| 摘要 |
<p>A laser based coordinate measuring device (100) comprises a distance meter (103) that measures distance based at least in part on the speed of light; and a structure (190) that is rotatable by a first angle (270) and a second angle about two substantially orthogonal axes, the structure (190) launching a beam (361) from the distance meter (103). The device further includes a first encoder (91) for measuring the first angle (270) and a second encoder (90) for measuring the second angle.. A retroreflector target (185) is disposed remote from the rotatable structure (190). A locator camera (230), which comprises a second optical system (230), a photosensitive array (1404), and a plurality of light sources (1401), is disposed on the rotatable structure (190) for determining an approximate location of the target (185). The second optical system comprises a lens (1402). The plurality of light sources (1401) emits a cone of light (1440) for illuminating the retroreflector target (185). The arrangement is such that a first ray of light (1550, 1540) emitted by one of the plurality of light sources (1403) travels to the retroreflector target (185) in a straight line, a second ray of light reflected by the retroreflector target (1541, 1552) travels to the lens (1402) in a straight line and the second optical system (230) forms a pattern of light (1563, 1593) on the photosensitive array (1404). An electronics system (140) analyzes the pattern of light (1563, 1593) on the photosensitive array (1404) to determine the approximate angular direction to the retroreflector target. An actuator system (80, 81) orients the rotatable structure (190) in accordance with the location determined by the locator camera (230).</p> |
