Pre-defined time convergent non-singular terminal sliding mode guidance law with impact angle constraint

Compared to single missile intercepting a maneuvering target, multi-missile cooperative attack often has a better attack effect. But at the same time, it puts forward more stringent performance indicators for guidance law, requiring multiple missiles to attack the target from different directions or at different times. In this paper, the relative motion equations of missile and target are established without using the small angle assumption, and a pre-defined time convergent non-singular terminal sliding mode guidance law with impact angle constraint is proposed, which can be applied to unpowered missile formation. That is, when the speed of missile is uncontrollable, the guidance law can make the missile hit the maneuvering target at the pre-defined impact angle, and then can be applied to the saturation attack of missile formation on maneuvering target. The numerical simulation results show that, compared with other guidance laws, the guidance law designed in this paper has higher guidance accuracy in a variety of application scenarios, and can be used to realize the cooperative attack of missile formation, which has practical significance.