Integration of Parameter and Tolerance Design with Off-Line Quality Control

小行星9503935 本计画针对机械系统设计之效能、品质与可制造性，在设计过程之早期阶段，整合参数设计与公差分配。 该项目包括三个主要任务：（1）用形位公差表示法描述公差，建立具有运动链的机械装配模型和形状公差模型;（2）建立机械系统的稳健设计方法，识别系统的性能特征和导出系统灵敏度指标;以及（3）通过确定性能、可制造性和成本降低的公差分配来综合性能和可制造性的公差，并实现性能、质量和可制造性的最佳决策。 该方法将在一个案例研究中得到证明。 本研究结果提供了一个有效的方法来了解公差对性能的影响。 该方法处理整个系统而不是单个链路的公差灵敏度。 然而，它允许一个明确地确定每个单独的公差对性能质量的相对影响，并选择一个系统的公差不太敏感。 对于机构综合，它适用于任何类型的综合问题，包括功能，路径和运动生成或有限，无穷小和混合位置。 其有效性保持不变，无论所需位置的数量或链接的数量。 总之，本研究提出了一种方法，使设计人员能够在设计过程的早期阶段同时大力追求最佳参数设计和公差分配。 因此，实现了制造成本降低、快速产品设计和原型制作以及离线质量控制。

9503935 Ting This project addresses the issue of mechanical system design for performance quality and manufacturability by integrating parameter design and tolerance allocation at an early stage in the design process. The project includes three main tasks: (1) characterizing tolerances by geometric tolerance representation, modeling of mechanical assemblies with kinematic chains, and modeling of form tolerances; (2) developing a robust design methodology for mechanical systems that identifies performance characteristics and derivation of system sensitivity indices; and (3) synthesizing tolerances for performance and manufacturability by determining tolerance allocation for performance, manufacturability and cost reduction, and achieving optimal decisions for performance, quality and manufacturability. The approach will be demonstrated in a case study. The results of this research offer an effective method to understand the effects of tolerances on performance. This method treats the tolerance sensitivity of the whole system rather than an individual link. Yet, it allows one to identify unambiguously the relative impact of each individual tolerance on the performance quality and to select a system less sensitive to the tolerances. For mechanism synthesis, it is applicable to any type of synthesis problems, including function, path, and motion generation or finite, infinitesimal and mixed positions. Its effectiveness remains unchanged regardless of the number of desired positions or the number of links. In summary, this research leads to a method which enables designers to vigorously pursue the optimal parameter design and tolerance allocation concurrently in the early stage of the design process. Thus, manufacturing cost reduction, fast product design and prototyping, and off-line quality control is achieved.