The Design Of Terminal Guidance Law For Direct Force/aerodynamic Composite Control Missile

With modern air attack weapons increasingly being perfect,improving the ability of the intercept missile hitting the target faces serious challenges,As a result,it`s important to study the precision of missile guidance. The traditional missile based on aerodynamic control can’t meet the current demand,And aerodynamic force/direct force composite control missile can achieve high altitude, high speed, large motor, rapid interception。This thesis take the aerodynamic force/direct force composite control missile as the studying object,and chose the miss distances as the performance index of the missile to design guidance law.Firstly, the mathematic model and basic theory about the missile-target relative motion are proposed in this article, which Lay a foundation for the design of the terminal guidance law of the intercept missile. Under normal conditions, when the information of the target maneuver inserted into the guidance law is unknown,the extended state observer is used to estimate the information of the target maneuver. When the measurement noises are introduced, the extended state observer with filters is required.Secondly, designed a guided strategy based on the missile complex control system composition characteristics. Without considering the missile dynamic delay characteristics, the aerodynamic subsystem will be designed using ADRC guidance law with the magnitude of zero effort miss as a direct force turn-on threshold. When the direct force work on, the guided instruction of aerodynamic maintains direct force open time constant value, at the end of direct force, the air force system provides guided command when missile did not enter the blind area. When zero effort miss distance is not zero and missiles are into blind area, guided instruction will be got by calculating the amount of zero-effort miss. Actually missile presences dynamic delay characteristics, so it is necessary to consider the dynamic characteristics when designing delay missile guidance law. When using the same guidance policy, there must be a guided instruction dispatch problem between direct power subsystem and aerodynamic subsystem direct when direct force open. Optimal control theory will be used to solve the problem, that is, the allocation of optimal guided theory. At last, verify the guidance policy simulation according to the simulation.Finally, since the sliding mode control has strong robustness advantages, its application to the design of Missile Guidance Law has already become a trend. Select nonsingular fast terminal sliding and reaching law of power function to design the sliding mode guidance law of the aerodynamic system. When the direct force, under the optimal instructions of allocation scheme can be obtained the corresponding direct force guided instruction and aerodynamic force guided instruction. The simulation results show the effectiveness of the designed guidance law.