Position measurement encoder and method of operation
AssigneeRenishaw PLC
InventorAndrew Paul Gribble
Life of this patent
Estimating the term…
Abstract
A method of operating a position encoder apparatus, including a scale having features defining position information and a readhead for reading the scale. The method includes: calculating extrapolated position information from at least one previous reading of the scale; comparing an extrapolated position with a position calculated from a reading of the scale to determine any discrepancy between them; using the extrapolated position information whether or not there is a discrepancy; and maintaining a record of any discrepancies.
Claims15
A method of operating a position encoder apparatus, comprising a scale having features defining position information and a readhead for reading the scale, the method comprising in any suitable order:
- calculating extrapolated position information from at least one previous reading of the scale;
- comparing an extrapolated position with a position calculated from a reading of the scale to determine any discrepancy between them;
- using the extrapolated position information whether or not there is a discrepancy;
- and
- maintaining a record of any discrepancy.
A method as claimed in further comprising performing an error routine in the event of discrepancies indicative of a failure of the extrapolated position.
A position encoder apparatus, comprising a scale having features defining position information and a readhead for reading the scale, in which the apparatus is configured to:
- calculate extrapolated position information from at least one previous reading of the scale;
- compare an extrapolated position with a position calculated from a reading of the scale to determine any discrepancy between them;
- use the extrapolated position whether or not there is a discrepancy;
- and maintain a record of any discrepancies.
Dependencies are inferred from the claim text.