Output Feedback Control and Sensor Placement for a Hypersonic Vehicle Model (Preprint)

This paper addresses issues related to output feedback control, including sensor placement, for a model of an air-breathing hypersonic vehicle. The model presents a number of control challenges, in particular because of strong couplings between the propulsive and aerodynamic forces. Because of the vehicle's low weight, slenderness, and length, the vehicle's flexibility has a large impact on stability and control of the vehicle. Two output feedback control methods are developed. One applies reconstruction of the flexible body system states, toward applications of state feedback control. The other uses a robust design that does not rely on an observer to ensure stabilization and performance throughout a given flight envelope. A rate gyroscope and an accelerometer have been modeled, incorporating the flexible effects, and strategies for sensor placement have been developed for the hypersonic vehicle model to enhance observability or to preserve certain system structures that are favorable for robust control design. Simulation results are provided to demonstrate the sensor placement strategies and output feedback control performances. Presented at the AIAA Conference and Exhibit (2007) on Guidance, Navigation and Control held at Hilton Head, SC on 20-23 Aug 2007.