Angular velocity estimation in gyroscope-free inertial measurement system based on unscented kalman filter

A gyroscope-free inertial measurement system(GFIMS) uses only accelerometers to measure angular velocity and specific force. It is a low-cost inertial measurement system. But the value of angular velocity is computed by the outputs of accelerometers, its accuracy is lower than that of a conventional inertial measurement system equipped with gyroscopes. So it is very necessary to research on high accuracy and real time estimation algorithm of angular velocity in gyroscope-free IMS. Unscented kalman filter(UKF) is a novel filter method for the nonlinear gauss system, which can obtain higher accuracy than the conventional. In this paper, the UKF is used to estimate values of angular velocity in gyroscope-free IMS based on analysis of nonlinear gyroscope inertial measurement model. And the extended kalman filter(EKF) is compared with the UKF through a example simulation. Simulation results show that the UKF is superior to the EKF method to estimate the angular velocity in gyroscope-free IMS.