一种可定制参考过程模型的自动构建方法

过程模型在企事业单位中的应用日益普遍.由于企业为每个特定业务需求单独开发过程模型是复杂并且高成本的工作,因此企业通常使用参考过程模型作为过程模型开发的基础,以有效降低成本并提高开发效率和质量.由于参考模型需要领域专家大量的领域分析和抽象建模工作,如何基于领域内已有的过程模型变体自动创建出初步的参考模型以辅助领域专家的工作成为有意义的研究问题.现有的参考模型构建方法存在输出模型复杂度较高或难以全面表达领域内多样推荐实践等问题.为了创建代表性和可读性更强的参考模型,基于相似过程片段聚合技术,提出了一种支持层次化子过程结构的可定制参考过程模型的自动构建方法,全面支持可定制参考模型中基础过程、变更可选项以及约束关系的自动构建.案例研究结果表明:该方法生成的参考模型具有良好的领域代表性和模型复杂度.

Performance enhancement of IMC-PID controller design for stable and unstable second-order time delay processes

An IMC-PID controller was proposed for unstable second-order time delay system which shows the characteristics of inverse response(RHP zero). A plot of Ms versus λ was suggested to calculate the suitable tuning parameter λ, which provides a trade-off between performance and robustness. Six different forms of process models were selected from literature to show the applicability of the present method. Performance of controller was calculated by ITAE and total variation TV and compared with recently published tuning rules. Undesirable overshoot was removed by using a set-point weighting parameter. Robustness was tested by introducing a perturbation into the various model parameters and closed-loop results show that the designed controller is robust in the case of model uncertainty. The proposed method shows an overall better closed-loop response as compared to other recently reported methods.

MC环境下设计维度纵深式模块化产品族设计方法研究

从探讨定制产品生产过程的机理出发,提出了包含生产时间维、定制层次维的"定制产品山峰制造模型",提出了"设计维度纵深式模块化产品族设计方法",建立了产品系列矩阵、基型模块矩阵、基型模块n级子模块矩阵,结合数据库建立了该设计方法的设计流程,给出了相应算法,最后通过实例验证了该方法的可行性与有效性。