A Hierarchical Concept for Man-Machine Communication

Abstract

The problem of man controlling or programming a machine may be considered as a hierarchy of control functions, with each level of control calling up ordered sequences of operations at the next lower level, using appropriate sensory feedback for each level. Man may enter the control hierarchy at any level for direct control or for programming an automatic system for later playback. The computer carries out lower level control functions, thereby augmenting man's control capabilities. The Cerebellar Model Articulation Controller (CMAC) is a computer based control system in which high–level task–oriented commands can be broken down into a series of elemental motor actuator signals. CMAC is a general purpose adaptive control concept which can be arranged in a hierarchical structure, such as that described above, so as to facilitate the man–machine communication problem. For example, CMAC can solve the coordinate transformation problem so that commands can be given in terms of desired end point trajectories. Furthermore, CMAC can handle many feedback variables such as measurements of misalignment of parts, variable mass loading, irregularities in materials, and constraints imposed by an external environment. Concepts of man–machine communication under consideration by the NBS Automation Technology Porgram are presented with particular emphasis on the CMAC control concept.