WorldWideScience

Sample records for unit strapdown imu

  1. The reliability analysis of a separated, dual fail operational redundant strapdown IMU. [inertial measurement unit

    Science.gov (United States)

    Motyka, P.

    1983-01-01

    A methodology for quantitatively analyzing the reliability of redundant avionics systems, in general, and the dual, separated Redundant Strapdown Inertial Measurement Unit (RSDIMU), in particular, is presented. The RSDIMU is described and a candidate failure detection and isolation system presented. A Markov reliability model is employed. The operational states of the system are defined and the single-step state transition diagrams discussed. Graphical results, showing the impact of major system parameters on the reliability of the RSDIMU system, are presented and discussed.

  2. 3D-Calibration for IMU of the Strapdown Inertial Navigation Systems

    Directory of Open Access Journals (Sweden)

    Avrutov V.V.

    2017-01-01

    Full Text Available A new calibration method for Inertial Measurement Unit (IMU of Strapdown Iner-tial Navigation Systems was presented. IMU has been composed of accelerometers, gyroscopes and a circuit of signal processing. Normally, a rate transfer test and multi-position tests are us-ing for IMU calibration. The new calibration method is based on whole angle rotation or finite rotation. In fact it’s suggested to turn over IMU around three axes simultaneously. In order to solve the equation of calibration, it is necessary to provide an equality of a rank of basic matrix into degree of basic matrix. The results of simulated IMU data presented to demonstrate the performance of the new calibration method.

  3. Detailed Test Plan Redundant Sensor Strapdown IMU Evaluation Program

    Science.gov (United States)

    Hartwell, T.; Miyatake, Y.; Wedekind, D. E.

    1971-01-01

    The test plan for a redundant sensor strapdown inertial measuring unit evaluation program is presented. The subjects discussed are: (1) test philosophy and limitations, (2) test sequence, (3) equipment specifications, (4) general operating procedures, (5) calibration procedures, (6) alignment test phase, and (7) navigation test phase. The data and analysis requirements are analyzed.

  4. General test plan redundant sensor strapdown IMU evaluation program

    Science.gov (United States)

    Hartwell, T.; Irwin, H. A.; Miyatake, Y.; Wedekind, D. E.

    1971-01-01

    The general test plan for a redundant sensor strapdown inertial measuring unit evaluation program is presented. The inertial unit contains six gyros and three orthogonal accelerometers. The software incorporates failure detection and correction logic and a land vehicle navigation program. The principal objective of the test is a demonstration of the practicability, reliability, and performance of the inertial measuring unit with failure detection and correction in operational environments.

  5. A detailed description of the sequential probability ratio test for 2-IMU FDI

    Science.gov (United States)

    Rich, T. M.

    1976-01-01

    The sequential probability ratio test (SPRT) for 2-IMU FDI (inertial measuring unit failure detection/isolation) is described. The SPRT is a statistical technique for detecting and isolating soft IMU failures originally developed for the strapdown inertial reference unit. The flowchart of a subroutine incorporating the 2-IMU SPRT is included.

  6. Space Tug laser gyro IMU

    Science.gov (United States)

    Morrison, R.; Walls, B.

    1975-01-01

    A redundant inertial measuring unit (IMU) incorporating six strapdown laser gyros and six accelerometers, arranged so that sensitive axes are normal to the faces of a dodecahedron, provides enhanced reliability with reduced hardware weight. Software monitoring of sensor outputs senses failure of sensors and the system is designed for triple redundancy, with built-in test equipment. Attention is centered on redundancy and fail-safe features, and on the closed-path ring laser gyro arrangement.

  7. Latest results in strapdown airborne gravimetry using an iMAR RQH unit

    DEFF Research Database (Denmark)

    Becker, D.; Becker, M; Olesen, Arne Vestergaard

    2016-01-01

    This paper summarizes the results of four recent airborne gravity campaigns, carried out between October 2013 and October 2015. For the measurements, a strapdown inertial measurement unit, type iMAR RQH 1003, was used in combination with a geodetic two-frequency GNSS receiver (Javad Delta). A cen...

  8. LP-80 IMU program status

    Science.gov (United States)

    Jackson, Edward N.

    Development history, system design features, performance, and hardware status are reviewed for the fourth-generation LP-80 strapdown inertial measurement unit (IMU) which is currently in full-scale development to meet the design objectives required for missiles, torpedoes, drones, and range instrumentation system applications. The LP-80 is fully self-contained and operates at all attitudes, providing digital processed outputs of angular rate and linear acceleration measured in the body axis frame. For range applications, the LP-80 is designed to provide linear velocities with respect to a space stabilized coordinate frame.

  9. Comprehensive Calibration of Strap-Down Tri-Axis Accelerometer Unit

    Directory of Open Access Journals (Sweden)

    Xi Zhang

    2017-02-01

    Full Text Available This paper proposes a comprehensive calibration method to improve the precision of a strap-down tri-axis accelerometer unit, in which parameters are divided into static and dynamic ones. The contribution of the manuscript is that it solves the problem of inappropriate installation and the size effect error for tri-axis accelerometer unit at high speed by using static and dynamic calibration method, respectively. The experiment results show the measuring accuracy of accelerometers is increased by more than one order of magnitude, and the navigation precision is increased by more than two orders of magnitude.

  10. Latest results in strapdown airborne gravimetry using an iMAR RQH unit

    DEFF Research Database (Denmark)

    Becker, D.; Becker, M; Olesen, Arne Vestergaard

    2016-01-01

    ). A centralized Kalman-Filter in combination with an RTS-smoother is used to estimate three-dimensional gravity disturbances, i.e. also including the deflections of the vertical (vector gravimetry). A thermal correction is applied to the QA2000 accelerometers in order to remove most of the long term drifts......, relaxing the common requirement of an adjustment of the strapdown gravity data. Results were evaluated based on cross-over statistics, indicating standard deviations in the range from 1.0 to 1.4 mGal (without adjustment). This is an excellent result for strapdown gravimetry, clearly reaching the accuracy...... level of the classical instruments and thereby emphasizing the large potential of strapdown gravimetry for future campaigns...

  11. Study on the Dynamics of Laser Gyro Strapdown Inertial Measurement Unit System Based on Transfer Matrix Method for Multibody System

    Directory of Open Access Journals (Sweden)

    Gangli Chen

    2013-01-01

    Full Text Available The dynamic test precision of the strapdown inertial measurement unit (SIMU is the basis of estimating accurate motion of various vehicles such as warships, airplanes, spacecrafts, and missiles. So, it is paid great attention in the above fields to increase the dynamic precision of SIMU by decreasing the vibration of the vehicles acting on the SIMU. In this paper, based on the transfer matrix method for multibody system (MSTMM, the multibody system dynamics model of laser gyro strapdown inertial measurement unit (LGSIMU is developed; the overall transfer equation of the system is deduced automatically. The computational results show that the frequency response function of the LGSIMU got by the proposed method and Newton-Euler method have good agreements. Further, the vibration reduction performance and the attitude error responses under harmonic and random excitations are analyzed. The proposed method provides a powerful technique for studying dynamics of LGSIMU because of using MSTMM and its following features: without the global dynamics equations of the system, high programming, low order of system matrix, and high computational speed.

  12. IMU Fault Detection Based on 2-CUSUM

    Directory of Open Access Journals (Sweden)

    Élcio Jeronimo de Oliveira

    2012-01-01

    IMU strapdown platforms using fiber optic gyros (FOG or micro electro mechanical systems (MEMSs. A way to solve this problem makes use of sensor redundancy and parity vector (PV analysis. However, the actual sensor outputs can include some anomalies, as impulsive noise which can be associated with the sensors itself or data acquisition process, committing the elementary threshold criteria as commonly used. Therefore, to overcome this problem, in this work, it is proposed an algorithm based on median filter (MF for prefiltering and chi-square cumulative sum (2-CUSUM only for fault detection (FD applied to an IMU composed by four FOGs.

  13. Error reduction by combining strapdown inertial measurement units in a baseball stitch

    Science.gov (United States)

    Tracy, Leah

    A poor musical performance is rarely due to an inferior instrument. When a device is under performing, the temptation is to find a better device or a new technology to achieve performance objectives; however, another solution may be improving how existing technology is used through a better understanding of device characteristics, i.e., learning to play the instrument better. This thesis explores improving position and attitude estimates of inertial navigation systems (INS) through an understanding of inertial sensor errors, manipulating inertial measurement units (IMUs) to reduce that error and multisensor fusion of multiple IMUs to reduce error in a GPS denied environment.

  14. Confirmation and analysis on the optimal multiposition alignment of strapdown inertial navigation system%捷联惯导系统最优多位置对准的确定与分析

    Institute of Scientific and Technical Information of China (English)

    刘志琴; 王新龙

    2013-01-01

    To realize precise alignment, the optimal multiposition alignment conditions and methods of strapdown inertial navigation system (SINS) were investigated. Using an equivalent error model of SINS established by Lyapunov transform, the observability of SINS error states was quantificationally analyzed by rotating IMU around the orthogonal axes. Then, by research on the relationship between inertial instrument errors and IMU attitudes, the rotational modes by quantitative analysis of inertial measurement unit(IMU) were presented , and the IMU optimal rotating angular positions on which the optimum estimation of SINS error states were achieved . Finally, the simulation results verify the correctness of theoretical analysis.%为了实现捷联惯导系统(SINS,Strapdown Inertial Navigation System)快速精确对准,研究了SINS进行最优多位置对准的条件及方法.利用李雅普诺夫变换得到的SINS等价误差模型,在对惯性测量单元(IMU,Inertial Measurement Unit)绕正交轴旋转时SINS可观测性进行定量分析的基础上,通过研究惯性器件误差与IMU角位置之间的关系,定量分析了IMU的转动方式,明确了使SINS误差状态达到最优估计时IMU的最佳旋转角位置.最后,通过仿真验证了理论分析的正确性.

  15. ON ALGORITHMS CREATION FOR STRAPDOWN STABILIZED GYROCOMPASS OPERATION BASED ON ELECTRICALLY SUSPENDED GYROSCOPE

    Directory of Open Access Journals (Sweden)

    Gennady I. Emelyantsev

    2014-09-01

    Full Text Available The paper presents operation algorithms of ESG-based strapdown stabilized gyrocompass (SSGC located onboard a mobile vehicle. Initial alignment mode and calibration of drift model coefficients onboard a vehicle is aided by reference attitude (heading, pitch and roll angles and position data. The required reference attitude parameters can be generated by joint processing of data from MEMS IMU with gyros and accelerometers and GPS compass. Depending on the vehicle dynamics and required accuracy of generated heading, the system may use IMU based on the fiber-optic gyros and accelerometers instead of MEMS to construct the place vertical. Specific features of SSGC algorithms in heading generation are considered. Calibration and corrected operation modes of the system are described. The SSGC uses two ESGs with orthogonal angular momentum vectors, where one gyro is the reference (unit vector of its angular momentum is aligned with the celestial axis and the other one is virtual (with zero misalignments with respect to the inertial frame, and zero drift model coefficients. Joint processing of SSGC data and external position aiding is realized by extended Kalman filter with full-state feedback control. Simulation modeling results of the system operation algorithms are presented. Simulation modeling has confirmed the system compass effect and determined the time required for calibration of ESG with solid-rotor. The results have been applied at «Concern CSRI “Elektropribor”», JSC

  16. Orbit IMU alignment: Error analysis

    Science.gov (United States)

    Corson, R. W.

    1980-01-01

    A comprehensive accuracy analysis of orbit inertial measurement unit (IMU) alignments using the shuttle star trackers was completed and the results are presented. Monte Carlo techniques were used in a computer simulation of the IMU alignment hardware and software systems to: (1) determine the expected Space Transportation System 1 Flight (STS-1) manual mode IMU alignment accuracy; (2) investigate the accuracy of alignments in later shuttle flights when the automatic mode of star acquisition may be used; and (3) verify that an analytical model previously used for estimating the alignment error is a valid model. The analysis results do not differ significantly from expectations. The standard deviation in the IMU alignment error for STS-1 alignments was determined to the 68 arc seconds per axis. This corresponds to a 99.7% probability that the magnitude of the total alignment error is less than 258 arc seconds.

  17. Onorbit IMU alignment error budget

    Science.gov (United States)

    Corson, R. W.

    1980-01-01

    The Star Tracker, Crew Optical Alignment Sight (COAS), and Inertial Measurement Unit (IMU) from a complex navigation system with a multitude of error sources were combined. A complete list of the system errors is presented. The errors were combined in a rational way to yield an estimate of the IMU alignment accuracy for STS-1. The expected standard deviation in the IMU alignment error for STS-1 type alignments was determined to be 72 arc seconds per axis for star tracker alignments and 188 arc seconds per axis for COAS alignments. These estimates are based on current knowledge of the star tracker, COAS, IMU, and navigation base error specifications, and were partially verified by preliminary Monte Carlo analysis.

  18. Bayesian Train Localization with Particle Filter, Loosely Coupled GNSS, IMU, and a Track Map

    Directory of Open Access Journals (Sweden)

    Oliver Heirich

    2016-01-01

    Full Text Available Train localization is safety-critical and therefore the approach requires a continuous availability and a track-selective accuracy. A probabilistic approach is followed up in order to cope with multiple sensors, measurement errors, imprecise information, and hidden variables as the topological position within the track network. The nonlinear estimation of the train localization posterior is addressed with a novel Rao-Blackwellized particle filter (RBPF approach. There, embedded Kalman filters estimate certain linear state variables while the particle distribution can cope with the nonlinear cases of parallel tracks and switch scenarios. The train localization algorithm is further based on a track map and measurements from a Global Navigation Satellite System (GNSS receiver and an inertial measurement unit (IMU. The GNSS integration is loosely coupled and the IMU integration is achieved without the common strapdown approach and suitable for low-cost IMUs. The implementation is evaluated with real measurements from a regional train at regular passenger service over 230 km of tracks with 107 split switches and parallel track scenarios of 58.5 km. The approach is analyzed with labeled data by means of ground truth of the traveled switch way. Track selectivity results reach 99.3% over parallel track scenarios and 97.2% of correctly resolved switch ways.

  19. Shuttle orbit IMU alignment. Single-precision computation error

    Science.gov (United States)

    Mcclain, C. R.

    1980-01-01

    The source of computational error in the inertial measurement unit (IMU) onorbit alignment software was investigated. Simulation runs were made on the IBM 360/70 computer with the IMU orbit alignment software coded in hal/s. The results indicate that for small IMU misalignment angles (less than 600 arc seconds), single precision computations in combination with the arc cosine method of eigen rotation angle extraction introduces an additional misalignment error of up to 230 arc seconds per axis. Use of the arc sine method, however, produced negligible misalignment error. As a result of this study, the arc sine method was recommended for use in the IMU onorbit alignment software.

  20. Uticaj mesta ugradnje inercijalnog mernog bloka i akcelerometara na grešku u određivanju pozicije aviona / Size effect of the inertial measurement unit and inside IMU accelerometers on aircraft position error

    Directory of Open Access Journals (Sweden)

    Slobodan Janićijević

    2003-03-01

    Full Text Available U ovom članku analiziran je uticaj mesta ugradnje inercijalnog mernog bloka (IMB u avionu i mesta ugradnje akcelerometara u IMB na tačnost određivanja pozicije pomoću bes-platformskog inercijalnog navigacijskog sistema (BINS. Pokazano je da se ovi uticaji ne mogu uvek zanemariti. Izračunata je ukupna greška u određivanju pozicije aviona ako se IMB ugrađuje van centra rotacije aviona, a akcelerometri van centra IMB. Predložena je optimalna orijentacija akcelerometara u IMB-u, kako bi se minimizirao uticaj ugradnje akcelerometara van centra IMB na tačnost određivanja pozicije aviona. Predložen je i način kompenzacije greške. / This paper analyzes the mounting offset size effect of the inertial measurement unit (IMU in aircraft and accelerometers mounting offset size effect in the IMU on the accuracy of strap down inertial navigation system (SDINS. It is also shown that these effects cannot be always neglected. The total size effect error for the IMU has been the computed. An accelerometers optimum orientation inside the IMU has been proposed to minimize size effects on the accuracy of navigation parameters. A manner to compensate these size effects has been proposed as well.

  1. Star Tracker Performance Estimate with IMU

    Science.gov (United States)

    Aretskin-Hariton, Eliot D.; Swank, Aaron J.

    2015-01-01

    A software tool for estimating cross-boresight error of a star tracker combined with an inertial measurement unit (IMU) was developed to support trade studies for the Integrated Radio and Optical Communication project (iROC) at the National Aeronautics and Space Administration Glenn Research Center. Typical laser communication systems, such as the Lunar Laser Communication Demonstration (LLCD) and the Laser Communication Relay Demonstration (LCRD), use a beacon to locate ground stations. iROC is investigating the use of beaconless precision laser pointing to enable laser communication at Mars orbits and beyond. Precision attitude knowledge is essential to the iROC mission to enable high-speed steering of the optical link. The preliminary concept to achieve this precision attitude knowledge is to use star trackers combined with an IMU. The Star Tracker Accuracy (STAcc) software was developed to rapidly assess the capabilities of star tracker and IMU configurations. STAcc determines the overall cross-boresight error of a star tracker with an IMU given the characteristic parameters: quantum efficiency, aperture, apparent star magnitude, exposure time, field of view, photon spread, detector pixels, spacecraft slew rate, maximum stars used for quaternion estimation, and IMU angular random walk. This paper discusses the supporting theory used to construct STAcc, verification of the program and sample results.

  2. An IMU Evaluation Method Using a Signal Grafting Scheme

    Directory of Open Access Journals (Sweden)

    Xiaoji Niu

    2016-06-01

    Full Text Available As various inertial measurement units (IMUs from different manufacturers appear every year, it is not affordable to evaluate every IMU through tests. Therefore, this paper presents an IMU evaluation method by grafting data from the tested IMU to the reference data from a higher-grade IMU. The signal grafting (SG method has several benefits: (a only one set of field tests with a higher-grade IMU is needed, and can be used to evaluate numerous IMUs. Thus, SG is effective and economic because all data from the tested IMU is collected in the lab; (b it is a general approach to compare navigation performances of various IMUs by using the same reference data; and, finally, (c through SG, one can first evaluate an IMU in the lab, and then decide whether to further test it. Moreover, this paper verified the validity of SG to both medium- and low-grade IMUs, and presents and compared two SG strategies, i.e., the basic-error strategy and the full-error strategy. SG provided results similar to field tests, with a difference of under 5% and 19.4%–26.7% for tested tactical-grade and MEMS IMUs. Meanwhile, it was found that dynamic IMU errors were essential to guarantee the effect of the SG method.

  3. An IMU Evaluation Method Using a Signal Grafting Scheme.

    Science.gov (United States)

    Niu, Xiaoji; Wang, Qiang; Li, You; Zhang, Quan; Jiang, Peng

    2016-06-10

    As various inertial measurement units (IMUs) from different manufacturers appear every year, it is not affordable to evaluate every IMU through tests. Therefore, this paper presents an IMU evaluation method by grafting data from the tested IMU to the reference data from a higher-grade IMU. The signal grafting (SG) method has several benefits: (a) only one set of field tests with a higher-grade IMU is needed, and can be used to evaluate numerous IMUs. Thus, SG is effective and economic because all data from the tested IMU is collected in the lab; (b) it is a general approach to compare navigation performances of various IMUs by using the same reference data; and, finally, (c) through SG, one can first evaluate an IMU in the lab, and then decide whether to further test it. Moreover, this paper verified the validity of SG to both medium- and low-grade IMUs, and presents and compared two SG strategies, i.e., the basic-error strategy and the full-error strategy. SG provided results similar to field tests, with a difference of under 5% and 19.4%-26.7% for tested tactical-grade and MEMS IMUs. Meanwhile, it was found that dynamic IMU errors were essential to guarantee the effect of the SG method.

  4. 一种激光断面仪运动补偿用IMU/GPS/OD系统%IMU/GPS/OD integrated system for motion compensation of laser profiler

    Institute of Scientific and Technical Information of China (English)

    刘百奇; 康泰钟; 李建利

    2012-01-01

    针对车载激光路面断面仪性能受检测车垂直振动及姿态变化影响的问题,设计并实现了一种车载激光断面仪运动补偿用IMU/GPS/OD组合测量系统,采用低成本IMU结合捷联解算算法计算检测车的三维位置、速度和姿态,通过GPS和里程仪结合最优滤波技术抑制低成本IMU在捷联解算过程中形成的累积误差,并提出了一种基于IMU/GPS/OD组合测量系统的检测车垂直振动位移的计算方法.最后进行了室内实验验证,实验结果表明,该IMU/GPS/OD组合测量系统应用于车载激光断面仪是可行的.%Laser profiler is widely used to measure road pavements; its accuracy depends on the compensation of the profiler vertical vibration and attitude change on tires and suspension. An IMU/GPS/OD integrated system for motion compensation of laser profiler is designed and realized in this paper. In this system, a low cost IMU combined with strapdown inertial algorithm is used to measure the position and attitude of the vehicle, which are corrected with GPS and OD through optimal filter; and a special algorithm based on IMU/GPS/OD is proposed to calculate the vertical vibration distance of the vehicle. Room experiment was carried out to verify the proposed method, and experiment results indicate that the proposed IMU/GPS/OD integrated system can satisfy the requirements of laser profiler.

  5. MEMS IMU Error Mitigation Using Rotation Modulation Technique

    Directory of Open Access Journals (Sweden)

    Shuang Du

    2016-11-01

    Full Text Available Micro-electro-mechanical-systems (MEMS inertial measurement unit (IMU outputs are corrupted by significant sensor errors. The navigation errors of a MEMS-based inertial navigation system will therefore accumulate very quickly over time. This requires aiding from other sensors such as Global Navigation Satellite Systems (GNSS. However, it will still remain a significant challenge in the presence of GNSS outages, which are typically in urban canopies. This paper proposed a rotary inertial navigation system (INS to mitigate navigation errors caused by MEMS inertial sensor errors when external aiding information is not available. A rotary INS is an inertial navigator in which the IMU is installed on a rotation platform. Application of proper rotation schemes can effectively cancel and reduce sensor errors. A rotary INS has the potential to significantly increase the time period that INS can bridge GNSS outages and make MEMS IMU possible to maintain longer autonomous navigation performance when there is no external aiding. In this research, several IMU rotation schemes (rotation about X-, Y- and Z-axes are analyzed to mitigate the navigation errors caused by MEMS IMU sensor errors. As the IMU rotation induces additional sensor errors, a calibration process is proposed to remove the induced errors. Tests are further conducted with two MEMS IMUs installed on a tri-axial rotation table to verify the error mitigation by IMU rotations.

  6. MEMS IMU Error Mitigation Using Rotation Modulation Technique

    Science.gov (United States)

    Du, Shuang; Sun, Wei; Gao, Yang

    2016-01-01

    Micro-electro-mechanical-systems (MEMS) inertial measurement unit (IMU) outputs are corrupted by significant sensor errors. The navigation errors of a MEMS-based inertial navigation system will therefore accumulate very quickly over time. This requires aiding from other sensors such as Global Navigation Satellite Systems (GNSS). However, it will still remain a significant challenge in the presence of GNSS outages, which are typically in urban canopies. This paper proposed a rotary inertial navigation system (INS) to mitigate navigation errors caused by MEMS inertial sensor errors when external aiding information is not available. A rotary INS is an inertial navigator in which the IMU is installed on a rotation platform. Application of proper rotation schemes can effectively cancel and reduce sensor errors. A rotary INS has the potential to significantly increase the time period that INS can bridge GNSS outages and make MEMS IMU possible to maintain longer autonomous navigation performance when there is no external aiding. In this research, several IMU rotation schemes (rotation about X-, Y- and Z-axes) are analyzed to mitigate the navigation errors caused by MEMS IMU sensor errors. As the IMU rotation induces additional sensor errors, a calibration process is proposed to remove the induced errors. Tests are further conducted with two MEMS IMUs installed on a tri-axial rotation table to verify the error mitigation by IMU rotations. PMID:27916852

  7. Visual-LiDAR Odometry Aided by Reduced IMU

    Directory of Open Access Journals (Sweden)

    Yashar Balazadegan Sarvrood

    2016-01-01

    Full Text Available This paper proposes a method for combining stereo visual odometry, Light Detection And Ranging (LiDAR odometry and reduced Inertial Measurement Unit (IMU including two horizontal accelerometers and one vertical gyro. The proposed method starts with stereo visual odometry to estimate six Degree of Freedom (DoF ego motion to register the point clouds from previous epoch to the current epoch. Then, Generalized Iterative Closest Point (GICP algorithm refines the motion estimation. Afterwards, forward velocity and Azimuth obtained by visual-LiDAR odometer are integrated with reduced IMU outputs in an Extended Kalman Filter (EKF to provide final navigation solution. In this paper, datasets from KITTI (Karlsruhe Institute of Technology and Toyota technological Institute were used to compare stereo visual odometry, integrated stereo visual odometry and reduced IMU, stereo visual-LiDAR odometry and integrated stereo visual-LiDAR odometry and reduced IMU. Integrated stereo visual-LiDAR odometry and reduced IMU outperforms other methods in urban areas with buildings around. Moreover, this method outperforms simulated Reduced Inertial Sensor System (RISS, which uses simulated wheel odometer and reduced IMU. KITTI datasets do not include wheel odometry data. Integrated RTK (Real Time Kinematic GPS (Global Positioning System and IMU was replaced by wheel odometer to simulate the response of RISS method. Visual Odometry (VO-LiDAR is not only more accurate than wheel odometer, but it also provides azimuth aiding to vertical gyro resulting in a more reliable and accurate system. To develop low-cost systems, it would be a good option to use two cameras plus reduced IMU. The cost of such a system will be reduced than using full tactical MEMS (Micro-Electro-Mechanical Sensor based IMUs because two cameras are cheaper than full tactical MEMS based IMUs. The results indicate that integrated stereo visual-LiDAR odometry and reduced IMU can achieve accuracy at the

  8. IMU: inertial sensing of vertical CoM movement.

    Science.gov (United States)

    Esser, Patrick; Dawes, Helen; Collett, Johnny; Howells, Ken

    2009-07-22

    The purpose of this study was to use a quaternion rotation matrix in combination with an integration approach to transform translatory accelerations of the centre of mass (CoM) from an inertial measurement unit (IMU) during walking, from the object system onto the global frame. Second, this paper utilises double integration to determine the relative change in position of the CoM from the vertical acceleration data. Five participants were tested in which an IMU, consisting of accelerometers, gyroscopes and magnetometers was attached on the lower spine estimated centre of mass. Participants were asked to walk three times through a calibrated volume at their self-selected walking speed. Synchronized data were collected by an IMU and an optical motion capture system (OMCS); both measured at 100 Hz. Accelerations of the IMU were transposed onto the global frame using a quaternion rotation matrix. Translatory acceleration, speed and relative change in position from the IMU were compared with the derived data from the OMCS. Peak acceleration in vertical axis showed no significant difference (p> or =0.05). Difference between peak and trough speed showed significant difference (pIMU and OMCS did not show any significant difference (p> or =0.05). These results indicate that quaternions, in combination with Simpsons rule integration, can be used in transforming translatory acceleration from the object frame to the global frame and therefore obtain relative change in position, thus offering a solution for using accelerometers in accurate global frame kinematic gait analyses.

  9. 基于正逆向与降噪的捷联惯导改进快速对准方法%Improved fast alignment method of strapdown INS using bidirectional processes and denoising

    Institute of Scientific and Technical Information of China (English)

    覃方君; 李安; 许江宁

    2014-01-01

    针对捷联惯性导航系统(INS)的快速对准问题,基于双向过程和惯性传感器的降噪方法,提出了一种改进的对准方法。利用双向过程(前向和逆向)反复处理保存的惯性测量单元(IMU)的数据序列实现快速对准,推导了一种新的前向与逆向对准关系。为了减少角随机游走误差的影响,基于小波变换的降噪方法抑制光纤陀螺(FOGs)和加速度计噪声,给出陀螺罗经回路的改进方法的整个流程,并在自研的光纤陀螺捷联惯导系统上进行测试。实测数据实验结果表明,经正逆向与降噪改进后的快速对准方法具有更快的收敛速度,能在不到3 min内完成对准任务,同时也具有更好的对准精度。%To solve fast alignment problem for strapdown inertial navigation system(INS), an improved alignment method is proposed using bidirectional processes and inertial sensors denoising. It is proved that repeatedly making use of the bidirectional processes(forward and backward ) to process the saved inertial measurement unit(IMU) data sequence could help fast alignment. A new relationship between forward and backward processes for alignment is deviated. In order to reduce the effect of angular random walk error, a wavelet-based demoising method is adopted to suppress the noises of fiber optical gyroscopes(FOGs) and accelerometers. And the whole procedure of the improved method based on gyrocompassing loop is given. The fast alignment method has been tested on a self-made FOG strapdown INS. The experiment results show that the improved method has great advantage in alignment speed, which costs less than 3 min to complete the alignment mission, and also has higher alignment accuracy after offline denoising the inertial sensors.

  10. Strapdown Homing Guidance System Design for Some Ammunition

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The strapdown homing guidance system for some ammunition was mainly studied. A strong tracking Kalman filter was designed for the strapdown homing guidance system using the information measured by the strapdown homing seeker to estimate relative movement variables between the ammunition and target. Then the optimal proportional law, which using the estimated information, guided the ammunition. Simulation results show that the designed strapdown homing guidance system with strong tracking Kalman filter can attack the maneuvering target effectively, and satisfy the performance index for the guided ammunition system.

  11. Orbit IMU alinement interpretation of onboard display data

    Science.gov (United States)

    Corson, R.

    1978-01-01

    The space shuttle inertial measurement unit (IMU) alinement algorith was examined to determine the most important alinement starpair selection criterion. Three crew displayed parameters were considered: (1) the results of the separation angle difference (SAD) check for each starpair; (2) the separation angle of each starpair; and (3) the age of each star measurement. It was determined that the SAD for each pair cannot be used to predict the IMu alinement accuracy. If the age of each star measurement is less than approximately 30 minutes, time is a relatively unimportant factor and the most important alinement pair selection criterion is the starpair separation angle. Therefore, when there are three available alinement starpairs and all measurements were taken within the last 30 minutes, the pair with the separation angle closest to 90 degrees should be selected for IMU alinement.

  12. Investigation of estimating accuracy for aerodynamic characteristics of a scaled supersonic experimental airplane using IMU data based on flight simulation

    OpenAIRE

    1999-01-01

    This paper describes a pre-flight estimation method for aerodynamic characteristics and investigates the accuracy of the estimated aerodynamic characteristics of the scaled supersonic experimental airplane, using IMU (Inertial Measurement Unit) data obtained in a flight simulation. The results demonstrate that the required accuracy is not achieved and that the main sources of error are in the estimation of dynamic pressure, misalignment between the body axis and IMU chassis axis, and IMU disc...

  13. Comparison of Four Different Methods for Agricultural Positioning Using GPS and IMU

    Directory of Open Access Journals (Sweden)

    H Goli

    2014-09-01

    Full Text Available In this research, four different positioning methods were compared in order to evaluate their accuracy, using a remotely controlled robot on a specific route. These methods included: using a single GPS module, combining the data from three GPS modules, using an Inertial Measurement Unit (IMU, and GPS/IMU data fusion. The comparison of these four methods showed that GPS/IMU data fusion along with a Kalman filter was the most precise method, having a root mean square error of 23.4cm. Integrating the data acquired simultaneously from three GPS modules with fixed and equally spaced position and far enough from each other, had a root mean square error of 31.3cm was the second most precise method. . Also analysis of the IMU data showed that due to cumulative errors, it was not a suitable method using a single IMU for positioning.

  14. Shuttle onboard IMU alignment methods

    Science.gov (United States)

    Henderson, D. M.

    1976-01-01

    The current approach to the shuttle IMU alignment is based solely on the Apollo Deterministic Method. This method is simple, fast, reliable and provides an accurate estimate for the present cluster to mean of 1,950 transformation matrix. If four or more star sightings are available, the application of least squares analysis can be utilized. The least squares method offers the next level of sophistication to the IMU alignment solution. The least squares method studied shows that a more accurate estimate for the misalignment angles is computed, and the IMU drift rates are a free by-product of the analysis. Core storage requirements are considerably more; estimated 20 to 30 times the core required for the Apollo Deterministic Method. The least squares method offers an intermediate solution utilizing as much data that is available without a complete statistical analysis as in Kalman filtering.

  15. Field Programmable Gate Array Based Parallel Strapdown Algorithm Design for Strapdown Inertial Navigation Systems

    Directory of Open Access Journals (Sweden)

    Long-Hua Ma

    2011-08-01

    Full Text Available A new generalized optimum strapdown algorithm with coning and sculling compensation is presented, in which the position, velocity and attitude updating operations are carried out based on the single-speed structure in which all computations are executed at a single updating rate that is sufficiently high to accurately account for high frequency angular rate and acceleration rectification effects. Different from existing algorithms, the updating rates of the coning and sculling compensations are unrelated with the number of the gyro incremental angle samples and the number of the accelerometer incremental velocity samples. When the output sampling rate of inertial sensors remains constant, this algorithm allows increasing the updating rate of the coning and sculling compensation, yet with more numbers of gyro incremental angle and accelerometer incremental velocity in order to improve the accuracy of system. Then, in order to implement the new strapdown algorithm in a single FPGA chip, the parallelization of the algorithm is designed and its computational complexity is analyzed. The performance of the proposed parallel strapdown algorithm is tested on the Xilinx ISE 12.3 software platform and the FPGA device XC6VLX550T hardware platform on the basis of some fighter data. It is shown that this parallel strapdown algorithm on the FPGA platform can greatly decrease the execution time of algorithm to meet the real-time and high precision requirements of system on the high dynamic environment, relative to the existing implemented on the DSP platform.

  16. Performance Evaluation Criteria and Analysis of Navigation Systems Using Inertial Measurement Unit Technology

    Science.gov (United States)

    2014-06-26

    level. The strapdown IMU mechanization relies on microelectromechanical systems ( MEMS ) technology for the accelerometer and gyroscope triads. The...every system, the outputs of the single-axis sensors that make up the accelerometer and gyroscope are used in conjunction with the navigation system...triads are stationary with respect to the IMU case; thus, the attitude is dead-reckoned numerically using the gyroscope data to provide the vehicle

  17. Calibration Method for Laser Strapdown Inertial Measurement Unit In All Environment Temperature%激光陀螺捷联惯性组合的全温度标定方法

    Institute of Scientific and Technical Information of China (English)

    徐清雷; 韩冰; 邓正隆

    2004-01-01

    给出了激光陀螺捷联惯性组合(IMU)的误差模型,研究了一种利用双轴带温控箱速率转台的参数标定方法,标定出了IMU在各种环境温度下的模型参数,通过温度补偿有效地减小了IMU的导航误差.试验结果表明:该方法标定精度较高,适用于中等精度IMU的参数标定.

  18. IMU-Based Online Kinematic Calibration of Robot Manipulator

    Directory of Open Access Journals (Sweden)

    Guanglong Du

    2013-01-01

    Full Text Available Robot calibration is a useful diagnostic method for improving the positioning accuracy in robot production and maintenance. An online robot self-calibration method based on inertial measurement unit (IMU is presented in this paper. The method requires that the IMU is rigidly attached to the robot manipulator, which makes it possible to obtain the orientation of the manipulator with the orientation of the IMU in real time. This paper proposed an efficient approach which incorporates Factored Quaternion Algorithm (FQA and Kalman Filter (KF to estimate the orientation of the IMU. Then, an Extended Kalman Filter (EKF is used to estimate kinematic parameter errors. Using this proposed orientation estimation method will result in improved reliability and accuracy in determining the orientation of the manipulator. Compared with the existing vision-based self-calibration methods, the great advantage of this method is that it does not need the complex steps, such as camera calibration, images capture, and corner detection, which make the robot calibration procedure more autonomous in a dynamic manufacturing environment. Experimental studies on a GOOGOL GRB3016 robot show that this method has better accuracy, convenience, and effectiveness than vision-based methods.

  19. IMU-based online kinematic calibration of robot manipulator.

    Science.gov (United States)

    Du, Guanglong; Zhang, Ping

    2013-01-01

    Robot calibration is a useful diagnostic method for improving the positioning accuracy in robot production and maintenance. An online robot self-calibration method based on inertial measurement unit (IMU) is presented in this paper. The method requires that the IMU is rigidly attached to the robot manipulator, which makes it possible to obtain the orientation of the manipulator with the orientation of the IMU in real time. This paper proposed an efficient approach which incorporates Factored Quaternion Algorithm (FQA) and Kalman Filter (KF) to estimate the orientation of the IMU. Then, an Extended Kalman Filter (EKF) is used to estimate kinematic parameter errors. Using this proposed orientation estimation method will result in improved reliability and accuracy in determining the orientation of the manipulator. Compared with the existing vision-based self-calibration methods, the great advantage of this method is that it does not need the complex steps, such as camera calibration, images capture, and corner detection, which make the robot calibration procedure more autonomous in a dynamic manufacturing environment. Experimental studies on a GOOGOL GRB3016 robot show that this method has better accuracy, convenience, and effectiveness than vision-based methods.

  20. GPS/MEMS IMU/Microprocessor Board for Navigation

    Science.gov (United States)

    Gender, Thomas K.; Chow, James; Ott, William E.

    2009-01-01

    A miniaturized instrumentation package comprising a (1) Global Positioning System (GPS) receiver, (2) an inertial measurement unit (IMU) consisting largely of surface-micromachined sensors of the microelectromechanical systems (MEMS) type, and (3) a microprocessor, all residing on a single circuit board, is part of the navigation system of a compact robotic spacecraft intended to be released from a larger spacecraft [e.g., the International Space Station (ISS)] for exterior visual inspection of the larger spacecraft. Variants of the package may also be useful in terrestrial collision-detection and -avoidance applications. The navigation solution obtained by integrating the IMU outputs is fed back to a correlator in the GPS receiver to aid in tracking GPS signals. The raw GPS and IMU data are blended in a Kalman filter to obtain an optimal navigation solution, which can be supplemented by range and velocity data obtained by use of (l) a stereoscopic pair of electronic cameras aboard the robotic spacecraft and/or (2) a laser dynamic range imager aboard the ISS. The novelty of the package lies mostly in those aspects of the design of the MEMS IMU that pertain to controlling mechanical resonances and stabilizing scale factors and biases.

  1. PDR with a foot-mounted IMU and ramp detection.

    Science.gov (United States)

    Jiménez, Antonio R; Seco, Fernando; Zampella, Francisco; Prieto, José C; Guevara, Jorge

    2011-01-01

    The localization of persons in indoor environments is nowadays an open problem. There are partial solutions based on the deployment of a network of sensors (Local Positioning Systems or LPS). Other solutions only require the installation of an inertial sensor on the person's body (Pedestrian Dead-Reckoning or PDR). PDR solutions integrate the signals coming from an Inertial Measurement Unit (IMU), which usually contains 3 accelerometers and 3 gyroscopes. The main problem of PDR is the accumulation of positioning errors due to the drift caused by the noise in the sensors. This paper presents a PDR solution that incorporates a drift correction method based on detecting the access ramps usually found in buildings. The ramp correction method is implemented over a PDR framework that uses an Inertial Navigation algorithm (INS) and an IMU attached to the person's foot. Unlike other approaches that use external sensors to correct the drift error, we only use one IMU on the foot. To detect a ramp, the slope of the terrain on which the user is walking, and the change in height sensed when moving forward, are estimated from the IMU. After detection, the ramp is checked for association with one of the existing in a database. For each associated ramp, a position correction is fed into the Kalman Filter in order to refine the INS-PDR solution. Drift-free localization is achieved with positioning errors below 2 meters for 1,000-meter-long routes in a building with a few ramps.

  2. Miniaturized GPS/MEMS IMU integrated board

    Science.gov (United States)

    Lin, Ching-Fang (Inventor)

    2012-01-01

    This invention documents the efforts on the research and development of a miniaturized GPS/MEMS IMU integrated navigation system. A miniaturized GPS/MEMS IMU integrated navigation system is presented; Laser Dynamic Range Imager (LDRI) based alignment algorithm for space applications is discussed. Two navigation cameras are also included to measure the range and range rate which can be integrated into the GPS/MEMS IMU system to enhance the navigation solution.

  3. 基于IMU/LIDAR的月面软着陆自主导航方法%Autonomous Navigation Based on Inertial Measurement Unit and Light Detection and Ranging for Lunar Soft Landing

    Institute of Scientific and Technical Information of China (English)

    江秀强

    2013-01-01

    针对中国探月二、三期工程及未来星际着陆探测任务中对探测器精确着陆的要求,为避免采用导航相机进行导航时的大量图像处理运算对导航实时性的影响及其对星载计算机性能的苛刻要求,同时克服传统导航精度低的缺点,提出一种基于惯性测量单元(IMU)加激光雷达(LIDAR)的着陆段自主导航方法。该方法利用惯性测量单元测得的探测器的加速度和角速度以及激光雷达测得的探测器相对于月面的距离和速度信息,通过改进扩展Kalman滤波估计出探测器的位置、速度和姿态。该方法的运算量较小,保证了良好的实时性,且仿真分析表明采用该方法对月面地形具有较好的适应能力,可获得较高的导航精度。%To satisfy the requirements of pinpoint soft landing in the stage II and III of China's lunar exploration program (CLEP) and interplanetary landing exploration missions in the future, an autonomous navigation method based on IMU/LIDAR is presented for the landing phase in this paper, in order to avoid both the influence on real-time navigation and the strict requirements of the onboard computer performance from a mass of image processing operation when using navigation camera. The location, velocity and attitude of the explorer is estimated by the proposed modified extended Kalman filter utilizing measurements of angular velocity and acceleration from an inertial measurement unit (IMU) as well as Doppler velocity and range observations from an light detection and ranging (LIDAR) system. This method requires less computing and ensures a better real-time property. The results of simulation show that this method can well adapt to the lunar terrain and achieve higher navigation accuracy.

  4. Gait Dynamics Sensing Using IMU Sensor Array System

    Directory of Open Access Journals (Sweden)

    Slavomir Kardos

    2017-01-01

    Full Text Available The article deals with a progressive approach in gait sensing. It is incorporated by IMU (Inertia Measurement Unit complex sensors whose field of acting is mainly the motion sensing in medicine, automotive and other industry, self-balancing systems, etc. They allow acquiring the position and orientation of an object in 3D space. Using several IMU units the sensing array for gait dynamics was made. Based on human gait analysis the 7-sensor array was designed to build a gait motion dynamics sensing system with the possibility of graphical interpretation of data from the sensing modules in real-time graphical application interface under the LabVIEW platform. The results of analyses can serve as the information for medical diagnostic purposes. The main control part of the system is microcontroller, whose function is to control the data collection and flow, provide the communication and power management.

  5. GPS/Reduced IMU with a Local Terrain Predictor in Land Vehicle Navigation

    Directory of Open Access Journals (Sweden)

    Debo Sun

    2008-01-01

    Full Text Available In order to reduce the cost and volume of land vehicle navigation (LVN systems, a “reduced” inertial measurement unit (IMU consisting of only one vertical gyro and two or three accelerometers is generally used and is often integrated with other sensors. Since there are no horizontal gyros in a reduced IMU, the pitch and roll cannot be calculated or observed directly from the inertial data, and the navigation performance is thus affected by local terrain variations. In this work, a reduced IMU is integrated with global positioning system (GPS data and a novel local terrain predictor (LTP algorithm. The latter is used primarily to help estimate the pitch and roll of the reduced IMU system and thus to improve the navigation performance. In this paper, two reduced IMU configurations and two grades of IMUs are investigated using field data. Test results show that the LTP is valid. Specifically, inclusion of the LTP provides more than an 80% horizontal velocity improvement relative to the case when the LTP is not used in a GPS/reduced IMU configuration.

  6. A comparison of stable platform and strapdown airborne gravity

    DEFF Research Database (Denmark)

    Glennie, C.L.; Schwarz, K.P.; Bruton, A.M.

    2000-01-01

    flown along existing shipborne gravity profiles to allow for an independent source of comparison of the results. The results and analysis of these flight tests are presented. The measurement method and error models for both the-stable platform and strapdown INS gravity systems are presented......To date, operational airborne gravity results have been obtained using either a damped two-axis stable platform gravimeter system such as the LaCoste and Romberg (LCR) S-model marine gravimeter or a strapdown inertial navigation system (INS), showing comparable accuracies. In June 1998 three flight...... test's were undertaken which tested an LCR gravimeter and a strapdown INS gravity system side by side. To the authors' knowledge, this was the first time such a comparison flight was undertaken. The flights occurred in Disko Bay, off the west coast of Greenland. Several of the flight lines were partly...

  7. Indoor dynamic positioning system based on strapdown inertial navigation technology

    Science.gov (United States)

    Xing, YaDong; Wu, Hong

    2011-11-01

    Strapdown inertial navigation technology, which is widely used in aerospace, is a navigation technology in which the gyros sensor and accelerometers sensor are rigidly attached to the body of the object. This article describes an application of strapdown inertial navigation technology in indoor dynamic positioning system. The hardware design of the node include the master controller, data collection, sensors, antenna and related peripheral circuit. Positioning algorithm, data acquisition and transmission are done by software programming based on the hardware circuit. The strapdown inertial navigation composed of the hardware and the software could calculate the position of the object. Simulation software(matlab) is used to confirm the correctness of the positioning algorithm which is implemented by software programming in the system. The system uses the wireless sensor network to expand the range of the positioning. The system of which the information transmission is reliable and the mobility is strongly can satisfy the requirements of the emergency.

  8. Monocular camera and IMU integration for indoor position estimation.

    Science.gov (United States)

    Zhang, Yinlong; Tan, Jindong; Zeng, Ziming; Liang, Wei; Xia, Ye

    2014-01-01

    This paper presents a monocular camera (MC) and inertial measurement unit (IMU) integrated approach for indoor position estimation. Unlike the traditional estimation methods, we fix the monocular camera downward to the floor and collect successive frames where textures are orderly distributed and feature points robustly detected, rather than using forward oriented camera in sampling unknown and disordered scenes with pre-determined frame rate and auto-focus metric scale. Meanwhile, camera adopts the constant metric scale and adaptive frame rate determined by IMU data. Furthermore, the corresponding distinctive image feature point matching approaches are employed for visual localizing, i.e., optical flow for fast motion mode; Canny Edge Detector & Harris Feature Point Detector & Sift Descriptor for slow motion mode. For superfast motion and abrupt rotation where images from camera are blurred and unusable, the Extended Kalman Filter is exploited to estimate IMU outputs and to derive the corresponding trajectory. Experimental results validate that our proposed method is effective and accurate in indoor positioning. Since our system is computationally efficient and in compact size, it's well suited for visually impaired people indoor navigation and wheelchaired people indoor localization.

  9. PDR with a Foot-Mounted IMU and Ramp Detection

    Directory of Open Access Journals (Sweden)

    Jorge Guevara

    2011-09-01

    Full Text Available The localization of persons in indoor environments is nowadays an open problem. There are partial solutions based on the deployment of a network of sensors (Local Positioning Systems or LPS. Other solutions only require the installation of an inertial sensor on the person’s body (Pedestrian Dead-Reckoning or PDR. PDR solutions integrate the signals coming from an Inertial Measurement Unit (IMU, which usually contains 3 accelerometers and 3 gyroscopes. The main problem of PDR is the accumulation of positioning errors due to the drift caused by the noise in the sensors. This paper presents a PDR solution that incorporates a drift correction method based on detecting the access ramps usually found in buildings. The ramp correction method is implemented over a PDR framework that uses an Inertial Navigation algorithm (INS and an IMU attached to the person’s foot. Unlike other approaches that use external sensors to correct the drift error, we only use one IMU on the foot. To detect a ramp, the slope of the terrain on which the user is walking, and the change in height sensed when moving forward, are estimated from the IMU. After detection, the ramp is checked for association with one of the existing in a database. For each associated ramp, a position correction is fed into the Kalman Filter in order to refine the INS-PDR solution. Drift-free localization is achieved with positioning errors below 2 meters for 1,000-meter-long routes in a building with a few ramps.

  10. 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...

  11. Modern Breakthrough Technologies Enable New Applications Based on IMU Systems

    Directory of Open Access Journals (Sweden)

    Nunzio Abbate

    2011-01-01

    Full Text Available This paper describes IMU (Inertial Measurement Unit platforms and their main target applications with a special focus on the 10-degree-of-freedom (10-DOF inertial platform iNEMO and its technical features and performances. The iNEMO module is equipped with a 3-axis MEMS accelerometer, a 3-axis MEMS gyroscope, a 3-axis MEMS magnetometer, a pressure sensor, and a temperature sensor. Furthermore, the Microcontroller Unit (MCU collects measurements by the sensors and computes the orientation through a customized Extended Kalman Filter (EKF for sensor fusion.

  12. Sensitivity Study of Strapdown Inertial Sensors in High Performance Applications

    Science.gov (United States)

    1980-12-01

    system error varied with a change in heading 7K. ( xii 1 SENSITIVITY STUDY OF STRAPDOWN INERTIAL SENSORS IN HIGH PERFORMANCE APPLICATIONS I. Introduction...given in Tabla 10. 23 State Meaning o Basic Altitude Damped INS x(1) Error in East Longitude 5.7735 x 1O Ŗ arc min x(2) Error in North Latitude

  13. A comparison of stable platform and strapdown airborne gravity

    DEFF Research Database (Denmark)

    Glennie, C.L.; Schwarz, K.P.; Bruton, A.M.

    2000-01-01

    To date, operational airborne gravity results have been obtained using either a damped two-axis stable platform gravimeter system such as the LaCoste and Romberg (LCR) S-model marine gravimeter or a strapdown inertial navigation system (INS), showing comparable accuracies. In June 1998 three flig...

  14. Purwarupa Kontrol Kestabilan Posisi dan Sikap pada Pesawat Tanpa Awak Menggunakan IMU dan Algoritma Fusion Sensor Kalman Filter

    OpenAIRE

    Ardiantara, Praja Sapta; Sumiharto, Raden; Wibowo, Setyawan Bekti

    2014-01-01

    Flight Control System merupakan salah satu bagian yang penting dalam sebuah UAV yang dapat digunakan untuk menentukan posisi keadaan pesawat agar tetap stabil dan sesuai dengan misi terbang yang dilakukan. Untuk melakukan kontrol kestabilan dari UAV diperlukan salah satu sensor yaitu sensor IMU(Inertial Measurement Unit) dimana dalam pengembangannya terdapat beberapa algoritma yang digunakan dalam pengolahan data yang dikeluarkan dari sensor IMU tersebut. Salah satunya dalam penelitian ini ad...

  15. Marine gravimetry using the strapdown gravimeter SGA-WZ

    Science.gov (United States)

    Cai, Shaokun; Tie, Junbo; Zhang, Kaidong; Cao, Juliang; Wu, Meiping

    2017-06-01

    Gravity can be measured in many ways, from static-point observations to dynamic measurement using land vehicles, ships, aircrafts and satellites. China has developed a gravimetry system based on SINS (Strapdown Inertial Navigation System) named SGA-WZ. This system is the first strapdown gravimetry system in China. Some airborne gravimetry campaigns have been implemented using SGA-WZ. The flight tests indicate that the accuracy of SGA-WZ is 1.5 mGal at a 4.8 km resolution. To test the performance of SGA-WZ when installed on a ship, a marine gravimetry campaign was conducted in the South China Sea in August 2013. In the test, a state-of-the-art commercial sea gravimeter, the LaCoste & Romberg (L&R), was mounted side by side with SGA-WZ. The test contained 30 survey lines in the west-east direction and four groups of repeat lines in four directions; the evaluation of the repeatability was based on repeat lines. The measurement and in-movement alignment algorithm for strapdown gravimeters in the sea are discussed, and the results and analysis of this test are presented. The results from the repeated lines and the comparison with L&R showed that the accuracy of SGA-WZ is at the level of 1 mGal with a resolution between 0.4 and 0.8 km for shipborne gravimetry. These results indicate that the strapdown gravimetry system SGA-WZ can be used in marine gravimetry and the moving base alignment method can improve the computation efficiency greatly when using the strapdown gravimetry system.

  16. Data synchronization in IMU/GPS integrated measurement system of vehicle motion parameters%汽车运动参数IMU/GPS组合测试中的数据同步技术

    Institute of Scientific and Technical Information of China (English)

    刘广孚; 张为公; 李旭; 郭亮

    2006-01-01

    为解决IMU和GPS的数据同步问题,对汽车运动参数IMU/GPS组合测试中的数据同步技术进行了研究.根据GPS和IMU信号的特点,在IMU不提供同步脉冲信号并且不改变它们各自结构的前提下,设计并研制了基于CPLD的同步电路.进行了测量汽车运动参数的试验,行驶路径包括直线和弧线,利用同步电路实现了IMU/GPS数据的同步.试验结果表明:该电路能够准确测量同步时差,有效地解决了IMU和GPS数据的时间同步问题;基于该同步电路的IMU/GPS组合测试系统实现了对多种汽车运动参数的高频测量与解算.%To realize the data synchronization between the inertial measurement unit (IMU) and the global positioning system (GPS), the synchronization technology in the IMU/GPS integrated measurement system of vehicle motion parameters is studied. According to the characteristics of the output signals of the IMU and the GPS, without the IMU synchronization signal, the synchronization circuit based on CPLD is designed and developed, which need not alter the configurations of the IMU and GPS. Experiments of measuring vehicle motion parameters, which rely on the synchronization circuit to realize IMU/GPS data synchronization, are made. The driving routes in experiments comprise a curve and a straight line. Experimental results show that the designed circuit can accurately measure the synchronization time difference and the IMU period, and can effectively solve the data synchronization in IMU/GPS integration. Furthermore, the IMU/GPS integrated measurement system based on the synchronization circuit can measure and calculate many vehicle motion parameters in high frequency mode.

  17. Intent of Study on the Use of a Dual Airborne Laser Scanner (ALS) in Conjunction with a Tactical Grade Inertial Measurement Unit (IMU) for Unmanned Aerial Vehicle (UAV) Navigation and Mapping in Unknown, Non-Global Positioning System (GPS), Environments

    Science.gov (United States)

    2006-08-05

    Zofia Starzyk a. REPORT UNCLASSIFIED b. ABSTRACT UNCLASSIFIED c. THIS PAGE UNCLASSIFIED UL 19 19b. TELEPHONE NUMBER (include area code ...Navigation ( SITAN ) [2][3]. 5 Ohio University Avionics Engineering Center In the 1990s, the complementary nature of GPS to an IMU was quickly realized...ft AGL 14 Ohio University Avionics Engineering Center IV. DUAL ALS SIMULATION Software for the Dual ALS algorithm was written in MATLAB ™ and

  18. Development of a body joint angle measurement system using IMU sensors.

    Science.gov (United States)

    Bakhshi, Saba; Mahoor, Mohammad H; Davidson, Bradley S

    2011-01-01

    This paper presents an approach for measuring and monitoring human body joint angles using inertial measurement unit (IMU) sensors. This type of monitoring is beneficial for therapists and physicians because it facilitates remote assessment of patient activities. In our approach, two IMUs are mounted on the upper leg and the lower leg to measure the Euler angles of each segment. The Euler angles are sent via Bluetooth protocols to a pc for calculating the knee joint angle. In our experiments, we utilized a motion capture system to accurately measure the knee joint angle and used this as the ground truth to assess the accuracy of the IMU system. The range of average error of the system across a variety of motion trials was 0.08 to 3.06 degrees. In summary, the accuracy of the IMU measurement system currently outperforms existing wearable systems such as conductive fiber optic sensors and flex-sensors.

