Author: Lin, XiPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Tactile perception subserves the impressive dexterity found in humans but also found in their robotic counterparts. Recently, a new wave of tactile sensors relying on off-the-shelf cameras, provide a dense tactile image of the contact. However, by the way these sensors operate, the link between the mechanics of the skin and the tactile images is not evident. In this thesis, we present a novel camera-based tactile sensor, named ChromaTouch, which captures physically-driven dense images of the three-dimensional interaction that happens at the interface between the artificial skin and the touched object. The sensor measures the strain field induced by the contact, by imaging the pattern and color change of two overlapping markers array, one translucent and yellow and the other opaque and magenta. The motif seen by the camera is a bijective function of the relative motion of the markers allowing a reconstruction of the stress and strain field at the interface. The sensor, boasting up to 441 sensing elements, shows high robustness to external luminosity and camera resolution, and it is able to estimate the local coefficient of friction of the contact surface with one simple press. A hemispherical version extended the results to arbitrary shapes and is able to estimate the local curvature via a simple press using Hertz contact theory. Sensing the dense 3d deformation field at the contact opens the doors to a comprehensive, physically-based measurement of the interaction. Improved artificial perception of the object and of the interaction can inform robotic exploration, dexterous grasping and manipulation.
