Positioning method and positioning system based on light intensity

• US 9,405,000 B2
• Filed: 11/01/2012
• Issued: 08/02/2016
• Est. Priority Date: 03/06/2009
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Lu, Che-Yen, Yeh, Lun-Wu, Lee, Yueh-Feng, Lin, Yu-Hsuan, Tseng, Yu-Chee
• Primary Examiner(s): Bryant, Rebecca C
• Application Number:
  US13/665,939
• Publication Number:
  US 20130088725A1
• Time in Patent Office: 1,370 Days
• Field of Search: 356/615, 356/623, 315149-155
• US Class Current: 1/1
• CPC Class Codes: G01B 11/03 by measuring coordinates of points
• CPC Class Codes: G01B 11/245 using a plurality of fixed, simultaneously operating transducers G01B11/2408 - G01B11/2425, G01B11/255 take precedence
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G01S 5/08 Position of single direction-finder fixed by determining direction of a plurality of spaced sources of known location
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308
• CPC Class Codes: G01S 5/16 using electromagnetic waves other than radio waves

Abstract

A positioning method and a positioning system based on light intensity are provided. The positioning system comprises a lighting system, a sense feedback device and a positioning module. The lighting system comprises at least three point light sources and sequentially adjusts luminance of these point light sources to light up a target. The sense feedback device is disposed on the target and used to collect light intensity information of the light projected on the target by the lighting system. The positioning module calculates a distance between the target and each of the point light sources based on the light intensity information and calculates a positioning location of the target based on the locations of the point light sources and the distances between the target and the point light sources.

Claims

1. A positioning method based on light intensity, comprising:

sequentially adjusting luminance of three point light sources of a lighting system located on a first surface to obtain changes of luminance for each of the three point light sources and detecting, by a target located on the first surface, changes of light intensities from the three point light sources in response to the changes of luminance;

calculating a distance between each of the three point light sources and the target based on the changes of luminance and the changes of light intensities;

setting up spherical equations using a position of each of the three point light sources as a center and using the distance between each of the three point light sources and the target as a radius; and

calculating a position of the target by solving the spherical equations.

2. The positioning method based on light intensity of claim 1, wherein the step of sequentially adjusting luminance of the three point light sources of the lighting system located on the first surface to obtain the changes of luminance for each of the three point light sources and detecting, by the target located on the first surface, the changes of light intensities from the three point light sources in response to the changes of luminance comprises:

adjusting the luminance of one of the point light sources to be a first luminance;

sensing a first light intensity of the light detected by the target;

adjusting the luminance of the one of the point light sources to be a second luminance;

sensing a second light intensity of the light detected by the target; and

repeating above steps for other two of the three point light sources so as to obtain the changes of light intensities detecting, by the target located on the first surface, based on the changes of luminance for each of the three point light sources.

3. The positioning method based on light intensity of claim 1, wherein the step of calculating the distance between each of the three point light sources and the target based on the changes of luminance and the changes of light intensities comprises:

obtaining a height of the lighting system;

calculating a first result by multiplying the changes of luminance by the height and dividing by the changes of light intensities; and

taking a cube root of the first result to obtain the distance.

4. The positioning method based on light intensity of claim 1, wherein the step of setting up the spherical equations using the position of each of the three point light sources as the center and using the distance as the radius comprises:

selecting two spheres projected onto the first surface using the position of each of the three point light sources as the center and using the distance as the radius; and

locating at least one intersection between the two spheres.

5. The positioning method based on light intensity of claim 1, wherein the method further comprises:

adjusting an irradiation angle of each of the point light sources of the lighting system, so as to make the point light sources face the target.

6. The positioning method based on light intensity of claim 5, wherein the step of adjusting an irradiation angle of each of the point light sources of the lighting system, so as to make the point light sources face the target comprises:

respectively calculating a relative angle of each of the point light sources with respect to the target according to a location of each of the point light sources and a location of the target;

respectively calculating an included angle between the relative angle of each of the point light sources and the irradiation angle; and

shifting each of the point light sources by the corresponding included angle so as to make a front of each of the point light sources face the target.