  19. Robust Foot Clearance Estimation Based on the Integration of Foot-Mounted IMU Acceleration Data.

    Science.gov (United States)

    Benoussaad, Mourad; Sijobert, Benoît; Mombaur, Katja; Coste, Christine Azevedo

    2015-12-23

    This paper introduces a method for the robust estimation of foot clearance during walking, using a single inertial measurement unit (IMU) placed on the subject's foot. The proposed solution is based on double integration and drift cancellation of foot acceleration signals. The method is insensitive to misalignment of IMU axes with respect to foot axes. Details are provided regarding calibration and signal processing procedures. Experimental validation was performed on 10 healthy subjects under three walking conditions: normal, fast and with obstacles. Foot clearance estimation results were compared to measurements from an optical motion capture system. The mean error between them is significantly less than 15 % under the various walking conditions.

  20. Calibration of an IMU-Camera Cluster Using Planar Mirror Reflection and Its Observability Analysis

    OpenAIRE

    Panahandeh, Ghazaleh; Jansson, Magnus; Händel, Peter

    2015-01-01

    This paper describes a novel and a low-cost calibration approach to estimate the relative transformation between an inertial measurement unit (IMU) and a camera, which are rigidly mounted together. The calibration is performed by fusing the measurements from the IMU-camera rig moving in front of a planar mirror. To construct the visual observations, we select a set of key features (KFs) attached to the visual inertial rig where the 3-D positions of the KFs are unknown. During calibration, the...

  1. Damping strapdown inertial navigation system based on a Kalman filter

    Science.gov (United States)

    Zhao, Lin; Li, Jiushun; Cheng, Jianhua; Hao, Yong

    2016-11-01

    A damping strapdown inertial navigation system (DSINS) can effectively suppress oscillation errors of strapdown inertial navigation systems (SINSs) and improve the navigation accuracy of SINSs. Aiming at overcoming the disadvantages of traditional damping methods, a DSINS, based on a Kalman filter (KF), is proposed in this paper. Using the measurement data of accelerometers and calculated navigation parameters during the navigation process, the expression of the observation equation is derived. The calculation process of the observation in both the internal damping state and the external damping state is presented. Finally, system oscillation errors are compensated by a KF. Simulation and test results show that, compared with traditional damping methods, the proposed method can reduce system overshoot errors and shorten the convergence time of oscillation errors effectively.

  2. LiDAR-IMU Time Delay Calibration Based on Iterative Closest Point and Iterated Sigma Point Kalman Filter.

    Science.gov (United States)

    Liu, Wanli

    2017-03-08

    The time delay calibration between Light Detection and Ranging (LiDAR) and Inertial Measurement Units (IMUs) is an essential prerequisite for its applications. However, the correspondences between LiDAR and IMU measurements are usually unknown, and thus cannot be computed directly for the time delay calibration. In order to solve the problem of LiDAR-IMU time delay calibration, this paper presents a fusion method based on iterative closest point (ICP) and iterated sigma point Kalman filter (ISPKF), which combines the advantages of ICP and ISPKF. The ICP algorithm can precisely determine the unknown transformation between LiDAR-IMU; and the ISPKF algorithm can optimally estimate the time delay calibration parameters. First of all, the coordinate transformation from the LiDAR frame to the IMU frame is realized. Second, the measurement model and time delay error model of LiDAR and IMU are established. Third, the methodology of the ICP and ISPKF procedure is presented for LiDAR-IMU time delay calibration. Experimental results are presented that validate the proposed method and demonstrate the time delay error can be accurately calibrated.

  3. IMU/GPS System Provides Position and Attitude Data

    Science.gov (United States)

    Lin, Ching Fang

    2006-01-01

    A special navigation system is being developed to provide high-quality information on the position and attitude of a moving platform (an aircraft or spacecraft), for use in pointing and stabilization of a hyperspectral remote-sensing system carried aboard the platform. The system also serves to enable synchronization and interpretation of readouts of all onboard sensors. The heart of the system is a commercially available unit, small enough to be held in one hand, that contains an integral combination of an inertial measurement unit (IMU) of the microelectromechanical systems (MEMS) type, Global Positioning System (GPS) receivers, a differential GPS subsystem, and ancillary data-processing subsystems. The system utilizes GPS carrier-phase measurements to generate time data plus highly accurate and continuous data on the position, attitude, rotation, and acceleration of the platform. Relative to prior navigation systems based on IMU and GPS subsystems, this system is smaller, is less expensive, and performs better. Optionally, the system can easily be connected to a laptop computer for demonstration and evaluation. In addition to airborne and spaceborne remote-sensing applications, there are numerous potential terrestrial sensing, measurement, and navigation applications in diverse endeavors that include forestry, environmental monitoring, agriculture, mining, and robotics.

  4. Performance Analysis of Alignment Process of MEMS IMU

    Directory of Open Access Journals (Sweden)

    Vadim Bistrov

    2012-01-01

    Full Text Available The procedure of determining the initial values of the attitude angles (pitch, roll, and heading is known as the alignment. Also, it is essential to align an inertial system before the start of navigation. Unless the inertial system is not aligned with the vehicle, the information provided by MEMS (microelectromechanical system sensors is not useful for navigating the vehicle. At the moment MEMS gyroscopes have poor characteristics and it’s necessary to develop specific algorithms in order to obtain the attitude information of the object. Most of the standard algorithms for the attitude estimation are not suitable when using MEMS inertial sensors. The wavelet technique, the Kalman filter, and the quaternion are not new in navigation data processing. But the joint use of those techniques for MEMS sensor data processing can give some new results. In this paper the performance of a developed algorithm for the attitude estimation using MEMS IMU (inertial measurement unit is tested. The obtained results are compared with the attitude output of another commercial GPS/IMU device by Xsens. The impact of MEMS sensor measurement noises on an alignment process is analysed. Some recommendations for the Kalman filter algorithm tuning to decrease standard deviation of the attitude estimation are given.

  5. Investigation of GPS/IMU Positioning System for Mining Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Ken L. Stratton

    2006-09-13

    The objective of this project is to investigate the applicability of a combined Global Positioning System and Inertial Measurement Unit (GPS/IMU) for information based displays on earthmoving machines and for automated earthmoving machines in the future. This technology has the potential of allowing an information-based product like Caterpillar's Computer Aided Earthmoving System (CAES) to operate in areas with satellite shading. Satellite shading is an issue in open pit mining because machines are routinely required to operate close to high walls, which reduces significantly the amount of the visible sky to the GPS antenna mounted on the machine. An inertial measurement unit is a product, which provides data for the calculation of position based on sensing accelerations and rotation rates of the machine's rigid body. When this information is coupled with GPS it results in a positioning system that can maintain positioning capability during time periods of shading.

  6. Potential of IMU Sensors in Performance Analysis of Professional Alpine Skiers.

    Science.gov (United States)

    Yu, Gwangjae; Jang, Young Jae; Kim, Jinhyeok; Kim, Jin Hae; Kim, Hye Young; Kim, Kitae; Panday, Siddhartha Bikram

    2016-04-01

    In this paper, we present an analysis to identify a sensor location for an inertial measurement unit (IMU) on the body of a skier and propose the best location to capture turn motions for training. We also validate the manner in which the data from the IMU sensor on the proposed location can characterize ski turns and performance with a series of statistical analyses, including a comparison with data collected from foot pressure sensors. The goal of the study is to logically identify the ideal location on the skier's body to attach the IMU sensor and the best use of the data collected for the skier. The statistical analyses and the hierarchical clustering method indicate that the pelvis is the best location for attachment of an IMU, and numerical validation shows that the data collected from this location can effectively estimate the performance and characteristics of the skier. Moreover, placement of the sensor at this location does not distract the skier's motion, and the sensor can be easily attached and detached. The findings of this study can be used for the development of a wearable device for the routine training of professional skiers.

  7. Potential of IMU Sensors in Performance Analysis of Professional Alpine Skiers

    Science.gov (United States)

    Yu, Gwangjae; Jang, Young Jae; Kim, Jinhyeok; Kim, Jin Hae; Kim, Hye Young; Kim, Kitae; Panday, Siddhartha Bikram

    2016-01-01

    In this paper, we present an analysis to identify a sensor location for an inertial measurement unit (IMU) on the body of a skier and propose the best location to capture turn motions for training. We also validate the manner in which the data from the IMU sensor on the proposed location can characterize ski turns and performance with a series of statistical analyses, including a comparison with data collected from foot pressure sensors. The goal of the study is to logically identify the ideal location on the skier’s body to attach the IMU sensor and the best use of the data collected for the skier. The statistical analyses and the hierarchical clustering method indicate that the pelvis is the best location for attachment of an IMU, and numerical validation shows that the data collected from this location can effectively estimate the performance and characteristics of the skier. Moreover, placement of the sensor at this location does not distract the skier’s motion, and the sensor can be easily attached and detached. The findings of this study can be used for the development of a wearable device for the routine training of professional skiers. PMID:27043579

  8. Real-Time Large Scale 3d Reconstruction by Fusing Kinect and Imu Data

    Science.gov (United States)

    Huai, J.; Zhang, Y.; Yilmaz, A.

    2015-08-01

    Kinect-style RGB-D cameras have been used to build large scale dense 3D maps for indoor environments. These maps can serve many purposes such as robot navigation, and augmented reality. However, to generate dense 3D maps of large scale environments is still very challenging. In this paper, we present a mapping system for 3D reconstruction that fuses measurements from a Kinect and an inertial measurement unit (IMU) to estimate motion. Our major achievements include: (i) Large scale consistent 3D reconstruction is realized by volume shifting and loop closure; (ii) The coarse-to-fine iterative closest point (ICP) algorithm, the SIFT odometry, and IMU odometry are combined to robustly and precisely estimate pose. In particular, ICP runs routinely to track the Kinect motion. If ICP fails in planar areas, the SIFT odometry provides incremental motion estimate. If both ICP and the SIFT odometry fail, e.g., upon abrupt motion or inadequate features, the incremental motion is estimated by the IMU. Additionally, the IMU also observes the roll and pitch angles which can reduce long-term drift of the sensor assembly. In experiments on a consumer laptop, our system estimates motion at 8Hz on average while integrating color images to the local map and saving volumes of meshes concurrently. Moreover, it is immune to tracking failures, and has smaller drift than the state-of-the-art systems in large scale reconstruction.

  9. Error analysis and characterization of new MEMS IMU sensors and integration with PPP

    Institute of Scientific and Technical Information of China (English)

    GAO Yang; DU Shuang

    2013-01-01

    Several new MEMS Inertial Measurement Unit (IMU) sensor products have been released recently with improved performance, which have the potential to support much higher precision applications. New MEMS IMUs include the NavChip from InterSense, the Nav440 from Crossbow, the Landmark30/40 from GTI, the SDI500 from Systron Donner. Since they are new in the market, currently there is limited information about their error characterization which however is important for the construction of proper error models for their integration with other sensors such as GPS. This paper will investigate the error characterization of two new MEMS IMU sensors, namely the NavChip and Nav440, using Allan variance technique. In addition to identifying different error terms, different stochastic error modeling methods, such as Gauss-Markov (GM) and Autoregressive (AR) processes, will also be investigated to assess the MEMS IMU sensor biases. Investigation to integrate new MEMS IMU sensors with Precise Point Positioning (PPP) will also be conducted to address the re-convergence issues.

  10. IMU/DGPS supported photogrammetry in China

    Institute of Scientific and Technical Information of China (English)

    李英成

    2004-01-01

    People's Republic of China is one of the most rapidly developing countries in the world today. There is a great demand on highly actual and accurate spatial information of the whole country, especially of West China which becomes the focus of development of the Chinese government right now and in the next years, but where still not enough topographic maps are available. This raises great challenges to the surveying and mapping community in China. Facing the new challenges the Chinese Academy of Surveying and Mapping ( CASM ) started its pioneer work early 2002 to explore new techniques and technologies available today toward increasing the map productivity. With import of a CCNS/AEROcontrol system in November 2002, the first DGPS/IMU-based photogrammetric project in China was successfully accomplished jointly by CASM, the Germany-based companies IGI and Techedge. Two photogrammetric blocks of 1:4, 000 and 1: 20,000 photo scales, respectively, were flown in Anyang, China. Direct georeferencing and integrated sensor orientation were conducted. Results achieved were proven by using ground checkpoints and compared with those of aerial triangulation. Orthophotos generated based on direct georeferencing shows the high efficiency and quality, and thus proved the promise of the new technology. Furthermore several DGPS/IMU-based photogammetric projects was accomplished one by one and a big project of more than 100, 000 km2 in the Inner Mongolia will be started in August 2003. The paper presents experiences with DGPS/IMU-based photogrammetry in China. Results achieved in concrete projects are shown and evaluated.Politic and technical specialties in China are discussed. Conclusions outline the potential of DGPS/IMU-based photogrammetric production in China.

  11. Video-based realtime IMU-camera calibration for robot navigation

    Science.gov (United States)

    Petersen, Arne; Koch, Reinhard

    2012-06-01

    This paper introduces a new method for fast calibration of inertial measurement units (IMU) with cameras being rigidly coupled. That is, the relative rotation and translation between the IMU and the camera is estimated, allowing for the transfer of IMU data to the cameras coordinate frame. Moreover, the IMUs nuisance parameters (biases and scales) and the horizontal alignment of the initial camera frame are determined. Since an iterated Kalman Filter is used for estimation, information on the estimations precision is also available. Such calibrations are crucial for IMU-aided visual robot navigation, i.e. SLAM, since wrong calibrations cause biases and drifts in the estimated position and orientation. As the estimation is performed in realtime, the calibration can be done using a freehand movement and the estimated parameters can be validated just in time. This provides the opportunity of optimizing the used trajectory online, increasing the quality and minimizing the time effort for calibration. Except for a marker pattern, used for visual tracking, no additional hardware is required. As will be shown, the system is capable of estimating the calibration within a short period of time. Depending on the requested precision trajectories of 30 seconds to a few minutes are sufficient. This allows for calibrating the system at startup. By this, deviations in the calibration due to transport and storage can be compensated. The estimation quality and consistency are evaluated in dependency of the traveled trajectories and the amount of IMU-camera displacement and rotation misalignment. It is analyzed, how different types of visual markers, i.e. 2- and 3-dimensional patterns, effect the estimation. Moreover, the method is applied to mono and stereo vision systems, providing information on the applicability to robot systems. The algorithm is implemented using a modular software framework, such that it can be adopted to altered conditions easily.

  12. Magnetometer-Augmented IMU Simulator: In-Depth Elaboration

    Directory of Open Access Journals (Sweden)

    Thomas Brunner

    2015-03-01

    Full Text Available The location of objects is a growing research topic due, for instance, to the expansion of civil drones or intelligent vehicles. This expansion was made possible through the development of microelectromechanical systems (MEMS, inexpensive and miniaturized inertial sensors. In this context, this article describes the development of a new simulator which generates sensor measurements, giving a specific input trajectory. This will allow the comparison of pose estimation algorithms. To develop this simulator, the measurement equations of every type of sensor have to be analytically determined. To achieve this objective, classical kinematic equations are used for the more common sensors, i.e., accelerometers and rate gyroscopes. As nowadays, the MEMS inertial measurement units (IMUs are generally magnetometer-augmented, an absolute world magnetic model is implemented. After the determination of the perfect measurement (through the error-free sensor models, realistic error models are developed to simulate real IMU behavior. Finally, the developed simulator is subjected to different validation tests.

  13. Magnetometer-augmented IMU simulator: in-depth elaboration.

    Science.gov (United States)

    Brunner, Thomas; Lauffenburger, Jean-Philippe; Changey, Sébastien; Basset, Michel

    2015-03-04

    The location of objects is a growing research topic due, for instance, to the expansion of civil drones or intelligent vehicles. This expansion was made possible through the development of microelectromechanical systems (MEMS), inexpensive and miniaturized inertial sensors. In this context, this article describes the development of a new simulator which generates sensor measurements, giving a specific input trajectory. This will allow the comparison of pose estimation algorithms. To develop this simulator, the measurement equations of every type of sensor have to be analytically determined. To achieve this objective, classical kinematic equations are used for the more common sensors, i.e., accelerometers and rate gyroscopes. As nowadays, the MEMS inertial measurement units (IMUs) are generally magnetometer-augmented, an absolute world magnetic model is implemented. After the determination of the perfect measurement (through the error-free sensor models), realistic error models are developed to simulate real IMU behavior. Finally, the developed simulator is subjected to different validation tests.

  14. Noise modeling and analysis of an IMU-based attitude sensor: improvement of performance by filtering and sensor fusion

    Science.gov (United States)

    K., Nirmal; A. G., Sreejith; Mathew, Joice; Sarpotdar, Mayuresh; Suresh, Ambily; Prakash, Ajin; Safonova, Margarita; Murthy, Jayant

    2016-07-01

    We describe the characterization and removal of noises present in the Inertial Measurement Unit (IMU) MPU- 6050, which was initially used in an attitude sensor, and later used in the development of a pointing system for small balloon-borne astronomical payloads. We found that the performance of the IMU degraded with time because of the accumulation of different errors. Using Allan variance analysis method, we identified the different components of noise present in the IMU, and verified the results by the power spectral density analysis (PSD). We tried to remove the high-frequency noise using smooth filters such as moving average filter and then Savitzky Golay (SG) filter. Even though we managed to filter some high-frequency noise, these filters performance wasn't satisfactory for our application. We found the distribution of the random noise present in IMU using probability density analysis and identified that the noise in our IMU was white Gaussian in nature. Hence, we used a Kalman filter to remove the noise and which gave us good performance real time.

  15. Noise modeling and analysis of an IMU-based attitude sensor: improvement of performance by filtering and sensor fusion

    CERN Document Server

    Nirmal, K; Mathew, Joice; Sarpotdar, Mayuresh; Suresh, Ambily; Prakash, Ajin; Safonova, Margarita; Murthy, Jayant

    2016-01-01

    We describe the characterization and removal of noise present in the Inertial Measurement Unit (IMU) MPU-6050. This IMU was initially used in an attitude sensor (AS) developed in-house, and subsequently implemented in a pointing and stabilization platform developed for small balloon-borne astronomical payloads. We found that the performance of the IMU degrades with time due to the accumulation of different errors. Using the Allan variance analysis method, we identified the different components of noise present in the IMU and verified the results using a power spectral density analysis (PSD). We tried to remove the high-frequency noise using smoothing filters, such as moving average filter and Savitzky-Golay filter. Although we did manage to filter some of the high-frequency noise, the performance of these filters was not satisfactory for our application. We found the distribution of the random noise present in the IMU using a probability density analysis, and identified the noise to be white Gaussian in natur...

  16. Low-cost inertial measurement unit.

    Energy Technology Data Exchange (ETDEWEB)

    Deyle, Travis Jay

    2005-03-01

    Sandia National Laboratories performs many expensive tests using inertial measurement units (IMUs)--systems that use accelerometers, gyroscopes, and other sensors to measure flight dynamics in three dimensions. For the purpose of this report, the metrics used to evaluate an IMU are cost, size, performance, resolution, upgradeability and testing. The cost of a precision IMU is very high and can cost hundreds of thousands of dollars. Thus the goals and results of this project are as follows: (1) Examine the data flow in an IMU and determine a generic IMU design. (2) Discuss a high cost IMU implementation and its theoretically achievable results. (3) Discuss design modifications that would save money for suited applications. (4) Design and implement a low cost IMU and discuss its theoretically achievable results. (5) Test the low cost IMU and compare theoretical results with empirical results. (6) Construct a more streamlined printed circuit board design reducing noise, increasing capabilities, and constructing a self-contained unit. Using these results, we can compare a high cost IMU versus a low cost IMU using the metrics from above. Further, we can examine and suggest situations where a low cost IMU could be used instead of a high cost IMU for saving cost, size, or both.

  17. IMU Take Out储藏柜

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    关于IMU Design推出的Take Out储藏柜,我想用不着解释太多。因为从它的外观你应该可以看出它的特别之处。每一个储藏空间全部独立设计为一个个塑料手提箱,不但方便你将家中杂七杂八的东西分门别类进行管理,还让你在携带时加倍方便。

  18. Estimating IMU heading error from SAR images.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2009-03-01

    Angular orientation errors of the real antenna for Synthetic Aperture Radar (SAR) will manifest as undesired illumination gradients in SAR images. These gradients can be measured, and the pointing error can be calculated. This can be done for single images, but done more robustly using multi-image methods. Several methods are provided in this report. The pointing error can then be fed back to the navigation Kalman filter to correct for problematic heading (yaw) error drift. This can mitigate the need for uncomfortable and undesired IMU alignment maneuvers such as S-turns.

  19. Robust Foot Clearance Estimation Based on the Integration of Foot-Mounted IMU Acceleration Data

    Directory of Open Access Journals (Sweden)

    Mourad Benoussaad

    2015-12-01

    Full Text Available This paper introduces a method for the robust estimation of foot clearance during walking, using a single inertial measurement unit (IMU placed on the subject’s foot. The proposed solution is based on double integration and drift cancellation of foot acceleration signals. The method is insensitive to misalignment of IMU axes with respect to foot axes. Details are provided regarding calibration and signal processing procedures. Experimental validation was performed on 10 healthy subjects under three walking conditions: normal, fast and with obstacles. Foot clearance estimation results were compared to measurements from an optical motion capture system. The mean error between them is significantly less than 15 % under the various walking conditions.

  20. Image Smearing Modeling and Verification for Strapdown Star Sensor

    Institute of Scientific and Technical Information of China (English)

    WANG Haiyong; ZHOU Wenrui; CHENG Xuan; LIN Haoyu

    2012-01-01

    To further extend study on celestial attitude determination with strapdown star sensor from static into dynamic field,one prerequisite is to generate precise dynamic simulating star maps.First a neat analytical solution of the smearing trajectory caused by spacecraft attitude maneuver is deduced successfully,whose parameters cover the geometric size of optics,three-axis angular velocities and CCD integral time.Then for the first time the mathematical law and method are discovered about how to synthesize the two formulae of smearing trajectory and the static Gaussian distribution function (GDF) model,the key of which is a line integral with regard to the static GDF attenuated by a factor 1/Ls (Ls is the arc length of the smearing trajectory) along the smearing trajectory.The dynamic smearing model is then obtained,also in an analytical form.After that,three sets of typical simulating maps and data are simulated from this dynamic model manifesting the expected smearing effects,also compatible with the linear model as its special case of no boresight rotation.Finally,model validity tests on a rate turntable are carried out,which results in a mean correlation coefficient 0.920 0 between the camera images and the corresponding model simulated ones with the same parameters.The sufficient similarity verifies the validity of the dynamic smearing model.This model,after parameter calibration,can serve as a front-end loop of the ground semi-physical simulation system for celestial attitude determination with strapdown star sensor.

  1. a Man-Portable Imu-Free Mobile Mapping System

    Science.gov (United States)

    Nüchter, A.; Borrmann, D.; Koch, P.; Kühn, M.; May, S.

    2015-08-01

    Mobile mapping systems are commonly mounted on cars, ships and robots. The data is directly geo-referenced using GPS data and expensive IMU (inertial measurement systems). Driven by the need for flexible, indoor mapping systems we present an inexpensive mobile mapping solution that can be mounted on a backpack. It combines a horizontally mounted 2D profiler with a constantly spinning 3D laser scanner. The initial system featuring a low-cost MEMS IMU was revealed and demonstrated at MoLaS: Technology Workshop Mobile Laser Scanning at Fraunhofer IPM in Freiburg in November 2014. In this paper, we present an IMU-free solution.

  2. The IMU Calibration Mathematical Modeling and Error Analysis%IMU标定数学建模及误差分析

    Institute of Scientific and Technical Information of China (English)

    赵桂玲; 姜雨含; 李松

    2016-01-01

    The calibration path design and data processing method for inertial measurement unit(IMU)depend on IMU calibration mathematical model. Installation error is an important factor in determining the IMU calibration model. According to the different installation forms of accelerometers and gyroscopes relative to the carrier ,an IMU calibration mathematical modeling method was proposed by coordinate transformation. The affects of IMU calibra⁃tion model error on angular rate and acceleration were derived. It analyzed the influence of IMU calibration model error on inertial navigation system navigation(SINS),and also designed calibration path and data processing meth⁃ods based on the position information provided by turntable. The simulation and turntable experiment results show that IMU calibration model error causes attitude error,velocity error and position error. Also,the expression form of installation error decides the navigation errors caused by IMU calibration model.%惯性测量单元(IMU)标定路径设计和数据处理方法取决于IMU标定数学模型,安装误差是决定IMU标定模型的重要因素。针对工程中加速度计和陀螺相对载体安装方式的不同,提出一种通过坐标系转换矩阵建立IMU标定数学模型的方法,推导IMU标定模型误差与载体角速度和加速度之间的关系,分析IMU标定模型误差对捷联惯性导航系统导航参数的影响,并利用转台提供的位置信息设计IMU标定路径和数据处理方法。仿真和转台实验结果表明:IMU标定数学模型误差引起捷联惯性导航系统速度误差、位置误差和姿态误差;安装误差的表现形式决定了IMU标定模型误差对系统导航精度的影响。

  3. Ultra-tight GPS/IMU Integration based Long-Range Rocket Projectile Navigation

    Directory of Open Access Journals (Sweden)

    Handong Zhao

    2016-01-01

    Full Text Available Accurate navigation is important for long-range rocket projectile’s precise striking. For getting a stable and high-performance navigation result, a ultra-tight global position system (GPS, inertial measuring unit integration (IMU-based navigation approach is proposed. In this study, high-accuracy position information output from IMU in a short time to assist the carrier phase tracking in the GPS receiver, and then fused the output information of IMU and GPS based on federated filter. Meanwhile, introduced the cubature kalman filter as the local filter to replace the unscented kalman filter, and improved it with strong tracking principle, then, improved the federated filter with vector sharing theory. Lastly simulation was carried out based on the real ballistic data, from the estimation error statistic figure. The navigation accuracy of the proposed method is higher than traditional method.Defence Science Journal, Vol. 66, No. 1, January 2016, pp. 64-70, DOI: http://dx.doi.org/10.14429/dsj.66.8326

  4. Inertial measurement unit-camera calibration based on incomplete inertial sensor information

    Institute of Scientific and Technical Information of China (English)

    Hong LIU; Yu-long ZHOU; Zhao-peng GU

    2014-01-01

    This paper is concerned with the problem of estimating the relative orientation between an inertial measurement unit (IMU) and a camera. Unlike most existing IMU-camera calibrations, the main challenge in this paper is that the information output from the IMU is incomplete. For example, only two tilt information can be read from the gravity sensor of a smart phone. Despite incomplete inertial information, there are strong restrictions between the IMU and camera coordinate systems. This paper addresses the incomplete information based IMU-camera calibration problem by exploiting the intrinsic restrictions among the coordinate transformations. First, the IMU transformation between two poses is formulated with the unknown IMU information. Then the defective IMU information is restored using the complementary visual information. Finally, the Levenberg-Marquardt (LM) algorithm is applied to estimate the optimal calibration result in noisy environments. Experiments on both synthetic and real data show the validity and robustness of our algorithm.

  5. Performance analysis of IMU-augmented GNSS tracking systems for space launch vehicles

    Science.gov (United States)

    Braun, Benjamin; Markgraf, Markus; Montenbruck, Oliver

    2016-06-01

    European space launch operators consider the potential of GNSS (global navigation satellite system) as a promising novel means of localization for the purpose of range safety of launch vehicles like Ariane and Vega, since it is expected that recurring costs are lower and accuracy is higher than currently existing systems like radar tracking. Range safety requires continuous information about the position and velocity of the launch vehicle to quickly detect the occurrence of catastrophic events. However, GNSS outages due, for example, to high jerks at fairing and stage jettisons or other external interferences like (un-)intentional jamming cannot be precluded. The OCAM-G experiment on Ariane 5 flight VA219 has provided evidence that GNSS is capable of providing a highly accurate position and velocity solution during most of the flight, but that outages of several seconds do occur. To increase the continuity of a GNSS-based localization system, it is proposed that the GNSS receiver is augmented by an inertial measurement unit (IMU), which is able to output a position and velocity solution even during GNSS outages. Since these outages are expected to be short, a tactical- or even consumer-grade IMU is expected to be sufficient. In this paper, the minimum IMU performance that is required to bridge outages of up to 10 s, and thereby meeting the accuracy requirements of range safety, is determined by means of a thorough simulation study. The focus of the analysis is on current generation microelectromechanical system (MEMS)-based IMU, which is lightweight, low-cost, available commercially and has reached acceptable maturity in the last decade.

  6. Positioning Errors Predicting Method of Strapdown Inertial Navigation Systems Based on PSO-SVM

    Directory of Open Access Journals (Sweden)

    Xunyuan Yin

    2013-01-01

    Full Text Available The strapdown inertial navigation systems (SINS have been widely used for many vehicles, such as commercial airplanes, Unmanned Aerial Vehicles (UAVs, and other types of aircrafts. In order to evaluate the navigation errors precisely and efficiently, a prediction method based on support vector machine (SVM is proposed for positioning error assessment. Firstly, SINS error models that are used for error calculation are established considering several error resources with respect to inertial units. Secondly, flight paths for simulation are designed. Thirdly, the -SVR based prediction method is proposed to predict the positioning errors of navigation systems, and particle swarm optimization (PSO is used for the SVM parameters optimization. Finally, 600 sets of error parameters of SINS are utilized to train the SVM model, which is used for the performance prediction of new navigation systems. By comparing the predicting results with the real errors, the latitudinal predicting accuracy is 92.73%, while the longitudinal predicting accuracy is 91.64%, and PSO is effective to increase the prediction accuracy compared with traditional SVM with fixed parameters. This method is also demonstrated to be effective for error prediction for an entire flight process. Moreover, the prediction method can save 75% of calculation time compared with analyses based on error models.

  7. An Adaptive Damping Network Designed for Strapdown Fiber Optic Gyrocompass System for Ships

    Directory of Open Access Journals (Sweden)

    Jin Sun

    2017-03-01

    Full Text Available The strapdown fiber optic gyrocompass (strapdown FOGC system for ships primarily works on external horizontal damping and undamping statuses. When there are large sea condition changes, the system will switch frequently between the external horizontal damping status and the undamping status. This means that the system is always in an adjustment status and influences the dynamic accuracy of the system. Aiming at the limitations of the conventional damping method, a new design idea is proposed, where the adaptive control method is used to design the horizontal damping network of the strapdown FOGC system. According to the size of acceleration, the parameters of the damping network are changed to make the system error caused by the ship’s maneuvering to a minimum. Furthermore, the jump in damping coefficient was transformed into gradual change to make a smooth system status switch. The adaptive damping network was applied for strapdown FOGC under the static and dynamic condition, and its performance was compared with the conventional damping, and undamping means. Experimental results showed that the adaptive damping network was effective in improving the dynamic performance of the strapdown FOGC.

  8. Aided strapdown inertial navigation for autonomous underwater vehicles

    Science.gov (United States)

    Liu, Yu; Li, X. Rong

    2010-04-01

    This paper presents a navigation algorithm based on aided strapdown inertial navigation (INS) for an underwater autonomous underwater vehicle (AUV). The AUV is equipped with a long baseline (LBL) acoustic positioning system, acoustic Doppler current profiler (ADCP) and a depth sensor to aid the INS. They have, however, much slower data rates than that of the INS. A linearized, quaternion-based dynamic model and measurement model of the INS output errors are presented. Data from different sensors are fused by applying the extended Kalman filer (EKF) to estimate and correct the errors. Due to the difficulty of generating realistic simulation scenario, real data (raw INS measurement) collected from AUV field experiments are processed to test the algorithm. Without knowing the ground truth, however, performance evaluation becomes much more complicated and needs further research. In this paper, the problem is circumvented by considering the post-processed real data as the "ground truth" and noisy raw measurements are generated from this "ground truth" to feed the algorithm. The simulation results demonstrate the algorithm applicability and show that by incorporating readings from the ADCP and the depth sensor, the (horizontal) position errors still increase but with a significant lower rate than the case of stand-alone operation. If the LBL sensor is further included, the navigation errors can be constrained within a certain bound.

  9. IMU-Based Joint Angle Measurement for Gait Analysis

    Directory of Open Access Journals (Sweden)

    Thomas Seel

    2014-04-01

    Full Text Available This contribution is concerned with joint angle calculation based on inertial measurement data in the context of human motion analysis. Unlike most robotic devices, the human body lacks even surfaces and right angles. Therefore, we focus on methods that avoid assuming certain orientations in which the sensors are mounted with respect to the body segments. After a review of available methods that may cope with this challenge, we present a set of new methods for: (1 joint axis and position identification; and (2 flexion/extension joint angle measurement. In particular, we propose methods that use only gyroscopes and accelerometers and, therefore, do not rely on a homogeneous magnetic field. We provide results from gait trials of a transfemoral amputee in which we compare the inertial measurement unit (IMU-based methods to an optical 3D motion capture system. Unlike most authors, we place the optical markers on anatomical landmarks instead of attaching them to the IMUs. Root mean square errors of the knee flexion/extension angles are found to be less than 1° on the prosthesis and about 3° on the human leg. For the plantar/dorsiflexion of the ankle, both deviations are about 1°.

  10. Estimating Thruster Impulses From IMU and Doppler Data

    Science.gov (United States)

    Lisano, Michael E.; Kruizinga, Gerhard L.

    2009-01-01

    A computer program implements a thrust impulse measurement (TIM) filter, which processes data on changes in velocity and attitude of a spacecraft to estimate the small impulsive forces and torques exerted by the thrusters of the spacecraft reaction control system (RCS). The velocity-change data are obtained from line-of-sight-velocity data from Doppler measurements made from the Earth. The attitude-change data are the telemetered from an inertial measurement unit (IMU) aboard the spacecraft. The TIM filter estimates the threeaxis thrust vector for each RCS thruster, thereby enabling reduction of cumulative navigation error attributable to inaccurate prediction of thrust vectors. The filter has been augmented with a simple mathematical model to compensate for large temperature fluctuations in the spacecraft thruster catalyst bed in order to estimate thrust more accurately at deadbanding cold-firing levels. Also, rigorous consider-covariance estimation is applied in the TIM to account for the expected uncertainty in the moment of inertia and the location of the center of gravity of the spacecraft. The TIM filter was built with, and depends upon, a sigma-point consider-filter algorithm implemented in a Python-language computer program.

  11. Stereo and IMU-Assisted Visual Odometry for Small Robots

    Science.gov (United States)

    2012-01-01

    This software performs two functions: (1) taking stereo image pairs as input, it computes stereo disparity maps from them by cross-correlation to achieve 3D (three-dimensional) perception; (2) taking a sequence of stereo image pairs as input, it tracks features in the image sequence to estimate the motion of the cameras between successive image pairs. A real-time stereo vision system with IMU (inertial measurement unit)-assisted visual odometry was implemented on a single 750 MHz/520 MHz OMAP3530 SoC (system on chip) from TI (Texas Instruments). Frame rates of 46 fps (frames per second) were achieved at QVGA (Quarter Video Graphics Array i.e. 320 240), or 8 fps at VGA (Video Graphics Array 640 480) resolutions, while simultaneously tracking up to 200 features, taking full advantage of the OMAP3530's integer DSP (digital signal processor) and floating point ARM processors. This is a substantial advancement over previous work as the stereo implementation produces 146 Mde/s (millions of disparities evaluated per second) in 2.5W, yielding a stereo energy efficiency of 58.8 Mde/J, which is 3.75 better than prior DSP stereo while providing more functionality.

  12. IMU-based joint angle measurement for gait analysis.

    Science.gov (United States)

    Seel, Thomas; Raisch, Jörg; Schauer, Thomas

    2014-04-16

    This contribution is concerned with joint angle calculation based on inertial measurement data in the context of human motion analysis. Unlike most robotic devices, the human body lacks even surfaces and right angles. Therefore, we focus on methods that avoid assuming certain orientations in which the sensors are mounted with respect to the body segments. After a review of available methods that may cope with this challenge, we present a set of new methods for: (1) joint axis and position identification; and (2) flexion/extension joint angle measurement. In particular, we propose methods that use only gyroscopes and accelerometers and, therefore, do not rely on a homogeneous magnetic field. We provide results from gait trials of a transfemoral amputee in which we compare the inertial measurement unit (IMU)-based methods to an optical 3D motion capture system. Unlike most authors, we place the optical markers on anatomical landmarks instead of attaching them to the IMUs. Root mean square errors of the knee flexion/extension angles are found to be less than 1° on the prosthesis and about 3° on the human leg. For the plantar/dorsiflexion of the ankle, both deviations are about 1°.

  13. Determination Method of Bridge Rotation Angle Response Using MEMS IMU

    Directory of Open Access Journals (Sweden)

    Hidehiko Sekiya

    2016-11-01

    Full Text Available To implement steel bridge maintenance, especially that related to fatigue damage, it is important to monitor bridge deformations under traffic conditions. Bridges deform and rotate differently under traffic load conditions because their structures differ in terms of length and flexibility. Such monitoring enables the identification of the cause of stress concentrations that cause fatigue damage and the proposal of appropriate countermeasures. However, although bridge deformation monitoring requires observations of bridge angle response as well as the bridge displacement response, measuring the rotation angle response of a bridge subject to traffic loads is difficult. Theoretically, the rotation angle response can be calculated by integrating the angular velocity, but for field measurements of actual in-service bridges, estimating the necessary boundary conditions would be difficult due to traffic-induced vibration. To solve the problem, this paper proposes a method for determining the rotation angle response of an in-service bridge from its angular velocity, as measured by a inertial measurement unit (IMU. To verify our proposed method, field measurements were conducted using nine micro-electrical mechanical systems (MEMS IMUs and two contact displacement gauges. The results showed that our proposed method provided high accuracy when compared to the reference responses calculated by the contact displacement gauges.

  14. Estimation of Antenna Pose in the Earth Frame Using Camera and IMU Data from Mobile Phones

    Science.gov (United States)

    Wang, Zhen; Jin, Bingwen; Geng, Weidong

    2017-01-01

    The poses of base station antennas play an important role in cellular network optimization. Existing methods of pose estimation are based on physical measurements performed either by tower climbers or using additional sensors attached to antennas. In this paper, we present a novel non-contact method of antenna pose measurement based on multi-view images of the antenna and inertial measurement unit (IMU) data captured by a mobile phone. Given a known 3D model of the antenna, we first estimate the antenna pose relative to the phone camera from the multi-view images and then employ the corresponding IMU data to transform the pose from the camera coordinate frame into the Earth coordinate frame. To enhance the resulting accuracy, we improve existing camera-IMU calibration models by introducing additional degrees of freedom between the IMU sensors and defining a new error metric based on both the downtilt and azimuth angles, instead of a unified rotational error metric, to refine the calibration. In comparison with existing camera-IMU calibration methods, our method achieves an improvement in azimuth accuracy of approximately 1.0 degree on average while maintaining the same level of downtilt accuracy. For the pose estimation in the camera coordinate frame, we propose an automatic method of initializing the optimization solver and generating bounding constraints on the resulting pose to achieve better accuracy. With this initialization, state-of-the-art visual pose estimation methods yield satisfactory results in more than 75% of cases when plugged into our pipeline, and our solution, which takes advantage of the constraints, achieves even lower estimation errors on the downtilt and azimuth angles, both on average (0.13 and 0.3 degrees lower, respectively) and in the worst case (0.15 and 7.3 degrees lower, respectively), according to an evaluation conducted on a dataset consisting of 65 groups of data. We show that both of our enhancements contribute to the performance

  15. Stable Tactical-Grade MEMS IMU for Spin-Stabilized Rockets Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An Integrated MEMS IMU is proposed that will operate effectively in a spinning rocket up to 7 revs/sec. The IMU contains three gyroscopes and nine accelerometers on...

  16. SmallSat Precision Navigation with Low-Cost MEMS IMU Swarms

    Science.gov (United States)

    Christian, John; Bishop, Robert; Martinez, Andres; Petro, Andrew

    2015-01-01

    The continued advancement of small satellite-based science missions requires the solution to a number of important technical challenges. Of particular note is that small satellite missions are characterized by tight constraints on cost, mass, power, and volume that make them unable to fly the high-quality Inertial Measurement Units (IMUs) required for orbital missions demanding precise orientation and positioning. Instead, small satellite missions typically fly low-cost Micro-Electro-Mechanical System (MEMS) IMUs. Unfortunately, the performance characteristics of these MEMS IMUs make them ineffectual in many spaceflight applications when employed in a single IMU system configuration.

  17. GyroWand: An Approach to IMU-Based Raycasting for Augmented Reality.

    Science.gov (United States)

    Hincapié-Ramos, Juan David; Özacar, Kasim; Irani, Pourang P; Kitamura, Yoshifumi

    2016-01-01

    Optical see-through head-mounted displays enable augmented reality (AR) applications that display virtual objects overlaid on the real world. At the core of this new generation of devices are low-cost tracking technologies that allow us to interpret users' motion in the real world in relation to the virtual content for the purposes of navigation and interaction. The advantages of pervasive tracking come at the cost of limiting interaction possibilities, however. To address these challenges the authors introduce GyroWand, a raycasting technique for AR HMDs using inertial measurement unit (IMU) rotational data from a handheld controller.

  18. Drift reduction in strapdown airborne gravimetry using a simple thermal correction

    DEFF Research Database (Denmark)

    Becker, David; Nielsen, J. Emil; Ayres-Sampaio, Diogo;

    2015-01-01

    Previous work has shown, that strapdown airborne gravimeters can have a comparable or even superior performance in the higher frequency domain (resolution of few kilometres), compared to classical stable-platform air gravimeters using springs, such as the LaCoste and Romberg (LCR) S-gravimeter. H...

  19. Monitoring High-Frequency Ocean Signals Using Low-Cost Gnss/imu Buoys

    Science.gov (United States)

    Huang, Yu-Lun; Kuo, Chung-Yen; Shih, Chiao-Hui; Lin, Li-Ching; Chiang, Kai-wei; Cheng, Kai-Chien

    2016-06-01

    In oceans there are different ocean signals covering the multi-frequencies including tsunami, meteotsunami, storm surge, as sea level change, and currents. These signals have the direct and significant impact on the economy and life of human-beings. Therefore, measuring ocean signals accurately becomes more and more important and necessary. Nowadays, there are many techniques and methods commonly used for monitoring oceans, but each has its limitation. For example, tide gauges only measure sea level relative to benchmarks and are disturbed unevenly, and satellite altimeter measurements are not continuous and inaccurate near coastal oceans. In addition, high-frequency ocean signals such as tsunami and meteotsunami cannot be sufficiently detected by 6-minutes tide gauge measurements or 10-day sampled altimetry data. Moreover, traditional accelerometer buoy is heavy, expensive and the low-frequency noise caused by the instrument is unavoidable. In this study, a small, low-cost and self-assembly autonomous Inertial Measurement Unit (IMU) that independently collects continuous acceleration and angular velocity data is mounted on a GNSS buoy to provide the positions and tilts of the moving buoy. The main idea is to integrate the Differential GNSS (DGNSS) or Precise Point Positioning (PPP) solutions with IMU data, and then evaluate the performance by comparing with in situ tide gauges. The validation experiments conducted in the NCKU Tainan Hydraulics Laboratory showed that GNSS and IMU both can detect the simulated regular wave frequency and height, and the field experiments in the Anping Harbor, Tainan, Taiwan showed that the low-cost GNSS buoy has an excellent ability to observe significant wave heights in amplitude and frequency.

  20. Implementation of an IMU Aided Image Stacking Algorithm in a Digital Camera for Unmanned Aerial Vehicles

    Directory of Open Access Journals (Sweden)

    Ahmad Audi

    2017-07-01

    Full Text Available Images acquired with a long exposure time using a camera embedded on UAVs (Unmanned Aerial Vehicles exhibit motion blur due to the erratic movements of the UAV. The aim of the present work is to be able to acquire several images with a short exposure time and use an image processing algorithm to produce a stacked image with an equivalent long exposure time. Our method is based on the feature point image registration technique. The algorithm is implemented on the light-weight IGN (Institut national de l’information géographique camera, which has an IMU (Inertial Measurement Unit sensor and an SoC (System on Chip/FPGA (Field-Programmable Gate Array. To obtain the correct parameters for the resampling of the images, the proposed method accurately estimates the geometrical transformation between the first and the N-th images. Feature points are detected in the first image using the FAST (Features from Accelerated Segment Test detector, then homologous points on other images are obtained by template matching using an initial position benefiting greatly from the presence of the IMU sensor. The SoC/FPGA in the camera is used to speed up some parts of the algorithm in order to achieve real-time performance as our ultimate objective is to exclusively write the resulting image to save bandwidth on the storage device. The paper includes a detailed description of the implemented algorithm, resource usage summary, resulting processing time, resulting images and block diagrams of the described architecture. The resulting stacked image obtained for real surveys does not seem visually impaired. An interesting by-product of this algorithm is the 3D rotation estimated by a photogrammetric method between poses, which can be used to recalibrate in real time the gyrometers of the IMU. Timing results demonstrate that the image resampling part of this algorithm is the most demanding processing task and should also be accelerated in the FPGA in future work.

  1. MONITORING HIGH-FREQUENCY OCEAN SIGNALS USING LOW-COST GNSS/IMU BUOYS

    Directory of Open Access Journals (Sweden)

    Y.-L. Huang

    2016-06-01

    Full Text Available In oceans there are different ocean signals covering the multi-frequencies including tsunami, meteotsunami, storm surge, as sea level change, and currents. These signals have the direct and significant impact on the economy and life of human-beings. Therefore, measuring ocean signals accurately becomes more and more important and necessary. Nowadays, there are many techniques and methods commonly used for monitoring oceans, but each has its limitation. For example, tide gauges only measure sea level relative to benchmarks and are disturbed unevenly, and satellite altimeter measurements are not continuous and inaccurate near coastal oceans. In addition, high-frequency ocean signals such as tsunami and meteotsunami cannot be sufficiently detected by 6-minutes tide gauge measurements or 10-day sampled altimetry data. Moreover, traditional accelerometer buoy is heavy, expensive and the low-frequency noise caused by the instrument is unavoidable. In this study, a small, low-cost and self-assembly autonomous Inertial Measurement Unit (IMU that independently collects continuous acceleration and angular velocity data is mounted on a GNSS buoy to provide the positions and tilts of the moving buoy. The main idea is to integrate the Differential GNSS (DGNSS or Precise Point Positioning (PPP solutions with IMU data, and then evaluate the performance by comparing with in situ tide gauges. The validation experiments conducted in the NCKU Tainan Hydraulics Laboratory showed that GNSS and IMU both can detect the simulated regular wave frequency and height, and the field experiments in the Anping Harbor, Tainan, Taiwan showed that the low-cost GNSS buoy has an excellent ability to observe significant wave heights in amplitude and frequency.

  2. Implementation of an IMU Aided Image Stacking Algorithm in a Digital Camera for Unmanned Aerial Vehicles.

    Science.gov (United States)

    Audi, Ahmad; Pierrot-Deseilligny, Marc; Meynard, Christophe; Thom, Christian

    2017-07-18

    Images acquired with a long exposure time using a camera embedded on UAVs (Unmanned Aerial Vehicles) exhibit motion blur due to the erratic movements of the UAV. The aim of the present work is to be able to acquire several images with a short exposure time and use an image processing algorithm to produce a stacked image with an equivalent long exposure time. Our method is based on the feature point image registration technique. The algorithm is implemented on the light-weight IGN (Institut national de l'information géographique) camera, which has an IMU (Inertial Measurement Unit) sensor and an SoC (System on Chip)/FPGA (Field-Programmable Gate Array). To obtain the correct parameters for the resampling of the images, the proposed method accurately estimates the geometrical transformation between the first and the N-th images. Feature points are detected in the first image using the FAST (Features from Accelerated Segment Test) detector, then homologous points on other images are obtained by template matching using an initial position benefiting greatly from the presence of the IMU sensor. The SoC/FPGA in the camera is used to speed up some parts of the algorithm in order to achieve real-time performance as our ultimate objective is to exclusively write the resulting image to save bandwidth on the storage device. The paper includes a detailed description of the implemented algorithm, resource usage summary, resulting processing time, resulting images and block diagrams of the described architecture. The resulting stacked image obtained for real surveys does not seem visually impaired. An interesting by-product of this algorithm is the 3D rotation estimated by a photogrammetric method between poses, which can be used to recalibrate in real time the gyrometers of the IMU. Timing results demonstrate that the image resampling part of this algorithm is the most demanding processing task and should also be accelerated in the FPGA in future work.

  3. Pose estimation of surgical instrument using sensor data fusion with optical tracker and IMU based on Kalman filter

    Directory of Open Access Journals (Sweden)

    Oh Hyunmin

    2015-01-01

    Full Text Available Tracking system is essential for Image Guided Surgery(IGS. The Optical Tracking Sensor(OTS has been widely used as tracking system for IGS due to its high accuracy and easy usage. However, OTS has a limit that tracking fails when occlusion of marker occurs. In this paper, sensor fusion with OTS and Inertial Measurement Unit(IMU is proposed to solve this problem. The proposed algorithm improves the accuracy of tracking system by eliminating scattering error of the sensor and supplements the disadvantages of OTS and IMU through sensor fusion based on Kalman filter. Also, coordinate axis calibration method that improves the accuracy is introduced. The performed experiment verifies the effectualness of the proposed algorithm.

  4. A cascaded two-step Kalman filter for estimation of human body segment orientation using MEMS-IMU.

    Science.gov (United States)

    Zihajehzadeh, S; Loh, D; Lee, M; Hoskinson, R; Park, E J

    2014-01-01

    Orientation of human body segments is an important quantity in many biomechanical analyses. To get robust and drift-free 3-D orientation, raw data from miniature body worn MEMS-based inertial measurement units (IMU) should be blended in a Kalman filter. Aiming at less computational cost, this work presents a novel cascaded two-step Kalman filter orientation estimation algorithm. Tilt angles are estimated in the first step of the proposed cascaded Kalman filter. The estimated tilt angles are passed to the second step of the filter for yaw angle calculation. The orientation results are benchmarked against the ones from a highly accurate tactical grade IMU. Experimental results reveal that the proposed algorithm provides robust orientation estimation in both kinematically and magnetically disturbed conditions.

  5. Passive FOG IMU for short-range missile application: from qualification toward series production

    Science.gov (United States)

    Trommer, Gert F.; Mueller, R.; Opitz, S.

    1996-11-01

    An inertial measurement unit (IMU) with angular rate, angular increment and linear acceleration measurement systems for short range missile application is described. It consists of a three axis fiber optic gyroscope (FOG) cluster, three linear vibrating beam accelerometers and an electronics device for signal evaluation and data transmission via a serial transputer link. The FOG cluster is realized by means of a passive all-fiber open loop configuration. Due to the inherent optical phase shift of 3 by 3 couplers, completely passive operation near the quadrature point is achieved without the need for a non- reciprocal optical phase modulation in the fiber loop. Basing on that concept more than 50 rugged IMUs have been built for implementation into a short range air to air missile. Verification tests for flight clearance with stresses simulating air carriage and missile free flight environments have been computed. The operation under extreme vibration and shock environments without the use of vibration isolator fixings due to very tight requirements on data time delay has been demonstrated. The first telemetered missile firings have been performed successfully. The line- setup for large quantity series production is progressing. The implementation of the workstations for the integration of the IMU is finished. The production equipment for calibration and acceptance testing of IMUs in parallel allowing for a rate of more than 150 unit per month has been installed and will be operational in autumn this year.

  6. Individualized Mathematics Teaching. Results from the IMU Project in Sweden.

    Science.gov (United States)

    Larsson, Inger

    The Individual Mathematics Teaching Project (IMU) has been under development in the upper level (grades 7-9) of the comprehensive school in Sweden since 1964. Its goals are (1) to construct and test self-instruction study material in mathematics, (2) to find suitable teaching methods and work forms for the use of this material, (3) to try out…

  7. Evaluating IMU communication skills training programme: assessment tool development.

    Science.gov (United States)

    Yeap, R; Beevi, Z; Lukman, H

    2008-08-01

    This article describes the development of four assessment tools designed to evaluate the communication skills training (CST) programme at the International Medical University (IMU). The tools measure pre-clinical students' 1) perceived competency in basic interpersonal skills, 2) attitude towards patient-centred communication, 3) conceptual knowledge on doctor-patient communication, and 4) acceptance of the CST programme.

  8. Wavelet based automated postural event detection and activity classification with single imu - biomed 2013.

    Science.gov (United States)

    Lockhart, Thurmon E; Soangra, Rahul; Zhang, Jian; Wu, Xuefan

    2013-01-01

    Mobility characteristics associated with activity of daily living such as sitting down, lying down, rising up, and walking are considered to be important in maintaining functional independence and healthy life style especially for the growing elderly population. Characteristics of postural transitions such as sit-to-stand are widely used by clinicians as a physical indicator of health, and walking is used as an important mobility assessment tool. Many tools have been developed to assist in the assessment of functional levels and to detect a person’s activities during daily life. These include questionnaires, observation, diaries, kinetic and kinematic systems, and validated functional tests. These measures are costly and time consuming, rely on subjective patient recall and may not accurately reflect functional ability in the patient’s home. In order to provide a low-cost, objective assessment of functional ability, inertial measurement unit (IMU) using MEMS technology has been employed to ascertain ADLs. These measures facilitate long-term monitoring of activity of daily living using wearable sensors. IMU system are desirable in monitoring human postures since they respond to both frequency and the intensity of movements and measure both dc (gravitational acceleration vector) and ac (acceleration due to body movement) components at a low cost. This has enabled the development of a small, lightweight, portable system that can be worn by a free-living subject without motion impediment – TEMPO (Technology Enabled Medical Precision Observation). Using this IMU system, we acquired indirect measures of biomechanical variables that can be used as an assessment of individual mobility characteristics with accuracy and recognition rates that are comparable to the modern motion capture systems. In this study, five subjects performed various ADLs and mobility measures such as posture transitions and gait characteristics were obtained. We developed postural event detection

  9. IMU-based ambulatory walking speed estimation in constrained treadmill and overground walking.

    Science.gov (United States)

    Yang, Shuozhi; Li, Qingguo

    2012-01-01

    This study evaluated the performance of a walking speed estimation system based on using an inertial measurement unit (IMU), a combination of accelerometers and gyroscopes. The walking speed estimation algorithm segments the walking sequence into individual stride cycles (two steps) based on the inverted pendulum-like behaviour of the stance leg during walking and it integrates the angular velocity and linear accelerations of the shank to determine the displacement of each stride. The evaluation was performed in both treadmill and overground walking experiments with various constraints on walking speed, step length and step frequency to provide a relatively comprehensive assessment of the system. Promising results were obtained in providing accurate and consistent walking speed/step length estimation in different walking conditions. An overall percentage root mean squared error (%RMSE) of 4.2 and 4.0% was achieved in treadmill and overground walking experiments, respectively. With an increasing interest in understanding human walking biomechanics, the IMU-based ambulatory system could provide a useful walking speed/step length measurement/control tool for constrained walking studies.

  10. Equipping an FPGA-Based Mars Rover With an LN-200 IMU

    Science.gov (United States)

    Zola, Nicholas J.

    2005-01-01

    The Mars Exploration Rovers (MER) currently navigating the surface of Mars are outfitted with an advanced stereovision correlation algorithm which allows them to "see" three-dimensionally and autonomously avoid obstac'les in their path. A bottleneck of this system is that it is computationally intense and requires 3 minutes of processing for every correlated image and path choice. Taking advantage of the optimization and reprogrammability of FPGAs, the Mobility Avionics lab has reduced this process to under a second. The lab is demonstrating the advancement with a prototype rover, complete with an LN-200 inertial measurement unit (IMU), which is a flight spare from MER. The LN-200 is a space-grade, six degrees-of-freedom IMU using three fiber-optic gyroscopes and three silicon accelerometers and no moving parts. It has particular power-sequencing needs and communicates with a specialized serial protocol (SDLC over RS-422), requiring specific hardware and software for proper functionality and interfacing with an FPGA. The process of incorporating the LN-200 into the system is described herein.

  11. Georeferencing in Gnss-Challenged Environment: Integrating Uwb and Imu Technologies

    Science.gov (United States)

    Toth, C. K.; Koppanyi, Z.; Navratil, V.; Grejner-Brzezinska, D.

