Trajectory Optimization And Tracking Control Of Combined Power Aerospace Vehicle In Climbing Phase

Compared with the traditional rocket launch window,the combined power aerospace vehicle which can take off and land horizontally has larger launch window and lower launch cost due to its reusable characteristics,so it has the ability of emergency orbit entry in wartime;At the same time,the combined power aerospace vehicle can also be used as a hypersonic aircraft,which can be used for fast approaching reconnaissance in high threat areas,and can carry weapons to carry out fast strike missions.In recent years,more and more attention has been paid to the combined power aerospace vehicles.Climbing phase is the key to the success of the follow-up mission of the combined power aerospace vehicle.Trajectory design and optimization is the basis of the follow-up tracking control.At the same time,due to the strong nonlinearity and strong coupling of the combined power aerospace vehicle,and its actuator may be limited in the flight process,how to ensure its accurate tracking of guidance instructions is also very important.Therefore,this paper takes the combined power aerospace vehicle as the research object,considering its strong nonlinearity and actuator constraints,and focuses on the trajectory optimization and tracking control of its climbing phase.According to the different power forms,the climbing section of combined power aerospace vehicle can be divided into three parts: vortex jet climbing,vortex jet ram transition climbing and ram climbing.Firstly,the appropriate coordinate system is defined,and the transformation relationship between coordinate systems is determined.Then,the configuration of combined power aerospace vehicle is designed with reference to the same type of aircraft at home and abroad,and some parameters are given.On this basis,based on N ewton’s law of motion and the theorem of moment of momentum,the complete equations of motion of the system are established,and the thrust and aerodynamic force / torque models of the combined power aerospace vehicle in the climbing phase are established.Then the flight profile of the combined power aerospace vehicle in the climbing phase is analyzed.Then,based on H P adaptive Gauss pseudospectral method and sequential quadratic programming algorithm,the flight trajectory of the combined power aerospace vehicle in the climbing phase is optimized.The basic principles of HP adaptive Gauss pseudospectral method and sequential quadratic programming algorithm are introduced.Considering various process constraints and terminal constraints,the optimal performance index is given.Based on this,the optimal trajectory of climb phase is designed,and then the flight corridor of climb phase is obtained.The simulation results show that the optimal trajectory obtained by Gauss pseudospectral trajectory optimization can be used in the climbing phase of combined power aerospace vehicle,and can meet the requirements of subsequent tasks.Considering that the trajectory of the climbing phase is relatively violent in the longitudinal plane,the climbing phase motion model of the combined power aerospace vehicle is simplified longitudinally,and the active disturbance rejection angle of attack tracking controller is designed based on the simplified model.Due to the large number of ADRC parameters and the complexity of parameter tuning,particle swarm optimization algorithm is introduced to optimize the parameters of the angle of attack tracking controller.Then the design and Simulation of the angle of attack tracking controller under the constraint of the aircraft actuator are carried out.Finally,the optimal angle of attack curve obtained by trajectory optimization is tracked based on the designed controller.Simulation results show that after particle swarm optimization,the tracking effect of active disturbance rejection(ADRC)angle of attack tracking controller for angle of attack is significant,and the tracking effect of the designed controller does not change much when the actuator of the aircraft is limited,which achieves the initial goal of the controller design.