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Research on in-light alignment error model based on quaternion and rotation vector

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Journal of Beijing Institute of Technology 2011年第3期20卷 331-338页

作者：徐国强孟秀云 School of Aerospace Engineering Beijing Institute of Technology

Euler angle error model, rotation vector error model （RVE） and quaternion error model （QE） were qualitatively and quantitatively compared and an in-flight alignment filter algorithm was designed. This algorithm used extended Kalman filter （EKF） based on RVE and QE separately avoi- ding the accuracy problem of the Euler angle model and used Rauch-Tung-Striebel（RTS） smoothing method to refine the accuracy recuperating the coning error for simplified RVE. Simulation results show that RVE and QE are more adapt for nonlinear filter estimation than the Euler angle model. The filter algorithm designed has more advantages in convergence speed, accuracy and stability comparing with the algorithm based on the three models separately.

关键词： error model quaternion in-flight alignment rotation vector

Ridge estimation iterative solution of ill-posed mixed additive and multiplicative random error model with equality constraints

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Geodesy and Geodynamics 2021年第5期12卷 336-346页

作者： Leyang Wang Tao Chen Faculty of Geomatics East China University of Technology330013NanchangChina

The reasonable prior information between the parameters in the adjustment processing can significantly improve the precision of the parameter solution. Based on the principle of equality constraints, we establish the mixed additive and multiplicative random error model with equality constraints and derive the weighted least squares iterative solution of the model. In addition, aiming at the ill-posed problem of the coefficient matrix, we also propose the ridge estimation iterative solution of ill-posed mixed additive and multiplicative random error model with equality constraints based on the principle of ridge estimation method and derive the U-curve method to determine the ridge parameter. The experimental results show that the weighted least squares iterative solution can obtain more reasonable parameter estimation and precision information than existing solutions, verifying the feasibility of applying the equality constraints to the mixed additive and multiplicative random error model. Furthermore, the ridge estimation iterative solution can obtain more accurate parameter estimation and precision information than the weighted least squares iterative solution.

关键词： Ill-posed problem Mixed additive and multiplicative random error model Equality constraints Weighted least squares Ridge estimation method U-curve method

Simulation of Current Measurement Using Magnetic Sensor Arrays and Its error model

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Computer Aided Drafting,Design and Manufacturing 2004年第1期14卷 48-53页

作者： WANGJing YAOJian-jun WANGJian-hua SchoolofElectricalEngineering Xi＇anJiaotongUniversityXi＇an710049China SchoolofElectricalEngineering Xi＇anJiaotongUniversityXi＇an710049China

Magnetic sensor arrays are proposed to measure electric current in a non-contact way. In order to achieve higher accuracy, signal processing techniques for magnetic sensor arrays are utilized. Simulation techniques are necessary to study the factors influencing the accuracy of current measurement. This paper presents a simulation method to estimate the impact of sensing area and position of sensors on the accuracy of current measurement. Several error models are built up to support computer-aided design of magnetic sensor arrays.

关键词： current measurement sensor arrays error model simulation

Research on error model of 9-Dof Motion System

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Research on Error Model of 9-Dof Motion System

Automatic modeling algorithm of stochastic error for inertial sensors

2011 Third Pacific-Asia Conference on Circuits, Communications and System

作者： Zhiyong Qu Zhengmao Ye School of Mechatronics Engineering Harbin Institute of Technology

Based on the basic principles of multi-body system kinematics, the topological structures and low-order body arrays of 9-dof motion system are expatiated. After the basic rules of system with error analyzed, the composing method of characteristic matrix is put forward. Besides the above, synthesis volumetric errors based on characteristic matrix are obtained. In the process of space rendezvous and docking, this method can better solve the error model of position and pose between target simulator and tracking simulator and offer academic reference for error synthesis error model and compensation.

关键词： 9-dof motion system Multi-body system Kinematics error model RVD

来源： cnki会议评论

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cnki会议

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Control Theory and Technology 2024年第1期22卷 81-91页

作者： Luodi Zhao Long Zhao School of Automation Science and Electrical Engineering Beihang UniversityBeijing100191China Digital Navigation Center Beihang UniversityBeijing100191China Science and Technology on Aircraft Control Laboratory Beihang UniversityBeijing100191China

This paper proposes an automatic algorithm to determine the properties of stochastic processes and their parameters for inertial error. The proposed approach is based on a recently developed method called the generalized method of wavelet moments (GMWM), whose estimator was proven to be consistent and asymptotically normally distributed. This algorithm is suitable mainly (but not only) for the combination of several stochastic processes, where the model identification and parameter estimation are quite difficult for the traditional methods, such as the Allan variance and the power spectral density analysis. This algorithm further explores the complete stochastic error models and the candidate model ranking criterion to realize automatic model identification and determination. The best model is selected by making the trade-off between the model accuracy and the model complexity. The validation of this approach is verified by practical examples of model selection for MEMS-IMUs (micro-electro-mechanical system inertial measurement units) in varying dynamic conditions.

