This paper proposes a guidance law for missiles with control time constraint. Because the proposed guidance law is based on a time-to-go polynomial, it has a generalized form. Also, acceleration of the proposed law converges to zero at the end of the control time, which reduces the sensitivity to the time-to-go estimation error and can increase the flight stability when the separation of the missile appears. A prediction method of the time-to-go is proposed for implementing the proposed law, and the possibility of application to the midcourse and terminal guidance phases is dealt with for exoatmospheric interception. The characteristics and performance of the proposed law are analyzed throughout various simulations.

This paper presents a composite guidance law with fiber-optic line (FOL) and look angle constraints for air-to-ground anti-tank missiles. The long-range anti-tank missiles launched from helicopters are typically equipped with a wired datalink system based on a fiber-optic line, which is used to acquire target information and enable the seeker’s lock-on, and a seeker for the terminal homing guidance. Therefore, in the design of the guidance law, both the constraints of the FOL and the seeker’s look angle should be considered to ensure mission success. The proposed law consists of three guidance phases: the first guidance is to control the flight-path angle for avoiding interference between the FOL and the launch platform; the second is to maintain a constant look angle so that the target remains within the seeker’s field-of-view (FOV); the final is to attack the targets with the desired impact angle. Nonlinear simulation results confirm that the proposed law satisfies both the FOL and look angle constraints while achieving the desired terminal impact angle.