Design Of Guidance And Control System For Extended Range Guided Projectile

Over the past 30 years,the army has used guided projectiles for fixed point clearance to achieve good combat effectiveness in several local wars.Guided projectiles have a lower cost than missiles and have a higher precision compared with conventional shells.With the development of the warfare mode that the army must have the ability to strike accurately at a large distance,how to improve the range of guided projectiles become an important research field.In this paper,based on the domestic demand for extended range guided projectile,the scheme that adopt BTT(Bank-to-Turn,reffered to as BTT)control and has high lift-drag ratio shape was studied in order to improve the range.First,the development of foreign guided projectiles is described in this paper,then according to the requirement of some guided projectiles need long-range,several schemes were compared,a method that adopting high lift-drag ratio shape to glide is proposed.To ensure the maneuverability of the projectile,the means that the projectile is controlled by BTT in final guidance segment was proposed.Then this paper introduces the theoretical research status of BTT control technology and guidance technology at home and abroad.According to the aerodynamic shape of the long-range projectile,the mathematical model describing the motion of the projectile and the state space model of the projectile and the projectile transfer function used to analysis the control system are set up.The design of two loop autopilot,two loop autopilot with PI and three-loop autopilot were done by using pole assignment method and LQR,then to simulate.Based on the requirement of BTT control,using the analytic method to design roll autopilot.The importance of the yaw channel autopilot in a coordinated turn has been analyzed in this paper.When adopting BTT control,there will be coupling between channels,In order to reduce coupling between channels,the relationship of the response speed of the three channel autopilot is discussed.By the simulation,the relationship between the three channels is determined.According to this,the design of the three channels autopilots of adopting BTT to control were carried out based on the classical single input and single output then Introducing coupling and drifting off paraments to carry out simulation.Based on the high lift-drag ratio shape,the trajectory has been designed.The trajectory was divided into glided segment and the final guidance segment to study.In glided segment,the strategy of maximum lift-drag ratio slide was verified by simulations.In final guidance segment,a study of the biased proportional guidance which can control terminal angle is carried out.Using this method,projectile can attact the target at big impact angle.Then analying the lateral modification,when the projectile was controlled by BTT.In the end,the whole trajectory simulation was carried out.