Optimizing the Touch Tablet: The Effects of Lead-Lag Compensation and Tablet Size

摘要

The display control (DC) gain of a touch tablet strongly affects human performance with the tablet. The primary objectives of this research were to develop and optimize a variable D/C gain that improves human performance with touch tablets. This variable gain moderates the speed-accuracy tradeoff problem associated with conventional D/C gains. An additional objective of this research was to determine the effect of tablet size on human performance. Display control (D/C) gain is defined as the amount of movement which occurs on the display in response to a unit amount of movement of the control. With conventional D/C gains, there is a tradeoff between low D/C gain which enables time positioning, but results in very slow cursor movement, and high D/C gain which produces quick cursor movement but results in poor fine positioning ability. A lead-lag compensator was developed to ameliorate this tradeoff. This compensator combines a pure position gain component with a gain component proportional to the velocity of fire control input. The results indicate that the lead-lag compensator increased target acquisition rate relative to a conventional D/C gain system. Error rates were low with both systems, but were greater with lead-lag compensation than in an uncompensated system. Tablet size did not appear to affect performance. Keywords: User computer interface, Input devices, Human performance. (kr)