Study On Modeling And Control Technology Of Three-rotor Turboshaft Engine

Heavy-lift helicopter can realize high flight speed, large planeload, strong flight ability. It notonly is a good means of delivery of troops and military equipment, but also occupies a pivotalposition in the field of non-military applications. The three-rotor engines with large power, goodperformance, are more suitably equipped for the heavy-lift helicopters. But the modeling and controlresearch of three-rotor turbo-shaft engine is not found in our country. This dissertation focuses on themodeling and controllers design of the three-rotor turboshaft engine.Firstly, the components characteristics of the three-rotor turbo-shaft engine were got by themethod of characteristics modification. The static e and dynamic balance equations were built and theappropriate initial guess values were selected to solve the equations, and the three-rotor turbo-shaftengine model was built. Then the helicopter rotor model was modified and the integrated helicopter/three-rotor turbo-shaft engine model was got.Secondly, robust control of three-rotor turbo-shaft engine was studied. Augmented linearquadratic regulator (ALQR) controller was designed. The command tracking errors were augmentedthe states of the system, and the steady state error of the system was eliminated by using the stateregulation ability of LQR. The H2/H∞controller based on Linear Matrix Inequality(LMI) wasdesigned. The collective pitch was treated as disturbance during modeling. LQ index of the systemwas transformed into H2index to form a standard H2/H∞problem by constructing an output equation.Based on the interference suppression capability of the H∞, the controller disigned achieved robusttracking and disturbance rejection. The effectiveness of the two algorithms were proved by the digitalsimulation.Finally, integrated control method of three-rotor turboshaft engine was studied. The technologyof the rotor torque prediction and feed-forward control were studied to suppress the disturbance of thetorque variation of the main rotor to the power turbine rotor speed. The technology of the rotor torqueprediction based on support vector machine (SVM) algorithm was studied. A torque predictionmethod based on extreme learning machine (ELM) was proposed. A power turbine rotor speed controlmethod based on internal model principle was realized. The internal model of the input signals wasembedded into the controller and the pole placement method was used to get robust tracking. In orderto achieve effective compensation of the engine’s load variation, the Proportional-Differentialfeed-forward compensator was adopted. Digital simulation test of the integrated control system was carried out and satisfactory results were obtained.