新型2URU-2RSS并联机器人机构运动学分析多目标优化
Kinematic Analysis and Multi-objective Optimization of Novel 2URU-2RSS Parallel Robot Mechanism
王娜 1于敏 1张永选 1李强2
作者信息
- 1. 豫章师范学院数学与计算机学院,江西南昌 330103
- 2. 江铃汽车股份有限公司,江西南昌 330200
- 折叠
摘要
提出一种半对称的 2URU-2RSS并联机器人机构,该机构由 4 条支链构成,结构紧凑且具有较好的转动性能.根据方位特征集理论研究机构的运动性质和自由度性质.基于杆长约束条件,建立运动学方程,得出位置正解和逆解,并以2 组数值算例分析验证运动方程解的正确性.同时通过规划空间的螺旋线运动,研究驱动副φi 的变化,以此验证机构的运动性能.利用雅克比矩阵确定正、逆向奇异构型,并分析机构的理论工作空间以及可达工作空间内的动平台最大、最小转动角的空间分布图谱.研究不同结构参数对性能的影响趋势.最后,提出任务工作空间内的整周回转能力利用率作为反映实际转动能力评价指标,建立任务工作空间利用率η和整周回转能力利用率μ作为优化目标.选择NSGA-II算法得到Pareto最优尺度参数解,并进行算例分析验证目标模型的有效性.结果表明:任务工作空间内的整周回转能力指标最高可达 99%以上,任务工作空间利用率最高可以提升至 40%;机构的整体性能得到极大改善.
Abstract
A semi symmetric 2URU-2RSS parallel robot mechanism was proposed,consisting of 4 branch chains,with a compact structure and good rotational performance.According to the theory of directional feature sets,the motion and degree of freedom properties of the mechanism were studied.Based on the rod length constraint,a kinematic equation was established,and the forward and inverse po-sition solutions were obtained.Two sets of numerical examples were used to analyze and verify the correctness of the motion equation so-lution.At the same time,by planning the spiral motion of the space,the change of the driving pairφi was studied,so as to verify the mo-tion performance of the mechanism.The Jacobian matrix was used to determine the forward singular configuration and the reverse singu-lar configuration,and the spatial distribution patterns of the maximum and minimum rotation angles of the moving platform in the theo-retical workspace and the reachable workspace of the mechanism were analyzed respectively.The influence trend of different structural parameters on the performance was studied.Finally,the utilization rate of the full cycle rotation capacity in the task workspace was pro-posed as an evaluation indicator to reflect the actual rotation capacity,and the task workspace utilization rateηand the full cycle rotation capacity utilization rate μwere established as optimization objectives.NSGA-II algorithm was selected to obtain the Pareto optimal scale parameter solution,and numerical analysis was conducted to verify the effectiveness of the target model.The results show that the index of the whole cycle turning ability in the task workspace can be up to 99%,and the utilization rate of the task workspace can be up to 40%.The overall performance of the mechanism is greatly improved.
关键词
并联机器人/运动学/理论工作空间/任务工作空间/转动能力/评价指标Key words
parallel robot/kinematics/theoretical workspace/task workspace/rotational capacity/evaluating indicator引用本文复制引用
出版年
2024
NETL
NSTL
万方数据