Abstract: This paper introduces an economical optical system which can be used to measure the coordinates and pose of an object in Euclidean space. The main part of this system is a conical sensor. When a laser beam sweeps the sensor, the plane of the scanning beam intersects the conical body. The sensor can be mounted on the manipulator end-effecter, and the sensor coordinate system can be used as the coordinate system of the manipulator tip. Three laser beams at three fixed places sweep the sensor, and the coordinates and pose of the manipulator tip can be accurately measured.