Investigation of cumulative retrospective cost adaptive control for missile application

A cumulative retrospective cost adaptive control algorithm is augmented to a gain-scheduled three loop autopilot to assess performance in a nonlinear three-degree-of-freedom missile model. The cumulative retrospective cost adaptive controller requires minimal model information; specifically estimates of the relative degree, 1st nonzero Markov parameter, and nonminimum phase zeros of the linearized missile model. A rate gyro sensor failure is applied to the model and the performance of the control techniques is investigated through an analysis of air-to-air intercept scenarios. The results indicate that an adaptive controller can, to some degree, improve the missile’s ability to engage a target when such a failure occurs. Nomenclature m Missile mass Iyy Missile Inertia g Acceleration due to gravity X;Z Inertial position in the X-Z plane U Inertial velocity component along the body frame x-axis of the center of gravity (CG) W Inertial velocity component along the body frame z-axis of the CG Vm Magnitude of missile velocity M Mach number Az;P Acceleration component along body frame z-axis at pointP along the body x-axis Angle of attack Pitch angle q Body rate Air density Sref Reference area dref Reference length Cx Aerodynamic force coefficient along the body frame x-axis Cz Aerodynamic force coefficient along the body frame z-axis Cm Aerodynamic moment coefficient along the body y-axis at the CG q Dynamic pressure p Tail fin angle T Thrust along body frame x-axis