,make the per-son under the comfortable sitting posture, or try to play function of the body in different position transformation limb,by varying the combination and movement posture of hands and feet,increasing the movement skill,flexibility, promoting sports a lot of fun,implement the body carrying the load, improving the effect of exercise and the body core strength,is conducive to the healthy development and perfect body shaping. The vehicle research and development provides reference sample basis for the gyro wheel drive equipment development, at the same time, drive principle of gyro wheel cant cone shaft also has laid the foundation for sports load control theory support.%为了解除传统健身自行车对人体运动的束缚,提出集骑乘舒适、操控科学、健身、代步、休闲娱乐于一体的设计新理念,采用创新的自行车驱动方式,设计出一款新型的陀螺轮连杆自行车。该自行车运用四杆联动机构组合车架,实现以拉伸

  11. Sleep apnoea and driving risk: the need for regulation

    Directory of Open Access Journals (Sweden)

    Walter T. McNicholas

    2015-12-01

    Full Text Available Obstructive sleep apnoea syndrome (OSAS is a highly prevalent chronic respiratory disorder with prevalence among adult males of ≥10%. The most common daytime symptom associated with OSAS is excessive sleepiness, which in more severe manifestations can result in sleepiness at the wheel while driving and probably contributes to the substantial increase in accident risk among patients with OSAS. Fortunately, current evidence indicates that successful therapy of OSAS, particularly with continuous positive airway pressure, can bring the accident risk down to levels similar to an equivalent general population. The recognition of the increased driving accident risk in OSAS prompted the Transport and Mobility Directorate of the European Commission to establish a working group on this topic in 2012, which ultimately led to a revision of Annex III of the EU Driving Licence Directive, which is subject to mandatory implementation by European Union member states by December 2015. This directive specifies that patients with moderate or severe OSAS associated with significant daytime sleepiness should be prohibited from driving until effective therapy is established. These new regulations are designed to balance the legitimate objective of public safety with not penalising OSAS patients who are complying with effective therapy. Successful implementation of regulations on driving in OSAS patients must also include measures to educate relevant stakeholders including patients, medical personnel, traffic police and employers in the transport industry. The key objective is to encourage patients with possible OSAS to seek diagnosis and treatment and not to inhibit OSAS patients from coming forward.

  12. A method for improved accuracy in three dimensions for determining wheel/rail contact points

    Science.gov (United States)

    Yang, Xinwen; Gu, Shaojie; Zhou, Shunhua; Zhou, Yu; Lian, Songliang

    2015-11-01

    Searching for the contact points between wheels and rails is important because these points represent the points of exerted contact forces. In order to obtain an accurate contact point and an in-depth description of the wheel/rail contact behaviours on a curved track or in a turnout, a method with improved accuracy in three dimensions is proposed to determine the contact points and the contact patches between the wheel and the rail when considering the effect of the yaw angle and the roll angle on the motion of the wheel set. The proposed method, with no need of the curve fitting of the wheel and rail profiles, can accurately, directly, and comprehensively determine the contact interface distances between the wheel and the rail. The range iteration algorithm is used to improve the computation efficiency and reduce the calculation required. The present computation method is applied for the analysis of the contact of rails of CHINA (CHN) 75 kg/m and wheel sets of wearing type tread of China's freight cars. In addition, it can be proved that the results of the proposed method are consistent with that of Kalker's program CONTACT, and the maximum deviation from the wheel/rail contact patch area of this two methods is approximately 5%. The proposed method, can also be used to investigate static wheel/rail contact. Some wheel/rail contact points and contact patch distributions are discussed and assessed, wheel and rail non-worn and worn profiles included.

  13. Analysis of the individual factors affecting mobile phone use while driving in France: socio-demographic characteristics, car and phone use in professional and private contexts.

    Science.gov (United States)

    Brusque, Corinne; Alauzet, Aline

    2008-01-01

    In France, as in many other countries, phoning while driving is legally restricted because of its negative impact on driving performance which increases accident risk. Nevertheless, it is still a frequently observed practice and one which has not been analyzed in detail. This study attempts to identify the profiles of those who use mobile phones while at the wheel and determine the forms taken by this use. A representative sample of 1973 French people was interviewed by phone on their driving practices and mobile phone use in everyday life and their mobile phone use while driving. Logistics regressions have been conducted to highlight the explanatory factors of phoning while driving. Strong differences between males and females have been shown. For the male population, age is the main explanatory factor of phoning while driving, followed by phone use for work-related reasons and extensive mobile phone use in everyday life. For females, high mileage and intensive use of mobile phone are the only two explanatory factors. We defined the intensive phone use at the wheel group as drivers who receive or send at least five or more calls per day while driving. There is no socio-demographic variable related to this practice. Car and phone uses in everyday life are the only explanatory factors for this intensive mobile use of the phone at the wheel.

  14. THE ANALISYS OF RAILWAY MULTI MOTORS ELECTRICAL DRIVE DYNAMIC

    Directory of Open Access Journals (Sweden)

    V. I. Khilmon

    2015-01-01

    Full Text Available The importance of multi motors electrical traction drive dynamic analysis is denoted by its large application in electrical driving railway vehicles. In this paper an analysis is presented for two inducton motors traction drive with frequency inverter, vector control, and speed sensors of each electrical drive. The goal of this work is the analysis of two induction motors electrical drive, taking into account parametric perturbations and also a limited moment of wheel-rail adhesion, by laboratory study and simulation. Because of difference between motor’s parameters, it is necessary for parallel work to select motors with identical resistances and inductive winding. For this purpose the parametric identification method was used for each electrical drive, and also for two parallel motors. The result of identification was used in control setting.The  slippage  of  the  traction  drives  is  difficult  to  reproduce  in  laboratory;  therefore a mathematical modeling and simulation of mechanical part with a traction force restriction, specific for railway transport, were carried out. The suggested simulation is built with account of elastic deformations in kinetic chain, transforming traction force. The model permits to study a dynamic system in various circumstances.The results of laboratory investigations and simulation of dynamic regimes for two motor electrical drives are presented in this article. The results of analysis show, that a minimal difference between any parameters of two motors, parallel connected to convertor, is important for the slippage stability.

