3-Point positioning device and method thereof

• US 20100284548A1
• Filed: 04/28/2010
• Published: 11/11/2010
• Est. Priority Date: 05/08/2009
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: PixArt Imaging Incorporated
• Inventors: Cheng, Hsin-Chi, Hsu, En-Feng, Lu, Chih-Hung, Kao, Ming-Tsan
• Granted Patent: US 8,406,433 B2
• Time in Patent Office: Days
• US Class Current: 381/107
• CPC Class Codes: G01B 11/026 by measuring distance between sensor and object G01B11/0608 takes precedence
• CPC Class Codes: G01B 11/26 for measuring angles or tapers; for testing the alignment of axes
• CPC Class Codes: H03G 3/301 the gain being continuously variable

Abstract

A 3-point positioning device senses a scene including an auxiliary positioning module by means of an image sensor, and accordingly generates a sensed image. The auxiliary positioning module comprises a first, a second, and a third auxiliary positioning units. By means of the sensed image, the 3-point positioning device recognizes a first, a second, and a third sensing units of the image sensor corresponding to the first, the second, and the third auxiliary positioning units. In this way, the 3-point positioning device can calculate out an absolute location of the auxiliary positioning module according to the locations or the received power of the first, the second, and the third sensing units.

Claims

1. A 3-point positioning device, comprising:

an auxiliary positioning module, comprising;

a first auxiliary positioning unit;

a second auxiliary positioning unit; and

a third auxiliary positioning unit;

wherein a first auxiliary positioning line is formed between the first auxiliary positioning unit and the second auxiliary positioning unit;

wherein a length of the first auxiliary positioning line is equal to a first predetermined distance;

wherein a second auxiliary positioning line is formed between the second auxiliary positioning unit and the third auxiliary positioning unit;

wherein a length of the second auxiliary positioning line is equal to a second predetermined distance;

wherein an included angle between the first and the second auxiliary positioning lines is a predetermined included angle;

an image sensor, for sensing a scene having a range including the first, the second, and the third auxiliary positioning unit, and accordingly generating a sensed image;

wherein the range of the scene is determined by a predetermined view angle of the image sensor; and

a location-calculating circuit, for receiving the sensed image so as to recognize a first sensing unit of the image sensor corresponding to the first auxiliary positioning unit, a second sensing unit of the image sensor corresponding to the second auxiliary positioning unit, and a third sensing unit of the image sensor corresponding to the third auxiliary positioning unit, and calculating out a measured distance and a measured angle between the auxiliary positioning module and the image sensor according the first, the second, and the third sensing units so as to accordingly output a distance/angle signal.

2. The 3-point positioning device of claim 1, wherein the first, the second, and the third auxiliary positioning units are Light-Emitting Diodes (LED) having a specific wavelength or a specific frequency, or the first, the second, and the third auxiliary positioning units are objects having a specific pattern or a specific color.

3. The 3-point positioning device of claim 1, wherein a first projection line is formed between the first sensing unit and the first auxiliary positioning unit;

a second projection line is formed between the second sensing unit and the second auxiliary positioning unit;

a third projection line is formed between the third sensing unit and the third auxiliary positioning unit;

the first, the second, and third projection lines cross with each other at a crossing point;

the crossing point is projected at a middle point of the image sensor;

a middle line is formed between the crossing point and the middle point of the image sensor;

the middle line is perpendicular to a surface of the image sensor.

4. The 3-point positioning device of claim 3, wherein the location-calculating circuit calculated out the measured distance and the measured object according to following formulas:

D₆₁₂/sin θ

₆₁₂=D_M/sin (2×

π

−

θ

_M−

θ

₆₁₂−

θ

₆₂₃−

θ

_Y); and

D₆₂₃/sin θ

₆₂₃=DM/sin θ

_M;

wherein D₆₁₂ represents the first predetermined distance;

D₆₂₃ represents the second predetermined distance;

D_M represents the measured distance;

θ

_M represents the measured angle;

π

represents a sum of three internal angles of a triangle;

θ

₆₁₂ represents a first projection included angle between the first and the second projection lines;

θ

₆₂₃ represents a second projection included angle between the second and the third projection lines;

θ

_Y represents the predetermined included angle.

