基于改进NSGA-Ⅱ算法的RV减速器参数多目标优化研究

Multi-objective optimization of RV reducer parameters based on improved NSGA-II algorithm

旋转矢量(RV)减速器是工业机器人核心部件,对于机器人的性能起到关键作用。针对提升RV减速器综合性能的问题,从优化传动压力角的相关参数出发,对其结构参数(摆线轮齿数、短幅系数、针径系数、摆线轮宽度等)的多目标优化设计进行了研究。首先,研究了摆线轮平均压力角、传动效率和传动机构体积三者的相关参数之间的关系;然后,以此为优化目标,在摆线轮标准齿廓方程的基础上建立了多目标优化数学模型(该模型采用了基于非支配占优排序遗传学算法(NSGA-Ⅱ)改进了交叉算子系数生成的改进NSGA-Ⅱ算法);通过模型求解得到了帕累托最优解集,根据模糊集合理论的相关方法选取了最优解;最后,以某公司220-BX型RV减速器为例,进行了优化设计,建立了3D模型后进行了有限元分析,并加工出实验样机,进行了传动效率对比实验。实验结果表明:摆线轮平均压力角减小了7.19%,体积减小了11.1%,传动效率提高了4.9%。研究结果表明:该模型交互性强,能提高设计效率并节省设计开销,可为实际RV减速器工程优化设计提供参考。

Rotary vector(RV)reducer is the core component of industrial robots,which plays a key role in the performance of robots.In order to improve the comprehensive performance of RV reducer,the multi-objective optimization design of its structural parameters(such as the number of cycloidal gear teeth,short amplitude coefficient,pin diameter coefficient,cycloidal gear width,etc.)was studied starting from optimizing the relevant parameters of transmission pressure angle.Firstly,the relationship between the average pressure angle of the cycloidal gear,transmission efficiency,and the volume of the transmission mechanism were studied.Then,a multi-objective optimization mathematical model was established based on the standard tooth profile equation of the cycloidal gear as the optimization objective.The model adopts an algorithm based on non-dominated sorting genetic algorithm-II(NSGA-II),which improves the generation of cross operator coefficients namely improved NSGA-II.Then the Pareto optimal solution set was obtained by solving the model,and the optimal solution was selected according to the relevant methods of fuzzy set theory.Finally,taking a company s 220-BX RV reducer as an example to optimize the design,the 3D model was established for finite element analysis and the experimental prototype was fabricated for transmission efficiency comparison experiment.The experiment results show that the average pressure angle of the cycloid wheel decreases by 7.19%,the volume decreases by 11.1%,and the transmission efficiency increases by 4.9%.The research results show that this model has strong interactivity,can improve design efficiency,save design costs,and provide reference for practical engineering optimization design of RV reducer.