  15. NUMERICAL SIMULATION OF TWO-POINT CONTACT BETWEEN WHEEL AND RAIL

    Institute of Scientific and Technical Information of China (English)

    Jun Zhang; Shouguang Sun; Xuesong Jin

    2009-01-01

    The elastic-plastic contact problem with rolling friction of wheel-rail is solved using the FE parametric quadratic programming method. Thus, the complex elastic-plastic contact problem can be calculated with high accuracy and efficiency, while the Hertz's hypothesis and the elastic semi-space assumption are avoided. Based on the 'one-point' contact calculation of wheel-rail, the computational model of 'two-point' contact are established and calculated when the wheel flange is close to the rail. In the case of 'two-point' contact, the changing laws of wheelrail contact are introduced and contact forces in various load cases are carefully analyzed. The main reason of wheel flange wear and rail side wear is found. Lubrication computational model of the wheel flange is constructed. Comparing with the result without lubrication, the contact force between wheel flange and rail decreases, which is beneficial for reducing the wear of wheel-rail.

  16. Indirect method for wheel-rail force measurement and derailment evaluation

    Science.gov (United States)

    Wei, Lai; Zeng, Jing; Wu, Pingbo; Gao, Hao

    2014-12-01

    Wheel set flange derailment criteria for railway vehicles are derived and the influence of wheel-rail contact parameters is studied. An indirect method for wheel-rail force measurement based on these derailment evaluation criteria is proposed. Laboratory tests for the calibration of strain-force devices on the bearing box are carried out to determine the relationship between the applied force and the measured strain. The simulation package, SIMPACK, is used to develop a passenger car model to generate wheel-rail forces and vibration signals. Different cases are considered in this model to provide an accurate validation of the identified wheel-rail forces. A feasibility test is conducted in the Beijing Loop test line using a passenger car equipped with a set of strain gauges on the wheel set. The comparison of the force time history applied to the instrumented wheel set and that obtained using the indirect method is presented.

  17. Method for the multi-criteria optimization of car wheel suspension mechanisms

    Directory of Open Access Journals (Sweden)

    Catalin Alexandru

    2016-08-01

    Full Text Available The paper deals with a general method for the multi-criteria optimization of the rear wheels suspension mechanisms in terms of kinematic behavior. The suspension mechanism is decomposed in basic binary links, and the kinematic synthesis is separately performed for each of them. The design variables are the global coordinates of the joint locations on the car body (chassis. The disposing of the joints on the wheel carrier were exclusively established by constructive criteria. The design objectives relate to kinematic position parameters of the wheel (displacements of the wheel centre along longitudinal and transversal directions, and modifications of the wheel axis direction, the optimization goal being to minimize these variations during the wheel travel. A computer program for the kinematic study was developed in C++. The application was performed for the wheel suspension mechanism of a race car.

  18. Bionic design of configuration of rigid wheel moving on sand and numerical analysis on its traction performance%沙地刚性轮构型仿生设计及牵引性能数值分析

    Institute of Scientific and Technical Information of China (English)

    张锐; 罗刚; 薛书亮; 杨明明; 刘芳; 张四华; 潘润铎; 李建桥

    2015-01-01

    and the lunar soil simulants were simulated. The thrusts of lunar soil simulants were composed of four parts. The first part is the horizontal component forces of the tangential contact forces of the lunar soil simulant particles on the wheel outer boundary rim. The second part is the horizontal component forces of the normal contact forces of the lunar soil simulant particles on the wheel outer boundary rim after the bottom dead center. The third part is the normal contact forces of the lunar soil simulant particles on the lateral wall of the wheel active edge. The fourth part is the microscopic acting forces just like the horizontal positive component forces of the tangential contact forces. The moving wheel is subjected to the strong normal contact forces, caused by the compaction of the loads on the wheel and the cutting between the active side of the wheel rim and the lunar soil simulants. Because of the influences of the contact constitutive model characteristic of the lunar soil simulant particles, the small tangential contact forces of the lunar soil simulant particles are small. At the same time, the simulated results of the rigid wheel with bionic wheel lugs were compared with those of the rigid wheel with rectangular wheel lugs under the same simulation conditions. The simulated results showed that the bionic wheel lug presents three advantages. Firstly, the bionic wheel lug could solidify the loose lunar simulants under the moving wheel through driving the lunar simulant particles toward the bottom left part, which provided the larger adhesive forces for locomotion. In contrast, the rigid wheel with rectangle wheel lugs tended to increase the local voids by driving the lunar soil simulants toward different directions. Secondly, while entering into the lunar soil simulants, the bionic lug reduced the disturbance on the surface layer particles of the lunar soil simulants by the three typical smooth curves of the bionic lug, which caused the small angles

  19. To the question of modeling of wheels and rails wear processes

    Directory of Open Access Journals (Sweden)

    S.V. Myamlin

    2013-06-01

    Full Text Available Purpose. There is a need of wear process modeling in the wheel-rail system. This is related to the fact that the wear processes in this system are absolutely different in the initial and final stages. The profile change of rail and, especially, of the wheels caused by the wear significantly affects the rolling stock dynamics, traffic safety and the resource of the wheels and rails. Wear modeling and the traffic safety evaluation requires the accounting of the low frequency component forces (including the modeling of transitional areas affecting the wheel on the side of the rail and carriage in motion of rolling stock, so the statistical analysis is not possible. Methodology. The method of mathematical modeling of the wheel set and the rail interaction was used during the research conducting. Findings. As a result of the modeling of the wheel set motion on the rail track, the mathematic model with 19 freedom degrees was obtained. This model takes into account the axle torque and studies wheels constructions as the components of the mechanical systems, consisting of a hub and tire. Originality. The mathematic model allows evaluating the wear degree of the wheels and rails when using on the rolling stock not only all-metal wheel sets, but also compound ones with the use of spring wheels and independent rotation of semi-axes with the wheels. Practical value. The development of the improved mathematical model of freight car wheel set motion with differential rotation of the wheels and compound axles allows studying the wear processes of wheels and rails.

  20. Innovative grinding wheel design for cost-effective machining of advanced ceramics. Phase I, final report

    Energy Technology Data Exchange (ETDEWEB)

    Licht, R.H.; Ramanath, S.; Simpson, M.; Lilley, E.

