| The spinning projectiles with single channel control have the advantages of simple system and little effect of manufacturing errors,Therefore,The single channel control technology has been widely used in the fields of guided artillery,guided rocket projectile,antitank missile,anti-aircraft missile and so on.Consequently,this dissertation tries to carry out study on modelling and optimization of trajectory,analysis of flight dynamics,and guidance and control design for low-speed spinning projectiles.Firstly,in terms of the control method of low-speed spinning guided mortar,the canard coordinate system is established.The 7DOF model of the guided mortar is established by analyzing the forces and moments acting on the guided mortar,which lays the foundation for the subsequent work in this dissertation.Secondly,considering the FOV constraints of strap-down seeker in the trajectory of terminal guidance for low-speed spinning guided mortar,the model of trajectory optimization with FOV constraints is established,a modified particle swarm optimization algorithm is adopt to acquire attack angle and flight time directly.The simulation results show that the optimal trajectory can make strap-down seeker detect targets at higher heights under the constraints.Thirdly,Disturbance equations and transfer functions are conducted by the linearization of the small perturbations and "Freezing coefficient" method.And a reasonable steady-state spinning speed is designed based on the condition of dynamic stability of guided mortar.The dynamic characteristics of low-speed spinning guided mortar is analyzed to further verify the rationality of designed spinning speed.Fourthly,considering the characteristics of single channel control system,the guidance law of guided mortar is designed,the single channel control instruction is designed based on guidance law,and a contrastive study of single channel control system with open loop and closed loop is made.Considering the design requirements for actuator servo system,a dynamic model of the actuator is established to design the controller parameters of speed loop and position loop of servo motor.Finally,the single channel control system and the servo motor are applied to the simulation.The simulation results indicate that the designed guidance and control system can meet the requirements of desired design.The research of this dissertation has important reference for further engineering development. |