关键词： GMWM Stochastic process Inertial sensor Sensor calibration error model Allan variance

A Numerical error modeling Method for Parallel Kinematic Machines and Its Applications

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维普期刊数据库

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Tsinghua Science and Technology 2010年第5期15卷 489-497页

作者：刘大炜王立平李铁民黄鹏 Institute of Manufacturing Engineering Department of Precision Instruments and Mechanology Tsinghua University

error model is the basis for accuracy-related computations and analyses for parallel kinematic machines（PKMs）.Traditional error modeling methods are usually based on differentiation of kinematic solutions,but the solving process is often complex and has limitations for certain specialized PKMs.A concise numerical error modeling method with the inverse kinematic solution as its only requirement is presented in this *** avoid complex Jacobian matrix computations,the difference matrix that can be quickly calculated by kinematic solutions was used to replace the differential *** quasi-Newton method,which has high speed and high precision,was introduced to solve the numerical forward kinematic *** verify the efficiency of this numerical error modeling method,three applications in error transformation matrix（ETM） modeling,error analysis,and kinematic calibration were simulated on a 4RRR PKM.A comparison with the results obtained by the traditional method shows that the numerical method is accurate,convenient,and has lower requirements and wider applicability,especially for certain specialized and manufactured PKMs.

关键词： error model difference matrix quasi-Newton method error transformation matrix(ETM) calibration

Calibration method of quartz accelerometer on dynamic centrifuge

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Chinese Journal of Aeronautics 2022年第6期35卷 262-272页

作者： Yingbo SUN Shunqing REN Changhong WANG School of Astronautics Harbin Institute of TechnologyHarbin 150001China

This paper proposes a novel method for calibrating error coefficients of the quartz accelerometer faster on the dynamic centrifuge,which can generate a continuous dynamic acceleration ***,working principle and structure of the dynamic centrifuge are analyzed,the error sources and the uncertainty of the dynamic centrifuge are expounded,and relevant coordinate systems are ***,according to the characteristics of the input specific forces and the propagating methods of the error sources,the accurate input specific forces acted on the input reference axes of accelerometer are *** on the calibration error model of the accelerometer,the corresponding dynamic calibration method is ***,the second-order and high-order coefficients of the acceleration error model are calibrated,and the calibration precision of the coefficients is *** with traditional calibration methods,the method proposed in this paper not only greatly enhances the calibration efficiency by reducing the installing positions of the accelerometer,but also separates the centrifuge errors from the outputs of the accelerometer,which improves the accuracy and efficiency of the calibration method simultaneously.

关键词： Accelerometer Calibration Dynamic centrifuge Dynamic excitation stimulus error model Homogeneous transformation

Design of a Two-Step Calibration Method of Kinematic Parameters for Serial Robots

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Chinese Journal of Mechanical Engineering 2017年第2期30卷 438-448页

作者： Wei WANG Lei WANG Chao YUN School of Mechanical Engineering and Automation Beihang University State Key Lab of Digital Manufacturing Equipment and Technology Huazhong University of Science and Technology

Serial robots are used to handle workpieces with large dimensions, and calibrating kinematic parameters is one of the most efficient ways to upgrade their accuracy. Many models are set up to investigate how many kinematic parameters can be identified to meet the minimal principle, but the base frame and the kinematic parameter are indistinctly calibrated in a one-step way. A two-step method of calibrating kinematic parameters is proposed to improve the accuracy of the robot＇s base frame and kinematic parameters. The forward kinematics described with respect to the measuring coordinate frame are established based on the product- of-exponential （POE） formula. In the first step the robot＇s base coordinate frame is calibrated by the unit quaternion form. The errors of both the robot＇s reference configuration and the base coordinate frame＇s pose are equivalently transformed to the zero-position errors of the robot＇s joints. The simplified model of the robot＇s positioning error is established in second-power explicit expressions. Then the identification model is finished by the least square method, requiring measuring position coordinates only. The complete subtasks of calibrating the robot＇ s 39 kinematic parameters are finished in the second step. It＇s proved by a group of calibration experiments that by the proposed two-step calibration method the average absolute accuracy of industrial robots is updated to 0.23 mm. This paper presents that the robot＇s base frame should be calibrated before its kinematic parameters in order to upgrade its absolute positioning accuracy.

关键词： Kinematic parameter Calibration error model Product of exponential Industrial robot

Motion error Compensation of Multi-legged Walking Robots

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Chinese Journal of Mechanical Engineering 2012年第4期25卷 639-646页

作者： WANG Liangwen CHEN Xuedong WANG Xinjie TANG Weigang SUN Yi PAN Chunmei State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and Technology Wuhan 430074 China Mechanical and Electrical Engineering Institute Zhengzhou University of Light Industry Zhengzhou 450002 China

Existing errors in the structure and kinematic parameters of multi-legged walking robots,the motion trajectory of robot will diverge from the ideal sports requirements in *** the existing error compensation is usually used for control compensation of manipulator arm,the error compensation of multi-legged robots has seldom been *** order to reduce the kinematic error of robots,a motion error compensation method based on the feedforward for multi-legged mobile robots is proposed to improve motion precision of a mobile *** locus error of a robot body is measured,when robot moves along a given *** of driven joint variables is obtained by error calculation model in terms of the locus error of robot *** value is used to compensate driven joint variables and modify control model of robot,which can drive the robots following control model *** model of the relation between robot＇s locus errors and kinematic variables errors is set up to achieve the kinematic error *** the basis of the inverse kinematics of a multi-legged walking robot,the relation between error of the motion trajectory and driven joint variables of robots is ***,the equation set is obtained,which expresses relation among error of driven joint variables,structure parameters and error of robot＇s *** MiniQuad as an example,when the robot MiniQuad moves following beeline tread,motion error compensation is *** actual locus errors of the robot body are measured before and after compensation in the *** to the test,variations of the actual coordinate value of the robot centroid in x-direction and z-direction are reduced more than one *** kinematic errors of robot body are reduced effectively by the use of the motion error compensation method based on the feedforward.

关键词： multi-legged walking robot error model motion error compensation kinematic analysis motion precision