    1996-02-01

    Norton Company successfully completed the 16-month Phase I technical effort to define requirements, design, develop, and evaluate a next-generation grinding wheel for cost-effective cylindrical grinding of advanced ceramics. This program was a cooperative effort involving three Norton groups representing a superabrasive grinding wheel manufacturer, a diamond film manufacturing division and a ceramic research center. The program was divided into two technical tasks, Task 1, Analysis of Required Grinding Wheel Characteristics, and Task 2, Design and Prototype Development. In Task 1 we performed a parallel path approach with Superabrasive metal-bond development and the higher technical risk, CVD diamond wheel development. For the Superabrasive approach, Task 1 included bond wear and strength tests to engineer bond-wear characteristics. This task culminated in a small-wheel screening test plunge grinding sialon disks. In Task 2, an improved Superabrasive metal-bond specification for low-cost machining of ceramics in external cylindrical grinding mode was identified. The experimental wheel successfully ground three types of advanced ceramics without the need for wheel dressing. The spindle power consumed by this wheel during test grinding of NC-520 sialon is as much as to 30% lower compared to a standard resin bonded wheel with 100 diamond concentration. The wheel wear with this improved metal bond was an order of magnitude lower than the resin-bonded wheel, which would significantly reduce ceramic grinding costs through fewer wheel changes for retruing and replacements. Evaluation of ceramic specimens from both Tasks 1 and 2 tests for all three ceramic materials did not show evidence of unusual grinding damage. The novel CVD-diamond-wheel approach was incorporated in this program as part of Task 1. The important factors affecting the grinding performance of diamond wheels made by CVD coating preforms were determined.

  1. Sliding-mode and proportional-derivative-type motion control with radial basis function neural network based estimators for wheeled vehicles

    Science.gov (United States)

    Pamosoaji, Anugrah K.; Thuong Cat, Pham; Hong, Keum-Shik

    2014-12-01

    An obstacle avoidance problem of rear-steered wheeled vehicles in consideration of the presence of uncertainties is addressed. Modelling errors and additional uncertainties are taken into consideration. Controller designs for driving and steering motors are designed. A proportional-derivative-type driving motor controller and a sliding-mode steering controller combined with radial basis function neural network (RBFNN) based estimators are proposed. The convergence properties of the RBFNN-based estimators are proven by the Stone-Weierstrass theorem. The stability of the proposed control law is proven using Lyapunov stability analysis. The obstacle avoidance strategy utilising the sliding surface adjustment to an existing navigation method is presented. It is concluded that the driving velocity and steering-angle performances of the proposed control system are satisfactory.

  2. Vorticity amplification near the stagnation point of landing gear wheels

    Science.gov (United States)

    Feltham, G.; Ekmekci, A.

    2014-04-01

    The vicinity near the forward stagnation point of landing-gear wheels has been found to support a mechanism for oncoming streams of weak vorticity to collect, grow, and amplify into discrete large-scale vortical structures that then shed with a distinct periodicity. To the authors' knowledge, such a flow phenomenon has never been reported before for landing gear wheels, which are in essence finite (three-dimensional) cylinders. To gain further insight into this phenomenon, a detailed experimental study has been undertaken employing the hydrogen bubble visualization and Particle Image Velocimetry techniques. A very thin platinum wire, similar to those used in hydrogen bubble visualization applications, was placed upstream of the wheel model to produce two streams of weak vorticity (with opposite sign) that convected toward the model. As the vorticity streams enter the stagnation region of the wheels, significant flow deceleration and vorticity stretching act to collect, grow, and amplify the incoming vorticity streams into large-scale vortical structures. Experiments were performed at a fixed Reynolds number, with a value of 32 500 when defined based on the diameter of the wheel and a value of 21 based on the diameter of the vorticity-generating upstream wire. First, to establish a baseline, the natural flow field (without the presence of an upstream wire) was characterized, where experimentally determined values for the stagnation boundary-layer thickness and the velocity profile along the stagnation streamline were both found to agree with the values provided in the literature for two-dimensional cylinders. Subsequently, the dynamics of vorticity collection, growth, amplification, and shedding were studied. The size, stand-off distance and the shedding frequency of the vortical structures forming near the stagnation region were all found to strongly depend on the impingement location of the inbound vorticity on the wheel. A simple relationship between the non

  3. Turbulent current drive mechanisms

    Science.gov (United States)

    McDevitt, Christopher J.; Tang, Xian-Zhu; Guo, Zehua

    2017-08-01

    Mechanisms through which plasma microturbulence can drive a mean electron plasma current are derived. The efficiency through which these turbulent contributions can drive deviations from neoclassical predictions of the electron current profile is computed by employing a linearized Coulomb collision operator. It is found that a non-diffusive contribution to the electron momentum flux as well as an anomalous electron-ion momentum exchange term provide the most efficient means through which turbulence can modify the mean electron current for the cases considered. Such turbulent contributions appear as an effective EMF within Ohm's law and hence provide an ideal means for driving deviations from neoclassical predictions.

  4. Polar Direct Drive

    Science.gov (United States)

    Skupsky, S.

    2003-10-01

    Direct drive offers the potential of higher target gain on the National Ignition Facility (NIF) than x-ray drive: The initial direct-drive target design had a 1-D gain of 45 and consisted primarily of a pure cryogenic DT shell. Using the expected levels of target and laser nonuniformities for the NIF, two-dimensional (2-D) hydrodynamic simulations predicted target gains around 30.(P.W. McKenty et al.), Phys. Plasmas 8, 2315 (2001). More-recent designs have shown that higher target gains could be obtained by replacing a portion of the DT shell with ``wetted'' CH foam and by using adiabat shaping: (1) Higher-Z material (C) in the foam increases laser absorption by about 40% (from 60% absorption to 85%).(S. Skupsky et al.), in Inertial Fusion Sciences and Applications 2001, edited by K. Tanaka et al. (Elsevier, Paris, 2002), p. 240. (2) Adiabat shaping allows the main portion of the fuel to be placed on a lower adiabat without compromising target stability.(V.N. Goncharov et al.), Phys. Plasmas 10, 1906 (2003). These direct-drive concepts can be tested on the NIF, long before that facility is converted to a direct-drive (spherically symmetric) irradiation configuration. Using the NIF x-ray-drive beam configuration, some of the near-polar beams could be pointed to better illuminate the target's equator. These more-oblique, equatorial beams will have lower absorption and reduced drive efficiency than the polar beams. One strategy to compensate for the difference in polar and equatorial drive is to reduce the irradiation at the poles and employ different pulse shapes to accommodate the time-dependent variations in drive and absorption. This concept of polar direct drive (PDD) has been studied using the 2-D hydrocode DRACO to determine the requirements for achieving ignition and moderate target gain for the NIF. Experiments on the OMEGA laser will examine the effects of oblique irradiation on target drive. Results of simulations for different direct-drive target designs

