Calibration And Application Of Inertial Measurement Unit Based On MEMS Gyro

In aerospace, precision instruments, biology, medical care and other fields,the inertial measurement unit(IMU) based on MEMS(Micro Electronic Mechanical System) inertial sensor have broad application potential with the characteristics of small size,long service life,impact resistance and high reliability.Many countries pay high attention to it,and it is listed as one of the critical technologies of inertia in the 21st century.The research content are testing of MEMS gyro,calibration of the inertial measurement unit and research on gyro random model and a kind of attitude measuring system in this paper.As MEMS technology continues to mature,MEMS gyro have the tendency to replace low or intermediate precision of fiber optic gyro.The performance of STIM202 gyro is firstly tested in this paper,the performance mainly include scaling factor, scaling factor nonlinear, zero drift,zero drift stability and zero drift repeatability.And then, the inertial measurement unit based on high precision STIM202 gyro is calibrated.A kind of effective temperature compensating measures significant particularly important,because of the temperature effect of MEMS gyro is quite obvious.The error model of gyro and accelerometer is defined in this paper,in the temperature range from -40℃to70℃,the calibration of gyro and accelerometer are done at the same time while calibrating the inertial measurement unit,the method can save a lot of time without losing the accuracy and make mass production to become possible.The random noise of MEMS gyro seriously influence the gyro's accuracy,the main noise are quantization noise,angle random-walking,drift instability,rate random-walking and rate slope. Firstly,the noise source are analysised with the methods of Allan variance to evaluate the performance of the gyro, and then the kalman filter is designed based on the time series model established,and this model can effectively filter the noise through using the kalman filter, Finally,the filtered gyro noise source are analysised with the methods of Allan variance.In the experiment of driving car,the contrast test of vertical gyroscope and laser inertial navigation system show that the vertical gyroscope can attain the certain accuracy and can meet the low precision areas of application.Finally,the full work of the paper is summarized and the future research content on this subject is made predicted.