检索结果-南通市图书馆

Automatic modeling algorithm of stochastic error for inertial sensors

在线全文

学校读者我要写书评

暂无评论

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

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

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

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

在线全文

学校读者我要写书评

暂无评论

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

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

在线全文

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

Research on Error Model of 9-Dof Motion System

Calibration method of quartz accelerometer on dynamic centrifuge

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

在线全文

cnki会议

学校读者我要写书评

暂无评论

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 excitation.Firstly,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 established.Then,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 obtained.Based on the calibration error model of the accelerometer,the corresponding dynamic calibration method is proposed.Finally,the second-order and high-order coefficients of the acceleration error model are calibrated,and the calibration precision of the coefficients is analyzed.Compared 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

An Intelligent Ellipsoid Calibration Method Based on the Grey Wolf Algorithm for Magnetic Compass

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2021年第2期18卷 453-461页

作者： Xusheng Lei Xiaoyu Zhang Yankun Hao School of the Instrumentation Science and Opto-Electronic Engineering Beihang UniversityBeijing 100191China

With the measurement of the Earth’s magnetic field,magnetic compass can provide high frequency heading information.However,it suffers from local magnetic interference.An intelligent ellipsoid calibration method based on the grey wolf is proposed to generate optimal parameters for magnetic compass to generate high performance heading information.With the analysis of the projection relationship among the navigation coordinate frame,the body frame and the local horizontal frame,the heading ellipsoid equation is constructed.Furthermore,an improved grey wolf algorithm is proposed to find optimization solution in a large solution space.With the improvement of the convergence factor and the evolutionary mechanism,the improved grey wolf algorithm can generate optimized solution for heading ellipsoid equation.The effectiveness of the proposed method has been verified by a series of vehicle and flight tests.The experimental results show that the proposed method can eliminate errors caused by sensor defects,hard-iron interference,and soft-iron interference effectively.The heading error generated by the magnetic compass is less than 0.2162 degree in real flight tests.

关键词： magnetic compass ellipsoid parameters grey wolf algorithm error model

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

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Design and Accuracy Analysis of a Metamorphic CNC Flame Cutting Machine for Ship Manufacturing

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2016年第5期29卷 930-943页

作者： HU Shenghai ZHANG Manhui ZHANG Baoping CHEN Xi YU Wei College of Mechanical and Electrical Engineering Harbin Engineering University

The current research of processing large size fabrication holes on complex spatial curved surface mainly focuses on the CNC flame cutting machines design for ship hull of ship manufacturing. However, the existing machines cannot meet the continuous cutting requirements with variable pass conditions through their fixed configuration, and cannot realize high-precision processing as the accuracy theory is not studied adequately. This paper deals with structure design and accuracy prediction technology of novel machine tools for solving the problem of continuous and high-precision cutting. The needed variable trajectory and variable pose kinematic characteristics of non-contact cutting tool are figured out and a metamorphic CNC flame cutting machine designed through metamorphic principle is presented. To analyze kinematic accuracy of the machine, models of joint clearances, manufacturing tolerances and errors in the input variables and error models considering the combined effects are derived based on screw theory after establishing ideal kinematic models. Numerical simulations, processing experiment and trajectory tracking experiment are conducted relative to an eccentric hole with bevels on cylindrical surface respectively. The results of cutting pass contour and kinematic error interval which the position error is from -0.975 mm to ＋0.628 mm and orientation error is from -0.01 rad to ＋0.01 rad indicate that the developed machine can complete cutting process continuously and effectively, and the established kinematic error models are effective although the interval is within a ＇large＇ range. It also shows the matching property between metamorphic principle and variable working tasks, and the mapping correlation between original designing parameters and kinematic errors of machines. This research develops a metamorphic CNC flame cutting machine and establishes kinematic error models for accuracy analysis of machine tools.

关键词： CNC cutting machine metamorphic principle accuracy analysis screw theory error model