Multiple-terminal hybrid graphics for control-system analysis

Abstract

Hybrid computation can be extremely efficient, not only in solving certain dynamics and control-system problems, but also in the graphical presentation and analysis of results. Analysis routines, simu lation, and animation can be interactively graphed in a time-shared mode using analog generated dis play with storage-type terminal screens. Many types of control problems amenable to graphical analysis and solution display may not require the large memory and sophistication of all-digital graphics. Hybrid-analog graphics provide an effi cient alternative, as demonstrated with two examples using root-locus and Nyquist diagram analyses. By employing the digital computer on an intermittent basis for calculation of root-locus and Nyquist data, efficient use is made of the analog in solving differential equations describing the system and in generating displays. Parallel effort between the two computers minimizes the total computational time required. Programming of analog logic allows a number of users of terminals to simultaneously select analysis, simulation, or animation options; to set parameter values, initial conditions, and display options; and to change problem configurations. This allows each user interactive graphics for system analysis on a fast, time-shared basis.