Research on Calibration Method of MEMS Gyroscope Mounting Error Based on Large-Range Autocollimator

A calibration and measurement method based on an autocollimator and a manual turntable are proposed to calibrate the mounting error of a three-axis microelectromechanical system (MEMS) gyroscope in a wearable inertial measurement unit (IMU). In this system, with the extension of the angle range of the autocollimator to ±9° and setting the mutual orthogonal structure of the two autocollimators, the measurement angle range of the MEMS gyroscope mounting error and the evaluation reference of the three-axis attitude angle data are obtained, respectively, and the common data acquisition serial port between the autocollimator camera and the IMU host computer is built. As a result, the acquisition time is synchronized between the two systems. Additionally, the angular rate reading value of the MEMS gyroscope is integrated by time to unify the reading value scale between the calibration system and the MEMS gyroscope. This method is further compared with the traditional precision three-axis angular rate output turntable calibration method, and the accuracy deviation of the MEMS gyroscope mounting error after calibration is less than 0.3%. This method helps facilitate the development of inertial sensing calibration techniques toward traceability, which significantly reduces and simplifies laboratory equipment costs and maintenance requirements.