Research On Control Technology Of Piston Engine For Unmanned Helicopter

The unmanned helicopter both have helicopters and fixed-wing UAV flight characteristics,which have a wide range of applications, development prospects and been increasingly becoming aresearch hotspot at home and abroad. The flying qualities of unmanned helicopter are directly affectedby the dynamic and static performance of engine, which as a source of motivity for unmannedhelicopter. Engine control is the precondition and foundation of the flight control, but also one of thekeys to realize autonomous flight of unmanned helicopter. In view of this, for a small unmannedhelicopter engine test bad system and its many control problems, this paper will make researches onengine modeling, engine control and control law simulation for unmanned helicopter engine controltechnology.Firstly，the average method is used to analyze the fuel and the amount of air into the cyolinder,gas model, oil model and combustion model are made separately. The force of rotor blades isanalyzed by blade element analysis method, rotor load torque model can be made. Ultimately,according to engine dynamic characteristcs, the engine speed output model can be got.Control law design is an important part of engine control, this paper will make a research onengine control from three aspects, conventional control, environmental adaptablity control andsecurity control. Engine speed achieves transition smoothly and safely to the rated speed by using thethought of segmentation control, and through the theory analysis of relation among collective pitch,forward flight speed and required power, feedforward and feedback composite control strategy isdesigned to ensure the stability of engine speed when working on rated speed. Based on the enginemodel and also the engine control technology on adaptability to environment, temperature andpressure feedback control is proposed. It can solve the problem of insufficient power supplies whenengine is used in plateau or high temperature. Additionally, fuzzy adaptive controller is also designedto achieve the environmental parameters on-line self-tuning. In addition, this paper also analyses theother possibilities that may lead to engine failure and researches the safety control technology fromthe perspective of engine control, at last, the appropriate safety control strategies are developed.Finally, the engine with the control strategy in this paper can ensure engine safety start andengine speed smooth transition by using drive test on the ground and flight test, and also the accuracyof the engine speed is controlled between1%and2%. In addition, the sample UAV flight test showsthe correctness and effectiveness of the control law and the safety control technology.