Robust control for uncertain air-to-air missile systems

TL;DR

This paper presents a robust control approach using saturated sliding mode control, a lag compensator, and a filter to stabilize uncertain air-to-air missile systems with varying parameters and noise, ensuring quick and accurate target engagement.

Contribution

It introduces a novel robust control scheme combining sliding mode control, lag compensation, and filtering to handle multiple uncertainties in missile dynamics.

Findings

Time constant remained below 0.27s across conditions

System achieved satisfactory settling time and overshoot

Control method effectively handled high non-linearity and uncertainties

Abstract

Air-to-air missiles are used on many modern military combat aircraft for self-defence. It is imperative for the pilots using the weapons that the missiles hit their target first time. The important goals for a missile control system to achieve are minimising the time constant, overshoot, and settling time of the missile dynamics. The combination of high angles of attack, time-varying mass, thrust, and centre of gravity, actuator delay, and signal noise create a highly non-linear dynamic system with many uncertainties that is extremely challenging to control. A robust control system based on saturated sliding mode control is proposed to overcome the time-varying parameters and non-linearities. A lag compensator is designed to overcome actuator delay. A second-order filter is selected to reduce high-frequency measurement noise. When combined, the proposed solutions can make the system stable despite the existence of changing mass, centre of gravity, thrust, and sensor noise. The system was evaluated for desired pitch angles of 0{\deg} to 90{\deg}. The time constant for the system stayed below 0.27s for all conditions, with satisfactory performance for both settling time and overshoot.