Scanning optical rangefinder

• US 5,805,275 A
• Filed: 09/29/1995
• Issued: 09/08/1998
• Est. Priority Date: 04/08/1993
• Status: Expired due to Fees

• Current Assignee: Kollmorgen Corporation (Regal Rexnord Corp.)
• Original Assignee: Kollmorgen Corporation (Regal Rexnord Corp.)
• Inventors: Taylor, William H.
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US08/536,630
• Time in Patent Office: 1,075 Days
• Field of Search: 356/4.01, 356/5.01, 356/5.1, 356/3.01-3.15, 180/169, 180/167, 359/202
• US Class Current: 356/3.16
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/46 Indirect determination of position data
• CPC Class Codes: G01S 17/48 Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/88 Lidar systems specially adapted for specific applications
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating
• CPC Class Codes: G02B 26/10 Scanning systems

Abstract

A scanning optical rangefinder including an optical scanner and a light source. The optical scanner includes a rotating scan disc with a circular array of concave reflectors thereon. Mirrors are provided for directing light from the light source towards the concave reflectors on the rotating scan disc and then to direct light from the concave reflectors on the scan disc towards a target. Light received from the target is directed towards the concave reflectors on the scan disc by mirrors along a plurality of channels. A detector adapted to receive light reflected from the concave reflectors is provided for each channel, along with error correction for parallax data from the detector. The light is directed towards the target along a channel laterally displaced from a channel for light received from the target.

Claims

1. A scanning rangefinder, comprising:

a radiation source;

a scanning element;

means for directing radiation from said radiation source towards said scanning element;

means for directing radiation reflected from said scanning element towards a target;

means for directing radiation from said target towards said scanning element along a plurality of channels;

a detector adapted to receive radiation reflected from said scanning element along each of said channels; and

means for error correction for parallax data from said detector;

wherein radiation is directed along a channel laterally displaced from a channel receiving radiation.

2. A scanning rangefinder according to claim 1, wherein said scanning element is a CVROS scanner.

3. A scanning rangefinder according to claim 1, wherein said scanning element is a polygon scanner.

4. A scanning rangefinder according to claim 1, wherein said scanning element is a plurality of oscillating mirrors.

5. A scanning rangefinder according to claim 1, further comprising means for vertically scanning a field of view.

6. A scanning rangefinder according to claim 5, wherein said means for vertically scanning further comprises at least one rotatable mirror.

7. A scanning rangefinder according to claim 5, wherein said means for vertically scanning further comprises means for translating a housing of the scanning rangefinder.

8. A scanning rangefinder according to claim 1, wherein said radiation source is a laser.

9. A scanning rangefinder according to claim 8, wherein said laser is a GaAlAs laser diode.

10. A scanning rangefinder according to claim 1, wherein said radiation source illuminates each pixel in a field of view.

11. A scanning rangefinder according to claim 1, wherein the scanning rangefinder has at least two optical levels.

12. A scanning rangefinder according to claim 1, wherein said means for directing radiation from said target directs radiation along two channels.

13. A scanning rangefinder according to claim 12, wherein radiation directed from said radiation source to said target travels along one of the same channels as radiation directed from said target to said detector.

14. A scanning rangefinder according to claim 1, wherein said detector adapted to receive radiation reflected from said scanning element along each of said channels further comprises a single element detector and a detector array.

15. A scanning rangefinder according to claim 1, wherein said means for directing radiation from said radiation source further comprises at least one mirror.

16. A scanning rangefinder according to claim 1, wherein said means for directing radiation reflected from said scanning element further comprises at least one mirror.

17. A scanning rangefinder according to claim 1, wherein said means for directing radiation from said target further comprises at least one mirror.

18. A scanning rangefinder according to any one of claims 15, 16 or 17, wherein said at least one mirror is integrally formed with a housing of the scanning rangefinder.

19. A scanning rangefinder according to claim 1, further comprising a signal processor for determining target range and lateral position from a signal from said detector.

20. A scanning rangefinder according to claim 19, further comprising a signal processor for determining target reflectivity from a signal from said detector.

21. A scanning rangefinder according to claim 19, further comprising a signal processor for target imaging.

22. A scanning rangefinder according to claim 1, further comprising a signal processor for establishing a signal threshold for signals from said detector and for rejection of extraneous signals from said detector.

23. A scanning rangefinder according to claim 1, further comprising a signal processor for centroid location on said detector.

42. An optical scanner according to claim 20, further comprising a signal processor for establishing a signal threshold for signals from said detector and for rejection of extraneous signals from said detector.

24. An optical scanner, comprising:

a light source;

a rotating scan disc including a circular array of scanning element on a planar surface thereof;

means for directing light from said light source towards said scanning element;

means for directing light reflected from said scanning element towards a target;

means for directing light from said target towards said scanning element along a plurality of channels;

a detector adapted to receive light reflected from said scanning element along each of said channels; and

means for error correction for parallax data from said detector;

wherein radiation is directed along a channel laterally displaced from a channel receiving radiation.

25. An optical scanner according to claim 24, further comprising means for vertically scanning a field of view.

26. An optical scanner according to claim 25, wherein said means for vertically scanning further comprises at least one rotatable mirror.

27. An optical scanner according to claim 25, wherein said means for vertically scanning further comprises means for translating a housing of the optical scanner.

28. An optical scanner according to claim 24, wherein said light source is a laser.

29. An optical scanner according to claim 28, wherein said laser is a GaAlAs laser diode.

30. An optical scanner according to claim 24, wherein said light source illuminates each pixel in a field of view.

31. An optical scanner according to claim 24, wherein the optical scanner has at least two optical levels.

32. An optical scanner according to claim 24, wherein said means for directing light from said target directs light along two channels.

