Design of Embedded Data Acquisition and Processing System of MEMS-INS
|School||Jiangsu University of Science and Technology|
|Course||Mechanical Manufacturing and Automation|
|Keywords||MIMU synchronous data acquisition CAN wavelet denoising|
Inertial navigation technology uses the inertial measuring element to measure carriermotion parameters respect to inertial space which is ultimately be used to determine theattitude, velocity and position of the carrier parameters and it has been widely used in thefields of aerospace and navigation. MIMU (Micro Inertial Measurement Unit) as a specialkind of combination MEMS inertial sensor device with its characteristics of low cost, smallsize, has been more and more used in inertial navigation system and has generated a newgeneration of the micro inertial navigation system.The measurement data of MIMU as thenavigation raw data has a critical influence on navigation accuracy while MIMU existshortcomings of poor accuracy and poor stability and therefore limit the applications in thehigh precision navigation.Due to single MIMU micro inertial navigation system beingdifficult to meet the requirements of modern navigation accuracy, This topic is in order toimprove the accuracy of the micro inertial navigation system through the study of multipleMIMU network, data synchronization acquisition and processing technology and using highprecision master inertial navigation system to the micro inertial navigation system forregular correction, which has important practical significance in the study of how to developthe MIMU in high precision navigation applications.In this paper, due to poor accuracy of single MIMU, a multi channel MIMU dataacquisition system is designed based on CAN bus in order to provide a real-time true andreliable data source for subsequent data integration. The data acquisition system consists ofdata acquisition modules, time reference module, data management module and IPC-sidereceiver module. The time reference module is to ensure the synchronization of the dataacquisition;485master-slave communications is used between data management moduleand data acquisition modules to ensure the orderly running of multiple nsor data; CANcommunication is used between the data management module and IPC end receivermodules to ensure high reliability and stability of the communication.. Altium designer isused to design PCB of each module, C51language is used for program design of MCUwhich mainly to realize232,485,CAN communication function and data pre-processingfunctions, MFC is used to interface of IPC and mainly finishded CAN communication, dataseparation, processing and display functions.Finally, the results of the debugging of hardware and software of various modules areintroduced and the error rate of network communication is tested. On this basis, the data of MIMU which is fixed on the turntable is collected and analysis: static,dynamic sensor dataare denoised and reconfigurated by Wavelet modulus maxima and wavelet threshold basedon wavelet denoising principle and the two denoising methods are evaluated and compared.The experimental results show that the hardware and software design scheme of theembedded MEMS-INS data acquisition and processing system is feasible;the reliability ofCAN network communication is higher, the multi MIMU data can be transmissed orderly ina CAN network and provide a reliable source of data to improve the micro inertial devicenavigation accuracy.