Multicriteria Optimization Design for End Effector Mounting Bracket of a High Speed and Heavy Load Palletizing Robot
Multicriteria Optimization Design for End Effector Mounting Bracket of a High Speed and Heavy Load Palletizing Robot
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DOI：
10.1155/2018/6049635
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发表时间：
2018-04
影响因子：
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通讯作者：
Ying He;J. Mei;Jiawei Zang;Shenglong Xie;Fan Zhang
中科院分区：
文献类型：
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作者：
Ying He;J. Mei;Jiawei Zang;Shenglong Xie;Fan Zhang
末端执行器安装支架是高速重载码垛机器人的重要承载部件，它位于机器人回转半径的最远点，经常在起停、切换方向、加减速运动等复杂环境下工作，因此对其结构进行优化设计，有利于提高机器人系统的动态性能，降低能耗。首先，建立了末端执行器安装支架的有限元模型，并通过模态试验结果与有限元模型的对比分析，验证了模型的准确性。其次，通过模态分析、振动响应试验、频响分析和静力分析，确定了以质量最小、最大应力最大、变形最大、一阶固有频率最大为优化目标，通过灵敏度分析选取设计变量，以其取值范围为约束条件，利用Box-Behnken设计和响应面法建立了目标函数的近似模型，并对其可靠性进行了验证；为了确定各优化目标的权重，提出了一种基于有限元分析的层次分析法(FEA+AHP)，以提高判断矩阵的客观性；随后，利用上述方法建立了多目标优化数学模型。再次，利用NSGA-II算法对多目标优化问题进行求解，得到优化结果。最后，对优化模型和初始模型进行了对比分析，结果表明，在最大应力和变形均在允许范围内的情况下，质量减少了17.8%，一阶固有频率提高，结构的振动响应特性得到明显改善。验证了该优化设计方法的有效性。
End effector mounting bracket is an important load bearing part of high speed and heavy load palletizing robot, which is located at the most distant point in robot rotation radius and frequently works in complex conditions such as start-stop, switch direction, and acceleration and deceleration motion; therefore, optimizing design for its structure is beneficial to improve the dynamic performance of robotic system and reduce energy consumption. Firstly, finite element model of end effector mounting bracket was established, and its accuracy was verified by contrastive analysis of modal test result and finite element model. Secondly, through modal analysis, vibration response test, frequency response analysis, and the static analysis, taking inertia into account, the mass is minimized, the maximal stress is minimized, the maximal deformation is minimized, and the first natural frequency is maximized as the optimization objectives are determined; the design variables were selected by sensitivity analysis, taking their value range as the constraint conditions; approximation models of objective functions were established by the Box-Behnken design and the response surface methodology, and their reliability was validated; to determine weighting factor of each optimization objective, an analytic hierarchy process based on finite element analysis (FEA + AHP) method was put forward to improve the objectivity of comparison matrix; subsequently, the multicriteria optimization mathematical model was established by the methods mentioned above. Thirdly, the multicriteria optimization problem was solved by the NSGA-II algorithms and optimization results were obtained. Finally, the contrastive analysis results between optimized model and initial model showed that, in the case of the maximum stress and deformation within allowable values range, the mass reduction was 17.8%; meanwhile, the first natural frequency was increased, and vibration response characteristics of the entire structure were improved significantly. The validity of this optimization design method was verified.