Distance measuring apparatus, distance measuring method, and computer program product

• US 20080079954A1
• Filed: 11/19/2007
• Published: 04/03/2008
• Est. Priority Date: 05/19/2005
• Status: Active Grant

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Corporation
• Inventors: Miyoshi, Takashi, Iwaki, Hidekazu, Kosaka, Akio
• Granted Patent: US 7,656,508 B2
• Time in Patent Office: Days
• US Class Current: 356/614
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G01S 11/12 using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 13/867 Combination of radar systems with cameras
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders

Abstract

A distance measuring apparatus includes a detecting unit which detects a distance to an object located in a predetermined detection range; an imaging unit which generates an image signal group corresponding to a predetermined imaging field; a calculating unit which calculates the distance to the object located in the imaging field based on the image signal group; and an interpolating unit which either interpolates a detection result by the detecting unit by using a calculation result by the calculating unit, or interpolates the calculation result by the calculating unit by using the detection result by the detecting unit.

Claims

1. A distance measuring apparatus comprising:

a detecting unit which detects a distance to an object located in a predetermined detection range;

an imaging unit which generates an image signal group corresponding to a predetermined imaging field;

a calculating unit which calculates the distance to the object located in the imaging field based on the image signal group; and

an interpolating unit which either interpolates a detection result by the detecting unit by using a calculation result by the calculating unit, or interpolates the calculation result by the calculating unit by using the detection result by the detecting unit.

2. The distance measuring apparatus according to claim 1, wherein the interpolating unit interpolates between detected values by the detecting unit with the calculated values by the calculating unit.

3. The distance measuring apparatus according to claim 2 comprising:

a calculation range setting unit which obtains a predetermined function passing through the detected values, and sets a region through which the predetermined function passes as a calculation range in the calculating unit, wherein

the calculating unit detects an image signal satisfying a predetermined condition out of the image signal group corresponding to the calculation range, and calculates the distance to the object located in the imaging field.

4. The distance measuring apparatus according to claim 3, wherein the predetermined function is a linear function.

5. The distance measuring apparatus according to claim 2, comprising:

a calculation range setting unit which sequentially sets a calculation range in the calculating unit based on the detected value or the calculated value located in the vicinity of an image signal which is to be a calculation target, wherein

the calculating unit detects an image signal satisfying a predetermined condition out of the image signal group corresponding to the calculation range, and calculates the distance to the object located in the imaging field.

6. The distance measuring apparatus according to claim 1, wherein the interpolating unit detects a non-detection point from the detection result by the detecting unit, and outputs as distance information the detection result obtained by complementing the non-detection point with the calculated value by the calculating unit.

7. The distance measuring apparatus according to claim 6, wherein

the interpolating unit instructs the calculating unit on a distance calculation of a region corresponding to the non-detection point, and

the calculating unit performs the distance calculation based on the calculation instruction from the interpolating unit.

8. The distance measuring apparatus according to claim 1, comprising:

a reliability obtaining unit which obtains reliability of a calculated value by the calculating unit, wherein

the interpolating unit outputs distance information in which the calculated value, whose reliability obtained by the reliability obtaining unit does not satisfy evaluation criterion, is replaced with a detected value by the detecting unit corresponding to the calculated value.

9. The distance measuring apparatus according to claim 8, wherein

the interpolating unit sets as the detection range of the detecting unit a range corresponding to the calculated value whose reliability does not satisfy the evaluation criterion, and

the detecting unit detects the distance to the object located in the detection range.

10. The distance measuring apparatus according to claim 1, wherein the interpolating unit generates distance information in which information in the detection range obtained by interpolating between detected values by the detecting unit with calculated values by the calculating unit and information outside the detection range including the calculated values corresponding to the outside of the detection range are combined.

11. The distance measuring apparatus according to claim 10, wherein the interpolating unit generates the distance information by using the previous information outside the detection range until completion of obtaining the information outside the detection range being processed.

12. The distance measuring apparatus according to claim 10, wherein the interpolating unit obtains the information in detection range while the detecting unit obtains the detected value.

13. The distance measuring apparatus according to claim 10, comprising:

a detection range searching unit which searches for a detection range of the detecting unit, wherein

the interpolating unit obtains the information in detection range and the information outside the detection range based on a search result by the detection range searching unit.

14. The distance measuring apparatus according to claim 1, comprising an outline generating unit which generates outline information indicating outline of the object in the imaging field based on a detected value by the detecting unit and a calculated value by the calculating unit.

15. The distance measuring apparatus according to claim 14, comprising:

a judging unit which judges whether the outline information generated by the outline generating unit conforms to another outline information indicating outline obtained based on the image signal group, wherein

the outline generating unit outputs the outline information judged to conform by the judging unit.

16. The distance measuring apparatus according to claim 1, wherein

the imaging unit generates as the image signal group a first image signal group picked up through a first optical path and a second image signal group picked up through a second optical path, and

the calculating unit detects the image signal matched with an arbitrary image signal of the first image signal group from the second image signal group, and calculates the distance to the object located in the imaging field based on an amount of movement of the detected image signal from the arbitrary image signal.

17. The distance measuring apparatus according to claim 1, wherein

the imaging unit includes

a pair of optical systems;

and

a pair of image pickup elements which convert an optical signal output from the pair of optical systems to an electrical signal.

18. The distance measuring apparatus according to claim 1, wherein

the imaging unit includes

a pair of waveguide optical systems;

and

an image pickup element which has imaging regions corresponding respectively to the waveguide optical systems, and converts the optical signal guided by each waveguide optical system into the electrical signal in each imaging region.

19. The distance measuring apparatus according to claim 1, wherein the distance measuring apparatus is mounted on a vehicle.

20. A distance measuring method comprising:

detecting a distance to an object located in a predetermined detection range;

generating an image signal group corresponding to a predetermined imaging field;

calculating the distance to the object located in the imaging field based on the image signal group; and

either interpolating a detection result by the detecting by using a calculation result by the calculating or interpolating the calculation result by using the detection result.

21. A computer program product having a computer readable medium including programmed instructions for measuring distance, wherein the instructions, when executed by a computer, cause the computer to perform:

detecting a distance to an object located in a predetermined detection range;

generating an image signal group corresponding to a predetermined imaging field;

calculating the distance to the object located in the imaging field based on the image signal group; and

either interpolating a detection result by the detecting by using a calculation result by the calculating or interpolating the calculation result by using the detection result.