Vehicle wheel alignment apparatus and method
First Claim
1. A noncontact wheel alignment system for measuring a predetermined alignment characteristic of the wheel of a vehicle, comprising:
- light source means for projecting along an axis a structured light pattern onto the wheel of the vehicle;
optical sensor means positioned at a perspective angle relative to said axis of said projected light for receiving the reflected image of said structured light pattern off the wheel of the vehicle and converting said reflected image to corresponding electrical signals; and
processor means for processing said electrical signals and calculating therefrom said predetermined alignment characteristic of said wheel.
1 Assignment
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Accused Products
Abstract
Noncontact sensors project fanned or structured light onto the tire, while the wheel is rotated, to illuminate at least two contour lines on the surface of the tire. The contour lines are read by video cameras, positioned offset from the optical plane of the structured light, to allow triangulation in determining the spatial position of the contour lines. Radially equivalent points are selected from each contour line by an algorithm which ignores the effects of any raised lettering on the tire sidewalls. Control of the video cameras and processing of the video data is performed by parallel processor-based computer system coordinated by sequencer circuit.
92 Citations
67 Claims
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1. A noncontact wheel alignment system for measuring a predetermined alignment characteristic of the wheel of a vehicle, comprising:
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light source means for projecting along an axis a structured light pattern onto the wheel of the vehicle; optical sensor means positioned at a perspective angle relative to said axis of said projected light for receiving the reflected image of said structured light pattern off the wheel of the vehicle and converting said reflected image to corresponding electrical signals; and processor means for processing said electrical signals and calculating therefrom said predetermined alignment characteristic of said wheel. - View Dependent Claims (2, 3, 4)
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5. A laser-based noncontact wheel alignment system for measuring and adjusting a predetermined alignment characteristic of the wheel of a vehicle, comprising:
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laser source means for projecting along an axis a structured light pattern onto the wheel of the vehicle; optical sensing means positioned at a perspective angle relative to said axis of said projected light for receiving the light diffusely reflected off of the wheel of the vehicle and producing electrical signals related to the intensity of the received light; processor means for processing said electrical signals and calculating therefrom the plane of the wheel of the vehicle for determining said predetermined alignment characteristic and providing an output signal related thereto; and adjustment means for adjusting said predetermined alignment characteristic of said wheel in accordance with said output signal.
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6. A noncontact wheel alignment system for measuring a predetermined alignment characteristic of the two front steerable wheels of a vehicle, comprising:
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first light source means for projecting a structured light pattern onto one of said two front wheels; second light source means for projecting a structured light pattern onto the other of said two front wheels; first optical sensor means for receiving the reflected image of said structured light pattern off said one front wheel and converting said reflected image to corresponding electrical signals; second optical sensor means for receiving the reflected image of said structured light pattern off of said other front wheel and converting said reflected image to corresponding electrical signals; and processor means for processing said electrical signals and calculating therefrom the plane of said one front wheel and the plane of said other front wheel and determining therefrom said predetermined alignment characteristic of said two front wheels. - View Dependent Claims (7, 8, 9, 10, 11)
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12. A noncontact wheel alignment system for measuring a predetermined alignment characteristic of the wheel of a vehicle, comprising:
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light source means for projecting a structured light pattern onto the wheel of the vehicle so that at least two radially equivalent points on said wheel are illuminated thereby; optical sensing means positioned at a perspective angle relative to said light source means for receiving the light reflected off the wheel of the vehicle and producing electrical signals related to the intensity of the receiving light; and processor means for processing said electrical signals and identifying the position of said two radially equivalent points in three-dimensional space and determining therefrom said predetermined alignment characteristic of said wheel. - View Dependent Claims (13, 14, 15, 16)
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17. A noncontact laser-based wheel alignment system for measuring a predetermined alignment characteristic of the wheel of a vehicle having a tire mounted thereon, comprising:
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a first laser source for projecting a plane of light so that a first line image appears on the sidewall of said tire; a first optical sensor for receiving the reflected light from said first line image off said tire sidewall and producing electrical signals in response thereto corresponding to the intensity of the received light; a second laser source for projecting a second plane of light so that a second line image appears on the sidewall of said tire; a second optical sensor for receiving the reflected light from said second line image off said tire sidewall and producing electrical signals in response thereto corresponding to the intensity of the received light; and processor means for processing said electrical signals, identifying the location in three-dimensional space of a first point from said first line image, identifying the location in three-dimensional space of a second point from said second line image radially equivalent to said first point, calculating therefrom the plane of said tire, and determining therefrom said predetermined alignment characteristic of said wheel. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A noncontact wheel alignment system for measuring the caster of a steerable wheel of a vehicle, said steerable wheel having associated therewith a steering axis, comprising:
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light source means for projecting a structured light pattern onto said wheel so as to illuminate at least two radially equivalent points on said wheel on either side of said steering axis; optical sensor means for receiving the reflected image of said structured light pattern off of said wheel and converting said reflected light image to corresponding electrical signals; means for turning said steerable wheel about said steering axis from a first position to a second position; and processor means for processing said electrical signals, identifying the positions in three-dimensional space of said two radially equivalent points when said wheel is in both of said first and second positions, calculating therefrom the plane of said wheel in each of said first and second positions and the line of intersection between said two planes, and determining therefrom the caster of said wheel. - View Dependent Claims (30, 31, 32, 33, 34)
