An ultrasonic collision detection system

Robots in manufacturing are increasingly being called on to do complex tasks that require intelligence beyond merely following a preprogrammed path. In robotic assembling of mechanisms, welding, machine tending and other tasks, sensing enables robots to adapt to their environments. In this research, an ultrasonic collision detection system for an industrial robot was designed, constructed and tested. Two ultrasonic transducers and ranging modules were mounted on the robot wrist to detect and prevent collisions with objects placed in the end effector's path. Experiments were conducted to determine objectto-robot distance as a function of robot speed after the robot had stopped. Two robot motions and two loads were studied. Statistical methods of stopping distance vs. robot speed are presented and will be useful in planning robot tool paths. This ultrasonic collision detection system can be used on stationary and mobile robots, automatic-guided vehicles, and other manufacturing applications.