    2017-05-01

    Acquiring geospatial data in GNSS compromised environments remains a problem in mapping and positioning in general. Urban canyons, heavily vegetated areas, indoor environments represent different levels of GNSS signal availability from weak to no signal reception. Even outdoors, with multiple GNSS systems, with an ever-increasing number of satellites, there are many situations with limited or no access to GNSS signals. Independent navigation sensors, such as IMU can provide high-data rate information but their initial accuracy degrades quickly, as the measurement data drift over time unless positioning fixes are provided from another source. At The Ohio State University's Satellite Positioning and Inertial Navigation (SPIN) Laboratory, as one feasible solution, Ultra- Wideband (UWB) radio units are used to aid positioning and navigating in GNSS compromised environments, including indoor and outdoor scenarios. Here we report about experiences obtained with georeferencing a pushcart based sensor system under canopied areas. The positioning system is based on UWB and IMU sensor integration, and provides sensor platform orientation for an electromagnetic inference (EMI) sensor. Performance evaluation results are provided for various test scenarios, confirming acceptable results for applications where high accuracy is not required.

  12. Integrity monitoring of vehicle positioning in urban environment using RTK-GNSS, IMU and speedometer

    Science.gov (United States)

    El-Mowafy, Ahmed; Kubo, Nobuaki

    2017-05-01

    Continuous and trustworthy positioning is a critical capability for advanced driver assistance systems (ADAS). To achieve continuous positioning, methods such as global navigation satellite systems real-time kinematic (RTK), Doppler-based positioning, and positioning using low-cost inertial measurement unit (IMU) with car speedometer data are combined in this study. To ensure reliable positioning, the system should have integrity monitoring above a certain level, such as 99%. Achieving this level when combining different types of measurements that have different characteristics and different types of errors is a challenge. In this study, a novel integrity monitoring approach is presented for the proposed integrated system. A threat model of the measurements of the system components is discussed, which includes both the nominal performance and possible fault modes. A new protection level is presented to bound the maximum directional position error. The proposed approach was evaluated through a kinematic test in an urban area in Japan with a focus on horizontal positioning. Test results show that by integrating RTK, Doppler with IMU/speedometer, 100% positioning availability was achieved. The integrity monitoring availability was assessed and found to meet the target value where the position errors were bounded by the protection level, which was also less than an alert level, indicating the effectiveness of the proposed approach.

  13. GEOREFERENCING IN GNSS-CHALLENGED ENVIRONMENT: INTEGRATING UWB AND IMU TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    C. K. Toth

    2017-05-01

    Full Text Available Acquiring geospatial data in GNSS compromised environments remains a problem in mapping and positioning in general. Urban canyons, heavily vegetated areas, indoor environments represent different levels of GNSS signal availability from weak to no signal reception. Even outdoors, with multiple GNSS systems, with an ever-increasing number of satellites, there are many situations with limited or no access to GNSS signals. Independent navigation sensors, such as IMU can provide high-data rate information but their initial accuracy degrades quickly, as the measurement data drift over time unless positioning fixes are provided from another source. At The Ohio State University’s Satellite Positioning and Inertial Navigation (SPIN Laboratory, as one feasible solution, Ultra- Wideband (UWB radio units are used to aid positioning and navigating in GNSS compromised environments, including indoor and outdoor scenarios. Here we report about experiences obtained with georeferencing a pushcart based sensor system under canopied areas. The positioning system is based on UWB and IMU sensor integration, and provides sensor platform orientation for an electromagnetic inference (EMI sensor. Performance evaluation results are provided for various test scenarios, confirming acceptable results for applications where high accuracy is not required.

  14. Development of an indoor positioning and navigation system using monocular SLAM and IMU

    Science.gov (United States)

    Mai, Yu-Ching; Lai, Ying-Chih

    2016-07-01

    The positioning and navigation systems based on Global Positioning System (GPS) have been developed over past decades and have been widely used for outdoor environment. However, high-rise buildings or indoor environments can block the satellite signal. Therefore, many indoor positioning methods have been developed to respond to this issue. In addition to the distance measurements using sonar and laser sensors, this study aims to develop a method by integrating a monocular simultaneous localization and mapping (MonoSLAM) algorithm with an inertial measurement unit (IMU) to build an indoor positioning system. The MonoSLAM algorithm measures the distance (depth) between the image features and the camera. With the help of Extend Kalman Filter (EKF), MonoSLAM can provide real-time position, velocity and camera attitude in world frame. Since the feature points will not always appear and can't be trusted at any time, a wrong estimation of the features will cause the estimated position diverge. To overcome this problem, a multisensor fusion algorithm was applied in this study by using the multi-rate Kalman Filter. Finally, from the experiment results, the proposed system was verified to be able to improve the reliability and accuracy of the MonoSLAM by integrating the IMU measurements.

  15. A Multi-Sensor Fusion MAV State Estimation from Long-Range Stereo, IMU, GPS and Barometric Sensors.

    Science.gov (United States)

    Song, Yu; Nuske, Stephen; Scherer, Sebastian

    2016-12-22

    State estimation is the most critical capability for MAV (Micro-Aerial Vehicle) localization, autonomous obstacle avoidance, robust flight control and 3D environmental mapping. There are three main challenges for MAV state estimation: (1) it can deal with aggressive 6 DOF (Degree Of Freedom) motion; (2) it should be robust to intermittent GPS (Global Positioning System) (even GPS-denied) situations; (3) it should work well both for low- and high-altitude flight. In this paper, we present a state estimation technique by fusing long-range stereo visual odometry, GPS, barometric and IMU (Inertial Measurement Unit) measurements. The new estimation system has two main parts, a stochastic cloning EKF (Extended Kalman Filter) estimator that loosely fuses both absolute state measurements (GPS, barometer) and the relative state measurements (IMU, visual odometry), and is derived and discussed in detail. A long-range stereo visual odometry is proposed for high-altitude MAV odometry calculation by using both multi-view stereo triangulation and a multi-view stereo inverse depth filter. The odometry takes the EKF information (IMU integral) for robust camera pose tracking and image feature matching, and the stereo odometry output serves as the relative measurements for the update of the state estimation. Experimental results on a benchmark dataset and our real flight dataset show the effectiveness of the proposed state estimation system, especially for the aggressive, intermittent GPS and high-altitude MAV flight.

  16. QUALITY ASSESSMENT OF COMBINED IMU/GNSS DATA FOR DIRECT GEOREFERENCING IN THE CONTEXT OF UAV-BASED MAPPING

    Directory of Open Access Journals (Sweden)

    C. Stöcker

    2017-08-01

    Full Text Available Within the past years, the development of high-quality Inertial Measurement Units (IMU and GNSS technology and dedicated RTK (Real Time Kinematic and PPK (Post-Processing Kinematic solutions for UAVs promise accurate measurements of the exterior orientation (EO parameters which allow to georeference the images. Whereas the positive impact of known precise GNSS coordinates of camera positions is already well studied, the influence of the angular observations have not been studied in depth so far. Challenges include accuracies of GNSS/IMU observations, excessive angular motion and time synchronization problems during the flight. Thus, this study assesses the final geometric accuracy using direct georeferencing with high-quality post-processed IMU/GNSS and PPK corrections. A comparison of different data processing scenarios including indirect georeferencing, integrated solutions as well as direct georeferencing provides guidance on the workability of UAV mapping approaches that require a high level of positional accuracy. In the current research the results show, that the use of the post-processed APX-15 GNSS and IMU data was particularly beneficial to enhance the image orientation quality. Horizontal accuracies within the pixel level (2.8 cm could be achieved. However, it was also shown, that the angular EO parameters are still too inaccurate to be assigned with a high weight during the image orientation process. Furthermore, detailed investigations of the EO parameters unveil that systematic sensor misalignments and offsets of the image block can be reduced by the introduction of four GCPs. In this regard, the use of PPK corrections reduces the time consuming field work to measure high quantities of GCPs and makes large-scale UAV mapping a more feasible solution for practitioners that require high geometric accuracies.

  17. IMU/DGPS辅助航空摄影新技术的应用%THE APPLICATION OF IMU/DGPS-SUPPORTED PHOTOGRAMMETRY

    Institute of Scientific and Technical Information of China (English)

    郭大海; 吴立新; 王建超; 郑雄伟

    2006-01-01

    利用IMU/DGPS组合导航技术,可以在航空摄影的同时直接获取像片的外方位元素.试验表明,只要对IMU/DGPS与航摄仪的集成系统误差和漂移误差进行检校和改正,直接获取的像片外方位元素可以用于正射影像的制作和中小比例尺测图.本文首先讨论了IMU/DGPS组合导航技术和IMU/DGPS辅助航空摄影系统的工作原理;然后,结合甘肃酒泉试验数据,重点分析讨论了IMU/DGPS和航摄仪集成系统的误差及其检校问题.

  18. Accuracy assessment of the integration of GNSS and a MEMS IMU in a terrestrial platform.

    Science.gov (United States)

    Madeira, Sergio; Yan, Wenlin; Bastos, Luísa; Gonçalves, José A

    2014-11-04

    MEMS Inertial Measurement Units are available at low cost and can replace expensive units in mobile mapping platforms which need direct georeferencing. This is done through the integration with GNSS measurements in order to achieve a continuous positioning solution and to obtain orientation angles. This paper presents the results of the assessment of the accuracy of a system that integrates GNSS and a MEMS IMU in a terrestrial platform. We describe the methodology used and the tests realized where the accuracy of the positions and orientation parameters were assessed using an independent photogrammetric technique employing cameras that integrate the mobile mapping system developed by the authors. Results for the accuracy of attitude angles and coordinates show that accuracies better than a decimeter in positions, and under a degree in angles, can be achieved even considering that the terrestrial platform is operating in less than favorable environments.

  19. FDIR for the IMU Component of AOCS Systems

    Directory of Open Access Journals (Sweden)

    Maurício N. Pontuschka

    2014-01-01

    Full Text Available The main objective of this paper is the study of a FDIR for an IMU aiming at space applications with focus on the gyro signal analysis and the tests of the filtering algorithms. The algorithms have been tested by using lab data provided by the DMC LABSIM (Physical’s Simulation Laboratory of the Space Mechanics and Control Division of INPE. The results have demonstrated good agreement with the concepts applied in this study. Automatic detection procedures are very important in the characterization of occurrence, definition of criteria, and device types in the scenario of AOCS FDIR. An IMU comprised of four gyros in a tetrahedral configuration is one of the assumed components for the AOCS (attitude and orbit control subsystem considered in this work. The types of failures considered in this paper are the step abrupt change, ramp/drift/slow, stuck, cyclic, erratic, spike, and finally the stuck for variance alteration noise. An appropriate algorithm for the automatic detection of each type of fault is developed. The approach includes the mapping capability of fault event indicators to the IMU. This mapping is very important in the characterization of the occurrence, definition of criteria, and device types as well as associated fault identification for an AOCS.

  20. Research at IMU: achievements, thrust areas and future challenges

    Directory of Open Access Journals (Sweden)

    Wan-Loy Chu

    2013-04-01

    Full Text Available There have been significant achievements inresearch at IMU as indicated by the increasing amountof external funds obtained, and number of publicationsand postgraduate students produced since it startedits research activities in the year 2000. However, it isa great challenge indeed to ensure sustainability ofour research, which is currently heavily dependent oninternal funding. There is a need to realign our strategiesto further enhance our competitiveness in securingexternal funding for research. In line with this, theInstitute for Research, Development and Innovation(IRDI was officially established on 18 September2012. The Institute will serve as a platform to supportall research activities at IMU. There are four Centresof Excellence based on the identified thrust areas underIRDI, namely 1 Centre for Bioactive Molecules andDrug Discovery; 2 Centre for Environmental andPopulation Health; 3 Centre for Cancer and StemCell Research, and 4 Centre for Health ProfessionalEducation Research. Major findings based on research inthese four thrust areas are reviewed in this paper. Withthe strategic planning and establishment of IRDI, it isour aspiration to bring research at IMU to a higher level.

  1. The processing of IMU data in ENTREE implementation and preliminary results

    Science.gov (United States)

    Heck, M. L.

    1980-01-01

    It is demonstrated that the shuttle entry trajectory can be accurately represented in ENTREE with IMU data available postflight. The IMU data consist of platform to body quaternions, and accumulated sensed velocities in mean of fifty (M50) coordinates approximately every second. The preprocessing software required to incorporate the IMU data in ENTREE is described as well as the relatively minor code changes to the ENTREE program itself required to process the IMU data. Code changes to the ENTREE program and input tape data format and content changes are described.

  2. 相对定向的机载惯性测量装置视准轴误差求解方法%A Solving Method for the Boresight Misalignment of Airborne IMU Based on Relative Orientation

    Institute of Scientific and Technical Information of China (English)

    付建红

    2014-01-01

    The boresight misalignment of airborne inertial measurement unit(IMU)is introduced into relative orientation model of aerial stereo image pairs using the inherent relative geometric relationship between aerial images,and a novel method to solve the boresight misalignment of airborne IMU based on relative orientation is proposed.The mathematical models for solving the boresight misalignment of airborne IMU are derived in detail based on a single stereo model and multiple consecutive stereo models,respectively. Then,three sets of actual images obtained with IMU are tested.The empirical results show that the mathe-matical model established is correct and feasible.The boresight misalignment could be solved using multi-ple consecutive stereo models constituted by more than three adjacent aerial images,and the results of direct georeferencing can be improved significantly if using the solved boresight misalignment to compen-sate the exterior angle elements obtained by aerial IMU directly.The method proposed in this paper could avoid many problems brought about by setting calibration field and the other ground control conditions, and it is beneficial for direct and quick georeferencing when using aerial remote sensing equipment with ai rborne IMU.%利用航摄像片存在的相对几何位置关系,将机载 IMU 视准轴误差引入立体像对相对定向模型中,提出一种基于相对定向的机载 IMU 视准轴误差求解新方法。详细推导了基于单个立体模型和连续立体模型求解 IMU 视准轴误差的数学模型,并用3组带有 IMU 设备获取的实际航空影像数据进行了试验验证。结果表明,所推导的机载 IMU 视准轴误差求解方法是正确、可行的,利用3张以上相邻像片构成的连续立体模型即可求解出 IMU 的视准轴误差,用其补偿 IMU 直接测定的外方位角元素,可以使对地目标定位结果得到较大的提高,该方法避免了野外布设检校场和其他地

  3. Improved calibration of IMU biases in analytic coarse alignment for AHRS

    Science.gov (United States)

    Lu, Jiazhen; Lei, Chaohua; Li, Baoguo; Wen, Ting

    2016-07-01

    An improved method for the inertial measurement unit (IMU) calibration of coarse alignment for the low-accuracy attitude heading reference system (AHRS) is proposed in this paper. The sensitivities of the Euler angles with respect to the inertial sensor biases are studied based on the analytic coarse alignment principle, and the errors of earth rotation rate and local gravity in the body frame caused by initial attitude error are analyzed. Then, an improved analytic coarse alignment algorithm with accelerometer and gyro bias calibration in an arbitrary three-position is proposed. Simulation and experiment results show that the novel method can calibrate accelerometer and gyro biases, reduce Euler angle attitude error, and improve navigation precision in practical applications. Moreover, this method can be applied to other low-accuracy inertial navigation systems.

  4. Attitude Estimation and Position Control of VTOL UAVs using IMU and GPS Measurements

    CERN Document Server

    Roberts, Andrew

    2011-01-01

    We address two fundamental problems associated with the control of vertical take-off and landing (VTOL) unmanned airborne vehicles (UAVs): attitude estimation and position control. We propose two velocity-aided attitude observers which utilize a global-positioning system (GPS) in addition to an inertial measurement unit (IMU). The `velocity-aided' class of observer uses an accelerometer to measure the system \\emph{apparent acceleration} (instead of the gravity vector), and is therefore better suited for applications where the rigid-body (aircraft) is subjected to significant linear accelerations (which is to be expected for VTOL UAVs). We also propose a position controller which utilizes the accelerometer in a similar fashion. More precisely, rather than using the system orientation (as is usually done in the existing position controllers), we use the vector measurements (accelerometer and magnetometer measurements) directly in the position control law. Consequently, the proposed position controller does not ...

  5. Kinematic Determination of an Unmodeled Serial Manipulator by Means of an IMU

    Science.gov (United States)

    Ciarleglio, Constance A.

    Kinematic determination for an unmodeled manipulator is usually done through a-priori knowledge of the manipulator physical characteristics or external sensor information. The mathematics of the kinematic estimation, often based on Denavit- Hartenberg convention, are complex and have high computation requirements, in addition to being unique to the manipulator for which the method is developed. Analytical methods that can compute kinematics on-the fly have the potential to be highly beneficial in dynamic environments where different configurations and variable manipulator types are often required. This thesis derives a new screw theory based method of kinematic determination, using a single inertial measurement unit (IMU), for use with any serial, revolute manipulator. The method allows the expansion of reconfigurable manipulator design and simplifies the kinematic process for existing manipulators. A simulation is presented where the theory of the method is verified and characterized with error. The method is then implemented on an existing manipulator as a verification of functionality.

  6. Design of Synchronization IMU/GPS Integrated Navigation System with SAR%与SAR同步的IMU/GPS组合导航系统的设计

    Institute of Scientific and Technical Information of China (English)

    郑鹏思; 李和平; 李建雄

    2009-01-01

    应用IMU/GPS组合导航系统为SAR系统提供运动补偿参数时,数据与SAR之间的同步是非常重要的.基于实际应用提出一种可与SAR系统脉冲重复频率(Pulse Repetition Frequency: PRF)保持同步的IMU/GPS组合导航系统,解决了IMU/GPS组合导航系统不能与SAR同步的问题.

  7. On the Practical Application of IMU/DGPS Supplementary Aerotriangulation%浅谈IMU/DGPS辅助空中三角测量的实际应用

    Institute of Scientific and Technical Information of China (English)

    王西萍; 闵晓凤

    2007-01-01

    目前,IMU/DGPS辅助航空摄影测量技术在国内的应用越来越广.以实际生产为例,介绍了IMU/DGPS辅助空三的特点、作业流程,以及对生产过程中具体问题的处理,总结了IMU/DGPS辅助空三合网平差时应注意的事项,并提出了今后需进一步解决的问题.

  8. Pose estimation of surgical instrument using sensor data fusion with optical tracker and IMU based on Kalman filter

    OpenAIRE

    Oh Hyunmin; Chae You Seong; An Jinung; Kim Min Young

    2015-01-01

    Tracking system is essential for Image Guided Surgery(IGS). The Optical Tracking Sensor(OTS) has been widely used as tracking system for IGS due to its high accuracy and easy usage. However, OTS has a limit that tracking fails when occlusion of marker occurs. In this paper, sensor fusion with OTS and Inertial Measurement Unit(IMU) is proposed to solve this problem. The proposed algorithm improves the accuracy of tracking system by eliminating scattering error of the sensor and supplements the...

  9. TEQC在IMU/DGPS地面基准站数据分析中的应用

    Institute of Scientific and Technical Information of China (English)

    谭荣杰

    2011-01-01

    简单介绍了IMU/DGPS辅助航空摄影测量的工作原理,通过IMU/DGPS在具体工作中的实践,阐述了TEQC的功能与使用方法,重点分析了TEQC在地面基准站的数据检核作用.

  10. 77 FR 808 - Certain Components for Installation of Marine Autopilots With GPS or IMU; Termination of...

    Science.gov (United States)

    2012-01-06

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Certain Components for Installation of Marine Autopilots With GPS or IMU; Termination of... components for installation of marine autopilots with GPS or IMU (i.e., devices for pointing and...

  11. IMU Calibration and Validation in a Factory, Remote on Land and at Sea

    DEFF Research Database (Denmark)

    Jørgensen, Martin Juhl; Paccagnan, Dario; Poulsen, Niels Kjølstad

    2014-01-01

    This paper treats the IMU calibration and validation problem in three settings: Factory production line with the aid of a precision multi-axis turntable, in-the-field on land and at sea, both without specialist test equipment. The treatment is limited to the IMU calibration parameters of key...

  12. 75 FR 59745 - In the Matter of: Certain Components for Installation of Marine Autopilots With GPS or IMU...

    Science.gov (United States)

    2010-09-28

    ... COMMISSION In the Matter of: Certain Components for Installation of Marine Autopilots With GPS or IMU; Notice... of certain installation of marine autopilots with GPS or IMU by reason of infringement of certain... importation of certain components for installation of marine autopilots with GPS or IMU that infringe one...

  13. A study of redundancy management strategy for tetrad strap-down inertial systems. [error detection codes

    Science.gov (United States)

    Hruby, R. J.; Bjorkman, W. S.; Schmidt, S. F.; Carestia, R. A.

    1979-01-01

    Algorithms were developed that attempt to identify which sensor in a tetrad configuration has experienced a step failure. An algorithm is also described that provides a measure of the confidence with which the correct identification was made. Experimental results are presented from real-time tests conducted on a three-axis motion facility utilizing an ortho-skew tetrad strapdown inertial sensor package. The effects of prediction errors and of quantization on correct failure identification are discussed as well as an algorithm for detecting second failures through prediction.

  14. Application of H∞ filtering in the initial alignment of strapdown inertial navigation system

    Institute of Scientific and Technical Information of China (English)

    YU Fei; SUN Feng

    2005-01-01

    In this paper , the principle of H∞ filtering is discussed and H∞ filter is constructed, which is used in the initial alignment of the strapdown inertial navigation systems(SINS). The error model of SINS is derived. By utilizing constructed H∞ filter, the filtering calculation to that system has been conducted. The simulation results of the misalignment angle are given under the condition of unknown noises. The results show that the process of alignment with H∞ filter is much faster and with excellent robustness.

  15. Rigorous Performance Evaluation of Smartphone GNSS/IMU Sensors for ITS Applications.

    Science.gov (United States)

    Gikas, Vassilis; Perakis, Harris

    2016-08-05

    With the rapid growth in smartphone technologies and improvement in their navigation sensors, an increasing amount of location information is now available, opening the road to the provision of new Intelligent Transportation System (ITS) services. Current smartphone devices embody miniaturized Global Navigation Satellite System (GNSS), Inertial Measurement Unit (IMU) and other sensors capable of providing user position, velocity and attitude. However, it is hard to characterize their actual positioning and navigation performance capabilities due to the disparate sensor and software technologies adopted among manufacturers and the high influence of environmental conditions, and therefore, a unified certification process is missing. This paper presents the analysis results obtained from the assessment of two modern smartphones regarding their positioning accuracy (i.e., precision and trueness) capabilities (i.e., potential and limitations) based on a practical but rigorous methodological approach. Our investigation relies on the results of several vehicle tracking (i.e., cruising and maneuvering) tests realized through comparing smartphone obtained trajectories and kinematic parameters to those derived using a high-end GNSS/IMU system and advanced filtering techniques. Performance testing is undertaken for the HTC One S (Android) and iPhone 5s (iOS). Our findings indicate that the deviation of the smartphone locations from ground truth (trueness) deteriorates by a factor of two in obscured environments compared to those derived in open sky conditions. Moreover, it appears that iPhone 5s produces relatively smaller and less dispersed error values compared to those computed for HTC One S. Also, the navigation solution of the HTC One S appears to adapt faster to changes in environmental conditions, suggesting a somewhat different data filtering approach for the iPhone 5s. Testing the accuracy of the accelerometer and gyroscope sensors for a number of maneuvering

  16. Rigorous Performance Evaluation of Smartphone GNSS/IMU Sensors for ITS Applications

    Directory of Open Access Journals (Sweden)

    Vassilis Gikas

    2016-08-01

    Full Text Available With the rapid growth in smartphone technologies and improvement in their navigation sensors, an increasing amount of location information is now available, opening the road to the provision of new Intelligent Transportation System (ITS services. Current smartphone devices embody miniaturized Global Navigation Satellite System (GNSS, Inertial Measurement Unit (IMU and other sensors capable of providing user position, velocity and attitude. However, it is hard to characterize their actual positioning and navigation performance capabilities due to the disparate sensor and software technologies adopted among manufacturers and the high influence of environmental conditions, and therefore, a unified certification process is missing. This paper presents the analysis results obtained from the assessment of two modern smartphones regarding their positioning accuracy (i.e., precision and trueness capabilities (i.e., potential and limitations based on a practical but rigorous methodological approach. Our investigation relies on the results of several vehicle tracking (i.e., cruising and maneuvering tests realized through comparing smartphone obtained trajectories and kinematic parameters to those derived using a high-end GNSS/IMU system and advanced filtering techniques. Performance testing is undertaken for the HTC One S (Android and iPhone 5s (iOS. Our findings indicate that the deviation of the smartphone locations from ground truth (trueness deteriorates by a factor of two in obscured environments compared to those derived in open sky conditions. Moreover, it appears that iPhone 5s produces relatively smaller and less dispersed error values compared to those computed for HTC One S. Also, the navigation solution of the HTC One S appears to adapt faster to changes in environmental conditions, suggesting a somewhat different data filtering approach for the iPhone 5s. Testing the accuracy of the accelerometer and gyroscope sensors for a number of

  17. Rigorous Performance Evaluation of Smartphone GNSS/IMU Sensors for ITS Applications

    Science.gov (United States)

    Gikas, Vassilis; Perakis, Harris

    2016-01-01

    With the rapid growth in smartphone technologies and improvement in their navigation sensors, an increasing amount of location information is now available, opening the road to the provision of new Intelligent Transportation System (ITS) services. Current smartphone devices embody miniaturized Global Navigation Satellite System (GNSS), Inertial Measurement Unit (IMU) and other sensors capable of providing user position, velocity and attitude. However, it is hard to characterize their actual positioning and navigation performance capabilities due to the disparate sensor and software technologies adopted among manufacturers and the high influence of environmental conditions, and therefore, a unified certification process is missing. This paper presents the analysis results obtained from the assessment of two modern smartphones regarding their positioning accuracy (i.e., precision and trueness) capabilities (i.e., potential and limitations) based on a practical but rigorous methodological approach. Our investigation relies on the results of several vehicle tracking (i.e., cruising and maneuvering) tests realized through comparing smartphone obtained trajectories and kinematic parameters to those derived using a high-end GNSS/IMU system and advanced filtering techniques. Performance testing is undertaken for the HTC One S (Android) and iPhone 5s (iOS). Our findings indicate that the deviation of the smartphone locations from ground truth (trueness) deteriorates by a factor of two in obscured environments compared to those derived in open sky conditions. Moreover, it appears that iPhone 5s produces relatively smaller and less dispersed error values compared to those computed for HTC One S. Also, the navigation solution of the HTC One S appears to adapt faster to changes in environmental conditions, suggesting a somewhat different data filtering approach for the iPhone 5s. Testing the accuracy of the accelerometer and gyroscope sensors for a number of maneuvering

  18. Replacement of Imu-Cmu intron by NeoR gene alters Imu germ-line expression but has no effect on V(D)J recombination.

    Science.gov (United States)

    Haddad, Dania; Dougier, Hei-Lanne; Laviolette, Nathalie; Puget, Nadine; Khamlichi, Ahmed Amine

    2010-02-01

    The NeoR gene has often been used to unravel the mechanisms underlying long-range interactions between promoters and enhancers during V(D)J assembly and class switch recombination (CSR) in the immunoglobulin heavy chain (IgH) locus. This approach led to the notion that CSR is regulated through competition of germ-line (GL) promoters for activities displayed by the 3' regulatory region (3'RR). This polarized long-range effect of the 3'RR is disturbed upon insertion of NeoR gene in the IgH constant (C(H)) region, where only GL transcription derived from upstream GL promoters is impaired. In the context of V(D)J recombination, replacement of Emu enhancer or Emu core enhancer (cEmu) by NeoR gene fully blocked V(D)J recombination and mu0 GL transcription which originates 5' of DQ52 and severely diminished Imu GL transcription derived from Emu/Imu promoter, suggesting a critical role for cEmu in the regulation of V(D)J recombination and of mu0 and Imu expression. Here we focus on the effect of NeoR gene on mu0 and Imu GL transcription in a mouse line in which the Imu-Cmu intron was replaced by a NeoR gene in the sense-orientation. B cell development was characterized by a marked but incomplete block at the pro-B cell stage. However, V(D)J recombination was unaffected in sorted pro-B and pre-B cells excluding an interference with the accessibility control function of Emu. mu0 GL transcription initiation was relatively normal but the maturation step seemed to be affected most likely through premature termination at NeoR polyadenylation sites. In contrast, Imu transcription initiation was impaired suggesting an interference of NeoR gene with the IgH enhancers that control Imu expression. Surprisingly, in stark contrast with the NeoR effect in the C(H) region, LPS-induced NeoR expression restored Imu transcript levels to normal. The data suggest that Emu enhancer may be the master control element that counteracts the down-regulatory "Neo effect" on Imu expression upon LPS

  19. IMU navigation performance evaluation method based on signal grafting technology%基于信号嫁接技术的IMU导航性能评估方法

    Institute of Scientific and Technical Information of China (English)

    高琳; 班亚龙; 牛小骥

    2015-01-01

    为了探究新型惯性测量单元( IMU)的导航定位精度以便选用,需要对其进行方便有效和低成本的测试评估。对一种新颖的基于信号嫁接技术的IMU导航性能评估方法进行了验证和分析。以三种中低精度IMU为样本,将该方法的评估结果与该IMU的现场测试结果对比,从而对该方法的评估效果进行验证。结果表明:相对于IMU的仿真评估,使用信号嫁接技术合成出的IMU数据在导航性能上与现场测试结果有更高的一致性,更为有效和可信。该方法相比于权威的现场测试评估具有成本低、效率高的独特优势,在中低精度惯性器件性能评估上具有很高的应用价值。%In order to evaluate navigation performance of inertial measurement unit( IMU),convenient,efficient and low-cost evaluation methods are needed. A new method based on signal grafting is verified and analyzed,to evaluate the navigation performance of IMU. Three kinds of medium and low precision IMUs are used as samples, to check the evaluation effectiveness of the proposed method,the evaluation results using this method are compared with their actual road test results. Experimental results show that the navigation performances of the grafted IMU data matched much better with that of the real IMU data compared with the simulation IMU data. The proposed signal grafting method is not only reliable and feasible,but also low-cost and efficient,therefore,it has high application value in IMU performance evaluation of medium and low precision.

  20. A New Filtering and Smoothing Algorithm for Railway Track Surveying Based on Landmark and IMU/Odometer.

    Science.gov (United States)

    Jiang, Qingan; Wu, Wenqi; Jiang, Mingming; Li, Yun

    2017-06-19

    High-accuracy railway track surveying is essential for railway construction and maintenance. The traditional approaches based on total station equipment are not efficient enough since high precision surveying frequently needs static measurements. This paper proposes a new filtering and smoothing algorithm based on the IMU/odometer and landmarks integration for the railway track surveying. In order to overcome the difficulty of estimating too many error parameters with too few landmark observations, a new model with completely observable error states is established by combining error terms of the system. Based on covariance analysis, the analytical relationship between the railway track surveying accuracy requirements and equivalent gyro drifts including bias instability and random walk noise are established. Experiment results show that the accuracy of the new filtering and smoothing algorithm for railway track surveying can reach 1 mm (1σ) when using a Ring Laser Gyroscope (RLG)-based Inertial Measurement Unit (IMU) with gyro bias instability of 0.03°/h and random walk noise of 0.005 °h while control points of the track control network (CPIII) position observations are provided by the optical total station in about every 60 m interval. The proposed approach can satisfy at the same time the demands of high accuracy and work efficiency for railway track surveying.

  1. A New Filtering and Smoothing Algorithm for Railway Track Surveying Based on Landmark and IMU/Odometer

    Directory of Open Access Journals (Sweden)

    Qingan Jiang

    2017-06-01

    Full Text Available High-accuracy railway track surveying is essential for railway construction and maintenance. The traditional approaches based on total station equipment are not efficient enough since high precision surveying frequently needs static measurements. This paper proposes a new filtering and smoothing algorithm based on the IMU/odometer and landmarks integration for the railway track surveying. In order to overcome the difficulty of estimating too many error parameters with too few landmark observations, a new model with completely observable error states is established by combining error terms of the system. Based on covariance analysis, the analytical relationship between the railway track surveying accuracy requirements and equivalent gyro drifts including bias instability and random walk noise are established. Experiment results show that the accuracy of the new filtering and smoothing algorithm for railway track surveying can reach 1 mm (1σ when using a Ring Laser Gyroscope (RLG-based Inertial Measurement Unit (IMU with gyro bias instability of 0.03°/h and random walk noise of 0.005 °h while control points of the track control network (CPIII position observations are provided by the optical total station in about every 60 m interval. The proposed approach can satisfy at the same time the demands of high accuracy and work efficiency for railway track surveying.

  2. Accuracy Analysis of IMU/DGPS-supported Aerial Triangulation%IMU/DGPS辅助空中三角测量精度分析

    Institute of Scientific and Technical Information of China (English)

    王铁军; 郑福海; 王俊杰

    2009-01-01

    GPS和IMU技术近年来取得了长足的进步和广泛的应用,两者的组合应用为航空摄影测量无需地面控制而直接定向恢复立体模型提供了可能.本文介绍了GPS像主点辅助空三和IMU/DGPS辅助空三,讨论了IMU/DGPS集成系统在航空摄影测量中的几种应用方式,重点分析了有无地面控制条件下IMU/DGPS辅助空三的精度情况.

  3. Principle and application of IMU/DGPS-based photogrammetry%IMU/DGPS辅助航空摄影测量综述

    Institute of Scientific and Technical Information of China (English)

    李学友

    2005-01-01

    IMU/DGPS辅助航空摄影测量是目前国际上新兴技术,能实现直接获取航摄仪曝光时刻外方位元素数据,使航空摄影测量作业可大量减少或完全免除地面控制点,甚至无需空中三角测量即可测图,从而大大缩短作业周期、提高生产效率、降低成本.本文主要将对IMU/DGPS辅助航空摄影测量的原理、概念、技术流程进行阐述,并简要介绍IMU/DGPS辅助航空摄影测量技术目前在国内的应用进展情况.

  4. Multiple IMU system test plan, volume 4. [subroutines for space shuttle requirements

    Science.gov (United States)

    Landey, M.; Vincent, K. T., Jr.; Whittredge, R. S.

    1974-01-01

    Operating procedures for this redundant system are described. A test plan is developed with two objectives. First, performance of the hardware and software delivered is demonstrated. Second, applicability of multiple IMU systems to the space shuttle mission is shown through detailed experiments with FDI algorithms and other multiple IMU software: gyrocompassing, calibration, and navigation. Gimbal flip is examined in light of its possible detrimental effects on FDI and navigation. For Vol. 3, see N74-10296.

  5. VirtuoZo AAT做IMU/DGPS空三应用分析

    Institute of Scientific and Technical Information of China (English)

    陶毅

    2016-01-01

    IMU/DGPS辅助航空摄影测量是目前国际上新兴技术,能实现直接获取航摄仪曝光时刻外方位元素数据。本文结合实例对适普软件在做IMU/DGPS空三时进行了应用分析。

  6. Validation of distal limb mounted inertial-measurement-unit sensors for stride detection in Warmblood horses at walk and trot

    NARCIS (Netherlands)

    Bragança, F M; Bosch, S; Voskamp, J P; Marin-Perianu, M; Van der Zwaag, B J; Vernooij, J C M; van Weeren, P R; Back, W

    2016-01-01

    BACKGROUND: Inertial-measurement-unit (IMU)-sensor-based techniques are becoming more popular in horses as a tool for objective locomotor assessment. OBJECTIVES: To describe, evaluate and validate a method of stride detection and quantification at walk and trot using distal limb mounted IMU-sensors.

  7. Validation of distal limb mounted inertial measurement unit sensors for stride detection in Warmblood horses at walk and trot

    NARCIS (Netherlands)

    Braganca, F.M.; Bosch, Stephan; Voskamp, J.P.; Marin-Perianu, M.; Zwaag, van der B.J.; Vernooij, J.C.; Weeren, van P.R.; Back, W.

    2016-01-01

    Background: Inertial measurement unit (IMU) sensor-based techniques are becoming more popular in horses as a tool for objective locomotor assessment. Objectives: To describe, evaluate and validate a method of stride detection and quantification at walk and trot using distal limb mounted IMU sensors

  8. Numerical study of an error model for a strap-down INS

    Science.gov (United States)

    Grigorie, T. L.; Sandu, D. G.; Corcau, C. L.

    2016-10-01

    The paper presents a numerical study related to a mathematical error model developed for a strap-down inertial navigation system. The study aims to validate the error model by using some Matlab/Simulink software models implementing the inertial navigator and the error model mathematics. To generate the inputs in the evaluation Matlab/Simulink software some inertial sensors software models are used. The sensors models were developed based on the IEEE equivalent models for the inertial sensorsand on the analysis of the data sheets related to real inertial sensors. In the paper are successively exposed the inertial navigation equations (attitude, position and speed), the mathematics of the inertial navigator error model, the software implementations and the numerical evaluation results.

  9. A fast and accurate initial alignment method for strapdown inertial navigation system on stationary base

    Institute of Scientific and Technical Information of China (English)

    Xinlong WANG; Gongxun SHEN

    2005-01-01

    In this work,a fast and accurate stationary alignment method for strapdown inertial navigation system (SINS) is proposed.It has been demonstrated that the stationary alignment of SINS can be improved by employing the multiposition technique,but the alignment time of the azimuth error is relatively longer.Over here,the two-position alignment principle is presented.On the basis of this SINS error model,a fast estimation algorithm of the azimuth error for the initial alignment of SINS on stationary base is derived fully from the horizontal velocity outputs and the output rates,and the novel azimuth error estimation algorithm is used for the two-position alignment.Consequently,the speed and accuracy of the SINS's initial alignment is enhanced greatly.The computer simulation results illustrate the efficiency of this alignment method.

  10. Strapdown inertial systems applications for tactical missiles (stand-off missiles)

    Science.gov (United States)

    Puech

    1986-06-01

    Strapdown Inertial Systems (SDIS) are particularly well suited for tactical standoff missile applications. This certainty was made clear by several years of theoretical design work and trials. Initial theoretical work made wide use of parameters giving detailed definition of missile trajectories and motions as obtained from measurements made on weapon systems then in development or production. Sensors (principally gyroscopes) were laboratory tested. These preliminary design efforts led to selection of various technologies such as the laser gyro and the mechanical gyro, each being adapted to the weapon system in question. Share-out of functions between various equipment items was defined. Comparison of the advantages and disadvantages of these technologies shows that today the laser gyro is principally retained for high and medium range levels of precision, with the mechanical (spin-stabilized) gyro serving in the medium and low precision range. Since requirements are ever increasing in the fields of dynamic performance and robustness, it is here that most progress is expected.

  11. Noncommutativity Error Analysis of Strapdown Inertial Navigation System under the Vibration in UAVs

    Directory of Open Access Journals (Sweden)

    Jizhou Lai

    2012-10-01

    Full Text Available Noncommutativity error of a strapdown inertial navigation system (SINS in an unmanned aerial vehicle’s (UAV vibration environment is analysed. The traditional analysis of noncommutativity errors is based on a coning motion model, which is inconsistent with a UAV’s vibration environment. In this paper the UAV’s vibration form is discussed and is modelled as a sinusoidal angular vibration and a random angular vibration. Then, SINS motion models under these two forms of vibration are built up and the formulas for the noncommutativity errors are derived separately. In addition, the effect of a multi‐sample algorithm is explored, which is an effective method for compensating for noncommutativity errors in cases of coning motion. Finally, the UAV’s vibration environment is simulated and it is indicated that the simulation results of the SINS’s noncommutativity errors are consistent with theoretical analysis.

  12. Optimized Design of the SGA-WZ Strapdown Airborne Gravimeter Temperature Control System

    Directory of Open Access Journals (Sweden)

    Juliang Cao

    2015-12-01

    Full Text Available The temperature control system is one of the most important subsystems of the strapdown airborne gravimeter. Because the quartz flexible accelerometer based on springy support technology is the core sensor in the strapdown airborne gravimeter and the magnet steel in the electromagnetic force equilibrium circuits of the quartz flexible accelerometer is greatly affected by temperature, in order to guarantee the temperature control precision and minimize the effect of temperature on the gravimeter, the SGA-WZ temperature control system adopts a three-level control method. Based on the design experience of the SGA-WZ-01, the SGA-WZ-02 temperature control system came out with a further optimized design. In 1st level temperature control, thermoelectric cooler is used to conquer temperature change caused by hot weather. The experiments show that the optimized stability of 1st level temperature control is about 0.1 °C and the max cool down capability is about 10 °C. The temperature field is analyzed in the 2nd and 3rd level temperature control using the finite element analysis software ANSYS. The 2nd and 3rd level temperature control optimization scheme is based on the foundation of heat analysis. The experimental results show that static accuracy of SGA-WZ-02 reaches 0.21 mGal/24 h, with internal accuracy being 0.743 mGal/4.8 km and external accuracy being 0.37 mGal/4.8 km compared with the result of the GT-2A, whose internal precision is superior to 1 mGal/4.8 km and all of them are better than those in SGA-WZ-01.

  13. Essential roles for imuA′- and imuB-encoded accessory factors in DnaE2-dependent mutagenesis in Mycobacterium tuberculosis

    OpenAIRE

    2010-01-01

    In Mycobacterium tuberculosis (Mtb), damage-induced mutagenesis is dependent on the C-family DNA polymerase, DnaE2. Included with dnaE2 in the Mtb SOS regulon is a putative operon comprising Rv3395c, which encodes a protein of unknown function restricted primarily to actinomycetes, and Rv3394c, which is predicted to encode a Y-family DNA polymerase. These genes were previously identified as components of an imuA-imuB-dnaE2–type mutagenic cassette widespread among bacterial genomes. Here, we c...

  14. A novel vehicle stationary detection utilizing map matching and IMU sensors.

    Science.gov (United States)

    Amin, Md Syedul; Reaz, Mamun Bin Ibne; Nasir, Salwa Sheikh; Bhuiyan, Mohammad Arif Sobhan; Ali, Mohd Alauddin Mohd

    2014-01-01

    Precise navigation is a vital need for many modern vehicular applications. The global positioning system (GPS) cannot provide continuous navigation information in urban areas. The widely used inertial navigation system (INS) can provide full vehicle state at high rates. However, the accuracy diverges quickly in low cost microelectromechanical systems (MEMS) based INS due to bias, drift, noise, and other errors. These errors can be corrected in a stationary state. But detecting stationary state is a challenging task. A novel stationary state detection technique from the variation of acceleration, heading, and pitch and roll of an attitude heading reference system (AHRS) built from the inertial measurement unit (IMU) sensors is proposed. Besides, the map matching (MM) algorithm detects the intersections where the vehicle is likely to stop. Combining these two results, the stationary state is detected with a smaller timing window of 3 s. A longer timing window of 5 s is used when the stationary state is detected only from the AHRS. The experimental results show that the stationary state is correctly identified and the position error is reduced to 90% and outperforms previously reported work. The proposed algorithm would help to reduce INS errors and enhance the performance of the navigation system.

  15. On the Orientation Error of IMU: Investigating Static and Dynamic Accuracy Targeting Human Motion.

    Science.gov (United States)

    Ricci, Luca; Taffoni, Fabrizio; Formica, Domenico

    2016-01-01

    The accuracy in orientation tracking attainable by using inertial measurement units (IMU) when measuring human motion is still an open issue. This study presents a systematic quantification of the accuracy under static conditions and typical human dynamics, simulated by means of a robotic arm. Two sensor fusion algorithms, selected from the classes of the stochastic and complementary methods, are considered. The proposed protocol implements controlled and repeatable experimental conditions and validates accuracy for an extensive set of dynamic movements, that differ in frequency and amplitude of the movement. We found that dynamic performance of the tracking is only slightly dependent on the sensor fusion algorithm. Instead, it is dependent on the amplitude and frequency of the movement and a major contribution to the error derives from the orientation of the rotation axis w.r.t. the gravity vector. Absolute and relative errors upper bounds are found respectively in the range [0.7° ÷ 8.2°] and [1.0° ÷ 10.3°]. Alongside dynamic, static accuracy is thoroughly investigated, also with an emphasis on convergence behavior of the different algorithms. Reported results emphasize critical issues associated with the use of this technology and provide a baseline level of performance for the human motion related application.

  16. A Vondrak low pass filter for IMU sensor initial alignment on a disturbed base.

    Science.gov (United States)

    Li, Zengke; Wang, Jian; Gao, Jingxiang; Li, Binghao; Zhou, Feng

    2014-12-10

    The initial alignment of the Inertial Measurement Unit (IMU) is an important process of INS to determine the coordinate transformation matrix which is used in the integration of Global Positioning Systems (GPS) with Inertial Navigation Systems (INS). In this paper a novel alignment method for a disturbed base, such as a vehicle disturbed by wind outdoors, implemented with the aid of a Vondrak low pass filter, is proposed. The basic principle of initial alignment including coarse alignment and fine alignment is introduced first. The spectral analysis is processed to compare the differences between the characteristic error of INS force observation on a stationary base and on disturbed bases. In order to reduce the high frequency noise in the force observation more accurately and more easily, a Vondrak low pass filter is constructed based on the spectral analysis result. The genetic algorithms method is introduced to choose the smoothing factor in the Vondrak filter and the corresponding objective condition is built. The architecture of the proposed alignment method with the Vondrak low pass filter is shown. Furthermore, simulated experiments and actual experiments were performed to validate the new algorithm. The results indicate that, compared with the conventional alignment method, the Vondrak filter could eliminate the high frequency noise in the force observation and the proposed alignment method could improve the attitude accuracy. At the same time, only one parameter needs to be set, which makes the proposed method easier to implement than other low-pass filter methods.

  17. Unsupervised segmentation of heel-strike IMU data using rapid cluster estimation of wavelet features.

    Science.gov (United States)

    Yuwono, Mitchell; Su, Steven W; Moulton, Bruce D; Nguyen, Hung T

    2013-01-01

    When undertaking gait-analysis, one of the most important factors to consider is heel-strike (HS). Signals from a waist worn Inertial Measurement Unit (IMU) provides sufficient accelerometric and gyroscopic information for estimating gait parameter and identifying HS events. In this paper we propose a novel adaptive, unsupervised, and parameter-free identification method for detection of HS events during gait episodes. Our proposed method allows the device to learn and adapt to the profile of the user without the need of supervision. The algorithm is completely parameter-free and requires no prior fine tuning. Autocorrelation features (ACF) of both antero-posterior acceleration (aAP) and medio-lateral acceleration (aML) are used to determine cadence episodes. The Discrete Wavelet Transform (DWT) features of signal peaks during cadence are extracted and clustered using Swarm Rapid Centroid Estimation (Swarm RCE). Left HS (LHS), Right HS (RHS), and movement artifacts are clustered based on intra-cluster correlation. Initial pilot testing of the system on 8 subjects show promising results up to 84.3%±9.2% and 86.7%±6.9% average accuracy with 86.8%±9.2% and 88.9%±7.1% average precision for the segmentation of LHS and RHS respectively.

  18. A Vondrak Low Pass Filter for IMU Sensor Initial Alignment on a Disturbed Base

    Directory of Open Access Journals (Sweden)

    Zengke Li

    2014-12-01

    Full Text Available The initial alignment of the Inertial Measurement Unit (IMU is an important process of INS to determine the coordinate transformation matrix which is used in the integration of Global Positioning Systems (GPS with Inertial Navigation Systems (INS. In this paper a novel alignment method for a disturbed base, such as a vehicle disturbed by wind outdoors, implemented with the aid of a Vondrak low pass filter, is proposed. The basic principle of initial alignment including coarse alignment and fine alignment is introduced first. The spectral analysis is processed to compare the differences between the characteristic error of INS force observation on a stationary base and on disturbed bases. In order to reduce the high frequency noise in the force observation more accurately and more easily, a Vondrak low pass filter is constructed based on the spectral analysis result. The genetic algorithms method is introduced to choose the smoothing factor in the Vondrak filter and the corresponding objective condition is built. The architecture of the proposed alignment method with the Vondrak low pass filter is shown. Furthermore, simulated experiments and actual experiments were performed to validate the new algorithm. The results indicate that, compared with the conventional alignment method, the Vondrak filter could eliminate the high frequency noise in the force observation and the proposed alignment method could improve the attitude accuracy. At the same time, only one parameter needs to be set, which makes the proposed method easier to implement than other low-pass filter methods.

  19. An IMU-to-Body Alignment Method Applied to Human Gait Analysis

    Directory of Open Access Journals (Sweden)

    Laura Susana Vargas-Valencia

    2016-12-01

    Full Text Available This paper presents a novel calibration procedure as a simple, yet powerful, method to place and align inertial sensors with body segments. The calibration can be easily replicated without the need of any additional tools. The proposed method is validated in three different applications: a computer mathematical simulation; a simplified joint composed of two semi-spheres interconnected by a universal goniometer; and a real gait test with five able-bodied subjects. Simulation results demonstrate that, after the calibration method is applied, the joint angles are correctly measured independently of previous sensor placement on the joint, thus validating the proposed procedure. In the cases of a simplified joint and a real gait test with human volunteers, the method also performs correctly, although secondary plane errors appear when compared with the simulation results. We believe that such errors are caused by limitations of the current inertial measurement unit (IMU technology and fusion algorithms. In conclusion, the presented calibration procedure is an interesting option to solve the alignment problem when using IMUs for gait analysis.

  20. On the Orientation Error of IMU: Investigating Static and Dynamic Accuracy Targeting Human Motion

    Science.gov (United States)

    Ricci, Luca; Taffoni, Fabrizio

    2016-01-01

    The accuracy in orientation tracking attainable by using inertial measurement units (IMU) when measuring human motion is still an open issue. This study presents a systematic quantification of the accuracy under static conditions and typical human dynamics, simulated by means of a robotic arm. Two sensor fusion algorithms, selected from the classes of the stochastic and complementary methods, are considered. The proposed protocol implements controlled and repeatable experimental conditions and validates accuracy for an extensive set of dynamic movements, that differ in frequency and amplitude of the movement. We found that dynamic performance of the tracking is only slightly dependent on the sensor fusion algorithm. Instead, it is dependent on the amplitude and frequency of the movement and a major contribution to the error derives from the orientation of the rotation axis w.r.t. the gravity vector. Absolute and relative errors upper bounds are found respectively in the range [0.7° ÷ 8.2°] and [1.0° ÷ 10.3°]. Alongside dynamic, static accuracy is thoroughly investigated, also with an emphasis on convergence behavior of the different algorithms. Reported results emphasize critical issues associated with the use of this technology and provide a baseline level of performance for the human motion related application. PMID:27612100

  1. Indoor Pedestrian Navigation Using Foot-Mounted IMU and Portable Ultrasound Range Sensors

    Directory of Open Access Journals (Sweden)

    Stéphane Côté

    2011-08-01

    Full Text Available Many solutions have been proposed for indoor pedestrian navigation. Some rely on pre-installed sensor networks, which offer good accuracy but are limited to areas that have been prepared for that purpose, thus requiring an expensive and possibly time-consuming process. Such methods are therefore inappropriate for navigation in emergency situations since the power supply may be disturbed. Other types of solutions track the user without requiring a prepared environment. However, they may have low accuracy. Offline tracking has been proposed to increase accuracy, however this prevents users from knowing their position in real time. This paper describes a real time indoor navigation system that does not require prepared building environments and provides tracking accuracy superior to previously described tracking methods. The system uses a combination of four techniques: foot-mounted IMU (Inertial Motion Unit, ultrasonic ranging, particle filtering and model-based navigation. The very purpose of the project is to combine these four well-known techniques in a novel way to provide better indoor tracking results for pedestrians.

  2. Pedestrian Stride Length Estimation from IMU Measurements and ANN Based Algorithm

    Directory of Open Access Journals (Sweden)

    Haifeng Xing

    2017-01-01

    Full Text Available Pedestrian dead reckoning (PDR can be used for continuous position estimation when satellite or other radio signals are not available, and the accuracy of the stride length measurement is important. Current stride length estimation algorithms, including linear and nonlinear models, consider a few variable factors, and some rely on high precision and high cost equipment. This paper puts forward a stride length estimation algorithm based on a back propagation artificial neural network (BP-ANN, using a consumer-grade inertial measurement unit (IMU; it then discusses various factors in the algorithm. The experimental results indicate that the error of the proposed algorithm in estimating the stride length is approximately 2%, which is smaller than that of the frequency and nonlinear models. Compared with the latter two models, the proposed algorithm does not need to determine individual parameters in advance if the trained neural net is effective. It can, thus, be concluded that this algorithm shows superior performance in estimating pedestrian stride length.

  3. IMU Application in Measurement of Vehicle Position and Orientation for Controlling a Pan-Tilt Mechanism

    Directory of Open Access Journals (Sweden)

    Hendri Maja Saputra

    2013-07-01

    Full Text Available This paper describes a modeling and designing of inertial sensor using Inertial Measurement Unit (IMU to measure the position and orientation of a vehicle motion. Sensor modeling is used to derive the vehicle attitude models where the sensor is attached while the sensor design is used to obtain the data as the input to control the angles of a pan-tilt mechanism with 2 degrees of freedom. Inertial sensor Phidget Spatial 3/3/3, which is a combination of 3-axis gyroscope, 3-axis accelerometer and 3-axis magnetometer, is used as the research object. Software for reading the sensor was made by using Matlab™. The result shows that the software can be applied to the sensor in the real-time reading process. The sensor readings should consider several things i.e. (a sampling time should not be less than 32 ms and (b deviation ratio between measurement noise (r and process noise (q for the parameters of Kalman filter is 1:5 (i.e. r = 0.08 and q = 0.4.

  4. Coupled GPS/MEMS IMU Attitude Determination of Small UAVs with COTS

    Directory of Open Access Journals (Sweden)

    Michael Strohmeier

    2017-02-01

    Full Text Available This paper proposes an attitude determination system for small Unmanned Aerial Vehicles (UAV with a weight limit of 5 kg and a small footprint of 0.5m x 0.5 m. The system is realized by coupling single-frequency Global Positioning System (GPS code and carrier-phase measurements with the data acquired from a Micro-Electro-Mechanical System (MEMS Inertial Measurement Unit (IMU using consumer-grade Components-Off-The-Shelf (COTS only. The sensor fusion is accomplished using two Extended Kalman Filters (EKF that are coupled by exchanging information about the currently estimated baseline. With a baseline of 48 cm, the static heading accuracy of the proposed system is comparable to the one of a commercial single-frequency GPS heading system with an accuracy of approximately 0.25°/m. Flight testing shows that the proposed system is able to obtain a reliable and stable GPS heading estimation without an aiding magnetometer.

  5. Practical method for estimating road curvatures using onboard GPS and IMU equipment

    Science.gov (United States)

    Zamfir, S.; Drosescu, R.; Gaiginschi, R.

    2016-08-01

    This paper describes an experimental method to determine with high accuracy the curvature of a road segment, the turning radius of a car, and the discomfort level perceived by the passengers in the vehicle cabin when passing through a curve. For these experiments we used professional equipment provided with two GPS active antennas with 13 dB gain featuring non-contact 100 Hz speed and distance measurement, and a ten degree Inertial Measurement Unit (IMU) with dynamic orientation outputs. The same experimental measurements also usedthe low cost GPS equipment available on smartphones, domestic vehicle GPS devices, as well as an Arduino GPS shield in order to compare the results generated by professional equipment. The purpose of these experiments was also to establish if certain road curve sections were correctly executed in order to ensure the safety and comfort of passengers. Another use of the proposed method relates to the road accident reconstruction field, providing experts and forensics with an accurate method of measuring the roadway curvature at accident scenes or traffic events. The research and equipment described in this paper have been acquired and developed under a PhD studyand a European funded project won and elaborated by the authors.

