Design And Implementation Of Low-cost Attitude And Heading Reference System Based On Multi-sensor Combination

Under the background of promoting the application of intelligent technology to people’s daily life in our country,the research on civil consumer-level attitude and heading systems has been valued.The paper designs a low-cost attitude and heading measurement system that is used to achieve attitude information measurement of related intelligent operating equipment for agriculture、forestry or other living areas,and proposes an attitude measurement scheme combining nine-axis MEMS motion measurement units with GPS.The solution guarantees the measurement accuracy of the system under the premise of low cost.Firstly,the thesis exprounds the basic theories of the attitude and heading reference system.After comparing and analyzing several commonly used attitude updating algorithms,the quaternion method is selected to solve the system attitude.The configuration of three nine-axis MEMS motion measurement units are designed,and the data fusion methods of three gyroscopes are discussed emphatically.Based on the introduction of the Kalman filter algorithm,the data fusion algorithm of the combined system is derived.And the algorithm performance and the feasibility of its implementation in the system are analyzed by means of the simulation results.Secondly,the design of overall hardware scheme is given,and the detailed design of each module circuit is completed.In order to acheive the scalability of system multi-sensor data acquisition,the hardware structure of the microcontroller board,data communication board,and MEMS sensor unit circuit board is designed,and the system hardware debugging is accomplished.Then,in terms of software design,the overall system software design plan is given,and the ARM initialization module,MEMS sensor data acquisition module,GPS unit data acquisition and analysis module,data fusion and attitude solution module、software design of data storage module and Ethernet communication module are completed in blocks by using modular ideas.A communication attitude display interface based on QT serial port/network port is designed,which can display and save the attitude angle data in real time.Finally,the thesis accomplishes the module test and performance verification experiments of the system.The performance test results of the sensor data acquisition module,the test results of the Ethernet/serial communication module and the interface display function are given and analyzed.The static experiments and fixed-point swing experiment of the system is devised so as to complete system attitude measurement performance test.The system experiment results show that:the root mean square error of the attitude angle does not exceed 1~°in a static experimental environment.In a fixed-point swing experimental environment,the root mean square error of the pitch and roll angles is between 2.0~°,and the root mean square error of the heading angle does not exceed7.0~°.The attitude and heading system designed in this paper has preliminarily prossessed real-time stable attitude measurement capability.