Realtime system control by means of path expressions

A high-level, algebraic programming method for the online control of actions in a real-time, parallel processing environment is described. The method is based on the interaction of path expressions. On the basis of a set of path expressions, evocation of actions can be controlled in real-time in a fully automated way. It is shown how intelligent system behavior can be obtained by a combination of rules given as path expressions. Each of these rules specifies some partial behavior to which the system must comply. The control system operates as a rule-based action planning system that works online in an asynchronous environment. The development of the prototype system PBOS (Path Based Operating System) has demonstrated that path expression specification naturally integrates with a real-time, multitasking control system