Real time machine tool error correction using global differential wet modeling
AssigneeKam C. Lau
InventorsKam C. Lau, Quanhe Ma, Herbert Lau
Life of this patent
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Abstract
A machine tool is controlled through a process incorporating the steps of (1) measuring geometric and thermal errors with accurate instruments, (2) creating a global differential wet model of machine tool position, and (3) using this model to control real time compensation of machine tool operation. A controller modifies encoder-type position feedback signals used by the machine to compensate for geometric and thermal errors in the manner dictated by the global differential wet model.
Claims14
A method of compensating for positioning errors in a device with a precision positioning control, comprising the steps of:
- (1) measuring positioning errors of the device relative to changes in temperature at a plurality of changes in temperature;
- (2) creating a global differential wet model of positioning errors from the measured positioning errors, and
- (3) measuring relative temperature changes in real time and using said model to generate real time position compensation signals to modify the operation of the device.
A system for compensating for positioning errors in a device with a precision positioning control, comprising:
- a plurality of thermal sensors located in various positions on the device for determining temperature changes at the various positions;
- a plurality of positioning sensors located on the device for determining device position;
- means for collecting temperature change and position data during operation of the device to create a global differential wet model;
- and
- a controller for storing the global differential wet model, wherein the controller generates real time position compensation signals based on the global differential wet model to modify the operation of the device precision positioning control.
Dependencies are inferred from the claim text.