  6. Indoor pedestrian navigation using foot-mounted IMU and portable ultrasound range sensors.

    Science.gov (United States)

    Girard, Gabriel; Côté, Stéphane; Zlatanova, Sisi; Barette, Yannick; St-Pierre, Johanne; van Oosterom, Peter

    2011-01-01

    Many solutions have been proposed for indoor pedestrian navigation. Some rely on pre-installed sensor networks, which offer good accuracy but are limited to areas that have been prepared for that purpose, thus requiring an expensive and possibly time-consuming process. Such methods are therefore inappropriate for navigation in emergency situations since the power supply may be disturbed. Other types of solutions track the user without requiring a prepared environment. However, they may have low accuracy. Offline tracking has been proposed to increase accuracy, however this prevents users from knowing their position in real time. This paper describes a real time indoor navigation system that does not require prepared building environments and provides tracking accuracy superior to previously described tracking methods. The system uses a combination of four techniques: foot-mounted IMU (Inertial Motion Unit), ultrasonic ranging, particle filtering and model-based navigation. The very purpose of the project is to combine these four well-known techniques in a novel way to provide better indoor tracking results for pedestrians.

  7. An enhanced inertial navigation system based on a low-cost IMU and laser scanner

    Science.gov (United States)

    Kim, Hyung-Soon; Baeg, Seung-Ho; Yang, Kwang-Woong; Cho, Kuk; Park, Sangdeok

    2012-06-01

    This paper describes an enhanced fusion method for an Inertial Navigation System (INS) based on a 3-axis accelerometer sensor, a 3-axis gyroscope sensor and a laser scanner. In GPS-denied environments, indoor or dense forests, a pure INS odometry is available for estimating the trajectory of a human or robot. However it has a critical implementation problem: a drift error of velocity, position and heading angles. Commonly the problem can be solved by fusing visual landmarks, a magnetometer or radio beacons. These methods are not robust in diverse environments: darkness, fog or sunlight, an unstable magnetic field and an environmental obstacle. We propose to overcome the drift problem using an Iterative Closest Point (ICP) scan matching algorithm with a laser scanner. This system consists of three parts. The first is the INS. It estimates attitude, velocity, position based on a 6-axis Inertial Measurement Unit (IMU) with both 'Heuristic Reduction of Gyro Drift' (HRGD) and 'Heuristic Reduction of Velocity Drift' (HRVD) methods. A frame-to-frame ICP matching algorithm for estimating position and attitude by laser scan data is the second. The third is an extended kalman filter method for multi-sensor data fusing: INS and Laser Range Finder (LRF). The proposed method is simple and robust in diverse environments, so we could reduce the drift error efficiently. We confirm the result comparing an odometry of the experimental result with ICP and LRF aided-INS in a long corridor.

  8. 基于分度台转位装置的惯性测量单元智能检测%Intelligent Detection for IMU Based on Dividing Table Indexing Device

    Institute of Scientific and Technical Information of China (English)

    王斌; 张林; 邓军; 熊耀臣; 吕明

    2015-01-01

    针对惯性测量单元(IMU)批量检测效率低、人工劳动量大的现状,设计开发出一种基于分度台转位装置的IMU智能检测系统。其采用高精度分度台转位装置为IMU提供基准角度位置,利用工控机控制分度台转位装置、程控直流电源和IMU协调有序工作,通过上位机软件智能控制程控直流电源向IMU供电,以及自动发送、采集、分析和处理检测数据,实现对IMU的智能、高效、精确检测。实验结果表明,该系统可同时自动检测4套IMU 的参数指标,并自动计算、显示和保存检测数据,且检测精度、效率和智能化程度高,人工劳动量小,性价比高,此外,软件界面上所有功能均可手动触摸操控,操作十分便捷。%According to the current situation that inertial measuring unit(IMU) is detected with low measurement efficiency and large amount of labour, this article designs and develops an IMU intelligent measurement system based on dividing table indexing device. This system makes use of dividing table indexing device to provide reference angle positions, takes advantage of industrial computer to control dividing table indexing device, programmable DC power and IMU to work orderly and harmoniously. Besides, host-computer software can control the programmable DC power to supply electricity for IMU, and automatically send, collect, analyze and process measurement data to detect IMU intelligently, efficiently and accurately. The experiment result shows that 4 IMUs can be detected automatically at the same time, all detection data can be computed, displayed and saved. Moreover, this system has the features of high detection precision, more efficient, high level of intelligence, small amount of labor, and high performance-cost ratio. In addition, all functions in software interface can be operated through manual touch, which makes it convenient to operate.

  9. IMU/DGPS辅助航空摄影测量综述

    Institute of Scientific and Technical Information of China (English)

    李学友

    2005-01-01

    IMU/DGPS辅助航空摄影测量是目前国际上新兴技术,能实现直接获取航摄仪曝光时刻外方位元素数据,使航空摄影测量作业可大量减少或完全免除地面控制点,甚至无需空中三角测量即可测图,从而大大缩短作业周期、提高生产效率、降低成本.本文主要将对IMU/DGPS辅助航空摄影测量的原理、概念、技术流程进行阐述,并简要介绍IMU/DGPS辅助航空摄影测量技术目前在国内的应用进展情况.

  10. SWDC结合IMU/DGPS航测的可行性研究

    Institute of Scientific and Technical Information of China (English)

    李新泉

    2012-01-01

    主要介绍了在现有情况下SWDC结合IMU/DGPS的研究方法和在不同分辨率的情况下进行航飞任务的情况,探讨了在SWDC上结合IMU/DGPS进行航测任务的可行性以及采集数据结果的可靠性。通过不同地域的3个测区任务的开展表明:在SWDC上结合IMU/DGPS的技术是可靠的,进行航测工作时航测成果完全满足成图精度要求,可以取代常规空三作业方式。

  11. Integration of a Strapdown Gravimeter System in AN Autonomous Underwater Vehicle

    Science.gov (United States)

    Roussel, C.; Verdun, J.; Cali, J.; Maia, M.; d'EU, J. F.

    2015-04-01

    We present a new mobile instrument for measuring dynamically the gravity vector and its gradients in underwater environment, named GRAVIMOB. Our instrument is a strapdown sensor, consisted of electrostatic accelerometers installed in a waterproof sphere. It is designed to be embedded in an Autonomous Underwater Vehicle (AUV). Since the positioning of an AUV is approximate in underwater environment, the key issue raised here is to estimate the uncertainty in the gravity field resulting from the use of such position data. This paper focuses on the assessment of the system performances. The latter have been studied by simulation with reference data calculated from actual submarine geological structures, on which different noise models have been added. Results show that spatial evolutions of the gravity field and statistical properties of stochastic processes affecting the measurements have to be considered carefully in order the minimize the error. The Unscented Kalman Filter (UKF) has been favored to the Extended Kalman Filter (EKF) by its ease of implementation and its better robustness to non-linearities.

  12. Technology research for strapdown inertial experiment and digital flight control and guidance

    Science.gov (United States)

    Carestia, R. A.; Cottrell, D. E.

    1985-01-01

    A helicopter flight-test program to evaluate the performance of Honeywell's Tetrad - a strapdown, laser gyro, inertial navitation system is discussed. The results of 34 flights showed a mean final navigational velocity error of 5.06 knots, with a standard deviation of 3.84 knots; a corresponding mean final position error of 2.66 n.mi., with a standard deviation of 1.48 n.m.; and a modeled mean-position-error growth rate for the 34 tests of 1.96 knots, with a standard deviation of 1.09 knots. Tetrad's four-ring laser gyros provided reliable and accurate angular rate sensing during the test program and on sensor failures were detected during the evaluation. Criteria suitable for investigating cockpit systems in rotorcraft were developed. This criteria led to the development of two basic simulators. The first was a standard simulator which could be used to obtain baseline information for studying pilot workload and interactions. The second was an advanced simulator which integrated the RODAAS developed by Honeywell into this simulator. The second area also included surveying the aerospace industry to determine the level of use and impact of microcomputers and related components on avionics systems.

  13. Optical flow based guidance system design for semi-strapdown image homing guided missiles

    Directory of Open Access Journals (Sweden)

    Huang Lan

    2016-10-01

    Full Text Available This paper focuses mainly on semi-strapdown image homing guided (SSIHG system design based on optical flow for a six-degree-of-freedom (6-DOF axial-symmetric skid-to-turn missile. Three optical flow algorithms suitable for large displacements are introduced and compared. The influence of different displacements on computational accuracy of the three algorithms is analyzed statistically. The total optical flow of the SSIHG missile is obtained using the Scale Invariant Feature Transform (SIFT algorithm, which is the best among the three for large displacements. After removing the rotational optical flow caused by rotation of the gimbal and missile body from the total optical flow, the remaining translational optical flow is smoothed via Kalman filtering. The circular navigation guidance (CNG law with impact angle constraint is then obtained utilizing the smoothed translational optical flow and position of the target image. Simulations are carried out under both disturbed and undisturbed conditions, and results indicate the proposed guidance strategy for SSIHG missiles can result in a precise target hit with a desired impact angle without the need for the time-to-go parameter.

  14. Error Analysis and Reduction for Shearer Positioning using the Strapdown Inertial Navigation System

    Directory of Open Access Journals (Sweden)

    Chengming Luo

    2012-09-01

    Full Text Available Shearer dynamic positioning is a key factor for coal mine equipment automation, and it is feasible to shearer positioning using the strapdown inertial navigation system(SINS. Yet, it is very difficult to guarantee positioning accuracy by error influence. This paper provided a method for shearer positioning error analysis. Firstly, we built the shearer state equation and put forward a method called quaternion method rule. This method can deduce misalignment angle of the shearer Inertial Navigation System. Secondly, we considered the initial alignment error of INS is the main system error, the nonlinear Extended Kalman Filter (EKF is proposed to estimate and adjust the misalignment angles, as well as the shearer velocity. Shearer dynamic positioning accuracy is guaranteed by precise and fast alignment of the INS. Based on the shearer state equation; this paper derived the observation equation. Finally, we simulated the initial alignments process which contains the observation equation and initial condition, and did experiment using ADIS16350. Results show misalignment angles model and EKF is feasible for initial alignments of INS in shearer positioning.

  15. Comparison of strapdown inertial navigation algorithm based on rotation vector and dual quaternion

    Institute of Scientific and Technical Information of China (English)

    Wang Zhenhuan; Chen Xijun; Zeng Qingshuang

    2013-01-01

    For the navigation algorithm of the strapdown inertial navigation system,by comparing to the equations of the dual quaternion and quaternion,the superiority of the attitude algorithm based on dual quaternion over the ones based on rotation vector in accuracy is analyzed in the case of the rotation of navigation frame.By comparing the update algorithm of the gravitational velocity in dual quaternion solution with the compensation algorithm of the harmful acceleration in traditional velocity solution,the accuracy advantage of the gravitational velocity based on dual quaternion is addressed.In view of the idea of the attitude and velocity algorithm based on dual quaternion,an improved navigation algorithm is proposed,which is as much as the rotation vector algorithm in computational complexity.According to this method,the attitude quaternion does not require compensating as the navigation frame rotates.In order to verify the correctness of the theoretical analysis,simulations are carried out utilizing the software,and the simulation results show that the accuracy of the improved algorithm is approximately equal to the dual quaternion algorithm.

  16. Angular Rate Optimal Design for the Rotary Strapdown Inertial Navigation System

    Directory of Open Access Journals (Sweden)

    Fei Yu

    2014-04-01

    Full Text Available Due to the characteristics of high precision for a long duration, the rotary strapdown inertial navigation system (RSINS has been widely used in submarines and surface ships. Nowadays, the core technology, the rotating scheme, has been studied by numerous researchers. It is well known that as one of the key technologies, the rotating angular rate seriously influences the effectiveness of the error modulating. In order to design the optimal rotating angular rate of the RSINS, the relationship between the rotating angular rate and the velocity error of the RSINS was analyzed in detail based on the Laplace transform and the inverse Laplace transform in this paper. The analysis results showed that the velocity error of the RSINS depends on not only the sensor error, but also the rotating angular rate. In order to minimize the velocity error, the rotating angular rate of the RSINS should match the sensor error. One optimal design method for the rotating rate of the RSINS was also proposed in this paper. Simulation and experimental results verified the validity and superiority of this optimal design method for the rotating rate of the RSINS.

  17. Research on identifying the dynamic error model of strapdown gyro on 3-axis turntable

    Institute of Scientific and Technical Information of China (English)

    WANG Hai; REN Shun-qing; WANG Chang-hong

    2005-01-01

    The dynamic errors of gyros are the important error sources of a strapdown inertial navigation system.In order to identify the dynamic error model coefficients accurately, the static erTor model coefficients which lay a foundation for compensating while identifying the dynamic error model are identified in the gravity acceleration fields by using angular position function of the three-axis turntable. The angular acceleration and angular velocity are excited on the input, output and spin axis of the gyros when the outer axis and the middle axis of a threeaxis turntable are in the uniform angular velocity state simultaneously, while the inner axis of the turntable is in different static angular positions. 8 groups of data are sampled when the inner axis is in 8 different angular positions. These data are the function of the middle axis positions and the inner axis positions. For these data, harmonic analysis method is applied two times versus the middle axis positions and inner axis positions respectively so that the dynamic error model coefficients are finally identified through the least square method. In the meantime the optimal angular velocity of the outer axis and the middle axis are selected by computing the determination value of the information matrix.

  18. Application of IMU/ DGPS Supported Aero Photogrammetry in Qinling Mountainous Area%IMU/ DGPS辅助航空摄影测量在秦岭山区的应用探讨

    Institute of Scientific and Technical Information of China (English)

    桑东文; 张骥

    2010-01-01

    通过秦岭摄区的IMU/ DGPS辅助航空摄影测量的生产实践,对IMU/ DGPS辅助航空摄影技术在高山困难区域的应用进行了探讨.结果证明,IMU/ DGPS辅助空三加密成果能满足丘陵地、山地及高山地1:10 000地形图测图的平面和高程精度要求.

  19. IMU/DGPS辅助的大跨度航线区域网平差精度分析%Accuracy Analysis of IMU/DGPS-supported Long Span Flight Course Block Adjustment

    Institute of Scientific and Technical Information of China (English)

    满燕; 罗瞳

    2010-01-01

    试验无控制和稀少控制条件下IMU/DGPS辅助的大跨度航线区域网平差,讨论IMU/DGPS辅助的大跨度航空摄影测量的精度情况;并通过与传统空中三角测量的对比,分析IMU/DGPS辅助的航测技术在节省外业控制方面的优势.

  20. Experiment for Large Area of Forest by IMU/DGPS Supported Aerophotogrammetry%IMU/DGPS辅助航测技术在大面积森林覆盖区域的应用试验

    Institute of Scientific and Technical Information of China (English)

    白志刚

    2010-01-01

    介绍了IMU/DGPS辅助航空摄影测量,并进行了其在大面积森林覆盖区域的空三的试验.结果表明IMU/DGPS辅助航测技术在大面积森林覆盖区域成图生产中,IMU/DGPS辅助空中三角测量方法很有优势,能够满足我国现行航空摄影测量规范对航测生产的精度要求.

  1. Monocular Camera/IMU/GNSS Integration for Ground Vehicle Navigation in Challenging GNSS Environments

    Directory of Open Access Journals (Sweden)

    Dennis Akos

    2012-03-01

    Full Text Available Low-cost MEMS-based IMUs, video cameras and portable GNSS devices are commercially available for automotive applications and some manufacturers have already integrated such facilities into their vehicle systems. GNSS provides positioning, navigation and timing solutions to users worldwide. However, signal attenuation, reflections or blockages may give rise to positioning difficulties. As opposed to GNSS, a generic IMU, which is independent of electromagnetic wave reception, can calculate a high-bandwidth navigation solution, however the output from a self-contained IMU accumulates errors over time. In addition, video cameras also possess great potential as alternate sensors in the navigation community, particularly in challenging GNSS environments and are becoming more common as options in vehicles. Aiming at taking advantage of these existing onboard technologies for ground vehicle navigation in challenging environments, this paper develops an integrated camera/IMU/GNSS system based on the extended Kalman filter (EKF. Our proposed integration architecture is examined using a live dataset collected in an operational traffic environment. The experimental results demonstrate that the proposed integrated system provides accurate estimations and potentially outperforms the tightly coupled GNSS/IMU integration in challenging environments with sparse GNSS observations.

  2. Monocular camera/IMU/GNSS integration for ground vehicle navigation in challenging GNSS environments.

    Science.gov (United States)

    Chu, Tianxing; Guo, Ningyan; Backén, Staffan; Akos, Dennis

    2012-01-01

    Low-cost MEMS-based IMUs, video cameras and portable GNSS devices are commercially available for automotive applications and some manufacturers have already integrated such facilities into their vehicle systems. GNSS provides positioning, navigation and timing solutions to users worldwide. However, signal attenuation, reflections or blockages may give rise to positioning difficulties. As opposed to GNSS, a generic IMU, which is independent of electromagnetic wave reception, can calculate a high-bandwidth navigation solution, however the output from a self-contained IMU accumulates errors over time. In addition, video cameras also possess great potential as alternate sensors in the navigation community, particularly in challenging GNSS environments and are becoming more common as options in vehicles. Aiming at taking advantage of these existing onboard technologies for ground vehicle navigation in challenging environments, this paper develops an integrated camera/IMU/GNSS system based on the extended Kalman filter (EKF). Our proposed integration architecture is examined using a live dataset collected in an operational traffic environment. The experimental results demonstrate that the proposed integrated system provides accurate estimations and potentially outperforms the tightly coupled GNSS/IMU integration in challenging environments with sparse GNSS observations.

  3. Underground mine navigation using an integrated IMU/TOF system with unscented Kalman filter

    CSIR Research Space (South Africa)

    Hlophe, K

    2011-07-01

    Full Text Available GPS. Our research interest is focused on using low-cost off-the-shelf IMU to improve the Active Beacon Positioning System (ABPS) developed here at the CSIR. This paper proposes a novel pose estimator, for underground mines, that fuses together data...

  4. Validity of Ski Skating Center-of-Mass Displacement Measured by a Single Inertial Measurement Unit.

    Science.gov (United States)

    Myklebust, Håvard; Gløersen, Øyvind; Hallén, Jostein

    2015-12-01

    In regard to simplifying motion analysis and estimating center of mass (COM) in ski skating, this study addressed 3 main questions concerning the use of inertial measurement units (IMU): (1) How accurately can a single IMU estimate displacement of os sacrum (S1) on a person during ski skating? (2) Does incorporating gyroscope and accelerometer data increase accuracy and precision? (3) Moreover, how accurately does S1 determine COM displacement? Six world-class skiers roller-ski skated on a treadmill using 2 different subtechniques. An IMU including accelerometers alone (IMU-A) or in combination with gyroscopes (IMU-G) were mounted on the S1. A reflective marker at S1, and COM calculated from 3D full-body optical analysis, were used to provide reference values. IMU-A provided an accurate and precise estimate of vertical S1 displacement, but IMU-G was required to attain accuracy and precision of < 8 mm (root-mean-squared error and range of displacement deviation) in all directions and with both subtechniques. Further, arm and torso movements affected COM, but not the S1. Hence, S1 displacement was valid for estimating sideways COM displacement, but the systematic amplitude and timing difference between S1 and COM displacement in the anteroposterior and vertical directions inhibits exact calculation of energy fluctuations.

  5. 南水北调项目IMU/DGPS辅助航摄测量技术实践研究%The Research on IMU/DGPS Supported Aerial Photogrammetry in South- to- North Water Diversion Project

    Institute of Scientific and Technical Information of China (English)

    崔迎迎; 梅洋

    2012-01-01

    The paper centers on IMU/DGPS supported aerial photogrammetry and establishes a complete set of programs. Meanwhile the paper discusses GPS base - station distribution and calibration field, explores GPS surveying and mapping, analyses advantages and disadvantages of IMU/DGPS supported aerial photogrammetry and finally puts forward some technical suggestions.%以IMU/DGPS辅助航空摄影测量为研究内容,在系统地总结和阐述IMU/DGPS辅助航空摄影测量的有关原理和方法的基础上,结合南水北调工程建设与管理基础信息建设与应用(一期)项目中的生产实验和工程实践,形成了一套完整的IMU/DGPS辅助航空摄影测量实施方案,并针对应用中的GPS基站布设、检校场和GPS测量等问题进行了探讨和研究。最后,结合项目的成果,分析了IMU/DGPS辅助航空摄影测量技术的优势和不足,并提出该技术使用的建议。

  6. A Study on Application of IMU/DGPS in Production of DOM%IMU/DGPS数据在DOM生产中的应用研究

    Institute of Scientific and Technical Information of China (English)

    赵德文

    2009-01-01

    IMU/DGPS(惯导测量仪/差分全球定位系统)技术航测成图法可直接获取外方位元素,缩短航测成图周期,降低航测成本.通过相应的试验及具体生产的实施,阐明利用该技术获取的控制数据进行1:5万DOM制作的技术流程及作业过程中出现问题的处理方法.

  7. Ka-band InSAR Imaging and Analysis Based on IMU Data

    Directory of Open Access Journals (Sweden)

    Shi Jun

    2014-02-01

    Full Text Available Compared with other bands, the millimeter wave Interferometric Synthetic Aperture Radar (InSAR has high accuracy and small size, which is a hot topic in InSAR research. On the other hand, shorter wavelength causes difficulties in 2D imaging and interferometric phase extraction. In this study, the imaging and phase performance of the streaming Back Projection (BP method combined with IMU data are analyzed and discussed on the basis of actual Ka-band InSAR data. It is found that because the wavelength of the Ka-band is short, it is more sensitive to the antenna phase-center history. To ensure the phase-preserving capacity, the IMU data must be used with accurate motion error compensation. Furthermore, during data processing, we verify the flat-earth-removing capacity of the BP algorithm that calculates and compensates the master and slave antenna phase centers individually.

  8. Statistical Sensor Fusion of a 9-DOF Mems Imu for Indoor Navigation

    Science.gov (United States)

    Chow, J. C. K.

    2017-09-01

    Sensor fusion of a MEMS IMU with a magnetometer is a popular system design, because such 9-DoF (degrees of freedom) systems are capable of achieving drift-free 3D orientation tracking. However, these systems are often vulnerable to ambient magnetic distortions and lack useful position information; in the absence of external position aiding (e.g. satellite/ultra-wideband positioning systems) the dead-reckoned position accuracy from a 9-DoF MEMS IMU deteriorates rapidly due to unmodelled errors. Positioning information is valuable in many satellite-denied geomatics applications (e.g. indoor navigation, location-based services, etc.). This paper proposes an improved 9-DoF IMU indoor pose tracking method using batch optimization. By adopting a robust in-situ user self-calibration approach to model the systematic errors of the accelerometer, gyroscope, and magnetometer simultaneously in a tightly-coupled post-processed least-squares framework, the accuracy of the estimated trajectory from a 9-DoF MEMS IMU can be improved. Through a combination of relative magnetic measurement updates and a robust weight function, the method is able to tolerate a high level of magnetic distortions. The proposed auto-calibration method was tested in-use under various heterogeneous magnetic field conditions to mimic a person walking with the sensor in their pocket, a person checking their phone, and a person walking with a smartwatch. In these experiments, the presented algorithm improved the in-situ dead-reckoning orientation accuracy by 79.8-89.5 % and the dead-reckoned positioning accuracy by 72.9-92.8 %, thus reducing the relative positioning error from metre-level to decimetre-level after ten seconds of integration, without making assumptions about the user's dynamics.

  9. STATISTICAL SENSOR FUSION OF A 9-DOF MEMS IMU FOR INDOOR NAVIGATION

    Directory of Open Access Journals (Sweden)

    J. C. K. Chow

    2017-09-01

    Full Text Available Sensor fusion of a MEMS IMU with a magnetometer is a popular system design, because such 9-DoF (degrees of freedom systems are capable of achieving drift-free 3D orientation tracking. However, these systems are often vulnerable to ambient magnetic distortions and lack useful position information; in the absence of external position aiding (e.g. satellite/ultra-wideband positioning systems the dead-reckoned position accuracy from a 9-DoF MEMS IMU deteriorates rapidly due to unmodelled errors. Positioning information is valuable in many satellite-denied geomatics applications (e.g. indoor navigation, location-based services, etc.. This paper proposes an improved 9-DoF IMU indoor pose tracking method using batch optimization. By adopting a robust in-situ user self-calibration approach to model the systematic errors of the accelerometer, gyroscope, and magnetometer simultaneously in a tightly-coupled post-processed least-squares framework, the accuracy of the estimated trajectory from a 9-DoF MEMS IMU can be improved. Through a combination of relative magnetic measurement updates and a robust weight function, the method is able to tolerate a high level of magnetic distortions. The proposed auto-calibration method was tested in-use under various heterogeneous magnetic field conditions to mimic a person walking with the sensor in their pocket, a person checking their phone, and a person walking with a smartwatch. In these experiments, the presented algorithm improved the in-situ dead-reckoning orientation accuracy by 79.8–89.5 % and the dead-reckoned positioning accuracy by 72.9–92.8 %, thus reducing the relative positioning error from metre-level to decimetre-level after ten seconds of integration, without making assumptions about the user’s dynamics.

  10. Production of an X-band horn after a design of Dick Turrin, W2IMU

    Science.gov (United States)

    Monstein, Christian

    2015-08-01

    While looking for a nice, easy to perform and cheap students' project in 2009, we investigated X-band (8 to 12 GHz) microwave devices. A 5 m parabolic dish antenna and an X-band down-converter were already available, but we had no antenna feed in our tool box. A web search yielded a simple feed horn design and found sketches and descriptions by Dick Turrin (W2IMU) from 1991.

  11. Integration of a multi-camera vision system and strapdown inertial navigation system (SDINS) with a modified Kalman filter.

    Science.gov (United States)

    Parnian, Neda; Golnaraghi, Farid

    2010-01-01

    This paper describes the development of a modified Kalman filter to integrate a multi-camera vision system and strapdown inertial navigation system (SDINS) for tracking a hand-held moving device for slow or nearly static applications over extended periods of time. In this algorithm, the magnitude of the changes in position and velocity are estimated and then added to the previous estimation of the position and velocity, respectively. The experimental results of the hybrid vision/SDINS design show that the position error of the tool tip in all directions is about one millimeter RMS. The proposed Kalman filter removes the effect of the gravitational force in the state-space model. As a result, the resulting error is eliminated and the resulting position is smoother and ripple-free.

  12. A New Continuous Rotation IMU Alignment Algorithm Based on Stochastic Modeling for Cost Effective North-Finding Applications

    Directory of Open Access Journals (Sweden)

    Yun Li

    2016-12-01

    Full Text Available Based on stochastic modeling of Coriolis vibration gyros by the Allan variance technique, this paper discusses Angle Random Walk (ARW, Rate Random Walk (RRW and Markov process gyroscope noises which have significant impacts on the North-finding accuracy. A new continuous rotation alignment algorithm for a Coriolis vibration gyroscope Inertial Measurement Unit (IMU is proposed in this paper, in which the extended observation equations are used for the Kalman filter to enhance the estimation of gyro drift errors, thus improving the north-finding accuracy. Theoretical and numerical comparisons between the proposed algorithm and the traditional ones are presented. The experimental results show that the new continuous rotation alignment algorithm using the extended observation equations in the Kalman filter is more efficient than the traditional two-position alignment method. Using Coriolis vibration gyros with bias instability of 0.1°/h, a north-finding accuracy of 0.1° (1σ is achieved by the new continuous rotation alignment algorithm, compared with 0.6° (1σ north-finding accuracy for the two-position alignment and 1° (1σ for the fixed-position alignment.

  13. Tracking 3D Moving Objects Based on GPS/IMU Navigation Solution, Laser Scanner Point Cloud and GIS Data

    Directory of Open Access Journals (Sweden)

    Siavash Hosseinyalamdary

    2015-07-01

    Full Text Available Monitoring vehicular road traffic is a key component of any autonomous driving platform. Detecting moving objects, and tracking them, is crucial to navigating around objects and predicting their locations and trajectories. Laser sensors provide an excellent observation of the area around vehicles, but the point cloud of objects may be noisy, occluded, and prone to different errors. Consequently, object tracking is an open problem, especially for low-quality point clouds. This paper describes a pipeline to integrate various sensor data and prior information, such as a Geospatial Information System (GIS map, to segment and track moving objects in a scene. We show that even a low-quality GIS map, such as OpenStreetMap (OSM, can improve the tracking accuracy, as well as decrease processing time. A bank of Kalman filters is used to track moving objects in a scene. In addition, we apply non-holonomic constraint to provide a better orientation estimation of moving objects. The results show that moving objects can be correctly detected, and accurately tracked, over time, based on modest quality Light Detection And Ranging (LiDAR data, a coarse GIS map, and a fairly accurate Global Positioning System (GPS and Inertial Measurement Unit (IMU navigation solution.

  14. A New Continuous Rotation IMU Alignment Algorithm Based on Stochastic Modeling for Cost Effective North-Finding Applications

    Science.gov (United States)

    Li, Yun; Wu, Wenqi; Jiang, Qingan; Wang, Jinling

    2016-01-01

    Based on stochastic modeling of Coriolis vibration gyros by the Allan variance technique, this paper discusses Angle Random Walk (ARW), Rate Random Walk (RRW) and Markov process gyroscope noises which have significant impacts on the North-finding accuracy. A new continuous rotation alignment algorithm for a Coriolis vibration gyroscope Inertial Measurement Unit (IMU) is proposed in this paper, in which the extended observation equations are used for the Kalman filter to enhance the estimation of gyro drift errors, thus improving the north-finding accuracy. Theoretical and numerical comparisons between the proposed algorithm and the traditional ones are presented. The experimental results show that the new continuous rotation alignment algorithm using the extended observation equations in the Kalman filter is more efficient than the traditional two-position alignment method. Using Coriolis vibration gyros with bias instability of 0.1°/h, a north-finding accuracy of 0.1° (1σ) is achieved by the new continuous rotation alignment algorithm, compared with 0.6° (1σ) north-finding accuracy for the two-position alignment and 1° (1σ) for the fixed-position alignment. PMID:27983585

  15. GPS/IMU组合定位定向系统设计%Design of GPS/IMU integration for positioning and orientation

    Institute of Scientific and Technical Information of China (English)

    徐勇; 何秀凤

    2004-01-01

    介绍了一种组合低成本的GPS和IMU(Inertial Measurement Unit)来获得高精度姿态、位置和速度信息的方法.文中介绍了GPS/IMU组合系统的设计方案及系统的硬件和软件设计,并给出了实验结果.该组合系统将来安装于炮兵测地车后,不仅可以提高测地的精度,而且在采样率、可靠性等方面比单独采用GPS定位的方法更有优势.

  16. Design and Implementation of Simulator for Strapdown Inertial Navigation System%捷联惯导系统仿真器的设计与实现

    Institute of Scientific and Technical Information of China (English)

    陈敏; 安艳辉; 李晓华

    2012-01-01

    本文研究了捷联惯性导航系统的仿真原理,然后以Matlab为平台,在对捷联惯性导航系统仿真的基础上,分析了在纯捷联惯导情况下导航系统的导航精度。实验结果表明捷联惯性导航系统的导航精度随时间的积累迅速降低,证明了研究组合导航系统的必要性。%This paper studies the simulation theory of Strapdown Inertial Navigation System, then using the Matlab tool eosimulate the Strapdown Inertial Navigation System. The result of the simulation shows that the navigation precision of SINS reducing with time increases and it is necessary to study the integrated navigation system.

  17. Segmentation of human upper body movement using multiple IMU sensors.

    Science.gov (United States)

    Aoki, Takashi; Lin, Jonathan Feng-Shun; Kulic, Dana; Venture, Gentiane

    2016-08-01

    This paper proposes an approach for the segmentation of human body movements measured by inertial measurement unit sensors. Using the angular velocity and linear acceleration measurements directly, without converting to joint angles, we perform segmentation by formulating the problem as a classification problem, and training a classifier to differentiate between motion end-point and within-motion points. The proposed approach is validated with experiments measuring the upper body movement during reaching tasks, demonstrating classification accuracy of over 85.8%.

  18. Application of ASCOT and POS in IMU/DGPS Assisted Aerial Photograph Taking%ASCOT与POS结合在IMU/DGPS辅助航空摄影中的应用

    Institute of Scientific and Technical Information of China (English)

    谢陈; 耿军雪

    2007-01-01

    IMU/DGPS辅助航空摄影是近年来开始广泛应用的航摄新技术,该技术的使用设备十分昂贵,而且,其设备中的航空摄影管理系统不一定是必需的,本文通过改造徕卡的ASCOT系统,使其和APPLANIX公司的POS AV 510 一起完成某摄区的IMU/DGPS辅助航空摄影,充分利用已有的设备,为IMU/DGPS辅助航空摄影提供了一种新的设备配置方案.

  19. Application of IMU / DGPS Auxiliary Aerial Technology in the Production of the Large Scale 3D%IMU/DGPS辅助航摄技术在大比例尺3D生产中的应用

    Institute of Scientific and Technical Information of China (English)

    王晓艳

    2010-01-01

    IMU/DGPS辅助航摄技术在中小比例尺中的应用已趋于成熟.但该技术在大比例尺成图3D生产中的应用案例数量有限.本文结合深圳IMU/DGPS辅助数码航摄及1:2000 3D生产项目,主要阐述了IMU/DGPS辅助航摄技术在大比例尺应用中的技术方案,涉及航空摄影、航测外业和航测内业等方面.

  20. Research on the Design and Simulation on the Low-cost IMU/GPS Integrated Navigation System for Vehicles%低成本IMU/GPS车辆组合导航系统设计与仿真研究

    Institute of Scientific and Technical Information of China (English)

    杨波; 汪广大; 柴艳

    2006-01-01

    设计了一种低成本的IMU/GPS车辆组合导航系统.采用低精度的陀螺仪和加速度计作为惯性测量器件,构成惯性测量装置(IMU);然后,将该IMU与GPS构成组合导航系统,通过设计高效的组合导航算法来提高组合系统的定位精度.实验仿真结果表明,该低成本IMU/GPS车辆组合导航系统具有较高的导航精度,同时有效降低了系统成本.

  1. Study on Improvement of Accuracy in Inertial Photogrammetry by Combining Images with Inertial Measurement Unit

    Science.gov (United States)

    Kawasaki, Hideaki; Anzai, Shojiro; Koizumi, Toshio

    2016-06-01

    Inertial photogrammetry is defined as photogrammetry that involves using a camera on which an inertial measurement unit (IMU) is mounted. In inertial photogrammetry, the position and inclination of a shooting camera are calculated using the IMU. An IMU is characterized by error growth caused by time accumulation because acceleration is integrated with respect to time. This study examines the procedure to estimate the position of the camera accurately while shooting using the IMU and the structure from motion (SfM) technology, which is applied in many fields, such as computer vision. When neither the coordinates of the position of the camera nor those of feature points are known, SfM provides a similar positional relationship between the position of the camera and feature points. Therefore, the actual length of positional coordinates is not determined. If the actual length of the position of the camera is unknown, the camera acceleration is obtained by calculating the second order differential of the position of the camera, with respect to the shooting time. The authors had determined the actual length by assigning the position of IMU to the SfM-calculated position. Hence, accuracy decreased because of the error growth, which was the characteristic feature of IMU. In order to solve this problem, a new calculation method was proposed. Using this method, the difference between the IMU-calculated acceleration and the camera-calculated acceleration can be obtained using the method of least squares, and the magnification required for calculating the actual dimension from the position of the camera can be obtained. The actual length can be calculated by multiplying all the SfM point groups by the obtained magnification factor. This calculation method suppresses the error growth, which is due to the time accumulation in IMU, and improves the accuracy of inertial photogrammetry.

  2. 冗余 MEMS-IMU 误差补偿技术研究%Redundant MEMS-IMU error compensation technology

    Institute of Scientific and Technical Information of China (English)

    邵玉萍; 何昆鹏

    2015-01-01

    为提高惯性导航系统的精度和可靠性,设计了一种基于冗余MEMS-IMU的惯性导航系统(3 MEMS-IMU分别斜置安装在正四面体的3个面上),并针对该系统的惯性测量单元( IMU)进行了误差分析,建立了精确的误差补偿数学模型。在此基础上提出了一种标定方法,给出了计算误差模型参数的推导过程以及各误差参数的数学表达式。通过多组试验验证了该方法简单可靠,可以有效估计出各误差参数,并能有效进行误差补偿,标定精度较高,适用于短时间、低中精度导航系统。%To improve the accuracy and reliability of the inertial navigation system , an inertial navigation system based on redundant MEMS-IMU was designed ( 3 MEMS-IMUs were installed obliquely at three surfaces of a regular tetrahedron ) .And the error of the IMU was analyzed and a precise mathematical model of error compensation was established .A calibration method was proposed , and a detailed derivation of the calculation of error parameters and mathematical expressions of all error parameters were given .Many groups of experiments proved that the method is simple and reliable and can estimate each error parameters effectively , and can carry out error compensation effec-tively, which has high calibration precision , suitable for short-time, low or medium precision inertial navigation system.

  3. Based on IMU/DGPS Navigation Remote Sensing Image Fast Correction Method%基于IMU/DGPS的航空遥感影像快速纠正方法

    Institute of Scientific and Technical Information of China (English)

    马红涛; 余涛; 郑逢斌; 郭丁

    2009-01-01

    论述利用IMU/DGPS系统快速获取外方位元素的原理,介绍在外方位元素支持下的影像快速镶嵌的基本方法,重点说明利用IMU/DGPS系统进行影像的快速正射校正.相关的实验结果表明,文中的方法能在几何精度要求不高的应急事件处理的情况下,快速获取区域的镶嵌影像.

  4. Validity and reliability of an IMU-based method to detect APAs prior to gait initiation.

    Science.gov (United States)

    Mancini, Martina; Chiari, Lorenzo; Holmstrom, Lars; Salarian, Arash; Horak, Fay B

    2016-01-01

    Anticipatory postural adjustments (APAs) prior to gait initiation have been largely studied in traditional, laboratory settings using force plates under the feet to characterize the displacement of the center of pressure. However clinical trials and clinical practice would benefit from a portable, inexpensive method for characterizing APAs. Therefore, the main objectives of this study were (1) to develop a novel, automatic IMU-based method to detect and characterize APAs during gait initiation and (2) to measure its test-retest reliability. Experiment I was carried out in the laboratory to determine the validity of the IMU-based method in 10 subjects with PD (OFF medication) and 12 control subjects. Experiment II was carried out in the clinic, to determine test-retest reliability of the IMU-based method in a different set of 17 early-to-moderate, treated subjects with PD (tested ON medication) and 17 age-matched control subjects. Results showed that gait initiation characteristics (both APAs and 1st step) detected with our novel method were significantly correlated to the characteristics calculated with a force plate and motion analysis system. The size of APAs measured with either inertial sensors or force plate was significantly smaller in subjects with PD than in control subjects (p<0.05). Test-retest reliability for the gait initiation characteristics measured with inertial sensors was moderate-to-excellent (0.56

  5. Wearable IMU for Shoulder Injury Prevention in Overhead Sports

    Directory of Open Access Journals (Sweden)

    Samir A. Rawashdeh

    2016-11-01

    Full Text Available Body-worn inertial sensors have enabled motion capture outside of the laboratory setting. In this work, an inertial measurement unit was attached to the upper arm to track and discriminate between shoulder motion gestures in order to help prevent shoulder over-use injuries in athletics through real-time preventative feedback. We present a detection and classification approach that can be used to count the number of times certain motion gestures occur. The application presented involves tracking baseball throws and volleyball serves, which are common overhead movements that can lead to shoulder and elbow overuse injuries. Eleven subjects are recruited to collect training, testing, and randomized validation data, which include throws, serves, and seven other exercises that serve as a large null class of similar movements, which is analogous to a realistic usage scenario and requires a robust estimator.

  6. Validation of the angular measurements of a new inertial-measurement-unit based rehabilitation system: comparison with state-of-the-art gait analysis

    OpenAIRE

    Leardini, Alberto; Lullini, Giada; Giannini, Sandro; Berti, Lisa; Ortolani, Maurizio; Caravaggi, Paolo

    2014-01-01

    Background Several rehabilitation systems based on inertial measurement units (IMU) are entering the market for the control of exercises and to measure performance progression, particularly for recovery after lower limb orthopaedic treatments. IMU are easy to wear also by the patient alone, but the extent to which IMU’s malpositioning in routine use can affect the accuracy of the measurements is not known. A new such system (Riablo™, CoRehab, Trento, Italy), using audio-visual biofeedback bas...

  7. Data Fusion Algorithms for Multiple Inertial Measurement Units

    Directory of Open Access Journals (Sweden)

    Gérard Lachapelle

    2011-06-01

    Full Text Available A single low cost inertial measurement unit (IMU is often used in conjunction with GPS to increase the accuracy and improve the availability of the navigation solution for a pedestrian navigation system. This paper develops several fusion algorithms for using multiple IMUs to enhance performance. In particular, this research seeks to understand the benefits and detriments of each fusion method in the context of pedestrian navigation. Three fusion methods are proposed. First, all raw IMU measurements are mapped onto a common frame (i.e., a virtual frame and processed in a typical combined GPS-IMU Kalman filter. Second, a large stacked filter is constructed of several IMUs. This filter construction allows for relative information between the IMUs to be used as updates. Third, a federated filter is used to process each IMU as a local filter. The output of each local filter is shared with a master filter, which in turn, shares information back with the local filters. The construction of each filter is discussed and improvements are made to the virtual IMU (VIMU architecture, which is the most commonly used architecture in the literature. Since accuracy and availability are the most important characteristics of a pedestrian navigation system, the analysis of each filter’s performance focuses on these two parameters. Data was collected in two environments, one where GPS signals are moderately attenuated and another where signals are severely attenuated. Accuracy is shown as a function of architecture and the number of IMUs used.

  8. Android Platform for Realtime Gait Tracking Using Inertial Measurement Units

    Science.gov (United States)

    Aqueveque, Pablo; Sobarzo, Sergio; Saavedra, Francisco; Maldonado, Claudio; Gómez, Britam

    2016-01-01

    One of the most important movements performed by the humans is gait. Biomechanical Gait analysis is usually by optical capture systems. However, such systems are expensive and sensitive to light and obstacles. In order to reduce those costs a system based on Inertial Measurements Units (IMU) is proposed. IMU are a good option to make movement analisys indoor with a low post-processing data, allowing to connect those systems to an Android platform. The design is based on two elements: a) The IMU sensors and the b) Android device. The IMU sensor is simple, small (35 x 35 mm), portable and autonomous (7.8 hrs). A resolution of 0.01° in their measurements is obtained, and sends data via Bluetooth link. The Android application works for Android 4.2 or higher, and it is compatible with Bluetooth devices 2.0 or higher. Three IMU sensors send data to a Tablet wirelessly, in order to evaluate the angles evolution for each joint of the leg (hip, knee and ankle). This information is used to calculate gait index and evaluate the gait quality online during the physical therapist is working with the patient. PMID:27990241

  9. Android platform for realtime gait tracking using inertial measurement units

    Directory of Open Access Journals (Sweden)

    Pablo Aqueveque

    2016-07-01

    Full Text Available One of the most important movements performed by the humans is gait. Biomechanical Gait analysis is usually by optical capture systems. However, such systems are expensive and sensitive to light and obstacles. In order to reduce those costs a system based on Inertial Measurements Units (IMU is proposed. IMU are a good option to make movement analisys indoor with a low post-processing data, allowing to connect those systems to an Android platform. The design is based on two elements: a The IMU sensors and the b Android device. The IMU sensor is simple, small (35 x 35 mm, portable and autonomous (7.8 hrs. A resolution of 0.01° in their measurements is obtained, and sends data via Bluetooth link. The Android application works for Android 4.2 or higher, and it is compatible with Bluetooth devices 2.0 or higher. Three IMU sensors send data to a Tablet wirelessly, in order to evaluate the angles evolution for each joint of the leg (hip, knee and ankle. This information is used to calculate gait index and evaluate the gait quality online during the physical therapist is working with the patient.

  10. Android Platform for Realtime Gait Tracking Using Inertial Measurement Units.

    Science.gov (United States)

    Aqueveque, Pablo; Sobarzo, Sergio; Saavedra, Francisco; Maldonado, Claudio; Gómez, Britam

    2016-06-13

    One of the most important movements performed by the humans is gait. Biomechanical Gait analysis is usually by optical capture systems. However, such systems are expensive and sensitive to light and obstacles. In order to reduce those costs a system based on Inertial Measurements Units (IMU) is proposed. IMU are a good option to make movement analisys indoor with a low post-processing data, allowing to connect those systems to an Android platform. The design is based on two elements: a) The IMU sensors and the b) Android device. The IMU sensor is simple, small (35 x 35 mm), portable and autonomous (7.8 hrs). A resolution of 0.01° in their measurements is obtained, and sends data via Bluetooth link. The Android application works for Android 4.2 or higher, and it is compatible with Bluetooth devices 2.0 or higher. Three IMU sensors send data to a Tablet wirelessly, in order to evaluate the angles evolution for each joint of the leg (hip, knee and ankle). This information is used to calculate gait index and evaluate the gait quality online during the physical therapist is working with the patient.

  11. Skew redundant MEMS IMU calibration using a Kalman filter

    Science.gov (United States)

    Jafari, M.; Sahebjameyan, M.; Moshiri, B.; Najafabadi, T. A.

    2015-10-01

    In this paper, a novel calibration procedure for skew redundant inertial measurement units (SRIMUs) based on micro-electro mechanical systems (MEMS) is proposed. A general model of the SRIMU measurements is derived which contains the effects of bias, scale factor error and misalignments. For more accuracy, the effect of lever arms of the accelerometers to the center of the table are modeled and compensated in the calibration procedure. Two separate Kalman filters (KFs) are proposed to perform the estimation of error parameters for gyroscopes and accelerometers. The predictive error minimization (PEM) stochastic modeling method is used to simultaneously model the effect of bias instability and random walk noise on the calibration Kalman filters to diminish the biased estimations. The proposed procedure is simulated numerically and has expected experimental results. The calibration maneuvers are applied using a two-axis angle turntable in a way that the persistency of excitation (PE) condition for parameter estimation is met. For this purpose, a trapezoidal calibration profile is utilized to excite different deterministic error parameters of the accelerometers and a pulse profile is used for the gyroscopes. Furthermore, to evaluate the performance of the proposed KF calibration method, a conventional least squares (LS) calibration procedure is derived for the SRIMUs and the simulation and experimental results compare the functionality of the two proposed methods with each other.

  12. Stochastic modelling and analysis of IMU sensor errors

    Science.gov (United States)

    Zaho, Y.; Horemuz, M.; Sjöberg, L. E.

    2011-12-01

    The performance of a GPS/INS integration system is greatly determined by the ability of stand-alone INS system to determine position and attitude within GPS outage. The positional and attitude precision degrades rapidly during GPS outage due to INS sensor errors. With advantages of low price and volume, the Micro Electrical Mechanical Sensors (MEMS) have been wildly used in GPS/INS integration. Moreover, standalone MEMS can keep a reasonable positional precision only a few seconds due to systematic and random sensor errors. General stochastic error sources existing in inertial sensors can be modelled as (IEEE STD 647, 2006) Quantization Noise, Random Walk, Bias Instability, Rate Random Walk and Rate Ramp. Here we apply different methods to analyze the stochastic sensor errors, i.e. autoregressive modelling, Gauss-Markov process, Power Spectral Density and Allan Variance. Then the tests on a MEMS based inertial measurement unit were carried out with these methods. The results show that different methods give similar estimates of stochastic error model parameters. These values can be used further in the Kalman filter for better navigation accuracy and in the Doppler frequency estimate for faster acquisition after GPS signal outage.

  13. Control Point Layout Schemes for Block Adjustment Based on IMU/GPS in Shenzhen City%深圳市IMU/GP S辅助区域网平差布点方案

    Institute of Scientific and Technical Information of China (English)

    任治敏; 卢永华

    2016-01-01

    This paper selects a set of aerial photographs with the camera position determined by IMU/GPS kinematic positioning, divides the aerotriangulation area based on terrain,and compares aerotriangulation results of different control point layout schemes for different aerotriangulation area.Based on the analysis of the test results,the author put forward the best control point layout scheme for IMU/GPS-supported bundle block adjustment of different terrain in Shenzhen city.%采用深圳市一组带有IMU/GPS导航数据的航摄资料,根据地形划分空三区域,对各个空三区域不同的像控点布设方案产生的空三结果进行对比分析。以此为基础,从理论上得出深圳市各类地形基于IMU/GPS辅助光束法区域网平差最佳布点方案。

  14. Modeling and simulation on temperature performance in fiber optic gyroscope fiber coil of shipborne strapdown inertial navigation system

    Science.gov (United States)

    Wang, Yueze; Ma, Lin; Yu, Hao; Gao, Hongyu; Yuan, Yujie

    2016-10-01

    Compared with the traditional gyros, Fiber optic gyroscope (FOG) based on sagnac effect has the significant features, such as, long life, low cost, wide dynamic range, etc. These features have developed new applications of the gyroscope not only in industrial application area but also in aerospace application area. Now, the FOG has played a very important role in shipborne Strapdown Inertial Navigation System (SINS). The fiber coil, as one of the most critical components in FOG, is extremely sensitive to changes in temperature. Here, by study the environment temperature in shipborne SINS, the temperature performance of the FOG was analyzed. Firstly, on the base of the research about the theory of Shupe non-reciprocal errors caused by temperature, the discrete mathematics formula of the temperature error in FOG of SINS was built .Then the element model of the fiber coil in SINS was built based on the discrete model of the fiber coil in temperature error in FOG. A turn-by-turn quantization temperature bias error model is establish. Finally, based on the temperature models mentioned above, the temperature performance of FOG in shipborne SINS was analyzed. With finite element analysis, numerical simulations were carried out to quantitatively analyze the angular error induced by temperature excitation in SINS. The model was validated by comparing numerical and experimental results.

  15. Coarse Alignment of Marine Strapdown INS Based on the Trajectory Fitting of Gravity Movement in the Inertial Space

    Directory of Open Access Journals (Sweden)

    Lin Zhao

    2016-10-01

    Full Text Available A ship experiences the random motion of sea waves during its travels. Hence, the coarse alignment of the marine strapdown Inertial Navigation System (INS suffers from rocking disturbances such as pitch and roll. In this paper, a novel approach of marine coarse alignment was proposed for avoiding the resulting loss of accuracy from rocking disturbances. Unlike several current techniques, our alignment scheme is intuitional and concise. Moreover, the coarse alignment can be implemented without any external information. The gravity vector and its derivative expressed within the inertial frame can describe the attitude matrix between an inertial frame and the local geographic frame. We address the challenge of calculating the gravity derivative by the least-squares fitting of the trajectory of the gravity movement in the inertial frame. Meanwhile, the integration of angular rates measured by gyroscopes allows one to compute the attitude matrix between the inertial frame and the body frame. The coarse alignment can be thus accomplished by the combination of the above two attitude matrices. The experimental results show that the coarse alignment is effective with high accuracy and stability for demanding marine applications.

  16. 75 FR 74127 - In the Matter of the Review of the Designation of Islamic Movement of Uzbekistan (IMU and Other...

    Science.gov (United States)

    2010-11-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE In the Matter of the Review of the Designation of Islamic Movement of Uzbekistan (IMU and Other Aliases) as a Foreign Terrorist Organization Pursuant to Section 219 of the Immigration and Nationality Act, as...

  17. Simulation of MEMS IMU and GPS Integrated Navigation System%MEMS-IMU/GPS组合导航系统仿真研究

    Institute of Scientific and Technical Information of China (English)

    宋玉珍; 刘炼

    2010-01-01

    微电子机械系统(MEMS)是指可以批量制造的,集微型结构、微型传感器以及信号处理电路、接口、通信和电源于一体的微型器件.MEMS惯性测量单元是采用MEMS技术研制的加速度计和陀螺组合器件,它具有体积小、成本低、可靠性高等优点.首先介绍了微机电惯性测量单元(MEMS-IMU)的发展情况,总结了IMU的基本工作原理;随后对IMU中的主要误差源微机电陀螺进行了统计建模;最后以位置和速度信息为观测值将MEMS-IMU与GPS进行组合导航,并进行了仿真实验,由实验结果可以得出结论:MEMS-IMU不能单独构成导航系统,而与GPS组合后的导航系统精度可以满足一般的导航需求.

  18. Design and implementation of a MEMS-IMU / GPS / GPS integrated navigation system%MEMS-IMU/GPS/GPRS组合导航方案设计与实现

    Institute of Scientific and Technical Information of China (English)

    丰趁得; 刘庆元; 欧野

    2016-01-01

    针对日益增长的低成本导航定位需求,提出了一个MEMS-IMU/GPS/GPRS组合导航方案,以MEMS-IMU模块和SIM908单板机为载体,以GPRS为通讯手段,实时获取GPS/IMU位姿信息.并编写程序分别对GPS和IMU数据进行预处理并以松组合方式进行组合导航数据融合.为验证系统的可靠性和精度,进行了实际静态试验和车载实验,事后数据处理分析结果表明,提出的低成本组合导航系统具有一定的可靠性,导航定位精度达到分米级.

  19. 基于DSP+CPLD的捷联航姿系统设计与实现%Design and Realization of Strapdown AHRS Based on DSP & CPLD

    Institute of Scientific and Technical Information of China (English)

    宋国安; 曾庆化; 张斌; 胡倩倩

    2012-01-01

    针对捷联航姿系统高精度、小型化、高可靠性的发展需求,文中研究并实现了基于DSP+CPLD导航计算机的光纤航姿参考系统,在导航计算机设计中充分体现了DSP处理器实时解算和CPLD控制信号的双重优点.系统软件可实现加电BIT、磁罗差标定、CRC校验的存储器自检、捷联航姿解算和模糊自适应内阻尼卡尔曼滤波等功能.通过大量的试验验证了硬件的可靠性和算法的有效性.样机实验结果表明基于DSP和CPLD导航计算机的捷联惯性航姿系统性能稳定,满足系统的精度设计要求.%For development requirements of high-precision, miniaturization, reliability in the Strapdown AHRS, an optical AHRS based on DSP+CPLD navigation computer was designed and realized. During the design of navigation computer,the dual advantages of the realtime solving function of DSP and signals control of CPLD were considered. Realization of Strapdown AHRS software included fallowing functions,such as power BIT,magnetic compass calibration,CRC memory self-test,AHRS algorithm and Damp Kalman filtering. The Experiments prove that the system hardware is reliable,the software is available. Experiment results showed that the physical prototype of Strapdown AHRS based on DSP and CPLD navigation computer had wonderful performance and it can satisfy the accuracy requirements of required system.

  20. Application of IMU/GPS Assisted Aerial Photogrammetry---A Case Study in Guiyang,China%IMU/GPS辅助航空摄影测量技术方法应用研究--以贵阳市航空摄影测量项目为例

    Institute of Scientific and Technical Information of China (English)

    石平; 张文安

    2016-01-01

    通过贵阳市航空摄影测量项目的实施,形成了一套有效可行的IMU/GPS辅助航空摄影测量技术方法。介绍了项目所采用的检校场的布设方法、IMU/GPS辅助光束法区域网像控布点方法,以及IMU/GPS辅助空中三角测量技术,分析了IMU/GPS辅助空中三角测量和DEM/DOM成果精度,论述了该项目所形成的IMU/GPS辅助航空摄影测量技术方法的适用范围和局限性。

  1. Calibration and Validation of Inertial Measurement Unit for Wave Resolving Drifters

    Science.gov (United States)

    2013-12-01

    multiple microelectromechanical systems ( MEMS ), including a triaxial accelerometer, a triaxial gyroscope , and a triaxial magnetometer. The...14. SUBJECT TERMS Ocean waves, wave buoys, drifters, inertial measurement units, MEMS , sensor validation, reference frames...GPS-based buoy GPS global positioning system GUI graphical user interface IMU inertial measurement unit MCR mouth of the Columbia River MEMS

  2. Accuracy and repeatability of an inertial measurement unit system for field-based occupational studies.

    Science.gov (United States)

    Schall, Mark C; Fethke, Nathan B; Chen, Howard; Oyama, Sakiko; Douphrate, David I

    2016-04-01

    The accuracy and repeatability of an inertial measurement unit (IMU) system for directly measuring trunk angular displacement and upper arm elevation were evaluated over eight hours (i) in comparison to a gold standard, optical motion capture (OMC) system in a laboratory setting, and (ii) during a field-based assessment of dairy parlour work. Sample-to-sample root mean square differences between the IMU and OMC system ranged from 4.1° to 6.6° for the trunk and 7.2°-12.1° for the upper arm depending on the processing method. Estimates of mean angular displacement and angular displacement variation (difference between the 90th and 10th percentiles of angular displacement) were observed to change IMU system may serve as an acceptable instrument for directly measuring trunk and upper arm postures in field-based occupational exposure assessment studies with long sampling durations. Practitioner Summary: Few studies have evaluated inertial measurement unit (IMU) systems in the field or over long sampling durations. Results of this study indicate that the IMU system evaluated has reasonably good accuracy and repeatability for use in a field setting over a long sampling duration.

