Design Of Terminal Guidance Law And Integrated Research For Homing Missiles

The guidance system and control system are the important parts of the missile.They are the keys to realize the accurate strike of the missile.With the improvement of the movement performance of the targets,the traditional guidance and control laws can no longer meet the guidance performance.So it is necessary to consider the new guidance and control methods to improve the overall performance of the missile.In this paper,striking maneuver target in the final terminal guidance is taken as the research object.The guidance law for the target of high-speed maneuvering in the atmosphere and the way of integrated guidance and control are studied based on the theory of sliding mode variable structure and the idea of adaptive inversion design.The research contents are summarized as follows:Firstly,the relative motion model and the integration equations of guidance and control are established.The model of missile control system are derived based on the equations of missile space motion.The model of the control system and the guidance model are combined to establish the three-channel independent integration model.Secondly,based on the guidance model that is derived,the second-order dynamics of missile autopilot are added to the guidance model and the new model accounting for the second-order dynamics of autopilot is studied.Considering the time of terminal guidance is limited,a sliding mode guidance law with finite time convergence accounting for the second-order dynamics of autopilot is designed according to the sliding mode control theory.In order to weaken the chattering caused by sliding mode control,the hyperbolic tangent function is used to improve the guidance law.The advantages of the designed guidance law are proved by comparing it with the classical proportional guidance law.Thirdly,based on the derivation of three-channel independent integration model,sliding mode variable structure theory and adaptive inverse design idea,the integration algorithms of the missile three channels are designed.In order to weaken the chattering caused by sliding mode control,the hyperbolic tangent function is used to improve the integration algorithms.The simulations show that integration algorithms have good robustness and stability.When they are compared with the traditional independent design methods,it also shows their advantages.Finally,The integration problem with attack angle constraint is studied in the obtained integration model.The constraint with attack angle of three-channel independent integration model is established by converting the attack angle constraint to the line of sight angle constraint.The integration with attack angle constraint is presented with the idea of previous integration research.Numerical simulation shows the validity and feasibility of the integrated algorithm.