  5. Impulsive Driving: Definition and Measurement Using the I-Driving Scale (IDS).

    Science.gov (United States)

    Pérez-Moreno, Elisa; Hernández-Lloreda, María José; Gallego-Largo, Trinidad Ruiz; Castellanos, Miguel Ángel

    2015-11-27

    Impulsivity has been widely studied in the context of traffic. The trait is believed to be the root of some accidents, along with other variables like aggression and anger. The present research objective is to develop a new scale - the I-Driving Scale (IDS) - to evaluate and measure the construct of impulsivity in specific driving situations. To that end, two studies were conducted, with 162 and 107 participants, respectively. In both studies, participants were recruited via their social networks, and answered anonymously. In addition to the IDS, they completed the Use the Vehicle to Express Anger subscale of the Driving Anger Expression Inventory (DAX), the Driving Anger Scale (DAS), and the Barratt Impulsivity Scale (BIS11), and also provided demographic information. The final scale had 11 items falling into two factors: impatience, and aggressiveness/abruptness. The results show a high consistency (αT = .81, αI = .70, and αA = .85 in the first study; αT = .83, αI = .80, and αA = .88 in the second study). Statistical results of Exploratory Factor Analysis in the first sample indicated goodness of fit to a two-factor model (RMSR = .057, GFI = .98). The second study confirmed that factorial structure (χ2/df = 80.50/43 = 1.87, RMSEA = .088, CFI = .94, TLI = .92). Correlations with other measures indicated the Impatience subscale is associated with different expressions of anger behind the wheel, and directly correlated with the loss of driver's license points. Furthermore, the Aggressiveness or Abruptness subscale was associated with more mechanical aspects, and correlated inversely with age.

  6. Rutting Resistance of Asphalt Overlay with Multilayer Wheel Tracking Test

    Institute of Scientific and Technical Information of China (English)

    LIAO Weidong; CHEN Zheng; WU Shaopeng; MO Liantong; LIU Gang

    2006-01-01

    The rutting resistance of multilayer asphalt overlay was researched by using laboratory wheel tracking test. The effects of loading level and test temperature on rutting resistance of asphalt overlay structure were evaluated by means of multilayer specimens .In comparison with multilayer tests, standard specimens of various layers were also conducted to evaluate the rutting resistance. Experimental results indicated that the test temperature and applied load have a significant effect on rutting resistance of asphalt concrete. Higher test temperature and heavier applied load resulted in higher rut depths. In addition, the mutilayer wheel tracking test has been demonstrated to be a more reasonable solution in evaluation on rutting resistance of asphatt pavement structure beasuse it reflects the cumulative permanent deformation in all of asphalt layers.

  7. Mathematical Modeling of the Braking System of Wheeled Mainline Aircraft

    Directory of Open Access Journals (Sweden)

    I. S. Shumilov

    2016-01-01

    Full Text Available The braking system of the landing gear wheels of a mainline aircraft has to meet mandatory requirements laid out in the Aviation Regulations AP-25 (Para 25.735. «Brakes and brake systems". These requirements are essential when creating the landing gear wheel brake control system (WBCS and are used as main initial data in its mathematical modeling. The WBCS is one of the most important systems to ensure the safe completion of the flight. It is a complex of devices, i.e. units (hydraulic, electrical, and mechanical, connected through piping, wiring, mechanical constraints. This complex should allow optimizing the braking process when a large number of parameters change. The most important of them are the following: runway friction coefficient (RFC, lifting force, weight and of the aircraft, etc. The main structural elements involved in braking the aircraft are: aircraft wheels with pneumatics (air tires and brake discs, WBCS, and cooling system of gear wheels when braking.To consider the aircraft deceleration on the landing run is of essence at the stage of design, development, and improvement of brakes and braking systems. Based on analysis of equation of the aircraft motion and energy balance can be determined energy loading and its basic design parameters, braking distances and braking time.As practice and analysis of energy loading show, they (brake + wheel absorb the aircraftpossessed kinetic energy at the start of braking as much as 60-70%, 70-80%, and 80-90%, respectively, under normal increased, and emergency operating conditions. The paper presents a procedure for the rapid calculation of energy loading of the brake wheel.Currently, the mainline aircrafts use mainly electrohydraulic brake systems in which there are the main, backup, and emergency-parking brake systems. All channels are equipped with automatic anti-skid systems. Their presence in the emergency (the third reserve channel significantly improves the reliability and safety of

  8. Continuous Wheel Momentum Dumping Using Magnetic Torquers and Thrusters

    Science.gov (United States)

    Oh, Hwa-Suk; Choi, Wan-Sik; Eun, Jong-Won

    1996-12-01

    Two momentum management schemes using magnetic torquers and thrusters are sug-gested. The stability of the momentum dumping logic is proved at a general attitude equilibrium. Both momentum dumping control laws are implemented with Pulse-Width- Pulse-Frequency Modulated on-off control, and shown working equally well with the original continuous and variable strength control law. Thrusters are assummed to be asymmetrically configured as a contingency case. Each thruster is fired following separated control laws rather than paired thrusting. Null torque thrusting control is added on the thrust control calculated from the momentum control law for the gener-ation of positive thrusting force. Both magnetic and thrusting control laws guarantee the momentum dumping, however, the wheel inner loop control is needed for the "wheel speed" dumping, The control laws are simulated on the KOrea Multi-Purpose SATellite (KOMPSAT) model.

  9. Effect of machinery wheel load on grass yield

    DEFF Research Database (Denmark)

    Green, Ole; Jørgensen, Rasmus Nyholm; Kristensen, Kristian

    2010-01-01

    Effect of machinery wheel load on grass   Ole Green1, Rasmus N. Jørgensen2, Kristian Kristensen3, René Gislum3, Dionysis Bochtis1, & Claus G. Sørensen1   1University of Aarhus, Dept. of Agricultural Engineering 2University of Southern Denmark, Inst. of Chemical Eng., Biotechnology and Environmental...... 3University of Aarhus, Dept. of Genetics and Biotechnology   Corresponding author: Ole Green Address & e-mail: Research Centre Foulum, Blichers Allé 20, 8830 Tjele. Ole.Green@agrsci.dk     Abstract   Different traffic intensities have been shown to have a negative influence on the yield of grass...... and clover. A full scale grass-clover field trial was established to estimate the effect on clover-grass yields as a function of different wheel loads and tire pressures. The trial comprised 16 different traffic intensities with 35 replicates and 1 traffic free treatment with 245 replicates, totalling 17...

