负载口独立控制系统压力速度复合控制的耦合特性

Coupling property of pressure and velocity compound control in individual metering systems

以2个比例方向阀组成的负载口独立控制系统为研究对象,分析其压力与速度复合控制中的耦合特性.基于相对增益矩阵,推导反应其相互干扰程度强弱的耦合因子;理论分析其耦合程度与系统不同工作参数之间的关系,总结降低耦合程度的负载口独立系统设计及控制准则.通过仿真模型以及2t小挖系统试验测试,分析该系统的速度及压力特性,验证理论分析的正确性.针对耦合特性的准确分析可为改善负载口独立系统多变量控制性能提供了理论参考.

The coupling property of the speed and pressure compound control was investigated with individual metering control systems consisted of two proportional directional valves.Firstly,general descriptions of two-input two-output diagram for such control systems were transformed from its physical model.Accordingly,the coupling factor was derived using the relative gain array to describe the extent of coupling.It was advantageous to decrease the coupling relationship by tending this coupling factor towards 1.Based on this theory,the variation trends of the coupling degree were analyzed with respect to the different system parameters and control structures.Finally,the design and control criterions of individual metering systems were summarized.To verify the theoretical analysis results,the simulation and experiment in a 2tminiexcavator were implemented for analyzing the control characteristics,including velocity and pressure.The simulated and experimental results are both in accordance with theoretic analyzes.The results derived by the coupling factor can provide theoretical reference for improving the multivariable control performance of individual metering control systems.