  3. Rancang Bangun Inertial Measurement Unit Untuk Unmanned Aerial Vehicles “Quadrotor”

    Directory of Open Access Journals (Sweden)

    Muhammad Alfiansyah

    2012-09-01

    Full Text Available Teknologi robot udara quadrotor semakin berkembang pesat. Salah satu bagian yang marak dikembangkan adalah sensor orientasinya atau yang umum disebut sebagai Inertial Measurement Unit (IMU.  Permasalahan pada IMU yang umum terjadi antara lain adalah ketidakmampuan processing unit untuk mengolah data dengan cepat (output data rate rendah, beban komputasi yang tinggi (algoritma penggabungan data sensor yang berat, luaran Accelerometer ber-noise tinggi yang umumnya berasal dari getaran body UAV dan luaran Gyroscope yang mengalami drift. Pada tugas akhir ini diciptakan sebuah IMU menggunakan Mikrokontroller STM32F4 sebagai pemroses data dan metode determinasi oerientasi dengan representasi Direction Cosine Matrices sebagai  algoritma penyatuan data dan penentu luaran orientasi. Dari hasil pengujian menggunakan gimbal elektronik , Didapati RMS Error Statis paling kecil sebesar 1.030 (pitch, 0.060 (roll, 0.100 (yaw dan RMS Error Dinamis paling kecil sebesar 1.930 (pitch, 1.790 (roll, 1.420 (yaw

  4. Redundancy management of multiple KT-70 inertial measurement units applicable to the space shuttle

    Science.gov (United States)

    Cook, L. J.

    1975-01-01

    Results of an investigation of velocity failure detection and isolation for 3 inertial measuring units (IMU) and 2 inertial measuring units (IMU) configurations are presented. The failure detection and isolation algorithm performance was highly successful and most types of velocity errors were detected and isolated. The failure detection and isolation algorithm also included attitude FDI but was not evaluated because of the lack of time and low resolution in the gimbal angle synchro outputs. The shuttle KT-70 IMUs will have dual-speed resolvers and high resolution gimbal angle readouts. It was demonstrated by these tests that a single computer utilizing a serial data bus can successfully control a redundant 3-IMU system and perform FDI.

  5. Comparative performance analysis of M-IMU/EMG and voice user interfaces for assistive robots.

    Science.gov (United States)

    Laureiti, Clemente; Cordella, Francesca; di Luzio, Francesco Scotto; Saccucci, Stefano; Davalli, Angelo; Sacchetti, Rinaldo; Zollo, Loredana

    2017-07-01

    People with a high level of disability experience great difficulties to perform activities of daily living and resort to their residual motor functions in order to operate assistive devices. The commercially available interfaces used to control assistive manipulators are typically based on joysticks and can be used only by subjects with upper-limb residual mobilities. Many other solutions can be found in the literature, based on the use of multiple sensory systems for detecting the human motion intention and state. Some of them require a high cognitive workload for the user. Some others are more intuitive and easy to use but have not been widely investigated in terms of usability and user acceptance. The objective of this work is to propose an intuitive and robust user interface for assistive robots, not obtrusive for the user and easily adaptable for subjects with different levels of disability. The proposed user interface is based on the combination of M-IMU and EMG for the continuous control of an arm-hand robotic system by means of M-IMUs. The system has been experimentally validated and compared to a standard voice interface. Sixteen healthy subjects volunteered to participate in the study: 8 subjects used the combined M-IMU/EMG robot control, and 8 subjects used the voice control. The arm-hand robotic system made of the KUKA LWR 4+ and the IH2 Azzurra hand was controlled to accomplish the daily living task of drinking. Performance indices and evaluation scales were adopted to assess performance of the two interfaces.

  6. An innovative procedure for calibration of strapdown electro-optical sensors onboard unmanned air vehicles.

    Science.gov (United States)

    Fasano, Giancarmine; Accardo, Domenico; Moccia, Antonio; Rispoli, Attilio

    2010-01-01

    This paper presents an innovative method for estimating the attitude of airborne electro-optical cameras with respect to the onboard autonomous navigation unit. The procedure is based on the use of attitude measurements under static conditions taken by an inertial unit and carrier-phase differential Global Positioning System to obtain accurate camera position estimates in the aircraft body reference frame, while image analysis allows line-of-sight unit vectors in the camera based reference frame to be computed. The method has been applied to the alignment of the visible and infrared cameras installed onboard the experimental aircraft of the Italian Aerospace Research Center and adopted for in-flight obstacle detection and collision avoidance. Results show an angular uncertainty on the order of 0.1° (rms).

  7. An Innovative Procedure for Calibration of Strapdown Electro-Optical Sensors Onboard Unmanned Air Vehicles

    Directory of Open Access Journals (Sweden)

    Attilio Rispoli

    2010-01-01

    Full Text Available This paper presents an innovative method for estimating the attitude of airborne electro-optical cameras with respect to the onboard autonomous navigation unit. The procedure is based on the use of attitude measurements under static conditions taken by an inertial unit and carrier-phase differential Global Positioning System to obtain accurate camera position estimates in the aircraft body reference frame, while image analysis allows line-of-sight unit vectors in the camera based reference frame to be computed. The method has been applied to the alignment of the visible and infrared cameras installed onboard the experimental aircraft of the Italian Aerospace Research Center and adopted for in-flight obstacle detection and collision avoidance. Results show an angular uncertainty on the order of 0.1° (rms.

  8. Layout optimization of shipborne IMU based on genetic algorithm%基于遗传算法的舰载IMU优化布局

    Institute of Scientific and Technical Information of China (English)

    郑荣才; 杨功流; 陈超英; 翁海娜

    2007-01-01

    IMU is used to provide shipborne weapon systems with accurate attitudes and to monitor deck deformation real time. It is worth researching further to optimize the location and number of IMU. The paper presented the principle of multi-IMU layout optimization and created its mathematical model. The IMU layout optimization was solved using Genetic Algorithm. The simulation results show that the number of IMU for shipborne weapon systems is decreased. The layout of shipborne IMU is an important factor that impacts the estimation accuracy of deck deformation, and the estimation accuracy is improved greatly by IMU layout optimization.%惯性测量单元(IMU)用来为舰载武器系统提供准确的姿态并实时监测舰船甲板的变形,对其数目和位置进行优化具有重要的实用价值.提出了多IMU优化布局的原则,建立了舰载IMU优化布局的数学模型,采用遗传算法对IMU的布局进行了优化求解.仿真结果表明,舰载IMU的布局是影响甲板变形估计精度的一个重要因素,通过对IMU的布局进行优化,减少了舰载武器系统所需IMU的数量;利用优化布局后IMU的输出信息对全舰甲板变形进行估计,估计精度有很大提高.

  9. 遥测测试中的IMU初始对准问题%Algorithms for Initial Alignment of IMU in Telemetering

    Institute of Scientific and Technical Information of China (English)

    曹少珺; 孙发鱼

    2007-01-01

    本文在分析惯性测量单元(IMU)的解算算法的基础上,利用姿态转动分析了遥测测试中惯性测量单元(IMU)数据解算的初始四元数提取方法,并对其进行推导和验证,仿真结果表明了该方法的有效性.

  10. The Application of Aerial Surveying on Line Engineering Surveys Aided with IMU/DGPS%IMU/DGPS辅助航空摄影测量在线路工程测量的应用

    Institute of Scientific and Technical Information of China (English)

    张寰; 贾满

    2009-01-01

    介绍了IMU/DGPS辅助航空摄影测量,并进行了其在带状区域空中三角测量(空三)的试验,分析并比较了各种空三方法的加密精度.结果表明在大比例尺图的带状区域生产中,IMU/DGPS辅助空中三角测量方法比GPS辅助空中三角测量方法要有优势,能够满足我国现行航空摄影测量规范对航测生产的精度要求.

  11. IMU/DGPS辅助航摄项目中GPS基站布设方案实验研究%The Research on GPS Base-station Distribution in IMU/DGPS Supported Photogrammetry

    Institute of Scientific and Technical Information of China (English)

    李学友; 孙占义

    2005-01-01

    IMU/DGPS辅助航空摄影测量中,需要布设地面GPS基站,通过基站GPS接收机与机载GPS接收机获得的数据进行事后差分处理,获取高精度的机载天线3维坐标值.通过大量的实验,对IMU/DGPS辅助航空摄影测量中如何布设基站,基站与摄区的最大距离,需要多少个基站等问题进行研究、分析和总结.

  12. Third Decade of Health professional education at the International Medical University: driven by the 3 I’s of IMU*

    Directory of Open Access Journals (Sweden)

    Siang Tong Kew

    2013-03-01

    Full Text Available Building on two decades as a private health professional university, the International Medical University prepares for the third decade, taking stock of the challenges in changing epidemiology and patternof disease, changing demography and healthcare, as well as explosion in knowledge and information technology. The Global Independent Commission1 provided a framework for instructional and institutional reforms, and the IMU will use its 3 I’s (insight, imagination &innovation in adopting these measures. Some of theinstructional reforms are already in place, others needto be further nurtured and promoted. In its third decade,competency based curriculum, inter-professionallearning, IT, global collaboration, educationalresources, new professionalism and emphasis on qualityimprovement will help ensure IMU train and producecompetent, caring and ethical health professionals fit totackle 21st century challenges.

  13. Front-Crawl Instantaneous Velocity Estimation Using a Wearable Inertial Measurement Unit

    Directory of Open Access Journals (Sweden)

    Kamiar Aminian

    2012-09-01

    Full Text Available Monitoring the performance is a crucial task for elite sports during both training and competition. Velocity is the key parameter of performance in swimming, but swimming performance evaluation remains immature due to the complexities of measurements in water. The purpose of this study is to use a single inertial measurement unit (IMU to estimate front crawl velocity. Thirty swimmers, equipped with an IMU on the sacrum, each performed four different velocity trials of 25 m in ascending order. A tethered speedometer was used as the velocity measurement reference. Deployment of biomechanical constraints of front crawl locomotion and change detection framework on acceleration signal paved the way for a drift-free integration of forward acceleration using IMU to estimate the swimmers velocity. A difference of 0.6 ± 5.4 cm·s−1 on mean cycle velocity and an RMS difference of 11.3 cm·s−1 in instantaneous velocity estimation were observed between IMU and the reference. The most important contribution of the study is a new practical tool for objective evaluation of swimming performance. A single body-worn IMU provides timely feedback for coaches and sport scientists without any complicated setup or restraining the swimmer’s natural technique.

  14. Real-time integration of a tactical-grade IMU and GPS for high-accuracy positioning and navigation

    Science.gov (United States)

    Petovello, Mark G.

    2003-10-01

    The integration of the Global Positioning System (CPS) and Inertial Navigation Systems (INSs) is often used to provide accurate positioning and navigation information. For applications requiring the highest accuracy, the quality of the inertial sensors required is usually assumed to be very high. This dissertation investigates the integration of CPS with a tactical-grade Inertial Measurement Unit (IMU) for centimetre-level navigation in real-time. Different GPS/INS integration strategies are investigated to assess their relative performance in terms of position and velocity accuracy during partial and complete data outages, carrier phase ambiguity resolution after such data outages, and the overall statistical reliability of the system. In terms of statistical reliability, the traditional equations used in dynamic systems are redeveloped in light of some practical considerations, including centralized and decentralized filter architectures, and sequential versus simultaneous measurement updating. Results show that the integrated solution outperforms the GPS-only approach in all areas. The difference between loose and tight integration strategies was most significant for ambiguity resolution and system reliability. The integrated solution is capable of providing decimetre-level accuracy or better for durations of about five or ten seconds when a complete or partial CPS outage is simulated. This level of accuracy, extended over longer time intervals, is shown to reduce the time required to resolve the L1 ambiguities by an average of about 50% or more for data outages as long as 30 seconds when using a tight integration strategy. More importantly, the reliability of the ambiguity resolution process is improved with the integrated system. Statistical reliability parameters are also dramatically better when using the integrated system with the ability of detecting a single-cycle cycle slip being better and more consistent, relative to GPS-only. The effect of undetected

  15. Epson Toyocom开发兼具高度准确及稳定的小型IMU

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ Epson Toyocom宣布目前正在开发一款极小型但具备高度准确稳定之惯性测量装置(IMU),准备于未来推出市场.此IMU采用Epson Toyocom在开发QMEMS石英角速度传感器时所累积的技术.

  16. Development of the wireless ultra-miniaturized inertial measurement unit WB-4: preliminary performance evaluation.

    Science.gov (United States)

    Lin, Zhuohua; Zecca, Massimiliano; Sessa, Salvatore; Bartolomeo, Luca; Ishii, Hiroyuki; Takanishi, Atsuo

    2011-01-01

    This paper presents the preliminary performance evaluation of our new wireless ultra-miniaturized inertial measurement unit (IMU) WB-4 by compared with the Vicon motion capture system. The WB-4 IMU primarily contains a mother board for motion sensing, a Bluetooth module for wireless data transmission with PC, and a Li-Polymer battery for power supply. The mother board is provided with a microcontroller and 9-axis inertial sensors (miniaturized MEMS accelerometer, gyroscope and magnetometer) to measure orientation. A quaternion-based extended Kalman filter (EKF) integrated with an R-Adaptive algorithm for automatic estimation of the measurement covariance matrix is implemented for the sensor fusion to retrieve the attitude. The experimental results showed that the wireless ultra-miniaturized WB-4 IMU could provide high accuracy performance at the angles of roll and pitch. The yaw angle which has reasonable performance needs to be further evaluated.

  17. RECALMIN II. Eight years of hospitalisation in Internal Medicine Units (2007-2014). What has changed?

    Science.gov (United States)

    Zapatero-Gaviria, A; Barba-Martín, R; Canora Lebrato, J; Fernández-Pérez, C; Gómez-Huelgas, R; Bernal-Sobrino, J L; Díez-Manglano, J; Marco-Martínez, J; Elola-Somoza, F J

    2017-08-30

    To analyse the evolution of care provided by the internal medicine units (IMU) of the Spanish National Health System from 2007 to 2014. We analysed all discharges from the IMU of the Spanish National Health System in 2007 and 2014, using the Minimum Basic Data Set. We compared the risk factors by episode, mortality and readmissions between the two periods. We prepared specific fits for the risk for mortality and readmissions in heart failure, pneumonia and chronic obstructive pulmonary disease, as well as the Charlson index for all activity. Discharges from the IMU between the two periods increased 14%. The average patient age increased by 2.8 years (71.2±17.1 vs. 74±16.2; pMedicina Interna (SEMI). All rights reserved.

  18. An Increase in Estimation Accuracy Position Determination of Inertial Measurement Units

    Directory of Open Access Journals (Sweden)

    Beran Ladislav

    2016-01-01

    Full Text Available This paper deals with an increase in measurement accuracy of the Inertial Measurement Units (IMU. In the Inertial Navigation Systems (INS a fusion of gyroscopes, accelerometers and in some cases magnetometers are typically used. The typical problem of cheap IMU is non-stationary offset and high level of noise. The next problem of IMU is a problem with a bumpy floor. For this case it is necessary to a have high quality chassis to eliminate additional noise. Also, it is possible to eliminate this noise by using some algorithm, but results are still poor. These properties lead to the inaccurate position estimation in the integration process. Even a small offset error leads to a big mistake in position determination and grows quickly with a time. This research is focused on the elimination of these poor properties and increase of accuracy of position estimation using Kalman Filtration.

  19. An Accurate GPS-IMU/DR Data Fusion Method for Driverless Car Based on a Set of Predictive Models and Grid Constraints.

    Science.gov (United States)

    Wang, Shiyao; Deng, Zhidong; Yin, Gang

    2016-02-24

    A high-performance differential global positioning system (GPS)  receiver with real time kinematics provides absolute localization for driverless cars. However, it is not only susceptible to multipath effect but also unable to effectively fulfill precise error correction in a wide range of driving areas. This paper proposes an accurate GPS-inertial measurement unit (IMU)/dead reckoning (DR) data fusion method based on a set of predictive models and occupancy grid constraints. First, we employ a set of autoregressive and moving average (ARMA) equations that have different structural parameters to build maximum likelihood models of raw navigation. Second, both grid constraints and spatial consensus checks on all predictive results and current measurements are required to have removal of outliers. Navigation data that satisfy stationary stochastic process are further fused to achieve accurate localization results. Third, the standard deviation of multimodal data fusion can be pre-specified by grid size. Finally, we perform a lot of field tests on a diversity of real urban scenarios. The experimental results demonstrate that the method can significantly smooth small jumps in bias and considerably reduce accumulated position errors due to DR. With low computational complexity, the position accuracy of our method surpasses existing state-of-the-arts on the same dataset and the new data fusion method is practically applied in our driverless car.

  20. Effect of digital precision temperature control on FOG IMU performance%数字式精密温控对FOG IMU性能的影响

    Institute of Scientific and Technical Information of China (English)

    任卓恒; 宋凝芳; 崔佳涛

    2007-01-01

    以战术级光纤陀螺(FOG,Fiber-Optic Gyro)惯性测量组合(IMU,Inertial Measurement Unit)为研究对象,分析了环境温度与其测量精度的关系.为抑制外界温度对IMU的干扰,提出了一种实用的IMU温度控制方法,即根据IMU的热分析与仿真,优化温度控制方案和控制算法,并依此方法为IMU设计了基于模糊PID(Proportion Integration Differentiation)算法的数字式温控系统,研究了有温控和无温控对陀螺和加速度计测量精度的影响.试验表明,对IMU进行精密温控,改善了惯性器件的热环境,有助于提高IMU的综合性能.

  1. An Accurate GPS-IMU/DR Data Fusion Method for Driverless Car Based on a Set of Predictive Models and Grid Constraints

    Directory of Open Access Journals (Sweden)

    Shiyao Wang

    2016-02-01

    Full Text Available A high-performance differential global positioning system (GPS  receiver with real time kinematics provides absolute localization for driverless cars. However, it is not only susceptible to multipath effect but also unable to effectively fulfill precise error correction in a wide range of driving areas. This paper proposes an accurate GPS–inertial measurement unit (IMU/dead reckoning (DR data fusion method based on a set of predictive models and occupancy grid constraints. First, we employ a set of autoregressive and moving average (ARMA equations that have different structural parameters to build maximum likelihood models of raw navigation. Second, both grid constraints and spatial consensus checks on all predictive results and current measurements are required to have removal of outliers. Navigation data that satisfy stationary stochastic process are further fused to achieve accurate localization results. Third, the standard deviation of multimodal data fusion can be pre-specified by grid size. Finally, we perform a lot of field tests on a diversity of real urban scenarios. The experimental results demonstrate that the method can significantly smooth small jumps in bias and considerably reduce accumulated position errors due to DR. With low computational complexity, the position accuracy of our method surpasses existing state-of-the-arts on the same dataset and the new data fusion method is practically applied in our driverless car.

  2. An Accurate GPS-IMU/DR Data Fusion Method for Driverless Car Based on a Set of Predictive Models and Grid Constraints

    Science.gov (United States)

    Wang, Shiyao; Deng, Zhidong; Yin, Gang

    2016-01-01

    A high-performance differential global positioning system (GPS)  receiver with real time kinematics provides absolute localization for driverless cars. However, it is not only susceptible to multipath effect but also unable to effectively fulfill precise error correction in a wide range of driving areas. This paper proposes an accurate GPS–inertial measurement unit (IMU)/dead reckoning (DR) data fusion method based on a set of predictive models and occupancy grid constraints. First, we employ a set of autoregressive and moving average (ARMA) equations that have different structural parameters to build maximum likelihood models of raw navigation. Second, both grid constraints and spatial consensus checks on all predictive results and current measurements are required to have removal of outliers. Navigation data that satisfy stationary stochastic process are further fused to achieve accurate localization results. Third, the standard deviation of multimodal data fusion can be pre-specified by grid size. Finally, we perform a lot of field tests on a diversity of real urban scenarios. The experimental results demonstrate that the method can significantly smooth small jumps in bias and considerably reduce accumulated position errors due to DR. With low computational complexity, the position accuracy of our method surpasses existing state-of-the-arts on the same dataset and the new data fusion method is practically applied in our driverless car. PMID:26927108

  3. Validity of an inertial measurement unit to assess pelvic orientation angles during gait, sit-stand transfers and step-up transfers: Comparison with an optoelectronic motion capture system.

    Science.gov (United States)

    Bolink, S A A N; Naisas, H; Senden, R; Essers, H; Heyligers, I C; Meijer, K; Grimm, B

    2016-03-01

    An inertial measurement unit (IMU) allows kinematic evaluation of human motion with fewer operational constraints than a gold standard optoelectronic motion capture (MOCAP) system. The study's aim was to compare IMU and MOCAP measurements of dynamic pelvic orientation angles during different activities of daily life (ADL): gait, sit-to-stand (STS) transfers and block step-up (BS) transfers. A single IMU was attached onto the lower back in seventeen healthy participants (8F/9 M, age 19-31 years; BMI IMU and MOCAP by Bland-Altman plots demonstrated that measurements were between 2SD of the absolute difference and Pearson's correlation coefficients were between 0.85 and 0.94. Frontal plane pelvic angle estimations achieved a RMSE in the range of [2.7°-4.5°] and sagittal plane measurements achieved a RMSE in the range of [2.7°-8.9°] which were both lowest in gait. Waveform peak detection times demonstrated ICCs between 0.96 and 1.00. These results are in accordance to other studies comparing IMU and MOCAP measurements with different applications and suggest that an IMU is a valid tool to measure dynamic pelvic angles during various activities of daily life which could be applied to monitor rehabilitation in a wide variety of musculoskeletal disorders.

  4. Pedestrian mobile mapping system for indoor environments based on MEMS IMU and range camera

    Science.gov (United States)

    Haala, N.; Fritsch, D.; Peter, M.; Khosravani, A. M.

    2011-12-01

    This paper describes an approach for the modeling of building interiors based on a mobile device, which integrates modules for pedestrian navigation and low-cost 3D data collection. Personal navigation is realized by a foot mounted low cost MEMS IMU, while 3D data capture for subsequent indoor modeling uses a low cost range camera, which was originally developed for gaming applications. Both steps, navigation and modeling, are supported by additional information as provided from the automatic interpretation of evacuation plans. Such emergency plans are compulsory for public buildings in a number of countries. They consist of an approximate floor plan, the current position and escape routes. Additionally, semantic information like stairs, elevators or the floor number is available. After the user has captured an image of such a floor plan, this information is made explicit again by an automatic raster-to-vector-conversion. The resulting coarse indoor model then provides constraints at stairs or building walls, which restrict the potential movement of the user. This information is then used to support pedestrian navigation by eliminating drift effects of the used low-cost sensor system. The approximate indoor building model additionally provides a priori information during subsequent indoor modeling. Within this process, the low cost range camera Kinect is used for the collection of multiple 3D point clouds, which are aligned by a suitable matching step and then further analyzed to refine the coarse building model.

  5. GPS/UWB/MEMS-IMU tightly coupled navigation with improved robust Kalman filter

    Science.gov (United States)

    Li, Zengke; Chang, Guobin; Gao, Jingxiang; Wang, Jian; Hernandez, Alberto

    2016-12-01

    The integration of Global Positioning System (GPS) with Inertial Navigation System (INS) has been very intensively developed and widely applied in multiple areas. To further enhance the reliability and availability of GPS/INS integrated navigation in GPS challenging environment, range observation through ultra-wideband (UWB) is introduced in GPS/INS tightly coupled navigation. An improved robust Kalman filter is proposed and used to resist the influence of gross error from UWB observation in GPS/UWB/IMU tightly coupled navigation. The variance of the squared Mahalanobis distance in moving window is calculated, which brings as new judgement factor for gross errors in order to decrease the rate of false outlier identification. A simulation analysis shows that the improved robust Kalman filter is able to correctly identify gross errors and the rate of false judgment as zero. In order to validate the new robust filter, a real experiment is conducted. The results indicate that the improved robust Kalman filter used in GPS/UWB/INS tightly coupled navigation is able to remove the harmful effect of gross error in UWB observation. It clearly illustrates that the improved robust Kalman filter is very effective, and all the simulated small and large gross errors added to UWB distance observation are successfully identified.

  6. Integration of a MEMS Inertial Measuring Unit with a MEMS Magnetometer for 3D Orientation Estimation

    DEFF Research Database (Denmark)

    Cai, Junping; Malureanu, Christian; Andersen, Niels Lervad

    2011-01-01

    This paper presents an algorithm for combining the measurements of a MEMS Inertial Measurement Unit (IMU) and a MEMS magnetometer. The measurements are done using a special designed and customized miniature detecting system for 3D orientation estimation, and position tracking...

  7. Research on Calibration Field for IMU/DGPS Assisted Large Scale Aerial Photograph%IMU/DGPS辅助大比例尺航空摄影检效场布设的研究

    Institute of Scientific and Technical Information of China (English)

    吕亚军

    2009-01-01

    IMU/DGPS辅助航空摄影飞行时,需要同时飞行检校场,检校场的作用、飞行频率、飞行中的注意事项经国内外广大学者专家研讨已基本成为定论.通过检校场作用并结合实验数据探讨切合实际作业检校场的布设方案及实测方法.

  8. IMU/DGPS辅助航测技术在1∶2000航测成图中的应用及成图精度分析

    Institute of Scientific and Technical Information of China (English)

    梁龙帅; 杨国创

    2015-01-01

    以广东省佛山市高明区测区1∶2000航测成图技术方案为例,简要介绍IMU/DGPS辅助航空摄影测量技术在大比例尺测图中的应用,并对IMU/DGPS辅助空三加密成果进行精度分析.通过外业检测数据对DLG进行数学精度评定,论证采用IMU/DGPS辅助航空摄影测量技术在大比例尺测图中的数学精度.

  9. Strapdown optical seeker characteristics and multi-dimension optimal guidance law%捷联式光学导引头特性与多维度最优制导律

    Institute of Scientific and Technical Information of China (English)

    张跃; 储海荣

    2013-01-01

    为实现捷联式光学成像导引头与制导系统一体化设计,建立了全捷联制导与控制系统,根据捷联导引头特性进行制导与控制原理研究。首先,建立了全捷联导引头与陀螺的数学模型;接着,针对捷联导引头无法精确提取视线角速率的问题,提出姿态驾驶仪与视线角积分比例导引相结合的控制与制导方案,并分析了导引头体视线角、刻度因数、导航比和系统稳定区域之间的关系;然后,推导了全捷联制导系统最优制导律以提高制导系统响应速度;最后,进行了控制与制导系统飞行仿真,仿真结果表明:捷联式制导与控制系统能对静止与运动目标(速度为60 km/h )进行有效攻击,最大射击误差分别为1.49 m与2.62 m;系统误差、陀螺零偏与零偏稳定性对制导系统精度影响较大。捷联导引头制导与控制系统能满足空对地系统对静止与低速运动目标的攻击要求。%In order to realize strapdown optical imaging seeker and guidance system integrated design, strapdown guidance and control system were established. According to the characteristics of strapdown seeker, guidance and control principle were studied. The models of strapdown seeker and gyro were established. For the problem of strapdown seeker can't extract the line-of-sight angular rate precisely, the control and guidance scheme of combining of attitude autopilot and LOS integral proportional navigation was proposed, and the relationship between body line of sight (BLOS), scale factor, navigation ratio and system stability region were analyzed. In order to improve system response speed, strapdown guidance system optimal guidance law was deduced. In the end, flight simulation were done, and the results show that strapdown guidance and control systems can attack on stationary and moving (60 km/h) targets effectively. The maximum firing errors were 1.49 m and 2.62 m respectively. System errors

  10. Preferred gait and walk-run transition speeds in ostriches measured using GPS-IMU sensors.

    Science.gov (United States)

    Daley, Monica A; Channon, Anthony J; Nolan, Grant S; Hall, Jade

    2016-10-15

    The ostrich (Struthio camelus) is widely appreciated as a fast and agile bipedal athlete, and is a useful comparative bipedal model for human locomotion. Here, we used GPS-IMU sensors to measure naturally selected gait dynamics of ostriches roaming freely over a wide range of speeds in an open field and developed a quantitative method for distinguishing walking and running using accelerometry. We compared freely selected gait-speed distributions with previous laboratory measures of gait dynamics and energetics. We also measured the walk-run and run-walk transition speeds and compared them with those reported for humans. We found that ostriches prefer to walk remarkably slowly, with a narrow walking speed distribution consistent with minimizing cost of transport (CoT) according to a rigid-legged walking model. The dimensionless speeds of the walk-run and run-walk transitions are slower than those observed in humans. Unlike humans, ostriches transition to a run well below the mechanical limit necessitating an aerial phase, as predicted by a compass-gait walking model. When running, ostriches use a broad speed distribution, consistent with previous observations that ostriches are relatively economical runners and have a flat curve for CoT against speed. In contrast, horses exhibit U-shaped curves for CoT against speed, with a narrow speed range within each gait for minimizing CoT. Overall, the gait dynamics of ostriches moving freely over natural terrain are consistent with previous lab-based measures of locomotion. Nonetheless, ostriches, like humans, exhibit a gait-transition hysteresis that is not explained by steady-state locomotor dynamics and energetics. Further study is required to understand the dynamics of gait transitions.

  11. A LiDAR and IMU Integrated Indoor Navigation System for UAVs and Its Application in Real-Time Pipeline Classification.

    Science.gov (United States)

    Kumar, G Ajay; Patil, Ashok Kumar; Patil, Rekha; Park, Seong Sill; Chai, Young Ho

    2017-06-02

    Mapping the environment of a vehicle and localizing a vehicle within that unknown environment are complex issues. Although many approaches based on various types of sensory inputs and computational concepts have been successfully utilized for ground robot localization, there is difficulty in localizing an unmanned aerial vehicle (UAV) due to variation in altitude and motion dynamics. This paper proposes a robust and efficient indoor mapping and localization solution for a UAV integrated with low-cost Light Detection and Ranging (LiDAR) and Inertial Measurement Unit (IMU) sensors. Considering the advantage of the typical geometric structure of indoor environments, the planar position of UAVs can be efficiently calculated from a point-to-point scan matching algorithm using measurements from a horizontally scanning primary LiDAR. The altitude of the UAV with respect to the floor can be estimated accurately using a vertically scanning secondary LiDAR scanner, which is mounted orthogonally to the primary LiDAR. Furthermore, a Kalman filter is used to derive the 3D position by fusing primary and secondary LiDAR data. Additionally, this work presents a novel method for its application in the real-time classification of a pipeline in an indoor map by integrating the proposed navigation approach. Classification of the pipeline is based on the pipe radius estimation considering the region of interest (ROI) and the typical angle. The ROI is selected by finding the nearest neighbors of the selected seed point in the pipeline point cloud, and the typical angle is estimated with the directional histogram. Experimental results are provided to determine the feasibility of the proposed navigation system and its integration with real-time application in industrial plant engineering.

  12. A LiDAR and IMU Integrated Indoor Navigation System for UAVs and Its Application in Real-Time Pipeline Classification

    Science.gov (United States)

    Kumar, G. Ajay; Patil, Ashok Kumar; Patil, Rekha; Park, Seong Sill; Chai, Young Ho

    2017-01-01

    Mapping the environment of a vehicle and localizing a vehicle within that unknown environment are complex issues. Although many approaches based on various types of sensory inputs and computational concepts have been successfully utilized for ground robot localization, there is difficulty in localizing an unmanned aerial vehicle (UAV) due to variation in altitude and motion dynamics. This paper proposes a robust and efficient indoor mapping and localization solution for a UAV integrated with low-cost Light Detection and Ranging (LiDAR) and Inertial Measurement Unit (IMU) sensors. Considering the advantage of the typical geometric structure of indoor environments, the planar position of UAVs can be efficiently calculated from a point-to-point scan matching algorithm using measurements from a horizontally scanning primary LiDAR. The altitude of the UAV with respect to the floor can be estimated accurately using a vertically scanning secondary LiDAR scanner, which is mounted orthogonally to the primary LiDAR. Furthermore, a Kalman filter is used to derive the 3D position by fusing primary and secondary LiDAR data. Additionally, this work presents a novel method for its application in the real-time classification of a pipeline in an indoor map by integrating the proposed navigation approach. Classification of the pipeline is based on the pipe radius estimation considering the region of interest (ROI) and the typical angle. The ROI is selected by finding the nearest neighbors of the selected seed point in the pipeline point cloud, and the typical angle is estimated with the directional histogram. Experimental results are provided to determine the feasibility of the proposed navigation system and its integration with real-time application in industrial plant engineering. PMID:28574474

  13. Thermal Assessment of Sunlight Impinging on OSIRIS-REx OCAMS PolyCam, OTES, and IMU-Sunshade MLI Blankets in Flight

    Science.gov (United States)

    Choi, Michael K.

    2017-01-01

    The NASA Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) spacecraft was successfully launched into orbit on September 8, 2016. It is traveling to a near-Earth asteroid (101955) Bennu, study it in detail, and bring back a pristine sample to Earth for scientific analyses. At the Outbound Cruise nominal spacecraft attitude, with Sun on +X, sunlight impinges on the OSIRIS-REx camera suite (OCAMS) PolyCam sunshade multilayer insulation (MLI) with microporous black polytetrafluoroethylene (PTFE), a portion of the PolyCam optics support tube (MLI with germanium black Kapton (GBK)), a portion of the OSIRIS-REx Thermal Emission Spectrometer (OTES) sunshade (MLI with GBK), the Inertia Measurement Unit (IMU) sunshade (MLI with GBK), and the OSIRIS-REx Laser Altimeter (OLA) sunshade (MLI with GBK). Sunlight is reflected or scattered by the above MLIs to the other components on the forward (+Z) deck. It illuminates the forward deck. A detailed thermal assessment on the solar impingement has been performed for the Proximity Ops at the asteroid, Touch-and-Go (TAG) sample acquisition, and Return Cruise mission phases.The OSIRIS-REx Outbound Cruise flight temperature telemetry and USM_3_DPC_0_CURRENT flight currenttelemetry data have been analyzed. It is evident that at the nominal Outbound Cruise spacecraft Sun-pointing attitude(i.e., Sun on +X), sunlight impinging on the PolyCam, OTES, IMU-sunshade and OLA-sunshade MLIs is reflected orscattered to the forward deck and components on the forward deck. It illuminates the forward deck. The StowCam imageof Day 265 2016 also provided an evidence. The reflected or scattered sunlight cause warming to the forward deck andcomponents on its +Z side. It may also contribute to degradation of thermal coatings over the mission life. It is a factorthat the OVIRS detector operating temperature exceeds the 105K maximum AFT limit. The OVIRS PrincipalInvestigator indicated that it is not optimum

  14. MEMS IMU/GNSS 联邦卡尔曼滤波中的基于四元数的约束算法%Quaternion based constrained algorithm in federated Kalman filtering for MEMS IMU/GNSS

    Institute of Scientific and Technical Information of China (English)

    刘华; 刘彤

    2013-01-01

      当全球导航卫星系统(GNSS)失效时,微硅机械(MEMS)惯性测量单元(IMU)与GNSS 组合而成的导航系统性能会下降。针对于陆地车辆的导航应用,建立了一个联邦卡尔曼滤波器,四元数是其中一个局部滤波器的部分待估计状态。四元数所得到推算的沿车辆机体坐标系的加速度约束扩展了滤波器的观测量。车载试验表明,与传统滤波算法相比,使用该算法可使三维位置导航精度在 GNSS 信号失效30 s 时提高25%,姿态和速度精度也相应的提高。%  The performance of MEMS IMU/GNSS integrated system would degrade with outages of GNSS signal. For land vehicle applications, a federated Kalman filter was established. The quaternion was employed as part of states in one of the local filters. The acceleration constraint derived from quaternion was applied along the vehicle’s body frame to expand observables in the filter. The field test shows that, compared with conventional filtering algorithms, the proposed algorithm brings 25% performance improvement in three-dimension(3D) positioning during 30 s GNSS outages. The accuracy of attitude and velocity is improved as well.

  15. Control system of satellite TV antenna of strapdown shipborne%捷联式船载卫星电视天线控制系统

    Institute of Scientific and Technical Information of China (English)

    秦爱民; 闫英敏; 闫建生; 靳英卫

    2011-01-01

    With the progress of the society and the improvements of information technology, people need more TV programmes through satellite networks while moving. A strapdown shipborne satellite TV antenna control system based on DSP is introduced. The architectures of the software and hardware of the control system are given, and the functions of different components are described in detail. The stabilization and the automatic tracking are realized in this antenna control system for satellite television.%随着社会的进步和信息化技术的提高,人们对移动中通过卫星网路接收卫星电视节目的需求越来越大.介绍了基于DSP的捷联式船载卫星电视天线控制系统,阐述了系统软硬件的结构及各部分的功能,实现了船载卫星电视天线的稳定与自动跟踪卫星.

  16. Introduction of a Photogrammetric Camera System for Rpas with Highly Accurate Gnss/imu Information for Standardized Workflows

    Science.gov (United States)

    Kraft, T.; Geßner, M.; Meißner, H.; Przybilla, H. J.; Gerke, M.

    2016-03-01

    In this paper we present the evaluation of DLR's modular airborne camera system MACS-Micro for remotely piloted aircraft system (RPAS) with a maximum takeoff weight (MTOW) less than 5kg. The main focus is on standardized calibration and test procedures as well as on standardized photogrammetric workflows as a proof of feasibility for this aerial camera concept. The prototype consists of an industrial grade frame imaging camera and a compact GNSS/IMU solution which are operated by an embedded PC. The camera has been calibrated pre- and post- flight using a three dimensional test field. The validation of the latest prototype is done by a traditional photogrammetric evaluation of an aerial survey using 39 ground control points. The results, concerning geometric and radiometric features of the present system concept as well as the quality of the aero triangulation, fulfill many of the aimed keyspecifications.

  17. ADIS16405 IMU 在四旋翼飞行器姿态测量的应用

    Institute of Scientific and Technical Information of China (English)

    冯伟峰

    2013-01-01

      本文针对四旋翼飞行器的姿态测量,利用 ADI 公司的 ADIS16405惯性测量单元(IMU,Inertial measurement unit)测量飞行器的惯性量,然后解算姿态角。本文利用 IMU 采集数据,由嵌入式系统读取并通过串口发送到 PC 机上,在 MATLAB 软件上绘制出采集数据并解算姿态角图像。使用 ADIS16405,使系统具有操作方便,精度高,电路简单的优点。

  18. 浅谈IMU/DGPS技术在1∶10000比例尺地形图测绘中的应用%Discussion on the Application of IMU/DGPS Technology in Surveying and Mapping of 1∶10000 Topographic Map

    Institute of Scientific and Technical Information of China (English)

    乔炜; 王宝山

    2011-01-01

    通过IMU/DGPS技术在实际测绘生产项目中的应用,研究该技术条件下1∶10 000比例尺地形图测绘外业像控布设方案,试验、分析内业空三加密精度,调整像控方案,最终为IMU/DGPS技术在1∶10 000比例尺地形图测绘中的应用提供相关的技术参考。%Through the application of IMU/DGPS technology in practical surveying and mapping production project,this paper studied the layout plan for field photograph control survey of 1∶10000 topographic map,tested and analyzed the accuracy of triangulation,and optimized the scheme of photograph control survey.Finally,it provided the technical reference for the application of IMU/DGPS technology in surveying and mapping of 1∶10000 topographic map.

  19. 惯导轨迹发生器误差引入研究%Simulation of Full Account Error in Strap-down Inertial Navigation Trajectory Generator

    Institute of Scientific and Technical Information of China (English)

    杨彬; 金毅; 高娜; 吴训忠

    2015-01-01

    As the traditional strap-down inertial navigation trajectory generators have some problems such as only considering white noise or not in all round way when importing error, a new trajectory generator which takes a full account of error is put forward. Using trajectory generator to create ideal output, importing the error which is modeled from real devices, the final outputs which are much close to the reality has been got. the traditional trajectory generators and the new one are compared for analyzing.The result demonstrates that the new trajectory generator is more reliable and practical than the traditional one.%轨迹发生器为捷联惯导算法程序提供仿真测试数据。选定理想轨迹,用捷联惯导原理逆向解算出元件输出,引入误差后输入捷联惯导算法程序,得到解算轨迹。针对传统捷联惯导轨迹发生器引入误差不全面的问题,提出全面考虑误差的新型轨迹发生器。用元件真实数据分析出各项误差,将各项误差引入理想元件输出,得到较传统捷联惯导轨迹发生器更加接近真实情况的轨迹数据。仿真结果表明,新型轨迹发生器较传统轨迹发生器更加接近真实情况,是一种可靠的捷联惯导轨迹发生器。

  20. Correlated NOS-Imu and myf5 expression by satellite cells in mdx mouse muscle regeneration during NOS manipulation and deflazacort treatment.

    Science.gov (United States)

    Anderson, Judy E; Vargas, Cinthya

    2003-06-01

    Satellite cells, muscle precursor cells in skeletal muscle, are normally quiescent and become activated by disease or injury. A lack of dystrophin and changes in the expression or activity of neuronal nitric oxide synthase (NOS-I) affect the timing of activation in vivo. Nitric oxide synthase inhibition delays muscle repair in normal mice, and worsens muscular dystrophy in the mdx mouse, a genetic homologue of Duchenne muscular dystrophy. However, the potential role of activation and repair events mediated by nitric oxide in determining the outcome of steroid or other treatments for muscular dystrophy is not clear. We tested the hypothesis that the extent of repair in dystrophic muscles of mdx mice is partly dependent on NOS-Imu expression and activity. Myotube formation in regenerating muscle was promoted by deflazacort treatment of mdx dystrophic mice (PImu mRNA expression and activity were present in satellite cells and very new myotubes of regenerating and dystrophic muscle. Deflazacort treatment resulted in increased NOS-Imu expression in regenerating muscles in a strong and specific correlation with myf5 expression (r=0.95, PImu and myf5 expression in the diaphragm without affecting the diameter of non-regenerating fibres. These in vivo studies suggest that gains in NOS-Imu expression and nitric oxide synthase activity in satellite cells can increase the extent and speed of repair, even in the absence of dystrophin in muscle fibres. NOS-Imu may be a useful therapeutic target to augment the effects of steroidal or other treatments of muscular dystrophy.

  1. 基于 IMU 模块的救援机器人姿态显示系统设计%Design of rescue robot posture display system based on IMU module

    Institute of Scientific and Technical Information of China (English)

    曹宇; 宋爱国; 纪鹏; 郝小蕾; 熊鹏文

    2015-01-01

    M ini IM U姿态传感器中带有三轴陀螺仪和三轴加速度计,利用其模块放置在机器人可以实现机器人的姿态显示。履带式机器人在灾后进行巡检搜救,对陌生的地形情况,姿态信息显得极为重要。对此,将M ini IM U 模块连接在机器人主控板上面,在飞思卡尔DP512单片机μC/OS‐II操作系统中,将数据整合转发给上位机,上位机软件接受到数据信息后,进行数据处理,再用OpenGL虚拟现实技术将机器人姿态复原在上位机中。完成整个设计后,实际让机器人进行旋转、攀爬,和在上位机中得到的数据进行对比测量实验,用误差分析的方法对实验结果分析及评估,具有较强的实时性、准确性、可靠性。%Mini IMU owns three‐axis gyroscope and triaxial accelerometer ,so the robot posture can be displayed with it put in the robot .When crawler‐type robot searches and rescues after catastrophe ,the posture is vital to the unfamiliar topography .To solving this problem ,we connect Mini IMU with main control circuit board ,and the posture data within μC/OS‐II operation system of Freescale singlechip are sent to control box .The control box translate the data after receive them .Finally the robot posture can be displayed by OpenGL technology on the screen of the control box . When the design is completed ,the robot was controlled to rotate ,climb ,and comparing the data received in the upper computer .The result of experiment is analyzed and assessed according to the error analysis .The system is timely , accurate and reliable .

  2. Novel Field Calibration Through Rotation in Six-position for FOG-IMU%光纤陀螺IMU的六位置旋转现场标定新方法

    Institute of Scientific and Technical Information of China (English)

    刘百奇; 房建成

    2008-01-01

    针对光纤陀螺惯性测量单元(Inertial Measurement Unit,IMU)的误差系数随时间推移而变化的问题,本文提出一种光纤陀螺IMU的六位置旋转现场高精度标定新方法,该方法在使用现场将光纤陀螺IMU在六个位置上进行十二次旋转,然后根据光纤陀螺IMU的误差模型建立42个非线性输入输出方程,通过旋转积分和对称位置误差相消,消除方程中的非线性项,最终求解出陀螺标度因数、陀螺常值漂移、陀螺安装误差和加速度计常值偏置等15个误差系数.实验结果表明,该方法可在没有精密转台的现场实现光纤陀螺IMU的精确标定,其标定精度与基于精密转台的标定精度相当.

  3. Cervical Coupling Motion Characteristics in Healthy People Using a Wireless Inertial Measurement Unit

    OpenAIRE

    Hyunho Kim; Sang-Hoon Shin; Jeong-Kyun Kim; Young-Jae Park; Hwan-Sup Oh; Young-Bae Park

    2013-01-01

    Objective. The objectives were to show the feasibility of a wireless microelectromechanical system inertial measurement unit (MEMS-IMU) to assess the time-domain characteristics of cervical motion that are clinically useful to evaluate cervical spine movement. Methods. Cervical spine movements were measured in 18 subjects with wireless IMUs. All rotation data are presented in the Euler angle system. Amount of coupling motions was evaluated by calculating the average angle ratio and the maximu...

  4. Attitude and gyro bias estimation by the rotation of an inertial measurement unit

    Science.gov (United States)

    Wu, Zheming; Sun, Zhenguo; Zhang, Wenzeng; Chen, Qiang

    2015-12-01

    In navigation applications, the presence of an unknown bias in the measurement of rate gyros is a key performance-limiting factor. In order to estimate the gyro bias and improve the accuracy of attitude measurement, we proposed a new method which uses the rotation of an inertial measurement unit, which is independent from rigid body motion. By actively changing the orientation of the inertial measurement unit (IMU), the proposed method generates sufficient relations between the gyro bias and tilt angle (roll and pitch) error via ridge body dynamics, and the gyro bias, including the bias that causes the heading error, can be estimated and compensated. The rotation inertial measurement unit method makes the gravity vector measured from the IMU continuously change in a body-fixed frame. By theoretically analyzing the mathematic model, the convergence of the attitude and gyro bias to the true values is proven. The proposed method provides a good attitude estimation using only measurements from an IMU, when other sensors such as magnetometers and GPS are unreliable. The performance of the proposed method is illustrated under realistic robotic motions and the results demonstrate an improvement in the accuracy of the attitude estimation.

  5. IMU and Multiple RGB-D Camera Fusion for Assisting Indoor Stop-and-Go 3D Terrestrial Laser Scanning

    Directory of Open Access Journals (Sweden)

    Jacky C.K. Chow

    2014-07-01

    Full Text Available Autonomous Simultaneous Localization and Mapping (SLAM is an important topic in many engineering fields. Since stop-and-go systems are typically slow and full-kinematic systems may lack accuracy and integrity, this paper presents a novel hybrid “continuous stop-and-go” mobile mapping system called Scannect. A 3D terrestrial LiDAR system is integrated with a MEMS IMU and two Microsoft Kinect sensors to map indoor urban environments. The Kinects’ depth maps were processed using a new point-to-plane ICP that minimizes the reprojection error of the infrared camera and projector pair in an implicit iterative extended Kalman filter (IEKF. A new formulation of the 5-point visual odometry method is tightly coupled in the implicit IEKF without increasing the dimensions of the state space. The Scannect can map and navigate in areas with textureless walls and provides an effective means for mapping large areas with lots of occlusions. Mapping long corridors (total travel distance of 120 m took approximately 30 minutes and achieved a Mean Radial Spherical Error of 17 cm before smoothing or global optimization.

  6. Forward kinematics using IMU on-body sensor network for mobile analysis of human kinematics.

    Science.gov (United States)

    Taylor, Thomas; Ko, Seungoh; Mastrangelo, Carlos; Bamberg, Stacy J Morris

    2013-01-01

    The feasibility of large network inertial measurement units (IMUs) are evaluated for purposes requiring feedback. A series of wireless IMUs were attached to a human lower-limb laboratory model outfitted with joint angle encoders. The goal was to discover if large networks of wireless IMUs can give realtime joint orientation data while still maintaining an acceptable degree of accuracy.

  7. High-rate precise point positioning (PPP) to measure seismic wave motions: An experimental comparison of GPS PPP with inertial measurement units

    Science.gov (United States)

    Xu, Peiliang; Shi, Chuang; Fang, Rongxin; Liu, Jingnan; Niu, Xiaoji; Zhang, Quan; Yanagidani, Takashi

    2013-04-01

    High-rate GPS has been widely used to construct displacement waveforms and to invert for source parameters of earthquakes. Almost all works on internal and external evaluation of high-rate GPS accuracy are based on GPS relative positioning. We build an experimental platform to externally evaluate the accuracy of 50 Hz PPP displacement waveforms. Since the shake table allows motion in any of six degrees of freedom, we install an inertial measurement unit (IMU) to measure the attitude of the platform and transform the IMU displacements into the GPS coordinate system. The experimental results have shown that high-rate PPP can produce absolute horizontal displacement waveforms at the accuracy of 2 to 4 millimeters and absolute vertical displacement waveforms at the sub-centimeter level of accuracy within a short period of time. The significance of the experiments indicates that high-rate PPP is capable of detecting absolute seismic displacement waveforms at the same high accuracy as GPS relative positioning techniques but requires no fixed datum station. We have also found a small scaling error of IMU and a small time offset of misalignment between high-rate PPP and IMU displacement waveforms by comparing the amplitudes of and cross-correlating both the displacement waveforms. For more details on this talk, one can now get access to the on-line-first version of our Journal of Geodesy paper: J Geod, DOI 10.1007/s00190-012-0606-z

  8. Adaptive Kalman filter for indoor localization using Bluetooth Low Energy and inertial measurement unit.

    Science.gov (United States)

    Yoon, Paul K; Zihajehzadeh, Shaghayegh; Bong-Soo Kang; Park, Edward J

    2015-08-01

    This paper proposes a novel indoor localization method using the Bluetooth Low Energy (BLE) and an inertial measurement unit (IMU). The multipath and non-line-of-sight errors from low-power wireless localization systems commonly result in outliers, affecting the positioning accuracy. We address this problem by adaptively weighting the estimates from the IMU and BLE in our proposed cascaded Kalman filter (KF). The positioning accuracy is further improved with the Rauch-Tung-Striebel smoother. The performance of the proposed algorithm is compared against that of the standard KF experimentally. The results show that the proposed algorithm can maintain high accuracy for position tracking the sensor in the presence of the outliers.

  9. Research and Simulation on the Alignment of IMU/GPS Integrated Navigation System for Shells on Moving Base%基于弹载IMU/GPS组合导航系统的动基座对准研究与仿真

    Institute of Scientific and Technical Information of China (English)

    杨波; 秦永元

    2006-01-01

    对基于弹载IMU/GPS组合导航系统的动基座对准问题进行了研究与仿真;首先,分析了弹载IMU与GPS的系统误差,建立获得了其系统误差模型;然后,利用卡尔曼滤波技术,设计了弹载IMU/GPS组合导航系统的动基座对准算法;仿真结果表明,在初始误差较大的情况下,经过360秒的动基座对准,IMU的姿态角误差可降至10个角秒,同时位置和速度误差也得到了有效修正,从而证明该动基座对准算法是行之有效的.

  10. Is a standalone inertial measurement unit accurate and precise enough for quantification of movement symmetry in the horse?

    DEFF Research Database (Denmark)

    Brighton, Charlotte; Olsen, Emil; Pfau, Thilo

    2015-01-01

    Standalone ‘low-cost’ inertial measurement units (IMUs) could facilitate large-scale studies into establishing minimal important differences (MID) for orthopaedic deficits (lameness) in horses. We investigated accuracy and limits of agreement (LoA) after correction of magnitude-dependent differen......Standalone ‘low-cost’ inertial measurement units (IMUs) could facilitate large-scale studies into establishing minimal important differences (MID) for orthopaedic deficits (lameness) in horses. We investigated accuracy and limits of agreement (LoA) after correction of magnitude......-dependent differences of a standalone 6 degree-of-freedom IMU compared with an established IMU-based gait analysis system (MTx) in six horses for two anatomical landmarks (sacrum and sternum). Established symmetry measures were calculated from vertical displacement: symmetry index (SI), difference between minima (Min...

  11. Angular Motion Estimation Using Dynamic Models in a Gyro-Free Inertial Measurement Unit

    Directory of Open Access Journals (Sweden)

    Otmar Loffeld

    2012-04-01

    Full Text Available In this paper, we summarize the results of using dynamic models borrowed from tracking theory in describing the time evolution of the state vector to have an estimate of the angular motion in a gyro-free inertial measurement unit (GF-IMU. The GF-IMU is a special type inertial measurement unit (IMU that uses only a set of accelerometers in inferring the angular motion. Using distributed accelerometers, we get an angular information vector (AIV composed of angular acceleration and quadratic angular velocity terms. We use a Kalman filter approach to estimate the angular velocity vector since it is not expressed explicitly within the AIV. The bias parameters inherent in the accelerometers measurements’ produce a biased AIV and hence the AIV bias parameters are estimated within an augmented state vector. Using dynamic models, the appended bias parameters of the AIV become observable and hence we can have unbiased angular motion estimate. Moreover, a good model is required to extract the maximum amount of information from the observation. Observability analysis is done to determine the conditions for having an observable state space model. For higher grades of accelerometers and under relatively higher sampling frequency, the error of accelerometer measurements is dominated by the noise error. Consequently, simulations are conducted on two models, one has bias parameters appended in the state space model and the other is a reduced model without bias parameters.