  10. Demographic Profile of Older Adults Using Wheeled Mobility Devices

    Directory of Open Access Journals (Sweden)

    Amol M. Karmarkar

    2011-01-01

    Full Text Available The purpose of this study was to determine whether the use of wheeled mobility devices differed with respect to age, gender, residential setting, and health-related factors among older adults. A total of 723 adults ageing 60 and older are representing three cohorts, from nursing homes, the Center for Assistive Technology, and the wheelchair registry from the Human Engineering Research Laboratories. Wheeled mobility devices were classified into three main groups: manual wheelchairs, power wheelchairs, and scooters. Our results found factors including age, gender, diagnosis, and living settings to be associated with differences in use of manual versus powered mobility devices. Differences in use were also noted for subtypes of manual (depot, standard, and customized and powered (scooter, standard, and customized mobility devices, on demographic, living arrangements, and health-related factors. Consideration of demographic, health-related, and environmental factors during the prescription process may help clinicians identify the most appropriate mobility device for the user.

  11. Characterizing the Perfonnance of the Wheel Electrostatic Spectrometer

    Science.gov (United States)

    Johansen, Michael R.; Mackey, P. J.; Holbert, E.; Clements, J. S.; Calle, C. I.

    2013-01-01

    A Wheel Electrostatic Spectrometer has been developed as a surveying tool to be incorporated into a planetary rover design. Electrostatic sensors with various protruding cover insulators are embedded into a prototype rover wheel. When these insulators come into contact with a surface, a charge develops on the cover insulator through tribocharging. A charge spectrum is created by analyzing the accumulated charge on each of the dissimilar cover insulators. We eventually intend to prove charge spectra can be used o determine differences in planetary regolith properties. We tested the effects of residual surface charge on the cover insulators and discovered a need to discharge the sensor cover insulators after each revolution. We proved the repeatability of the measurements for this sensor package and found that the sensor repeatability lies within one standard deviation of the noise in the signal.

  12. Monitoring Grinding Wheel Redress-life Using Support Vector Machines

    Institute of Scientific and Technical Information of China (English)

    Xun Chen; Thitikorn Limchimchol

    2006-01-01

    Condition monitoring is a very important aspect in automated manufacturing processes. Any malfunction of a machining process will deteriorate production quality and efficiency. This paper presents an application of support vector machines in grinding process monitoring. The paper starts with an overview of grinding behaviour. Grinding force is analysed through a Short Time Fourier Transform (STFT) to identify features for condition monitoring. The Support Vector Machine (SVM) methodology is introduced as a powerful tool for the classification of different wheel wear situations.After training with available signal data, the SVM is able to identify the state of a grinding process. The requirement and strategy for using SVM for grinding process monitoring is discussed, while the result of the example illustrates how effective SVMs can be in determining wheel redress-life.

  13. Soil compaction and structural morphology under tractor wheelings

    Science.gov (United States)

    Shanahan, Peter; Quinton, John; Binley, Andrew; Silgram, Martyn

    2010-05-01

    Compaction of cultivated soils is a major problem for agriculture in terms of yield decline and sustainable soil resource management. Tramline wheelings exacerbate runoff and increase erosion from arable land. The UK Department for Environment, Food and Rural Affairs (Defra) LINK Project - a joint venture between agri-business, land managers and research groups - is currently evaluating a number of methods for alleviating compaction in tractor wheelings across a range of soil types in England. Using innovative applications of agri-geophysics (e.g. ground penetrating radar, electrical resistivity, acoustics and x-ray tomography), this current project aims to determine relationships between properties derived from geophysical methods (e.g. soil moisture, porosity), soil compaction and structural morphology. Such relationships are important for a clearer understanding of hydrological and biogeochemical processes in compacted soils, to address land management practices and develop cost-effective mitigation measures. Our poster will present some early results of this study.

  14. Design and Optimization of Composite Gyroscope Momentum Wheel Rings

    Science.gov (United States)

    Bednarcyk, Brett A.; Arnold, Steven M.

    2007-01-01

    Stress analysis and preliminary design/optimization procedures are presented for gyroscope momentum wheel rings composed of metallic, metal matrix composite, and polymer matrix composite materials. The design of these components involves simultaneously minimizing both true part volume and mass, while maximizing angular momentum. The stress analysis results are combined with an anisotropic failure criterion to formulate a new sizing procedure that provides considerable insight into the design of gyroscope momentum wheel ring components. Results compare the performance of two optimized metallic designs, an optimized SiC/Ti composite design, and an optimized graphite/epoxy composite design. The graphite/epoxy design appears to be far superior to the competitors considered unless a much greater premium is placed on volume efficiency compared to mass efficiency.

  15. Utilization of wheel dop based on ergonomic aspects

    Science.gov (United States)

    Widiasih, Wiwin; Murnawan, Hery; Setiawan, Danny

    2017-06-01

    Time is an important thing in life. People need a tool or equipment to measure time which is divided into two types, namely clock and watch. Everyone needs those kinds of tool. It becomes an opportunity for manufacturer to build a business. However, establishing a business by depending on the demand is not enough, it is necessary to take a consideration of making innovation. Innovation is a difficult thing to find out, but it is not impossible to do it. By creating an innovative product, it can be a strategy to win the competitive market. This study aimed to create an innovative product based on the ergonomic aspects, which was by utilizing wheel dop. This methodology consisted of pre-study, planning and product development, and product analysis. This product utilized wheel dop and was made based on the ergonomic aspects.

  16. Dynamics based modeling of wheeled platform for humanoid robot torso

    Directory of Open Access Journals (Sweden)

    Petrović Vladimir M.

