Four sensor system for wheel alignment

• US 6,181,993 B1
• Filed: 07/02/1996
• Issued: 01/30/2001
• Est. Priority Date: 10/16/1992
• Status: Expired due to Fees

• Current Assignee: Snap-On Technologies Incorporated (Snap-On Incorporated)
• Original Assignee: Snap-On Technologies Incorporated (Snap-On Incorporated)
• Inventors: de Bellefeuille, Jean Oliver Wilfrid Jr., Dale, James L. Jr., Poe, Richard J.
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Hernandez, Olga
• Application Number:
  US08/674,366
• Time in Patent Office: 1,673 Days
• Field of Search: 332/031.8, 332/88, 364/559, 364/424.01, 364/424.03, 356/138, 356/139.09, 356/155
• US Class Current: 701/29
• CPC Class Codes: G01B 11/275 for testing wheel alignment
• CPC Class Codes: G01B 11/2755 using photoelectric detection means
• CPC Class Codes: G01B 2210/26 Algorithms, instructions, databases, computerized methods and graphical user interfaces employed by a user in conjunction with the wheel aligner
• CPC Class Codes: G01B 2210/283 Beam projectors and related sensors
• CPC Class Codes: G01M 17/06 Steering behaviour; Rolling behaviour

Abstract

A four sensor wheel aligner has a single omnidirectional angle sensor mounted on each of four vehicle support wheels. Each sensor is in optical communication with the other sensors. Data is produced from which toe, camber, caster and steering axis inclination angles are computed. No reference is made to vertical. Redundant data sets are produced which provide system reliability and error tracking features and maximum accuracy from available data sets. Frame distortion measurements are made to facilitate collision repair in coordination with wheel alignment.

Claims

1. A wheel alignment system for vehicles comprising at least four vehicle support wheels which comprises:

single means for angle measurement mounted in predetermined relationship to a wheel plane of each of the four vehicle support wheels for collectively providing wheel angle indicative output signals in redundant signal sets, any one of said signal sets containing data sufficient to obtain four wheel alignment angles;

said single means for angle measurement comprising

omnidirectional beam projection means mounted on each of a first two support wheels for projecting a plurality of beams in known directions with respect to the wheel plane, and

directional beam reception means mounted on a second two support wheels for providing receiver output signal indicative of direction of received beams relative to the wheel plane of respective ones of said second two support wheels and of identity of the direction of projection of received beams relative to the wheel plane of respective ones of said first two support wheels; and

means in communication with said single means for receiving and processing said redundant signal sets and for computing alignment angles for the support wheels.

2. A wheel alignment system as in claim 1 wherein said means for receiving and processing comprises

means for detecting the highest intensity received beams from said receiver output signal,

means for selecting a plurality of said highest intensity beam receiver output signals corresponding to ones of said first two support wheels,

means receiving said selected plurality of receiver output signals and for identifying the angles of projection of each of said plurality of highest intensity beams, and

means for combining said identified angles of projection from each of said first two support wheels to provide indication of projection angle relative to the plane of each of said first two wheels, of a beam extending directly from said omnidirectional beam projection means to said directional beam reception means.

3. A wheel alignment system for vehicles comprising at least four support wheels which comprises:

single means for angle measurement mounted in predetermined relationship to a wheel plane of each of the four vehicle support wheels for collectively providing wheel angle indicative output signals;

said single means for angle measurement comprising

omnidirectional beam projection means mounted on a first support wheel for projecting a plurality of beams in known directions with respect to the wheel plane, and

directional beam reception means mounted on each of the other three support wheels for providing receiver output signals indicative of direction of received ones of said plurality of beams relative to the wheel plane of respective ones of said other three support wheels and of identity of the direction of projection of received ones of said plurality of beams relative to the wheel plane of said first support wheel; and

means in communication with said single means for receiving and processing said output signals and for computing alignment angles for the support wheels.

