Fingertip Proximity Sensor with Realtime Visual-based Calibration

Proximity and distance estimation sensors are
broadly used in robotic hands to enhance the quality of
grasping during grasp planning, grasp correction and in-hand
manipulation. This paper presents a fiber optical proximity
sensor that is integrated with a tactile sensing fingertip of
a robotic hand of a mobile robot. The distance estimation
of proximity sensors are typically influenced by the reflective
properties of an object, such as color or surface roughness.
With the approach proposed in this paper, the accuracy of the
proximity sensor is enhanced using the information collected
by the vision system of the robot. A camera is employed to
obtain RGB values of the object to be grasped. Further on, the
data obtained from the camera is used to obtain the correct
calibration for the proximity sensor. Based on the experimental
evidence, it is shown that our approach can be effectively used
to reduce the distance estimation error.