Abstract

Humans respond very quickly and effectively to haptic information during the manual control of machines. If we better understood the characteristics of physical human- machine interaction, we could design products that intelligently take advantage of this bi-directional communication method. In this thesis, I investigate the particular situation of haptically communicating with the user of an exercise machine to assist the user in maintaining a consistent workout intensity in the presence of a mental distraction.

I modified a commercial stair climber to communicate information to its user both kinesthetically and tactilely. I developed and experimentally tested five haptic communications that alert or assist a user if workout intensity begins to fall. Results showed that haptic communications could modify subject workout intensity. Subjects preferred a cue that 'tapped' on the pedals if the subject was going too slow. This cue was one of the most noticeable cues and had no detrimental effect on the mental task. One of the least preferred cues was one that tapped continuously, serving as a haptic metronome. Although this cue assisted subjects in maintaining workout intensity, it was reported as confusing and distracting by subjects and was the only cue to negatively affect performance on the mental task. However, I believe that other forms of continuous cues may have potential and should be further investigated. Results also verified the claim by others that vibration often goes undetected and is more annoying than other sensations.