Design and Implementation of Feedback Control for Counterflow Thrust Vectoring

Abstract

Aircraft thrust vector control is currently implemented using movable control surfaces such as vanes and flaps. Counterflow thrust vectoring (CFTV) is a fluidic approach to thrust vectoring that has the potential to improve on the conventional approaches by reducing weight and increasing the reaction speed. Open-loop implementation of CFTV has been demonstrated in laboratory settings. However, ultimately this technology must be implemented using feedback control. The primary control objective is to achieve fast slew rates by compensating for the transportation delay and parameter uncertainties. The paper describes an experimental test bed for investigating feedback control of CFTV. System estimation results based on open-loop test data are presented. This paper then develops a PID control law, which is sometimes implemented with a Smith predictor to compensate for the transportation delay and/or an antiwindup scheme to compensate for actuator saturation. The control laws are experimentally demonstrated, and their performance is compared using different types of reference signals.