Design Of Guidance And Control System For Hypersonic Flight Vehicle

Hypersonic flight vehicle is widely studied in military field due to its prominent speed advantage.The technology of guidance and control is one of the key technologies of hypersonic flight vehicle.Whether the vehicle can hit the target precisely is determined by the performance of guidance and control system.In order to exert greatest damage effect,except for the requirement of miss distance we also expect that the vehicle can hit the target with desired incidence angle.This paper was based on the background of one non-powered hypersonic flight vehicle attacking fixed target and the guidance and control system with terminal impact angle was designed.The main work of this paper is shown as follows:1.By analyzing the aerodynamic and kinematic characteristics of hypersonic flight vehicle,the six degree-of-freedom mathematical model and aerodynamic model were established.Since the six degree-of-freedom model was in quite complex form and the coupling between channels was serious,it's difficult to design the guidance and control system directly.Based on reasonable assumption and simplification,this paper established the mathematic model in pitch plane of hypersonic flight vehicle and laid foundations for the following design of guidance and control system.2.Guidance and control system was composed of guidance loop and control loop.This paper designed the guidance law and controller separately on this basis.The design of guidance law required that the vehicle should meet both the miss distance constraint and impact angle constraint.By analyzing the kinematic relationship between hypersonic flight vehicle and target,this paper established the guidance model with terminal impact angle.Based on the guidance model,a proportional guidance law and a sliding mode guidance law with terminal impact angle were designed.The contrast simulation results proved the rationality of the designed guidance laws.3.This paper established the control-oriented model on the basis of mathematical model in pitch plane.Aiming at the problem of nonlinearity,random uncertainty and performance of real-time,sliding mode control was adopted to design controller for hypersonic flight vehicle.First,a kind of traditional sliding mode controller was designed.In order to improve the response quickness,control precision and robustness,terminal sliding mode control and adaptive control were adopted to design controller.The chattering of sliding mode control was weakened by terminal sliding mode approaching law.By comparing the simulation results of two controllers,the adaptive terminal sliding mode controller was proved to be more effective.4.By combining the proportional guidance law and the adaptive terminal sliding mode controller,the guidance and control system of hypersonic flight vehicle was obtained.The rationality system was proved by combined simulation.Hypersonic flightvehicle could hit the target with terminal impact angle precisely under the action of guidance and control system.