负载口独立控制阀控非对称缸压力跃变消除方法研究

Elimination Method of Asymmetric Hydraulic Cylinder Pressure Jump Based on Dual-spool Independent Metering Valve

针对液压同步控制系统中非对称缸换向时产生的压力跃变导致同步控制系统振荡甚至不稳定问题,提出一种基于负载口独立控制阀控非对称缸系统的换向压力跃变消除方法。分析了传统阀、非对称阀和负载口独立控制阀控非对称缸系统产生压力跃变的机理。在AMESim中搭建传统阀与负载口独立控制阀控非对称缸系统模型,在不同系统压力和给定信号下,对比分析了两种系统液压缸位置跟随及换向时两腔压力跃变情况。搭建了负载口独立控制阀控非对称缸系统实验台,验证了该方法的有效性。仿真与实验结果表明,采用负载口独立控制阀控非对称缸系统通过模糊自适应控制算法可以很好地实现位置跟随;可以完全消除非对称缸换向时的压力跃变,减小系统抖动,使得系统动作更加平稳;当液压缸以方波动作时,换向时压力冲击较正弦波动作时大。

In hydraulic synchronous control system,the pressure jump generated by asymmetric cylinder during changing the direction results in the oscillation and even instability of the synchronous control system.Aiming at this problem,a method for eliminating pressure jump based on the dual-spool independent metering valve controlling asymmetric cylinder system was proposed.Firstly,the mechanisms of pressure jump generated by asymmetric cylinder were analyzed,in which the asymmetric cylinder was respectively controlled by traditional valve,asymmetric valve and dual-spool independent metering valve.Secondly,the models of traditional valve controlling asymmetric cylinder system and the dual-spool independent metering valve controlling asymmetric cylinder system were built in AMESim.Then the position following and the pressure jump in the traditional valve controlling asymmetric cylinder system and dual-spool independent metering valve controlling asymmetric cylinder system were compared and analyzed under different system pressures and different given signals.Finally,the experimental platform of the dual-spool independent metering valve controlling asymmetric cylinder system was built to verify the effectiveness of the proposed method.Simulation and experimental results showed that the asymmetric cylinder system controlled by the dual-spool independent metering valve can realize position following well through the fuzzy adaptive control algorithm.When the asymmetric cylinder changed direction,the pressure jump can be completely eliminated,reducing oscillation of the system,and made the system more stable.When the hydraulic cylinder was operated by square wave,the pressure impact was larger than that when the sine wave was operated.This method was beneficial to achieve good synchronous control effect.