六足机器人整机运动学分析及构型选择

六足机器人整机构型设计和整机运动学模型是机器人样机研制和行为控制的基础。利用GF集理论阐明了六足机器人整机构型设计的实质即为解决机械腿在机身平台上的布局问题,并基于仿生学原理给出了5种整机构型。介绍了一种三自由度并联驱动腿部机构,并利用闭环矢量链及求导的方法建立了基于该腿部机构的六足机器人整机运动学模型。本文给出了六足机器人整机运动学理论及仿真算例,推导出了速度、加速度的理论值及仿真值的拟合图。拟合结果表明:角速度、角加速度的理论值与仿真值的最大误差量级分别为10~(-2)(°)/s和10~(-3)(°)/s~2,验证了理论模型的正确性。基于该理论模型,绘制了不同构型下该并联驱动腿的六足机器人的工作空间分布图,选择了工作空间较大的两种整机构型,并对这两种构型下的六足机器人的运动学性能进行对比分析,选择了一种能够更好发挥该腿部机构综合运动能力的整机构型。本文的研究为该六足机器人的后续研究奠定了理论基础。所使用的整机运动学建模方法对其他六足机器人也实用。

Kinematics analysis and configuration selection of whole machine of hexapod robot

The whole machine configuration design and kinematics model of hexapod robot are foundation of robot prototype development and behavior control.GF set theory is adopted to illustrate that essence of whole machine configuration design of hexapod robot is to solve layout problem of mechanical legs on body platform,and five types of whole machine configurations are given based on bionics principle.A kind of parallel-driven leg mechanism with three degree of freedom is introduced,and kinematics model of whole machine of hexapod robot based on this leg mechanism is established with method of close-loop vector chain and derivation.Kinematics theory and simulation example of whole machine of hexapod robot are respectively given,and fitting pictures of theory values and simulation values for speed and accelerated speed are derived.Fitting results indicate that maximum error orders of theory angular speed and angular accelerated speed with those of simulated are respectively 10-2 (°)/s and10-3 (°)/s2,which verifies correctness of theoretical model.Work space distribution maps of hexapod robot based on this parallel-driven leg under different configurations are drawn,and two types of whole machine configurations having large work space are selected.Kinematics performance of hexapod robot under these two configurations is compared,and a whole machine configuration to better exert comprehensive athletic ability of this leg mechanism is selected.This research can lay theoretical basis for the following research of this hexapod robot.Kinematical modeling method of whole machine used is also practical for other hexapod robots.