A prototype position and orientation sensor (POSE) has been found to measure position and orientation of a robot end effector with a linear accuracy of 10-3 inches and a rotational accuracy of 0.5 milliradians, respectively. In this Small Business Innovation Research (SBIR) program Phase II project further research focuses on (1) measurement and correction of backlash in robot joints and (2) automatic recali-bration of the robot to fixtures in its work space. The sensor has (1) a hollowed-out-cube base fixture with two collimated light beam projectors and a light-sensitive semiconductor device on each of three faces, (2) a light reflective fixture mounted on the robot hand, and (3) a computer for date processing. The POSE technology has potential for higher manufacturing productivity through increased precision in robotic manipulation and decreased time to "teach" and "reteach" robot tasks.