Visuo-haptic transmission of contact information improve operation of Active Scope Camera

Disaster response robots for searching in a narrow area have limited space to mount tactile sensors, but the operators require sensory feedback to recognize contact situations with the surrounding environment. This study proposes a new approach to transmitting contact information of a remote-operated snake-like robot called Active Scope Camera (ASC) to the operator using simple configurations for the sensing and display methods. For the sensing side, we develop a contact estimation method with a limited number of tactile sensors. We establish the method to localize the contact position and the magnitude by sensing multiple propagated vibrations based on experiments and formulations. Preliminary experiments show that the developed method estimates a collision angle with high probability (93.8% at the worst condition) at several collisional situations. For the display side, we combine visual and vibrotactile feedback to provide the operator both directional and temporal cues to perceive contact events. The proposed visualization method uses colored bars, peripherally superposed on the video image, to show the estimated contact location and magnitude. A single DoF vibrotactile feedback is used for a joystick interface to control the head movement of the ASC. The effect of vibrotactile feedback on the response time to contact events is evaluated. Finally, we investigate the performance of the operation by identifying the contact behavior at simulated scenarios. Experimental results show that collision times per operation time is decreased by the developed feedback system compared with a simple video-based operation.