Loading Performance Analysis And Control Strategy Research Of Electric Linear Load Simulator

The electric linear load simulator(ELLS)is widely used in aerospace,weaponry and ships and other fields,it is an important hardware-in-the-loop simulation equipment.ELLS can simulate the constant or alternating load experienced by the linear actuator in actual working conditions,so the mechanical and control performance of the actuator can be tested.Aiming at the problems of low loading precision,narrow bandwidth and poor anti-interference ability in ELLS,the ELLS is further studied.The mechanism model of ELLS and an electric linear actuator are built.The simulation model of ELLS is established using AMESim,and a co-simulation model based on AMESim and SIMULINK is established,providing a simulation platform for later controller design.The causes of surplus force in ELLS are analyzed,and the existence of surplus force and its influence on ELLS are verified by simulation and experiment.The influence of structural parameters on ELLS is analyzed.The nonlinear model of ELLS is built,and the causes of loading waveform distortion caused by friction and gap and their influence on ELLS are analyzed.The open-loop frequency characteristics of ELLS are analyzed,phase-lag compensation and force closed loop PID control are introduced to ensure the stability and loading accuracy of the system.To suppress surplus force,force command feedforward compensation and improved disturbance feedforward compensation strategy are proposed,and the simulated results verify the feasibility of the designed controller.Aiming at the problem of parameter uncertainty and surplus force in ELLS,a back-stepping adaptive controller is designed.The simulated results show that,compared with the traditional PID controller,the proposed controller can suppress the disturbance of the actuator on ELLS and improve the loading accuracy.The design of hardware and software for ELLS is completed.On this basis,static loading experiments,surplus force experiments,dynamic loading experiments and loading test experiments on the actuator are completed.The experimental results show that the dynamic and static loading accuracy of ELLS satisfy the “double ten index” within the specified frequency,the system has hign anti-interference ability,and can realize loading tests for linear actuators.