Research On Flight Control Technology For Unmanned Helicopter In Hover/Low Speed

Hover/low speed regime is very much unique to the unmanned helicopter as an operationallyuseful but most difficulties in flight control regime.It has a complex plant characteristic and easilydisturbed by the environment which brought some security problems.It is very import to do researcheson flight control strategy in hover/low speed regime and effectively solve the flight controlproblem.This paper mainly do researche on the flight control strategy based on the complex plantcharacteristic.The complex aerodynamic characteristic is caused by the interaction of the main rotor wave withthe empennage.The main rotor is rotating with high speed.Such compleity brings the lack ofaerodynamic forces and aerodynamic characteristic of the fuselage.The fuselage likely hangs underthe main rotor.It takes more control input to change the attitude of the unmanned helicopter.So,different from other unmanned aerial vehicles,it uses the attitude of the unmanned helicopter toaugment damping and stability in the hover/low speed regime.The stability augments by attitude inthe in-loop.Uses the acceleration signal to the control strategy in out-loop. Advances three methods: acontrol strategy based on common speed, a control strategy based on acceleration damping and acontrol strategy based on acceleration input on longitudinal/lateral control,and then Heave controland yaw control is easier to control than the other two control, which has designed the altitude andheading control law based on the PID feedback and feed forward compensation control.The basicflight modes of UMH during hover/low-speed flight defines by the basic flight abilities.Each modebuilds up by four basic motion.Control four basic motion can accomplish every flight ability in thehover/low speed regime.An interface is developed for the control design based on the process of the control design ofunmanned helicopter.Which used for parameters design in strategies advanced forward.Conclude thedifferent characteristic and applicable environment, provides the reference for stability augmentationand flight control strategy.At last, the control strategies advanced forward is simulated, the conclusion is that every controlstrategy can be used to the hover/low speed regime. The control strategy based on accelerationdamping is more suitable to longitudinal/lateral control.