Human finger inspired grasping structure using tactile sensing array with single type optoelectronic sensor

Abstract

In this paper, we address how to utilise one type of sensor in a tactile sensing array, such as a robot fingertip that grasps and manipulates objects. The tactile sensing array measures contact force by using optoelectronic sensors and has two types of sensor mechanical flexures, each with a different stiffness and contact force resolutions. The sensing principle is to measure deformations in the form of distance between the flexure structure and the sensing element using light intensity in two different sensing ranges of the optoelectronic sensor, hence estimate the force components. This sensing principle and novel flexure structure recognises contact and allows the robot fingertips to stably grasp an object, thus mimicking the action of grasping by human fingers. This low cost bespoke design has a high sensing resolution, low noise and a robust structure. Its simple fabrication and miniaturisation makes it adaptable to any type of shape within a mechanical structure. We present a preliminary study including the design and experiments for sensing performance and the characteristic curve of an optoelectronic sensor on the tactile sensing array.