Human Operator Dynamics Research Articles

Human Operator Dynamics for Aural Compensatory Tracking

The effects of aural and combined aural and visual displays of tracking error on human operator dynamics were investigated using a compensatory tracking task. The aural displays indicated error magnitude with tone pitch and error polarity by either modulating the tone or by switching it between the ears. Describing functions, remnants, and rms tracking performance were measured with test conditions which were similar to those for previous studies of visual tracking performance. Human operator control characteristics measured for aural displays agree closely with those which result for visual displays. Also, operators could control equally well with either one- or two-ear displays. However, the reduction in operator time delays, expected because of the generally faster human response to aural stimuli, was not clearly evident in the results. Results also indicate that the combined aural and visual presentation of tracking error improved operator performance slightly.

On the sampling characteristics of the human operator in multi-variable systems

Past works concerning the human operator dynamics are replete with the single-loop characteristics. Multi-loop control characteristics of the human operator have been unable to be evaluated from the single-loop data due to a number factors that are unique to multi-loop systems. One of the important factors in the multi-loop control system is the scanning characteristics exhibited by the human operator.An experiment has been made to investigate the scanning rule of the human operator controlling a multi-loop system with separated displays. It has been found out that the human operator sets his permissible error region in each display and controls the system referring to the permissible error region. As a result of this experiment, a scanning model is proposed and the distribution functions of fixation time and sampling time are studied theoretically.

The Polarity Coincidence Correlation Technique- A Useful Tool in the Analysis of Human-Operator Dynamics

The paper describes a special correlation technique. It is shown that a two-state characterization of a random process leads to a simple correlation procedure, called the polarity coincidence correlation method. The utility of the method in dynamics studies of man-machine systems, its limitations, its assumptions, and, finally, the accuracy due to a finite time of observation are discussed.

A theory for optimal deterministic characterization of time-varying human operator dynamics

A deterministic theory of characterization is presented which can be used to determine the time-varying dynamics of the human operator engaged in a tracking task. With this theory it is possible to obtain a time-varying impulse response function and a time-varying transfer function which represent the action of a human operator in an open- or closed-loop control system. No special form of input is required. The characterization, that may be in either real-time or nonreal-time, is based upon an exact theory of fixed-form optimization. A strongly convergent, definitely stable iteration technique can be used to realize the optimal characterization filter. The theory takes the time variation of the impulse response or transfer function into account, so that it is unnecessary to make the assumption of slowly varying dynamics. An uncertainty or compromise exists between the error, i.e., the error between the output of the human operator and that of the optimal characterizing filter, and the degree of variability of the optimal characterizing filter. This uncertainty is fundamental, and therefore cannot be circumvented. Although the theory has been verified by extensive experimental study, emphasis here is placed upon presentation of the theory.

A literature survey of biocontrol systems

Review of the various aspects of biological control systems and their relation to feedback theory is presented in this paper. To systematize the study of biocontrol systems the material is classified into the following topics: 1) General Human Operator Dynamics; 2) Neuromuscular Systems; 3) Eye Dynamics; 4) Respiratory and Circulatory Systems; 5) Biological Process Control; 6) Central Nervous Systems and Brain. Each of the above topics is summarily discussed and each is separately documented with the pertinent literature and research activities. In the conclusion of the paper the connection between the recent theoretical work in feedback control and the problems of bio-control systems is discussed. It is hoped that with this survey a new burst of research activities on the part of control scientists in the challenging field of biocontrol systems will be materialized.

Dynamics of Human Operator Control Systems Using Tactile Feedback

Much has been learned in the past ten years about the dynamic performance of the human operator in control tasks primarily involving visual stimuli. In many human activities, however, sight is complemented or superseded by other senses. One important sense modality whose dynamic use is as yet poorly understood is touch. This paper describes an experimental technique for investigating human operator dynamics in tasks where tactile stimulus information is of primary importance; some exemplary results are presented.