4. A wheel alignment system as in claim 3 wherein said means for receiving and processing comprises

means for detecting highest intensity received beams from said receiver output signals,

means for selecting a plurality of said highest intensity beam receiver output signals,

means for receiving said selected receiver output signals and for identifying the angle of projection of each of said plurality of highest intensity beams, and

means for combining said identified angles of projection to provide indication of projection angle relative to the plane of said first wheel of a beam extending directly from said omnidirectional beam projection means to each of said directional beam reception means.

5. A wheel alignment system for vehicles having at least four wheels, each wheel including a reference wheel plane substantially perpendicular to the axis of rotation of the wheel, the wheel alignment system comprising:

means mounted relative to the wheel plane of a first wheel for projecting a plurality of beams in known directions with respect to the wheel plane and for generating signals indicative of the angles of projection of the beams;

means mounted relative to the wheel plane of each wheel other than the first wheel for detecting the beams projected by the projecting means and for generating a signal indicative of the receipt of a projected beam; and

means in communication with the projecting and the detecting means for determining the angle in the toe plane of the first wheel with respect to the other wheels from the signals generated by the projecting and the detecting means.

6. The wheel alignment system of claim 5 further comprising:

means mounted relative to the wheel plane of each wheel for projecting a plurality of beams in known directions with respect to the wheel plane and for generating signals indicative of the angles of projection of the beams;

means mounted relative to the wheel plane of each wheel for detecting the beams projected by the projecting means mounted to each of the other wheels and for generating signals indicative of the receipt of the projected beams; and

means in communication with the projecting and the detecting means for determining the angles in the toe plane of each wheel with respect to the other wheels from the signals generated by the projecting and the detecting means and for calculating alignment values for the vehicle from the determined angles.

7. The wheel alignment system of claim 6 further comprising:

receiver means positioned a known distance from the projecting means mounted to a first wheel for receiving the beams projected by the projecting means mounted to a second wheel;

means in communication with the projecting means and the receiver means for determining the angle between the second wheel and the receiver means; and

means for determining the distance between the first and second wheels from the known distance, the determined angle between the second wheel and the first wheel and the determined angle between the second wheel and the receiver means.

8. The wheel alignment system of claim 7, further comprising:

reflective means mountable to at least a first vehicle component;

wherein the beams projected by the projecting means mounted to the first and second wheels are reflected back to the first and second wheels by the reflective means and received by the detecting means mounted to the respective wheels;

means in communication with the projecting means and the detecting means for determining the angles between the first and second wheels and the reflective means; and

means for determining the relative position of the vehicle component with respect to the first and second wheels from the determined angles and the distance between the first and second wheels.

9. A wheel alignment system for vehicles having at least four wheels, each wheel including a reference wheel plane substantially perpendicular to the axis of rotation of the wheel, the wheel alignment system comprising:

means mounted relative to the wheel plane of a first wheel for projecting a plurality of beams in known directions with respect to the wheel plane and for generating signals indicative of the angles of projection of the beams;

means mounted relative to the wheel plane of a second wheel for detecting the beams projected by the projecting means and for generating a signal indicative of the receipt of a projected beam; and

means in communication with the projecting and the detecting means for determining a vertical angle of the first wheel with respect to the second wheel from the signals generated by the projecting and the detecting means.

10. The wheel alignment system of claim 9, further comprising:

means mounted relative to the wheel plane of the second wheel for projecting a plurality of beams in known directions with respect to the wheel plane and for generating signals indicative of the angles of projection of the beams;

means mounted relative to the wheel plane of the first wheel for detecting the beams projected by the projecting means mounted to the second wheel and for generating a signal indicative of the receipt of a projected beam; and

means in communication with the projecting and the detecting means for determining the vertical angles of the first and second wheels with respect to the second and first wheels, respectively, from the signals generated by the projecting and the detecting means.

11. The wheel alignment system of claim 10, further comprising:

first and second receiver means mounted a known distance apart on a support surface for the wheels;

means in communication with the projecting means mounted on the first wheel and the receiver means for determining the angles between the projecting means and each receiver means;

means for computing the height of the projecting means above the support surface from the known distance and the determined angles between the projecting means and each receiver means.

