EFFECT OF EXPONENTIAL TYPE CONTROL LAGS ON THE SPEED AND ACCURACY OF POSITIONING A VISUAL INDICATOR

摘要

There is inherent in many controller systems a lag between the time that an operator positions his control and the time that the corresponding effect is achieved. Very frequently this lag approximates an exponential. Function. The present investigation was conducted to determine what effect, if any, such controller system lags have on the human operator's ability to position a visual indicator rapidly and accurately.nTwenty subjects were used in this experiment. Each subject repeatedly set a pointer to a fixed reference position by means of a rotatable control knob. Exponential lags of 0, 40, 120, 360 and 1000 milliseconds were introduced between the control and display. On the basis of the experi-mental findings it is concluded that any amount of exponential lag reduces the speed and accuracy of setting the pointer. The longer the lag the more pronounced is the effect. However, it appears that the human operator does modify his behavior somewhat so as to compensate to a. limited extent for an increased lag