VIDEO OUTPUT DIAGNOSTICS FOR AUTOMOTIVE APPLICATION

• US 20130258077A1
• Filed: 03/13/2013
• Published: 10/03/2013
• Est. Priority Date: 03/16/2012
• Status: Active Grant

• Current Assignee: Magna Electronics Incorporated (Magna International Incorporated)
• Original Assignee: Magna Electronics Incorporated (Magna International Incorporated)
• Inventors: Bally, Nazar F., Miller, Patrick
• Granted Patent: US 10,182,228 B2
• Time in Patent Office: Days
• US Class Current: 348/61
• CPC Class Codes: H04N 17/00 Diagnosis, testing or measuring for television systems or their details
• CPC Class Codes: H04N 21/41422 located in transportation means, e.g. personal vehicle arrangements specially adapted for transportation systems in broadcast systems H04H20/62
• CPC Class Codes: H04N 21/44231 Monitoring of peripheral device or external card, e.g. to detect processing problems in a handheld device or the failure of an external recording device configuring of peripheral devices in general G06F9/4411; reporting information sensed by appliance or service execution status of appliance services in a home automation network H04L12/2823; monitoring the status of connected device in data switched networks H04L43/0817

Abstract

A vehicle vision system includes a diagnostic circuit for a video output cable that senses the current flowing into a video output driver. The diagnostic circuit is operable to process the current flow to determine an open-circuit condition of the video cable, a short to ground condition of the video cable and/or a short to battery condition of the video cable. The circuit may process the current flow passing through an electrical resistor connected in series between the video output driver and the video driver power supply.

Claims

1. A system for determining a diagnostic condition of a video connection with a display module in a vehicle, the system comprising:

video processing circuitry providing a video signal;

a video driver receiving the video signal and amplifying it for transmission over a video cable, wherein the video driver is powered by a video driver power supply;

a current sensor in connection with the video driver power supply;

a microcontroller operatively connected to the current sensor to determine the current sensed by the current sensor;

wherein the microcontroller receives a short to battery input; and

wherein the microcontroller is operable to determine a diagnostic condition of the video cable based at least in part on (a) the determination of current sensed by the current sensor and (b) the short to battery input.

2. The system of claim 1, wherein the current sensor comprises a current sense resistor disposed in electrical series connection between the video driver and the video driver power supply, and wherein the microcontroller is operable to determine the current flow through the current sense resistor.

3. The system of claim 1, wherein the microcontroller determines (i) an open circuit condition when the current sensed by the current sensor falls below a predetermined quantity, (ii) a short to battery condition when the current sensed by the current sensor exceeds a predetermined quantity and the short to battery input is triggered, and (iii) a short to ground condition when the current sensed by the current sensor exceeds a predetermined quantity and the short to battery input is not triggered.

4. The system of claim 3, including a current sense amplifier connected across the terminals of the current sensor, the current sense amplifier having an output connected to the microcontroller, and the microcontroller having analog to digital circuitry for converting the output of the current sense amplifier to the current sensed by the current sensor.

5. The system of claim 1, wherein the microcontroller determines at least one of (i) an open circuit condition when the current sensed by the current sensor falls below a predetermined quantity, (ii) a short to battery condition when the current sensed by the current sensor exceeds a predetermined quantity and the short to battery input is triggered, and (iii) a short to ground condition when the current sensed by the current sensor exceeds a predetermined quantity and the short to battery input is not triggered.

6. The system of claim 5, including a current sense amplifier connected across the terminals of the current sensor, the current sense amplifier having an output connected to the microcontroller, and the microcontroller having analog to digital circuitry for converting the output of the current sense amplifier to the current sensed by the current sensor.

7. The system of claim 1, wherein the microcontroller determines an open circuit condition when the current sensed by the current sensor falls below a predetermined quantity.

8. The system of claim 1, wherein the microcontroller determines a short to battery condition when the current sensed by the current sensor exceeds a predetermined quantity and the short to battery input is triggered.

