Design And Realization Of Vehicle Attitude Measurement System Based On ARM

The data about vehicle attitude are significant parameters for vehicle control, of which the method and accuracy in survey are closely related to the measurement system's performance and cost. With the development of novel sensor and ARM microprocessor, the geomagnetic field and gravity field-based strapdown Attitude Measurement System, which is composed of accelerometer, magnetoresistive sensor and ARM microprocessor, has been used as the first choice for Carrier Attitude Measurement. In addition, the Attitude Measurement System has been widely applied in areas such as geographical exploration, oil drilling platform and robot control.This thesis aims to design an ARM microprocessor-based Attitude Measurement System. Under the prerequisite of the volume, cost and real time, the accurate measurement of carrier attitude angles can be realized by this Attitude Measurement System. This system, integrated by the 3-axis magnetoresistive sensor HMC1021/1022 of Honeywell and 2-axis accelerator ADXL202 of AD and S3C44B0X ARM7 microprocessor, tries to build up strapdown Attitude Measurement System. The signals of geomagnetic field and gravity field are received by the magnetoresistive sensor and accelerator respectively. After signal processing and error compensation, the attitude angles are calculated by the microprocessor. Finally, the results are displayed on LCD or outputted to PC via serial communication interface, so as to realize the accurate and real-time measurement of attitude angle.This thesis mainly introduces the theory of Attitude Measurement based on signals of geomagnetic field and gravity field, and deduces the mathematical model of heading, pitch and roll. The thesis completes the design and test of the hardware circuit of Attitude Measurement System, working out various systematic software design including transplantation of uC/OS-II Operating system, acceleration data acquisition, geomagnetic field data acquisition, and calculation of the attitude angles. In the end it gives out the error analysis of system measurement results and introduces algorithms such as digital filter and ellipse correction to compensating errors.