Intelligent sensor method and apparatus for an optical wheel alignment machine
First Claim
1. In a sensor for use in a wheel alignment machine to measure the orientation of a tire on a vehicle to thereby determine one or more alignment characteristics of the vehicle, said sensor being of the type having at least one light source oriented to project shaped light onto a sidewall of the tire at a plurality of spaced locations and a light responsive receiver oriented at a perspective angle with respect to said light source to receive an image that includes a portion of the shaped light that is reflected off the tire, with said light responsive receiver being operable to generate electrical signals indicative of the image, wherein the improvement comprises:
- a system of optical elements oriented relative to said light responsive receiver to provide said light responsive receiver with an optical view that includes the plurality of spaced locations of the tire, whereby portions of the shaped light that are reflected off the tire at each of the plurality of spaced locations are received by said light responsive receiver as a single image; and
an electronic circuit responsive to said electrical signals to determine the location within the image of a predetermined feature of each of the reflected portions of shaped light, said circuit further being operable to generate output data representative of the locations of said predetermined features.
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Accused Products
Abstract
A sensor method and apparatus for an optical wheel alignment machine utilizes one or more light sources, such as lasers, to project a laser line or other shaped light onto various locations about the sidewall of a tire undergoing measurement. The sensor includes a video camera or other light responsive receiver and a optical system that combines the reflected laser lines into a single image that is received by the camera. The optical system also rotates one or more of the reflected laser lines so that all of the reflected portions have the same general orientation upon entering the camera. The camera outputs a video data stream that is indicative of the image. The sensor has an electronic circuit that analyzes this video data stream in real time to determine the location in the image of a preselected feature of each of the laser lines. The circuit then outputs coordinate data indicative of the location of this feature.
The circuit is microprocessor-based and uses a comparator that compares the incoming video data stream with a threshold to determine, on a pixel-by-pixel basis, whether any particular pixel lies on or outside one of the laser lines received by the camera. For a pixel lying on a laser line, the comparator interrupts operation of the microprocessor which then determines the position within the image of that pixel. Once the pixel representing the preselected feature is found, the microprocessor uses that information to generate the coordinate output data.
104 Citations
16 Claims
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1. In a sensor for use in a wheel alignment machine to measure the orientation of a tire on a vehicle to thereby determine one or more alignment characteristics of the vehicle, said sensor being of the type having at least one light source oriented to project shaped light onto a sidewall of the tire at a plurality of spaced locations and a light responsive receiver oriented at a perspective angle with respect to said light source to receive an image that includes a portion of the shaped light that is reflected off the tire, with said light responsive receiver being operable to generate electrical signals indicative of the image, wherein the improvement comprises:
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a system of optical elements oriented relative to said light responsive receiver to provide said light responsive receiver with an optical view that includes the plurality of spaced locations of the tire, whereby portions of the shaped light that are reflected off the tire at each of the plurality of spaced locations are received by said light responsive receiver as a single image; and an electronic circuit responsive to said electrical signals to determine the location within the image of a predetermined feature of each of the reflected portions of shaped light, said circuit further being operable to generate output data representative of the locations of said predetermined features. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for generating data indicative of the orientation of a tire on a vehicle, comprising the steps of:
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(a) projecting shaped light onto a sidewall of a tire at a plurality of spaced locations, (b) receiving an image that includes portions of the shaped light reflected at an angle off said sidewall from each of said plurality of spaced locations, (c) generating a video signal that comprises a stream of pixel intensity levels arranged into successive groups of said pixel intensity levels, each of said groups representing a row of an array of pixels intensity levels that together represent said image, (d) providing a threshold intensity level that is less than those of said pixel intensity levels that represent said reflected portions of the shaped light, (e) determining a plurality of pixel counts by repeating the following steps (e1) through (e3) for each of a plurality of said groups of pixel intensity levels; (e1) comparing, in real time, said threshold intensity level with at least some of the pixel intensity levels of one of said groups, (e2) generating a logic signal when one of said pixel intensity levels exceeds said threshold intensity level, and (e3) determining, in response to an occurrence of said logic signal, one of said pixel counts in accordance with the position of said one of said pixel intensity levels within said one of said groups, and (f) using said pixel counts to generate output data representative of the spatial position of said plurality of spaced locations. - View Dependent Claims (10, 11, 12, 13)
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14. In a sensor for use in a wheel alignment machine to measure the orientation of a tire on a vehicle to thereby determine one or more alignment characteristics of the vehicle, said sensor being of the type having at least one light source oriented to project shaped light onto a sidewall of the tire at a plurality of spaced locations and a light responsive receiver oriented at a perspective angle with respect to said light source to receive an image that includes a portion of the shaped light that is reflected off the tire, with said light responsive receiver being operable to generate electrical signals indicative of the image, wherein the improvement comprises:
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an event-driven microprocessor circuit connected to receive said electrical signals from said light responsive receiver, said circuit including a microprocessor having an interrupt input; and a system of optical elements oriented relative to said light responsive receiver to provide said light responsive receiver with an optical view that includes the plurality of spaced locations of the tire, whereby portions of the shaped light that are reflected off the tire at each of the plurality of spaced locations are received by said light responsive receiver as a single image; said circuit being operable, in response to detecting in real time the presence within the image of the reflected portion of the shaped light, to generate an interrupt request on said interrupt input. - View Dependent Claims (15)
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16. In an optical sensor for generating data indicative of a spatial attribute of an object, said sensor being of the type having at least one light source oriented to project shaped light onto the object at a plurality of spaced locations and a light responsive receiver oriented at a perspective angle with respect to said light source to receive an image that includes a portion of the shaped light that is reflected off the object, with said light responsive receiver being operable to generate electrical signals indicative of the image, wherein the improvement comprises:
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an event-driven microprocessor circuit connected to receive said electrical signals from said light responsive receiver, said circuit including a microprocessor having an interrupt input; and a system of optical elements oriented relative to said light responsive receiver to provide said light responsive receiver with an optical view that includes the plurality of spaced locations of the object, whereby portions of the shaped light that are reflected off the object at each of the plurality of spaced locations are received by said light responsive receiver as a single image; said circuit being operable, in response to detecting in real time the presence within the image of the reflected portion of the shaped light, to generate an interrupt request on said interrupt input.
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Specification