MAPPING STRATEGIES OF DISTANCE INFORMATION BASED ON CONTINUOUS VIBROTACTILE AMPLITUDE AND FREQUENCY VARIATION - THESIS JOHANNES F. RUESCHEN

Our study investigates how different mapping strategies of distance information affect performance in an object exploration task with a teleoperated virtual robot. The task was to find an object inside a backpack using a simulated robotic gripper. A virtual proximity sensor tracked the distance between the tip of the gripper and the object. The distance was conveyed as a vibration pattern on the users index finger. This is the only information that was received to guide the user towards the object. The goal was to locate the hidden object by moving the tip of the gripper as quickly and as closely towards the object as possible without touching it. We implemented three different mapping strategies that utilized continuous frequency and amplitude variations of sinusoidal vibrations to encode distance. The present study provides empirical evidence that the mapping strategy can affect accuracy when approaching an object. We found that linear feedback sensations help to sense the rate of approach. Non- linear feedback perception can provide cues that enable more accurate approximation of the absolute distance. We found that experienced participants could selectively attend to and integrate frequency and intensity cues when both modalities are changed simultaneously. Inexperienced participants were not able to make this distinction and found it difficult to interpret such a signal. They preferred one-dimensional changes.