5. The 3-point positioning device of claim 4, wherein the location-calculating circuit calculates out a first middle-line included angle between the first projection line and the middle line, a second middle-line included angle between the second projection line and the middle line, and a third middle-line included angle between the third projection line and the middle line according to following formulas:

θ

_A=tan<sup>−

1</sup>[tan(θ

_FOV/2)×

(D_S1F/D_FOV/2)];

θ

_B=tan<sup>−

1</sup>[tan(θ

_FOV/2)×

(D_S2F/D_FOV/2)]; and

θ

_C=tan<sup>−

1</sup>[tan(θ

_FOV/2)×

(D_S3F/D_FOV/2)];

wherein θ

_A represents the first middle-line included angle;

θ

_B represents the second middle-line included angle;

θ

_C represents the third middle-line included angle;

D_S1F represents a distance between the middle point and the first sensing unit;

D_S2F represents a distance between the middle point and the second sensing unit;

D_S3F represents a distance between the middle point and the third sensing unit;

D_FOV/2 represents a half of a width of the image sensor.

6. The 3-point positioning device of claim 5, wherein when the middle point is between the first and the second sensing units, the location-calculating circuit calculates out the first and the second projection included angles as following formulas:

θ

₆₁₂=θ

_A+θ

_B; and

θ

₆₂₃=θ

_C−

θ

_B.

7. The 3-point positioning device of claim 5, wherein when the middle point is between the second and the third sensing units, the location-calculating circuit calculates out the first and the second projection included angles as following formulas:

θ

₆₁₂=θ

_A−

θ

_B; and

θ

₆₂₃=θ

_C+θ

_B.

8. The 3-point positioning device of claim 5, wherein when the first, the second, and the third sensing units are at a same side of the middle point, and the first middle-line included angle is larger than second middle-line included angle, and the second middle-line included angle is larger than the third middle-line included angle, the location-calculating circuit calculates out the first and the second projection included angles as following formulas:

θ

₆₁₂=θ

_A−

θ

_B; and

θ

₆₂₃=θ

_B+θ

_C.

9. The 3-point positioning device of claim 5, wherein when the first, the second, and the third sensing units are at a same side of the middle point, and the third middle-line included angle is larger than the second middle-line included angle, and the second middle-line included angle is larger than the first middle-line included angle, the location-calculating circuit calculates out the first and the second projection included angles as following formulas:

θ

₆₁₂=θ

_B−

θ

_A; and

θ

₆₂₃=θ

_C−

θ

_B.

10. The 3-point positioning device of claim 1, wherein the first predetermined distance is equal to the second predetermined distance;

the predetermined included angle is equal to a sum of three internal angles of a triangle;

the first, the second, and the third auxiliary positioning units are LEDs, and lights emitted by the first, the second, and the third auxiliary positioning units have a same power.

11. The 3-point positioning device of claim 10, wherein the location-calculating circuit calculates out the measured distance and the measured angle according to following formulas:

PW₇₃₂/PW₇₃₁=(D₇₃₁)²/(D_M)²;

PW₇₃₂/PW₇₃₃=(D₇₃₃)²/(D_M)²;

(D₇₃₁)²+(D₇₃₃)²=2×

[(D_A)²+(D_M)²];

(½

)×

D_A×

D₇₃₃×

sin θ

_M=[V×

(V−

D_A)×

(V−

D₇₃₃)×

(V−

D_M)]; and

V=(½

)×

(D_A+D₇₃₃+D_M);

wherein D_M represents the measured distance;

θ

_M represents the measured angle;

D_A represents the first predetermined distance or the second predetermined distance;

D₇₃₁ represents a distance between the first sensing unit and the first auxiliary positioning unit;

D₇₃₃ represents a distance between the third sensing unit and the third auxiliary positioning unit;

V represents a half of a perimeter of a triangle formed by the second auxiliary positioning line, the second projection line, and the third projection lines;

PW₇₃₁ represents a power of a received light of the first sensing unit;

PW₇₃₂ represents a power of a received light of the second sensing unit;

PW₇₃₃ represents a power of a received light of the third sensing unit.

12. The 3-point positioning device of claim 10, wherein the measured distance is a distance between the first sensing unit and the first auxiliary positioning unit, a distance between the second sensing unit and the second auxiliary positioning unit, or a distance between the third sensing unit and the third auxiliary positioning unit;

the measured angle is an included angle between a connecting line formed between the second sensing unit and the second auxiliary positioning unit, and the first auxiliary positioning line, an included angle between a connecting line formed between the second sensing unit and the second auxiliary positioning unit, and the second auxiliary positioning line, a included angle between a connecting line formed between the first sensing unit and the first auxiliary positioning unit, and the first auxiliary positioning line, or an included angle between a connecting line formed between the third sensing unit and the third auxiliary positioning unit, and the second auxiliary positioning line.

