Electric field imaging pretouch for robotic graspers

This paper proposes the use of electric field sensors to implement "pretouch" for robotic grasping. Weakly electric fish use this perceptual channel, but it has not received much attention in robotics. This paper describes a series of manipulators each of which incorporates electric field sensors in a different fashion. In each case, the paper presents techniques for using the sensors, and experimental data collected. First, a simple dynamic-object avoidance technique is presented. Next, a 1-D alignment task for grasping is described. Then linear and rotary electrode scanning techniques are presented. It is shown that these techniques can distinguish a small object at close range from a large object farther away, a capability that may be important for grasping.