Abstract: The trajectory tracking process of loitering munition is affected by wind speed and wind direction. A motion model with wind is established, and a nonlinear guidance law based on the variable gain virtual reference point and outer loop motion compensation is proposed. According to the fixed distance limit of the guidance law parameters, the variable gain virtual reference point is designed, and the stability condition of trajectory tracking is analyzed. Then the dynamic feedback compensation factor is designed for the hysteresis characteristic of the system’s outer loop, and the calculation method of the parameters and the kinematic constraints are also given. The guidance law is verified with wind and without wind through mathematical simulation. Considering the difficulty of actual flight, the tracking performance is tested on the semi physical real-time simulation platform which is built based on vc++. The results show that the improved guidance law can effectively overcome the wind disturbance, and it has high tracking accuracy but is easy to be realized.

Key words: ordnance science and technology, loitering munition, trajectory tracking, nonlinear guidance law, motion compensation, semi physical simulation