A new calibration and compensation method for installation errors of accelerometers in Gyroscope Free Strap-down Inertial Navigation System

The navigation accuracy is seriously affected by installation errors of accelerometers in Gyroscope Free Strap-down Inertial Navigation System(GFSINS). So, the installation errors have to be calibrated before used and the output errors of accelerometers must be compensated while GFSINS is on working. In this paper, consider a 12-accelerometer GFSINS constituted with four three-axis accelerometers, a new position error calibration method based on the invariance of a vector module value in different coordinates and a sensitive direction error calibration method based on the principle of coordinate transformation are proposed. And the position errors are calibrated first and then to calibrate the sensitive direction error with a same set of turntable experiment data. Against with the error calibration order, the sensitive direction errors are compensated first and the next is to compensate the position errors. The details of calibration and compensation algorithm are given in this paper. At last, these two algorithms are simulated and the simulation result shows that the calibration and compensation algorithms are useful and could compensate most accelerometers´ output errors caused by installation errors.