一种新型可调整闭链多足机器人的设计与分析

Design and Analysis of a Novel Adjustable Closed-chain Multi-legged Robot

针对单自由度闭链腿部机构足端轨迹单一导致机器人的地面适应性不足,提出一种新型可调整闭链腿部机构。以Klann六杆机构为构型基础,增加一个使其机架铰链转动的自由度,实现了铰链位置的调整。用此方法获得足端轨迹的连续性变化,从而可在纵向上提高抬腿高度以增强越障能力,同时可在横向上改变跨步距以实现逼近目标点的规划,并且还可通过切地角度的调节降低爬坡过渡段的足端冲击。此种腿部机构在行走时由一个电动机驱动,可维持其单自由度特性,在少驱动数目、高结构刚度以及大承载能力方面具有性能优势。进行腿部机构的构型设计、运动学分析以及以最大抬腿高度为目标的参数优化。在此基础上构建八足机器人,建立足端轨迹簇并进行轨迹的参数分析,开展行走策略的研究。制作一台样机,针对典型地面环境开展适应性试验,验证了设计的可行性。

The single foot trajectory of the single-degree-of-freedom close-chain leg mechanism leads to insufficient ground adaptability.Addressing this,a novel closed chain adjustable leg mechanism is proposed.Based on the six-bar Klann mechanism,one degree of freedom is added to realize the adjustment of the frame hinge position.By this way,the continuous change of foot trajectory can be obtained.The height of the legs can be increased longitudinally to enhance the obstacle crossing ability,and the stride distance can be changed in the transverse direction to achieve the plan of approaching the target point,and the slope-climbing impact can be reduced during the transition section as well.This kind of leg mechanism is driven by an electric motor while walking,which maintains its single-degree-of-freedom characteristics with fewer actuators,high structural stiffness and large carrying capacity.The configuration design,kinematics analysis and parameter optimization of the leg mechanism ar e carried out.Further the eight-legged robot is constructed.The foot trajectory cluster is established.The trajectory parameters and the walking strategies are analyzed and studied.The feasibility of the design is verified by fabricating a prototype and car rying out adaptability experiments in typical ground environment.