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Spatial coordinate measurement systems such as theodolites, laser trackers and total stations have wide application in
manufacturing and certification processes. The traditional operation of theodolites is manual and time-consuming which
does not meet the need of online industrial measurement, also laser trackers and total stations need reflective targets
which can not realize noncontact and automatic measurement. A new automatic guided laser theodolite system is
presented to achieve automatic and noncontact measurement with high precision and efficiency which is comprised of
two sub-systems: the basic measurement system and the control and guidance system. The former system is formed by
two laser motorized theodolites to accomplish the fundamental measurement tasks while the latter one consists of a
camera and vision system unit mounted on a mechanical displacement unit to provide azimuth information of the
measured points. The mechanical displacement unit can rotate horizontally and vertically to direct the camera to the
desired orientation so that the camera can scan every measured point in the measuring field, then the azimuth of the
corresponding point is calculated for the laser motorized theodolites to move accordingly to aim at it. In this paper the
whole system composition and measuring principle are analyzed, and then the emphasis is laid on the guidance
methodology for the laser points from the theodolites to move towards the measured points. The guidance process is
implemented based on the coordinate transformation between the basic measurement system and the control and
guidance system. With the view field angle of the vision system unit and the world coordinate of the control and
guidance system through coordinate transformation, the azimuth information of the measurement area that the camera
points at can be attained. The momentary horizontal and vertical changes of the mechanical displacement movement are
also considered and calculated to provide real time azimuth information of the pointed measurement area by which the
motorized theodolite will move accordingly. This methodology realizes the predetermined location of the laser points
which is within the camera-pointed scope so that it accelerates the measuring process and implements the approximate
guidance instead of manual operations. The simulation results show that the proposed method of automatic guidance is
effective and feasible which provides good tracking performance of the predetermined location of laser points.
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