基于变溢流压力的电液机械臂节能控制策略

Variable Overflow Pressure Based Energy Saving Control for an Electro-hydraulic Manipulator

针对电液系统能量效率过低的问题,以一款多自由度液压机械臂为研究对象,提出了一种可变溢流压力的非线性控制策略,实现电液机械臂位置跟踪的同时,降低系统的能量消耗。同时考虑了液压系统动态特性与机械臂动力学,建立了电液机械臂的数学模型,基于该模型搭建了动态面非线性控制器。通过模型中位移与压力的关系,反推出理想位移对应的理论溢流压力,由该压力控制比例溢流阀,实现可变溢流压力。通过仿真对比分析,该控制策略在保证液压机械臂位置跟踪精度的同时,与传统的定溢流压力相比,降低了能耗,从而验证了该方法的有效性。

This paper proposes an energy-saving based nonlinear control method with variable overflow pressure for a multi degree-of-freedom hydraulic manipulator to improve the joint position tracking performance and reduce the energy consumption of the system.Considering the dynamic characteristics of the hydraulic system and manipulator simultaneously,the mathematical model of the electro-hydraulic manipulator is established,and a dynamic surface nonlinear controller is built based on this model.Relying on the relationship between displacement and pressure,the theoretical oil pressure corresponding to the ideal displacement is derived,and the proportional relief valve is controlled by this pressure to achieve variable relief pressure.The simulation results show that the proposed control strategy not only ensures the displacement tracking accuracy of the hydraulic manipulator,but also reduces energy consumption compared with the traditional constant overflow pressure,which verifies the effectiveness of the proposed method.