13. A speaker system, comprising:

a 3-point positioning device of claim 1;

a first speaker, for outputting a voice according to a first volume-controlling signal;

a second speaker, for outputting a voice according to a second volume-controlling signal; and

a volume controller, for receiving the distance/angle signal, and outputting the first and the second volume-controlling signals according to the measured distance and the measured angle for adjusting volumes of the voices outputted by the first and the second speakers.

14. The speaker system of claim 13, wherein the longer the measured distance is, the more the volume controller increases the volumes of the voices outputted by the first and the second speakers;

the shorter the measured distance is, the more the volume controller decreases the volumes of the voices outputted by the first and the second speakers.

15. The speaker system of claim 13, wherein the auxiliary positioning module is disposed between the first and the second speakers;

when the volume controller determines that the image sensor and the first speaker at a same side of the auxiliary positioning module according to the measured distance and the measured angle, the volume controller decreases the volume of the voice outputted by the first speaker and the increases the volume of the voice outputted by the second speaker;

when the volume controller determines that the image sensor and the first speaker at different sides of the auxiliary positioning module according to the measured distance and the measured angle, the volume controller increases the volume of the voice outputted by the first speaker and the decreases the volume of the voice outputted by the second speaker.

16. A method of 3-point positioning, comprising:

providing a first, a second, and a third auxiliary positioning units of an auxiliary positioning module, and an image sensor;

wherein a first auxiliary positioning line is formed between the first auxiliary positioning unit and the second auxiliary positioning unit;

wherein a length of the first auxiliary positioning line is equal to a first predetermined distance;

wherein a second auxiliary positioning line is formed between the second auxiliary positioning unit and the third auxiliary positioning unit;

wherein a length of the second auxiliary positioning line is equal to a second predetermined distance;

wherein an included angle between the first and the second auxiliary positioning lines is a predetermined included angle;

the image sensor sensing a scene for generating a sensed image;

wherein the first, the second, and the third auxiliary positioning units are in a range of the scene;

recognizing a first sensing unit of the image sensor corresponding to the first auxiliary positioning unit, a second sensing unit of the image sensor corresponding to the second auxiliary positioning unit, and a third sensing unit of the image sensor corresponding to the third auxiliary positioning unit, according to the sensed image; and

calculating out a measured distance and a measured angle between the image sensor and the auxiliary positioning module according to the first, the second, and the third sensing units.

17. The method of claim 16, wherein the first, the second, and the third auxiliary positioning units are LEDs having a specific wavelength or a specific frequency, or the first, the second, and the third auxiliary positioning units are objects having a specific pattern or a specific color.

18. The method of claim 17, wherein a first projection line is formed between the first sensing unit and the first auxiliary positioning unit;

a second projection line is formed between the second sensing unit and the second auxiliary positioning unit;

a third projection line is formed between the third sensing unit and the third auxiliary positioning unit;

the first, the second, and third projection lines cross with each other at a crossing point;

the crossing point is projected at a middle point of the image sensor;

a middle line is formed between the crossing point and the middle point of the image sensor;

the middle line is perpendicular to a surface of the image sensor;

the range of the scene is determined by a predetermined view angle of the image sensor.

19. The method of claim 18, wherein calculating out the measured distance and the measured angle between the image sensor and the auxiliary positioning module according to the first, the second, and the third sensing units comprises:

calculating out a first middle-line included angle between the first projection line and the middle line, a second middle-line included angle between the second projection line and the middle line, and a third middle-line included angle between the third projection line and the middle line, according the predetermined view angle, the middle line, and the first, the second, and the third sensing units;

calculating out a first projection included angle between the first and the second projection lines, and a second projection included angle between the second and the third projection lines, according to the first, the second, and the third middle-line included angles; and

calculating out the measured distance and the measured angle, according to the predetermined angle, the first predetermined distance, the second predetermined distance, the first projection included angle, and the second projection included angle.

20. The method of claim 19, wherein the measured distance and the measured angle is calculated out according to following formulas:

D₆₁₂/sin θ

₆₁₂=D_M/sin (2×

π

−

θ

_M−

θ

₆₁₂−

θ

₆₂₃−

θ

_Y); and

D₆₂₃/sin θ

₆₂₃=D_M/sin θ

_M;

wherein D₆₁₂ represents the first predetermined distance;

D₆₂₃ represents the second predetermined distance;

D_M represents the measured distance;

θ

_M represents the measured angle;

π

represents a sum of three internal angles of a triangle;

θ

₆₁₂ represents a first projection included angle between the first and the second projection lines;

θ

₆₂₃ represents a second projection included angle between the second and the third projection lines;

θ

_Y represents the predetermined included angle.

