The Error Compensation Of MEMS Sensor Of Inertial Navigation System

Strapdown inertial navigation system apply to all aspects of navigation because of its low cost, small size and other advantages, such as the unmanned helicopter, in the damage survey, aerial photography, transmission line testing. In general, strapdown inertial navigation system use small size inertial devices such as laser gyro, fiber optic gyro and inertial MEMS devices. Especially, inertial MEMS devices used widely in civilian navigation because of its very low price.But, inertial MEMS devices' precision are very lower than inertial level devices. We could get relative precision if doing error compensation accurate three-axis turntable, but cost is too expensive calibration before use.This article describes the principle of strapdown inertial navigation and the main source of error. Buliding error model for the inertial measurement unit consisting of MEMS gyroscope and accelerometer. In general, calibration is produce in the three-axis turntable that very precise. But accurate three-axis turntable is so too expensive that the average user can not accept. In this article, calibration process is based on gravity as the reference standard, coupled with more sophisticated home-made single-axis rotary table can be basically realized the error compensation of inertial MEMS devices.This article is divided into inertial error zero error, scale factor error and misalignment, and temperature drift, and calibration was carried out separately. Then the zero error and scale factor error of piecewise linear, a calculation of their zero per bit error and scale factor error. Temperature will affect the calibration results section, the paper points were seven-segment temperature and 40 were studied. Installation error is in the system, the situation of non-orthogonal. Inertial devices as the benchmark standard in turntable data collection, structure axis matrix, and the ideal orthogonal matrix divided by the installation of the sensor error matrix.This article design the automatic calibration based on the previous manual calibration, realize the automated production process by PC control, speeding the production process. As the equipment is simple, flexible operation, may well be applied to the field of civilian navigation.