12. The wheel alignment system of claim 10, further comprising:

first and second receiver means mounted to respective vehicle components;

means in communication with the projecting means mounted on the first and second wheels and the receiver means for determining the angles between each projecting means and each receiver means;

means for computing the vertical distance between the receiver means from the determined vertical angles between the first and second wheels and the determined angles between each projecting means and each receiver means.

13. A wheel alignment system for vehicles comprising at least four support wheels which comprises:

single means for angle measurement mounted in predetermined relationship to a wheel plane of each of the support wheels for collectively providing wheel angle indicative output signals in redundant signal sets, any of said signal sets containing data sufficient to obtain four wheel alignment angles;

said single means for angle measurement comprising

omnidirectional beam projection means for projecting a plurality of beams in known directions with respect to the wheel plane mounted on each of a first three support wheels, and

directional beam reception means mounted on a fourth support wheel and providing a receiver output signal indicative of direction of received beams relative to the wheel plane of the fourth wheel and of identity of the direction of projection of received beams relative to the wheel plane of respective ones of said first three support wheels; and

means in communication with said single means for receiving and processing said redundant signal sets and for computing alignment angles for the support wheels.

14. A wheel alignment system as in claim 13 wherein said means for receiving and processing comprises

means for detecting the highest intensity received beams from said receiver output signals,

means for selecting a plurality of said highest intensity beam receiver output signals corresponding to ones of said first three support wheels,

means for receiving said selected plurality of receiver output signals and for identifying the angles of projection of said plurality of highest intensity beams, and

means for combining said identified angles of projection from each of said first three support wheels to provide indication of angle of projection relative to the plane of each of said first three wheels of a beam extending directly from said omnidirectional beam projection means to said directional beam reception means.

15. A vehicle wheel alignment system for use on level or non level vehicle support surfaces to align wheels on a vehicle having a vehicle frame and at least four support wheels each having a defined wheel plane, comprising:

omnidirectional beam projection means mounted on each support wheel in known orientation with respect to the wheel plane for projecting a plurality of beams in known directions with respect to the wheel plane;

beam reception means mounted in known position on each support wheel providing beam received signals when impinged by a projected beam;

means for receiving said beam received signals and for determining spatial angles between a wheel plane on which said omnidirectional beam projection means is mounted and a beam projected from said omnidirectional beam projection means; and

means for combining the determined spatial angles for obtaining wheel alignment angles relative to the defined wheel planes for the four support wheels.

16. A vehicle wheel alignment system as in claim 15 wherein at least two of the support wheels are steerable and wherein said beam received signals resulting from impingement of projected beams from the steerable wheels provide roll angles at known steering angles, said means for combining receiving said roll angles and providing caster angles for the steerable support wheels.

17. A vehicle wheel alignment system as in claim 15 wherein at least two of the support wheels are steerable and wherein said beam received signals resulting from impingement by projected beams from the steerable wheels provide pitch angles at known steering angles, said means for combining receiving said pitch angles and providing steering axis inclination angles relative to the defined wheel planes for the steerable support wheels.

18. A vehicle wheel alignment system as in claim 15 comprising

means mounted in at least two positions on the vehicle frame in optical communication with said omnidirectional beam projection means, whereby communication between ones of said mounted means and any two of said beam projection means provides vehicle frame coordinate position identification at said two positions, whereby frame collision damage is assessable.

19. A vehicle wheel alignment system as in claim 15 comprising

means mounted on the non-level support surface for receiving projected beams from said omnidirectional beam projection means, whereby communication between said support surface mounted means and any two of said beam projection means provides vehicle ride height information.

20. A vehicle wheel alignment system as in claim 15 wherein the vehicle has a chassis and a suspension, comprising

means mounted at points on the chassis and the suspension separated by a ride height distance, said mounted means being in optical communication with said omnidirectional beam projection means, whereby communication with any two of said beam projection means provides vehicle ride height information.

