Reconfigurable Nonlinear Autopilot

The paper proposes a reconfigurable flight-control system for the tracking of altitude, heading, sideslip, and velocity commands. The control law can serve for the command of unmanned air vehicles or as an autopilot for piloted aircraft. The inner core of the algorithm consists of a reconfigurable control system providing tracking of pitch-, roll-, and yaw-rate commands. It is based on a model reference control law and a stabilized recursive least-squares algorithm. The outer loop is based on a linear design, with compensation for the nonlinear couplings arising from flight dynamics. Some parameters of the outer loop are identified in real time in order to adapt to varying flight conditions. The algorithm is evaluated using a nonlinear F-16 simulation model. The results demonstrate the consistent performance of the algorithm through various flight conditions, as well as its turn coordination capabilities, its reconfiguration after a floating left elevator failure, its ability to move across the power curve, and its tolerance to measurement noise and turbulence.

[1]  Ronald A. Hess,et al.  Multi-Input/Multi-Output Reconfigurable Flight Control Design , 2001 .

[2]  Phillip R. Chandler,et al.  UAV cooperative control , 2001, Proceedings of the 2001 American Control Conference. (Cat. No.01CH37148).

[3]  Raman K. Mehra,et al.  A Hybrid Fault-Tolerant Scheme for Flight Control Applications* , 2001 .

[4]  R. Beard,et al.  TRAJECTORY PLANNING FOR COORDINATED RENDEZVOUS OF UNMANNED AIR VEHICLES , 2000 .

[5]  Karl Johan Åström,et al.  Adaptive Control (2 ed.) , 1995 .

[6]  Marcello R. Napolitano,et al.  On-Line Learning Nonlinear Direct Neurocontrollers for Restructurable Control Systems , 1995 .

[7]  M. Bodson.  An adaptive algorithm with information-dependent data forgetting , 1995, Proceedings of 1995 American Control Conference - ACC'95.

[8]  David B. Doman,et al.  DEVELOPMENT OF A HYBRID DIRECT-INDIRECT ADAPTIVE CONTROL SYSTEM FOR THE X-33 , 2000 .

[9]  Marc L. Steinberg,et al.  Comparison of Intelligent, Adaptive, and Nonlinear Flight Control Laws , 1999 .

[10]  Marc Bodson,et al.  COMMAND LIMITING IN RECONFIGURABLE FLIGHT CONTROL , 1998 .

[11]  Kevin A. Wise,et al.  Flight Testing of Reconfigurable Control Law on the X-36 Tailless Aircraft , 2001 .

[12]  Uy-Loi Ly,et al.  Design of a total energy control autopilot using constrained parameter optimization , 1991 .

[13]  David G. Ward,et al.  Development and Flight Testing of a Parameter Identification Algorithm for Reconfigurable Control , 1998 .

[14]  Frank L. Lewis,et al.  Aircraft Control and Simulation , 1992 .

[15]  Ping Lu,et al.  Two Reconfigurable Flight-Control Design Methods: Robust Servomechanism and Control Allocation , 2001 .

[16]  Nicolas Schindler,et al.  Phugoid dynamics control , 2001 .

[17]  Wright-Patterson Afb,et al.  Integration of On-line System Identification and Optimization-based Control Allocation* , 1998 .

[18]  John H. Blakelock,et al.  Automatic control of aircraft and missiles , 1965 .

[19]  R. Bodson,et al.  Multivariable adaptive algorithms for reconfigurable flight control , 1994, Proceedings of 1994 33rd IEEE Conference on Decision and Control.

[20]  Stefan Preitl,et al.  An extension of tuning relations after symmetrical optimum method for PI and PID controllers , 1999, Autom..

[21]  Donald McLean,et al.  Automatic Flight Control Systems , 1990 .

[22]  David G. Ward,et al.  Indirect adaptive flight control of a tailless fighter aircraft , 1999 .

[23]  Petros G. Voulgaris,et al.  Parameter identification for systems with redundant actuators , 1998 .

[24]  Anthony J. Calise,et al.  Development of a Reconfigurable Flight Control Law for Tailless Aircraft , 2001 .