基于CPG网络的六足机器人行走步态规划方法地研究.pdf

Classified Index: : for the Master Degree in EngineeringGAIT PLANNING METHEDFOR HEXAPOD ROBOT BASED ON CPG RHYTHM WORKCandidate:LIU WeiHuaSupervisor:Associate Prof. Xu WenFu Academic Degree Applied for:Master of EngineeringSpeciality:Mechatronics EngineeringAffiliation:Shenzhen Graduate SchoolDate of Defence:December, 2012Degree-Conferring-Institution:Harbin Institute of Technology摘要-I-摘要足式机器人具有移动灵活、机动性良好和能耗较低的特点,可以适应崎岖的地面结构,其研究方向又分为四足、六足和八足,其中六足机器人在稳定性上比四足机器人高,而在控制方式上又比八足机器人简单,因此本文将以六足机器人为对象,对其控制步态行走和避障步态进行研究。文中首先分析六足机器人三角步态、四足步态和波动步态各自的特点和稳定性,以及三种步态中机器人重心与相应支撑多边形的关系,并对腿部进行正运动学计算,分别采用六次多项式和五次多项式约束条件分别规划足端摆动轨迹和支撑轨迹。为了实现机器人行走中腿部的控制,采用Matsuoka的数学模型建立CPGs(Central Pattern Generators)节律运动的振荡器,该振荡器属于非线性耦合四阶系统,具有强耦合、高维数和多变量的特点,通过傅里叶级数推导波形输出与模型参数之间的近似关系,采用观察法和相平面法进行参数分析和调整。通过输出信号与机器人腿部关节舵机运动范围建立映射关系,并采用离线的方式验证该模型输出的可行性,最后建立整体CPGs振荡器的关节拓扑控制结构。为预估六足机器人按所规划轨迹运动过程中关节的驱动力矩,采用ADAMS软件建立其动力学模型,将所规划的数据导入后,开展了动力学仿真研究。跨越障碍是六足机器人应用的关键问题之一,因此论文还研究了避障和踏空两种步态,通过腿部的二次规划,即足端遇到障碍物或没有支撑点时在原来规划曲线发生断点的位置前向扩大运动幅度再一次规划运行轨迹的方式来实现。最后,利用实际六足机器人样机对通过CPGs网络控制的三角步态和四足步态以及通过二次规划实现的越障和踏空步态进行了验证。关键词:六足机器人;运动规划;步态;CPG节律运动;避障目录-II-AbstractLeg-type robot which has good mobility and lower energy pared to crawler and wheeled robots can adapt to rugged structure of the ground and eobstacles. Leg-tpye robot research contains three directions, such as quadruped robot, hexapod robot and spider robot. Hexapod robot possesses more stable character than qudruped robot and more flexible control than spider robot, therefor the purpose of this thesis is aimed at the study of a hexapod robot, which fouce on gait, control strategy and obstacle three types of gait including triangle gait, quadrupedal gait and wave gait have been analysed with respect to characteristics and stability, and the relationship between gravity center of robot and the corresponding support polygon as well as forward kinematics has been c