High-Speed, Small-Deformation Catching of Soft Objects Based on Active Vision and Proximity Sensing

Abstract

In this letter, we propose a combination of sensing and control modules for catching soft objects (i.e., a marshmallow and paper balloon) at a high speed with small deformation. A paper balloon and marshmallow are deformed by a small force and they have individual differences in terms of softness. Therefore, model-based, small-deformation catching is difficult. To realize small-deformation catching, we used high-speed sensor-based (vision and proximity) control modules without a deformation model of the soft objects. A high-speed vision-based controller adjusts the positions of the fingertips of a robot to some extent. As the distance to the object decreased, the fingertip positions were accurately controlled by the high-speed, high-precision proximity-based control. Furthermore, the fingertips were stopped by a proximity-based contact detection before the object surface was deformed. Virtual damping control was effective in catching an object whose surface can be easily deformed by a small impact force or vibration of the fingertips, such as a paper balloon.

Proximity Perception in Human-Centered Robotics: A Survey on Sensing Systems and Applications

“…IV-A3). To measure distance and posture more precisely, Koyama et al [70], [71] developed a high-speed, high-precision proximity sensor, as shown in Fig. 11 (b).…”

“…A contact situation with a soft object can be detected with very low contact force. The contact detection enabled the catching of very soft objects, namely a marshmallow and a paper balloon, with negligible deformation [71].…”

Review of Robot Skin: A Potential Enabler for Safe Collaboration, Immersive Teleoperation, and Affective Interaction of Future Collaborative Robots

“…For a conducive object with an area of 100 × 70 millimeters 2 , the sensor could detect it from a distance of 120 millimeters. In addition to the above body-covered proximity skin for human safety, finger-covered proximity skin can be used for secured grasping [98], [99]. As shown in Figure 5(e), Koyama et al [100] developed a high-speed proximity sensor for the robotic fingertips to control the positions and postures of robot hand without contact before grasping, which means there is no fear of damaging the end-effector or the object.…”

Adaptive Grasping of Moving Objects through Tactile Sensing

“…In a study by Cuevas-Velasquez et al, the researchers used four structured light cameras to track the far-field motion of the object and a robotmounted stereo camera to track the near-field motion [32]. The most sophisticated object tracking setups have used specialised motion capture hardware, designed specifically to track the motion of objects moving in a 3D space [2,25,33,34]. While these systems boast the greatest accuracy and reliability, they are expensive and require a complex environment setup.…”