自动穿鞋带机的机械夹爪多目标优化设计

为满足灵活穿鞋带过程中无空间干涉及较大的拉扯力需求,夹鞋带的机械夹爪需刚度足够且结构尽可能小巧, 为此,文中用有限元分析软件ANSYS Workbench对夹爪和连接件进行了静力分析,获取了夹爪和连接件的受力和变形情 况。为尽可能避免机械手与鞋面、夹具之间的干涉,运用优化模块Design Exploration,对夹爪和连接件进行了多目标优 化,在夹爪与连接件满足许用应力和最大位移变形的要求下,缩小了夹爪和连接件的结构尺寸。机械手静力分析表明： 机械手满足许用应力和最大位移变形的要求。     

降低挠性剑杆织机剑带消耗的几个途径

本文在分析了剑带易损的主要原因的基础上，提出了一些避免不必要损耗的方法。     

Throughput Optimization in Constant Travel‐Time Dual Gripper Robotic Cells with Parallel Machines

Constant travel‐time robotic cells with a single gripper robot and with one or more machines at each processing stage have been studied in the literature. By contrast, cells with a dual gripper robot, although more productive, have so far received scant attention, perhaps due to their inherent complexity. We consider the problem of scheduling operations in dual gripper robotic cells that produce identical parts. The objective is to find a cyclic sequence of robot moves that minimizes the long‐run average time to produce a part or, equivalently, maximizes the throughput. We provide a structural analysis of cells with one or more machines per processing stage to obtain first a lower bound on the throughput and, subsequently, an optimal solution under conditions that are common in practice. We illustrate our analysis on two cells implemented at a semiconductor equipment manufacturer and offer managerial insights for assessing the potential productivity gains from the use of dual gripper robots.     

Approximations to Optimal k‐Unit Cycles for Single‐Gripper and Dual‐Gripper Robotic Cells

We consider the problem of scheduling operations in bufferless robotic cells that produce identical parts using either single‐gripper or dual‐gripper robots. The objective is to find a cyclic sequence of robot moves that minimizes the long‐run average time to produce a part or, equivalently, maximizes the throughput. Obtaining an efficient algorithm for an optimum k‐unit cyclic solution (k ≥ 1) has been a longstanding open problem. For both single‐gripper and dual‐gripper cells, the approximation algorithms in this paper provide the best‐known performance guarantees (obtainable in polynomial time) for an optimal cyclic solution. We provide two algorithms that have a running time linear in the number of machines: for single‐gripper cells (respectively, dual‐gripper cells), the performance guarantee is 9/7 (respectively, 3/2). The domain considered is free‐pickup cells with constant intermachine travel time. Our structural analysis is an important step toward resolving the complexity status of finding an optimal cyclic solution in either a single‐gripper or a dual‐gripper cell. We also identify optimal cyclic solutions for a variety of special cases. Our analysis provides production managers valuable insights into the schedules that maximize productivity for both single‐gripper and dual‐gripper cells for any combination of processing requirements and physical parameters.