33. An optical scanner according to claim 32, wherein light directed from said light source to said target travels along one of the same channels as light directed from said target to said detector.

34. An optical scanner according to claim 24, wherein said detector adapted to receive light reflected from said scanning element along each of said channels further comprises a single element detector and a detector array.

35. An optical scanner according to claim 24, wherein said means for directing light from said light source further comprises at least one mirror.

36. An optical scanner according to claim 24, wherein said means for directing light reflected from said scanning element further comprises at least one mirror.

37. An optical scanner according to claim 24, wherein said means for directing light from said target further comprises at least one mirror.

38. An optical scanner according to any one of claims 35, 36 or 37, wherein said at least one mirror is integrally formed with a housing of the optical scanner.

39. An optical scanner according to claim 24, further comprising a signal processor for determining target range and lateral position from a signal from said detector.

40. An optical scanner according to claim 39, further comprising a signal processor for determining target reflectivity from a signal from said detector.

41. An optical scanner according to claim 39, further comprising a signal processor for target imaging.

43. An optical scanner according to claim 24, further comprising a signal processor for centroid location on said detector.

44. A collision avoidance system, comprising:

light source;

a rotating scan disc including a circular array of scanning element on a planar surface thereof;

means for directing radiation from said radiation source towards said scanning element;

means for directing radiation reflected from said scanning element towards a target;

means for directing radiation from said target towards said scanning element along a plurality of channels;

a detector adapted to receive radiation reflected from said scanning element along each of said channels; and

means for error correction for parallax data from said detector;

wherein said light source, said rotating scan disc, said means for directing light from said light source, said means for directing light reflected from said concave reflectors, said means for directing light from said target and said detector are mounted in a vehicle; and

wherein radiation is directed along a channel laterally displaced from a channel receiving radiation.

45. A collision avoidance system according to claim 44, further comprising means for vertically scanning a field of view.

46. A collision avoidance system according to claim 45, wherein said means for vertically scanning further comprises at least one rotatable mirror.

47. A collision avoidance system according to claim 45, wherein said means for vertically scanning further comprises means for translating a housing of the collision avoidance system.

48. A collision avoidance system according to claim 44, wherein said light source is a laser.

49. A collision avoidance system according to claim 48, wherein said laser is a GaAlAs laser diode.

50. A collision avoidance system according to claim 44, wherein the collision avoidance system has at least two optical levels.

51. A collision avoidance system according to claim 44, wherein said means for directing light from said target directs light along two channels.

52. A collision avoidance system according to claim 51, wherein light directed from said light source to said target travels along one of the same channels as light directed from said target to said detector.

53. A collision avoidance system according to claim 44, wherein said detector adapted to receive light reflected from said scanning element along each of said channels further comprises a single element detector and a detector array.

54. A collision avoidance system according to claim 44, wherein said means for directing light from said light source further comprises at least one mirror.

55. A collision avoidance system according to claim 44, wherein said means for directing light reflected from said scanning element further comprises at least one mirror.

56. A collision avoidance system according to claim 44, wherein said means for directing light from said target further comprise at least one mirror.

57. A collision avoidance system according to any one of claims 54, 55 or 56, wherein said at least one mirror is integrally formed with a housing of the collision avoidance system.

58. A collision avoidance system according to claim 44, further comprising a signal processor for determining target range and lateral position from a signal from said detector.

59. A collision avoidance system according to claim 58, further comprising a signal processor means for determining target reflectivity from a signal from said detector.

60. A collision avoidance system according to claim 58, further comprising a signal processor for target imaging.

61. A collision avoidance system according to claim 44, further comprising a signal processor for establishing a signal threshold for signals from said detector and for rejection of extraneous signals from said detector.

62. A collision avoidance system according to claim 44, further comprising a signal processor for centroid location on said detector.

63. A collision avoidance system according to any one of claims 59, 60, 61 or 62 wherein information from said detector is processed by a computer in said vehicle.

64. A collision avoidance system according to claim 44, wherein said means for directing light towards a target and said means for directing light from said target are mounted on the centerline of said vehicle.

65. A method of optical scanning, comprising the steps of:

directing light from a light source towards a concave reflector on a rotating scan disc;

directing light reflected from said concave reflector towards a target;

directing light from said target towards scanning element on said scan disc along a plurality of channels;

detecting light reflected from said scanning element along each of said channels; and

correcting errors in parallax data from detected light;

wherein radiation is directed along a channel laterally displaced from a channel receiving radiation.

66. The method of optical scanning according to claim 65, further comprising the step of vertically scanning a field of view.

67. The method of optical scanning according to claim 65, further comprising the step of providing a laser as said light source.

68. The method of optical scanning according to claim 65, further comprising the step of directing light from said target along at least two optical levels.

69. The method of optical scanning according to claim 65, further comprising the step of directing light from said target along two channels.

70. The method of optical scanning according to claim 69, further comprising the step of directing light from said light source to said target and at least some light from said target along the same channel.

71. The method optical scanning according to claim 65, further comprising the step of using mirrors integrally formed with a housing to direct light.

72. The method of optical scanning according to claim 65, further comprising the step of determining the range and lateral position of said target.

73. The method of optical scanning according to claim 72, further comprising the step of determining the reflectivity of said target.

74. The method of optical scanning according to claim 72, further comprising the step of imaging said target.

75. The method of optical scanning according to claim 65, further comprising the step of locating the centroid of light reflected from said target.

76. The method of optical scanning according to any one of claims 72, 73, 74 or 75, further comprising the step of processing information from said detected light by a computer in a vehicle.