Preventive Maintenance for Complex Systems Under Transient State

本课题主要研究复杂系统在暂态状态下的预防性维护问题。目标是开发用于操作和表征预防性维护系统的模型和算法。具体而言，为实现既定目标，本研究力求实现以下目标：(1)以系统瞬态现象和老化过程为重点，发展表征复杂多单元系统故障和更新过程分布的技术；(2)考虑维修成本，构建基于暂态公式的更新和半再生过程分析模型；(3)以最小化维护成本为目标，利用优化技术和启发式方法探索所得超越函数的凸性；(4)制定一套成本边界指标，协助分析成本方案的合理性和敏感性；(5)通过离散事件仿真验证了模型和算法的灵敏度和耐久性。实际工业数据将用于模型的测试和验证。今天许多人造系统的特点是机械、电气和电子元件高度集成以产生一个工作系统。由于系统中单个或组件组的故障，高集成度也增加了对故障的脆弱性。一个可靠和可行的预防性维护程序，确保机器的高运行时间和更高的生产效率。提高生产力对于企业和国家的经济竞争力都是至关重要的。如果成功，作为本研究的一部分开发的工具将有助于实现有效的预防性维护计划。考虑到保持系统运行和防止灾难性故障的关键需求，这一领域的研究可以为工业世界提供很多东西。

9500289 Okogbaa This research project focuses on the problem of preventive maintenance for complex systems under transient state. The goal is to develop models and algorithms useful for operating and characterizing a preventive maintenance system. In particular, the following objectives are pursued to realize the set goal: (1) develop techniques for characterizing failures and renewal process distributions for complex multi-unit systems with emphasis on systems transient phenomenon and the aging process; (2) construct analytical models based on transient formulation using renewal and semi-regenerative processes with maintenance cost consideration; (3) explore the convexity of the resulting transcendental functions using optimization techniques and heuristics with the aim of minimizing maintenance costs; (4) develop a set of cost boundary indices to assist in analyzing the reasonableness and sensitivity of the cost options; and (5) test and verify the sensitivity and endurance of the models and the algorithms using discrete event simulation. Actual industrial data will be used in the testing and validation of the models. Many man-made systems today are characterized by mechanical, electrical, and electronic components that are highly integrated to produce a working system. With high integration also comes increased vulnerability to failure due to the malfunctioning of individual or groups of components in the system. A reliable and workable preventive maintenance program ensures a high run time for machines and a more productive system. Increased productivity is essential for economic competitiveness both for a company and to a nation. If successful, the tools developed as part of this research will contribute to the realization of effective preventive maintenance programs. Given the critical need to keep systems running and prevent catastrophic failures, research in this area has much to offer to the industrial world.