Accuracy Improvement of Inertial Measurement Units via Second Order Sliding Mode Observer and Dynamic Inversion

Inertial Measurement Unit (IMU) subsystems measure accelerations or attitude rates by observing specific forces applied to a mechanical system and/or torques caused by gyroscopic effects. The IMU dynamics yield a dynamically distorted measurement and accuracy deterioration. In this paper, the IMUs accuracy is improved by reconstructing the true acceleration and the true attitude rate input signals by employing the second order sliding mode observer (2-SMO) operating in concert with dynamic inversion, given in real time distorted measurement and the IMU dynamics. The efficacy of proposed algorithms is validated on a multiple case study for a 3-stage missile interceptor with typical sampling rates of existing IMUs.