Extended Range Guided Munition Trajectory Optimum Design And Attitude Control Method Research

Extended range guided projectile trajectory characteristic and control system were studied. Improve the projectile range by rocket pushing together with glide compound extended range scheme. After making certain extended range scheme, the projectile of six DOF exterior ballistic extended range based on the projectile low speed rolling characteristic. According to the characteristics of extended range guided munition, the trajectory is divided take-off phase, rocket boost phase, free flight phase, glide phase, increasing speed phase and the ballistic model is established. The paper research fire angle of the projectile, firing time of the rocket motor, assisted time of the rocket motor, flying attitude of the glide phase and the terminal phase guidance law to add the projectile firing range. The projectile fire angle and the rocket motor firing scheme were optimized in the free trajectory phase. In the control phase, the guided projectile trajectory go on optimizing design , using firing range as target, using attack angle as dominant function, using compacting angle and compacting velocity as limits, project trajectory optimization design based on the guided projectile. The simulation results show that the projectile can attack target as larger compacting angle and compacting velocity.In order to realize the designed project trajectory that the guidance and control overall scheme is proposed and control system mathematical model of guided projectile is established. Based on these, to the characteristics of low speed rolling projectile in flying, an automatic control system is designed with the classic control methods. The air dynamic couplings were eliminated by the equivalent rudder angle method. The simulation results show that the automatic control system can make the guided projectile response perfectly and design method is simple and achieved easily.The nonlinear sliding mode theory was researched based on the nonlinear characteristic of the low speed rolling the projectile control system, making use of the invariance of the sliding mode variable structure control to parameter perturbation and external disturbance combined with differential geometry theory design control law of nonlinear system, so that both improving system robustness and solving difficult in building the nonlinear sliding surface. The system model transform as a equivalent model more easily the control design by the feedback linearization, so that this paper transform system model base on feedback linearization theory in the nonlinear system design. The differential geometry theory combined with sliding variable structure control theory, based on feedback linearization variable structure control method was given, proving the designed controller is stable, then the design method was used to controller design of low speed rolling guided projectile and get better results. The complex nonlinear guided projectile control system problem was converted into several single input single output subsystem with this method and solving strongly nonlinear of the guided projectile dynamic characteristics. The simulation results show that the controller perfect robustness to the parameter changes of a control system and external interference and the designed control system dynamic characteristics is good. The comparison show that the paper controller designed is better than the PID controller.