Effort involved in single- and two-axis manual control systems

A theoretical and experimental program was conducted to study human response characteristics in a variety of single- and dual-axis control situations. The object was to build and support a human control effort model. The aspect of human controller's effort is indispensable for a complete description and prediction of human operator behavior and its impact on mission success. The model is formulated in the framework of optimal control theory. The control effort model results are compared with subjective ratings reflecting the effort exerted in performing a variety of single-axis and dual—axis tracking tasks. Eight single-axis control configurations were examined in order to include a wide range of human response characteristics and task difficulty. Four single—axis tasks were combined, yielding four dual-axis configurations to extend the control effort model to multivariable control situations. Especially the latter part of the program is exploratory. The excellent agreement between computed and rated control effort is very encouraging, although the multivariable control effort model needs further development and validation by means of more experimental data.