Research Of Micro And Embedded Attitude And Heading Reference System Based On MEMS

Although the triditional Attutude and Heading Reference System (AHRS) provides a high level of precision, however, the high cost and a large size made it impossible to be used for the civil technologies but military fields. In more and more civil fields, the huge demand of this technology, such as the electronical toys, tridimensional emulation, sports detection, robots and VR games, a low-cost and micro AHRS can greatly benefit the technology development in these areas. With the rapid development of embedded system and the appearance of newly high-performed inertial components, it's possible to design a low-cost and micro AHRS. The paper researches a kind of AHRS which bases on Micro Electro Mechanical System (MEMS) and Digital Singal Processor (DSP). It characterizes low cost, small volume and higher precision.Firstly, the basic theories and operational principles of AHRS are introduced, including the definition of usually coordinates in inertia system, carrier's attitude denotation and coordinates conversion, basic equation and attitude equation in inertia system. Then elementarily expatiate the attitude algorithm. Quaternion algorithm is used to calculate the attitude matrix in this paper. Kalman filter algorithm is used to modify the attitude error of vibrational carrier.Secondly, the whole system design of AHRS based on MEMS is given in the paper. The system consists of sensor module, data collection module, DSP and periphery port, serial communication module and PC. The sensor module is composed by ADI's tri-axis inertial sensor ADIS16350 and Honeywell's tri-axis magnetometer HMC1021Z/1022. The data coolection module is mainly used to collect the sensor singal, magnify the singal, transmit the singal from Analog singal to Digital singal and restrain noise. DSP is used to calculate the attitude and heading. All attitude information are shown in the screen of PC through the serial communication port. Components selection, system block chart, circuit diagram, software algorithm flow chart and part of application programs are discussed in detail.Lastly, the software and hardware are integrated into an embedded DSP system which can singly works. Experiments are designed to validate the system. The result shows that the system can meet the requirement. The error of the system to some company's products is acceptable. AHRS which uses MEMS sensor for data collection unit and combines DSP for calculation and control, has compact structure, light weight, and lower price than conventional AHRS. It is also dependable and applicable to those fields which has low requirement of AHRS's precision.