Visionless Tele-Exploration of 3D Moving Objects

This paper presents methods for improved teleoperation in dynamic environments in which the objects to be manipulated are moving, but vision may not meet size, biocompatibility, or maneuverability requirements. In such situations, the object could be tracked through non-geometric means, such as heat, radioactivity, or other markers. In order to safely explore a region, we use an optical time-of-flight pretouch sensor to detect (and range) target objects prior to contact. Information from these sensors is presented to the user via haptic virtual fixtures. This combination of techniques allows the teleoperator to “feel” the object without an actual contact event between the robot and the target object. Thus it provides the perceptual benefits of touch interaction to the operator, without incurring the negative consequences of the robot contacting unknown geometrical structures; premature contact can lead to damage or unwanted displacement of the target. The authors propose that as the geometry of the scene transitions from completely unknown to partially explored, haptic virtual fixtures can both prevent collisions and guide the user towards areas of interest, thus improving exploration speed. Experimental results show that for situations that are not amenable to vision, haptically-presented pretouch sensor information allows operators to more effectively explore moving objects.