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US 12,146,773 B2Granted
Position encoder with fusion of different sensor types
AssigneeNovanta Corporation
InventorsDaniel J. Holmes, Paul A. Remillard, Deepak Surendran
Life of this patent
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Abstract
An opto-magnetic rotary position encoder includes a polarization optical encoder and a magnetic encoder, both configured for on-axis placement and operation with respect to a rotational axis of a rotating component. A polarization sensor digital control block and a magnetic sensor digital control block are configured and operative to combine polarizer channel position data and magnetic channel position data in a manner providing for one or more of (1) redundancy, (2) calibration, (3) monitoring performance of one channel in relation to the other channel, or (4) compensation or correction of one channel based on the other channel.
Claims19
An opto-magnetic rotary position encoder for sensing rotational position of a rotating component, comprising:
- a polarization-based optical encoder configured for on-axis placement and operation with respect to a rotational axis of the rotating component, including (1) a polarizer configured for mounting for rotation with the rotating component, and (2) polarization source/sensing components configured for mounting in proximity to the polarizer to provide a source light beam to the polarizer and to detect a polarized return light beam therefrom;
- a magnetic encoder configured for on-axis placement and operation with respect to the rotational axis of the rotating component, including (1) a magnet configured for mounting for rotation with the rotating component, and (2) magnetic sensing components configured for mounting in proximity to the magnet to detect a magnetic field from the magnet;
- and
- control circuitry configured and operative to generate polarizer channel position data from the detected polarized return light beam and magnetic channel position data from the detected magnetic field,
- and further including a magnetic sensor channel compensation unit having a comparison block for determining magnetic channel error, and a memory structure used as a lookup table, and wherein the control circuitry is configured and operative, during a system calibration mode of operation, to store polarization angle data into the lookup table at locations addressed by uncorrected magnetic angle data, and during normal operation to use the uncorrected magnetic angle data as an address to the lookup table which produces reference angle data that was stored during calibration mode.
2 more elements
An opto-magnetic rotary position encoder for sensing rotational position of a rotating component, comprising:
- a polarization-based optical encoder configured for on-axis placement and operation with respect to a rotational axis of the rotating component, including (1) a polarizer configured for mounting for rotation with the rotating component, and (2) polarization source/sensing components configured for mounting in proximity to the polarizer to provide a source light beam to the polarizer and to detect a polarized return light beam therefrom;
- a magnetic encoder configured for on-axis placement and operation with respect to the rotational axis of the rotating component, including (1) a magnet configured for mounting for rotation with the rotating component, and (2) magnetic sensing components configured for mounting in proximity to the magnet to detect a magnetic field from the magnet;
- and
- control circuitry configured and operative to generate polarizer channel position data from the detected polarized return light beam and magnetic channel position data from the detected magnetic field,
- wherein the control circuitry implements self-monitoring circuitry having (1) respective Lissajous correction blocks for the polarization-based optical encoder and the magnetic encoder, (2) a correction matrix, and (3) an error monitor receiving an output from a comparator that compares the polarizer channel position data and magnetic channel position data, and wherein uncorrected magnetic angle data is corrected by the correction matrix to generate a corrected value that matches the polarization angle data value.
2 more elements
An opto-magnetic rotary position encoder for sensing rotational position of a rotating component, comprising:
- a polarization-based optical encoder configured for on-axis placement and operation with respect to a rotational axis of the rotating component, including (1) a polarizer configured for mounting for rotation with the rotating component, and (2) polarization source/sensing components configured for mounting in proximity to the polarizer to provide a source light beam to the polarizer and to detect a polarized return light beam therefrom;
- a magnetic encoder configured for on-axis placement and operation with respect to the rotational axis of the rotating component, including (1) a magnet configured for mounting for rotation with the rotating component, and (2) magnetic sensing components configured for mounting in proximity to the magnet to detect a magnetic field from the magnet;
- and
- control circuitry configured and operative to generate polarizer channel position data from the detected polarized return light beam and magnetic channel position data from the detected magnetic field,
- wherein the polarization source/sensing components and the magnetic sensing components are mounted to an interface substrate, the polarization source/sensing components being mounted to a first side of the interface substrate facing the polarizer and receiving the polarized return light beam, the magnetic sensor components being mounted to a second side of the interface substrate facing away from the polarizer.
2 more elements
Dependencies are inferred from the claim text.