Sensors, systems and methods for position sensing

• US 8,405,824 B2
• Filed: 03/18/2011
• Issued: 03/26/2013
• Est. Priority Date: 09/20/2008
• Status: Active Grant

• Current Assignee: Baanto International Ltd.
• Original Assignee: Baanto International Ltd.
• Inventors: Utukuri, Avanindra, Clarke, Jonathan
• Primary Examiner(s): NGUYEN, TU T
• Application Number:
  US13/051,898
• Publication Number:
  US 20110170088A1
• Time in Patent Office: 739 Days
• Field of Search: None
• US Class Current: 356/138
• CPC Class Codes: G01J 1/4257 applied to monitoring the characteristics of a beam, e.g. laser beam, headlamp beam monitoring arrangements for lasers in general H01S3/0014
• CPC Class Codes: G01S 3/782 Systems for determining direction or deviation from predetermined direction
• CPC Class Codes: G01S 3/784 using a mosaic of detectors
• CPC Class Codes: G01S 5/16 using electromagnetic waves other than radio waves

Abstract

Various systems and methods for estimating the position of a radiation source in three-dimensional space, together with sensors for use in such systems are described. In some embodiments, the systems include a plurality of radiation sensors. The three-dimensional position of the radiation source is estimated relative to each sensor using an aperture that casts shadows on a radiation detector as a function of the incident angle of the incoming radiation. In some embodiments, the ratio of a reference radiation intensity to a measured radiation intensity is used to estimate direction of the radiation source relative to the sensor. When the angular position of the radiation source is estimated relative to two sensors, the position of the radiation source in three dimensions can be triangulated based on the known relative positions of the two sensors.

Claims

1. A sensor for estimating the angular direction of a radiation source relative to the sensor, the sensor comprising:

a reference radiation detector for providing a reference radiation intensity signal corresponding to an intensity of radiation incident on the reference radiation detector;

a first direction radiation detector for providing a first direction radiation intensity signal corresponding to an intensity of radiation incident on the first direction radiation detector;

a second direction radiation detector for providing a second direction radiation intensity signal corresponding to an intensity of radiation incident on the second direction radiation detector;

a radiation stop for partially blocking radiation from reaching the first and second direction radiation detectors; and

a processor coupled to the reference radiation detector and to the first and second direction radiation detectors for providing first and second incident angles wherein the first incident angle corresponds to the first direction radiation intensity signal and the reference radiation intensity signal and the second incident angle corresponds to the second direction radiation intensity signal and the reference radiation intensity signal.

2. The sensor of claim 1 comprising:

a pair of first direction radiation detectors for providing a pair of first direction radiation intensity signals corresponding respectively to an intensity of radiation incident on each of the first direction radiation detectors; and

a pair of second direction radiation detectors for providing a pair of second direction radiation intensity signals corresponding respectively to an intensity of radiation incident on each of the second direction radiation detectors,

wherein the first incident angle corresponds to the first direction radiation intensity signals and the reference radiation intensity signal and the second incident angle corresponds to the second direction radiation intensity signals and the reference radiation intensity signal.

3. A sensor for estimating the angular direction of a radiation source relative to the sensor, the sensor comprising:

a reference radiation detector for providing a reference radiation intensity signal corresponding to an intensity of radiation incident on the reference radiation detector;

a pair of directional radiation detectors for providing a pair of directional radiation intensity signal corresponding to an intensity of radiation incident on the first direction radiation detector;

a radiation stop for partially blocking radiation from reaching the first and second direction radiation detectors; and

a processor coupled to the reference radiation detector and to the directional radiation detectors for providing an incident angle, wherein the incident angle corresponds to the directional radiation intensity signals and the reference radiation intensity signal.

4. A sensor for estimating the angular direction of a radiation source relative to the sensor, the sensor comprising:

a pixel array detector having an array of a pixels sensitive to radiation;

an aperture plate having an aperture, wherein the aperture plate is arranged relative to the pixel array detector to partially blocking radiation from reaching the pixel array detector; and

a processor coupled to the pixel array detector to receive radiation intensity information relating to the intensity of radiation incident on the pixels of the pixel array detector, wherein the processor is adapted to provide first and second incident angles, wherein the first incident angle is corresponds to the position of one or more pixels having a relatively high level of incident radiation in a first direction and the second incident angle corresponds to the position of one or more pixels have a relatively high level of incident radiation in a second direction.

5. A system for estimating the position of a radiation source in three dimensional space, the system comprising:

a first radiation sensor for receiving radiation from the radiation source and for providing a first incident angle pair corresponding to the direction of the radiation source relative to the first radiation source;

a second radiation sensor for receiving radiation from the radiation source and for providing a second incident angle pair corresponding the direction of the radiation source relative to the second radiation source; and

a processor for calculating the estimated position of the radiation source based on the first and second incident angle pairs,

wherein the processor is adapted to calculate the estimated position of the radiation source by determining a point of intersection between a first line defined by the first incident angle pair and the position of the first radiation sensor and a second line defined by the second incident angle pair and the second radiation sensor.

6. The system of claim 5 wherein the first and second sensors are mounted in a fixed relationship to one another.

7. The system of claim 5 wherein the first and second sensors may be independently positioned relative to one another.

8. A system for estimating the position of a radiation source in three dimensional space, the system comprising:

a first radiation sensor for receiving radiation from the radiation source and for providing a first incident angle pair corresponding to the direction of the radiation source relative to the first radiation source;

a second radiation sensor for receiving radiation from the radiation source and for providing a second incident angle pair corresponding the direction of the radiation source relative to the second radiation source; and

a processor for calculating the estimated position of the radiation source based on the first and second incident angle pairs,

wherein the processor is adapted to calculate the estimated position of the radiation source by identifying a line segment between the closest points between a first line defined by the first incident angle pair and the position of the first radiation sensor and a second line defined by the second incident angle pair and the second radiation sensor.

9. The system of claim 8 wherein the processor is adapted to calculate the estimate position of the radiation source by bisecting the line segment.

10. The system of claim 8 wherein the first and second sensors are mounted in a fixed relationship to one another.

11. The system of claim 8 wherein the first and second sensors may be independently positioned relative to one another.

12. A method of estimating the position of a radiation source, comprising:

positioning first and second sensors in a three dimensional space, wherein the first second sensor are separated by a sensor spacing distance;

calculating a first line corresponding to the position of the first sensor and the position of the radiation source;

calculating a second line corresponding to the position of the second sensor and the position of the radiation source; and

calculating an estimated position of the radiation source based on the first and second lines,

wherein the position of the radiation source is estimated by identifying a point of intersection between the first and second lines.

13. A method of estimating the position of a radiation source, comprising:

positioning first and second sensors in a three dimensional space, wherein the first second sensor are separated by a sensor spacing distance;

calculating a first line corresponding to the position of the first sensor and the position of the radiation source;

calculating a second line corresponding to the position of the second sensor and the position of the radiation source; and

calculating an estimated position of the radiation source based on the first and second lines,

wherein the position of the radiation source is estimated by identifying a line segment between the closest points on the first and second lines.

14. The method of claim 13 wherein the position of the radiation source is estimated by bisecting the line segment.