9. The system of claim 1, wherein the microcontroller determines a short to ground condition when the current sensed by the current sensor exceeds a predetermined quantity and the short to battery input is not triggered.

10. The system of claim 1, comprising a video display operable to display video images responsive to the video signal, wherein the video display is disposed in a cabin of a vehicle equipped with the system and is viewable by a driver of the equipped vehicle when the driver is normally operating the equipped vehicle.

11. The system of claim 1, wherein the short to battery input is output by the video driver to the microcontroller.

12. A method for determining a diagnostic condition of a video connection with a display module in a vehicle, the method comprising:

providing a video signal;

amplifying the video signal via a video driver for transmission over a video cable, the video driver being powered by a video driver power supply;

sensing the current flowing into the video driver through the video driver power supply;

determining the output voltage of the video driver; and

determining a diagnostic condition of the video cable based at least in part on at least two of (a) the sensed current flowing into the video driver, (b) the output voltage of the video driver and (c) a short to battery condition.

13. The method of claim 12, comprising:

determining an open circuit condition when the current flowing into the video driver falls below a predetermined quantity;

determining a short to battery condition when the current flowing into the video driver exceeds a predetermined quantity and the output voltage of the video driver is higher than a voltage of the video driver power supply; and

determining a short to ground condition when the current flowing into the video driver exceeds a predetermined quantity and the output voltage of the video driver is not higher than a voltage of the video driver power supply.

14. The method of claim 12, comprising at least one of:

determining an open circuit condition when the current flowing into the video driver falls below a predetermined quantity;

determining a short to battery condition when the current flowing into the video driver exceeds a predetermined quantity and the output voltage of the video driver is higher than a voltage of the video driver power supply; and

determining a short to ground condition when the current flowing into the video driver exceeds a predetermined quantity and the output voltage of the video driver is not higher than a voltage of the video driver power supply.

15. The method of claim 12, comprising determining an open circuit condition when the current flowing into the video driver falls below a predetermined quantity.

16. The method of claim 12, comprising (a) determining a short to battery condition when the current flowing into the video driver exceeds a predetermined quantity and the output voltage of the video driver is higher than a voltage of the video driver power supply, and (b) determining a short to ground condition when the current flowing into the video driver exceeds a predetermined quantity and the output voltage of the video driver is not higher than a voltage of the video driver power supply.

17. A system for determining a diagnostic condition of a video connection with a display module in a vehicle, the system comprising:

video processing circuitry providing a video signal;

a video driver receiving the video signal and amplifying it for transmission over a video cable, wherein the video driver is powered by a video driver power supply;

a video display operable to display video images responsive to the video signal, wherein the video display is disposed in a cabin of a vehicle equipped with the system and is viewable by a driver of the equipped vehicle when the driver is normally operating the equipped vehicle;

a current sensor in connection with the video driver power supply;

a microcontroller operatively connected to the current sensor to determine the current sensed by the current sensor;

wherein the microcontroller receives a short to battery input;

wherein the microcontroller is operable to determine a diagnostic condition of the video cable based at least in part on (a) the determination of current sensed by the current sensor and (b) the short to battery input; and

wherein the microcontroller determines at least one of (i) an open circuit condition when the current sensed by the current sensor falls below a predetermined quantity, (ii) a short to battery condition when the current sensed by the current sensor exceeds a predetermined quantity and the short to battery input is triggered, and (iii) a short to ground condition when the current sensed by the current sensor exceeds a predetermined quantity and the short to battery input is not triggered.

18. The system of claim 17, wherein the current sensor comprises a current sense resistor disposed in electrical series connection between the video driver and the video driver power supply, and wherein the microcontroller is operable to determine the current flow through the current sense resistor.

19. The system of claim 18, including a current sense amplifier connected across the terminals of the current sense resistor, the current sense amplifier having an output connected to the microcontroller, and the microcontroller having analog to digital circuitry for converting the output of the current sense amplifier to the current sensed by the current sense resistor.

20. The system of claim 17, wherein the short to battery input is output by the video driver to the microcontroller.