Calibration and linearization of position sensor

Patent metadata

Field	Value
Publication number	US-11609082-B2
Application number	US-201916575004-A
Country	US
Kind code	B2
Filing date	Sep 18, 2019
Priority date	Sep 21, 2018
Publication date	Mar 21, 2023
Grant date	Mar 21, 2023

Abstract

In some embodiments, a position sensor calibration and linearization system for position sensors is provided. A method of calibrating and linearization of a position sensor includes reading Spatial Angle data from a position sensor at a set of positions of a target swept over receive coils in the position sensor; calculating calibration parameters from the Spatial Angle data; determining an initial position values from the Spatial Angle data and the calibration parameters; determining linearization parameters from the initial position values; and writing the calibration parameters and the linearization parameters into the position sensor.

First claim

What is claimed is:

1. A method of calibrating and linearization of a position sensor, comprising:
rotating a target over the position sensor with a position motor to a set of positions, wherein a processor coupled to the position motor determines a location of each of the set of positions from the position motor;
reading, in the processor that is further coupled to the position sensor, Spatial Angle data from the position sensor at the set of positions of the target as the target is rotated over receive coils in the position sensor by the position motor;
calculating, in the processor, calibration parameters from the Spatial Angle data;
determining, in the processor, initial position values from the Spatial Angle data and the calibration parameters;
determining, in the processor, linearization parameters from the initial position values; and
writing, with the processor, the calibration parameters and the linearization parameters into the position sensor.

2. The method of claim 1 , wherein calculating calibration parameters from the Spatial Angle data includes determining a slope and an intercept from a line connected a first Spatial Angle and a last Spatial Angle.

3. The method of claim 2 , wherein determining linearization parameters includes determining a number of correction values at the number of points between the first Spatial Angle and the last Spatial Angle.

4. The method of claim 3 , wherein the number of correction values is determined to result in a least worst error of position measurements.

5. The method of claim 1 , wherein reading spatial angle data from the position sensor includes reading spatial angle data from a register in the position sensor.

6. The method of claim 1 , wherein writing the calibration parameters and the linearization parameters into the position sensor includes writing the calibration parameters and the linearization parameters into calibration and linearization registers in the position sensor.

7. A calibration and linearization system, comprising:
a processor; and
a position motor coupled to the processor, the position motor configured to move a target mounted to the position motor over a range of a position sensor positioned relative to the target,
wherein the processor executes instructions to
move the target over the position sensor to a set of positions, wherein the processor determines a location of each of the set of positions from the position motor;
read Spatial Angle data from the position sensor at the set of positions of a target swept over receive coils in the position sensor;
calculate calibration parameters from the Spatial Angle data;
determine initial position values from the Spatial Angle data and the calibration parameters;
determine linearization parameters from the initial position values; and
write the calibration parameters and the linearization parameters into the position sensor.

8. The system of claim 7 , wherein calculating calibration parameters from the Spatial Angle data includes determining a slope and an intercept from a line connected a first Spatial Angle and a last Spatial Angle.

9. The system of claim 8 , wherein determining linearization parameters includes determining a number of correction values at the number of points between the first Spatial Angle and the last Spatial Angle.

10. The system of claim 7 , wherein the processor is configured to read and write to registers in the position sensor.

11. The system of claim 10 , wherein the registers include a Spatial Angle register, calibration parameter registers, and linearization parameter registers.

Assignees

• Integrated Device Tech

Inventors

• Qama Gentjan
• Kiesel Peter

Classifications

• G01B7/30 Primary

  for measuring angles or tapers; for testing the alignment of axes · CPC title

• G01D5/2006

  by influencing the self-induction of one or more coils (G01D5/22 takes precedence) · CPC title

• G01B7/003

  for measuring position, not involving coordinate determination (coordinate measuring G01B7/004) · CPC title

• G01D18/008

  with calibration coefficients stored in memory · CPC title

• G01D5/2053 Primary

  by a movable non-ferromagnetic conductive element · CPC title