摘要 |
<p>A method of and apparatus for dynamically calibrating a machine are disclosed in which a laser interferometer is provided in addition to the machine scales for taking independent measurements of a movement of a machine part while the part is in motion. As the moving machine part reaches pre-determined distances along its movement (e.g. every inch) the readings of the interferometer and the machine scales relating to the movement of the machine part are recorded and compared. Any difference is recorded for use in mapping the machine errors. In the preferred form of the invention a reflector is mounted on the machine spindle adjacent to, or in place of, a tool or measuring probe, and its movements are measured by the interferometer. The interferometer is arranged to generate a signal as each pre-determined distance is reached and an infra-red signal is transmitted from the interferometer to a receiver on the machine spindle which is wired into the probe or tool detection circuits. This signal initiates reading of the machine scales in the same manner as the probe would normally operate. In this way not only can physical errors in the machine movement be corrected but time delays in the electrical signalling system can be allowed for.</p> |