Uncertainty Modeling and Robust Minimax LQR Control of Hypersonic Flight Vehicles

Longitudinal flexible body models of canard configured air-breathing hypersonic flight vehicles (AHFV) with intricate couplings and interactions are difficult to feedback linearize. The presence of input terms in the low order derivatives of the outputs and uncertainty in the system makes the feedback linearization a highly challenging task. In this paper, we approach this problem in a robust way such that all the uncertainties are lumped together and can be written in a way that is useful for controller synthesis. Using this approach, we derive a control-oriented linearized uncertainty model (CLUM) for an AHFV. In this study, twenty four inertial and aerodynamic parameters are considered to be uncertain. Furthermore, using the derived CLUM, a robust minimax LQR controller is synthesized to track velocity and altitude step input commands. Simulation results using a curve fitted model (CFM) and varying uncertain parameters are presented to demonstrate the effectiveness of the CLUM and minimax control design method.

[1]  Robert F. Stengel,et al.  Robust Nonlinear Control of a Hypersonic Aircraft , 1999 .

[2]  I. Petersen,et al.  Minimax optimal control of uncertain systems with structured uncertainty , 1995 .

[3]  Andrea Serrani,et al.  Nonlinear control of non-minimum phase hypersonic vehicle models , 2009, 2009 American Control Conference.

[4]  Andrea Serrani,et al.  Development of Linear Parameter-Varying Models of Hypersonic Air-Breathing Vehicles , 2009 .

[5]  David B. Doman,et al.  Control-Oriented Modeling of an Air-Breathing Hypersonic Vehicle , 2007 .

[6]  Ian R. Petersen,et al.  Robust nonlinear control of a nonlinear uncertain system with input coupling and its application to hypersonic flight vehicles , 2010, 2010 IEEE International Conference on Control Applications.

[7]  I. Petersen,et al.  Robust Control Design Using H-? Methods , 2012 .

[8]  A. Serrani,et al.  Nonlinear Robust Adaptive Control of Flexible Air-Breathing Hypersonic Vehicles , 2009 .

[9]  A. Isidori.  Nonlinear Control Systems , 1985 .

[10]  D.B. Doman,et al.  Robust nonlinear sequential loop closure control design for an air-breathing hypersonic vehicle model , 2008, 2008 American Control Conference.

[11]  Obaid Ur Rehman,et al.  Minimax LQR Control Design for a Hypersonic Flight Vehicle , 2009 .

[12]  Ian R. Petersen,et al.  Uncertainty Modeling for Robust Multivariable Control Synthesis of Hypersonic Flight Vehicles , 2009 .

[13]  Ian R. Petersen,et al.  Robust Control Design Using H-infinity Methods , 2000 .

[14]  Michael A. Bolender,et al.  Flight Path Angle Dynamics of Air-breathing Hypersonic Vehicles , 2006 .

[15]  Petros A. Ioannou,et al.  Adaptive Sliding Mode Control Design fo ra Hypersonic Flight Vehicle , 2004 .

[16]  Ian R. Petersen,et al.  Robust minimax optimal control of nonlinear uncertain systems using feedback linearization with application to hypersonic flight vehicles , 2009, Proceedings of the 48h IEEE Conference on Decision and Control (CDC) held jointly with 2009 28th Chinese Control Conference.