    2016-01-01

    Full Text Available From the ancient mythology till the modern times, people were trying to build an artificial mechanical replica of themselves. Inspired by this long tradition of various engineering projects, we will hereby describe a partly humanoid robotic structure. Our robotic configuration is composed out of an anthropomimetic upper body, but instead of legs it uses a wheeled cart for the motion. In our research, this so-called semi-anthropomimetic structure has a four-wheeled cart. This work is aiming to analyze the behaviour of the robot that is exposed to different kind of external disturbances. Disturbances coming from the outside in the form of external forces (impulse and long term simulate the interactions of the robot and its ambience. Necessary simulations were thoroughly executed (in that way analyzing robotic balance and proper size of the cart is evaluated following the ZMP theoretical background. [Projekat Ministarstva nauke Republike Srbije, br. TR-35003 i br. III-44008

  17. Process capability improvement through DMAIC for aluminum alloy wheel machining

    Science.gov (United States)

    Sharma, G. V. S. S.; Rao, P. Srinivasa; Babu, B. Surendra

    2017-07-01

    This paper first enlists the generic problems of alloy wheel machining and subsequently details on the process improvement of the identified critical-to-quality machining characteristic of A356 aluminum alloy wheel machining process. The causal factors are traced using the Ishikawa diagram and prioritization of corrective actions is done through process failure modes and effects analysis. Process monitoring charts are employed for improving the process capability index of the process, at the industrial benchmark of four sigma level, which is equal to the value of 1.33. The procedure adopted for improving the process capability levels is the define-measure-analyze-improve-control (DMAIC) approach. By following the DMAIC approach, the C p, C pk and C pm showed signs of improvement from an initial value of 0.66, -0.24 and 0.27, to a final value of 4.19, 3.24 and 1.41, respectively.

  18. Experimental analysis and regression prediction of desiccant wheel behavior in high temperature heat pump and desiccant wheel air-conditioning system

    DEFF Research Database (Denmark)

    Sheng, Ying; Zhang, Yufeng; Sun, Yuexia

    2014-01-01

    The objectives of this study are to evaluate the performance of desiccant wheel (DW) in the running system and obtain the useful data for practical application. The combined influences of multiple variables on the performance of desiccant wheel are investigated based on evaluating the indexes of ...

  19. In-Flight Position Calibration of the Cassini Articulated Reaction Wheel Assembly

    Science.gov (United States)

    Brown, Todd S.

    2012-01-01

    NASA's long-lived Cassini-Huygens spacecraft is currently in its 14th year of flight and in the midst of its second, and final, extended mission. Cassini is a massive interplanetary spacecraft that is three axis stabilized and can maintain attitude control using either its reaction control system thrusters or using reaction wheel control. Cassini has four identical reaction wheels, of which three are mutually orthogonal and have a fixed orientation. The fourth reaction wheel has an articulation motor that allows this reaction wheel to be aligned with the momentum direction of any of the other three fixed reaction wheels. The articulation motor allows this reaction wheel to be used as a replacement for any of the other three wheels without any performance degradation. However, due to limitations in the design of this backup system, there are few telemetric indications of the orientation of this reaction wheel following an articulation. This investigation serves to outline the procedures that have been developed by the Cassini Attitude and Articulation Control Subsystem to calibrate the position of the articulated reaction wheel assembly in the event that the momentum direction of this reaction wheel must be reoriented.

  20. A mechanical model for deformable and mesh pattern wheel of lunar roving vehicle

    Science.gov (United States)

    Liang, Zhongchao; Wang, Yongfu; Chen, Gang (Sheng); Gao, Haibo

    2015-12-01

    As an indispensable tool for astronauts on lunar surface, the lunar roving vehicle (LRV) is of great significance for manned lunar exploration. An LRV moves on loose and soft lunar soil, so the mechanical property of its wheels directly affects the mobility performance. The wheels used for LRV have deformable and mesh pattern, therefore, the existing mechanical theory of vehicle wheel cannot be used directly for analyzing the property of LRV wheels. In this paper, a new mechanical model for LRV wheel is proposed. At first, a mechanical model for a rigid normal wheel is presented, which involves in multiple conventional parameters such as vertical load, tangential traction force, lateral force, and slip ratio. Secondly, six equivalent coefficients are introduced to amend the rigid normal wheel model to fit for the wheels with deformable and mesh-pattern in LRV application. Thirdly, the values of the six equivalent coefficients are identified by using experimental data obtained in an LRV's single wheel testing. Finally, the identified mechanical model for LRV's wheel with deformable and mesh pattern are further verified and validated by using additional experimental results.

  1. Assessment: A Driving Force.

    Science.gov (United States)

    Rakow, Steven J.

    1992-01-01

    Asserts that educational assessment drives the curriculum. Thus, assessment is very important in contemplating reform in science education. Assessment should be an integral part of the instructional process, utilizing diagnostic testing, monitoring, and summative evaluations. (PR)

  2. Driving in a womb

    NARCIS (Netherlands)

    Anonymous

    Drive thousands of kilometres on just a litre of fuel? During the annual Shell eco-marathon at the end of May, schoolchildren and students – including a team from TU Delft – demonstrated that it can indeed be done.

  3. The new forging process of a wheel hub drop forging

    OpenAIRE

    A. Gontarz

    2006-01-01

    Purpose: The main purpose of the research was working out a new flashless forming process of wheel hubforging in three-slide forging press (TSFP). It was assumed that the new process would be more effective thanthe forging processes applied in typical forging machines.Design/methodology/approach: The designing of the new process was based on the simulation by finiteelement method with the assumption of 3D state of strain. Calculations were made mainly for the analysis of thematerial flow kine...

  4. A Bibliographic Survey of Automobile and Aircraft Wheel Shimmy

    Science.gov (United States)

    1951-12-01

    advantage. Many tire mechanics questions continue to require clarificationand work of this character should lead to the establishment, of superior anti-shimmy...Italian) (1945-1946) American Aviation Annali di Matematica (Italian) (1930-1948) Arts et Metiers Association Technique Maritime et Aeronautiquep...tudinal direction of the airplane. Thus, the pendulum-suspended dual-wheel offers a favorable arrangement which may be superior with respect to weight in

  5. Teens Take the Wheel (A Cup of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    2015-10-22

    One of most noteworthy moments in a teenager’s life is earning a driver’s license. While it provides a newfound freedom, it also presents serious risks. In this podcast, Amy Jewett discusses ways to keep young drivers safe behind the wheel.  Created: 10/22/2015 by MMWR.   Date Released: 10/22/2015.

  6. Kinematic Control of Wheeled Snake-Like Mobile Robot

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    From a bionics viewpoint , this paper proposes a mechanical model of a wheeled snake-like mobile mechanism. On the hypothesis of the existing non-holonomic constraints on the robot kinematics, we set up the relationship among the kinetic control parameters in the snake-like movement using Lie group and Lie algebra of the principle fiber bundle and provide some theoretical control methods to realize the snake-like locomotion.

