The performance of a deformable-membrane tactile sensor: basic results on geometrically-defined tasks

Abstract

The limitations of rigid fingertips in the precise and algorithmic study of manipulation have been discussed in many works, some dating back more than a decade. Despite that fact, much of the work in dexterous manipulation has continued to use the "point-contact" model for finger-object interactions. In fact, most of the exsisting tactile sensing technologies are not adaptable to deformable fingertips. In this work we report on experimental results obtained with a deformable tactile sensor whose properties are well-suited to manipulation. The results presented here show that the sensor described provides a rich set of tactile data.

Model-Free Precise in-Hand Manipulation with a 3D-Printed Tactile Gripper

“…It differs from previous optical tactile sensors by adopting and tracking biomimetic pins on its inside surface. The compliance of the TacTip is an intrinsic part of its transduction mechanism and renders it ideal to investigate manipulation, as soft sensors have been demonstrated to be more effective than rigid sensors at grasping [22], as well as accurately detecting phase changes in manipulation tasks while maintaining grip [23], [24]. Although studies using model-based approaches to soft finger sensing have been performed [25], we opted for a non-model based method based on running a training phase to construct a likelihood model, following other work on using biomimetic active touch to perceive and explore objects [26], [27].…”

Localization and manipulation of small parts using GelSight tactile sensing

“…Another important area of related work has to do with other tactile sensors that measure deformation in a deformable membrane. For example, Hristu, Ferrier, and Brockett proposed a deformable membrane tactile sensor that operates by tracking dots printed on a deformable membrane and reconstructing the contact geometry using a finite elements approach [16]. Wettels, Smith, Santos, and Loeb, developed a sensor that measured pressure in a weakly conductive fluid fingertip at a small set of locations [17].…”

Determining object geometry with compliance and simple sensors

“…However, they tend to be expensive and complicated, and popular commercially-available systems for robotic hands can cost tens of thousands of dollars. Deformable Fingertips filled with fluid have also been developed [19], but pose manufacturing challenges. Intrinsic force-torque sensors can be used to measure contact forces and locations over the full fingertip [7], but because they are fragile and expensive, they are better suited to manipulation than active exploration.…”