一种机器人第七轴系统的优化设计方案

A Global Optimization Method for the Seventh Axis System of Robot

针对机器人竖直加工范围较小以及机器人第七轴的弯扭复合变形问题,将响应面法与结构拓扑相结合,提出一种抬高式重载机器人第七轴全局优化设计方案。该方案根据轨道交通车体表面打磨产线的设计需求进行第七轴结构设计,由机器人加工极限位姿建立七轴系统几何模型,并根据单元理论选定单元,建立基于虚位移的线性有限元方程,进行静力分析求解。根据分析结果,将第七轴系统划分为基座与加高座结构件两个模块,分别将其关键尺寸参数化,并通过Box-Behnken方法设计试验采样,建立基于多元二次线性回归方程的二阶响应面模型,结合输出的灵敏度分析结果建立强响应因素3D响应云图,采用遗传算法分别对各模块响应面求最优Pareto解,根据易加工原则,确定关键尺寸,完成尺寸优化。最后对加高座结构件模型进行拓扑优化分析,去除设计域冗余材料,结合实际加工情况,对拓扑结果进行模型重构,得到最优设计方案。

In order to solve the problem of the small vertical machining range and the complex bending and twisting deformation of the seventh axis of the robot,a global optimization design method of the lifting heavy-duty robot seventh axis is proposed by combining the response surface method with the structural topology.The structure was designed from the requirements of the rail vehicle body surface grinding production line,the geometric model of the seven axis system is established by the robot machining limit position,the elements are selected according to the element theory,and the linear finite element equation based on the virtual displacement is established for static analysis.According to the analysis results,the seventh axis system is divided into two modules,the base and the heightening seat.The key dimensions are parameterized,and the second-order response surface model based on the multiple quadratic linear regression equation is established by using the Box-Behnken method to design the test samples.Combined with the output sensitivity analysis results,the strong response factor 3D response cloud chart is established,and the genetic algorithm is used for each module to find the optimal Pareto solution.According to the principle of easy machining,the key dimension is determined and the dimension is optimized.Finally,the topology optimization analysis of the structure model of the heightening seat is carried out to remove the redundant materials in the design domain.Combined with the actual processing situation,the topology results are reconstructed to obtain the best design scheme.