  7. Models of diagnostic relations in a wheeled tractor

    Directory of Open Access Journals (Sweden)

    Ryszard Michalski

    2014-03-01

    Full Text Available Modern wheeled tractors are equipped with new-generation electric and electronic systemswhich control the operation of actuator systems. Such solutions require an on-board computer foronline monitoring of functional performance, exhaust gas emissions, safety and operating parameters.Mechatronic diagnostic systems identify the machine’s actual operating load in different operatingmodes and under specific circumstances.Knowledge engineering methods have not yet been developed in the process of diagnosing a tractor’sdefects, but they seem to offer almost endless possibilities. A defect is defined as every event whichhas an adverse effect on tractor performance and which should be detected in the diagnostic processwith an indication of the type and place of damage as well as the magnitude and variability of damageover time. Diagnostic knowledge is a symbolic representation of empirical relations based on whichdiagnostic procedures are developed.The identification of diagnostic relations based on different methods and information sources willfoster the growth of reliable declarative knowledge comprising facts and state-symptom diagnosticrelations, as well as procedural knowledge which underlies diagnostic inference.The determination of symptom-damage relations requires a knowledge base of potential defects in theassemblies and subassemblies of a wheeled tractor. A diagnostic knowledge base can be created based on the identified diagnostic relations, including data acquired during damage simulations.The identification of diagnostic relations between specific defects and the corresponding parameterswas one of the key steps in the process of developing a mechatronic diagnostic system in a wheeledtractor. To facilitate the detection of specific defects at a given moment, a single set of diagnosticsymptoms was allocated to every defect in a wheeled tractor. Diagnostic symptoms are identified bysensors when threshold values are exceeded

  8. Three results on cycle-wheel Ramsey numbers

    NARCIS (Netherlands)

    Zhang, Yanbo; Broersma, Haitze J.; Chen, Yaojun

    Given two graphs G1 and G2, the Ramsey number R(G1,G2) is the smallest integer N such that, for any graph G of order N, either G1 is a subgraph of G, or G2 is a subgraph of the complement of G. We consider the case that G1 is a cycle and G2 is a (generalized) wheel. We expand the knowledge on exact

  9. Localization of Wheeled Mobile Robot Based on Extended Kalman Filtering

    Directory of Open Access Journals (Sweden)

    Li Guangxu

    2015-01-01

    Full Text Available A mobile robot localization method which combines relative positioning with absolute orientation is presented. The code salver and gyroscope are used for relative positioning, and the laser radar is used to detect absolute orientation. In this paper, we established environmental map, multi-sensor information fusion model, sensors and robot motion model. The Extended Kalman Filtering (EKF is adopted as multi-sensor data fusion technology to realize the precise localization of wheeled mobile robot.

  10. EXPERIMENTAL EVALUATION OF ARTICULATED WHEELED VEHICLES POSITION STABILITY

    Directory of Open Access Journals (Sweden)

    Ye. Dubinin

    2015-07-01

    Full Text Available With introducing a mobile measurement system with linear acceleration sensors there was experimentally determined the parameter of position stability of the articulated wheeled vehicle on the example of HTA-200 «Slobozhanets». It was determined that the position stability was provided within the entire range of operating speeds and accelerations. The obtained results can be used to enhance the traffic safety of articulated vehicles.

  11. Wear Property of Cast Steel Wheel Material in Rail Truck

    Institute of Scientific and Technical Information of China (English)

    MI Guo-fa; LIU Yan-lei; ZHANG Bin; FU Xiu-qin; ZHANG Hong; SONG Guo-xiang

    2009-01-01

    Wear property of material plays a key role in the service time of workpiece.A major objective in the development of new wheel materials is to improve the wear performance.The wear property of B and B+ grade cast steel materials was reported.The results showed that B+ grade cast steel material exhibited better wear property than the B grade material.Carbon content related to the hardness match was the principal factor affecting the wear properties.

  12. Instant Google Drive starter

    CERN Document Server

    Procopio, Mike

    2013-01-01

    This book is a Starter which teaches you how to use Google Drive practically. This book is perfect for people of all skill levels who want to enjoy the benefits of using Google Drive to safely store their files online and in the cloud. It's also great for anyone looking to learn more about cloud computing in general. Readers are expected to have an Internet connection and basic knowledge of using the internet.

  13. Marine winch drive systems

    Energy Technology Data Exchange (ETDEWEB)

    Clifford, M.; Smith, P.M.

    1983-12-01

    In the design of marine winch drive systems, efficiency, controllability, compactness and component layout flexibility are major considerations. This paper discusses design concepts aimed at achieving the above considerations in the design of variable speed, hydrostatic, marine winch drive systems. These concepts utilize a high pressure, load sensing pump, and a low-speed, high-torque (LSHT), radial-piston, hydraulic motor. These components are then shown applied in several open circuit hydrostatic power transmission systems.

  14. Study of the Correlation between the Performances of Lunar Vehicle Wheels Predicted by the Nepean Wheeled Vehicle Performance Model and Test Data

    Science.gov (United States)

    Wong, J. Y.; Asnani, V. M.

    2008-01-01

    This paper describes the results of a study of the correlation between the performances of wheels for lunar vehicles predicted using the Nepean wheeled vehicle performance model (NWVPM), developed under the auspices of Vehicle Systems Development Corporation, Ottawa, Canada, and the corresponding test data presented in Performance evaluation of wheels for lunar vehicles , Technical Report M-70-2, prepared for George C. Marshall Space Flight Center, National Aeronautics and Space Administration (NASA), USA, by the US Army Engineer Waterways Experiment Station (WES). The NWVPM was originally developed for design and performance evaluation of terrestrial off-road wheeled vehicles. The purpose of this study is to assess the potential of the NWVPM for evaluating wheel candidates for the new generation of extra-terrestrial vehicles. Two versions of a wire-mesh wheel and a hoop-spring wheel, which were considered as candidates for lunar roving vehicles for the NASA Apollo program in the late 1960s, together with a pneumatic wheel were examined in this study. The tractive performances of these wheels and of a 464 test vehicle with the pneumatic wheels on air-dry sand were predicted using the NWVPM and compared with the corresponding test data obtained under Earth s gravity and previously documented in the above-named report. While test data on wheel or vehicle performances obtained under Earth s gravity may not necessarily be representative of those on extra-terrestrial bodies, because of the differences in gravity and in environmental conditions, such as atmospheric pressure, it is still a valid approach to use test data obtained under Earth s gravity to evaluate the predictive capability of the NWVPM and its potential applications to predicting wheel or wheeled rover performances on extra-terrestrial bodies. Results of this study show that, using the ratio (P20/W) of the drawbar pull to normal load at 20 per cent slip as a performance indicator, there is a reasonable

  15. Experimental Research of Harmonic Spectrum of Currents at Traction Drive with PMSM

    Directory of Open Access Journals (Sweden)

    J. Novak

    2011-06-01

    Full Text Available The paper deals with the significant results of the experimental research of current harmonic spectrum of traction drive with permanent magnet synchronous motor. The experiments were done on a special workplace with a real traction drive for wheel vehicles. Current harmonic spectrum was analyzed by a specialized device on the base of central measuring station. The knowledge of current marked subharmonic components of stator winding is the most significant finding of experiments. The frequencies of these components are given by multiples of frequency of mechanical speeds. The subharmonic components also pass to input DC current of drive. This fact is important in particular from the point of view of legislative requirements to electromagnetic compatibility of drive with railway interlocking devices.

