Design of a supervisory controller for CLOS guidance with lead angle

Abstract

Purpose -The purpose of this paper is to propose a supervisory command-to-line-of-sight guidance law with lead angle which keeps the missile flight within the tracking beam. Design/methodology/approach -A nonlinear supervisory controller is designed and coupled with the main sliding mode controller in the form of an additional control signal. The supervisory control signal is activated when the beam angle constraint goes to be violated. Initially a supervisory controller is designed using nonlinear control theory. Subsequently the main tracking controller is designed using sliding mode approach which forces the missile to fly along the desired line-of-sight. The stability of the supervisory controller coupled with the main controller is proved in the Lyapunov sense.Findings -There exists a major drawback with the lead angle method of guidance, which is a high probability of flying out of the beam. The proposed supervisory controller has successfully overcome this deficiency. Thus, a better performance has been achieved. Practical implications -The proposed guidance scheme can be applied to tactical surface to air missiles. Additionally the idea of supervisory controller can be applied to any similar control problem where there are some constrains over the states of the system. Originality/value -The idea of supervisory controller has not been applied to the problem of command-to-line-of-sight guidance law. This paper utilizes and extends the idea of supervisory controller design to cases when a special state is to be supervised while considering the effect of external disturbances.

Integrated CLOS and PN Guidance for Increased Effectiveness of Surface to Air Missiles

“…In command to line-of-sight guidance, normal and lateral acceleration commands are relayed to the in-flight missile to make the displacement of the missile from the direct line-of-sight to the target as small as possible, in elevation (pitch) and azimuth (yaw) planes. For low speed targets, the performance of CLOS is known to be good [6]. But upon increasing the target velocity, the demanded acceleration increases as a result of increasing the curvature of missile trajectory.…”

“…High probability of the missile flying out of the beam is a major shortcoming of lead angle method. A supervisory CLOS guidance law with lead angle [6] was proposed to address this limitation of lead angle method and keep the missile flight within the tracking beam. Later, a new optimal-fuzzy two-phase CLOS guidance law INCAS BULLETIN, Volume 9, Issue 2/ 2017 [10] was proposed to reduce the acceleration demands in the midcourse phase of missile flight and coupling of supervisory and main tracking controller was introduced to ensure missile flight within the beam.…”

“…The principle of command to line-of-sight (CLOS) guidance [3][4][5][6] is to make the missile fly as near as possible along the instantaneous line joining the tracker and the target, called the line-of-sight. The target and the missile are tracked by the ground tracking system in CLOS guidance.…”