液压驱动型四足机器人电液伺服控制系统仿真建模与实验分析

Modeling and Analysis of an Electro Hydraulic Servo System of a Quadruped Robot

摘要:

复杂的作业环境和艰巨的作业任务使液压驱动型四足机器人对其伺服系统的精度、速度和力量均比一般机器人在普通情况下有更高的要求。为掌握液压驱动型四足机器人在多种路况下行走时各液压缸的受力情况以及液压系统内流量、压力的变化情况,需要对其虚拟样机进行机械动力系统和液压伺服系统的联合仿真,定性分析电液伺服系统位置、速度等被控对象的特性,并分析PID控制器在四足机器人伺服控制方面的特性与不足。针对传统控制算法在四足机器人控制存在的短板问题,设计了一种非对称前馈补偿模糊自适应PID算法,并利用物理样机进行了实际验证。实验结果为四足机器人电液伺服控制系统硬件、软件和控制算法的设计与优化指明了方向,还为研究四足机器人平稳步态控制策略提供了决策依据和数据支持。

Abstract:

Working heavily in complex environment requires the electro-hydraulic servo systems of hydraulic quadruped robots higher demands in precision, speed and strength than ordinary systems. For learning the force situation of the cylinders and the flow/pressure fluctuation of the hydraulic system in multiple situations, it is a need to make up a co-simulation model for machinery dynamics and hydraulic servo systems, which helps for qualitative analysis of location and velocity features of the electro-hydraulic servo systems, and also analyzing the characteristics and limitations of PID controller in robot servo control. Based on solving the shortcomings of ordinary control algorithm, a fuzzy adaptive PID control algorithm with asymmetric feedforward compensation was established to meet the electro-hydraulic servo characteristics, which had been verified effective by physical prototype test. The conclusions indicate the design of hardware/software and motion control algorithm with decisions and data supports for smooth gaits control strategy of the electro-hydraulic quadruped robot.