【摘要】 为实现热压系统上下料装置的轻量化设计，提出将响应面法和NSGA-Ⅱ算法相结合的多目标优化方法。以上下料机械手结构质量、最大变形和二阶模态固有频率作为优化目标，以机械手支撑立柱的壁厚、边长和取件手臂壁厚、宽度作为优化参数，进行参数化建模，采用Box-Behnken方法设计4因素3水平试验，并通过ANSYS Workbench有限元软件得到仿真结果。采用二阶响应面法，对目标函数与变量参数之间的非线性关系进行预测，并将预测数据与实际值比较，验证该方法具有良好的准确性和可行性。采用NSGA-Ⅱ算法对多目标优化的Pareto前沿解进行搜索，选择Pareto解集中的第55组解，即支撑立柱的壁厚为5 mm,边长为89 mm,取件手臂壁厚为7 mm,宽度为78 mm,宽度取整为80 mm。经过仿真证明，上下料机械手模型质量从307.89 kg减小到223.72 kg,减重比高达27.34%。优化后结构的最大变形量从0.394 mm增大到0.475 mm,满足最大变形量不超过1 mm的设计要求。二阶模态固有频率从47.57 Hz减小到46.19 Hz,降幅较小。运用ADAMS软件对上下料装置进行运动学仿真，得到机械手速度、加速度曲线，优化后该装置运动过程平稳，运动过程无明显冲击和振动。更多还原

【Abstract】 In order to achieve the lightweight design of hot-pressing system loading and unloading device, a multi-objective optimization method combining response surface method and NSGA-II algorithm was proposed. The optimal target was the structural mass, maximum deformation and natural frequency of second order modes of the loading and unloading manipulator. Taking the wall thickness and side length of the manipulator support column and the arm thickness and the width of the manipulator as optimization parameters, the parametric modeling was carried out, and the Box-Behnken method was used to design the experiment of 4 factors 3 levels. The simulation results were obtained according to ANSYS Workbench finite element software. The second order response surface method was used to predict the nonlinear relation between target function and variable parameters, and the prediction data was compared with the actual value, which proves the accuracy and feasibility of this method. The NSGA-II algorithm was used to search for the multi-objective optimized Pareto frontier solution, and the 55th Pareto solution set was selected for the 5 mm wall thickness, 89 mm side length, 7 mm arm thickness and 78 mm width which rounded to 80 mm. Simulation results show that the mass of the loading and unloading manipulator model decreased from 307.89 kg to 223.72 kg, with a weight loss ratio of 27.34 %. At the same time, the maximum deformation of the optimized structure was increased from 0.394 mm to 0.475 mm, meeting the design requirement of maximum deformation not exceeding 1 mm.The natural frequency of second order modes was decreased from 47.57 Hz to 46.19 Hz as a small decrease. ADAMS software was used to simulate the kinematics of the loading and unloading device, and the velocity and acceleration curves of the manipulator were obtained.After optimization, the movement process of the device is stable, without obvious impact and vibration.更多还原