21. A vehicle wheel alignment system as in claim 15 wherein said determined spatial angles comprise redundant angle sets and wherein said means for combining comprises

means for prioritizing said angle sets in order of potential measurement accuracy,

means for selecting the highest priority angle set available, and

means for processing said highest priority angle set available to obtain wheel alignment angles relative to defined wheel planes.

22. A vehicle wheel alignment system as in claim 21 wherein said means for processing comprises

means for receiving and processing lower accuracy priority angle sets whereby redundant alignment angles are obtained.

23. A wheel alignment system for vehicles having a vehicle frame, a vehicle body and at least four vehicle support wheels, each support wheel having a wheel plane for alignment reference, said wheel alignment system comprising:

single means for angle measurement mounted in predetermined relationship to the wheel plane of each of the four vehicle support wheels for collectively providing wheel angle indicative output signals in redundant signal sets, any one of said signal sets containing data sufficient to obtain four wheel alignment angles;

said single means for angle measurement comprising omnidirectional beam projection means mounted on each support wheel for projecting a plurality of optical energy beams in known directions with respect to the wheel plane, and non-directional beam reception means mounted on each support wheel, said reception means on each support wheel being in optical communication with said beam projection means on other support wheels and providing receiver output signals indicative of beam reception; and

means in communication with said single means for receiving and processing said receiver output signals for providing said redundant signal sets and for computing alignment angles for the support wheels.

24. A wheel alignment system as in claim 23 wherein said wheel angle indicative output signal sets comprise signal sets containing data sufficient to obtain toe and camber angles.

25. A wheel alignment system as in claim 23 wherein at least two of said vehicle support wheels are steerable and wherein said single means for angle measurement mounted on steerable support wheels provides roll signals at known steering angles, and means for receiving said roll signals and for providing caster angle signals for said steerable support wheels.

26. A wheel alignment system as in claim 23 wherein at least two of said vehicle support wheels are steerable and wherein said single means for angle measurement mounted on steerable support wheels provides pitch signals at known steering angles, and means for receiving said pitch signals and for providing steering axis inclination angle signals for said steerable support wheels.

27. A wheel alignment system as in claim 23 wherein said means for receiving and processing comprises

means for detecting highest intensity beams from said receiver output signal provided by said beam reception means,

means for selecting a plurality of said highest intensity beam received output signals,

means receiving said receiver output signals for determining angles of projection of each of said plurality of highest intensity beams, and

means for combining said determined angles of projection to provide indication of projection angle of a beam extending directly from said omnidirectional beam projection means to said non-directional beam reception means.

28. A wheel alignment system as in claim 23 wherein said omnidirectional beam projection means comprises

a rotation motor,

an encoder coupled to said rotation motor,

reflector means coupled to said rotation motor, and

energy beam emitting means for directing an energy beam toward said reflector means so that at least two rotating reflected beams are provided therefrom at known projection angles relative to the plane of each vehicle support wheel.

29. A wheel alignment system as in claim 23 comprising

at least two points on a member on the vehicle frame in optical communication with said omnidirectional beam projection means, whereby communication between said at least two points and any two of said beam projection means provides vehicle frame coordinate position identification at said two points, so that frame collision damage is assessable.

30. A wheel alignment system as in claim 23 comprising beam reception means mounted to predetermined points on the vehicle body in optical communication with said omnidirectional beam projection means, whereby communication between said beam reception means and any two of said beam projection means provides known body point coordinate position identification for vehicle frame collision damage assessment.

31. A wheel alignment system as in claim 23 wherein there is a distance between each pair of the four vehicle support wheels, comprising

means for scaling the distance between each pair of support wheels, whereby relative positions between wheels are determined.

32. A wheel alignment system as in claim 23 wherein said means for receiving and processing said redundant signal sets comprises

means for prioritizing said signal sets in order of potential measurement accuracy,

means for selecting the highest accuracy priority signal set available for signal processing,

means for processing said highest priority signal set available to obtain said alignment angles for the support wheels.

