Integrated circuit image sensor for wheel alignment systems

• US 20090073425A1
• Filed: 09/18/2007
• Published: 03/19/2009
• Est. Priority Date: 09/18/2007
• Status: Active Grant

• Current Assignee: Snap-On Incorporated
• Original Assignee: Snap-On Incorporated
• Inventors: Rogers, Steven W., Bryan, Eric F., Kling, Michael J. III
• Granted Patent: US 7,855,783 B2
• Time in Patent Office: Days
• US Class Current: 356/139.90
• 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

Abstract

An integrated circuit (IC), for use in an imaging module of a wheel alignment system, incorporates an image sensor as well as a number of other features. Some of the added features are implemented within the integrated circuit. The IC also incorporates interfacing for signaling or communication with other devices in the imaging module or elsewhere in the wheel alignment system. Some examples of added internal features include a temperature sensor, unique chip ID, and chip power control. The addition of analog and/or digital I/O to the integrated circuit enables control of an image module illumination function, control of an imaging module positioning function, various cooling functions, and operator interface control. A communications hub may be added to the IC, to enable operation in a networked system environment.

Claims

1. An integrated circuit for use in a wheel alignment system, the integrated circuit comprising:

a programmable controller;

an image sensor controlled by the programmable controller, for imaging a field of view encompassing a target subject of a wheel alignment measurement by the system and generating representative image data;

a data communication interface configured for transmitting information based on the representative image data to a host computer of the wheel alignment system; and

an input/output interface, for control signaling with at least one other element of the system, to enable the controller to control an operation of the at least one other element.

2. The integrated circuit of claim 1, wherein the input/output interface comprises a digital input/output interface, configured for signal communication between the controller and the at least one other element of the system, to enable control of at least one system operation selected from the group consisting of:

brightness control of a strobe for illumination of a target of the system;

movement of at least one system element effecting optical input to the image sensor;

cooling of the integrated circuit; and

activation of one or more user perceptible indicators, for indicating one or more conditions regarding operations of the wheel alignment system.

3. The integrated circuit of claim 2, wherein the digital input/output interface also is configured for enabling the controller to receive a condition signal relating to a condition sensed by the wheel alignment system.

4. The integrated circuit of claim 1, wherein the input/output interface comprises an analog input/output interface, configured for signal communication between the controller and the at least one other element of the system, to enable control of at least one system operation selected from the group consisting of:

brightness control of a strobe for illumination of a target of the system;

movement of at least one system element effecting optical input to the image sensor;

cooling of the integrated circuit; and

activation of one or more user perceptible indicators, for indicating one or more conditions regarding operations of the wheel alignment system.

5. The integrated circuit of claim 4, wherein the analog input/output interface also is configured for enabling the controller to receive a signal representing a system condition, including at least one of sensed motor current, sensed motor speed and sensed position of an imaging module containing the integrated circuit.

6. The integrated circuit of claim 1, further comprising an analog to digital converter coupled to the image sensor for converting analog image signals from the image sensor into digital image data.

7. The integrated circuit of claim 6, wherein the controller comprises a processor programmed for pre-processing the representative digital image data, to produce the information for communication to the host.

8. The integrated circuit of claim 7, wherein the pre-processing of the digital image data performed by the processor comprises at least one data processing operation selected from the group consisting of:

calculating gradient information from the digital image data;

extracting data for a region of interest from the digital image data;

performing a background subtraction on the digital image data;

compressing the digital image data;

recognizing an image feature from the digital image data;

analyzing an image feature from the digital image data;

calculating a target plane from the digital image data;

calculating vehicle wheel orientation from the digital image data;

calculating wheel alignment angle from the digital image data; and

comparing a wheel alignment angle calculated from the digital image data to a vehicle wheel alignment specification.

9. The integrated circuit of claim 1, further comprising a sensor for sensing a temperature in the vicinity of the integrated circuit, wherein the input/output interface provides signaling from the controller to a cooling device of the system, to enable the controller to control the cooling device based on the sensed temperature.

10. The integrated circuit of claim 1, further comprising a non-volatile memory for storing at least one of calibration data for correcting non-linearity in the imaging sensor and individual pixel gain correction factors for correcting measurement accuracy.

11. The integrated circuit of claim 1, further comprising a unique chip identification that provides identification for a specific imaging module containing the integrated circuit.

12. The integrated circuit of claim 1, further comprising a communication hub.

13. In a wheel alignment system, the wheel alignment system having an imaging module, a host computer responsive to the imaging module for outputting a vehicle wheel alignment parameter to a user, the improvement comprising:

an integrated circuit in the imaging module, the integrated circuit comprising;

an image sensor, for imaging a field of view encompassing an optical target related to a wheel of a subject vehicle and generating representative image data;

a programmable controller coupled to the image sensor and programmed to pre-process the representative image data and to control at least one other operation of the wheel alignment system;

a data communication interface configured for transmitting the pre-processed data from the controller to the host computer; and

an input/output interface, for signaling with at least one other element of the system, to enable the controller to receive external sensor data from or to send a control signal to the at least one other element of the wheel alignment system.

14. The improvement of claim 13, wherein the integrated circuit further comprises an analog to digital converter coupled to the image sensor, for converting analog image signals from the image sensor into digital image data.

15. The improvement of claim 13, wherein the pre-processing of the digital image data performed by the processor comprises at least one data processing operation selected from the group consisting of:

calculating gradient information from the digital image data;

extracting data for a region of interest from the digital image data;

performing a background subtraction on the digital image data;

compressing the digital image data;

recognizing an image feature from the digital image data;

analyzing an image feature from the digital image data;

calculating a target plane from the digital image data;

calculating vehicle wheel orientation from the digital image data;

calculating wheel alignment angle from the digital image data; and

comparing a wheel alignment angle calculated from the digital image data to a vehicle wheel alignment specification.

16. The improvement of claim 13, wherein the input/output interface comprises an analog input/output interface and a digital input/output interface.

17. The improvement of claim 13, wherein the integrated circuit further comprises a temperature sensor on the chip for sensing a temperature within the imaging module, and the at least one other operation of the wheel alignment system comprises cooling of the imaging module responsive to the sensed temperature.

18. The improvement of claim 13, wherein the integrated circuit further comprises a non-volatile memory for storing at least one of calibration data for correcting non-linearity in the imaging sensor and individual pixel gain correction factors for correcting measurement accuracy

19. The improvement of claim 13, wherein the integrated circuit further comprises a unique chip identification that provides identification for a specific imaging module of the system containing the integrated circuit.

20. The improvement of claim 13, wherein the integrated circuit further comprises a communication hub.