Design Method Of Guidance Law And Autopilot For Gliding Aircraft

As an air-to-ground weapon, Gliding aircraft has some advantages, such as largerlift-drag ratio and longer flight distance. But its attack characteristics and structuralfeatures have brought some challenges to its guidance loop and control loop design aswell. Here unpowered glider flight vehicle is chosen as the research object. Theguidance law with terminal Angle constraint is designed and the bank-to-turn (BTT)gliding aircraft autopilot is designed in this paper. This paper research mainly includesthe following aspects:First of all, aiming at the glide of aircraft structure studied in this paper, itsdynamic model and kinematics model is established; equation of relative motionrelations is established respectively in the pitch plane and swerve plane when glidingaircraft hit the ground fixed target, laid the foundation for subsequent research work.Second, when gliding aircraft hits the ground fixed target, design problem ofguidance law is converted into the reference trajectory tracking problem. First thing isplanning reference trajectory by applying the classical optimal control theory, and nextis designing the fuzzy controller and the nonlinear generalized predictive control(NGPC) controller to control the gliding vehicle tracking reference trajectory. The twomethods can both realize the tracking reference trajectory. Simulation results show thatthe precision of fuzzy controller is high, but the requirement for gliding flight vehiclenormal acceleration is also high. But the precision of NGPC controller of fuzzycontroller is a bit poor, at the same time, the requirement of the normal acceleration issmooth, and it’s easy to realize in engineering.Finally, design of the bank-to-turn (BTT) gliding aircraft autopilot is finished.Based on the situation that overload instruction given by guidance system is changedinto Angle of attack, sideslip Angle and roll Angle of instruction, directly aiming atglide nonlinear model of aircraft, the autopilot design is transformed into internal andexternal circuit design, application of NGPC algorithm design of internal and externalloop controller, the instructions to the rudder Angle is gotten according to the Angle ofattack, sideslip Angle and roll Angle. Simulation shows that this design of thebank-to-turn (BTT) gliding aircraft autopilot meets the engineering requirements.