Robust and active trajectory tracking for an autonomous helicopter under wind gust

High levels of agility, maneuverability and the capability of operating in degraded visual environments and adverse weather conditions are the new trends of helicopter design nowadays. Helicopter flight control system should make these performance requirements achievable by improving tracking performance and disturbance rejection capability. Robustness is one of the critical issues which must be considered in the control system design for such highperformance autonomous helicopter, since any mathematical helicopter model, especially those covering large flight envelope, will unavoidably have uncertainty due to the empirical representation of aerodynamic forces and moments. The purpose of this chapter is to present the stabilization (tracking) with motion planning of a reduced-order helicopter model having 3DOF (Degrees Of Freedom) (see Fig.1). This last one represents a scale model helicopter mounted on an experimental platform. It deals with the problem of disturbance reconstruction acting on the autonomous helicopter, the disturbance consists in vertical wind gusts. The objective is to compensate these disturbances and to improve the performances of the control. Consequently, a nonlinear simple model with 3DOF of a helicopter with unknown disturbances is used. Three approaches of robust control are then compared via simulations: a robust nonlinear feedback control, an active disturbance rejection control based on a nonlinear extended state observer and a backstepping control. Design of control of autonomous flying systems has now become a very challenging area of research, as shown by a large literature (Beji & Abichou, 2005) (Frazzoli et al., 2000) (Koo & Sastry, 1998). Many previous works focus on (linear and nonlinear, robust, ...) control, including a particular attention on the analysis of the stability (Mahony & Hamel, 2004), but very few works have been made on the influence of wind gusts acting on the flying system, whereas it is a crucial problem for out-door applications, especially in urban environment: as a matter of fact, if the autonomous flying system (especially when this system is relatively slight) crosses a crossroads, it can be disturbed by wind gusts and leave its trajectory, which could be critical in a highly dense urban context. In (Martini et al., 2005) and (Martini et al., 2007a), three controllers (nonlinear,

[1]  Gabriel Abba,et al.  Robust nonlinear control and stability analysis of a 7DOF model-scale helicopter under vertical wind gust , 2008, 2008 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[2]  Gabriel Abba,et al.  CIFA 2006 Suivi robuste de trajectoires d’un hélicoptère drone sous rafale de vent , 2007 .

[3]  Stephen J. Ludwick,et al.  A loop shaping perspective for tuning controllers with adaptive feedforward cancellation , 2005 .

[4]  Semyon M. Meerkov,et al.  Disturbance rejection in control systems with saturating actuators , 2000, Proceedings of the 2000 American Control Conference. ACC (IEEE Cat. No.00CH36334).

[5]  Zhiqiang Gao,et al.  An application of nonlinear PID control to a class of truck ABS problems , 2001, Proceedings of the 40th IEEE Conference on Decision and Control (Cat. No.01CH37228).

[6]  Jing-Qing Han,et al.  Nonlinear design methods for control systems , 1999 .

[7]  Wei Wu.  Approximate output regulation of a class of nonlinear systems , 2001 .

[8]  R. Mahony,et al.  Robust trajectory tracking for a scale model autonomous helicopter , 2004 .

[9]  A. Isidori,et al.  Robust global stabilization of a class of uncertain feedforward nonlinear systems , 2000 .

[10]  Nahum Shimkin,et al.  Nonlinear Control Systems , 2008 .

[11]  L. Beji,et al.  Streamlined Rotors Mini Rotorcraft : Trajectory Generation and Tracking , 2005 .

[12]  S. Sastry,et al.  Output tracking control design of a helicopter model based on approximate linearization , 1998, Proceedings of the 37th IEEE Conference on Decision and Control (Cat. No.98CH36171).

[13]  Rogelio Lozano,et al.  Adaptive control for a radio‐controlled helicopter in a vertical flying stand , 2004 .

[14]  Rogelio Lozano,et al.  Modélisation et commande d'hélicoptères de petite taille , 1999 .

[15]  Bernard Brogliato,et al.  Nonlinear modelling and control of helicopters , 2003, Autom..

[16]  Hicham Medromi,et al.  Robust Nonlinear Control of a Miniature Autonomous Helicopter using Sliding Mode Control Structure , 2007 .

[17]  Zhiqiang Gao,et al.  A novel PID controller for pneumatic proportional valves with hysteresis , 2000, Conference Record of the 2000 IEEE Industry Applications Conference. Thirty-Fifth IAS Annual Meeting and World Conference on Industrial Applications of Electrical Energy (Cat. No.00CH37129).

[18]  Christopher I. Byrnes,et al.  Structurally stable output regulation of nonlinear systems , 1997, Autom..

[19]  H. Matsuda,et al.  Helicopter station-keeping: comparing LQR, fuzzy-logic and neural-net controllers , 1998 .

[20]  Zhiqiang Gao,et al.  Active disturbance rejection control for web tension regulation , 2001 .

[21]  Mark W. Spong,et al.  Robot dynamics and control , 1989 .

[22]  Mario Innocenti,et al.  Helicopter Flight Dynamics: The Theory and Application of Flying Qualities and Simulation Modeling , 1999 .

[23]  Zhiqiang Gao,et al.  A novel motion control design approach based on active disturbance rejection , 2001 .

[24]  E. Feron,et al.  Hierarchical control of small autonomous helicopters , 1998, Proceedings of the 37th IEEE Conference on Decision and Control (Cat. No.98CH36171).

[25]  Zhiqiang Gao,et al.  NONLINEAR DIGITAL CONTROL IMPLEMENTATION FOR A DC-TO-DC POWER CONVERTER , 2001 .

[27]  Emilio Frazzoli,et al.  Trajectory tracking control design for autonomous helicopters using a backstepping algorithm , 2000, Proceedings of the 2000 American Control Conference. ACC (IEEE Cat. No.00CH36334).

[28]  T. Hamel,et al.  Hovering flight stabilization in wind gusts for ducted fan UAV , 2004, 2004 43rd IEEE Conference on Decision and Control (CDC) (IEEE Cat. No.04CH37601).

[29]  S. Shankar Sastry,et al.  Nonlinear control design for slightly non-minimum phase systems: Application to V/STOL aircraft , 1992, Autom..

[30]  G. D. Padfield,et al.  Helicopter Flight Dynamics: The Theory and Application of Flying Qualities and Simulation Modelling , 1995 .

[31]  Ioannis Kanellakopoulos,et al.  FLEXIBLE BACKSTEPPING DESIGN FOR TRACKING AND DISTURBANCE ATTENUATION , 1998 .