Backstepping Sliding Mode Control based Guidance Law Design with Impact Angle

For the terminal phase of AUV impact the non-stationary targets, the terminal guidance problem is studied. Based on backstepping sliding mode control method and linear extended state observer, a nonlinear guidance law with impact angle constraints is proposed. Regarding the target acceleration and external disturbance as unknown disturbance, and using the linear extended state observer to estimate the unknown disturbance. The guidance law we designed can guarantee the LOS angular rate converge to zero and impact angle converge to a desired angle before AUV hit target. Stability analysis as well as simulation results show that the presented approach is effective.