New method for posture estimating of non-gyro inertial measurement unit

Non-gyro inertial measurement unit (NGIMU) uses only accelerometers replacing gyroscopes to compute the motion of a moving body. A new compensation method for posture estimating of NGIMU is proposed on the actual condition of existing the accelerometer mounting error, which seriously affects the precision of the navigation parameter estimation. The algorithm uses the error function of the accelerometer output, and compensates the posture parameter in the traditional posture estimating algorithm to reduce the accelerometer mounting error. Using the traditional accelerometer configurations for reference, a novel nine-accelerometer configuration of NGIMU is also presented with its mathematic model constructed. The simulations of the proposed algorithm are investigated based on the presented NGIMU configuration. The simulation results show that the new algorithm can effectively improve the precision of the angle estimating.