Research On Disturbance Torque Suppression And Dynamic Loading Precision Of Electric Torque Loading System

The electric torque loading simulator(ETLS)is used to simulate the aerodynamic torque load on aircraft rudder systems during normal operation or attitude adjustment in flight,and test the performance of rudder system by analyzing experimental data.As the loading performance of ETLS plays an important part in the result of rudder system experiment,it is significant and worthy to study the torque loading technology of ETLS.This paper focuses on the research of disturbance torque suppression and dynamic loading precision improvement method for ETLS.Based on the researches status analysis of the electric and electro-hydraulic torque loading simulator,this paper determined the ETLS as the object to research the small and high-precision torque loading technology.Then,technical approach to improve the performance of ETLS is analyzed in this paper,and main factors affecting the performance of ETLS,including surplus torque and friction nonlinear factor are analyzed.Furthermore,control methods of surplus torque and friction nonlinear factor are summarized from the perspective of compensation control.And the research status on measures of improving systems bandwidth is also elaborated.All of these studies lay a technical foundation for the research of disturbance torque suppression and dynamic loading precision improvement method of ETLS in this paper.In order to research the disturbance torque suppression and dynamic loading precision improvement method of ETLS,an ETLS is developed in this paper.A loading system which selects a DC torque motor as execution unit is developed based on high-precision and strong anti-interference guidelines in the first place,and a steering system which selects an AC servo motor and a planetary gear as mechanical body is also developed in order to simulate the movement of real rudder system to test the performance of loading system.Considering the interaction of the torque and angular position output of ETLS,the linear mathematic model of ETLS is established based on mechanisms analysis method,which takes the steering system characteristics into account.Furthermore,in order to study the effect of friction nonlinear factor on torque output of ETLS,a dead-zone link is introduced to describe the friction nonlinearity,which is added to the linear mathematic model to build the integratedmathematic model of ETLS.The closed-loop control performance and disturbance torque suppression method of ETLS is deeply studied in this paper.In order to solve the problem of system closed-loop stability,this paper adopts PID control and phase lead compensation to improve closed-loop stability,which is validated by simulation.As for the problem of surplus torque caused by the position disturbance of loaded system,a feedforward control method based on the output angular velocity of loaded system is designed,which is validated by simulation.Being aimed at the problem of friction nonlinear problems,a compensation method based on dead-inverse is designed,which is validated by simulation.Finally,the integrated control effect of the disturbance torque suppression method is validated by dynamic loading performance simulation.In order to solve the problem of amplitude attenuation and phase lag of ETLS,an amplitude and phase control algorithm based on LMS is adopted in this paper,and the simulation is carried out to validate the performance.In order to improve convergence speed and steady-state accuracy of the amplitude and phase control algorithm,the amplitude and phase control algorithm based on Sigmoid function adaptive-step LMS is proposed,which is validated by comparative simulation.In order to validate actual control effects of disturbance torque suppression and dynamic loading precision improvement method,an ETLS experimental platform is developed in this paper,including hardware platform and user interface,on which a series of experiments are performed.Among them,the static loading experiment is carried out to validate the effect of the closed-loop controller and amplitude and phase control algorithm,the disturbance torque suppression experiment is performed to verify the effect of disturbance torque suppression method,the dynamic performance experiment is carried out to demonstrate the integrated effect of disturbance torque suppression and dynamic loading precision improvement method of this paper.