Research On Mechanism And Elimination Of Surplus Torque In Electric Torque Load Simulator

Electric load simulator(ELS) is a hardware-in-loop equipment which is used to simulate the aerodynamic hinge moment suffered by high speed aircraft. It is an important performance testing facility in laboratory and to some extent, determines the flight precision of aircrafts like missiles. Surplus torque is the main factor that contributes to the torque servo error of ELS, and the deep research concerning mechanism and elimination method of surplus torque has great significance in engineering. Taking simulation technology of high-speed aircraft servo load as background and based on transfer function and state-space model separately, this paper makes detailed analysis on mechanism of surplus torque and construct its mechanism model. According to the in-depth analysis on dynamic characteristic, elimination methods of surplus torque is designed and a complete control structure and design process of controllers is given in this thesis. Finally, correctness and feasibility of control theories raised in this thesis are verified by simulation results and experiments on physical facility.Firstly, research background and significance of ELS system is stated. Research status of ELS, achievements and deficiencies of surplus torque elimination are summarized in this paper.Secondly, based on the mathematical models of torque loading system and rudder, integrated transfer function model and state-space model are built. By the analysis of surplus torque mechanism, transfer function model of surplus torque is constructed; meanwhile, expression of surplus torque based on ELS state-space model is given. Finally, similarities and differences of these two models are analyzed.Thirdly, elimination methods of surplus torque are designed based respectively on analysis of two surplus torque expressions raised before. To surplus torque’s transfer function model, system parameters and input signals, which will probably influence characteristics of surplus torque, are analyzed in detail. After locate several influential parameters, specific feedforward control strategies are designed. To surplus torque’s state-space expression, decoupling control algorithm is designed for error elimination. Moreover, transformation matrix for decoupling canonical form is given and proved for its correctness.Finally, based on control algorithms stated before and nominal parameters of a specific ELS equipment, integrated design and simulation experiment of control algorithm are fulfilled. Control algorithms are also carried out on this ELS equipment. Simulation and experiment results all verified the feasibility of the control methods raised in this thesis.