  12. Bilateral step length estimation using a single inertial measurement unit attached to the pelvis

    Directory of Open Access Journals (Sweden)

    Köse Alper

    2012-02-01

    Full Text Available Abstract Background The estimation of the spatio-temporal gait parameters is of primary importance in both physical activity monitoring and clinical contexts. A method for estimating step length bilaterally, during level walking, using a single inertial measurement unit (IMU attached to the pelvis is proposed. In contrast to previous studies, based either on a simplified representation of the human gait mechanics or on a general linear regressive model, the proposed method estimates the step length directly from the integration of the acceleration along the direction of progression. Methods The IMU was placed at pelvis level fixed to the subject's belt on the right side. The method was validated using measurements from a stereo-photogrammetric system as a gold standard on nine subjects walking ten laps along a closed loop track of about 25 m, varying their speed. For each loop, only the IMU data recorded in a 4 m long portion of the track included in the calibrated volume of the SP system, were used for the analysis. The method takes advantage of the cyclic nature of gait and it requires an accurate determination of the foot contact instances. A combination of a Kalman filter and of an optimally filtered direct and reverse integration applied to the IMU signals formed a single novel method (Kalman and Optimally filtered Step length Estimation - KOSE method. A correction of the IMU displacement due to the pelvic rotation occurring in gait was implemented to estimate the step length and the traversed distance. Results The step length was estimated for all subjects with less than 3% error. Traversed distance was assessed with less than 2% error. Conclusions The proposed method provided estimates of step length and traversed distance more accurate than any other method applied to measurements obtained from a single IMU that can be found in the literature. In healthy subjects, it is reasonable to expect that, errors in traversed distance estimation

  13. Direct Location of Infrared Images Based on GPS/IMU%基于GPS/IMU的红外影像直接定位技术

    Institute of Scientific and Technical Information of China (English)

    彭希隆; 赵红; 范永弘; 刘军

    2012-01-01

    Studying the fast target location of infrared images without control points is propitious to exert the potential of infrared remote sensing in surveying and mapping usage. Firstly, the principle and method of GPS/ IMU based target location was introduced, then the feasibility of multiple infrared images forward intersection and GPS/IMU assisted infrared images bundle block adjustment were verified through experiment, and at the same time the causes of error were analyzed. The result of the experiments showed that the aerial infrared remote sensing with the integrated GPS/IMU system can meet the accuracy requirements of the target detection as well as early warning and it has practical value.%研究无控制点情况下的红外影像目标快速定位技术,有利于发挥红外遥感的测绘应用潜力.首先介绍了基于GPS/IMU的目标定位原理与方法;然后实验验证了红外影像多像前方交会和GPS/IMU辅助红外影像光束法区域网平差的可行性;并分析了误差产生的原因.实验证明,航空红外遥感在GPS/IMU组合系统的配合下,能满足目标探测与预警的精度要求,具有实用价值.

  14. The flexibility of UV-inducible mutation in Deinococcus ficus as evidenced by the existence of the imuB-dnaE2 gene cassette and generation of superior feather degrading bacteria.

    Science.gov (United States)

    Zeng, You-Hong; Shen, Fo-Ting; Tan, Chen-Chung; Huang, Chieh-Chen; Young, Chiu-Chung

    2011-12-20

    The lexA-imuB-dnaE2 gene cassette contributing to the TLS (translesion synthesis) polymerase activity and can easily cause mutation after DNA damage in many bacteria. But it was previously thought that TLS polymerase activity was unlikely to exist in the radio-resistant genus Deinococcus. In our preliminary studies, the lexA-imuB-dnaE2 gene cassette was found in a newly isolated feather-degrading Deinococcus ficus. Here we have attempted to determine the imuB gene sequence from another Deinococcus species namely D. grandis, by using the newly designed primers. The destroying of either imuB or dnaE2 gene in D. ficus leads to the increase in UV sensitivity and decrease in UV-induced mutations, which demonstrated the existence of TLS polymerase activity in D. ficus. In the presence of lexA-imuB-dnaE2, it is possible to obtain mutants with various keratinolytic activities after UV exposure. The keratinolytic activity of mutant strain CC-ZG207 increased by approximately twofold during growth in liquid feather medium. In contrast, the mutant strain CC-ZG227 showed only half of the keratinolytic activity compared with the wild type strain. By utilizing SDS-PAGE and zymogram profile analysis, the change in the protease activity was observed. We have proposed that the superior mutants of D. ficus can be created under UV stress, which is mediated by the lexA-imuB-dnaE2 gene cassette.

  15. Trends of GPS and MEMS-IMU Integrated Navigation System%GPS与MEMS-IMU组合导航技术发展现状

    Institute of Scientific and Technical Information of China (English)

    安亮; 王可东

    2008-01-01

    介绍了硅微惯性测量单元(MEMS-IMU)的发展和应用情况,针对目前低成本、小型化的应用要求,分析了GPS和MEMS-IMU各自的优缺点和进行组合导航的可行性.提出了GPS与MEMS-IMU的组合模式,并介绍了组合导航计算机的工作原理和组合导航系统所涉及的关键技术.

  16. Line-of-sight angular rate decoupling and estimation of strapdown optical seeker%捷联式光学导引头视线角速率解耦与估计

    Institute of Scientific and Technical Information of China (English)

    孙婷婷; 储海荣; 贾宏光; 张跃; 李岩

    2014-01-01

    为准确估计捷联导引头视线角速率,建立了全捷联导引头数学模型,根据弹目运动相对关系进行视线角速率解耦与估计算法研究。首先,建立了全捷联导引头数学模型,并利用Taylor级数对其进行线性化;接着,根据弹目运动几何学与坐标系相对关系推导视线角速率解耦算法;然后,针对捷联导引头无法直接测量体视线角速率的问题,提出微分+稳态Kalman滤波方法估计体视线角速率;最后,建立视线角速率解耦与估计算法验证系统并进行仿真实验,结果表明:解耦算法绝对误差小于5×10-5 rad/s,相对误差小于0.3%,验证了解耦算法的正确性;在包含导引头数学模型的条件下,采用角频率为19.2 rad/s的稳态Kalman滤波器,视线角速率估计误差小于4×10-3 rad/s,较直接微分方法的估计误差提高近一个量级。视线角速率解耦与估计算法同时能满足制导系统对精度与动态性能的要求。%In order to accurately estimate the line-of-sight (LOS) angular rate of the strapdown seeker, strapdown seeker mathematical model was established, decoupling and estimation algorithm of LOS angular rate was based on the movement of the missile and target relative relationship. Firstly, a mathematical model of the strapdown seeker was established, and the Taylor series was used for its linearization. Secondly, according to the movement of the missile and target geometry and coordinate system relative relationship, the LOS angular rate decoupling algorithm was derived. Strapdown seeker can not directly measure the body line-of-sight (BLOS) angular rate, differential coefficient+steady-state Kalman filter was proposed to estimate the BLOS angular rate. Finally, LOS angular rate decoupling and estimation algorithm verification system was established and simulation experiment was carried out. The results showed that, the absolute error of decoupling algorithm was less

  17. Design and Simulation Research of a Spherical Robot Based on Strap-down Inertial Navigation%基于捷联惯导的球形机器人设计与仿真研究

    Institute of Scientific and Technical Information of China (English)

    杨安

    2012-01-01

    Fully closed and omnidirectional movement are the prominent merits of an outdoor spherical robot, which are especially suitable for being used in some specific areas. Aiming at difficulty of obtaining information and problem of independent navigation hard to achieve during designing at present, the spherical robot based on strap-down inertial navigation was designed. The outdoor omnidirectional movement was achieved by the robot, through adopting a mechanical structure driven by composite of gravity deviation and inertial moment, designing ARM + FPGA as the core controller based on strap-down inertial navigation system. The spherical robot dynamics was analysed, the controller simulated, and the problems of its outdoor navigation and movement control are solved. Qualifications are provided for practical application of the sperical robot.%全封闭与全方位运动是球形移动机器人的突出优点,非常适用于一些特定领域.针对目前球形机器人设计中获取信息困难与自主导航难以实现的问题,设计了基于捷联惯导的球形机器人.采用重心偏摆与惯性力矩复合驱动的机械结构,设计以ARM+FPGA为核心的控制系统,基于捷联惯导实现机器人在室外环境的全向运动.对球形机器人进行了动力学分析与控制系统仿真,成功解决了球形机器人在室外的定位与运动控制问题,为球形机器人的实际应用提供了条件.

  18. 采用捷联激光探测器的制导火箭比例导引实现方法%PNG law analysis for strapdown laser detector guided rocket

    Institute of Scientific and Technical Information of China (English)

    王磊; 朱伯立

    2013-01-01

    A guidance control scheme based on strapdown laser detector and proportional navigation guidance (PNG) for rocket projectile was presented in details since the precise guidance improvement requirement. Because the strapdown detector can only measure the error angle between airframe axis and target directly and could not provide the inertial line-of-sight (LOS) angular rate necessarily to PNG, a LOS rate algorithm using detector′s error angle and airframe attitude rate from onboard gyro was proposed. A two-loop acceleration autopilot was designed with respect to the autopilot-guidance match principle. The non-dimensional miss distance analysis and trajectory simulation results validate that the proposed approach is feasible.%围绕制式火箭弹精确制导改造的需求,提出了一种采用捷联激光探测器和比例导引的火箭弹制导控制方案。针对捷联探测器只能测量弹轴相对于目标的偏差角而无法提供比例导引所需的惯性视线角速度信号的难题,研究了基于捷联探测器测量的误差角和弹体姿态角速度信号的弹目视线角速度信号提取算法。在制导控制系统内部,基于自动驾驶仪与制导律相匹配的原则,设计了两回路过载自动驾驶仪。无量纲脱靶量分析与攻击静止目标的弹道仿真结果验证了所提方案的可行性。

  19. Sampling and Control Circuit Board for an Inertial Measurement Unit

    Science.gov (United States)

    Chelmins, David T (Inventor); Powis, Richard T., Jr. (Inventor); Sands, Obed (Inventor)

    2016-01-01

    A circuit board that serves as a control and sampling interface to an inertial measurement unit ("IMU") is provided. The circuit board is also configured to interface with a local oscillator and an external trigger pulse. The circuit board is further configured to receive the external trigger pulse from an external source that time aligns the local oscillator and initiates sampling of the inertial measurement device for data at precise time intervals based on pulses from the local oscillator. The sampled data may be synchronized by the circuit board with other sensors of a navigation system via the trigger pulse.

  20. Estimation of IMU and MARG orientation using a gradient descent algorithm.

    Science.gov (United States)

    Madgwick, Sebastian O H; Harrison, Andrew J L; Vaidyanathan, Andrew

    2011-01-01

    This paper presents a novel orientation algorithm designed to support a computationally efficient, wearable inertial human motion tracking system for rehabilitation applications. It is applicable to inertial measurement units (IMUs) consisting of tri-axis gyroscopes and accelerometers, and magnetic angular rate and gravity (MARG) sensor arrays that also include tri-axis magnetometers. The MARG implementation incorporates magnetic distortion compensation. The algorithm uses a quaternion representation, allowing accelerometer and magnetometer data to be used in an analytically derived and optimised gradient descent algorithm to compute the direction of the gyroscope measurement error as a quaternion derivative. Performance has been evaluated empirically using a commercially available orientation sensor and reference measurements of orientation obtained using an optical measurement system. Performance was also benchmarked against the propriety Kalman-based algorithm of orientation sensor. Results indicate the algorithm achieves levels of accuracy matching that of the Kalman based algorithm; < 0.8° static RMS error, < 1.7° dynamic RMS error. The implications of the low computational load and ability to operate at small sampling rates significantly reduces the hardware and power necessary for wearable inertial movement tracking, enabling the creation of lightweight, inexpensive systems capable of functioning for extended periods of time.

  1. Optimization-Based Sensor Fusion of GNSS and IMU Using a Moving Horizon Approach

    Science.gov (United States)

    Girrbach, Fabian; Hol, Jeroen D.; Bellusci, Giovanni; Diehl, Moritz

    2017-01-01

    The rise of autonomous systems operating close to humans imposes new challenges in terms of robustness and precision on the estimation and control algorithms. Approaches based on nonlinear optimization, such as moving horizon estimation, have been shown to improve the accuracy of the estimated solution compared to traditional filter techniques. This paper introduces an optimization-based framework for multi-sensor fusion following a moving horizon scheme. The framework is applied to the often occurring estimation problem of motion tracking by fusing measurements of a global navigation satellite system receiver and an inertial measurement unit. The resulting algorithm is used to estimate position, velocity, and orientation of a maneuvering airplane and is evaluated against an accurate reference trajectory. A detailed study of the influence of the horizon length on the quality of the solution is presented and evaluated against filter-like and batch solutions of the problem. The versatile configuration possibilities of the framework are finally used to analyze the estimated solutions at different evaluation times exposing a nearly linear behavior of the sensor fusion problem. PMID:28534857

  2. A Comparative Study on the Suitability of Smartphones and IMU for Mobile, Unsupervised Energy Expenditure Calculi.

    Science.gov (United States)

    Ruiz-Zafra, Angel; Orantes-González, Eva; Noguera, Manuel; Benghazi, Kawtar; Heredia-Jimenez, Jose

    2015-07-27

    The metabolic equivalent of task (MET) is currently the most used indicator for measuring the energy expenditure (EE) of a physical activity (PA) and has become an important measure for determining and supervising a person's state of health. The use of new devices which are capable of measuring inertial movements by means of built-in accelerometers enable the PA to be measured objectively on the basis of the reckoning of "counts". These devices are also known as inertial measurement units (IMUs) and each count is an aggregated value indicating the intensity of a movement and can be used in conjunction with other parameters to determine the MET rate of a particular physical activity and thus it's associated EE. Various types of inertial devices currently exist that enable count calculus and physical activity to be monitored. The advent of mobile devices, such as smartphones, with empowered computation capabilities and integrated inertial sensors, has enabled EE to be measure in a distributed, ubiquitous and natural way, thereby overcoming the reluctance of users and practitioners associated with in-lab studies. From the point of view of the process analysis and infrastructure needed to manage data from inertial devices, there are also various differences in count computing: extra devices are required, out-of-device processing, etc. This paper presents a study to discover whether the estimation of energy expenditure is dependent on the accelerometer of the device used in measurements and to discover the suitability of each device for performing certain physical activities. In order to achieve this objective, we have conducted several experiments with different subjects on the basis of the performance of various daily activities with different smartphones and IMUs.

  3. A Comparative Study on the Suitability of Smartphones and IMU for Mobile, Unsupervised Energy Expenditure Calculi

    Directory of Open Access Journals (Sweden)

    Angel Ruiz-Zafra

    2015-07-01

    Full Text Available The metabolic equivalent of task (MET is currently the most used indicator for measuring the energy expenditure (EE of a physical activity (PA and has become an important measure for determining and supervising a person’s state of health. The use of new devices which are capable of measuring inertial movements by means of built-in accelerometers enable the PA to be measured objectively on the basis of the reckoning of “counts”. These devices are also known as inertial measurement units (IMUs and each count is an aggregated value indicating the intensity of a movement and can be used in conjunction with other parameters to determine the MET rate of a particular physical activity and thus it’s associated EE. Various types of inertial devices currently exist that enable count calculus and physical activity to be monitored. The advent of mobile devices, such as smartphones, with empowered computation capabilities and integrated inertial sensors, has enabled EE to be measure in a distributed, ubiquitous and natural way, thereby overcoming the reluctance of users and practitioners associated with in-lab studies. From the point of view of the process analysis and infrastructure needed to manage data from inertial devices, there are also various differences in count computing: extra devices are required, out-of-device processing, etc. This paper presents a study to discover whether the estimation of energy expenditure is dependent on the accelerometer of the device used in measurements and to discover the suitability of each device for performing certain physical activities. In order to achieve this objective, we have conducted several experiments with different subjects on the basis of the performance of various daily activities with different smartphones and IMUs.

  4. Calibration method of IMU on airborne POS%机载POS系统中惯性测量单元精度检校方法

    Institute of Scientific and Technical Information of China (English)

    曲直; 卢秀山; 左建章; 马东洋

    2011-01-01

    本文简要介绍了GPS/INS组合技术的优势和特点,分析了惯性测量单元(IMU)的工作原理及精度影响因素,系统阐述了机载POS系统中IMU的检校方法和精度评定方法,包括初始对准重复性检测、跟踪姿态角精度的标定和静态漂移检测等,并利用双轴数控转台,对3台不同类型的国产POS系统进行了数据采集、处理和对比分析,实验初步表明,本文提出的POS精度检校方法是可行的.%This paper briefly described the advantages and characteristics* of GPS/INS technique and the theory about POS, and In troduced the calibration methods for the IMU of Airborne POS, which included repetitive testing of initial alignment , tracking lealing and static drift three aspects systematically. Il used three different POS to collect data and did experiments for the detailed comparison, analy sis and research, and their accuracy assess, finally it explained the feasibility of the three methods used for POS system calibration.

  5. Cervical Coupling Motion Characteristics in Healthy People Using a Wireless Inertial Measurement Unit

    Directory of Open Access Journals (Sweden)

    Hyunho Kim

    2013-01-01

    Full Text Available Objective. The objectives were to show the feasibility of a wireless microelectromechanical system inertial measurement unit (MEMS-IMU to assess the time-domain characteristics of cervical motion that are clinically useful to evaluate cervical spine movement. Methods. Cervical spine movements were measured in 18 subjects with wireless IMUs. All rotation data are presented in the Euler angle system. Amount of coupling motions was evaluated by calculating the average angle ratio and the maximum angle ratio of the coupling motion to the primary motion. Reliability is presented with intraclass correlation coefficients (ICC. Results. Entire time-domain characteristics of cervical motion were measured with developed MEMS-IMU system. Cervical range of motion (CROM and coupling motion range were measured with high ICCs. The acquired data and calculated parameters had similar tendency with the previous studies. Conclusions. We evaluated cervical motion with economic system using a wireless IMU of high reliability. We could directly measure the three-dimensional cervical motion in degrees in realtime. The characteristics measured by this system may provide a diagnostic basis for structural or functional dysfunction of cervical spine. This system is also useful to demonstrate the effectiveness of any intervention such as conventional medical treatment, and Korean medical treatment, exercise therapy.

  6. Evaluation Method for Strap-down Inertial Navigation System of Multi-level Based on Gray Comprehensive Evaluation Model%基于灰色多层次综合评价模型的捷联惯性导航系统评估方法

    Institute of Scientific and Technical Information of China (English)

    石钊铭; 王文革

    2014-01-01

    The structure is complex and influence factors are too many to evaluate the performance of the strap down inertial navigation system by use of single index. Aimed at the problem, this paper puts forward an evaluation method of strap-down inertial navigation system based on multi-level gray comprehensive evaluation model. Firstly, in view of ship application, evaluation index system of the strap-down inertial navigation system is built. Then according to the structure characteristics of the strap-down inertial navigation system, the grey multi hierarchical comprehensive evaluation model is applied to the strap-down inertial navigation system. Finally, the effectiveness of the method is proved by use of simulation experiments.%针对捷联惯性导航系统层次结构复杂、影响因素较多、单一指标难以全面准确评估其综合性能的问题,提出了基于灰色多层次综合评价模型的捷联惯性导航系统评估方法。首先从舰船使用角度出发,构建了捷联惯性导航系统的评价指标体系,然后根据捷联惯性导航系统的结构特点,将灰色多层次综合评估模型应用于捷联惯性导航系统的评估中,最后仿真试验证明了方法的有效性。

  7. Strap-Down Inertial Systems

    Science.gov (United States)

    1978-05-01

    ua blas drift uffects. Due t• Itil Azimuth Error 8 #0 cas X BI WE 4 Where •.,.,,. 800is the rot sum of 8*0o G)80 8*01%t ý3 t hea uth erro~r f-uMtig...decrie th whle rogam. nc oter tsksmus be olvd qasi 0 WO 1000 40 20000 2400 3000 3453 IO Cm "a, Control Low Mechonicol- Diagnostic Table I~~ ArmO4 (*)o

  8. OPTIMIZED STRAPDOWN CONING CORRECTION ALGORITHM

    Institute of Scientific and Technical Information of China (English)

    黄磊; 刘建业; 曾庆化

    2013-01-01

    Traditional coning algorithms are based on the first-order coning correction reference model .Usually they reduce the algorithm error of coning axis (z) by increasing the sample numbers in one iteration interval .But the increase of sample numbers requires the faster output rates of sensors .Therefore ,the algorithms are often lim-ited in practical use .Moreover ,the noncommutivity error of rotation usually exists on all three axes and the in-crease of sample numbers has little positive effect on reducing the algorithm errors of orthogonal axes (x ,y) . Considering the errors of orthogonal axes cannot be neglected in the high-precision applications ,a coning algorithm with an additional second-order coning correction term is developed to further improve the performance of coning algorithm .Compared with the traditional algorithms ,the new second-order coning algorithm can effectively reduce the algorithm error without increasing the sample numbers .Theoretical analyses validate that in a coning environ-ment with low frequency ,the new algorithm has the better performance than the traditional time-series and fre-quency-series coning algorithms ,while in a maneuver environment the new algorithm has the same order accuracy as the traditional time-series and frequency-series algorithms .Finally ,the practical feasibility of the new coning al-gorithm is demonstrated by digital simulations and practical turntable tests .

  9. Initial Realization of a Sensor Fusion Based Onboard Maritime Integrated PNT Unit

    Directory of Open Access Journals (Sweden)

    Ralf Ziebold

    2013-03-01

    Full Text Available This paper introduces the basic concept of the Position Navigation and Timing (PNT Module as future part of a ship side Integrated Navigation System (INS. Core of the PNT Module is a sensor fusion based processing system (PNT Unit. The paper will focus on important aspects and first results of the initial practical realization of such a PNT Unit, including a realization of a Consistent Common Reference System (CCRS, GNSS/IMU tightly coupled positioning results as well as contingency performance of the inertial sensors.

  10. 方位捷联平台重力仪分布式Kalman滤波初始对准算法%Distributed Kalman filter initial alignment algorithm for azimuth strapdown platform gravimeter

    Institute of Scientific and Technical Information of China (English)

    杨晔; 毋兴涛; 杨建林; 高巍; 裴志

    2014-01-01

    为充分利用分布式架构重力仪各处理器并行计算的能力,解决单个处理器运行整体式 Kalman滤波所遇到的非实时性问题,设计了一种分布式 Kalman 滤波对准算法。首先,给出了方位捷联平台重力仪的误差方程,建立了系统的状态方程和观测方程。然后,用协方差分析法对系统初始对准滤波方程进行处理,将原系统分解成维数相同的两个子系统,得到由两个子滤波器构成的初始对准滤波器。最后,利用Matlab建立了方位捷联平台惯导模型,分别应用整体式滤波和分布式滤波进行静基座初始对准。仿真结果表明,分布式滤波算法与整体式滤波算法具有相同的滤波精度,并且分布式滤波用时只有整体式滤波的60%,更有利于保证滤波算法的实时性。%A distributed Kalman filter alignment algorithm is developed in order to use the parallel computing ability of the distributed architecture gravimeter to solve the non real-time implementation of filtering based on one single processor. Firstly, the error equations of the azimuth strapdown platform gravimeter are deduced, and the state equations and observation equations are built. Secondly, an error covariance analytical method is applied to the filtering equations, and the system is decentralised into two subsystems with the same dimension. In this way we get the initial alignment filter formed by the two subfilters. Finally, the azimuth strapdown platform model is built by using Matlab, and stationary base alignment is implemented by using global Kalman filter and distributed Kalman filter separately. The simulation results show that the distributed filter has the same filtering accuracy and costs only 60%of time compared with the global one, which is favorable to ensure the real-time performance of the algorithm.

  11. Inertial measurement unit using rotatable MEMS sensors

    Energy Technology Data Exchange (ETDEWEB)

    Kohler, Stewart M.; Allen, James J.

    2006-06-27

    A MEM inertial sensor (e.g. accelerometer, gyroscope) having integral rotational means for providing static and dynamic bias compensation is disclosed. A bias compensated MEM inertial sensor is described comprising a MEM inertial sense element disposed on a rotatable MEM stage. A MEM actuator for drives the rotation of the stage between at least two predetermined rotational positions. Measuring and comparing the output of the MEM inertial sensor in the at least two rotational positions allows, for both static and dynamic bias compensation in inertial calculations based on the sensor's output. An inertial measurement unit (IMU) comprising a plurality of independently rotatable MEM inertial sensors and methods for making bias compensated inertial measurements are disclosed.

  12. Inertial measurement unit using rotatable MEMS sensors

    Energy Technology Data Exchange (ETDEWEB)

    Kohler, Stewart M. (Albuquerque, NM); Allen, James J. (Albuquerque, NM)

    2007-05-01

    A MEM inertial sensor (e.g. accelerometer, gyroscope) having integral rotational means for providing static and dynamic bias compensation is disclosed. A bias compensated MEM inertial sensor is described comprising a MEM inertial sense element disposed on a rotatable MEM stage. A MEM actuator drives the rotation of the stage between at least two predetermined rotational positions. Measuring and comparing the output of the MEM inertial sensor in the at least two rotational positions allows for both static and dynamic bias compensation in inertial calculations based on the sensor's output. An inertial measurement unit (IMU) comprising a plurality of independently rotatable MEM inertial sensors and methods for making bias compensated inertial measurements are disclosed.

  13. Inertial measurement unit using rotatable MEMS sensors

    Science.gov (United States)

    Kohler, Stewart M.; Allen, James J.

    2007-05-01

    A MEM inertial sensor (e.g. accelerometer, gyroscope) having integral rotational means for providing static and dynamic bias compensation is disclosed. A bias compensated MEM inertial sensor is described comprising a MEM inertial sense element disposed on a rotatable MEM stage. A MEM actuator drives the rotation of the stage between at least two predetermined rotational positions. Measuring and comparing the output of the MEM inertial sensor in the at least two rotational positions allows for both static and dynamic bias compensation in inertial calculations based on the sensor's output. An inertial measurement unit (IMU) comprising a plurality of independently rotatable MEM inertial sensors and methods for making bias compensated inertial measurements are disclosed.

  14. 长航时捷联惯导重力扰动影响及补偿%Analysis and compensation of disturbing gravity effect on long-endurance ;strap-down inertial navigation system

    Institute of Scientific and Technical Information of China (English)

    丛琳; 赵忠; 杨小步

    2014-01-01

    The effect of disturbing gravity vector on Strap-down Inertial Navigation System(SINS)errors is analyzed from the navigation calculation aspects. Then disturbing gravity model is established using the non-uniform B-spline least squares technology which can compensate for SINS. Simulation results show that the gravity modeling method has good precision, and the compensation for long-endurance SINS based on gravity model can reduce the SINS errors effectively.%从捷联惯导系统导航解算出发,分析了重力扰动矢量对捷联惯导误差的影响,并根据非均匀B样条最小二乘法,对局部区域内的重力扰动进行二维逼近,建立重力扰动模型,进而对捷联惯导系统进行补偿。仿真结果表明,非均匀B样条建模方法具有很好的精度,利用建立的重力扰动模型对长航时捷联惯导进行补偿可以有效地减小惯导误差。

  15. 病态理论在捷联惯性导航粗对准中的应用%Application of Ill-Conditioned Matrix Theory in Coarse Alignment of Strapdown Inertial Navigation System

    Institute of Scientific and Technical Information of China (English)

    袁涛; 李四海; 徐景硕; 殷磊

    2011-01-01

    Aimed at coarse alignment of Strapdown Inertial Navigation System (SINS), the theory of reference vectors based on gravity vector has a problem of collinearity because the alignment time is transitory and the angle of gravity vectors turning in inertial space is little. The condition of ill-conditioned matrix theory was used to study the problem, the effect of alignment time on collinearity was confirmed. The simulation results show that the problem can be ignored after 1 minute, and the coarse lignment can be finished.%针对捷联惯性导航系统粗对准算法中存在共线性的问题,通过分析基于重力矢量信息的双矢量定姿对准算法中系数矩阵的病态性.利用病态矩阵理论中条件数方法对该问题进行分析研究,确定对准时间对共线性问题的影响,并以实例进行仿真计算.仿真结果表明,1 min后共线性问题可以忽略,可解决传统解析粗对准中的角运动干扰问题.

  16. 激光扫描仪结合GPS/IMU在地面三维形状测量中的应用%Use of laser scanner combining GPS/IMU on 3 DM shpae surveying on ground

    Institute of Scientific and Technical Information of China (English)

    林世祥

    2006-01-01

    阐述了开发使用比全站仪更为灵活的车载GPS/IMU(全球定位系统/惯性导航系统)结合地面型三维激光扫描仪,在地面三维形状测量的应用,并就系统构成,数据解析、检证、量测精度等进行了探讨.

  17. 捷联式旋转导向井斜方位动态解算方法%Dynamic solution approach to inclination and azimuth of strap-down rotary steerable system

    Institute of Scientific and Technical Information of China (English)

    薛启龙; 王瑞和; 孙峰; 韩来聚; 倪红坚

    2012-01-01

    According to strap-down vertical drilling field test, the playback analysis on underground storage of the measurement system was curried out. A dynamic resolution approach to inclination and azimuth of strap-down rotary steerable system was proposed, that is, with non rotating string, filtered real time signals on three-axis was all used for calculation, al the same time, filtered signals on x-axis, y-axis were stored. On the condition of rotation string, real time filtered signals on x-axis and stored signals of x-axis, y-axis with non-rotating string were adopted. In addition, stick-slip state of the downhole drilling tools was seen as a non-rotating "stationary" state. Real-time judgement method of string rotation state based on downhole survey data was proposed, and solution equation and dynamic solution process of deviation azimuth were given. And simulation in Matlab was done. The results show that the drill string vibration caused by rotation is the main reason for measurement error of deviation azimuth. The recommended dynamic survey approach could effectively enhance measurement precision, and deduce the effect of vibration on resolving results.%针对捷联式垂直钻井现场试验,对测量系统井下存储数据进行回放分析,提出捷联式旋转导向井斜方位动态解算方法,即在钻柱不旋转的情况下同时采用三轴实时滤波信号计算井斜方位并存储滤波后的x、y轴信号,在钻柱旋转的情况下采用滤波后的实时z轴信号,不旋转情况下采用存储的x、y轴信号进行计算.将井下钻具的黏滑状态也看作是一种不旋转的“静止”状态,提出利用井下测量数据实时判断钻柱旋转状态的方法,给出井斜方位角解算公式以及动态解算方法流程,并在Matlab软件中编制程序进行仿真验证.结果表明:钻柱旋转过程中的振动是引起井斜方位测量误差的主要原因;所提出的动态测量算法能够有效提高测量精度,减少钻

  18. 振动条件下激光陀螺捷联惯导系统的圆锥算法研究%Coning algorithm of laser gyro strapdown inertial navigation system in vibrating condition

    Institute of Scientific and Technical Information of China (English)

    钟明飞; 汤建勋; 江奇渊; 韩松来; 饶谷音; 袁保伦

    2014-01-01

    分析了振动条件下导弹捷联惯导系统(SINS)圆锥运动形成的原因,研究了经典圆锥运动补偿算法及其估计算法漂移的局限性。针对经典算法存在的局限性以及导弹等武器系统所处振动环境的特点,对标准圆锥补偿算法进行了优化。提出了振动条件下,在保证不影响导航计算机正常工作的前提下,圆锥运动补偿时有效利用前一周期姿态值的优化算法是有必要的。仿真和试验结果表明,在振动条件下,在进行圆锥运动补偿时应当采用标准优化圆锥运动补偿算法。%The cause that how the coning motion of missile strapdown inertial navigation system(SINS) in vibrating condition occurs was analyzed, and the classical coning compensation algorithm was studied. The limitation of classical compensation algorithm drifting error was also estimated. In the view the limitations of classical compensation algorithm and the characteristics of the vibrating environment of missiles and other weapons, the standard compensation algorithm were optimized. It was proposed that in vibrating condition, under the condition of not effecting the navigation computer′ s normal work, it is necessary to consider the pre-sample in the coning motion compensation. Simulation and experiment results show that the coning motion compensation should take the standard compensation algorithm in vibrating condition.

  19. An Adaptive Low-Cost GNSS/MEMS-IMU Tightly-Coupled Integration System with Aiding Measurement in a GNSS Signal-Challenged Environment.

    Science.gov (United States)

    Zhou, Qifan; Zhang, Hai; Li, You; Li, Zheng

    2015-09-18

    The main aim of this paper is to develop a low-cost GNSS/MEMS-IMU tightly-coupled integration system with aiding information that can provide reliable position solutions when the GNSS signal is challenged such that less than four satellites are visible in a harsh environment. To achieve this goal, we introduce an adaptive tightly-coupled integration system with height and heading aiding (ATCA). This approach adopts a novel redundant measurement noise estimation method for an adaptive Kalman filter application and also augments external measurements in the filter to aid the position solutions, as well as uses different filters to deal with various situations. On the one hand, the adaptive Kalman filter makes use of the redundant measurement system's difference sequence to estimate and tune noise variance instead of employing a traditional innovation sequence to avoid coupling with the state vector error. On the other hand, this method uses the external height and heading angle as auxiliary references and establishes a model for the measurement equation in the filter. In the meantime, it also changes the effective filter online based on the number of tracked satellites. These measures have increasingly enhanced the position constraints and the system observability, improved the computational efficiency and have led to a good result. Both simulated and practical experiments have been carried out, and the results demonstrate that the proposed method is effective at limiting the system errors when there are less than four visible satellites, providing a satisfactory navigation solution.

  20. An Adaptive Low-Cost GNSS/MEMS-IMU Tightly-Coupled Integration System with Aiding Measurement in a GNSS Signal-Challenged Environment

    Directory of Open Access Journals (Sweden)

    Qifan Zhou

    2015-09-01

    Full Text Available The main aim of this paper is to develop a low-cost GNSS/MEMS-IMU tightly-coupled integration system with aiding information that can provide reliable position solutions when the GNSS signal is challenged such that less than four satellites are visible in a harsh environment. To achieve this goal, we introduce an adaptive tightly-coupled integration system with height and heading aiding (ATCA. This approach adopts a novel redundant measurement noise estimation method for an adaptive Kalman filter application and also augments external measurements in the filter to aid the position solutions, as well as uses different filters to deal with various situations. On the one hand, the adaptive Kalman filter makes use of the redundant measurement system’s difference sequence to estimate and tune noise variance instead of employing a traditional innovation sequence to avoid coupling with the state vector error. On the other hand, this method uses the external height and heading angle as auxiliary references and establishes a model for the measurement equation in the filter. In the meantime, it also changes the effective filter online based on the number of tracked satellites. These measures have increasingly enhanced the position constraints and the system observability, improved the computational efficiency and have led to a good result. Both simulated and practical experiments have been carried out, and the results demonstrate that the proposed method is effective at limiting the system errors when there are less than four visible satellites, providing a satisfactory navigation solution.

  1. APPLYING 3D AFFINE TRANSFORMATION AND LEAST SQUARES MATCHING FOR AIRBORNE LASER SCANNING STRIPS ADJUSTMENT WITHOUT GNSS/IMU TRAJECTORY DATA

    Directory of Open Access Journals (Sweden)

    C. Ressl

    2012-09-01

    Full Text Available In this article we extend our previous work on the topic of ALS strip adjustment without GNSS/IMU trajectory data. Between overlap- ping strip pairs the relative orientation as a 3D affine transformation is estimated by a 3D LSM approach, which uses interpolated 2.5D grid surface models of the strips and the entire strip overlap as one big LSM window. The LSM derived relative orientations of all strip pairs in the block together with their covariance matrices are then used simultaneously as observations in an adjustment following the Gauss-Helmert model. This way the exterior orientation of each strip is computed, which refers to a relative block system. If proper ground control data is given, then an absolute orientation of the block of strips can be computed by a final LSM run. In a small example consisting of 4 strips with ca. 70% overlap the improvement in the relative geometric accuracy is demonstrated by the decreasing óMAD of the height differences from 8.4cm (before to 1.6cm (after the strip adjustment.

  2. 带减振器机抖激光陀螺惯性测量单元标定方法研究%Research on Calibration Method for Dither RLGs Inertial Measurement Unit with Shock Absorbers

    Institute of Scientific and Technical Information of China (English)

    吴赛成; 秦石乔; 王省书; 胡春生

    2011-01-01

    Because of the deformation of shock absorbers, the dither RLGs imrtial measurement unit ( IMU) can not be c alilnated using a precise tuntable as attitude reference. This palper inimduces a new calibratim method RLGs, IMU, firstly, the RLGs were turned off and the IMU without absorbers was fastened on a pmeise turntabde to calibrate the error parmenters of accelerometers; then the shock absorbers were installed on IMU, peper designed a procedure for the ealibration of RIGs error parameters. Fttrther mores,aeeotding to the output error equation of the RLGs, a systematic calibration algorithm of the RLGs IMU was proposed based on a 21dimensional kalman filter using velocity errors as measurement vector. The simulation results indicate, that the novel calibration method can accurately identify RLGs scale,factor errors,drifts,misalignments,errors and accealerometers drifts. and the accuracy of this methodsatisfy the requirements of high precision. inertial navigation system.%由于减振器会产生形变,使得带减振器的机抖激光陀螺惯性测量单元(IMU)不能使用由精密转台提供姿态基准的标定方法进行标定.提出了一种带减振器的机抖激光陀螺IMU标定的新方法,该方法先将IMU固联在精密转台上,不启动陀螺,依靠转台提供姿态参考标定出加表各误差参数;在此基础上装上减振器,设计了IMU陀螺误差参数标定路径,根据陀螺误差输出方程,建立21维的Kalman滤波系统级标定算法,并利用导航解算的速度误差作为其观测量.仿真结果表明,该方法能有效地标定出带减振器的机抖激光陀螺IMU的陀螺标度因数、常值漂移、安装误差和加速度计常值漂移等误差参数,满足高精度惯导系统的标定需求.

  3. Inertial measurements units for assessment of the pattern of forward bending among blue-collar workers from the DPhacto cohort

    DEFF Research Database (Denmark)

    Villumsen, Morten; Madeleine, Pascal; Jørgensen, Marie Birk

    2016-01-01

    Background. New developments in electronics have enabled the use of Inertial Measurement Units (IMUs) to record physical activity in a minimally obstructive manner over several days. Individual, physical and psychosocial risk factors are known to play a role in the development of work...... of the trunk were extracted from all-day IMU recordings, both at work and during leisure time. Exposure variation analysis was applied on forward bending during both work and leisure time.Low-back pain intensity was measured on a 0–10 scale and divided into low and high pain. Individual factors (age, gender...

  4. 基于IMU数据与双星定位系统组合的机载SAR运动补偿%Airborne SAR Motion Compensation Based on IMU Data and GEOSTAR Integrated System

    Institute of Scientific and Technical Information of China (English)

    郭振永; 邓云凯; 涂国防

    2007-01-01

    该文主要介绍了机载SAR平台运动误差中惯性测量单元(IMU)系统误差的补偿方法.由于双星定位系统误差不随时间递增,该文利用双星定位系统(GEOSTAR)与IMU进行组合,消除随时间递增的IMU系统误差,提高IMU定位精度,从而减轻SAR成像处理器运动补偿的负担.

  5. Application of time series modeling in initial alignment of strapdown fiber optic gyro (FOG) compass system%时间序列建模在光纤捷联罗经系统初始对准中的应用

    Institute of Scientific and Technical Information of China (English)

    王珏; 宋镜明; 李治民; 晁代宏

    2013-01-01

    Fiber Optic Gyro (FOG) random errors seriously affect the initial alignment accuracy of strapdown FOG compass system. In order to minimize FOG random error, a method for time sequence modeling of FOG random drift was presented, and Kalman filter was built. In the process of modeling, statistical test and corresponding pretreatment of FOG drift was essential, as the estimation procedures were available only for stable, normal and zero- mean series. Model was selected by judging the characteristic of "tail off" and "cut off", and the order was determined by final prediction error (FPE) criterion. Burg algorithm based on Levinson constraints was adopted to solve the model parameters. Based on Auto Regressive Moving Average (ARMA) model, system equations and observations were established, and Kalman Filter was carried out. The experimental result shows that Kalman Filter, which bases on AR (3) model, can effectively eliminate random errors. Not only the method improves the alignment accuracy, but also shortened the alignment time.%光纤陀螺(FOG)随机漂移严重影响捷联罗经系统初始对准的精度。通过对陀螺随机漂移进行建模,然后设计合适的卡尔曼滤波器进行滤波,可以减少随机漂移。在建模过程中,首先要对光纤陀螺随机漂移数据进行平稳性,正态性和零均值检验,之后进行数据预处理。通过相关函数的特点“拖尾”或者“截尾”来进行模型识别,采用最终输出误差准则选择模型的最佳阶数,然后采取Levison关系约束的Burg算法求解模型参数。根据模型建立系统方程和观测方程,然后进行卡尔曼滤波。实验结果表明,基于AR(3)模型的卡尔曼滤波可以有效的减少随机误差。这种方法不仅可以提高初始对准精度,也可以缩短对准时间。

  6. 机载激光捷联惯导系统动态误差的影响分析%Dynamic error effect analysis of airborne laser strap-down inertial navigation system

    Institute of Scientific and Technical Information of China (English)

    张卫侠; 张立峰; 刘中平; 钱渊

    2014-01-01

    激光捷联惯导系统中传感器由于直接与载体固联,同时还存在激光陀螺抖动振动,使系统误差特性较平台式系统更复杂,振动对系统动态误差影响更大。针对某型激光惯导系统随载机试飞中长航时精度超差的问题,分析了振动诱导误差的形成机理,查明了长航时精度超差的原因是由于惯导部件与其安装支架连接后的产品谐振频率与飞机螺旋桨叶通过频率耦合所致,为此提出了降低惯导部件内减振器带宽、提高载机惯导部件安装支架刚度的改进措施。经完善激光惯导系统算法,实施改进措施后,试飞考核,系统精度达标,从而验证了措施的正确性。%In laser strap-down inertial navigation system, the sensor is directly connected to carrierand the laser gyro has dither and vibration, so the system error properties become more complex and the vibration has a larger influence on system dynamic error compared with the platform type system.Aiming at the long-endurance out-of-precision-tolerance of a certain laser inertial navigation system of an aircraft during flight test, this article analyzes the formation mechanism of vibration induction error, finds out that long-endurance out-of-precision-tolerance is caused by the coupling of resonant frequency from the product formed by connecting inertial navigation component with its mount support and aircraft propeller blade frequency, and put forward the corrective measures: reducing the band width of vibration absorber in inertial navigation component and improving the mount support rigidity of aircraft inertial navigation component. After perfecting laser inertial navigation system algorithm, taking the corrective measures and testing flight, the system precision meets the requirement, which validates the correctness of the measures.

  7. Design of Guidance and Attitude Autopilot for Strap-down Guided Projectile%捷联制导弹药制导与控制系统设计与仿真∗

    Institute of Scientific and Technical Information of China (English)

    毛宁; 陈彦; 范世鹏; 林德福

    2015-01-01

    根据单兵武器捷联导引头的特点,提出一种弹体追踪和比例导引相结合的制导律。利用导引头的误差角信号和姿态陀螺的姿态信号,通过微分网络提取弹目视线角速率,实现比例导引部分,误差角信号作为姿态驾驶仪的输入完成弹体追踪部分。其次,利用根轨迹方法给出一种姿态驾驶仪设计方法。通过数学仿真可以证明,该制导律和姿态驾驶仪相结合,可实现精确命中目标,并具有良好的动态特性。最后,为论证MEMS陀螺和惯性陀螺等实现姿态驾驶仪的可行性,提出半实物仿真试验方案,作为理论设计进一步的验证手段。%According to characteristic of strap-down seeker for individual weapon, a guidance law combing proportional guidance with body-tracking guidance was proposed. By using the error angle signal output of the seeker and the attitude signal from the posture gyro, the angu-lar rate of the line of sight was obtained through differential network. The proportional guidance and the projectile tracking guidance were completed with input of the angular rate and the error angle signal for the autopilot. Besides, an elucidated design method for the autopilot of root locus method was given and general feature of the autopilot were also analyzed. The rationality of the new guidance law and the de-sign method of the autopilot was verified through mathematical simulation. High hitting accuracy can be realized and good dynamic charac-teristic was gained. Finally, in order to demonstrate the feasibility of MEMS gyro and inertial gyro, a hardware-in-the-loop experimental scheme was presented for further demonstration of the design.

  8. Comparison of a standalone consumer grade smartphone with a specialist inertial measurement unit for quantification of movement symmetry in the trotting horse.

    Science.gov (United States)

    Pfau, T; Weller, R

    2017-01-01

    Equine inertial measurement unit (IMU) gait analysis has gained in popularity for use in horses. Similar transducers are now found in consumer grade smartphones. However, to date there are no scientific data evaluating their use for assessment of movement (a)symmetry in the horse. To establish limits of agreement (LoA, mean difference ±2 s.d.) between a validated specialist IMU system and IMU data collected with a consumer grade smartphone for quantification of movement symmetry and range of motion (ROM) of pelvic movement in the trotting horse. Method comparison study based on quantitative gait data. Twenty horses were equipped with a specialist IMU (MTw, Xsens) and a consumer grade smartphone (Apple iPhone6), both securely attached immediately in front of one another in the midline over the sacrum. Horses were trotted in-hand and lunged on both reins on a soft arena surface. Median values for movement symmetry and ROM were determined over a series of strides for each exercise condition. Data collection was repeated in 6 horses to determine the effect of mediolateral sensor positioning on outcome parameters. Valid data from 17 horses resulted in LoA values of -3.7 ± 9.2 mm for MinDiff (difference between left and right hind mid stance), -0.6 ± 6.0 mm for MaxDiff (difference between left and right hind propulsion) and -0.8 ± 7.4 mm for ROM across horses and exercises. LoAs were narrower for straight line exercise and the negative bias was considerably reduced when moving the smartphone to the right of the midline. The consumer grade smartphone provided meaningful gait data in horses: LoAs in particular for in-hand exercise and when adjusting the mediolateral positioning are similar to published asymmetry thresholds. Owing to the sensitivity to mediolateral positioning, particular care should be taken when placing an IMU over the midline of the horse. © 2015 EVJ Ltd.

  9. A stationary north-finding scheme for an azimuth rotational IMU utilizing a linear state equality constraint.

    Science.gov (United States)

    Yu, Huapeng; Zhu, Hai; Gao, Dayuan; Yu, Meng; Wu, Wenqi

    2015-02-13

    The Kalman filter (KF) has always been used to improve north-finding performance under practical conditions. By analyzing the characteristics of the azimuth rotational inertial measurement unit (ARIMU) on a stationary base, a linear state equality constraint for the conventional KF used in the fine north-finding filtering phase is derived. Then, a constrained KF using the state equality constraint is proposed and studied in depth. Estimation behaviors of the concerned navigation errors when implementing the conventional KF scheme and the constrained KF scheme during stationary north-finding are investigated analytically by the stochastic observability approach, which can provide explicit formulations of the navigation errors with influencing variables. Finally, multiple practical experimental tests at a fixed position are done on a postulate system to compare the stationary north-finding performance of the two filtering schemes. In conclusion, this study has successfully extended the utilization of the stochastic observability approach for analytic descriptions of estimation behaviors of the concerned navigation errors, and the constrained KF scheme has demonstrated its superiority over the conventional KF scheme for ARIMU stationary north-finding both theoretically and practically.

  10. A Stationary North-Finding Scheme for an Azimuth Rotational IMU Utilizing a Linear State Equality Constraint

    Directory of Open Access Journals (Sweden)

    Huapeng Yu

    2015-02-01

    Full Text Available The Kalman filter (KF has always been used to improve north-finding performance under practical conditions. By analyzing the characteristics of the azimuth rotational inertial measurement unit (ARIMU on a stationary base, a linear state equality constraint for the conventional KF used in the fine north-finding filtering phase is derived. Then, a constrained KF using the state equality constraint is proposed and studied in depth. Estimation behaviors of the concerned navigation errors when implementing the conventional KF scheme and the constrained KF scheme during stationary north-finding are investigated analytically by the stochastic observability approach, which can provide explicit formulations of the navigation errors with influencing variables. Finally, multiple practical experimental tests at a fixed position are done on a postulate system to compare the stationary north-finding performance of the two filtering schemes. In conclusion, this study has successfully extended the utilization of the stochastic observability approach for analytic descriptions of estimation behaviors of the concerned navigation errors, and the constrained KF scheme has demonstrated its superiority over the conventional KF scheme for ARIMU stationary north-finding both theoretically and practically.

  11. Research and Analysis of Integrated Navigation System Based on D-GPS/IMU%基于D-GPS/IMU的组合导航方法研究与分析

    Institute of Scientific and Technical Information of China (English)

    陈柯; 魏学东; 祖肇梓

    2015-01-01

    研究了一种新的双GPS单元与IMU惯性测量单元组合结构(D-GPS/IMU)的导航应用问题;基于D-GPS/IMU的动力模型结构,分析了其状态空间的可观测性能,提出并证明了系统完全可观测的条件;同时,对扩展卡尔曼滤波(EKF)算法进行了改进,以定义的残差作为GPS量测信息中增益自适应调整的依据,并增加了数据反向区间平滑处理策略;最后,通过仿真实验,与基于EKF算法的单GPS与IMU组合结构(S-GPS/IMU)的姿态误差估计进行对比,实验结果表明,该方法收敛稳定且快、组合误差小,具有一定的实用性.

  12. Integrated Navigation System and Experiment of a Low-Cost and Low-Accuracy SINS/GPS%一种低成本低精度SINS/GPS组合导航系统及试验

    Institute of Scientific and Technical Information of China (English)

    林雪原; 徐进; 周旻

    2007-01-01

    When SINS (strap-down inertial navigation system) is combined with GPS, the observability of the course angle is weak. Although the course angle error is improved to some extent through Kalman filtering, the course angle still assumes a divergent trend. This trend is aggravated further when using low-cost and low-accuracy SINS. In order to restrain this trend, a method that uses AHRS to substitute for SINS course angle information is put forward aimed at the hardware component characteristic of the low-cost and low-accuracy SINS including AHRS (attitude and heading reference system) and IMU (inertial measurement unit). Real static and dynamic experiments show that the method can restrain the divergent trend of the navigation system angle effectively, and the positioning accuracy is high.

  13. A rotating inertial navigation system with the rotating axis error compensation consisting of fiber optic gyros

    Institute of Scientific and Technical Information of China (English)

    ZHA Feng; HU Bai-qing; QIN Fang-jun; LUO Yin-bo

    2012-01-01

    An effective and flexible rotation and compensation scheme is designed to improve the accuracy of rotating inertial navigation system (RINS).The accuracy of single-axial RINS is limited by the errors on the rotating axis.A novel inertial measurement unit (IMU) scheme with error compensation for the rotating axis of fiber optic gyros (FOG) RINS is presented.In the scheme,two couples of inertial sensors with similar error characteristics are mounted oppositely on the rotating axes to compensate the sensors error.Without any change for the rotation cycle,this scheme improves the system's precision and reliability,and also offers the redundancy for the system.The results of 36 h navigation simulation prove that the accuracy of the system is improved notably compared with normal strapdown INS,besides the heading accuracy is increased by 3 times compared with single-axial RINS,and the position accuracy is improved by 1 order of magnitude.

  14. Quantifying Stability Using Frequency Domain Data from Wireless Inertial Measurement Units

    Directory of Open Access Journals (Sweden)

    Stephen Slaughter

    2012-08-01

    Full Text Available The quantification of gait stability can provide valuable information when evaluating subjects for age related and neuromuscular disease changes. Using tri-axial inertial measurement units (IMU for acceleration and rotational data provide a non-linear profile for this type of movement. As subjects traverse various surfaces representing decreasing stability, the different phasing of gait data make comparisons difficult. By converting from time to frequency domain data, the phase effects can be ignored, allowing for significant correlations. In this study, 12 subjects provided gait information over various surfaces while wearing an IMU. Instabilities were determined by comparing frequency domain data over less stable surfaces to frequency domain data of neural network (NN models representing the normal gait for any given participant. Time dependent data from 2 axes of acceleration and 2 axes of rotation were converted using a discrete Fourier transform (FFT algorithm. The data over less stable surfaces were compared to the normal gait NN model by averaging the Pearson product moment correlation (r values. This provided a method to quantify the decreased stability. Data showed progressively decreasing correlation coefficient values as subjects encountered progressively less stable surface environments. This methodology has allowed for the quantification of instability in gait situations for application in real-time fall prevention situations.

  15. A Highly Miniaturized, Wireless Inertial Measurement Unit for Characterizing the Dynamics of Pitched Baseballs and Softballs

    Directory of Open Access Journals (Sweden)

    Noel C. Perkins

    2012-08-01

    Full Text Available Baseball and softball pitch types are distinguished by the path and speed of the ball which, in turn, are determined by the angular velocity of the ball and the velocity of the ball center at the instant of release from the pitcher’s hand. While radar guns and video-based motion capture (mocap resolve ball speed, they provide little information about how the angular velocity of the ball and the velocity of the ball center develop and change during the throwing motion. Moreover, mocap requires measurements in a controlled lab environment and by a skilled technician. This study addresses these shortcomings by introducing a highly miniaturized, wireless inertial measurement unit (IMU that is embedded in both baseballs and softballs. The resulting “ball-embedded” sensor resolves ball dynamics right on the field of play. Experimental results from ten pitches, five thrown by one softball pitcher and five by one baseball pitcher, demonstrate that this sensor technology can deduce the magnitude and direction of the ball’s velocity at release to within 4.6% of measurements made using standard mocap. Moreover, the IMU directly measures the angular velocity of the ball, which further enables the analysis of different pitch types.

  16. A novel approach to navigated implantation of S-2 alar iliac screws using inertial measurement units.

    Science.gov (United States)

    Jost, Gregory F; Walti, Jonas; Mariani, Luigi; Cattin, Philippe

    2016-03-01

    The authors report on a novel method of intraoperative navigation with inertial measurement units (IMUs) for implantation of S-2 alar iliac (S2AI) screws in sacropelvic fixation of the human spine and its application in cadaveric specimens. Screw trajectories were planned on a multiplanar reconstruction of the preoperative CT scan. The pedicle finder and screwdriver were equipped with IMUs to guide the axial and sagittal tilt angles of the planned trajectory, and navigation software was developed. The entry points were chosen according to anatomical landmarks on the exposed spine. After referencing, the sagittal and axial orientation of the pedicle finder and screwdriver were wirelessly monitored on a computer screen and aligned with the preoperatively planned tilt angles to implant the S2AI screws. The technique was performed without any intraoperative imaging. Screw positions were analyzed on postoperative CT scans. Seventeen of 18 screws showed a good S2AI screw trajectory. Compared with the postoperatively measured tilt angles of the S2AI screws, the IMU readings on the screwdriver were within an axial plane deviation of 0° to 5° in 15 (83%) and 6° to 10° in 2 (11%) of the screws and within a sagittal plane deviation of 0° to 5° in 15 (83%) and 6° to 10° in 3 (17%) of the screws. IMU-based intraoperative navigation may facilitate accurate placement of S2AI screws.

  17. A Wearable Inertial Measurement Unit for Long-Term Monitoring in the Dependency Care Area

    Directory of Open Access Journals (Sweden)

    Andreu Català

    2013-10-01

    Full Text Available Human movement analysis is a field of wide interest since it enables the assessment of a large variety of variables related to quality of life. Human movement can be accurately evaluated through Inertial Measurement Units (IMU, which are wearable and comfortable devices with long battery life. The IMU’s movement signals might be, on the one hand, stored in a digital support, in which an analysis is performed a posteriori. On the other hand, the signal analysis might take place in the same IMU at the same time as the signal acquisition through online classifiers. The new sensor system presented in this paper is designed for both collecting movement signals and analyzing them in real-time. This system is a flexible platform useful for collecting data via a triaxial accelerometer, a gyroscope and a magnetometer, with the possibility to incorporate other information sources in real-time. A µSD card can store all inertial data and a Bluetooth module is able to send information to other external devices and receive data from other sources. The system presented is being used in the real-time detection and analysis of Parkinson’s disease symptoms, in gait analysis, and in a fall detection system.

  18. Analysis of the influence of launching platform navigation error on the strapdown inertial navigation system of anti ship missile%发射平台导航误差对反舰导弹捷联惯导系统影响分析

    Institute of Scientific and Technical Information of China (English)

    李曦

    2016-01-01

    建立动基座条件下反舰导弹捷联惯导系统误差传播方程,分析发射平台导航参数误差对导弹惯导定位误差的影响,得出了相关的结论。研究结果可以为武器试验鉴定工作提供支撑。%Based onthe error propagation equation of the strapdown inertial navigation system of the anti ship missile under the condition of moving base,the influence of the navigation parameters of the launching platform on the positioning error of missile inertial navigation system is analyzed, and the related conclusion is drawn.The results of the study can provide support for the weapon test and appraisal work.

