| 摘要 |
A machine tool coordinate measuring machine (CMM). The CMM includes a frame having one or more members and a table on which the workpiece is secured. The members and table are movable relative to each other, typically along 3 axes. A probe assembly having a probe configured to contact a desired surface of the workpiece is mounted on one member of the machine tool frame and one or more scales are mounted on the machine tool frame to provide positional data identifying a relative position between various pairs of either the members and/or table along each axis. A controller controlls the probe assembly, reads the scales to obtain the positional data. The controller includes a multidimensional temperature compensation unit that dynamically determines temperature characteristics of the machine tool frame based on information provided by temperature sensors mounted on the frame and compensates the positional data accordingly. A volumetric compensation unit mathematically models and measures repeatable geometric errors of the machine tool frame and compensates the positional data accordingly. Thus, the controller generates compensated positional data, which is stored and subsequently used by a conventional measurement planning, analysis and reporting unit. This unit is responsive to the operator, generating commands for use by the controller and analyzing the compensated positional data to determine the location of points along a surface of the workpiece. The machine tool CMM operates with high accuracy and repeatability in workshop environments and, as such, can be integrated into the workpiece manufacturing cycle to monitor in real time the quality of the process and to identify when corrective feed-back actions that prevent the production of defective components are required.
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