A High-Resolution Imaging Touch Sensor

A dexterous robot manipulator must be able to feel what it is doing. The mechanical hand of the future will be able to roll a screw between its fingers and sense, by touch, which end is which. This paper describes a step toward such a manipulator, an imaging tactile sensor with hundreds of pressure sensors in a space the size of a fingertip. The sensor was designed as part of a tendon-actuated mechan ical finger, similar in size and range of motion to a human index finger (Hillis 1981). As a demonstration, the device was programmed to distinguish among several commonly used fastening devices—nuts, bolts, flat washers, lock washers, dowel pins, cotter pins, and set screws—by touching them with the finger and analyzing the tactile image. This paper describes how the tactile sensor array was constructed and how it works. The simple pattern- recognition techniques used in the demonstration program are also outlined. The final section notes some promising directions for future research.