Robot Safety Position Sensing
Original Publication Date: 1985-Jun-01
Included in the Prior Art Database: 2005-Feb-18
Positive sensing of a robot arm in a known safe position allows human access to a robot work area with robot power on. The positional sensing is either by detection of reflected light from the robot arm or by mechanical closure of a switch by the arm, when in the safe position. If the robot arm moves away from the safe position, the light beam detector or the mechanical switch causes power to be removed to stop the robot movement. Normally, safety covers, a light curtain, or pressure sensors are arranged to keep operators out of a robot's work area, and the triggering of such a device will remove the power. To get into the work enclosure while power is on, it is necessary to disable the normal safety device, thus leaving the operator exposed to sudden dangerous movement of the robot.