7. The positioning method based on light intensity of claim 1, wherein the method further comprises:

shifting the location of the lighting system so as to make an average of the distances between each of the point light sources and the target is the shortest.

8. The positioning method based on light intensity of claim 1, wherein after the step of calculating the position of the target by solving the spherical equations, the method further comprises:

receiving a light intensity value inputted by a user; and

adjusting the luminance of each of the point light sources of the lighting system, so as to make the light intensity of the light received by the target to match the light intensity value inputted by the user.

9. The positioning method based on light intensity of claim 8, wherein before the step of adjusting the luminance of each of the point light sources of the lighting system, so as to make the light intensity of the light received by the target to match the light intensity value inputted by the user, the method further comprises:

adjusting an irradiation angle of each of the point light sources of the lighting system, so as to make the point light sources face the target.

10. The positioning method based on light intensity of claim 8, wherein before the step of adjusting the luminance of each of the point light sources of the lighting system, so as to make the light intensity of the light received by the target to match the light intensity value inputted by the user, the method further comprises:

shifting the position of the lighting system, so as to make an average of the distances between the target and each of the point light sources is the shortest.

11. The positioning method based on light intensity of claim 8, wherein before the step of adjusting the luminance of each of the point light sources of the lighting system, so as to make the light intensity of the light received by the target to match the light intensity value inputted by the user, the method further comprises:

adjusting the luminance of the point light sources according to the distance between the target and each of the point light sources, so as to make the luminance of the point light source which is closest to the target be greater than the luminance of the other point light sources.

12. A positioning system based on light intensity, comprising:

a lighting system, comprising three point light sources, the lighting system sequentially adjusting luminance of the three point light sources of the lighting system located on a first surface to obtain changes of luminance for each of the three point light sources;

a sense feedback device detecting, by a target located on the first surface, changes of light intensities from the three point light sources in response to the changes of luminance; and

a positioning module calculating a distance between each of the three point light sources and the target based on the changes of luminance and the changes of light intensities, setting up spherical equations using a position of each of the three point light sources as a center and using the distance between each of the three point light sources and the target as a radius, and calculating a position of the target by solving the spherical equations.

13. The positioning system based on light intensity of claim 12, wherein the lighting system, comprising the three point light sources, the lighting system sequentially adjusting luminance of the three point light sources of the lighting system located on the first surface to obtain the changes of luminance for each of the three point light sources comprises:

adjusting the luminance of one of the point light sources to be a first luminance and recording a change of luminance for the one of the point light sources; and

repeating above steps for other two of the three point light sources so as to obtain the changes of luminance for each of the three point light sources.

14. The positioning system based on light intensity of claim 13, wherein the sense feedback device detecting, by the target located on the first surface, the changes of light intensities from the three point light sources in response to the changes of luminance comprises:

detecting by the target a first change of light intensity from the adjusting the luminance of one of the point light sources; and

detecting by the target a second change of light intensity and a third change of light intensity from the adjusting the luminance of the other two of the three point light sources so as to detect the changes of light intensities from the three point light sources.

15. The positioning system based on light intensity of claim 12, wherein the positioning module calculates the distance by obtaining a height of the lighting system, calculates a first result by multiplying the changes of luminance by the height and dividing by the changes of light intensities;

and takes a cube root of the first result to obtain the distance.

16. The positioning system based on light intensity of claim 12, wherein the positioning module sets up the spherical equations by selecting two spheres projected onto the first surface using the position of each of the three point light sources as the center and using the distance between each of the three point light sources and the target as the radius, and locates at least one intersection between the two spheres.

17. The positioning system based on light intensity of claim 12, wherein the positioning module is disposed on the sense feedback device.

