Sensor Limited LQG/LTR Controller for a Subscale Aircraft Arrestment System with Nonlinear Dynamics

The goal of this paper is to present a method to design a digital controller for a motor driven aircraft subscale arrestment system of the type used on aircraft carriers. Sensors in the system are limited and there are no sensors on the aircraft being controlled. The uncertainty in the aircraft's orientation and position during arrestment along with the nonlinear dynamics and limited sensors result in control challenges. The focus of this paper is on the arrest phase controller that decelerates the plane along a reference trajectory to bring it to a final stop without steering it astray. It is based on an adaptive linear quadratic Gaussian/loop transfer recovery (LQG/LTR) control algorithm. The controller development uses a multi-input multi-output (MIMO) design technique. This is important for high performance since the system behaviors are coupled and simplifying techniques that ignore this coupling do not have the flexibility to achieve optimal performance. The algorithm developed here generates a good tracking performance for the aircraft position and velocity and successfully arrests the aircraft within bounds. The simulation and experimental results using a subscale arrestment system have shown the effectiveness of the proposed algorithm.