Clemson University

Joey K Parker

Frank W Paul

Proximity sensors are used to sense impending contact, i.e., a point of close approach, between a finger of a robot hand and an object. Each finger is equipped with force sensors so that finger touch force with the object can be measured and controlled. The hand is controlled by a dedicated microprocessor, which communicates with a robot arm controller through 8 digital input/output lines. A novel 'bi-modal' control system uses information from the proximity sensors to control both solenoid (on/off) valves and a proportional servovalve which are alternatively switched into an operative mode in a pneumatic circuit which powers the pneumatic actuators of the hand. This control design achieves the two goals of rapid object acquisition and low interaction forces. Each finger of the hand is capable of implementing an acquisition strategy in which mislocated objects can be acquired.

Method and apparatus for controlling impact force during rapid robotic

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.

Growing community of inventors

Tuscaloosa, AL, United States of America

Joey K Parker