Delay Compensation of Tilt Sensors Based on MEMS Accelerometer Using Data Fusion Technique

In this paper, the inaccuracies of the tilt sensor based on microelectromechanical systems accelerometer and gyroscope during the process of the angle measurement are considered, and a new method is proposed to compensate them, using data fusion of sensors. The tilt sensor has a constant delay and low bandwidth. In the gyroscope, drift phenomena makes some difficulties in the angle measurement. A model for the sensory system is developed and a modified Kalman filter is proposed to compensate the delay of the tilt sensor using the data fusion technique. A complementary filter is designed to overcome the problem of low bandwidth in the tilt sensor. The overall proposed sensor fusion consists of a complementary filter as a prefilter and a modified Kalman filter as a postfilter to solve the problems of bandwidth and delay, respectively. The experimental tests are performed to evaluate the effectiveness of the proposed sensor fusion scheme. In these experiments, the accuracy in the tilt measurement is improved from 10 degrees to 0.9 degrees and 15 degrees to 0.6 degrees in low-frequency tests, and from 18 degrees to 0.8 degrees in higher frequency test. In addition, the bandwidth of the tilt measurement is enhanced from 0.16 (bandwidth of tilt sensor) to 6 Hz. The results show proper performance of the proposed approach in the line of delay compensation and increment of the bandwidth.