Attitude Control Law Design Based On Blended Lateral Jets And Aerodynamic Control

This thesis is focused on attitude control of missiles with canard configuration and side jets. To deal with the nonlinearity, coupling of the missile dynamics, the design of blended aerodynamic and side-jet control law based on dynamic inversion method is investigated. Thennonlinear disturbance observer is used to estimate and compensate system disturbances and uncertainties. The main researches are as follows.First, the model of blended aerodynamic and set-jet control missile is constructed. Based on the configuration of missile, the aerodynamic forces and moments, the side jet forces and moments are analyzed to construct the dynamic equations. A nonlinear model of the system is constructed and simplified.Second, the blended control laws based on dynamic inversion method are designed. A control law based on dynamic inversion and time-scales separation is designed for aerodynamic rudders. Based on the analysis of side jets disturbance on the aerodynamic control system, the decoupling blended control law is designed with fast respense. The blended control law contains a moment control law based on the dynamic inversion, and a simple moments allocation method to assign moments to side jet thrusters and rudders.Third, perturbations of system are compensated based on nonlinear disturbance observer. The structure of disturbance observer is analyzed and a specific observer is designed for the system. The results of observation are used to compensate the system perturbantions.Last, the system simulation model is constructed and the performaces of decoupling control law and blended control law are verified by numerical simulations. The simulation results show that the compensation method is effective to stabilize the perturbed system.