21. The method of claim 20, wherein the first, the second, and the third middle-line included angles are calculated out according to following formulas:

θ

_A=tan<sup>−

1</sup>[tan(θ

_FOV/2)×

(D_S1F/D_FOV/2)];

θ

_B=tan<sup>−

1</sup>[tan(θ

_FOV/2)×

(D_S2F/D_FOV/2)]; and

θ

_C=tan<sup>−

1</sup>[tan(θ

_FOV/2)×

(D_S3F/D_FOV/2)];

wherein θ

_A represents the first middle-line included angle;

θ

_B represents the second middle-line included angle;

θ

_C represents the third middle-line included angle;

D_S1F represents a distance between the middle point and the first sensing unit;

D_S2F represents a distance between the middle point and the second sensing unit;

D_S3F represents a distance between the middle point and the third sensing unit;

D_FOV/2 represents a half of a width of the image sensor.

22. The method of claim 21, wherein when the middle point is between the first and the second sensing units, the first and the second projection included angles are calculated out according to following formulas:

θ

₆₁₂=θ

_A+θ

_B; and

θ

₆₂₃=θ

_C−

θ

_B.

23. The method of claim 21, wherein when the middle point is between the second and the third sensing units, the first and the second projection included angles are calculated out according to following formulas:

θ

₆₁₂=θ

_A−

θ

_B; and

θ

₆₂₃=θ

_C+θ

_B.

24. The method of claim 21, wherein when the first, the second, and the third sensing units are at a same side of the middle point, and the first middle-line included angle is larger than second middle-line included angle, and the second middle-line included angle is larger than the third middle-line included angle, the first and the second projection included angles are calculated out according to following formulas:

θ

₆₁₂=θ

_A−

θ

_B; and

θ

₆₂₃=θ

_B−

θ

_C.

25. The method of claim 21, wherein when the first, the second, and the third sensing units are at a same side of the middle point, and the third middle-line included angle is larger than second middle-line included angle, and the second middle-line included angle is larger than the first middle-line included angle, the first and the second projection included angles are calculated out according to following formulas:

θ

₆₁₂=θ

_B−

θ

_A; and

θ

₆₂₃=θ

_C−

θ

_B.

26. The method of claim 16, wherein the first predetermined distance is equal to the second predetermined distance;

the predetermined included angle is equal to a sum of three internal angles of a triangle;

the first, the second, and the third auxiliary positioning units are LEDs, and lights emitted by the first, the second, and the third auxiliary positioning units have a same power.

27. The method of claim 26, wherein the measured distance and the measured angle are calculated out according to following formulas:

PW₇₃₂/PW₇₃₁=(D₇₃₁)²/(D_M)²;

PW₇₃₂/PW₇₃₃=(D₇₃₃)²/(D_M)²;

(D₇₃₁)²+(D₇₃₃)²=2×

[(D_A)²+(D_M)²];

(½

)×

D_A×

D₇₃₃×

sin θ

_M=[V×

(V−

D_A)×

(V−

D₇₃₃)×

(V−

D_M)]; and

V=(½

)×

(D_A+D₇₃₃+D_M);

wherein D_M represents the measured distance;

θ

_M represents the measured angle;

D_A represents the first predetermined distance or the second predetermined distance;

D₇₃₁ represents a distance between the first sensing unit and the first auxiliary positioning unit;

D₇₃₃ represents a distance between the third sensing unit and the third auxiliary positioning unit;

V represents a half of a perimeter of a triangle formed by the second auxiliary positioning line, the second projection line, and the third projection lines;

PW₇₃₁ represents a power of a received light of the first sensing unit;

PW₇₃₂ represents a power of a received light of the second sensing unit;

PW₇₃₃ represents a power of a received light of the third sensing unit.

28. The method of claim 16, wherein the measured distance is a distance between the first sensing unit and the first auxiliary positioning unit, a distance between the second sensing unit and the second auxiliary positioning unit, or a distance between the third sensing unit and the third auxiliary positioning unit;

the measured angle is an included angle between a connecting line formed between the second sensing unit and the second auxiliary positioning unit, and the first auxiliary positioning line, a included angle between a connecting line formed between the second sensing unit and the second auxiliary positioning unit, and the second auxiliary positioning line, an included angle between a connecting line formed between the first sensing unit and the first auxiliary positioning unit, and the first auxiliary positioning line, or an included angle between a connecting line formed between the third sensing unit and the third auxiliary positioning unit, and the second auxiliary positioning line.