Accuracy improvement of a multi-MEMS inertial measurement unit by using an iterative UFIR filter

In this paper a two layers multi-sensor fusion method is presented to combine output of four low cost, low accuracy MEMS inertial measurement units (IMU) to be used in an inertial navigation system (INS). A Minimum Mean-Square-Error (MMSE) criterion measurement fuser in the first and an iterative unbiased finite impulse response filter in the second layer are utilized to reduce measurement noise effect. The static experimental results verify that angle random walk (ARW) error for x,y and z axes of combined gyroscope reduces up to 2.37 times. Moreover dynamic experimental results show that by choosing optimal horizon interval, the standard deviation of the multi-IMU decreases by a factor of 5 respect to the mean standard deviation of the four sensors that leads to accuracy improvement compared to the single sensor.