33. A wheel alignment system as in claim 32 wherein said means for processing comprises means for receiving additional signal sets whereby redundant alignment angles for the support wheels are obtained.

34. A wheel alignment system as in claim 23 wherein said omnidirectional beam projection means comprises a plurality of energy beam emitting means for producing a plurality of energy beams having known beam spread intensity characteristics,

means for mounting said plurality of energy beam emitting means so that said beams are projected in distinct known spatial angles relative to the plane of the vehicle support wheel, and

means for exciting said plurality of energy beam emitting means in predetermined sequence and for providing emission signals, corresponding thereto to said means for determining angles indicative of individual beam excitation.

35. A wheel alignment system as in claim 34 wherein said plurality of energy beam emitting means comprises ten light emitters, wherein five are mounted to project beams at substantially 27°

north spatial latitude and five are mounted to project beams at substantially 27°

south spatial latitude, and wherein each emitter is mounted to project beams at substantially 36°

spatial longitude separation.

36. A wheel alignment system as in claim 23 wherein the support wheels support a vehicle chassis, comprising means in communication with said single means for angle measurement for determining the vehicle chassis centerline position relative to the support wheels.

37. A wheel alignment system as in claim 36 wherein said means for determining the vehicle chassis centerline comprises retro reflector means mounted in known position on the vehicle chassis in visual communication with at least two of said single angle measurement means.

38. A wheel alignment system for a vehicle having a vehicle frame, a vehicle body and at least four support wheels, each support wheel having a wheel plane for wheel alignment angle reference, said wheel alignment system comprising:

single means for angle measurement mounted on each support wheel in known orientation with respect to the plane of the wheel for determining spatial angles relating to the toe and camber of the plane of the wheel on which the single means is mounted with respect to a projected energy beam extending between the single means and a single means mounted on at least one other wheel, and for providing angle indicative signals corresponding thereto; and

means for receiving and processing said angle indicative signals for providing signals indicative of toe and camber alignment angles between the wheel planes of the support wheels.

39. A wheel alignment system as in claim 38 wherein said projected beam angle indicative signals comprise redundant signal sets and wherein said means for receiving and processing comprises

means for prioritizing said signal sets in order of potential measurement accuracy,

means for selecting the highest accuracy priority signal set available for signal processing, and

means for processing said highest priority signal set available to obtain said alignment angles for the support wheels.

40. A wheel alignment system as in claim 39 wherein said means for processing comprises

means for receiving and processing lower accuracy priority signal sets whereby redundant alignment angles for the support wheels are obtained.

41. A wheel alignment system as in claim 38 wherein at least two of the support wheels are steerable and wherein said single means for angle measurement mounted on steerable support wheels provides roll signals at known steering angles, and means for receiving said roll signals and for providing caster angle signals for the steerable support wheels.

42. A wheel alignment system as in claim 38 wherein at least two of the support wheels are steerable and wherein said single means for angle measurement mounted on steerable support wheels provides pitch signals at known steering angles, and means for receiving said pitch signals and for providing steering axis inclination angles for the steerable support wheels.

43. A wheel alignment system as in claim 38 wherein a distance exists between wheels in each pair of support wheels, comprising means for scaling the distance between each pair of support wheels, whereby relative positions between the support wheels may be determined.

44. A wheel alignment system as in claim 38 comprising

means mounted in at least two positions to the vehicle frame in optical communication with at least two of said single omnidirectional means for angle measurement, whereby said at least two means for angle measurement provide vehicle frame coordinate position identification at said at least two positions so that collision damage is assessable.

45. A wheel alignment system as in claim 38 comprising

beam reception means-mounted to predetermined points on the vehicle body in optical communication with said single omnidirectional means for angle measurement, whereby communication with any two of said means for angle measurement provides known vehicle body point coordinate position in identification for frame collision damage assessment.

