Integrated process control and condition-based maintenance scheduler for distributed manufacturing control systems

Competitive enterprises resort to decentralization and distributed structures to manage and control complexity. Integrated decision-making within these autonomous controllers can enhance the performance of these systems. In this paper, it is hypothesized that a significant improvement in performance can be realized by taking process control decisions in conjunction with condition monitoring and machine maintenance decisions in a distributed environment. An architecture is proposed for unifying process control and condition-based maintenance scheduling. Sensory information indicative of the current condition of the machine is also provided to autonomous controllers to enable estimation of the remaining useful lifetime of the machine. Estimates of the remaining lifetime of the machine and the scheduled maintenance time are than used to adjust the set points for the operating parameters and modify the maintenance schedules for the maintenance crew, respectively. The proposed architecture is presented and exemplified using a case study of laser-based free-forming process. The results indicate that the architecture can adjust the operating parameters and develop new maintenance schedules based on the changes of the machine condition.