Designing Programming Languages for Manufacturing Cells

A manufacturing cell is a complex collection of machines and electronics which must be intelligently supervised. It should be flexible enough to readily adapt to different part styles and robust enough to operate without human assistance for reasonable periods of time. A programming language with a correct choice of language properties can make meeting these demands and others like them a manageable programming task. A rule based language in conjunction with a set of grammatical constraints supervises a cell which manufactures turbine blade pre-forms. The non-procedural nature of the language provides considerable flexibility in the operation of the cell. The rules are executed in no particular sequence, but rather as the cell is ready for them. Unfortunately, the non-procedural approach allows for unplanned interactions between rules. Most of these interactions can be avoided by defining which rules can operate concurrently. The language is logically linked to the pre-form cell through a simple database management system. The database system maintains a model of the cell used by the language interpreter to decide which rules to execute. This database system also protects the cell programmer from the low level programming details (e.g., communication protocols).