46. A wheel alignment system as in claim 38 wherein the vehicle support wheels support a vehicle chassis, comprising means in communication with said single means for angle measurement for determining vehicle chassis centerline position relative to the support wheels.

47. A wheel alignment system as in claim 46 wherein said means for determining vehicle chassis centerline comprises retro reflector means mounted in known positions on said chassis in visual communication with at least two of said single means for angle measurement.

48. A wheel alignment system as in claim 38 wherein said single means for angle measurement comprises

omnidirectional beam projection means mounted on a first two support wheels, and

directional beam reception means mounted on a second two support wheels and providing receiver output signal indicative of direction of received beams relative to the wheel plane of respective ones of said second two support wheels.

49. A wheel alignment system as in claim 43 wherein said means for receiving and processing comprises

means for detecting the highest intensity received beams from said receiver output signals,

means for selecting a plurality of said highest intensity beam receiver output signals corresponding to ones of said first two support wheels,

means receiving said selected plurality of receiver output signals and for identifying the angles of projection of said plurality of highest intensity beams, and

means for combining said identified angles of projection from each of said first two support wheels to provide indication of angle of projection relative to the plane of each of said first two wheels of a beam extending directly from said omnidirectional beam projection means to said directional beam reception means.

50. A wheel alignment system as in claim 38 wherein said single angle measurement means comprises

omnidirectional beam projection means mounted on a first support wheel, and

directional beam reception means mounted on each of the other three support wheels providing receiver output signal indicative of direction of received beams relative to the wheel planes of respective ones of said other three support wheels.

51. A wheel alignment system as in claim 50 wherein said means for receiving and processing comprises

means for detecting highest intensity received beams from said receiver output signals,

means for selecting a plurality of said highest intensity receiver output signals,

means for receiving said selected highest intensity receiver output signals and for identifying the angle of projection of each of said plurality of highest intensity beams, and

means for combining said identified angles of projection to provide indication of projection angle relative to the plane of said first wheel of a beam extending directly from said omnidirectional beam projection means to each of said directional beam reception means.

52. A wheel alignment system as in claim 38 wherein said single means for angle measurement comprises

omnidirectional beam projection means mounted on a first three support wheels, and

directional beam reception means mounted on a fourth support wheel and providing receiver output signal indicative of direction of received beams relative to the wheel plane of said fourth wheel.

53. A wheel alignment system as in claim 52 wherein said means for receiving and processing comprises

means for detecting the highest intensity received beams from said receiver output signals,

means for selecting a plurality of said highest intensity receiver output signals corresponding to ones of said first three support wheels,

means receiving said selected plurality of receiver output signals and for identifying the angles of projection of said plurality of highest intensity beams, and

means for combining said identified angles of projection from each of said first three support wheels to provide indication of angle of projection relative to the plane of each of said first three wheels of a beam extending directly from said omnidirectional beam projection means to said directional beam reception means.

54. A wheel alignment system as in claim 38 wherein said single means for angle measurement comprises

omnidirectional beam projection means mounted on each support wheel, and

non-directional beam reception means mounted on each support wheel, said non-directional beam reception means on each support wheel being in optical communication with said beam projection means mounted on other-support wheels and providing received output signal indicative of beam reception.

55. A wheel alignment system as in claim 54 wherein said omnidirectional beam projection means comprises

a rotation motor,

an encoder coupled to said rotation motor,

reflector means coupled to said rotation motor, and

energy beam emitting means for directing an energy beam toward said reflector means so that at least two rotating reflected beams are provided therefrom at known projection angles relative to the plane of the vehicle support wheel.

56. A wheel alignment system as in claim 54 wherein said means for receiving and processing comprises

means for detecting highest intensity beams from said receiver output signal provided by said beam reception means,

means for selecting a plurality of said highest intensity beam receiver output signals corresponding to ones of said support wheels,

means receiving said receiver output signals for determining angles of projection of each of said plurality of highest intensity beams, and

means for combining said determined angles of projection from each of said support wheels to provide indication of projection angle of a beam extending directly from said omnidirectional beam projection means to said non-directional beam reception means.

