线性摩擦焊机电液伺服施力系统动态特性

为分析线性摩擦焊机电液伺服施力系统对焊接过程关键参数压力和速度的动态响应特性,判断系统的控制品质,对滑台压力进行了闭环控制下的时域阶跃响应实验,得到了时域响应曲线.对滑台速度和压力分别进行了开环和闭环控制下的频域特性实验,借助Matlab平台绘制出速度和压力的响应Bode图,通过逼近的方法得到系统对于开环速度和闭环压力信号的传递函数.实验结果表明,系统压力闭环时域响应平均纯滞后时间为2.6 ms,平均延迟时间为17.4 ms,平均稳态误差0.61%,平均超调量1.83%,系统响应速度快,超调量小,稳态控制精度高;速度开环工作频宽为9 Hz,压力闭环工作频宽为22 Hz,系统稳定性较高.

Dynamic Characteristics of Electro-Hydraulic Servo Load System of Linear Friction Welding Machine

In order to test the dynamic response characteristics of the pressure and velocity,the key welding parameters in electro-hydraulic servo load system of linear friction welding machine,time domain step response experiments of pressure were implemented under closed loop control,and time domain response curves were obtained.Frequency domain characteristics experiments of velocity and pressure were implemented under open loop and closed loop control respectively.Pressure and velocity response Bode graphs were made with Matlab,and signal transfer functions of open loop velocity and closed loop pressure were obtained in the method of signal approximation.The results show that in the experiments of pressure time domain response under closed loop control,the average pure time delay is 2.6 ms,the average delay time is 17.4 ms,the average steady-state error is 0.61%,the average overshoot is 1.83%,which means the response is swift,the overshoot is low and the steady-state precision is high.The working frequency width of velocity under open loop control is 9 Hz;the working frequency width of pressure under closed loop control is 22 Hz.The system stability is relatively good.