Energy-shaping Control Strategy Of Variable Centroid Missile Based On Port-controlled Hamiltonian Method

To achieve the maneuvering capability of the missile and improve penetration andattack performance of the warhead, moving mass motor control can be used, that is,move the mass in the missile body to change the center of mass of the missile, then usethe pneumatic trim moment to adjust the speed and attitude of the missile flight. Suchmotor control method has advantages such as simple warhead aerodynamic shape andhigh control efficiency and fast response. Since the variable centroid missile system is amultivariable nonlinear system with strong coupling between each varisble, applyingmodern control theory to search out novel advanced control methods is gettingwidespread attention. This thesis focuses on the research of novel and robust controlstrategies for the variable centroid missile system.With respect to Variable centroid Actuated Kinetic Warhead with three mass, thevariable centroid missile system can be seen as a rigid body system composed of a shellof the vehicle and internal moving mass points, By applying the Kane’s method, acomplete centroid missile dynamics equation and kinematics equation are established,and the missile nine degrees of freedom nonlinear dynamic model is derived.Applying port-controlled Hamiltonian (PCH) modeling method to construct themodel of the variable centroid missile is a brand new way. The energy stored in thesystem is taken as the energy function. The port variables of the system are chosen, andaccording to the port variables, the PCH model is designed for the system. The PCHmodel forms the foundation for studying the energy-shaping control strategy. Also, themodel has a clear physical meaning, satisfies the essence rule of the energy transmissionin the variable centroid missile system and makes the design process of the controlstrategies more clear and intuitive.In this paper, a new type of nonlinear control strategy——energy shaping controlstrategiy for variable centroid missile system is studied. The desired equilibrium pointof the system is setted according to the control objectives of variable centroid missilesystem, and the system’s desired equilibrium situation is determined, the energyequation of the system is solved, and then energy-based control law of the variablecentroid missile system is got.In this paper, the energy-shaping control strategy of the variable centroid missilesystem is simulated under Matlab/Simulink environment. The results show the missilecatch up with the target well, and the energy-shaping controll strategy is very effective,whose characteristics are suitable for the nonlinear variable centroid missile system.