High Precision Attitude Sensor And Calibration Research On Spatio-Temporal Unification Technology

As a high-performance attitude measurement instrument,attitude sensor has been widely used in industrial manufacturing,rehabilitation detection,space exploration and other fields.It is composed of inertial devices such as accelerometer and gyroscope,and its output data is obtained by the fusion of accelerometer and gyroscope.In this paper,the problems of spatial unity and time synchronization existed in the data fusion of accelerometer and gyroscope are studied in order to improve the dynamic output accuracy.The main research content of this paper includes the following aspects:1.In order to solve the problem of spatial unity in the calibration of the attitude sensor,the body coordinate system of the attitude sensor is determined first,and the accelerometer and gyroscope coordinate system are unified with the body coordinate system by the quadruple method.Secondly,aiming at the error caused by the installation of the measuring element,the24-position calibration method and multi-angle calibration method of the accelerometer and the positive and negative rotation calibration method of the gyroscope are designed to realize the spatial unity of the attitude sensor.2.In order to solve the problem of data error caused by asynchronism between accelerometer and gyroscope acquisition time.In this paper,a finite automatic state machine method based on time scheduling is proposed to solve the problem of asynchronization of acquisition time.The hardware adopts high speed single chip microcomputer,and two models of clock and stopwatch are used in time scheduling to improve the running speed of software.The finite automatic state machine adopts the function pointer method to reduce the time synchronization error and improve the accuracy of attitude fusion solution.3.In order to improve the dynamic output accuracy of the attitude sensor,the data fusion algorithm of the attitude sensor is studied.According to the high and low frequency error characteristics of accelerometer and gyroscope,the attitude fusion is solved by Mahony complementary filter.Aiming at the problem that the fusion data accuracy is not high due to the gyroscope noise ignored by the Mahony complementary filter,a gyroscope and acceleration output model with error estimation is designed and the fusion is solved by using the extended Kalman filter algorithm.Simulation results show that the attitude solving error of EKF fusion algorithm with noise estimation is smaller and more reliable.4.In order to verify the space unification technology and time synchronization technology in calibration,the static calibration equipment of accelerometer and dynamic calibration equipment of gyroscope are designed.According to the required function indexes in the calibration method,the overall scheme of the attitude sensor calibration device is proposed,and the mechanical structure and circuit of the attitude sensor calibration device are designed.Secondly,the system software architecture is designed,and the software design of the main controller and host computer modules is completed.The experiment shows that the calibration method studied in this paper can effectively improve the measurement accuracy of the attitude sensor,so that the accuracy of the attitude sensor can meet the factory requirements.