A hierarchical system structure for coordinated control of industrial manipulators

This paper describes a framework for the intelligent control of industrial manipulators. The structure is designed to allow a robotic system to take full advantage of the improved sensing capabilities and more powerful languages that are now becoming available. The framework consists of two layers of hierarchy for the coordinated control of multi-jointed industrial manipulators. The low level control mechanism, responsible for servoing each joint, is adaptive to both manipulator dynamics and payload changes. The individual low-level joint controllers are integrated and coordinated by the high level control structure. Together, the two levels provide a versatile basis for manipulator control. This basis forms a complete structure, and is suited for interfacing with yet higher level intelligent systems such as task planners, high level languages, and environment sensitive path planners.