Research And Implementation Of Attitude Measurement System Based On MEMS Sensors

With the development of microelectronics technology, micro-electrical mechanical systems (MEMS) are widely used in the area of measurement due to the advantages of small size, light weight, low cost, low power and wide dynamic range. In this paper, an implementation of attitude measurement system based on MEMS inertial sensors is proposed, which can achieve attitude control of the carrier by collecting the data of sensors.Firstly, the principles of strapdown attitude measurement system are introduced, including the definition of inertial coordinate systems, establishment and update of attitude matrix and the method of initial alignment system. The quaternion method and the three-like equivalent rotation vector method which apply to different motion states are discussed in detail.Secondly, the error models of gyroscope and accelerometer are established through the performance analysis of micro-mechanical inertial sensors. Then based on the accuracy and cost requirements of system, sensor ADIS16355 is chosen as the Inertial Measurement Unit (IMU). In view of the gyro drift is the major factor in causing systematic errors, a wavelet de-noise technique is implied to the gyro's output signal and the appropriate wavelet parameters are specified.The paper proposes an implementation program of attitude measurement system based on MEMS sensors. The system hardware is consisted of data acquisition module, processor module, RS-485 interface module and the external auxiliary module. In addition, the processor module can achieve the software functions such as signal processing and attitude calculation with STM32F103RBT6 as the CPU.Finally, the hardware and software are integrated into an embedded attitude measurement system which can run independently after debagging. The experiments are designed to validate the system functions of data acquisition, initial alignment and attitude calculation. The results prove that the system can work effectively and the performance can meet the design requirement. The attitude system based on MEMS has a certain appliance value as a result of its characteristics in compact structure, low price ,real-time response and so on.