Abstract
Flexibility of software for real-time control of machinery becomes one of the major objectives in view of ever increasing software costs. Such flexibility promotes efficiency in the development stage, but even more so, it enhances maintainability and facilitates upgrade during retooling and job changeover. A multilevel organization of software is described whereby the computational units in a particular level perform a special class of tasks and have specific privileges assigned to that level. A slot-matrix frame of the top control level along with a knowledge base provides for flexible chaining of various functions from the levels below, thus allowing substantial new features to be incorporated into the system if and when required. At the interactive level, selection alternatives for the operator are intelligently inferred and displayed through a rule base, and inputs are interpreted. The entire software is embedded in a number of processes for off-line computations, real-time control, transformations and data transfer. An example for robotic applications is elaborated.
