Design and Flight Testing of an Adaptive Gain-Scheduled Controller Using On-Line Model Estimation

Abstract

An adaptive gain-scheduled flight control law is designed for a transport aircraft to cope with sensor/actuator faulty conditions or any airframe change. This work takes place as part of the H2020 European/Japanese project VISION (Validation of Integrated Safety-enhanced Intelligent flight cONtrol). Practically, a gain-scheduled controller is designed off-line at first, by using a state-space modal technique to synthesize a control law which affinely depends on the major model aerodynamic parameters instead of the usual measured flight parameters (airspeed, altitude,…). Besides, an estimation algorithm is developed to track these time-varying parameters on-line, and to update the values of the main stability/control derivatives used to schedule the controller (i.e. the coefficients involved in the development of the aerodynamic forces). A primary concern being on-line implementation, the adaptive process is developed so as to minimize the on-board computational burden and the algorithm complexity. Preliminary results achieved during Hardware-In-the-Loop Simulations and flight tests using the MuPAL-alpha research aircraft of JAXA illustrate the implementation and a first evaluation of this adaptive scheme.