非对称液压缸对称性控制

Symmetric control of asymmetric cylinder

阀控非对称缸两个运动方向上系统的开环增益及某些参数的不同,使得两个方向上的动态特性不对称,这种本质上的非线性和非对称性给系统控制带来困难.PБ-211机器人后3个关节是对称阀控制非对称液压缸伺服系统,为了使机器人运行平稳和提高控制精度,在控制中必须加以适当补偿.在分析非对称液压缸工作原理基础上,考虑液压缸伸出和缩回性能不同,提出了模型参考变增益自适应控制算法对非对称液压缸进行补偿.该算法包括单神经元自适应PID控制、模型参考自适应控制和输出增益的自动调节3个部分.仿真分析和实验表明该算法可以基本实现非对称液压缸的对称性控制,较普通PID控制算法具有明显优势.

The open loop gain and some parameters are different on the two moving directions of symmetric valve controlling asymmetric cylinder system. This difference leads to dynamic performance asymmetry on the two moving directions. The natural nonlinear and asymmetric system is difficult to control. The last three joints of PB-211 robot are controlled by symmetric valve controlling asymmetric cylinder system. To make the robot moving smoothly and improve the control precision, the control system must have proper compensation. After analyzing the asymmetric cylinder and taking the difference of protrusion and retraction into account, a new control algorithm, model reference self-tuning gain adaptive algorithm, was put forward. The new algorithm includes adaptive single neuron PID, model reference adaptive algorithm and self-tuning output gain. Simulations and experiments illustrate that the new control algorithm can compensate the asymmetric cylinder system, which is better than the command PID algorithm.