An Optimal Tolerance Design Approach of Robot Manipulators for Positioning Accuracy Reliability
提出一种机器人操作器公差设计方法，通过运动学与特征分解构建定位精度性能函数，结合卡方近似和数值积分计算可靠性，并用改进遗传算法优化公差组合，在控制制造成本下最小化失效概率。
This paper proposes a novel tolerance design method for robot manipulators to select the optimal tolerances of kinematic parameters. A tolerance optimization model is presented to minimize the failure probability of positioning accuracy with the constraint of manufacturing cost. First, the performance function of positioning accuracy is constructed by performing the differential kinematics and eigen-decomposition concepts, which further combines the chi-square approximation and numerical integration methodologies to calculate the positioning accuracy reliability. An improved genetic algorithm is then presented based on the diversity crossover and differential mutation strategies to optimally and efficiently solve the tolerance design model. The applicability and performance of the proposed method are validated by the tolerance design of a 6-degree-of-freedom robot manipulator. The comparison with the existing techniques illustrates that the proposed method (i) processes better accuracy and efficiency in positioning accuracy reliability analysis; (ii) obtains a tolerance combination of kinematic parameters with a higher positioning accuracy reliability. The proposed method contributes to the optimal tolerance range selection and design of robot manipulators and other moving parts of machinery.