Generation and Evaluation of Machining Alternatives

在机械零件设计过程中所做的决策会对产品的成本、质量和交货期产生重大影响。因此，重要的是评估设计的可加工性，提供反馈，以便设计者可以更改设计以提高其可加工性。就机械加工而言，零件通常被认为是可加工特征的集合。然而，对于同一零件，通常可以有几种不同的解释，作为不同的可加工特征集合。每种解释以不同的顺序对应于一组不同的加工操作，具有不同的可加工性。为了确定零件的可加工性，应生成所有这些备选方案并对其可加工性进行评估。这项研究将开发出自动完成这一任务的方法。为了生成可选的特征解释，研究人员将使用代数方法，其中新的解释将通过对旧解释的代数运算来产生。为了评估每个特征的可加工性，研究人员将考虑特征几何形状、公差要求、表面光洁度要求以及加工能力的统计变化。这种分析提供的信息可用于几种方式：(1)向制造工程师提供有关零件加工的替代方法的信息。根据机床的可用性，这些信息在开发工艺规划替代方案时可能很有用。(2)向设计人员提供反馈，以确定加工过程中可能出现的问题。通过将可达到的最佳公差与设计者的公差要求进行比较，研究人员应该能够建议对设计进行微小的更改，从而显著改善可加工性。

Decisions made during the design of a machined part can significantly affect the product's cost, quality, and lead time. Thus, it is important to evaluate the machinability of the design, providing feedback so that the designer can change the design to improve its machinability. For machining purposes, a part is often considered to be a collection of machinable features. However, often there can be several different interpretations of the same part as different collections of machinable features. Each interpretation corresponds to a different set of machining operations, in a different order, with different machinability. To determine the machinability of the part, all of these alternatives should be generated and their machinability evaluated. This research will develop ways to do this automatically. For generating the alternative feature interpretations, the investigator's will use an algebraic approach, in which new interpretations will be produced via algebraic operations on old interpretations. For evaluating the machinability of each feature, the researchers will take into account the feature geometry, tolerance requirements, surface finish requirements, and statistical variations in the process capabilities. The information provided by such an analysis can be used in several ways: (1) To provide information to the manufacturing engineer about alternative ways in which the part might be machined. This information can be useful in developing process planning alternatives depending on machine tool availability. (2) To provide feedback to the designer identifying problems that may arise with the machining. By comparing the best achievable tolerances with the designer's tolerance requirements, investigator's should be able to suggest small changes in the design that will significantly improve the machinability.