Method of determining the planar inclination of a surface

• US 6,259,519 B1
• Filed: 08/31/1999
• Issued: 07/10/2001
• Est. Priority Date: 08/31/1999
• Status: Expired due to Fees

• Current Assignee: Intelligent Machine Concepts LLC
• Original Assignee: Intelligent Machine Concepts LLC
• Inventors: Hooker, Jeff, Simmons, Steve
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US09/386,830
• Time in Patent Office: 679 Days
• Field of Search: 356/139.03, 356/152.2, 356/376, 702/152-154
• US Class Current: 356/139.03
• CPC Class Codes: G01B 11/26 for measuring angles or tapers; for testing the alignment of axes
• CPC Class Codes: G01C 11/025 by scanning the object
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105

Abstract

A method of determining the planar inclination of a surface is disclosed. Each of three lasers positioned within a sensor body are modulated with different sine wave frequencies based on stored values within a wave-table by superimposing onto the emitted light beam a respective sine wave frequency. The light beam is scattered from each laser onto a respective position sensitive detector after being emitted onto a surface to be analyzed. The light beam is then demodulated by producing electrical signals from each respective position sensitive detector and integrating the electrical signals and calculating the planar inclination on the surface based on demodulated values.

Claims

1. A method of determining the planar inclination of a surface comprising the steps of:

modulating each of three lasers positioned within a sensor body with a different sine wave frequency based on stored values within a wave-table by superimposing onto the emitted light beam from each laser the respective sine wave frequency;

emitting the light beam from each laser onto a surface to be analyzed;

scattering the light beam emitted from each laser onto a respective position sensitive detector formed from a semiconductor chip that is positioned within the sensor body;

demodulating each light beam by;

producing electrical signals from each respective position sensitive detector corresponding to the position of the scattered light beam, and

integrating the electrical signals by values in the wave-table to obtain demodulated values; and

calculating the planar inclination of the surface based on the demodulated values.

2. A method according to claim 1, and further comprising the step of generating the sine wave frequencies within a digital signal processor.

3. A method according to claim 1, and further comprising the step of operating the digital signal processor in discrete time and phase locking with the scattered light beam signals.

4. A method according to claim 1, wherein the step of calculating further comprises the step of integrating over a base frequency.

5. A method according to claim 1, wherein the sine wave frequencies are produced as frequencies that are prime relative to each other.

6. A method according to claim 1, wherein the step of producing electrical signals further comprises the step of producing two signals corresponding to respective sides of the position sensitive detector.

7. A method of determining the planar inclination of a surface comprising the steps of:

modulating each of three lasers positioned within a longitudinally extending sensor body with a different sine wave frequency based on stored values within a wave-table by superimposing onto the emitted light beam from each laser the respective sine wave frequency;

emitting the light beam from each laser in a longitudinal direction substantially parallel to the longitudinal axis defined by the sensor body onto a surface to be analyzed;

scattering the light beam emitted from each laser into a respective position sensitive detector formed from a semiconductor chip that is positioned within the sensor body;

demodulating each light beam by;

producing electrical signals from each respective position sensitive detector corresponding to the position of the scattered light beam, and

integrating the electrical signals by values in the wave-table to obtain demodulated values; and

calculating the planar inclination of the surface based on the demodulated values.

8. A method according to claim 7, and further comprising the step of generating the sine wave frequencies within a digital signal processor.

9. A method according to claim 7, and further comprising the step of operating the digital signal processor in discrete time and phase locking with the scattered light beam signals.

10. A method according to claim 7, wherein the step of calculating further comprises the step of integrating over a base frequency.

11. A method according to claim 7, wherein the sine wave frequencies are produced as frequencies that are prime to each other.

12. A method according to claim 7, wherein the step of producing electrical signals further comprises the step of producing two signals corresponding to respective sides of the position sensitive detector.

13. A method of determining the planar inclination of a surface for robot arm manipulation comprising the steps of:

modulating each of three lasers positioned within a sensor body with a different sine wave frequency based on stored values within a wave-table by superimposing onto the emitted light beam from each laser the respective sine wave frequency;

emitting the light beam from each laser onto a surface to be analyzed;

scattering the light beam emitted from each laser into a respective position sensitive detector formed from a semiconductor chip that is positioned within the sensor body;

demodulating each light beam by;

producing electrical signals from each respective position sensor detector corresponding to the position of the scattered light beam, and

integrating the signals by values in the wave-table to obtain demodulated values;

calculating the planar inclination of the surface based on the demodulated values; and

controlling manipulation of a robot arm based on the calculated planar inclination.

14. A method according to claim 13, and further comprising the step of generating the sine wave frequencies within a digital signal processor.

15. A method according to claim 13, and further comprising the step of operating the digital signal processor in discrete time and phase locking with the returned light beam signals.

16. A method according to claim 13, wherein the step of calculating further comprises the step of integrating over a base frequency.

17. A method according to claim 13, wherein the sine wave frequencies are produced as frequencies that are prime to each other.

18. A method according to claim 13, wherein the step of producing electrical signals further comprises the step of producing two signals corresponding to respective sides of the position sensitive detector.

20. A method according to claim 17, and further comprising the step of generating the sine wave frequencies within a digital signal processor.

19. A method of determining the planar inclination of a surface for robot arm manipulation comprising the steps of:

modulating each of three lasers positioned within a longitudinally extending sensor body with a different sine wave frequency based on stored values within a wave-table by superimposing onto the emitted light beam from each laser the respective sine wave frequency;

emitting the light beam from each laser in a longitudinal direction substantially parallel to the longitudinal axis defined by the sensor body onto a surface to be analyzed;

scattering the light beam emitted from each laser into a respective position sensitive detector formed from a semiconductor chip that is positioned within the sensor body;

demodulating each light beam by;

producing electrical signals from each respective position sensitive detector corresponding to the position of the returned light beam, and

integrating top and bottom signals by values in the wave-table to obtain demodulated values;

calculating the planar inclination of the surface based on the demodulated values; and

controlling the manipulation of a robot arm based on the calculated planar inclination.

21. A method according to claim 19, and further comprising the step of operating the digital signal processor in discrete time and phase locking with the returned light beam signals.

22. A method according to claim 19, wherein the step of calculating further comprises the step of integrating over a base frequency.

23. A method according to claim 19, wherein the sine wave frequencies are produced as frequencies that are prime to each other.

24. A method according to claim 19, wherein the step of producing electrical signals further comprises the step of producing two signals corresponding to respective sides of the position sensitive detector.