Design and simulation of circular navigation guidance law with terminal impact angular constraint

In order to intercept against the fixed, uniform and maneuvering target with a certain impact angle accurately, a circular navigation guidance method based on sliding mode control is proposed in this paper. According to the geometrical analysis of the circular trajectory in a two-dimensional plane, the conclusion that only if impact angle is given, two of any points on the guidance face have a unique circular trajectory is drawn. Based on above, the mathematical model and state equation of circular guidance have been deduced. This paper adopts the sliding mode control method based on exponential approach law, making the error converge to zero in short time. The simulation results show that the circular navigation guidance can meet not only the requirement of high precision guidance but the terminal angle.