  19. IMU/DGPS 辅助空三下几种布点方案的精度比较%Several Layout Point Projects Precision Compare in the IMU/DGPS Assisted Aerial Triangulation

    Institute of Scientific and Technical Information of China (English)

    荣幸

    2014-01-01

    This paper mainly introduced in the IMU/DGPS assisted aerial triangulation ,through the different layout point project to the aerial triangulation , compare and analysis these Achievements , what accuracy can we get that analysis for the POS assisted aerial triangulation at few control points or no control points .How can meet the requirements of whichmapping scale .%主要介绍了在IMU/DGPS辅助空三的情况下,通过对不同的布点方案进行空三加密,对这些空三成果进行精度比较与分析,分析POS辅助空三在无地面控制点或少量的地面控制点的情况下能获得怎样的精度,能满足多大比例尺的成图要求。

  20. 机载InSAR系统成像对DGPS/IMU要求分析%Requirement Analysis of DGPS/IMU for Air-Borne InSAR System's Imaging

    Institute of Scientific and Technical Information of China (English)

    楼良盛; 刘志铭; 周瑜

    2011-01-01

    The elevation is surveyed by the InSAR system through the phase difference of the two interference complex images, so the phase accuracy is one of the main factors that influences the system's elevation surveying accuracy. According to the principle of the InSAR imaging movement compensation, the position and velocity surveyed by DGPS/IMU will directly influence the accuracy of imaging movement compensation. On the basis of analyzing the influence of InSAR imaging movement compensation to the phase accuracy and phase accuracy to the elevation surveying accuracy, and according to the requirement of the phase accuracy in the InSAR system, the accuracy requirements of the DGPS/IMU in the InSAR imaging movement compensation were proposed.%InSAR系统根据两幅相干复影像的相位差进行高程测量,相位精度是影响系统高程测量精度的主要因素之一.依据InSAR成像运动补偿原理,DGPS/IMU测量的位置和速度精度将直接影响成像运动补偿精度.在分析了InSAR成像运动补偿对相位精度及相位精度对高程测量精度影响的基础上,根据InSAR系统对相位精度的要求,提出了InSAR成像运动补偿对DGPS/IMU精度要求.

  1. [RECALMIN. Patient care in the internal medicine units of the Spanish national health system].

    Science.gov (United States)

    Zapatero Gaviria, A; Barba Martín, R; Román Sánchez, P; Casariego Vales, E; Diez Manglano, J; García Cors, M; Jusdado Ruiz-Capillas, J J; Suárez Fernández, C; Bernal, J L; Elola Somoza, F J

    2016-05-01

    To perform a situation analysis of the care provided by internal medicine units (IMUs) in Spain and to develop, based on this analysis, proposals for improving the quality of care in these units. A descriptive, cross-sectional study of the IMUs of general acute care hospitals of the Spanish National Health System (SNHS), with data referring to 2013. The study variables were collected via an ad hoc questionnaire. Of the total 260hospitals identified in the SNHS, 142responses were obtained from 139hospitals throughout Spain, which represents 53.5% of the IMUs in the SNHS. The mean number of internists per IMU was 14±8, with a mean rate of 7.2±3.3 internists per 100,000 inhabitants. In 2013, the average number of hospital discharges from the IMU was 2,987±2,066, and those discharged by internists was 232±107. Sixty-one percent of the IMUs had implemented an interconsultation unit, and 41% had implemented a systematic care program for complex chronic patients. Thirty-three percent of the IMUs conducted multidisciplinary rounds, and 60% of these IMUs planned the discharge. The 2013 RECALMIN survey revealed a number of important aspects of the organisation, structure and management of IMUs. The remarkable variability in the indicators of structure, activity and management probably reflect significant differences in efficiency and productivity, which therefore provide significant room for improvement. Copyright © 2016 Elsevier España, S.L.U. y Sociedad Española de Medicina Interna (SEMI). All rights reserved.

  2. Multisensor robot navigation system

    Science.gov (United States)

    Persa, Stelian; Jonker, Pieter P.

    2002-02-01

    Almost all robot navigation systems work indoors. Outdoor robot navigation systems offer the potential for new application areas. The biggest single obstacle to building effective robot navigation systems is the lack of accurate wide-area sensors for trackers that report the locations and orientations of objects in an environment. Active (sensor-emitter) tracking technologies require powered-device installation, limiting their use to prepared areas that are relative free of natural or man-made interference sources. The hybrid tracker combines rate gyros and accelerometers with compass and tilt orientation sensor and DGPS system. Sensor distortions, delays and drift required compensation to achieve good results. The measurements from sensors are fused together to compensate for each other's limitations. Analysis and experimental results demonstrate the system effectiveness. The paper presents a field experiment for a low-cost strapdown-IMU (Inertial Measurement Unit)/DGPS combination, with data processing for the determination of 2-D components of position (trajectory), velocity and heading. In the present approach we have neglected earth rotation and gravity variations, because of the poor gyroscope sensitivities of our low-cost ISA (Inertial Sensor Assembly) and because of the relatively small area of the trajectory. The scope of this experiment was to test the feasibility of an integrated DGPS/IMU system of this type and to develop a field evaluation procedure for such a combination.

  3. Reliability of Wearable Inertial Measurement Units to Measure Physical Activity in Team Handball.

    Science.gov (United States)

    Luteberget, Live S; Holme, Benjamin R; Spencer, Matt

    2017-09-05

    The purpose of this study was to assess the reliability and sensitivity of commercially available inertial measurement units (IMU) to measure physical activity in team handball. Twenty-two handball players were instrumented with two IMUs (OptimEye S5, Catapult Sports, Australia) taped together. They participated in either a laboratory assessment (n=10), consisting of seven team handball specific tasks, or field assessment (n=12) conducted in twelve training sessions. Variables, including PlayerLoad™ and inertial movement analysis (IMA) magnitude and counts, were extracted from the manufactures software. IMA count was divided into intensity bands of low (1.5-2.5m·s(-1)), medium (2.5-3.5m·s(-1)), high (>3.5m·s(-1)), medium/high (>2.5m·s(-1)), and total (>1.5m·s(-1)). Reliability between devices and sensitivity was established using coefficient of variation (CV) and smallest worthwhile difference (SWD). Laboratory assessment : IMA magnitude showed a good reliability (CV: 3.1%) in well-controlled tasks. CV increased (4.4-6.7%) in more complex tasks. Field assessment : Total IMA count (CV: 1.8%, SWD: 2.5%), PlayerLoad™ (CV: 0.9 % SWD: 2.1%), and its associated variables (CV: 0.4-1.7%) showed a good reliability, well below the SWD. However, the CV of IMA increased when categorized into intensity bands (2.9-5.6%). The reliability of IMA count were good, when data was displayed as total, high or medium/high counts. A good reliability for PlayerLoad™ and associated variables was evident. The CV of the aforementioned variables was well below the SWD, suggesting that OptimEye IMU and its software are sensitive for use in team handball.

  4. A novel redundant INS based on triple rotary inertial measurement units

    Science.gov (United States)

    Chen, Gang; Li, Kui; Wang, Wei; Li, Peng

    2016-10-01

    Accuracy and reliability are two key performances of inertial navigation system (INS). Rotation modulation (RM) can attenuate the bias of inertial sensors and make it possible for INS to achieve higher navigation accuracy with lower-class sensors. Therefore, the conflict between the accuracy and cost of INS can be eased. Traditional system redundancy and recently researched sensor redundancy are two primary means to improve the reliability of INS. However, how to make the best use of the redundant information from redundant sensors hasn’t been studied adequately, especially in rotational INS. This paper proposed a novel triple rotary unit strapdown inertial navigation system (TRUSINS), which combines RM and sensor redundancy design to enhance the accuracy and reliability of rotational INS. Each rotary unit independently rotates to modulate the errors of two gyros and two accelerometers. Three units can provide double sets of measurements along all three axes of body frame to constitute a couple of INSs which make TRUSINS redundant. Experiments and simulations based on a prototype which is made up of six fiber-optic gyros with drift stability of 0.05° h-1 show that TRUSINS can achieve positioning accuracy of about 0.256 n mile h-1, which is ten times better than that of a normal non-rotational INS with the same level inertial sensors. The theoretical analysis and the experimental results show that due to the advantage of the innovative structure, the designed fault detection and isolation (FDI) strategy can tolerate six sensor faults at most, and is proved to be effective and practical. Therefore, TRUSINS is particularly suitable and highly beneficial for the applications where high accuracy and high reliability is required.

  5. Aerial vehicle navigation over unknown terrain environments using inertial measurements and dual airborne laser scanners or flash ladar

    Science.gov (United States)

    Vadlamani, Ananth K.; Uijt de Haag, Maarten

    2007-04-01

    A precise navigation system for uninhabited or inhabited aerial vehicles is discussed in this paper. The navigational capability of an aerial vehicle must be robust and not easily influenced by external factors. Nowadays, many navigation systems rely somehow on the Global Positioning System (GPS), wherein the GPS signals may be rendered unusable due to unintentional interference caused by atmospheric effects, interference from communication equipment, as well as intentional jamming. The navigation method discussed in this paper integrates measurements from an Inertial Measurement Unit (IMU) with measurements from either two airborne laser scanners (ALS) or an airborne Flash LADAR (AFL) to provide autonomous navigational capability and a reliable alternative to GPS. The proposed system has applications in unknown or partially known terrain environments or it may also be used for autonomous landing systems in Lunar or Martian environments. Two approaches are described in this paper, one approach uses Dual Airborne Laser Scanners (DALS) (one pointing forward, the other pointing aft) and the other approach uses an AFL. Advantages and disadvantages of both approaches are discussed. The proposed navigation system uses strapdown IMU measurements to estimate the aerial vehicle position and attitude and to geo-reference the laser sensor data. It then uses the maps created from both the fore and aftpointing scanning LADARS or the consecutive Flash LADAR range-images to estimate systematic IMU errors such as position and velocity drifts. The proposed navigation algorithm is evaluated using flight test data from Ohio University's DC3 aircraft and synthesized ALS and AFL measurements. Initial results are observed to achieve meter level accuracies in the system's position drift performance.

  6. Magnetic Shielding Method and Experiment Study of Inertial Measurement Unit Based on High Precision Fiber-optic Gyroscope%高精度光纤IMU的磁屏蔽方法及实验研究

    Institute of Scientific and Technical Information of China (English)

    李金涛; 房建成

    2011-01-01

    惯性测量单元(IMU)是位置姿态系统(POS)的核心部分,IMU的精度很大程度上决定着POS精度.由于高精度光纤陀螺(FOG)的光纤线圈对磁场敏感,基于高精度FOG的IMU精度会受磁场影响而降低.本文研究了FOG磁敏感性机理,通过实验得出高精度光纤IMU对磁场敏感的结论.采用电磁场有限元分析软件Ansoft Maxwell研究了磁屏蔽体采用不同材料、不同厚度时的磁屏蔽效能(SE),并进行了IMU磁屏蔽结构设计.通过亥姆霍兹线圈测试得到的磁屏蔽体实际屏蔽效能最高为48.20 dB,与有限元分析结果基本一致.转台环境测试表明:屏蔽体使FOG漂移减小到9%以上;亥姆霍兹线圈测试表明:通过磁屏蔽使FOG零偏磁敏感度衰减2~21 dB,漂移磁敏感度衰减9~23 dB,对提高光纤IMU测试和应用精度以及机载环境适应性有重要意义.%The inertial measurement unit (IMU) is the core of a position and orientation system (POS), whose accuracy has a crucial impact on POS accuracy. But the IMU accuracy based on high precision fiber-optic gyroscope (FOG) is degraded because of the sensitivity of the FOG fiber coil to the magnetic field. This paper studied the magnetic sensitivity mechanism of the FOG. And through experimental study reached the conclusion that the IMU based on a high precision FOG is also sensitive to the magnetic field. An IMU shielding is designed, and its shielding effectiveness (SE) is analyzed by electromagnetic field finite element analysis software Ansoft Maxwell for different materials with different thicknesses. The best SE of 48.20 Db is achieved with a Helmholtz coil test, which is consistent with the results of the finite element analysis. The turn table test shows that a reduction of over 9% of the FOG drift is achieved with the enclosure. The Helmholtz coil test with magnetic shielding demonstrates that the bias and drift magnetic sensitivity of the FOG are decreased by 2-21 Db and 9-23 Db

  7. Generating Units

    Data.gov (United States)

    Department of Homeland Security — Generating Units are any combination of physically connected generators, reactors, boilers, combustion turbines, and other prime movers operated together to produce...

  8. A Calibration and Error Analysis Method for IMU Using Centrifuge%惯性测量组件离心机标定及误差分析方法

    Institute of Scientific and Technical Information of China (English)

    赵剡; 张少辰; 胡涛

    2015-01-01

    针对传统惯性测量组件(IMU)标定方法不能根据加速度计测量量程提供足够大的信号激励,并且现有离心机标定方法未考虑IMU在离心机上的安装位置偏差的问题,提出了一种基于离心机的IMU标定及误差分析方法.将IMU按照6个基准位置安装于离心机上,通过离心机在水平面内旋转,为IMU提供角速度激励和加速度激励.通过对IMU的输出进行旋转积分,可以消除地球自转以及离心机不水平带来的谐波影响,获得IMU的输出方程.在不考虑IMU在离心机上安装的位置偏差角的情况下,采用线性最小二乘法求解;在考虑IMU偏差角的情况下,采用牛顿法求解,可以标定出IMU的标度因数、安装误差、零偏、IMU偏差角等共计27个误差系数.建立了标定方案中的离心机控制模型和误差传播模型,并对模型进行了仿真验证.仿真试验表明,该标定方法步骤简单,输入激励可调,标定结果误差可控.

  9. An Approach of Attitude Estimation by Using Vision-Aided IMU for Mars Rover%基于视觉和MEMS-IMU融合的火星车导航定向技术

    Institute of Scientific and Technical Information of China (English)

    娄路

    2012-01-01

    The autonomous navigation and attitude estimation is one of the most challenge tasks of planetary rover operations. The heading information is an important part of Mars rover navigation , and its precision will affect the localization precision and the performance of navigation directly, especially for long range and long duration travel on the Mars. In order to acquire the attitude and heading, the visual aided MEMS-IMU methods are presented, which use accelerometer to correct gyro biases and develop an appearance-based algorithm to measure heading/rotation with monocular camera. The methods are simple f realtime and reliable, and the experimental results demonstrate the effectiveness of the approach proposed.%火星探测车需要在复杂非结构化火星地表环境下完成自主导航定位任务.针对火星车导航定位传感器的低功耗、微型化的发展趋势,提出一种基于MEMS - IMU的传感器补偿融合、单目视觉航向测定的方法.该方法能克服火星复杂地表和单一性地貌环境可能导致的测试误差过大问题.模拟环境下的实验数据结果显示该方法具备实时性好、可靠性高的特点,姿态估计和航向测量的准确率较高.

  10. 惯性测量单元在老年人跌倒风险评估中的应用进展%Inertial Measurement Unit and Fall Risk Assessment in the Elderly (review)

    Institute of Scientific and Technical Information of China (English)

    杨波; 付成龙

    2015-01-01

    Falling in the elderly is a major health problem and may cause severe consequences. Fall risk assessment is important for pre-venting and intervening fall incidence. Inertial Measurement Unit (IMU) has been introduced to evaluate motion/balance function and fall risk among the older people. Some researches indicated that it might have advantages over the usual tools, and can be used in the hospitals, communities, nursing homes, etc. IMU is a good way to measure gait variability, which may be strongly related with the risk of falls.%跌倒是老年人群中常见且后果严重的公共卫生事件,跌倒风险评估是跌倒预防和干预的重要手段。国外研究者将惯性测量单元引入老年人运动/平衡功能测量和跌倒风险的评估。研究提示,它比常用的跌倒评估工具具有优势,可应用于医院、社区和养老机构等。惯性测量单元可能是测量步态变异性的良好方法,步态变异性与跌倒风险相关性很高。

  11. UNIT, TIBET.

    Science.gov (United States)

    Louisiana Arts and Science Center, Baton Rouge.

    THE UNIT OF STUDY DESCRIBED IN THIS BOOKLET DEALS WITH THE GEOGRAPHY AND HISTORY OF TIBET. THE UNIT COVERS SOME OF THE GENERAL FEATURES OF THE COUNTRY AND THEIR EFFECT UPON THE LIVES OF THE TIBETAN PEOPLE. DISCUSSION QUESTIONS ARE INSERTED TO STIMULATE THOUGHT. THE RELIGION OF TIBET IS DISCUSSED IN RELATION TO ITS INFLUENCE ON THE ART AND CULTURE…

  12. A pedestrian dead-reckoning system that considers the heel-strike and toe-off phases when using a foot-mounted IMU

    Science.gov (United States)

    Ju, Hojin; Lee, Min Su; Park, So Young; Song, Jin Woo; Park, Chan Gook

    2016-01-01

    In this paper, we propose an advanced pedestrian dead-reckoning (PDR) algorithm that considers the heel-strike and toe-off phases. Generally, PDR systems that use a foot-mounted inertial measurement unit are based on an inertial navigation system with an extended Kalman filter (EKF). To reduce the influence of the bias and white noises in the gyroscope and accelerometer signals, a zero-velocity update is often adopted at the stance phase. However, transient and large acceleration, which cannot be measured by the accelerometer used in pedestrian navigation, occur momentarily in the heel-strike phase. The velocity information from integration of the acceleration is not reliable because the acceleration is not measured in the heel-strike phase. Therefore, the designed EKF does not correctly reflect the actual environment, because conventional algorithms do not take the non-measurable acceleration into consideration. In order to reflect the actual environment, we propose a PDR system that considers the non-measurable acceleration from the heel-strike impact. To improve the PDR system’s performance, the proposed algorithm uses a new velocity measurement obtained using the constraint between the surface and the foot during the toe-off phase. The experimental results show improved filter performance after comparison of the proposed algorithm and a conventional algorithm.

  13. Turnley Unit

    Data.gov (United States)

    Federal Laboratory Consortium — Facilities at this unit include cattle working pens, hydraulic squeeze chute and electronic scale, a maintenance building, and four hay storage sheds. There is one...

  14. Operable Units

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset consists of operable unit data from multiple Superfund sites in U.S. EPA Region 8. These data were acquired from multiple sources at different times and...

  15. Detector Unit

    CERN Multimedia

    1960-01-01

    Original detector unit of the Instituut voor Kernfysisch Onderzoek (IKO) BOL project. This detector unit shows that silicon detectors for nuclear physics particle detection were already developed and in use in the 1960's in Amsterdam. Also the idea of putting 'strips' onto the silicon for high spatial resolution of a particle's impact on the detector were implemented in the BOL project which used 64 of these detector units. The IKO BOL project with its silicon particle detectors was designed, built and operated from 1965 to roughly 1977. Detector Unit of the BOL project: These detectors, notably the ‘checkerboard detector’, were developed during the years 1964-1968 in Amsterdam, The Netherlands, by the Natuurkundig Laboratorium of the N.V. Philips Gloeilampen Fabrieken. This was done in close collaboration with the Instituut voor Kernfysisch Onderzoek (IKO) where the read-out electronics for their use in the BOL Project was developed and produced.

  16. [Conservation Units.

    Science.gov (United States)

    Texas Education Agency, Austin.

    Each of the six instructional units deals with one aspect of conservation: forests, water, rangeland, minerals (petroleum), and soil. The area of the elementary school curriculum with which each correlates is indicated. Lists of general and specific objectives are followed by suggested teaching procedures, including ideas for introducing the…

  17. [Conservation Units.

    Science.gov (United States)

    Texas Education Agency, Austin.

    Instructional units deal with each aspect of conservation: forests, wildlife, rangelands, water, minerals, and soil. The area of the secondary school curriculum with which each is correlated is indicated. Lists of general and specific objectives are followed by suggested teaching procedures, including ideas for introducing the topic, questions to…

  18. FLYING UNITED

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Apart from selling hundreds of airplanes to China, Boeing buys locally made aircraft parts and transfers technology, in the true spirit of partnership Whenever Boeing's senior manager hear of a visit by one of China's state leaders, it's no doubt cause for celebration. Since China and the United States established diplomatic ties in 1978, every official trip by China's top statesmen has included a meeting with Boeing that

  19. Multiple IMU system development, volume 1

    Science.gov (United States)

    Landey, M.; Mckern, R.

    1974-01-01

    A redundant gimballed inertial system is described. System requirements and mechanization methods are defined and hardware and software development is described. Failure detection and isolation algorithms are presented and technology achievements described. Application of the system as a test tool for shuttle avionics concepts is outlined.

  20. 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...

  1. More on IMU Self-Alighment Techniques.

    Science.gov (United States)

    most efficient matrix inversion algorithm specially tailored for the parameter correlated least square regression algorithm, (2) sensitivity simulation...of the self-alignment accuracy with respect to data size and data section, (3) the correct choice of an analytic model for least square data...processing, and (4) the correct relationship between the way time is counted and the least square regression model.

  2. United States

    Directory of Open Access Journals (Sweden)

    Stephen Bernow

    1998-12-01

    Full Text Available This paper presents and discusses an integrated set of policies designed to reduce U.S. carbon emissions over the next four decades. This innovation path also aims to promote environmental quality, particularly by reducing emissions of criteria air pollutants, to reduce U.S. dependence on imported oil, and to induce technological innovation and diffusion in energy production and consumption. The innovation path would reduce economy-wide carbon emissions by 26% below baseline projections for 2010 and by 62% below baseline projections for 2030; this translates into 10% below 1990 levels in 2010 and 45% below 1990 levels in 2030. Emissions of criteria pollutants also would be significantly reduced, as would petroleum imports by the United States. Moreover, the innovation path would yield cumulative net savings for the United States of $218 billion (1993 dollars through 2010, or $19 billion on a leveled annual basis, and would result in 800,000 additional jobs nationwide by 2010. Although the overall findings from the innovation path analysis are robust, the results should be taken as indicative, rather than precisely predictive, owing to uncertainties in future costs, prices, technology performance, and consumer behavior.

  3. Automated pavement horizontal curve measurement methods based on inertial measurement unit and 3D profiling data

    Directory of Open Access Journals (Sweden)

    Wenting Luo

    2016-04-01

    Full Text Available Pavement horizontal curve is designed to serve as a transition between straight segments, and its presence may cause a series of driving-related safety issues to motorists and drivers. As is recognized that traditional methods for curve geometry investigation are time consuming, labor intensive, and inaccurate, this study attempts to develop a method that can automatically conduct horizontal curve identification and measurement at network level. The digital highway data vehicle (DHDV was utilized for data collection, in which three Euler angles, driving speed, and acceleration of survey vehicle were measured with an inertial measurement unit (IMU. The 3D profiling data used for cross slope calibration was obtained with PaveVision3D Ultra technology at 1 mm resolution. In this study, the curve identification was based on the variation of heading angle, and the curve radius was calculated with kinematic method, geometry method, and lateral acceleration method. In order to verify the accuracy of the three methods, the analysis of variance (ANOVA test was applied by using the control variable of curve radius measured by field test. Based on the measured curve radius, a curve safety analysis model was used to predict the crash rates and safe driving speeds at horizontal curves. Finally, a case study on 4.35 km road segment demonstrated that the proposed method could efficiently conduct network level analysis.

  4. RECALMIN: The association between management of Spanish National Health Service Internal Medical Units and health outcomes.

    Science.gov (United States)

    Zapatero-Gaviria, Antonio; Javier Elola-Somoza, Francisco; Casariego-Vales, Emilio; Fernandez-Perez, Cristina; Gomez-Huelgas, Ricardo; Bernal, José Luis; Barba-Martín, Raquel

    2017-08-01

    To investigate the association between management of Internal Medical Units (IMUs) with outcomes (mortality and length of stay) within the Spanish National Health Service. Data on management were obtained from a descriptive transversal study performed among IMUs of the acute hospitals. Outcome indicators were taken from an administrative database of all hospital discharges from the IMUs. Spanish National Health Service. One hundred and twenty-four acute general hospitals with available data of management and outcomes (401 424 discharges). IMU risk standardized mortality rates were calculated using a multilevel model adjusted by Charlson Index. Risk standardized myocardial infarction and heart failure mortality rates were calculated using specific multilevel models. Length of stay was adjusted by complexity. Greater hospital complexity was associated with longer average length of stays (r: 0.42; P hospital mortality rates were higher at larger hospitals, but no significant differences were found when mortality was risk adjusted. There was an association between nurse workload with mortality rate for selected conditions (r: 0.25; P = 0.009). Safety committee and multidisciplinary ward rounds were also associated with outcomes. We have not found any association between complexity and intra-hospital mortality. There is an association between some management indicators with intra-hospital mortality and the length of stay. Better disease-specific outcomes adjustments and a larger number of IMUs in the sample may provide more insights about the association between management of IMUs with healthcare outcomes.

  5. Termination unit

    Energy Technology Data Exchange (ETDEWEB)

    Traeholt, Chresten; Willen, Dag; Roden, Mark; Tolbert, Jerry C.; Lindsay, David; Fisher, Paul W.; Nielsen, Carsten Thidemann

    2016-05-03

    Cable end section comprises end-parts of N electrical phases/neutral, and a thermally-insulation envelope comprising cooling fluid. The end-parts each comprises a conductor and are arranged with phase 1 innermost, N outermost surrounded by the neutral, electrical insulation being between phases and N and neutral. The end-parts comprise contacting surfaces located sequentially along the longitudinal extension of the end-section. A termination unit has an insulating envelope connected to a cryostat, special parts at both ends comprising an adapter piece at the cable interface and a closing end-piece terminating the envelope in the end-section. The special parts houses an inlet and/or outlet for cooling fluid. The space between an inner wall of the envelope and a central opening of the cable is filled with cooling fluid. The special part at the end connecting to the cryostat houses an inlet or outlet, splitting cooling flow into cable annular flow and termination annular flow.

  6. SGA-WZ: A New Strapdown Airborne Gravimeter

    Directory of Open Access Journals (Sweden)

    Kaidong Zhang

    2012-07-01

    Full Text Available Inertial navigation systems and gravimeters are now routinely used to map the regional gravitational quantities from an aircraft with mGal accuracy and a spatial resolution of a few kilometers. However, airborne gravimeter of this kind is limited by the inaccuracy of the inertial sensor performance, the integrated navigation technique and the kinematic acceleration determination. As the GPS technique developed, the vehicle acceleration determination is no longer the limiting factor in airborne gravity due to the cancellation of the common mode acceleration in differential mode. A new airborne gravimeter taking full advantage of the inertial navigation system is described with improved mechanical design, high precision time synchronization, better thermal control and optimized sensor modeling. Apart from the general usage, the Global Positioning System (GPS after differentiation is integrated to the inertial navigation system which provides not only more precise altitude information along with the navigation aiding, but also an effective way to calculate the vehicle acceleration. Design description and test results on the performance of the gyroscopes and accelerations will be emphasized. Analysis and discussion of the airborne field test results are also given.

  7. Novel calibration algorithm for a three-axis strapdown magnetometer.

    Science.gov (United States)

    Liu, Yan Xia; Li, Xi Sheng; Zhang, Xiao Juan; Feng, Yi Bo

    2014-05-14

    A complete error calibration model with 12 independent parameters is established by analyzing the three-axis magnetometer error mechanism. The said model conforms to an ellipsoid restriction, the parameters of the ellipsoid equation are estimated, and the ellipsoid coefficient matrix is derived. However, the calibration matrix cannot be determined completely, as there are fewer ellipsoid parameters than calibration model parameters. Mathematically, the calibration matrix derived from the ellipsoid coefficient matrix by a different matrix decomposition method is not unique, and there exists an unknown rotation matrix R between them. This paper puts forward a constant intersection angle method (angles between the geomagnetic field and gravitational field are fixed) to estimate R. The Tikhonov method is adopted to solve the problem that rounding errors or other errors may seriously affect the calculation results of R when the condition number of the matrix is very large. The geomagnetic field vector and heading error are further corrected by R. The constant intersection angle method is convenient and practical, as it is free from any additional calibration procedure or coordinate transformation. In addition, the simulation experiment indicates that the heading error declines from ±1° calibrated by classical ellipsoid fitting to ±0.2° calibrated by a constant intersection angle method, and the signal-to-noise ratio is 50 dB. The actual experiment exhibits that the heading error is further corrected from ±0.8° calibrated by the classical ellipsoid fitting to ±0.3° calibrated by a constant intersection angle method.

  8. SGA-WZ: A New Strapdown Airborne Gravimeter

    DEFF Research Database (Denmark)

    Huang, Yangming; Olesen, Arne Vestergaard; Wu, Meiping

    2012-01-01

    taking full advantage of the inertial navigation system is described with improved mechanical design, high precision time synchronization, better thermal control and optimized sensor modeling. Apart from the general usage, the Global Positioning System (GPS) after differentiation is integrated...

  9. An in situ hand calibration method using a pseudo-observation scheme for low-end inertial measurement units

    Science.gov (United States)

    Li, You; Niu, Xiaoji; Zhang, Quan; Zhang, Hongping; Shi, Chuang

    2012-10-01

    MEMS chips have become ideal candidates for various applications since they are small sized, light weight, have low power consumption and are extremely low cost and reliable. However, the performance of MEMS sensors, especially their biases and scale factors, is highly dependent on environmental conditions such as temperature. Thus a quick and convenient calibration is needed to be conducted by users in field without any external equipment or any expert knowledge of calibration. A novel and efficient in situ hand calibration method is presented to meet these demands in this paper. The algorithm of the proposed calibration method makes use of the navigation algorithm of the loosely-coupled GPS/INS integrated systems, but replaces the GPS observations with a kind of pseudo-observations, which can be stated as follows: if an inertial measurement unit (IMU) was rotating approximately around its measurement center, the range of its position and its linear velocity both would be within a limited scope. Using a Kalman filtering algorithm, the biases and scale factors of both accelerometer triad and gyroscope triad can be calibrated together within a short period (about 30 s), requiring only motions by hands. Real test results show that the proposed method is suitable for most consumer grade MEMS IMUs due to its zero cost, easy operation and sufficient accuracy.

  10. Development of an Inertial Measurement Unit for Unmanned Aerial Vehicles

    Science.gov (United States)

    2011-02-01

    Tri-axis accelerometers Dual Angular rate gyros Micro-Controller board Battery Rubber isolation stands wireless comunication module (XBee...STMicroelectronics Digital devices (lis3lv02dq) tri- axis accelerometer, (http://www.sparkfun.com/datasheets/IC/LIS3LV02D Q.pdf.hj). [5...STMicroelectronics Digital devices (lpr530al) dual axis rate gyro sensor, (http://www.sparkfun.com/datasheets/Sensors/IMU/lp r530al.pdf.) [6] STMicroelectronics

  11. Using SI Units in Astronomy

    Science.gov (United States)

    Dodd, Richard

    2011-12-01

    1. Introduction; 2. An introduction to SI units; 3. Dimensional analysis; 4. Unit of angular measure (radian); 5. Unit of time (second); 6. Unit of length (metre); 7. Unit of mass (kilogram); 8. Unit of luminous intensity (candela); 9. Unit of thermodynamic temperature (kelvin); 10. Unit of electric current (ampere); 11. Unit of amount of substance (mole); 12. Astronomical taxonomy; Index.

  12. Applications of Should Cost to Achieve Cost Reductions

    Science.gov (United States)

    2014-04-01

    Defense Acquisition University DDG . . . . . . . . . Guided Missile Destroyer Demo . . . . . . . . . . . . . . . . . Demonstration Dev ...Integrated Fire Control Network IMU . . . . . . . . . . Inertial Measurment Unit IOC . . . . . . .Initial Operational Capability IOT . . . . . . . . . Initial

  13. Malaria Treatment (United States)

    Science.gov (United States)

    ... a CDC Malaria Branch clinician. malaria@cdc.gov Malaria Treatment (United States) Recommend on Facebook Tweet Share Compartir Treatment of Malaria: Guidelines For Clinicians (United States) Download PDF version ...

  14. United Cerebral Palsy

    Science.gov (United States)

    ... be sure to follow us on Twitter . United Cerebral Palsy UCP educates, advocates and provides support services to ... Partners Merz Logo Sprint Relay Copyright © 2015 United Cerebral Palsy 1825 K Street NW Suite 600 Washington, DC ...

  15. Unit Cost Compendium Calculations

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Unit Cost Compendium (UCC) Calculations raw data set was designed to provide for greater accuracy and consistency in the use of unit costs across the USEPA...

  16. Establishing the Intermediate Unit.

    Science.gov (United States)

    Pennsylvania State Dept. of Education, Harrisburg.

    The State of Pennsylvania Act 102 establishes a system of 29 intermediate units, creates intermediate unit boards of directors, spells out their duties and functions, and provides a system of financing their operations. This handbook has been prepared by the Pennsylvania Department of Education to provide intermediate unit boards of directors,…

  17. Unitals in Projective Planes

    CERN Document Server

    Barwick, Susan

    2008-01-01

    Unitals are key structures in projective planes, and have connections with other structures in algebra. This book presents a monograph on unitals embedded in finite projective planes. It offers a survey of the research literature on embedded unitals. It is suitable for graduate students and researchers who want to learn about this topic

  18. Freestanding midwifery units versus obstetric units

    DEFF Research Database (Denmark)

    Overgaard, Charlotte; Fenger-Grøn, Morten; Sandall, Jane

    2012-01-01

    women intending to give birth in two freestanding midwifery units (FMU) versus two obstetric units in Denmark differed by level of social disadvantage Methods The study was designed as a cohort study with a matched control group. It included 839 lowrisk women intending to give birth in an FMU, who were...... prospectively and individually matched on nine selected obstetric/socio-economic factors to 839 low-risk women intending OU birth. Educational level was chosen as a proxy for social position. Analysis was by intention-to-treat. Results Women intending to give birth in an FMU had a significantly higher...

  19. ENERGY STAR Unit Reports

    Data.gov (United States)

    Department of Housing and Urban Development — These quarterly Federal Fiscal Year performance reports track the ENERGY STAR qualified HOME units that Participating Jurisdictions record in HUD's Integrated...

  20. High Precision Fiber SINS with Spin Technology

    Institute of Scientific and Technical Information of China (English)

    孙伟; 孙枫; 王大雪

    2013-01-01

    Fiber strapdown inertial navigation system (FSINS) is presently used in several applications related to marine navigation. However, the absolute position from FSINS contains the error that increases with time, which prevents its long-term use for the ship cruise. In order to improve the performance of FSINS based on our present inertial sensors, the spin technology was proposed in the system to mitigate the navigation errors and a prototype of the proposed system was developed in Navigation Lab. The prototype contains the IMU, temperature controller, rotating configuration, navigation and I/O electronics group, control and display, power supply subsystem and other modules. In the proposed spin technology, the IMU is rotated back and forth in azimuth through four orthogonal positions relative to the ship’s longitudinal axis. Experimental testing was conducted for the prototype in the laboratory and the results showed that the RFSINS’s navigation performance is improved 10 times.

  1. 31 CFR 535.321 - United States; continental United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States; continental United... General Definitions § 535.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof including the Trust Territory...

  2. 31 CFR 515.321 - United States; continental United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States; continental United... General Definitions § 515.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including the Trust Territory...

  3. 31 CFR 500.321 - United States; continental United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States; continental United... General Definitions § 500.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including U.S. trust...

  4. REACH. Air Conditioning Units.

    Science.gov (United States)

    Garrison, Joe; And Others

    As a part of the REACH (Refrigeration, Electro-Mechanical, Air-Conditioning, Heating) electromechanical cluster, this student manual contains individualized instructional units in the area of air conditioning. The instructional units focus on air conditioning fundamentals, window air conditioning, system and installation, troubleshooting and…

  5. REACH. Air Conditioning Units.

    Science.gov (United States)

    Garrison, Joe; And Others

    As a part of the REACH (Refrigeration, Electro-Mechanical, Air-Conditioning, Heating) electromechanical cluster, this student manual contains individualized instructional units in the area of air conditioning. The instructional units focus on air conditioning fundamentals, window air conditioning, system and installation, troubleshooting and…

  6. Conflict Resolution Unit.

    Science.gov (United States)

    Busselle, Tish

    This 7-day unit, intended for use with secondary students, contains a statement of rationale and objectives, lesson plans, class assignments, teacher and student bibliographies, and suggestions for instructional materials on conflict resolution between individuals, groups, and nations. Among the six objectives listed for the unit are: 1) explain…

  7. REACH. Refrigeration Units.

    Science.gov (United States)

    Snow, Rufus; And Others

    As a part of the REACH (Refrigeration, Electro-Mechanical, Air-Conditioning, Heating) electromechanical cluster, this student manual contains individualized instructional units in the area of refrigeration. The instructional units focus on refrigeration fundamentals, tubing and pipe, refrigerants, troubleshooting, window air conditioning, and…

  8. Unit on Existentialism.

    Science.gov (United States)

    Rowell, Bobby

    1971-01-01

    A unit on existentialism is suggested to counteract the indifferent attitude that students have toward much of the literature with which they are presented. The key to a successful literature unit is immediate and total student involvement. Topics, authors, and works which may be used to arouse student interest are presented. (CK)

  9. United nations Orchestra

    CERN Multimedia

    MusiClub

    MusiClub United nations Orchestra www.ungenevaorchestra.ch An organizing committee has taken the initiative to create an Orchestra of the united nations at Geneva. In the context of this initiative, musicians in the following categories are invited to become members of the Orchestra and the Association: Active or retired staff of International organizations in Geneva; Active or retired employees of Permanent Missions to the United Nations at Geneva; as well as children and spouses of the above persons. For enrolment or for additional information, please contact: un.orchestra@yahoo.com

  10. Observational Study of 180° Turning Strategies Using Inertial Measurement Units and Fall Risk in Poststroke Hemiparetic Patients

    Directory of Open Access Journals (Sweden)

    Rémi Pierre-Marie Barrois

    2017-05-01

    Full Text Available ObjectiveWe analyzed spontaneous 180° turning strategies in poststroke hemiparetic patients by using inertial measurement units (IMUs and the association of turning strategies with risk of falls.MethodsWe included right paretic (RP and left paretic (LP post-stroke patients, and healthy controls (HCs from a physical and rehabilitation department in France between July 2015 and October 2015. All subjects were right-handed and right-footed for mobilization tasks. Participants were instructed to turn 180° in a self-selected direction after a 10-m walk while wearing three IMUs on their trunk and both feet. We defined three turning patterns based on the number of external steps (pattern I = 1; II = 2–4 steps; and III ≥ 5 and four turning strategies based on the side chosen to turn (healthy or paretic and the stance limb used during the first step of the turn (healthy or paretic. Falls in the 6 months after measurement were investigated.ResultsWe included 17 RP [mean (SD age 57.5 (9.5 years (range 43–73], 20 LP patients [mean age 60.7 (8.8 years (range 43–63], and 15 HCs [mean age 56.7 (16.1 years (range 36–83]. The LP and RP groups behaved similarly in turning patterns, but 90% of LP patients turned spontaneously to the paretic side versus 59% of RP patients. This difference increased with turning strategies: 85% of LP versus 29% of RP patients used strategy 4 (paretic turn side with paretic limb. Patients using strategy 4 had the highest rate of falls.ConclusionWe propose to consider spontaneous turning strategies as new indicators to evaluate the risk of fall after stroke. IMU could be routinely used to identify this risk and guide balance rehabilitation programs.

  11. Does size matter? Animal units and animal unit months

    Science.gov (United States)

    Lamar Smith; Joe Hicks; Scott Lusk; Mike Hemmovich; Shane Green; Sarah McCord; Mike Pellant; John Mitchell; Judith Dyess; Jim Sprinkle; Amanda Gearhart; Sherm Karl; Mike Hannemann; Ken Spaeth; Jason Karl; Matt Reeves; Dave Pyke; Jordan Spaak; Andrew Brischke; Del Despain; Matt Phillippi; Dave Weixelmann; Alan Bass; Jessie Page; Lori Metz; David Toledo; Emily Kachergis

    2017-01-01

    The concepts of animal units, animal unit months, and animal unit equivalents have long been used as standards for range management planning, estimating stocking rates, reporting actual use, assessing grazing fees, ranch appraisal, and other purposes. Increasing size of cattle on rangelands has led some to suggest that the definition of animal units and animal unit...

  12. Tax Unit Boundaries

    Data.gov (United States)

    Kansas Data Access and Support Center — The Statewide GIS Tax Unit boundary file was created through a collaborative partnership between the State of Kansas Department of Revenue Property Valuation...

  13. United Mitochondrial Disease Foundation

    Science.gov (United States)

    ... Other Ways to Give Matching Gifts Donate Your Car Online Options United Way Close About UMDF Our ... Rights Reserved | UMDF Donor Privacy Policy Facebook Twitter Google+ Youtube Vimeo Instagram Email STAY UPDATED! Join the ...

  14. Voltage verification unit

    Science.gov (United States)

    Martin, Edward J.

    2008-01-15

    A voltage verification unit and method for determining the absence of potentially dangerous potentials within a power supply enclosure without Mode 2 work is disclosed. With this device and method, a qualified worker, following a relatively simple protocol that involves a function test (hot, cold, hot) of the voltage verification unit before Lock Out/Tag Out and, and once the Lock Out/Tag Out is completed, testing or "trying" by simply reading a display on the voltage verification unit can be accomplished without exposure of the operator to the interior of the voltage supply enclosure. According to a preferred embodiment, the voltage verification unit includes test leads to allow diagnostics with other meters, without the necessity of accessing potentially dangerous bus bars or the like.

  15. Cereal Crops Research Unit

    Data.gov (United States)

    Federal Laboratory Consortium — The mission of the Cereal Crops Research Unit is to 1) conduct basic research to identify and understand the biological processes affecting the growth, development...

  16. Cereal Crops Research Unit

    Data.gov (United States)

    Federal Laboratory Consortium — The mission of the Cereal Crops Research Unit is to 1) conduct basic research to identify and understand the biological processes affecting the growth, development...

  17. Operable Unit Boundaries

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset consists of operable unit data from multiple Superfund sites in U.S. EPA Region 8. These data were acquired from multiple sources at different times and...

  18. Insects: An Interdisciplinary Unit

    Science.gov (United States)

    Leger, Heather

    2007-01-01

    The author talks about an interdisciplinary unit on insects, and presents activities that can help students practice communication skills (interpersonal, interpretive, and presentational) and learn about insects with hands-on activities.

  19. Dimensionless Units in the SI

    CERN Document Server

    Mohr, Peter J

    2014-01-01

    The International System of Units (SI) is supposed to be coherent. That is, when a combination of units is replaced by an equivalent unit, there is no additional numerical factor. Here we consider dimensionless units as defined in the SI, {\\it e.g.} angular units like radians or steradians and counting units like radioactive decays or molecules. We show that an incoherence may arise when different units of this type are replaced by a single dimensionless unit, the unit "one", and suggest how to properly include such units into the SI in order to remove the incoherence. In particular, we argue that the radian is the appropriate coherent unit for angles and that hertz is not a coherent unit in the SI. We also discuss how including angular and counting units affects the fundamental constants.

  20. Battery thermal management unit

    Science.gov (United States)

    Sanders, Nicholas A.

    1989-03-01

    A battery warming device has been designed which uses waste heat from an operating internal combustion engine to warm a battery. A portion of the waste heat is stored in the sensible and latent heat of a phase change type material for use in maintaining the battery temperature after the engine is shut off. The basic design of the device consists of a Phase Change Material (PCM) reservoir and a simple heat exchanger connected to the engineer's cooling system. Two types of units were built, tested and field trialed. A strap-on type which was strapped to the side of an automotive battery and was intended for the automotive after-market and a tray type on which a battery or batteries sat. This unit was intended for the heavy duty truck market. It was determined that both types of units increased the average cranking power of the batteries they were applied to. Although there were several design problems with the units such as the need for an automatic thermostatically controlled bypass valve, the overall feeling is that there is a market opportunity for both the strap-on and tray type battery warming units.

  1. Coherence for weak units

    CERN Document Server

    Joyal, André

    2009-01-01

    We define weak units in a semi-monoidal 2-category $\\CC$ as cancellable pseudo-idempotents: they are pairs $(I,\\alpha)$ where $I$ is an object such that tensoring with $I$ from either side constitutes a biequivalence of $\\CC$, and $\\alpha: I \\tensor I \\to I$ is an equivalence in $\\CC$. We show that this notion of weak unit has coherence built in: Theorem A: $\\alpha$ has a canonical associator 2-cell, which automatically satisfies the pentagon equation. Theorem B: every morphism of weak units is automatically compatible with those associators. Theorem C: the 2-category of weak units is contractible if non-empty. Finally we show (Theorem E) that the notion of weak unit is equivalent to the notion obtained from the definition of tricategory: $\\alpha$ alone induces the whole family of left and right maps (indexed by the objects), as well as the whole family of Kelly 2-cells (one for each pair of objects), satisfying the relevant coherence axioms.

  2. Dispersion in unit disks

    CERN Document Server

    Dumitrescu, Adrian

    2009-01-01

    We present two new approximation algorithms with (improved) constant ratios for selecting $n$ points in $n$ unit disks such that the minimum pairwise distance among the points is maximized. (I) A very simple $O(n \\log{n})$-time algorithm with ratio 0.5110 for disjoint unit disks. In combination with an algorithm of Cabello \\cite{Ca07}, it yields a $O(n^2)$-time algorithm with ratio of 0.4487 for dispersion in $n$ not necessarily disjoint unit disks. (II) A more sophisticated LP-based algorithm with ratio 0.6495 for disjoint unit disks that uses a linear number of variables and constraints, and runs in polynomial time. The algorithm introduces a novel technique which combines linear programming and projections for approximating distances. The previous best approximation ratio for disjoint unit disks was 1/2. Our results give a partial answer to an open question raised by Cabello \\cite{Ca07}, who asked whether 1/2 could be improved.

  3. Signal processing unit

    Energy Technology Data Exchange (ETDEWEB)

    Boswell, J.

    1983-01-01

    The architecture of the signal processing unit (SPU) comprises an ROM connected to a program bus, and an input-output bus connected to a data bus and register through a pipeline multiplier accumulator (pmac) and a pipeline arithmetic logic unit (palu), each associated with a random access memory (ram1,2). The system pulse frequency is from 20 mhz. The pmac is further detailed, and has a capability of 20 mega operations per second. There is also a block diagram for the palu, showing interconnections between the register block (rbl), separator for bus (bs), register (reg), shifter (sh) and combination unit. The first and second rams have formats 64*16 and 32*32 bits, respectively. Further data are a 5-v power supply and 2.5 micron n-channel silicon gate mos technology with about 50000 transistors.

  4. Indoor integrated navigation and synchronous data acquisition method for Android smartphone

    Science.gov (United States)

    Hu, Chunsheng; Wei, Wenjian; Qin, Shiqiao; Wang, Xingshu; Habib, Ayman; Wang, Ruisheng

    2015-08-01

    Smartphones are widely used at present. Most smartphones have cameras and kinds of sensors, such as gyroscope, accelerometer and magnet meter. Indoor navigation based on smartphone is very important and valuable. According to the features of the smartphone and indoor navigation, a new indoor integrated navigation method is proposed, which uses MEMS (Micro-Electro-Mechanical Systems) IMU (Inertial Measurement Unit), camera and magnet meter of smartphone. The proposed navigation method mainly involves data acquisition, camera calibration, image measurement, IMU calibration, initial alignment, strapdown integral, zero velocity update and integrated navigation. Synchronous data acquisition of the sensors (gyroscope, accelerometer and magnet meter) and the camera is the base of the indoor navigation on the smartphone. A camera data acquisition method is introduced, which uses the camera class of Android to record images and time of smartphone camera. Two kinds of sensor data acquisition methods are introduced and compared. The first method records sensor data and time with the SensorManager of Android. The second method realizes open, close, data receiving and saving functions in C language, and calls the sensor functions in Java language with JNI interface. A data acquisition software is developed with JDK (Java Development Kit), Android ADT (Android Development Tools) and NDK (Native Development Kit). The software can record camera data, sensor data and time at the same time. Data acquisition experiments have been done with the developed software and Sumsang Note 2 smartphone. The experimental results show that the first method of sensor data acquisition is convenient but lost the sensor data sometimes, the second method is much better in real-time performance and much less in data losing. A checkerboard image is recorded, and the corner points of the checkerboard are detected with the Harris method. The sensor data of gyroscope, accelerometer and magnet meter have

  5. Allocating multiple units

    DEFF Research Database (Denmark)

    Tranæs, Torben; Krishna, Kala

    2002-01-01

    This paper studies the allocation and rent distribution in multi-unit, combinatorial-bid auctions under complete information. We focus on the natural multi-unit analogue of the first-price auction, where buyers bid total payments, pay their bids, and where the seller allocates goods to maximize his...... revenue. While there are many equilibria in this auction, only efficient equilibria remain when the truthful equilibrium restriction of the menu-auction literature is used. Focusing on these equilibria we first show that the first-price auction just described is revenue and outcome equivalent to a Vickrey...

  6. United States Attorney Prosecutions

    Science.gov (United States)

    1993-10-01

    Berceda, 572 F.2d 630 (9th Cir. 1978).. A mere request, such as that made by the defendant, is not sufficient; United States v. Trejo- Zambrano , 582 F.2d...a mere request and more than mere speculation that disclosure will be helpful. United States v. Trejo- Zambrano , 582 F.2d 460 (9th Cir. 1978), eect. dt...both known and unknown to the Grand Jury, including Lane Boudreau, Scott Willard Holland, James Allen Halperin, Maria Ximena Erlandsen, Derek Adrian

  7. Women's Rights Unit.

    Science.gov (United States)

    Weiss, Helen; Weigel, Margaret

    Designed for use in the intermediate grades, this interdisciplinary unit helps students examine traditional and modern roles of women. Fourteen lessons focus on women's activities in colonial America, reasons for women's discontent, the women's rights movement of the 1800's, changes in the roles of women, enfranchisement of women, women's role…

  8. Consumer Mathematics. Teaching Units.

    Science.gov (United States)

    North Carolina State Dept. of Public Instruction, Raleigh.

    GRADES OR AGES: Secondary school. SUBJECT MATTER: Consumer mathematics including--money management, transportation, probability, swindles and gyps, insurance, housing, taxes, consumer credit, banks, savings, and investments. ORGANIZATION AND PHYSICAL APPEARANCE: The guide is divided into ten parallel units, one for each of the above areas, which…

  9. United in change

    NARCIS (Netherlands)

    Hanneke Posthumus; Josje den Ridder; Joep de Hart

    2014-01-01

    Original title: Verenigd in verandering The importance of citizens who unite in civil society organisations is broadly recognised. Organisations bind people to each other, to the community and to the political system. How are civil-society organisations in the Netherlands faring? Is there

  10. Outdoorsman, Unit III.

    Science.gov (United States)

    Alberta Dept. of Agriculture, Edmonton.

    The third and final unit of the 4-H Outdoorsman Program covers the most advanced and challenging campcraft skills for 4-H members in British Columbia, Alberta, Saskatchewan and Manitoba. Survival camping (including building shelters and finding food), in-depth map-reading and orienteering, game management, hiking themes and recordkeeping are all…

  11. Sickle Cell Unit.

    Science.gov (United States)

    Canipe, Stephen L.

    Included in this high school biology unit on sickle cell anemia are the following materials: a synopsis of the history of the discovery and the genetic qualities of the disease; electrophoresis diagrams comparing normal, homozygous and heterozygous conditions of the disease; and biochemical characteristics and population genetics of the disease. A…

  12. Whale Teaching Unit.

    Science.gov (United States)

    Peninsula Humane Society, San Mateo, CA.

    Materials in this teaching unit are designed to foster an interest in whale preservation among intermediate grade and junior high school students. Several readings provide background information on various types of whales and the economic value of whales. Student activities include a true and false game, a crossword, and a mobile. A resource list…

  13. Whale Teaching Unit.

    Science.gov (United States)

    Peninsula Humane Society, San Mateo, CA.

    Materials in this teaching unit are designed to foster an interest in whale preservation among intermediate grade and junior high school students. Several readings provide background information on various types of whales and the economic value of whales. Student activities include a true and false game, a crossword, and a mobile. A resource list…

  14. Transfer of manufacturing units

    DEFF Research Database (Denmark)

    Madsen, Erik Skov; Riis, Jens Ove; Sørensen, Brian Vejrum

    2008-01-01

    The ongoing and unfolding relocation of activities is one of the major trends, that calls for attention in the domain of operations management. In particular, prescriptive models outlining: stages of the process, where to locate, and how to establish the new facilities have been studied, while...... and dilemmas to be addressed when transferring manufacturing units....

  15. Multiple IMU system hardware interface design, volume 2

    Science.gov (United States)

    Landey, M.; Brown, D.

    1975-01-01

    The design of each system component is described. Emphasis is placed on functional requirements unique in this system, including data bus communication, data bus transmitters and receivers, and ternary-to-binary torquing decision logic. Mechanization drawings are presented.

  16. External Aiding Methods for IMU-Based Navigation

    Science.gov (United States)

    2016-11-26

    system in the dead- reckoning of the vehicle’s position and attitude . Due to the nature of sensors, the measurement of the linear acceleration and angular...6 3.2.3 Velocity Random Walk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.2.4 Scale Factor Error...Standard Deviation in Position and Attitude . . . . . . . . . . . . . . . . . . . . . . . . 27 4.3.2 Standard Deviation with External Aiding

  17. Vehicle state estimation using GPS/IMU integration

    NARCIS (Netherlands)

    Wang, Y.; Mangnus, J.; Kostić, D.; Nijmeijer, H.; Jansen, S.T.H.

    2011-01-01

    New driver support systems require knowledge of the vehicle position with great accuracy and reliability. Satellite navigation (GNSS) is generally insufficiently accurate for positioning and as an alternative to using a ground station, combinations with high quality motion sensors are used in so-cal

  18. Vision-IMU based collaborative control of a blind UAV

    NARCIS (Netherlands)

    Hoogervorst, R.; Stramigioli, Stefano; Wopereis, Han Willem; Fumagalli, Matteo

    2015-01-01

    Position estimation of UAVs is usually done using onboard sensors such as GPS and camera. However, in certain practical situations, the measurements of both the GPS and the onboard camera of the UAV might not always be available or reliable. This paper investigates the possibility to overcome

  19. Improved Feature Matching for Mobile Devices with IMU.

    Science.gov (United States)

    Masiero, Andrea; Vettore, Antonio

    2016-08-05

    Thanks to the recent diffusion of low-cost high-resolution digital cameras and to the development of mostly automated procedures for image-based 3D reconstruction, the popularity of photogrammetry for environment surveys is constantly increasing in the last years. Automatic feature matching is an important step in order to successfully complete the photogrammetric 3D reconstruction: this step is the fundamental basis for the subsequent estimation of the geometry of the scene. This paper reconsiders the feature matching problem when dealing with smart mobile devices (e.g., when using the standard camera embedded in a smartphone as imaging sensor). More specifically, this paper aims at exploiting the information on camera movements provided by the inertial navigation system (INS) in order to make the feature matching step more robust and, possibly, computationally more efficient. First, a revised version of the affine scale-invariant feature transform (ASIFT) is considered: this version reduces the computational complexity of the original ASIFT, while still ensuring an increase of correct feature matches with respect to the SIFT. Furthermore, a new two-step procedure for the estimation of the essential matrix E (and the camera pose) is proposed in order to increase its estimation robustness and computational efficiency.

  20. Vision-IMU based collaborative control of a blind UAV

    NARCIS (Netherlands)

    Hoogervorst, R.; Stramigioli, S.; Wopereis, H.W.; Fumagalli, M.