57. A wheel alignment system as in claim 56 wherein said omnidirectional beam projection means comprises

a plurality of energy beam emitting means for producing a plurality of energy beams having known beam spread characteristics,

means for mounting said plurality of energy beam emitting means so that said beams are projected at known spatial angles relative to the plane of the vehicle support wheel, and

means for exciting said plurality of energy beam emitting means in predetermined sequence and for providing emission signals corresponding to individual beam excitation to said means for determining angles.

58. A wheel alignment system as in claim 57 wherein said plurality of energy beam emitting means comprises ten light emitters, wherein five light emitters are mounted to project beams at substantially 27°

north spatial latitude, and five light emitters are mounted to project beams at substantially 27°

south spatial latitude, and wherein each emitter is mounted to project beams at substantially 36°

spatial longitude separation.

59. A wheel alignment system for a vehicle having a chassis, a vehicle body and at least four support wheels, each support wheel having a wheel plane for wheel alignment reference, said wheel alignment system comprising:

angle measurement means mounted on each wheel in predetermined relationship with the plane of the wheel for providing wheel angle indicative output signals in redundant signal sets, any one of said sets containing data sufficient to obtain desired wheel alignment angles,

means for prioritizing said signal sets in the order of potential wheel alignment angle accuracy;

means for selecting the highest accuracy priority signal set available, and

means for processing said highest accuracy signal set available to obtain said desired wheel alignment angles.

60. A wheel alignment system as in claim 59 wherein said means for processing comprises means for receiving additional signal sets, whereby redundant alignment angles for the support wheels are obtained.

61. A wheel alignment system as in claim 59 wherein said means for processing comprises means for receiving and processing lower accuracy priority signal sets to obtain redundant alignment angles for the support wheels.

62. A wheel alignment system as in claim 59 wherein pairs of the support wheels are spaced apart by a distance, comprising means for scaling the distance between pairs of the support wheels, whereby relative positions between wheels are determined.

63. A wheel alignment system as in claim 59 wherein the vehicle has a frame, comprising

means mounted in selected positions to the vehicle frame in visual communication with at least two of said angle measurement means, whereby communication between said means mounted in selected positions on the frame and any two of said angle measurement means provides vehicle frame coordinate position identification at the selected positions so that frame collision damage is assessable.

64. A wheel alignment system as in claim 59 comprising

means mounted on predetermined location points on the vehicle body, said location points being in communication with said angle measurement means and providing spatial angle measurement signals for the direction extending therebetween, whereby communication between said means mounted on predetermined location points and any two of said angle measurement means provides body point coordinate position identification for frame collision damage assessment.

65. A wheel alignment system as in claim 59 wherein said angle measurement means comprises omnidirectional beam projection means mounted on a first two support wheels, and directional beam reception means mounted on a second two support wheels and providing receiver output indicative of direction of received beams relative to the wheel plane of respective ones of said second two support wheels.

66. A wheel alignment system as in claim 65 wherein said means for processing comprises means for detecting highest intensity received beams from said receiver output and providing receiver output indicative thereof, means for selecting a plurality of said highest intensity beam receiver outputs corresponding to received beams at ones of said first two support wheels, means for receiving said selected plurality of receiver output signals and for determining the angles of projection of said plurality of highest intensity beams, and means for combining said determined angles of projection from each of said first two support wheels to provide indication of angle of projection of a beam extending directly from said omnidirectional beam projection means to said directional beam reception means.

67. A wheel alignment system as in claim 59 wherein said angle measurement means comprises omnidirectional beam projection means mounted on a first support wheel, and directional beam reception means mounted on each of the other three support wheels providing receiver output signal indicative of direction of received beams relative to the wheel planes of respective ones of said other three support wheels.