18. The positioning system based on light intensity of claim 17, wherein the sense feedback device comprises:

a light intensity sensor sensing a light intensity information of the light projected by the lighting system so as to provide the light intensity information to the positioning module; and

a data transmission module sending positioning location calculated by the positioning module to the lighting system.

19. The positioning system based on light intensity of claim 18, wherein the lighting system further comprises:

a first control unit adjusting an irradiation angle of each of the point light sources according to the positioning location of the sense feedback device, so as to make the point light sources face the sense feedback device.

20. The positioning system based on light intensity of claim 19, wherein the first control unit respectively calculates a relative angle of each of the point light sources with respect to the sense feedback device according to the positioning location of the sense feedback device and the location of each of the point light sources, calculates an included angle between the relative angle of each of the point light sources and the irradiation angle, and shifts each of the point light sources by the corresponding included angle, so as to make a front of each of the point light sources face the sense feedback device.

21. The positioning system based on light intensity of claim 18, wherein the lighting system further comprises:

a second control unit shifting the position of each of the point light sources so as to make an average of the distances between each of the point light sources and the sense feedback device being the shortest.

22. The positioning system based on light intensity of claim 18, wherein the sense feedback device further comprises:

an input unit receiving a light intensity value inputted by a user.

23. The positioning system based on light intensity of claim 22, wherein the data transmission module further sends the light intensity value received by the input unit to the lighting system.

24. The positioning system based on light intensity of claim 23, wherein the lighting system further comprises:

a third control unit adjusting the luminance of each of the point light sources, so as to make the light intensity of the light received by the sense feedback device match the light intensity value inputted by the user.

25. The positioning system based on light intensity of claim 24, wherein the third control unit adjusts the luminance of the point light sources according to the distances between the point light sources and the sense feedback device, so as to make the luminance of the point light source, which is closest to the sense feedback device, be greater than the luminance of the other point light sources.

26. The positioning system based on light intensity of claim 12, wherein the positioning module is disposed on the lighting system.

27. The positioning system based on light intensity of claim 26, wherein the sense feedback device comprises:

a light intensity sensor sensing a light intensity information of the light projected by the lighting system, so as to provide the light intensity information to the positioning module; and

a data transmission module sending the positioning location collected by the sense feedback device to the lighting system for the positioning module to calculate the positioning location of the sense feedback device.

28. The positioning system based on light intensity of claim 27, wherein the lighting system further comprises:

a fourth control unit adjusting an irradiation angle of each of the point light sources according to the positioning location of the sense feedback device, so as to make the point light sources face the sense feedback device.

29. The positioning system based on light intensity of claim 28, wherein the fourth control unit respectively calculates a relative angle of each of the point light sources with respect to the sense feedback device according to the position of each of the point light sources and a positioning location the sense feedback device, calculates an included angle between the relative angle corresponding to each of the point light sources and the irradiation angle, and shifts each of the point light sources by the corresponding included angle, so as to make a front of each of the point light sources face the sense feedback device.

30. The positioning system based on light intensity of claim 27, wherein the lighting system further comprises:

a fifth control unit shifting the position of each of the point light sources, so as to make an average of the distances between each of the point light sources and the sense feedback device being the shortest.

31. The positioning system based on light intensity of claim 27, wherein the sense feedback device further comprises:

an input unit receiving a light intensity value inputted by a user.

32. The positioning system based on light intensity of claim 31, wherein the data transmission module further sends the light intensity value received by the input unit to the lighting system.

33. The positioning system based on light intensity of claim 32, wherein the lighting system further comprises:

a sixth control unit adjusting luminance of each of the point light sources, so as to make the light intensity of the light received by the sense feedback device match the light intensity value inputted by the user.

34. The positioning system based on light intensity of claim 32, wherein the sixth control unit adjusts the luminance of the point light sources according to the distances between the point light sources and the sense feedback device, so as to make the luminance of the point light source, which is closest to the sense feedback device, be greater than the luminance of the other point light sources.