System and method for increasing sensor resolution using interpolation

• US 20060025959A1
• Filed: 07/12/2005
• Published: 02/02/2006
• Est. Priority Date: 07/12/2004
• Status: Active Grant

• Current Assignee: Immersion Corporation
• Original Assignee: Immersion Corporation
• Inventors: Grant, Danny, Gomez, Daniel H., Tierling, Kollin M.
• Granted Patent: US 7,386,415 B2
• Time in Patent Office: Days
• US Class Current: 702/150
• CPC Class Codes: G01D 5/24409 Interpolation using memories
• CPC Class Codes: G06F 3/0362 with detection of 1D translations or rotations of an operating part of the device, e.g. scroll wheels, sliders, knobs, rollers or belts
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

Systems and methods for increasing sensor resolution using interpolation are described. One described method includes receiving an analog sensor signal associated with a coding surface; deriving a quadrature signal based at least in part on an analog threshold voltage associated with the analog sensor signal; determining a velocity and a derived quadrature position of the coding surface based at least in part on the quadrature signal; outputting the derived quadrature position of the coding surface if the velocity exceeds a velocity threshold; and determining and outputting an interpolated position of the coding surface using analog interpolation if the velocity is less than or equal to the velocity threshold.

Claims

1. A method comprising:

receiving an analog sensor signal associated with a coding surface;

deriving a quadrature signal based at least in part on an analog threshold voltage associated with the analog sensor signal;

determining a velocity and a derived quadrature position of the coding surface based at least in part on the quadrature signal;

outputting the derived quadrature position of the coding surface if the velocity exceeds a velocity threshold; and

determining and outputting an interpolated position of the coding surface using analog interpolation if the velocity is less than or equal to the velocity threshold.

2. The method of claim 1, further comprising:

receiving a first waveform associated with a first aperture of the coding surface;

receiving a second waveform associated with a second aperture of the coding surface;

determining an average waveform associated with the first waveform and the second waveform.

3. The method of claim 1, further comprising outputting the interpolated position of the coding surface as user input to a device.

4. The method of claim 1, further comprising determining a haptic effect to be generated based at least in part on the interpolated position on the coding surface.

5. A system comprising:

a sensor configured to sense the motion of a coding surface;

a quadrature counter in communication with the sensor and operable to determine a quadrature position of the coding surface;

a processor in communication with the sensor and the quadrature counter, the processor operable to;

determine a velocity of the coding surface;

output the quadrature position of the coding surface if the velocity exceeds a velocity threshold;

determine and output an interpolated position of the coding surface using analog interpolation if the velocity is less than or equal to the velocity threshold.

6. The system of claim 5, further comprising a user input device in communication with the coding surface.

7. The system of claim 6, wherein the device comprises one of a phone, a PDA, a camera, an automotive entertainment system, or a DVD player.

8. The system of claim 5, wherein the interpolated position is associated with a position of a manipulandum.

9. The system of claim 8, wherein the manipulandum comprises a knob.

10. The system of claim 5, wherein the interpolated position comprises an angular position in a rotational degree of freedom.

11. The system of claim 5, wherein the interpolated position comprises a linear position in a linear degree of freedom.

12. The system of claim 5, further comprising a housing configured to house the processor, sensor, and quadrature counter.

13. A method comprising:

receiving a sensor signal;

determining at least two reference signals associated with the sensor signal, each of the at least two reference signals associated with a measured position;

calculating a measured signal trajectory angle associated with the sensor signal;

determining a stored signal trajectory angle associated with each of the at least two reference signals; and

correlating the measured signal trajectory angle to the stored signal trajectory angle associated with each of the at least two reference signals to determine an interpolated position.

14. The method of claim 13, further comprising

receiving the at least two reference signals and the measured position;

and

storing the at least two reference signals and the measured position.

15. The method of claim 13, wherein correlating the measured signal trajectory angle to the stored signal trajectory angle comprises applying a weighting function, the weighting function derived from a rate of change associated with the sensor value.

16. The method of claim 13, wherein correlating the measured signal trajectory angle to the stored signal trajectory angle comprises:

determining a point cloud including the at least two reference signals;

selecting at least one nearest neighbor from the point cloud, the selection comprising minimizing the least squared distance between the sensor signal and the at least one nearest neighbor.

18. The method of claim 13, further comprising:

detecting an index aperture based in a deviation in phase trajectory of the sensor signal.

17. The method of claim 17, further comprising:

minimizing the least squared error between the sensor signal and the at least one nearest neighbor.

19. A method comprising:

receiving a sensor signal associated with a rotational position of a coding surface, the sensor signal having a first amplitude;

determining a reference signal associated with the sensor signal, the reference signal having a second amplitude; and

determining an axial position of the coding surface based on the difference between the first amplitude and the second amplitude.

20. A computer-readable medium on which is encoded program code, the program code comprising:

program code for receiving an analog sensor signal associated with a coding surface;

program code for deriving a quadrature signal based at least in part on an analog threshold voltage associated with the analog sensor signal;

program code for determining a velocity and a derived quadrature position of the coding surface based at least in part on the quadrature signal;

program code for outputting the derived quadrature position of the coding surface if the velocity exceeds a velocity threshold; and

program code for determining and outputting an interpolated position of the coding surface using analog interpolation if the velocity is less than or equal to the velocity threshold.

21. A computer-readable medium on which is encoded program code, the program code comprising:

program code for receiving a sensor signal;

program code for determining at least two reference signals associated with the sensor signal, each of the at least two reference signals associated with a measured position;

program code for calculating a measured signal trajectory angle associated with the sensor signal;

program code for determining a stored signal trajectory angle associated with each of the at least two reference signals; and

program code for correlating the measured signal trajectory angle to the stored signal trajectory angle associated with each of the at least two reference signals to determine an interpolated position.

22. A computer-readable medium on which is encoded program code, the program code comprising:

program code for receiving a sensor signal associated with a rotational position of a coding surface, the sensor signal having a first amplitude;

determining a reference signal associated with the sensor signal, the reference signal having a second amplitude;

determining an axial position of the coding surface based on the difference between the first amplitude and the second amplitude.