State Models for Jobs and Job Supervisors

摘要

Intelligent control of discrete parts manufacturing jobs and machinery requiresstate models for the jobs and the controllers. Different approaches to control have yielded different state models. While a dominant model is yet to emerge, the advantages and shortcomings of the existing models suggest some design principles for future efforts; most importantly, the demarcations between the shop level of control and the workcell level, and between the job, the lot, the controller, and the machine, should be well-defined.