Method of and apparatus for reducing vibrations on probes carried by coordinate measuring machines
AssigneeRenishaw PLC
InventorKenneth C-H Nai
Life of this patent
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Abstract
A coordinate measuring machine (CMM) carries a probe and is controlled by a controller to drive the probe to take measurements on a workpiece. In order to reduce the effects of acceleration-induced deflections of the probe on the measurements made by the machine, accelerometers are provided to measure the accelerations of the probe and to produce signals indicative thereof. The acceleration signals (45) are passed to the controller (FIG. 2) where they are integrated (46) and filtered (48) before being passed as velocity signals (49) to a summing junction (50) from which they are fed to a velocity feedback control loop (34,35,36,37) which reduces any changes in the velocity (and hence deflection) of the probe due to the accelerations.
Claims5
A method of reducing measurement errors made by a machine using a probe carried by the machine comprises the steps of:
- deriving acceleration signals indicative of accelerations of moving parts of the machine,
- deriving from the acceleration signals, velocity signals indicative of the change in velocity of the moving part caused by the accelerations, and
- using the velocity signals in a velocity feedback control loop to provide correction signals to the machine to reduce the effects of acceleration-induced deflections of machine parts on the measurements made by the machine using the probe.
Dependencies are inferred from the claim text.