    2015-01-01

    Position estimation of UAVs is usually done using onboard sensors such as GPS and camera. However, in certain practical situations, the measurements of both the GPS and the onboard camera of the UAV might not always be available or reliable. This paper investigates the possibility to overcome situat

  1. Personal navigation method based on foot-mounted MEMS inertial/magnetic measurement unit%光电跟踪模型噪声卡尔曼滤波算法

    Institute of Scientific and Technical Information of China (English)

    王秋平; 李凤; 马春林

    2012-01-01

    为减小滤波性能对跟踪目标状态空间模型噪声的敏感性,提出一种基于新息同时更新系统噪声方差和测量噪声方差方法,并将其与非线性卡尔曼滤波类算法相结合,构成一类适用于光电跟踪目标的自适应非线性卡尔曼滤波算法.同时将此方法应用到非线性测量光电跟踪系统中,并与扩展卡尔曼滤波和U卡尔曼滤波进行性能对比.仿真实验结果证明该方法可以实时调整系统噪声方差和测量噪声方差,有效地避免由于系统模型噪声统计特性不准确所带来的滤波性能下降的问题,而且其性能明显优于扩展卡尔曼滤波和U卡尔曼滤波.%In order to relieve the dependence of personal navigation on global navigation satellite system (GNSS), a personal navigation method was studied based on foot-mounted MEMS inertial/ magnetic measurement unit. Navigation information including attitude, velocity and position was obtained through the data from MEMS inertial measurement unit and strapdown inertial navigation algorithm. The azimuth of the navigation system was obtained by magnetic sensors. The errors of MEMS inertial navigation system and random errors of inertial sensors were modified by applying gait phase detection and zero-velocity update, so that the accumulate speed of the positioning errors was slowed down. The navigation experiment result shows that, the navigation errors of straight line and rectangle route retain about 2 m and 6 m during about 9 minutes' walking. The errors take up 1.1% and 2.5% of the whole distances of walking respectively. The experiment conclusion proves that the proposed method can effectively improve the positioning precision of personal navigation system, and can achieve personal positioning for longer time under the environment that GNSS signal is attenuated or become failure.

  2. Miniaturized high-performance MEMS accelerometer detector

    Science.gov (United States)

    Gonseth, Stephan; Rudolf, Felix; Eichenberger, Christoph; Durrant, Dick; Airey, Phil

    2015-06-01

    In the framework of the demonstration of European capabilities for future space exploration mission, a high-performance miniaturized MEMS accelerometer detector is developed by Colibrys for incorporation into a compact inertial measurement unit (IMU). The envisaged missions where a miniaturized IMU is under development by SEA should cover: Aerobraking;

  3. Magnetic distortion in motion labs, implications for validating inertial magnetic sensors.

    NARCIS (Netherlands)

    Vries, W.H. de; Veeger, H.E.; Baten, C.T.; Helm, F.C.T. van der

    2009-01-01

    BACKGROUND: Ambulatory 3D orientation estimation with Inertial Magnetic Sensor Units (IMU's) use the earth magnetic field. The magnitude of distortion in orientation in a standard equipped motion lab and its effect on the accuracy of the orientation estimation with IMU's is addressed. METHODS: Orien

  4. Laser color recording unit

    Science.gov (United States)

    Jung, E.

    1984-05-01

    A color recording unit was designed for output and control of digitized picture data within computer controlled reproduction and picture processing systems. In order to get a color proof picture of high quality similar to a color print, together with reduced time and material consumption, a photographic color film material was exposed pixelwise by modulated laser beams of three wavelengths for red, green and blue light. Components of different manufacturers for lasers, acousto-optic modulators and polygon mirrors were tested, also different recording methods as (continuous tone mode or screened mode and with a drum or flatbed recording principle). Besides the application for the graphic arts - the proof recorder CPR 403 with continuous tone color recording with a drum scanner - such a color hardcopy peripheral unit with large picture formats and high resolution can be used in medicine, communication, and satellite picture processing.

  5. LIDAR COMBINED SCANNING UNIT

    Directory of Open Access Journals (Sweden)

    V. V. Elizarov

    2016-11-01

    Full Text Available Subject of Research. The results of lidar combined scanning unit development for locating leaks of hydrocarbons are presented The unit enables to perform high-speed scanning of the investigated space in wide and narrow angle fields. Method. Scanning in a wide angular field is produced by one-line scanning path by means of the movable aluminum mirror with a frequency of 20Hz and amplitude of 20 degrees of swing. Narrowband scanning is performed along a spiral path by the deflector. The deflection of the beam is done by rotation of the optical wedges forming part of the deflector at an angle of ±50. The control function of the scanning node is performed by a specialized software product written in C# programming language. Main Results. This scanning unit allows scanning the investigated area at a distance of 50-100 m with spatial resolution at the level of 3 cm. The positioning accuracy of the laser beam in space is 15'. The developed scanning unit gives the possibility to browse the entire investigated area for the time not more than 1 ms at a rotation frequency of each wedge from 50 to 200 Hz. The problem of unambiguous definition of the beam geographical coordinates in space is solved at the software level according to the rotation angles of the mirrors and optical wedges. Lidar system coordinates are determined by means of GPS. Practical Relevance. Development results open the possibility for increasing the spatial resolution of scanning systems of a wide range of lidars and can provide high positioning accuracy of the laser beam in space.

  6. Unit 5. Thermodynamics (Summary)

    OpenAIRE

    Beléndez Vázquez, Augusto

    2012-01-01

    Summary of the "Unit 5. Thermodynamics" of course "Physical Foundations of Engineering I". Degree in Sound and Image Engineering, in Telecommunications. Polytechnic School of the University of Alicante Resumen del "Tema 5. Termodinámica" de la asignatura "Fundamentos Físicos de la Ingeniería I". Grado en Ingeniería en Sonido e Imagen en Telecomunicaciones. Escuela Politécnica Superior. Universidad de Alicante.

  7. UNIT COMMITMENT: A NEW TRUNCATED METHOD OF UNIT ...

    African Journals Online (AJOL)

    NIJOTECH

    limits, minimum up/down times. Other ... incremental heat rate in ₦/hour for unit i ... approaches to treating thermal unit during its ... (d) Load Balance: During each interval of time, k, the .... The unit information and initial conditions are shown in.

  8. Dynamic Torque Calibration Unit

    Science.gov (United States)

    Agronin, Michael L.; Marchetto, Carl A.

    1989-01-01

    Proposed dynamic torque calibration unit (DTCU) measures torque in rotary actuator components such as motors, bearings, gear trains, and flex couplings. Unique because designed specifically for testing components under low rates. Measures torque in device under test during controlled steady rotation or oscillation. Rotor oriented vertically, supported by upper angular-contact bearing and lower radial-contact bearing that floats axially to prevent thermal expansion from loading bearings. High-load capacity air bearing available to replace ball bearings when higher load capacity or reduction in rate noise required.

  9. Small Unit Operations

    Science.gov (United States)

    2007-11-02

    best demonstrated value for small (< AA size) lithium - thionyl - chloride batteries (Halpert 1993). Equation (2-3) shows that the solar power...However, this energy den- sity this is only ~ 3 times larger than the demonstrated performance of the best lithium batteries , and the fuel cells are...Units 13 2.2.2 ASIC Capability 15 2.2.3 Power and Size 17 2.2.4 Cost 19 2.3 Power Sources 20 2.3.1 Batteries 21 2.3.2 Solar Augmentation

  10. Order Units in a *-Algebra

    Indian Academy of Sciences (India)

    Anil K Karn

    2003-02-01

    Order unit property of a positive element in a *-algebra is defined. It is proved that precisely projections satisfy this order theoretic property. This way, unital hereditary *-subalgebras of a *-algebra are characterized.

  11. DS796 California Groundwater Units

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The California Groundwater Units dataset classifies and delineates the State into one of three groundwater based polygon units: (1) those areas defined as alluvial...

  12. Trend of hydraulic units

    Energy Technology Data Exchange (ETDEWEB)

    Deshimaru, Jun' ichi

    1988-11-01

    The gear, vane and piston pumps occupy a more then 90% share in the hydraulic pumps. Comparatively large pumps are mainly variable delivery piston pumps. The piston pumps are comparatively high in output density (output per unit weight), indicating the hydraulic pump in performance, and tend to become higher and higher in it. Though they are mainly 210 to 350kgf/cm/sup 2/ in rated pressure, some of them come to surpass 400kgf/cm/sup 3/ in it. While the progress in computation also requires the high speed operation, high accuracy and other severe conditions for the hydraulic units, which accordingly and increasingly intensify the requirement for hydraulic oil in abrasion resistibility, oxidation stability and response characteristics. While cavitation comes to easily occur, which considerably and disadvantageously influences hydraulic oil in life through degradation, noise level and respondingness. From now on, the development of high performance oil and study of mechanical structure are important. 19 references, 9 figures, 2 tables.

  13. An ISOLDE target unit

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    A good dozen different targets are available for ISOLDE, made of different materials and equipped with different kinds of ion-sources, according to the needs of the experiments. Each separator (GPS: general purpose; HRS: high resolution) has its own target. Because of the high radiation levels, robots effect the target changes, about 80 times per year. In the standard unit shown in picture _01, the target is the cylindrical object in the front. It contains uranium-carbide kept at a temperature of 2200 deg C, necessary for the isotopes to be able to escape. At either end, one sees the heater current leads, carrying 700 A. The Booster beam, some 3E13 protons per pulse, enters the target from left. The evaporated isotope atoms enter a hot-plasma ion source (the black object behind the target). The whole unit sits at 60 kV potential (pulsed in synchronism with the arrival of the Booster beam) which accelerates the ions (away from the viewer) towards one of the 2 separators.

  14. Snakes: An Integrated Unit Plan.

    Science.gov (United States)

    Lawrence, Lisa

    This document presents an integrated unit plan on snakes targeting second grade students. Objectives of the unit include developing concepts of living things, understanding the contribution and importance of snakes to the environment, and making connections between different disciplines. The unit integrates the topic of snakes into the areas of…

  15. Design of hydraulic recuperation unit

    Directory of Open Access Journals (Sweden)

    Jandourek Pavel

    2016-01-01

    Full Text Available This article deals with design and measurement of hydraulic recuperation unit. Recuperation unit consist of radial turbine and axial pump, which are coupled on the same shaft. Speed of shaft with impellers are 6000 1/min. For economic reasons, is design of recuperation unit performed using commercially manufactured propellers.

  16. United Arab Emirates.

    Science.gov (United States)

    1985-02-01

    This discussion of the United Arab Emirates focuses on the following: the people; geography; history; government; political conditions; defense; the economy; foreign relations; and relations between the US and the United Arab Emirates. In 1983 the population was estimated at 1,194,000. In 1984 the annual growth rate was negative. Life expectancy is about 60 years. Fewer than 20% of the population are UAE citizens. Indigenous Emiris are Arab; the rest of the population includes significant numbers of other Arabs -- Palestinians, Egyptians, Jordanians, Yemenis, Omanis, as well as many Iranians, Pakistanis, Indians, and West Europeans, especially in Dubai. The UAE is in the eastern Arabian Peninsula, bounded on the north by the Persian Gulf. European and Arab pirates roamed the Trucial Coast area from the 17th century into the 19th century. Early British expeditions against the pirates led to further campaigns against their headquarters. Piracy continued intermittently until 1835, when the shaikhs agreed not to engage in hostilities at sea. Primarily in reaction to the ambitions of other European countries, the UK and the Trucial States established closer bonds in an 1892 treaty. In 1968 the British government announced its decision, reaffirmed in March 1971, to end the treaty relationship with the gulf shaikhdoms. When the British protective treaty with the Trucial Shaikhdoms ended on December 1, they became fully independent. On December 2, 1971, 6 of them entered into a union called the United Arab Emirates. The 7th, Ras al-Khaimah, joined in early 1972. Administratively, the UAE is a loose federation of 7 emirates, each with its own ruler. The pace at which local government in each emirate is evolving, from traditional to modern, is set primarily by the ruler. Under the provisional constitution of 1971, each emirate reserves considerable powers, including control over mineral rights, taxation, and police powers. In this milieu, the growth of federal powers has

  17. Learning unit: Thin lenses

    Science.gov (United States)

    Nita, L.-S.

    2012-04-01

    Learning unit: Thin lenses "Why objects seen through lenses are sometimes upright and sometimes reversed" Nita Laura Simona National College of Arts and Crafts "Constantin Brancusi", Craiova, Romania 1. GEOMETRIC OPTICS. 13 hours Introduction (models, axioms, principles, conventions) 1. Thin lenses (Types of lenses. Defining elements. Path of light rays through lenses. Image formation. Required physical quantities. Lens formulas). 2. Lens systems (Non-collated lenses. Focalless systems). 3. Human eye (Functioning as an optical system. Sight defects and their corrections). 4. Optical instruments (Characteristics exemplified by a magnifying glass. Paths of light rays through a simplified photo camera. Path of light rays through a classical microscope) (Physics curriculum for the IXth grade/ 2011). This scenario exposes a learning unit based on experimental sequences (defining specific competencies), as a succession of lessons started by noticing a problem whose solution assumes the setup of an experiment under laboratory conditions. Progressive learning of theme objectives are realised with sequential experimental steps. The central cognitive process is the induction or the generalization (development of new knowledge based on observation of examples or counterexamples of the concept to be learnt). Pupil interest in theme objectives is triggered by problem-situations, for example: "In order to better see small objects I need a magnifying glass. But when using a magnifier, small object images are sometimes seen upright and sometimes seen reversed!" Along the way, pupils' reasoning will converge to the idea: "The image of an object through a lens depends on the relative distances among object, lens, and observer". Associated learning model: EXPERIMENT Specific competencies: derived from the experiment model, in agreement with the following learning unit steps I. Evoking - Anticipation: Size of the problem, formulation of hypotheses and planning of experiment. II

  18. Last call for units

    Science.gov (United States)

    Randall, Stuart; Rosen, Ronald; Jones, Clifford; Bean, Leonard W.; Lane, Frank

    2009-09-01

    I am writing with regard to Kevin McGuigan's definition of the darwin unit, Dw, as "the mathematical probability of one undergraduate (or faculty) fatality per practical if the person in question is left to their own devices" (July p60). Although it is clear how the loss of genitals in a laboratory accident would result in a student's removal from the gene pool, McGuigan does not explain how the loss of finger (a 1 mDw event, he suggests) might impede procreation in the slightest. Perhaps McGuigan is confusing Darwin's evolution by natural selection with Lamarck's discredited theory of evolution by the inheritance of acquired characteristics. If so, the gulf between physicists and biologists seems as wide as ever.

  19. Forward Deployed Robotic Unit

    Science.gov (United States)

    Brendle, Bruce E., Jr.; Bornstein, Jonathan A.

    2000-07-01

    Forward Deployed Robotic Unit (FDRU) is a core science and technology objective of the US Army, which will demonstrate the impact of autonomous systems on all phases of future land warfare. It will develop, integrate and demonstrate technology required to achieve robotic and fire control capabilities for future land combat vehicles, e.g., Future Combat Systems, using a system of systems approach that culminates in a field demonstration in 2005. It will also provide the required unmanned assets and conduct the demonstration. Battle Lab Warfighting Experiments and data analysis required to understand the effects of unmanned assets on combat operations. The US Army Tank- Automotive & Armaments Command and the US Army Research Laboratory are teaming in an effort to leverage prior technology achievements in the areas of autonomous mobility, architecture, sensor and robotics system integration; advance the state-of-the-art in these areas; and to provide field demonstration/application of the technologies.

  20. [United theory of aging].

    Science.gov (United States)

    Trubitsyn, A G

    2012-01-01

    In attempts to develop a means of life prolongation the humankind has created more than three hundred theories of the aging; each of them offers the original cause of aging. However, none of them has given practical result by now. The majority of the theories have now only historical interest. There are several different theories that are mainly under consideration currently. They are based on reliable, proven evidence: the free radical theory, the protein error theory, the replicative senescence theory, the theory of reparation weakening, the immunological theory, several versions of neuroendocrinal theories, and programmed aging theory. The theory presented here is based on conception that the life as the phenomenon represents many of the interconnected physical and chemical processes propelled by energy of the mitochondrial bioenergetical machine. Gradual degradation of all vital processes is caused by the programmed decrease in level of bioenergetics. This theory unites all existing theories of aging constructed on authentic facts: it is shown, that such fundamental phenomena accompanying aging process as the increase in level of reactive oxygen species (ROS), the decrease in the general level of protein synthesis, the limitation of cellular dividing (Haiflick limit), decrease in efficiency of reparation mechanisms are caused by bioenergetics attenuation. Each of these phenomena in turn generates a number of harmful secondary processes. Any of the theories bases on one of these destructive phenomena or their combination. Hence, each of them describes one of sides of process of the aging initially caused by programmed decrease of level of bioenergetics. This united theory gives the chance to understand the nature of aging clock and explains a phenomenon of increase in longevity at the condition of food restriction. Failures of attempts to develop means from aging are explained by that the manipulations with the separate secondary phenomena of attenuation of

  1. Friendly units for coldness

    CERN Document Server

    Fraundorf, P

    2006-01-01

    Measures of temperature that center around human experience get lots of use. Of course thermal physics insights of the last century have shown that reciprocal temperature (1/kT) has applications that temperature addresses less well. In addition to taking on negative absolute values under population inversion (e.g. of magnetic spins), bits and bytes turn 1/kT into an informatic measure of the thermal ambient for developing correlations within any complex system. We show here that, in the human-friendly units of bytes and food Calories, water freezes when 1/kT ~200 ZB/Cal or kT ~5 Cal/YB. Casting familiar benchmarks into these terms shows that habitable human space requires coldness values (part of the time, at least) between 0 and 40 ZB/Cal with respect body temperature ~100 degrees F, a range in kT of ~1 Cal/YB. Insight into these physical quantities underlying thermal equilibration may prove useful for budding scientists, as well as the general public, in years ahead.

  2. Mobile contingency unit

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Sergio O. da; Magalhaes, Milton P. de [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil); Junqueira, Rodrigo A.; Torres, Carlos A.R. [PETROBRAS Transporte S/A (TRANSPETRO), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    This paper is aimed at presenting what is already a reality in TRANSPETRO in the area covered by OSBRA, a pipeline that carries by-products to the Mid-West region of Brazil. In order to meet the needs of covering occasional accidents, TRANSPETRO counts on a standardized system of emergency management. It is a great challenge to secure an efficient communication along the 964 km of extension, considering that there are shadow zones where it is not possible to use conventional means of communication such as mobile telephony and internet. It was in this context that the Mobile Contingency Unit Via Satellite - MCU was developed, to extend the communication facilities existing in fixed installations to remote places, mainly the pipeline right of ways. In case of emergency, simulation and work in the pipeline right of way, MCU is fully able to provide the same data, voice, closed-circuit TV and satellite video conference facilities that are available in any internal area of the PETROBRAS system. (author)

  3. Portable Virtual Training Units

    Science.gov (United States)

    Malone, Reagan; Johnston, Alan

    2015-01-01

    The Mission Operations Lab initiated a project to design, develop, deliver, test, and validate a unique training system for astronaut and ground support personnel. In an effort to keep training costs low, virtual training units (VTUs) have been designed based on images of actual hardware and manipulated by a touch screen style interface for ground support personnel training. This project helped modernized the training system and materials by integrating them with mobile devices for training when operators or crew are unavailable to physically train in the facility. This project also tested the concept of a handheld remote device to control integrated trainers using International Space Station (ISS) training simulators as a platform. The portable VTU can interface with the full-sized VTU, allowing a trainer co-located with a trainee to remotely manipulate a VTU and evaluate a trainee's response. This project helped determine if it is useful, cost effective, and beneficial for the instructor to have a portable handheld device to control the behavior of the models during training. This project has advanced NASA Marshall Space Flight Center's (MSFC's) VTU capabilities with modern and relevant technology to support space flight training needs of today and tomorrow.

  4. Cohesion in Multinational Military Units

    Science.gov (United States)

    2010-12-10

    He openly admitted his homosexual orientation at a staff meeting; by doing that he clearly stated his guidelines toward gays . He had developed a...of units and consequentially unit effectiveness (Dupuy 1993, 2948). Some nations permit openly gay and lesbian personnel and others may not. Social...may cause less tension. However, for some nations involvement of gays and lesbians in multinational units may be offensive, while other nations are

  5. Inlet Geomorphology Evolution Work Unit

    Science.gov (United States)

    2015-10-30

    the expected behavior and benefits of nearshore placement. Nearshore placement studies have been documented in two journal papers, one technical...Coastal Inlets Research Program Inlet Geomorphology Evolution Work Unit The Inlet Geomorphology Evolution work unit of the CIRP develops methods...sensing measurements, and USACE projects to create valuable guidance that address geomorphic questions. The present focus of the work unit is a common

  6. 基于MEMS陀螺的低成本捷联惯导系统设计%Design of Low-cost Inertial Navigation System Based on MEMS Gyroscope

    Institute of Scientific and Technical Information of China (English)

    何海洋; 王章波

    2014-01-01

    A low-cost strapdown inertial navigation system based on MEMS gyroscope and quartzose flexible accelerometer was designed and implemented. Static model equations of IMU were provided. The real-time compensation was completed between -40℃ and +60℃. As for the system, the method of quaternion is used for attitude calculation, and the velocity and position of a carrier are confirmed by coordinate transforma-tion and integral operation. The operation result of 60 seconds static test shows that IMU short-term precision is high, and it can meet the require-ment of SINS/GPS integrated navigation system.%介绍了一种基于MEMS陀螺和石英挠性加速度计的低成本捷联惯性导航系统的设计与实现方法。给出了惯性测量单元( IMU)的模型方程,并在全温下对IMU的输出进行补偿;采用“四元数”法进行姿态计算,通过坐标变换、积分运算确定载体的速度、位置;对惯测样机进行了60 s的静态测试,结果表明该系统短期准确度满足SINS/GPS组合导航系统需求。

  7. From stroke unit care to stroke care unit

    NARCIS (Netherlands)

    De Keyser, J; Sulter, G.

    1999-01-01

    In some stroke units continuous monitoring of blood pressure, electrocardiogram, body temperature, and oxygen saturation has become an integral part of the management of acute stroke. In addition, regular measurements of blood glucose are performed. Stroke units equipped with such monitoring facilit

  8. From stroke unit care to stroke care unit

    NARCIS (Netherlands)

    De Keyser, J; Sulter, G.

    1999-01-01

    In some stroke units continuous monitoring of blood pressure, electrocardiogram, body temperature, and oxygen saturation has become an integral part of the management of acute stroke. In addition, regular measurements of blood glucose are performed. Stroke units equipped with such monitoring

  9. GPS Metric Tracking Unit

    Science.gov (United States)

    2008-01-01

    As Global Positioning Satellite (GPS) applications become more prevalent for land- and air-based vehicles, GPS applications for space vehicles will also increase. The Applied Technology Directorate of Kennedy Space Center (KSC) has developed a lightweight, low-cost GPS Metric Tracking Unit (GMTU), the first of two steps in developing a lightweight, low-cost Space-Based Tracking and Command Subsystem (STACS) designed to meet Range Safety's link margin and latency requirements for vehicle command and telemetry data. The goals of STACS are to improve Range Safety operations and expand tracking capabilities for space vehicles. STACS will track the vehicle, receive commands, and send telemetry data through the space-based asset, which will dramatically reduce dependence on ground-based assets. The other step was the Low-Cost Tracking and Data Relay Satellite System (TDRSS) Transceiver (LCT2), developed by the Wallops Flight Facility (WFF), which allows the vehicle to communicate with a geosynchronous relay satellite. Although the GMTU and LCT2 were independently implemented and tested, the design collaboration of KSC and WFF engineers allowed GMTU and LCT2 to be integrated into one enclosure, leading to the final STACS. In operation, GMTU needs only a radio frequency (RF) input from a GPS antenna and outputs position and velocity data to the vehicle through a serial or pulse code modulation (PCM) interface. GMTU includes one commercial GPS receiver board and a custom board, the Command and Telemetry Processor (CTP) developed by KSC. The CTP design is based on a field-programmable gate array (FPGA) with embedded processors to support GPS functions.

  10. A comparison of instrumentation methods to estimate thoracolumbar motion in field-based occupational studies.

    Science.gov (United States)

    Schall, Mark C; Fethke, Nathan B; Chen, Howard; Gerr, Fred

    2015-05-01

    The performance of an inertial measurement unit (IMU) system for directly measuring thoracolumbar trunk motion was compared to that of the Lumbar Motion Monitor (LMM). Thirty-six male participants completed a simulated material handling task with both systems deployed simultaneously. Estimates of thoracolumbar trunk motion obtained with the IMU system were processed using five common methods for estimating trunk motion characteristics. Results of measurements obtained from IMUs secured to the sternum and pelvis had smaller root-mean-square differences and mean bias estimates in comparison to results obtained with the LMM than results of measurements obtained solely from a sternum mounted IMU. Fusion of IMU accelerometer measurements with IMU gyroscope and/or magnetometer measurements was observed to increase comparability to the LMM. Results suggest investigators should consider computing thoracolumbar trunk motion as a function of estimates from multiple IMUs using fusion algorithms rather than using a single accelerometer secured to the sternum in field-based studies.

  11. Ad valorem versus unit taxes

    DEFF Research Database (Denmark)

    Schröder, Philipp J.H.; Sørensen, Allan

    2010-01-01

    a general equilibrium monopolistic competition model with heterogeneous firms and intra-industry reallocations. We show that the welfare superiority of ad valorem over unit taxes under imperfect competition is not only preserved but amplified. The additional difference between the tools arises because unit...

  12. Fatigue of Concrete Armour Units

    DEFF Research Database (Denmark)

    Sørensen, N. B.; Burcharth, H. F.; Liu, Z.

    1995-01-01

    In the present article fatigue as a possible reason for failure of Dolosse armour units made of plain concrete is discussed.......In the present article fatigue as a possible reason for failure of Dolosse armour units made of plain concrete is discussed....

  13. Multicultural Mini-Units. Elementary.

    Science.gov (United States)

    Flora, Sherrill B.

    The teaching mini-units in this teacher's guide are designed for use with elementary level students. Thematic study units are given for each of the following countries or continents: Africa, Australia, Brazil, Canada, China, England, France, Germany, Greece, India, Israel, Italy, Japan, Mexico, Netherlands, Russia, Spain, Sweden, Thailand, and the…

  14. Studying in the United Kingdom

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The United Kingdom is among the world leaders in recruiting international students.Joanna Burke,Cultural Counselor in the Cultural and Education Section of the British Embassy in China,recently spoke about international students,especially Chinese students in the United Kingdom,with Beijing Review reporter Wang Hairong.

  15. Fatigue of Concrete Armour Units

    DEFF Research Database (Denmark)

    Sørensen, N. B.; Burcharth, H. F.; Liu, Z.

    1995-01-01

    In the present article fatigue as a possible reason for failure of Dolosse armour units made of plain concrete is discussed.......In the present article fatigue as a possible reason for failure of Dolosse armour units made of plain concrete is discussed....

  16. Unit 03 - Introduction to Computers

    OpenAIRE

    Unit 74, CC in GIS; National Center for Geographic Information and Analysis

    1990-01-01

    This unit provides a brief introduction to computer hardware and software. It discusses binary notation, the ASCII coding system and hardware components including the central processing unit (CPU), memory, peripherals and storage media. Software including operating systems, word processors database packages, spreadsheets and statistical packages are briefly described.

  17. Multicultural Mini-Units. Elementary.

    Science.gov (United States)

    Flora, Sherrill B.

    The teaching mini-units in this teacher's guide are designed for use with elementary level students. Thematic study units are given for each of the following countries or continents: Africa, Australia, Brazil, Canada, China, England, France, Germany, Greece, India, Israel, Italy, Japan, Mexico, Netherlands, Russia, Spain, Sweden, Thailand, and the…

  18. Edison Home Community Study Unit.

    Science.gov (United States)

    Lee County School District, Ft. Myers, FL. Dept. of Environmental Education and Instructional Development Services.

    History is not merely events that occurred in the past. The past has influenced the present, as the present will influence the future. The purpose of this community study unit is to provide fourth grade students with an opportunity to investigate some of the history of Lee County, Florida. The unit's focus is on Thomas Edison, who built a home in…

  19. Views of Appalachia: Resource Unit.

    Science.gov (United States)

    Chafin, Shirley R.

    Designed to teach twelfth grade English honors students in Kentucky to think critically, to write creatively, to develop a better self-concept, and to stimulate appreciation and pride for Appalachian literature and culture, this 9-week resource unit features mini-units on (1) Man and His Values; (2) Death; (3) Prejudice; (4) Strip Mining; and (5)…

  20. A flight test of the strapdown airborne gravimeter SGA-WZ in Greenland

    DEFF Research Database (Denmark)

    Zhao, Lei; Forsberg, René; Wu, Meiping;

    2015-01-01

    An airborne gravimeter is one of the most important tools for gravity data collection over large areas with mGal accuracy and a spatial resolution of several kilometers. In August 2012, a flight test was carried out to determine the feasibility and to assess the accuracy of the new Chinese SGA-WZ...

  1. 7 CFR 1160.104 - United States.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true United States. 1160.104 Section 1160.104 Agriculture... Definitions § 1160.104 United States. United States means the 48 contiguous states in the continental United States and the District of Columbia, except that United States means the 50 states of the United......

  2. Design of Dolos Armour Units

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Zhou

    1993-01-01

    The slender, complex types of armour units, such as Tetrapods and Dolosse are widely used. Many of the recent failures are such rubble mound breakwaters revealed that there is an imbalance between strength (structural integrity) of the units and the hydraulic stability (resistance to displacements......) of the armour layers. The paper deals only with dolos armour and presents the first design diagrammes and formulae where stresses from static, quasistatic and impact loads are implemented as well as the hydraulic stability. The dolos is treated as a multi shape unit where the thickness can be adjusted...

  3. Geysers Unit 18

    Energy Technology Data Exchange (ETDEWEB)

    Finney, John P.

    1980-12-01

    likely. For all of its risk aversion, SDG&E still remains one of the best potential markets for any energy producer. A recent article in FORBES MAGAZINE found that SDG&E had the third highest price per kilowatt of any utility in the country--5.9{cents} per kilowatt hour for commercial customers. That was in March, 1980. Energy cost adjustment clause increases resulted in an average commercial price per kilowatt hour of 7.2{cents} in May. In July it is expected to climb to 9.2{cents}. SDG&E's rate territory continues to expand at the rate of 5% annually and it is located just over 100 miles from a major source of geothermal heat in the Imperial Valley. But today, SDG&E has no commercial geothermal heat or power purchase contracts with domestic producers. You may ask, ''Why not?'' With no incentive to spend its own money and with a high growth rate, what is SDG&E doing to obtain capacity for its existing and future customers? At the present time, most of SDG&E's capital expenditure for generation is going to the construction of San Onofre Units 2 and 3 , a nuclear project which has been under way for ten years and which is expected to start generating commercial power in 1982 and 1983. San Onofre 2 and 3 will add 440 MW of capacity from a reliable, proven generating technology to SDG&E's system.

  4. 惯性测量组合减振系统动力学分析及实验研究%Dynamics Analysis and Experimental Study of Vibration System in Inertial Measuring Unit

    Institute of Scientific and Technical Information of China (English)

    郑玲; 房占鹏

    2015-01-01

    目的 保证惯性测量组合(Inertial Measuring Unit,IMU)减振系统具有良好的减振性能.方法 建立测量组合的三维模型,为提高IMU的解耦率,调整IMU和支架的质心,使IMU的质心与4个隔振器的刚度中心基本重合.采用Mooney-Rivlin超弹性本构模型对橡胶隔振器的橡胶材料进行表征,并在此基础上建立IMU减振系统有限元模型,对IMU减振系统的频率响应和冲击响应进行分析,并对IMU减振系统进行振动和冲击试验.结果 通过调整IMU质心位置和支架结构,使各阶模态能量解耦率都在80%以上;通过频率响应仿真分析,IMU减振系统在X,Y,Z方向上放大倍数分别为3.072,3.12,3.17;通过冲击响应仿真分析,IMU减振系统响应最大幅值为70.1g.结论 通过实验验证了有限元模型的正确性和减振设计的有效性.

  5. Tax_Units_2011_Final

    Data.gov (United States)

    Kansas Data Access and Support Center — The Statewide GIS Tax Unit boundary file was created through a collaborative partnership between the State of Kansas Department of Revenue Property Valuation...

  6. Fundamental units: physics and metrology

    CERN Document Server

    Okun, Lev Borisovich

    2003-01-01

    The problem of fundamental units is discussed in the context of achievements of both theoretical physics and modern metrology. On one hand, due to fascinating accuracy of atomic clocks, the traditional macroscopic standards of metrology (second, metre, kilogram) are giving way to standards based on fundamental units of nature: velocity of light $c$ and quantum of action $h$. On the other hand, the poor precision of gravitational constant $G$, which is widely believed to define the ``cube of theories'' and the units of the future ``theory of everything'', does not allow to use $G$ as a fundamental dimensional constant in metrology. The electromagnetic units in SI are actually based on concepts of prerelativistic classical electrodynamics such as ether, electric permitivity and magnetic permeability of vacuum. Concluding remarks are devoted to terminological confusion which accompanies the progress in basic physics and metrology.

  7. Studying in the United Kingdom

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ Beijing Review:The United Kingdom has many top universities in the world. Could you please tell us how many inter-national students are enrolled in UK institutes of higher learning and how many are from China?

  8. Environmental Control Unit Harness Project

    Science.gov (United States)

    Oliva-Buisson, Yvette J.

    2014-01-01

    Testing four new Environmental Control Unit Harnesses for improved user comfort during SCAPE operations. Phase I, testing in a lab environment, Phase II will continue testing the best candidates in a field environment.

  9. Electronegativity Equalization with Pauling Units.

    Science.gov (United States)

    Bratsch, Steven G.

    1984-01-01

    Discusses electronegativity equalization using Pauling units. Although Pauling has qualitatively defined electronegativity as the power of an atom in a molecule to attract electrons to itself, Pauling electronegativities are treated in this paper as prebonded, isolated-atom quantities. (JN)

  10. Advancing Discrimination Performance by Integrating an Inertial Measurement Unit with a Handheld EMI Sensor

    Science.gov (United States)

    2012-07-01

    sensor head (bottom left) and the measured EMI data (bottom right). Spatial Trajectory EM I D ata and M odel Fit Sweep Pattern -1.0 -0.5 0.0 X (m) 0.6...using the grid template are stored electronically as collected on the Allegro data acquisition computer and downloaded via serial port to a notebook...output options ( serial lines, USB ports, etc.). A serial line is used to provide synchronization of the IMU data with the EM61 data. The serial line

  11. Decommissioning of an irradiation unit

    Energy Technology Data Exchange (ETDEWEB)

    Richards, A.G. [Radiation Protection and Safety Services, Univ. of Leeds, Leeds (United Kingdom)

    2000-05-01

    Distributed throughout hospital, research establishments in the United Kingdom and many other countries are Irradiation Units and Teletherapy machines used for either research purposes or treatment of patients for radiotherapy. These Irradiation Units and Teletherapy machines are loaded with radioactive sources of either Cobalt 60 or Caesium 137. The activity of these sources can range from 1 Terabecquerel up to 100 Terabecquerels or more. Where it is possible to load the radioactive sources without removal from the shielded container into a transport package which is suitable for transport decommissioning of a Teletherapy machine is not a major exercise. When the radioactive sources need to be unloaded from the Irradiation Unit or Teletherapy machine the potential exists for very high levels of radiation. The operation outlined in the paper involved the transfer from an Irradiation Unit to a transport package of two 3.25 Terabecquerel sources of Cobalt 60. The operation of the removal and transfer comes within the scope of the United Kingdom Ionising Radiation Regulations 1985 which were made following the Recommendations of the International Commission on Radiological Protection. This paper illustrates a safe method for this operation and how doses received can be kept within ALARA. (author)

  12. United Kingdom: Health System Review.

    Science.gov (United States)

    Cylus, Jonathan; Richardson, Erica; Findley, Lisa; Longley, Marcus; O'Neill, Ciaran; Steel, David

    2015-01-01

    This analysis of the United Kingdom health system reviews recent developments in organization and governance, health financing, health care provision, health reforms and health system performance. It provides an overview of how the national health services operate in the four nations that make up the United Kingdom, as responsibility for organizing health financing and services was devolved from 1997. With devolution, the health systems in the United Kingdom have diverged in the details of how services are organized and paid for, but all have maintained national health services which provide universal access to a comprehensive package of services that are mostly free at the point of use. These health services are predominantly financed from general taxation and 83.5% of total health expenditure in the United Kingdom came from public sources in 2013. Life expectancy has increased steadily across the United Kingdom, but health inequalities have proved stubbornly resistant to improvement, and the gap between the most deprived and the most privileged continues to widen, rather than close. The United Kingdom faces challenges going forward, including how to cope with the needs of an ageing population, how to manage populations with poor health behaviours and associated chronic conditions, how to meet patient expectations of access to the latest available medicines and technologies, and how to adapt a system that has limited resources to expand its workforce and infrastructural capacity so it can rise to these challenges.

  13. 75 FR 5373 - United States Mint

    Science.gov (United States)

    2010-02-02

    ... United States Mint ACTION: Notification of Pricing for 2010 United States Mint Presidential $1 Coin Proof Set. \\TM\\ SUMMARY: The United States Mint is announcing the price of the 2010 United States Mint Presidential $1 Coin Proof Set. The 2010 United States Mint Presidential $1 Coin Proof Set, featuring $1...

  14. 31 CFR 800.225 - United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 800.225 Section 800... TAKEOVERS BY FOREIGN PERSONS Definitions § 800.225 United States. The term United States or U.S. means the United States of America, the States of the United States, the District of Columbia, and any...

  15. A BASIC CAMERA UNIT FOR MEDICAL PHOTOGRAPHY.

    Science.gov (United States)

    SMIALOWSKI, A; CURRIE, D J

    1964-08-22

    A camera unit suitable for most medical photographic purposes is described. The unit comprises a single-lens reflex camera, an electronic flash unit and supplementary lenses. Simple instructions for use of th's basic unit are presented. The unit is entirely suitable for taking fine-quality photographs of most medical subjects by persons who have had little photographic training.

  16. Some Relationships among Unit Subsystem Characteristics, Unit Task Characteristics, and Unit Effectiveness

    Science.gov (United States)

    1988-10-01

    C.J. (1980) The behavoiral antd affective consequences of performance- relevant situational variables. Organizational Behavior and Human Performance...cies, practices, and procedures facilitate and/or inhibit organizational work unit effectiveness. This dissertation introduces an additional variable...people in an organizational work unit perform rather than a person. Roberts, lulin, and Rousseau (1978) provided an adaptation of Lewin’s work that

  17. Global Units modulo Circular Units : descent without Iwasawa's Main Conjecture

    CERN Document Server

    Belliard, Jean-Robert

    2009-01-01

    Iwasawa's classical asymptotical formula relates the orders of the $p$-parts $X_n$ of the ideal class groups along a $\\ZM_p$-extension $F_\\infty/F$ of a number field $F$, to Iwasawa structural invariants $\\la$ and $\\mu$ attached to the inverse limit $X_\\infty=\\limpro X_n$. It relies on "good" descent properties satisfied by $X_n$. If $F$ is abelian and $F_\\infty$ is cyclotomic it is known that the $p$-parts of the orders of the global units modulo circular units $U_n/C_n$ are asymptotically equivalent to the $p$-parts of the ideal class numbers. This suggests that these quotients $U_n/C_n$, so to speak unit class groups, satisfy also good descent properties. We show this directly, i.e. without using Iwasawa's Main Conjecture.

  18. Near Real-Time Dissemination of Geo-Referenced Imagery by an Enterprise Server

    Science.gov (United States)

    2006-06-01

    Figure 5. From left to right, the figure shows the digital camera, power converter board, IMU interface board, single board computer , and the BAE...Multisensor Inertial Measurement Unit (MIMU). The hard drive is positioned under the single board computer . In Figure 6 a drawing is shown of these...Inertial Measurement Unit.[7] The NIM is a customized board developed by NAVSYS that provides an adaptable interface between the IMU and single board computer through

  19. Unsupervised segmentation with dynamical units.

    Science.gov (United States)

    Rao, A Ravishankar; Cecchi, Guillermo A; Peck, Charles C; Kozloski, James R

    2008-01-01

    In this paper, we present a novel network to separate mixtures of inputs that have been previously learned. A significant capability of the network is that it segments the components of each input object that most contribute to its classification. The network consists of amplitude-phase units that can synchronize their dynamics, so that separation is determined by the amplitude of units in an output layer, and segmentation by phase similarity between input and output layer units. Learning is unsupervised and based on a Hebbian update, and the architecture is very simple. Moreover, efficient segmentation can be achieved even when there is considerable superposition of the inputs. The network dynamics are derived from an objective function that rewards sparse coding in the generalized amplitude-phase variables. We argue that this objective function can provide a possible formal interpretation of the binding problem and that the implementation of the network architecture and dynamics is biologically plausible.

  20. THOR Particle Processing Unit PPU

    Science.gov (United States)

    Federica Marcucci, Maria; Bruno, Roberto; Consolini, Giuseppe; D'Amicis, Raffaella; De Lauretis, Marcello; De Marco, Rossana; De Michelis, Paola; Francia, Patrizia; Laurenza, Monica; Materassi, Massimo; Vellante, Massimo; Valentini, Francesco

    2016-04-01

    Turbulence Heating ObserveR (THOR) is the first mission ever flown in space dedicated to plasma turbulence. On board THOR, data collected by the Turbulent Electron Analyser, the Ion Mass Spectrum analyser and the Cold Solar Wind ion analyser instruments will be processed by a common digital processor unit, the Particle Processing Unit (PPU). PPU architecture will be based on the state of the art space flight processors and will be fully redundant, in order to efficiently and safely handle the data from the numerous sensors of the instruments suite. The approach of a common processing unit for particle instruments is very important for the enabling of an efficient management for correlative plasma measurements, also facilitating interoperation with other instruments on the spacecraft. Moreover, it permits technical and programmatic synergies giving the possibility to optimize and save spacecraft resources.

  1. Ad valorem versus unit taxes

    DEFF Research Database (Denmark)

    Schröder, Philipp J.H.; Sørensen, Allan

    2010-01-01

    Real-world industries are composed from heterogeneous firms and substantial intra-industry reallocations take place, i.e. high productivity firms squeeze out low productivity firms. Previous tax-tool comparisons have not included these central forces of industry structure. This paper examines...... a general equilibrium monopolistic competition model with heterogeneous firms and intra-industry reallocations. We show that the welfare superiority of ad valorem over unit taxes under imperfect competition is not only preserved but amplified. The additional difference between the tools arises because unit...... taxes distort relative prices, which in turn reduces average industry productivity through reallocations (the survival and increased market share of lower productivity firms). Importantly, numerical solutions of the model reveal that the relative welfare loss from using the unit tax increases...

  2. Unit for cleaning drilling muds

    Energy Technology Data Exchange (ETDEWEB)

    Dorosh, M.M.; Dera, Ya.I.; Fesenko, M.M.; Makedonov, N.I.; Surkov, V.T.

    1983-01-01

    A design is proposed for a unit for cleaning drilling muds which includes a settling tank with input sleeve and a sleeve of the purified mud and hydrocyclones. In order to improve the effectiveness of the degree of purification, the unit is equipped with an ejector and sludge filter arranged under the settling tank in the form of a grid installed in the upper part of the settling tank and connected to the sleeve of purified mud, while the inlet sleeve is arranged tangentially. The proposed unit can operate during drilling with the use of muds on water and carbon bases. As a result of its use, the degree of purification of the drilling mud reaches 30-35%; there is an increase in mechanical drilling rate, the service life of the sand-separator and the silt separators and decrease in wear of the pump equipment.

  3. Unit Reconstitutions: Combat Stress as an Indicator of Unit Effectiveness

    Science.gov (United States)

    2014-06-13

    professional military education or writing for trade journals supplemented the brief “reconstitution renaissance ” with scholarly excursus. This literature...United Sates Army, neuropsychiatry in World War II, Vol. II, overseas theatres . Washington, DC: Government Printing Office. 60 Nash, William P. 2007

  4. Auto Body Repair. Supplementary Units. Instructor Key and Student Units.

    Science.gov (United States)

    Daniel, Linda; Muench, James F., Ed.

    These supplementary units are designed to help students with special needs learn and apply auto body repair skills. The material specifically supplements the Auto Body Repair Curriculum Guide (University of Missouri-Columbia 1988), and is intended for instructors serving the occupational needs of various categories of disadvantaged and handicapped…

  5. The Work Unit Information System

    Science.gov (United States)

    1990-03-01

    detl- il 𔃻’ 1hiLS. dIxam.rnt. no.y be- used in conjuctien with tlie video, or !sep1aTate’ly. 114. SUBJECT TERMS 1%. NUMLItH Of 01 AuLAS 12, yi N~I) I T...6145, (202) 274-6817, (AV) 284-6817. 1I 10. WINS AND INPUT WRAP-UP The Army Material Command has implemented its own PC-based work unit input system...extrusion and composite materials . An example of a contract search would be: Find all work units that relate to contract F33615-84-K-2458. An example

  6. AC410 Unit 9 Assignment

    OpenAIRE

    Laynebaril1

    2017-01-01

     AC410 Unit 9 Assignment Click Link Below To Buy: http://hwcampus.com/shop/ac410-unit-9-assignment/   18–29. The CPA firm of Carson & Boggs LLP is performing an internal control audit in accordance with PCAOB Standard No. 5. The partner in charge of the engagement has asked you to explain the process of determining which controls to test. Describe the process, presenting each of the links in this process and a short summary of how the auditors approach each of them. v ...

  7. Comparison Of Digital Radiographic Units

    Science.gov (United States)

    Wang, Yen

    1986-06-01

    A total PACS will be inevitable for radiology practice within several years. To achieve a total PACS for radiology, a satisfactory digital radiographic unit is required, because approximately 65% of digital data for PACS comes from digital radiographs. There are several possibilities for producing digital radiographs, and 3 - 4 companies have been marketing digital radiographic devices. Some data regarding the digital radiographic units on the market are compared. It will aid in assessing the current status and availability of this aspect of development, as well as providing a summary of further development of digital radiographic technology.

  8. On the Unit of Translation

    Institute of Scientific and Technical Information of China (English)

    张曼

    2013-01-01

      The unit of translation has been the focus of debate through the history of translation. Barkhudarov suggests six levels of UT, each level could serve as unit of different levels of translation. Many Chinese translators also expressed their opinions on this issue, but there is no settled answer yet. This paper tends to make a distinction between different texts:ordinary and special. Ordinary ones can adopt the UT of paragraph, while special ones should adopt special UTs according to their own characteristics.

  9. Photovoltaic mounting/demounting unit

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to a photovoltaic arrangement comprising a photovoltaic assembly comprising a support structure defining a mounting surface onto which a photovoltaic module is detachably mounted; and a mounting/demounting unit comprising at least one mounting/demounting apparatus...... which when the mounting/demounting unit is moved along the mounting surface, causes the photovoltaic module to be mounted or demounted to the support structure; wherein the photovoltaic module comprises a carrier foil and wherein a total thickness of the photo voltaic module is below 500 muiotaeta....... The present invention further relates to an associated method for mounting/demounting photovoltaic modules....

  10. "Mexico in Transition." Curriculum Units.

    Science.gov (United States)

    Oregon Univ., Eugene. Foreign Language Resource Center.

    These curriculum units were developed in a National Endowment for the Humanities 1994 summer seminar "Mexico in Transition." The 23 lessons are written in Spanish. Lessons are entitled: (1) "La Migracion Mexicana Vista a Traves del Cuento 'Paso del Norte' de Juan Rulfo" (Jose Jorge Armendariz); (2) "Los Grupos Indigenas de…

  11. Dimensionality and the sample unit

    Science.gov (United States)

    Francis A. Roesch

    2009-01-01

    The sample unit and its implications for the Forest Service, U.S. Department of Agriculture's Forest Inventory and Analysis program are discussed in light of a generalized three-dimensional concept of continuous forest inventories. The concept views the sampled population as a spatial-temporal cube and the sample as a finite partitioning of the cube. The sample...

  12. Semasiological measurements of phraseological units

    Directory of Open Access Journals (Sweden)

    Khavpacheva Oksana Khautievna

    2015-06-01

    Full Text Available The article deals with semantic relations in phraseology in modern English. In particular, the authors attempt to analyze different perspectives on the problem of correlation of concepts such as phraseological variance and synonyms existing in Russian linguistics. In addition, the article reviews and analyzes the nature and mechanism of phraseological variance. Particular attention is paid to the criteria of a particular phraseological unit to variants or synonyms. It substantiates the idea that the most suitable for the modern English language seems the point of view that considers the variance of phraseological unit as a fixed rate of transformation of the language of this unit does not violate its semantic identity. The main content of the study is an analysis of the main types of options phraseological units of modern English language: the structural and grammatical (morphological, syntactic, lexical, lexical and stylistic and of quantitative. The article also examines the characteristics of phraseological synonyms that unlike phraseological variants are built on different images, different logical-conceptual and shades of meaning, scope and use of stylistic coloring.

  13. Compiler validates units and dimensions

    Science.gov (United States)

    Levine, F. E.

    1980-01-01

    Software added to compiler for automated test system for Space Shuttle decreases computer run errors by providing offline validation of engineering units used system command programs. Validation procedures are general, though originally written for GOAL, a free-form language that accepts "English-like" statements, and may be adapted to other programming languages.

  14. Education in the United States

    Institute of Scientific and Technical Information of China (English)

    钱富奎

    2009-01-01

    As might be expected,educational institutions in the United States reflect the nation's basic values,especially the ideal of equality of opportunity.From elementary school through college,Americans believe that everyone deserves an equal opportunity to get a good education.

  15. Unit 23 - History of GIS

    OpenAIRE

    Unit 55, CC in GIS; National Center for Geographic Information and Analysis

    1990-01-01

    This unit provides a very brief review of some important milestones in the development of GIS. It provides early examples of spatial analysis performed with multiple theme maps, then introduces people, applications and systems that were significant in the early days of computerized cartography and spatial analysis.

  16. Professional Cosmetology Practices. Instructional Units.

    Science.gov (United States)

    Hopcus, Sharron; Armstrong, Ivan J.

    This publication is designed to assist the instructor and students in understanding the latest concepts and techniques of the instructional phase of cosmetology programs. The instructional units are in five areas: (1) orientation, (2) professional practices: hair, (3) professional practices: skin and nails, (4) cosmetology science, and (5)…

  17. Tractor Safety. Unit A-9.

    Science.gov (United States)

    Luft, Vernon D.; Backlund, Paul

    This document is a teacher's guide for a unit in tractor and machinery safety for college freshmen. It is intended to be used for 10 hours of instruction for freshmen who are intending to work on or around machinery. Safety hazards directly and indirectly related to many types of machinery are covered in addition to tractors. The objectives of the…

  18. Solar Renewable Energy. Teaching Unit.

    Science.gov (United States)

    Buchanan, Marion; And Others

    This unit develops the concept of solar energy as a renewable resource. It includes: (1) an introductory section (developing understandings of photosynthesis and impact of solar energy); (2) information on solar energy use (including applications and geographic limitations of solar energy use); and (3) future considerations of solar energy…

  19. Trip Report United Arab Emirates

    Energy Technology Data Exchange (ETDEWEB)

    Nakanishi, K; Rodgers, A

    2004-10-06

    Keith Nakanishi and Arthur Rodgers traveled to the United Arab Emirates in February, 2004 to continue an on-going technical collaboration with UAE University and to service the two temporary LLNL seismic stations. Nakanishi and Rodgers then participated in the Gulf Seismic Forum, which was organized by LLNL and sponsored by the University of Sharjah.

  20. "Mexico in Transition." Curriculum Units.

    Science.gov (United States)

    Oregon Univ., Eugene. Foreign Language Resource Center.

    These curriculum units were developed in a National Endowment for the Humanities 1994 summer seminar "Mexico in Transition." The 23 lessons are written in Spanish. Lessons are entitled: (1) "La Migracion Mexicana Vista a Traves del Cuento 'Paso del Norte' de Juan Rulfo" (Jose Jorge Armendariz); (2) "Los Grupos Indigenas de Mexico: Condiciones…

  1. United States Navy DL Perspective

    Science.gov (United States)

    2010-08-10

    United States Navy DL Perspective CAPT Hank Reeves Navy eLearning Project Director 10 August 2010 Report Documentation Page Form ApprovedOMB No...Marine Corps (USMC) Navy eLearning Ongoing Shared with USMC, Coast Guard 9 NeL Help Site https://ile-help.nko.navy.mil/ile/ https://s-ile

  2. "Mexico in Transition." Curriculum Units.

    Science.gov (United States)

    Oregon Univ., Eugene. Foreign Language Resource Center.

    These curriculum units were developed in a National Endowment for the Humanities 1994 summer seminar "Mexico in Transition." The 23 lessons are written in Spanish. Lessons are entitled: (1) "La Migracion Mexicana Vista a Traves del Cuento 'Paso del Norte' de Juan Rulfo" (Jose Jorge Armendariz); (2) "Los Grupos Indigenas de…

  3. Norovirus in the United States

    Centers for Disease Control (CDC) Podcasts

    2013-09-09

    Dr. Aron Hall, a CDC epidemiologist specializing in norovirus, discusses the impact of norovirus in the United States.  Created: 9/9/2013 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 9/17/2013.

  4. Cholera in the United States

    Centers for Disease Control (CDC) Podcasts

    2011-11-08

    Anna Newton, Surveillance Epidemiologist at CDC, discusses cholera that was brought to the United States during an outbreak in Haiti and the Dominican Republic (Hispaniola).  Created: 11/8/2011 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 11/8/2011.

  5. 75 FR 25925 - United States Mint

    Science.gov (United States)

    2010-05-10

    ... United States Mint ACTION: Notification of Citizens Coinage Advisory Committee May 25, 2010 Public Meeting. SUMMARY: Pursuant to United States Code, Title 31, section 5135(b)(8)(C), the United States Mint...: May 25, 2010. Time: 9 a.m. to 12 p.m. Location: 8th Floor Board Room, United States Mint, 801...

  6. 31 CFR 560.307 - United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 560.307 Section 560.307 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... § 560.307 United States. The term United States means the United States, including its territories...

  7. 31 CFR 547.310 - United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 547.310 Section 547.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... General Definitions § 547.310 United States. The term United States means the United States,...

  8. 7 CFR 1250.308 - United States.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1250.308 Section 1250.308 Agriculture... Research and Promotion Order Definitions § 1250.308 United States. United States means the 48 contiguous States of the United States of America and the District of Columbia....

  9. 31 CFR 548.310 - United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 548.310 Section 548.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF....310 United States. The term United States means the United States, its territories and...

  10. 31 CFR 586.318 - United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 586.318 Section 586...) KOSOVO SANCTIONS REGULATIONS General Definitions § 586.318 United States. The term United States means the United States, its territories and possessions, and all areas under the jurisdiction or...

  11. 7 CFR 1212.31 - United States.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1212.31 Section 1212.31 Agriculture..., Consumer Education, and Industry Information Order Definitions § 1212.31 United States. “United States... territories and possessions of the United States....

  12. 31 CFR 543.310 - United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 543.310 Section 543.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... Definitions § 543.310 United States. The term United States means the United States, its territories...

  13. 31 CFR 592.311 - United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 592.311 Section 592... § 592.311 United States. The term United States, when used in the geographic sense, means the several States, the District of Columbia, and any commonwealth, territory, or possession of the United States....

  14. 31 CFR 546.310 - United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 546.310 Section 546.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF....310 United States. The term United States means the United States, its territories and...

  15. 31 CFR 538.314 - United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 538.314 Section 538.314 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... § 538.314 United States. The term United States means the United States, its territories and...

  16. 7 CFR 1205.23 - United States.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1205.23 Section 1205.23 Agriculture... Procedures for Conduct of Sign-up Period Definitions § 1205.23 United States. The term United States means the 50 states of the United States of America. Procedures...

  17. 31 CFR 594.313 - United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 594.313 Section 594.313 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... Definitions § 594.313 United States. The term United States means the United States, its territories...

  18. 31 CFR 588.310 - United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 588.310 Section 588.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... Definitions § 588.310 United States. The term United States means the United States, its territories...

  19. 7 CFR 1205.313 - United States.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1205.313 Section 1205.313 Agriculture... Research and Promotion Order Definitions § 1205.313 United States. United States means the 50 States of the United States of America....

  20. 31 CFR 593.311 - United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 593.311 Section 593.311 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... REGULATIONS General Definitions § 593.311 United States. The term United States means the United States,...