Cascaded LQR Control for Missile Roll Autopilot

Optimal control as a modern control system design approach when used in aerospace applications can meet the requirements of fast response with minimum settling time and good stability characteristics. Linear Quadratic Regulator is a ubiquitous controller which can be used effectively in the design of a missile roll autopilot. Roll autopilot in an aerodynamically controlled missile aims to keep roll angle and rate zero so that the roll and lateral dynamics of the missile are decoupled resulting in stable performance characteristics. This paper discusses a cascaded LQR controller for effective roll stabilization of the missile autopilot in a realistic model where the second order actuator and gyro dynamics are also considered. Simulations are carried out to demonstrate the effectiveness of the controller.