Design Of The Automatic Testing System For Micro Mechanical Gyro

With the large-scale mass production of the MEMS gyro, the cost of gyro is getting lower and lower.However,the test cycle of gyro’s performance is long, which makes the cost of gyro’s test relatively high and increases the gyro’s relative cost,it’s not conducive to promote the MEMS gyro. For this reason, an automatic testing system for the MEMS gyro is designed to improve the efficiency of testing and reduce the cost of testing.To solve the problem that batch micro gyroscopes are tested synchronously, the multi-channel data acquisition system is designed, which uses FPGA as the control chip to collect the data of 64 channels gyro and communicate with the host computer by USB.For the problem that installation error with batch micro gyroscopes fleetly installed on the tooling is relatively large, the method is designed to test the scale factor and the installation error, which bases on the testing principle of the gyro scale factor and the installation error decoupling, and gyro triaxial testing principle analysis, the influence on testing of other parameters can be least after the installation error is compensated.Aiming at the disadvantage of the conventional method to test scale factor temperature coefficient and bias temperature coefficient, the method is improved, it can reduce the interval between the test temperature, and improve the accuracy of scale factor temperature coefficient and bias temperature coefficient. Although the total test time increases, the number of gyro tested is voluminous, the relative cost of gyro testing is reduced. In addition, a method of fleetly calibrating is designed to gyro scale factor and bias which bases on the cross-correlation analysis of the gyro speed according to cosine function changes periodically, it can largely shorten the testing time.For the problem that the gyro scale factor and bias change markedly with different temperatures, by analyzing the basic principle of polynomial fitting, BP neural network and grey prediction model,compensation algorithm is used to reduce the influence of temperature changing on gyro scale factor and bias.Finally, the micro mechanical gyro testing experiment is conducted, the testingresult of the gyro triaxial testing and the method designed verify the feasibility of the designing test method; The test result of scale factor and bias under different temperatures, it has obtained the good compensation effect by using these three compensation algorithms.