  16. Dementia and driving.

    Science.gov (United States)

    O'Neill, D; Neubauer, K; Boyle, M; Gerrard, J; Surmon, D; Wilcock, G K

    1992-04-01

    Many European countries test cars, but not their drivers, as they age. There is evidence to suggest that human factors are more important than vehicular factors as causes of motor crashes. The elderly also are involved in more accidents per distance travelled than middle-aged drivers. As the UK relies on self-certification of health by drivers over the age of 70 years, we examined the driving practices of patients with dementia attending a Memory Clinic. Nearly one-fifth of 329 patients with documented dementia continued to drive after the onset of dementia, and impaired driving ability was noted in two-thirds of these. Their families experienced great difficulty in persuading patients to stop driving, and had to invoke outside help in many cases. Neuropsychological tests did not help to identify those who drove badly while activity of daily living scores were related to driving ability. These findings suggest that many patients with dementia drive in an unsafe fashion after the onset of the illness. The present system of self-certification of health by the elderly for driver-licensing purposes needs to be reassessed.

  17. Commissioning a Rotating Target Wheel Assembly for Heavy Element Studies

    Science.gov (United States)

    Fields, L. D.; Bennett, M. E.; Mayorov, D. A.; Folden, C. M.

    2013-10-01

    The heaviest elements are produced artificially by fusing nuclei of light elements within an accelerator to form heavier nuclei. The most direct method to increase the production rate of nuclei is to increase the beam intensity, necessitating the use of a rotating target to minimize damage to the target by deposited heat. Such a target wheel was constructed for heavy element research at Texas A&M University, Cyclotron Institute, consisting of a wheel with three banana-shaped target cutouts. The target is designed to rotate at 1700 rpm, and a fiber optic cable provides a signal to trigger beam pulsing in order to avoid irradiating the spokes between target segments. Following minor mechanical modifications and construction of a dedicated electrical panel, the rotating target assembly was commissioned for a beam experiment. A 15 MeV/u beam of 20Ne was delivered from the K500 cyclotron and detected by a ruggedized silicon detector. The beam pulsing response time was characterized as a function of the rational frequency of the target wheel. Preliminary analysis suggests that the K500 is capable of pulsing at rates of up to 250 Hz, which is sufficient for planned future experiments. Funded by DOE and NSF-REU Program.

  18. MATHEMATICAL MODEL OF ATTITUDE CONTROL BUCKET‐WHEEL EXCAVATOR

    Directory of Open Access Journals (Sweden)

    Ivana ONDERKOVÁ

    2013-07-01

    Full Text Available This lecture deals with the application problems of convertibility GPS system at paddle excavator K 800. The claims of the modern operating surface mining of the excavators requires a lot of information for monitoring of mining process, capacity mining, selective extraction etc. The utilization of monitoring the excavator setting by GPS system proved to be the only one proper because the receivers are resistant to the vibration, dust, temperature divergence and weather changeable. Only the direct contact with communications satellite is required. It means that they can´t be located in a metal construction space (shadow caused by construction elements, influence of electrical high voltage cables even they can´t be located close to the paddle wheel on the paddle boom (shadow possibility caused by cuttinng edge created during lower gangplanks mining. This is the reason that GPS receivers are set uppermost on the metal construction excavator and the mathematical formulation is required for determination of paddle wheel petting. The relations for calculation of the paddle wheel coordinate were defined mathematically and after that the mathematical model was composed.

  19. The Read Out Controller for the ATLAS New Small Wheel

    CERN Document Server

    AUTHOR|(SzGeCERN)781403; The ATLAS collaboration; Popa, Stefan; Tulbure, Traian Tiberiu; Ivanovici, Mihail; Martoiu, Victor Sorin; Levinson, Lorne; Vermeulen, Jos

    2016-01-01

    In the upgrade process of the ATLAS detector, the innermost stations of the endcaps (Small Wheels, SW) will be replaced. The New Small Wheel (NSW) will have two chamber technologies, one for the Level-1 trigger function (small-strip Thin Gap Chambers, sTGC) and one primarily dedicated to precision tracking (Micromegas detectors, MM). Custom front-end Application Specific Integrated Circuits (ASICs) will be used to read and filter information from both the sTGC and MM detectors. In the context of the New Small Wheel data path, we designed the Read Out Controller (ROC) ASIC for handling, preprocessing and formatting the data generated by the NSW VMM upstream chips. The ROC will concentrate the data streams from 8 VMMs, filter data based on the BCID and transmit the data to FELIX via the L1DDC. ROC is composed of 8 VMM Capture modules, a cross-bar and 4 SubROC modules. The output data is sent via 4 high-speed e-links.

  20. Structure Analysis of a Turbocharger Compressor Wheel Using FEA

    Directory of Open Access Journals (Sweden)

    Shaik Mohammad Rafi

    2014-10-01

    Full Text Available When people talk about race cars or high-performance sports cars, the topic of turbochargers usually comes up. Turbochargers also appear on large diesel engines. A turbo can significantly boost an engine's horsepower without significantly increasing its weight, which is the huge benefit that makes turbos so popular. Turbochargers are a type of forced induction system. They compress the air flowing into the engine. The advantage of compressing the air is that it lets the engine squeeze more air into a cylinder, and more air means that more fuel can be added. Therefore, you get more power from each explosion in each cylinder. Here in this project we are designing the compressor wheel by using Pro-E and doing analysis by using FEA package. The main aim of the project is to increase the performance of the compressor wheel for this we are changing the material and also we are changing the existing design. By comparing the results we will get the best model from this data we suggests the design modifications to the company to improve the performance of the compressor wheel.