Research On Longitudinal Control Technology In Forward Flight Of Unmanned Helicopter

In order to further improve the vertical control technology of unmanned helicopter at forward flight,the dissertation studied the coordinated control of height/speed,the safety control of engine power protection and the secondary development of helicopter model RotorLib respectively.First in order to achieve the coordinated control of height and speed.this dissertation first from the coupling of maneuverability and state coupling demonstrated the coupling of height and speed,and then,based on the longitudinal cycle pitch compensation and collective pitch compensation,respectively,to achieve the height and speed of the coordinated control,the results show that the height/speed coordinated control based on collective pitch compensation achieves better results than the height/speed coordinated control based on longitudinal cycle pitch compensation.Finally,the dissertation uses wind disturbance and center of gravity/the quality uncertainty verifies the robustness of height/velocity coordinated control based on collective pitch compensation.Secondly,in order to ensure flight safety,improve unmanned helicopter operating capability,the dissertation research on the protection of engine power.In this dissertation,the influence of altitude and temperature on engine power is analyzed firstly,the engine power demand under different flight states is calculated,and then the situation of engine power shortage is simulated and analyzed.Finally,open-loop control of the engine speed is used to trigger the self-adjusting lifting speed,Open-loop control of collective pitch and lifting speed adjustment,closed-loop control of lift speed feedback form engine speed to achieve the safety control of engine power protection.The results show that the closed-loop control with the speed of lift feedback engine speed is the best.Lastly,In order to further improve the RotorLib modeling method,the dissertation realizes the four kinds of uncertainty functions of mass,center of gravity,moment of inertia and force through the secondary development and packaging.At the same time,in order to save money on purchasing the M language version and a unified lab development environment,the author uses CMEX technology,small disturbance principle to achieve the trim and linearization Development under MATLAB.