68. A wheel alignment system as in claim 67 wherein said means for processing comprises means for detecting highest intensity received beams from said receiver output signals, means for selecting a plurality of said receiver output signals corresponding to said highest intensity received beams, means for receiving said selected plurality of receiver output signals and for identifying the angle of projection of each of said highest intensity received beams, and means for combining said identified angles of projection to provide indication of projection angle relative to the plane of said first wheel of a beam extending directly from said omnidirectional beam projection means to each of said direction beam reception means.

69. A wheel alignment system as in claim 59 wherein said angle measurement means comprises

omnidirectional beam projection means mounted on a first three support wheels, and

directional beam reception means mounted on a fourth support wheel and providing receiver output signals indicative of direction of received beams relative to the wheel plane of said fourth wheel.

70. A wheel alignment system as in claim 69 wherein said means for receiving and processing comprises

means for detecting the highest intensity received beams and for providing corresponding highest intensity receiver output signals,

means for receiving said highest intensity receiver output signals and for identifying the angles of projection of said highest intensity received beams, and

means for combining said identified angles of projection from each of said first three support wheels to provide indication of angle of projection relative to the plane of each of said first three wheels of a beam extending directly from said omnidirectional beam projection means to said directional beam reception means.

71. A wheel alignment system as in claim 59 comprising means mounted in known position on the chassis in visual communication with at least two of said angle measurement means for determining a centerline position for the chassis relative to the support wheels.

72. A wheel alignment system as in claim 71 wherein said means for determining chassis centerline comprises retro reflector means.

73. A wheel alignment system as in claim 59 wherein said angle measurement means comprises single omnidirectional angle measurement means.

74. A wheel alignment system as in claim 73 wherein at least two of said vehicle support wheels are steerable and wherein said omnidirectional angle measurement means mounted on steerable support wheels provides roll signals at known steering angles, and means for receiving said roll signals and for providing caster angle signals for said steerable support wheels.

75. A wheel alignment system as in claim 73 wherein at least two of said vehicle support wheels are steerable and wherein said omnidirectional angle measurement means mounted on steerable support wheels provides pitch signals at known steering angles, and means for receiving said pitch signals and for providing steering axis inclination angle signals for said steerable support wheels.

76. A wheel alignment system as in claim 59 wherein said angle measurement means comprises omnidirectional beam projection means mounted on each support wheel, and non-directional beam reception means mounted on each support wheel, said non-directional beam reception means on each support wheel being in optical communication with said beam projection means mounted on said other support wheels and providing received output signal indicative of beam reception.

77. A wheel alignment system as in claim 76 wherein said means for receiving and processing comprises means for detecting highest intensity beams from said receiver output signal provided by said beam reception means, means for selecting a plurality of said highest intensity beam receiver output signals corresponding to ones of said support wheels, means receiving said receiver output signals for determining angles of projection of each of said plurality of highest intensity beams, and means for combining said determined angles of projection from each of said support wheels to provide indication of projection angle of a beam extending directly from said omnidirectional beam projection means to said non-directional beam reception means.

78. A wheel alignment system as in claim 76 wherein said omnidirectional beam projection means comprises a rotation motor, an encoder coupled to said rotation motor, reflector means coupled to said rotation motor, energy emitting means for directing an energy beam toward said reflector means so that at least two rotational reflected beams are provided therefrom at known projection angles relative to the plane of the vehicle support wheel.

79. A wheel alignment system as in claim 76 wherein said omnidirectional beam projection means comprises a plurality of energy beam emitting means for producing a plurality of energy beams having known beam spread characteristics, means for mounting said plurality of energy beam emitting means so that said beams are projected at known spatial angles relative to the plane of the vehicle support wheel, and means for exciting said plurality of energy beam emitting means in predetermined sequence and for providing emission indicative signals corresponding to individual beam excitation to said angle measurement means.

80. A wheel alignment system as in claim 79 wherein said plurality of energy beam emitting means comprises ten light emitters, wherein five light emitters are mounted to project beams at substantially 27°

north spatial latitude and 5 light emitters are mounted to project beams at substantially 27°

south spatial latitude, and wherein each emitter is mounted to project beams at substantially 36°

spatial longitude separation.