patent number 4715773
An apparatus and method for translating an object held by at least two fingers of a robot hand to a predetermined position relative to a fixed point of the robot hand is disclosed. The apparatus comprises a linear potentiometer for sensing the position of each finger relative to the fixed point on the robot hand. A microcomputer identifies the finger at the greater distance from the predetermined position as the position-controlled finger, and identifies the other finger as the force-controlled finger. Pneumatic cylinders and valves impart movement to each finger. A pneumatic servovalve controls movement of the position-controlled finger according to the position of the position-controlled finger relative to the fixed point of the robot hand. In an alternative embodiment, the movement of the position-controlled finger is controlled according to both the position of the position-controlled finger and the position of the force-controlled finger. A pair of strain gages senses the force between the force-controlled finger and the object. Another pneumatic servovalve controls movement of the force-controlled finger according to the force sensed between the force-controlled finger and the object.
Clemson University (Clemson, SC)
318/568.21, 414/800, 700/245, 700/260, 901/9, 901/34