摘要
针对关节式同步带减速机械臂精度可靠性差、制造成本高等问题,对机械臂误差建模、精度可靠性分析、精度优化设计进行了研究。利用柔性多体理论,建立了考虑机械臂杆长、关节间隙和同步带柔性耦合等因素的精度误差模型,利用实验手段获得了模型不确定性参数,利用所建立的可靠性模型应用一阶二次矩法进行了可靠性分析;对比了计算可靠度和实测可靠度验证模型准确性,开展了以灵敏度分析为基础的可靠性优化过程,建立了以制造成本最低为优化目标,满足精度可靠度要求为约束的优化模型;利用Matlab中遗传算法工具箱进行了机械臂精度优化设计。研究结果表明:未优化前X轴和Y轴可靠度基于模型计算和实验测试的相对误差为0. 16%和0. 32%,大臂和小臂加速度为主要误差因素;经优化后X、Y轴可靠度分别提高到了99. 71%和99. 78%,且与经验设计相比,制造成本降低27. 92%,为关节式同步带减速机械臂设计制造提供了理论依据。
Aiming at the low accuracy reliability and the high manufacturing cost of the joint type of synchronous belt deceleration mechanical arm,the robotic arm error modeling,precision reliability analysis and precision optimization design were studied.An accuracy error model considering the length of arm,the joint clearance and the flexible coupling of synchronous belt were built by using flexible multibody theory, the model uncertainty parameters were obtained through the experimental method.Based on the reliability of the model which was developed by applying first order second moment method for reliability analysis.By comparing the comparative calculation accuracy reliability and measurement reliability,the correctness of the model was certified.Based on the sensitivity analysis of reliability and optimization process,the constraint optimization model which was based on the lowest manufacturing cost as the objective accuracy and reliability was built,then the genetic algorithm in Matlab toolbox was used for the design of mechanical arm precision optimization .The results indicate that the relative error of calculation accuracy reliability and measured reliability is 0.16%and 0.32%,and the acceleration of the large arm and the small arm is the main error factor.After optimizing,the X,Y axis reliability is increased to 99.71%and 99.78%respectively,the manufacturing costs is reduced by 27.92%comparing with the experience in design,for joint type synchronous belt provides the theory basis for design and manufacture of mechanical arm deceleration.
作者
夏力
罗路平
徐琦
XIA Li;LUO Lu-ping;XU Qi(Key Laboratory of Ministry of Education,Zhejiang University of Technology,Hangzhou 310014,China)
出处
《机电工程》
CAS
北大核心
2018年第12期1297-1303,共7页
Journal of Mechanical & Electrical Engineering
基金
国家自然科学基金资助项目(51475425)
浙江省自然科学基金青年基金资助项目(LQ18E050014)
关键词
关节式同步带减速机械臂
耦合误差模型
关节间隙
同步带柔性
精度优化
articulated belt deceleration manipulator
coupling error model
joint clearance
timing belt flexibility
accuracy optimization
