| Spring torsion bar is the key mechanism of actuator load simulator.For a long time,the method of "using static standard" has been used,and there is no complete dynamic performance evaluation system.In order to ensure the loading accuracy of actuator load simulator,the dynamic and static performance evaluation of spring torsion bar is studied.In this paper,the spring torsion bar with a section length of 2.54 mm is taken as the research object.According to the formula,the sensitivity,maximum angle,maximum torque and other parameters of the torsion bar are derived,and the modal analysis of its natural frequency is carried out by using Solid Works.By analyzing the working principle of the actuator load simulator,the static calibration and dynamic calibration schemes of the spring torsion bar are proposed,and the functions of the performance evaluation system are defined.The basic structure,clamping device and limiting device of the system are designed by Solid Works,and the corresponding devices are processed.The servo motor,reducer,resolver,data acquisition card and other equipment are selected.Through analyzing the working principle of the servo system,the mathematical models of servo motor,current loop and speed loop are established,The step response method is used to identify the parameters of the servo system,the mathematical model of the control system is established,and the PID controller parameters are optimized by genetic algorithm.The system is stable in 69 ms,and the loading error is less than 0.01°,And can achieve amplitude 2°,At the same time,the frequency is0～14Hz;The upper computer software is programmed by Lab Windows/CVI to realize automatic calibration.By comparing the static calibration experimental results of manual and automatic calibration,the reliability of the designed system is verified;The static sensitivity of the torsion bar is 0.0227N·m/°,The working frequency band is 0～10Hz,and the passband is 0～11Hz.In the frequency band of 0～14Hz,there is no resonance phenomenon,which meets the working requirements. |
