挖掘机电液流量匹配控制系统动态性能研究

Study on Dynamic Performance of EFMC System in Hydraulic Excavator

分析了液压挖掘机基于与负载压力无关流量分配(LUDV)多路阀的电液流量匹配控制(EFMC)系统的控制原理,建立了EFMC系统的液压挖掘机虚拟样机模型,采用实时检测油缸速度信号的反馈闭环控制方法提高流量匹配的精度。分别建立液压挖掘机EFMC系统动力学模型与液压系统模型并根据其实际工况进行联合仿真,研究了挖掘作业过程动态特性及节能特性。与传统的基于LUDV的负载敏感系统实验结果进行对比,结果表明:EFMC系统与传统负载敏感系统相比,改善了系统的动态响应特性和稳定性,泵的压力裕度明显减小,提高了系统的节能性,反馈闭环控制系统动态响应特性也明显得到提高。研究方法可为进一步研究挖掘机的动态性、节能性、稳定性提供理论依据和参考。

A virtual prototype of EFMC system in hydraulic excavator was constructed by analyzing the control principle of EFMC system based on lastdruck unabhangige durch-fluss verteilung （LUDV） multi-way valve, the accuracy of flow matching was improved by adopting feedback closedloop control method with real-time detection of oil cylinder speed signals. The dynamic and hydraulic models of EFMC system in hydraulic excavator were constructed respectively, and the co-simulation was conducted based on actual working conditions, the dynamic characteristics and energy-saving characteristics of mining operation process were studied,compared the experimental results with the traditional LUDV load-sensing system,the results indicate that compared with the load-sensing system,the dynamic response characteristics and stability performance of the EFMC system are improved,and the pressure margin is reduced obviously, the energy efficiency is improved, also the dynamic response characteristics of feedback closed-loop control system are improved. Theoretical basis and reference are provided for further research on dynamic characteristics, energy-saving characteristics and stability performance in excavator.