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35. A method of measuring a predetermined alignment characteristic of the wheel of a vehicle comprising the steps of:
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projecting a structured light pattern onto the wheel of the vehicle; sensing the reflected image of said structured light pattern from the light diffusely reflected off of said wheel and converting said sensed light image to corresponding electrical signals in accordance with the intensity of the reflected light; and determining in accordance with said electrical signals the location in three-dimensional space of selected points in said light pattern and calculating therefrom said predetermined alignment characteristic. - View Dependent Claims (36, 37, 38)
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39. A method of measuring a predetermined alignment characteristic of the two front steerable wheels of a vehicle, comprising the steps of:
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projecting a first structured light pattern onto one of said two front wheels; projecting a second structured light pattern onto the other of said two front wheels; sensing the reflected light images of said first and second structured light patterns off of said two front wheels and producing corresponding electrical signals in accordance with the intensity of said sensed light; determining in accordance with said electrical signals the location in three-dimensional space of selected points in the reflected light images of said first and second structured light patterns and calculating therefrom said predetermined alignment characteristic. - View Dependent Claims (40, 41)
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42. A method of measuring a predetermined alignment characteristic of the wheel of a vehicle having a tire mounted thereon, comprising the steps of:
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projecting a structured light pattern onto the sidewall of the tire; sensing the reflected image of said structured light pattern from the light diffusely reflected off of said tire sidewall and producing electrical signals in accordance with the inteisity of said sensed light; identifying the location in three-dimensional space of at least two points in said reflected image corresponding to radially equivalent points on said tire sidewall; calculating from said two points the plane of said tire sidewall and determining therefrom said predetermined alignment characteristic of said wheel. - View Dependent Claims (43, 44, 45, 46, 47)
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48. A method of measuring a predetermined alignment characteristic of the wheel of a vehicle having a tire mounted thereon comprising the steps of:
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rotating the tire of the vehicle at a predetermined speed; projecting a structured light pattern onto the sidewall of the rotating tire; sensing the reflected image of said structured light pattern off of said tire sidewall over a period of time corresponding substantially to the period of one revolution of said tire and producing electrical signals in accordance with the intensity of the accumulated total of light received over said period of time; and determining from said electrical signals the location in three-dimensional space of selected points in said light pattern and calculating therefrom said predetermined alignment characteristics. - View Dependent Claims (49, 50, 51)
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52. The method of measuring the caster of a steerable wheel of a vehicle, said steerable wheel having associated therewith a steering axis, comprising the steps of:
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positioning said steerable wheel in a first position; projecting a structured light pattern onto said wheel so as to illuminate at least two radially equivalent points on either side of said steering axis; sensing the reflected light image of said structured light pattern off of said wheel in said first position and producing first electrical signals corresponding the intensity of the received light; turning said steerable wheel about said steering axis from said first position to a second position; projecting said structured light pattern onto said wheel so as to illuminate at least two radially equivalent points on either side of said steering axis; sensing the reflected image of said structured light pattern off of said wheel in said second position and producing second electrical signals corresponding to the intensity of the received light; identifying in accordance with said first electrical signals the positions in three-dimensional space of said two radially equivalent points and calculating therefrom the plane of the wheel in said first position; identifying in accordance with said second electrical signals the positions in three-dimensional space of said two radially equivalent points and calculating therefrom the plane of said wheel in said second position; and determining the line of intersection between said two planes and determining therefrom the caster of said wheel.
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53. A method of aligning a vehicle wheel comprising:
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projecting structured light in at least one plane onto the surface of a member integral with said wheel to illuminate at least two contour lines on different portions of said member integral with said wheel; optically reading each of said contour lines using an optical sensor disposed at a viewing angle offset from the plane of said structured light and collecting data points indicative of the position of said contour lines; locating at least one datum point associated with each of said contour lines which corresponds to a radially equivalent portion of the surface of said wheel; using said datum points to determine the position of said wheel and providing an indication to an operator of said wheel position relative to a desired position; and adjusting the position of said wheel based on said indication in order to bring said wheel into alignment with said desired position. - View Dependent Claims (54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 65)
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64. A method of sensing the position of a wheel comprising:
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reflecting structured light from at least two points on said wheel while rotating said wheel; using at least one video camera to gather light reflected from said two points while said wheel is rotated to accumulate a signal indicative of the quantity of light gathered; from said video camera periodically reading electrical data indicative of said accumulated signal; and using said electrical data to determine the spatial position of said two points and to thereby determine the position of said wheel. - View Dependent Claims (66, 67)
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Specification