大型装备电液系统高精度鲁棒位置控制

阀控非对称缸电液系统具有参数不确定性和强外部扰动,导致系统鲁棒性和跟踪性能变差,控制难度增加。考虑外部扰动建立系统动态模型,为了提高系统鲁棒性和跟踪精度,提出自适应滑模控制策略,用滑模边界层厚度函数代替符号函数以减小系统颤振,构建扰动观测器来调整切换增益,进一步提高系统稳定性。引入可变边界层厚度函数,抑制变化负载对系统性能的影响。在固定负载和变化负载条件下进行实验验证,结果证明了所提出控制策略的有效性。

High Precision Robust Position Control for Large Equipment Electro-hydraulic System

The valve-controlled asymmetric cylinder electro-hydraulic system has parameter uncertainty and strong external disturbance, which leads to the deterioration of system robustness and tracking performance, and the control difficulty increases. The dynamic model of the system is derived considering the external disturbance. To improve the system robustness and tracking accuracy, an adaptive sliding mode control strategy is proposed. The symbolic function is replaced by the sliding mode boundary layer thickness function to reduce the flutter of the system. A disturbance observer is constructed to adjust the switching gain and further improve the stability of the system. Variable boundary layer thickness function is introduced to restrain the influence of variable load on system performance. Experiments were carried out under the conditions of fixed load and variable load. Experimental results demonstrate the effectiveness of the proposed control strategy.