Re-fusion of Inertial Attitude Measurement Sensors Based on Phase-lag-free LPF and Kalman Filter

The high-quality signal is the basis of motion control. Gyroscope is an important sensor in feedback loop of inertial stabilization control. However, accumulative errors exist in attitude calculation by gyroscope because of gyro drift. In general, Kalman filter is used as fusing the output of gyroscopes and accelerometers to suppress gyro drift. This method will bring phase lag deviation because it does not consider the change of angular acceleration in actual motion. Therefore, a re-fusion method based on phase-lag-free low pass filter(LPF) and Kalman filter is proposed. The simulation and experimental results show that the re-fusion method proposed in this paper integrates the output data of different sensors, which has obvious ability to suppress phase lag and has a certain filtering performance on the basis of suppressing gyro drift.