新型周转式轮腿机器人运动分析与步态规划

Motion analysis and gait planning of a novel revolving wheel-legged robot

针对现有四足机器人越障能力不足及越障不平稳的问题,提出一种通过轮系传动来实现高越障和质心平稳的新型轮腿式机器人。该机器人髋关节部位采用轮系构型,扩大机器人腿部运动范围,克服越障高度与机器人腿部长度之间的矛盾,同时通过合理的步态规划保证机器人质心的运动轨迹平稳。基于Denavit-Hartenbery (D-H)法建立机器人运动学模型,从而构建机器人腿部末端与越障高度的映射关系,根据此映射关系得出最佳越障高度为自身腿长高度的66.4%,基于重心地面投影点(CoG)静态稳定性判据对机器人进行越障步态及行走静步态规划,并通过仿真实验验证此步态下质心的稳定。搭建实验样机,进行机器人越障实验,进一步验证所提轮腿机器人越障高度高及越障过程质心平稳的有效性和可行性。

To address the problems of the existing quadruped robot's insufficient obstacle surmounting ability and unstable obstacle surmounting,a new wheel-legged robot was proposed to achieve high obstacle surmounting and stable centroid through wheel-train transmission.Adopting the wheel configuration,the hip joint of the robot expands the range of motion of the robot leg,overcomes the contradiction between the height of obstacle crossing and the length of the robot leg,and ensures the smooth motion trajectory of the robot centroid through reasonable gait planning.A kinematics model of the robot was established based on Denavit-Hartenbery(D-H)method,and the mapping relationship between the end of the robot leg and the height of obstacle crossing was constructed.According to the mapping relationship,the optimal height of obstacle crossing was 66.4%of the length of the robot leg.The static stability criterionv center of gravity(CoG)is used to plan the obstacle crossing gait and static walking gait of the robot,and the stability of the center of mass under this gait is verified by simulation experiments.An experimental prototype was built and the obstacle crossing experiment was carried out,which further verified the effectiveness and feasibility of the high obstacle crossing height and stable centroid of the proposed wheel-legged robot.