Diagnostic system for a controller

• US 10,222,410 B2
• Filed: 02/12/2014
• Issued: 03/05/2019
• Est. Priority Date: 02/12/2013
• Status: Active Grant

• Current Assignee: Precision Planting LLC (AGCO Corporation)
• Original Assignee: Headsight, Inc. (AGCO Corporation)
• Inventors: Schlipf, Robert, Rassi, Johnathan, Virkler, Nathan
• Primary Examiner(s): Koval, Melissa J
• Assistant Examiner(s): Maini, Rahul
• Application Number:
  US14/767,504
• Publication Number:
  US 20150377945A1
• Time in Patent Office: 1,847 Days
• Field of Search: 324503
• CPC Class Codes: A01D 41/00 Combines, i.e. harvesters or mowers combined with threshing devices
• CPC Class Codes: A01D 41/141 Automatic header control
• CPC Class Codes: G01R 1/206 Switches for connection of measuring instruments or electric motors to measuring loads switches in general H01H
• CPC Class Codes: G01R 31/006 on road vehicles, e.g. automobiles or trucks testing of ignition installations peculiar to internal combustion engines F02P17/00
• CPC Class Codes: G01R 31/11 using pulse reflection methods
• CPC Class Codes: G01R 31/2829 Testing of circuits in sensor or actuator systems testing of apparatus for measuring electric or magnetic variables G01R35/00; testing of indicating or recording apparatus G01D; in airbag systems B60R21/0173; checking gas analysers G01N33/007; monitoring or fail-safe circuits for electromagnets H01F7/1844
• CPC Class Codes: G01R 31/58 Testing of lines, cables or conductors testing of electric windings G01R31/72

Abstract

An electrical circuit for a mobile machine, including an interface coupled between a controller and a plurality of sensors for accurately diagnosing faults in all of the sensor wires and the sensors themselves. This effective resolution reduces the downtime of the mobile machine and operator time by allowing faults to be timely isolated. The interface selectively couples a test signal to each of the sensor conductors, and also selectively couples a responsive returned characteristic signal to the controller, where the returned characteristic signal enables the controller to diagnose each of the plurality of conductors and sensors for faults. The electrical circuit may further include testing circuitry that can specifically determine a location of the determined fault in each of the plurality of conductors or each of the plurality of sensors.

Claims

1. A mobile machine having a controller and an on-board diagnostic interface, the mobile machine comprising:

first and second sensors each disposed on the mobile machine, each of the first and second sensors configured to sense a parameter as the mobile machine operates, each of the first and second sensors having a plurality of conductors coupled thereto, and wherein the first sensor is configured to generate a first sensor signal as a function of the sensed parameter and wherein the second sensor is configured to generate a second sensor signal as a function of the sensed parameter;

a controller disposed on the mobile machine and electrically coupled to each of the first and second sensors, the controller being responsive to the generated first and second sensor signal to effect a change in an operating condition of the mobile machine as the mobile machine operates; and

a diagnostic interface disposed on the mobile machine and electrically coupled between the controller and the first and second sensors, the diagnostic interface having a testing mode wherein during the testing mode the diagnostic interface is configured to;

(a) selectively communicate a first test signal to one of the plurality of conductors coupled to the first sensor to cause the first sensor to generate a first returned characteristic signal, whereupon the first returned characteristic signal is selectively routed via at least one of the other ones of the plurality of conductors coupled to the first sensor back to the controller, whereupon the controller is configured to detect existence of a fault in the plurality of conductors coupled to the first sensor as a function of the first returned characteristic signal; and

(b) selectively communicate a second test signal to one of the plurality of conductors coupled to the second sensor to cause the second sensor to generate a second returned characteristic signal, whereupon the second returned characteristic signal is selectively routed via at least one of the other ones of the plurality of conductors coupled to the second sensor back to the controller, whereupon the controller is configured to detect existence of a fault in the plurality of conductors coupled to the second sensor as a function of the second returned characteristic signal.

2. The mobile machine of claim 1, wherein the controller is further configured to detect existence of a fault in the first sensor as a function of the first returned characteristic signal and to detect existence of a fault in the second sensor as a function of the second returned characteristic signal.

3. The mobile machine of claim 2, further comprising testing circuitry configured to determine a location of the detected fault.

4. The mobile machine of claim 3, wherein the testing circuitry comprises a transmitter and receiver configured to conduct time domain reflectivity (TDR) with each of the plurality of conductors of the first sensor and each of the plurality of conductors of the second sensor.

5. The mobile machine of claim 1, wherein the diagnostic interface comprises a plurality of switches configured to selectively route the test signal to a selected one of the plurality of conductors coupled to the first sensor and to a selected on of the plurality of conductors coupled to the second sensor.

6. The mobile machine of claim 5, wherein the switches are configured to selectively route the first returned characteristic signal back to the controller and to selectively route the second returned characteristic signal back to the controller.

7. The mobile machine of claim 1, wherein the diagnostic interface comprises at least one Mux coupling the first test signal to the one of conductors coupled to the first sensor and the at least one Mux coupling the second test signal to the one of conductors coupled to the second sensor.

8. The mobile machine of claim 7, wherein the diagnostic interface comprises at least one Mux coupling the first returned characteristic signal to the controller and the at least one Mux coupling the second returned characteristic signal to the controller.

9. The mobile machine of claim 1, wherein the controller comprises a signal processor configured to compare the first and second returned characteristic signals to a table of predetermined signatures, and wherein the controller responsively determines a type of fault.

10. The mobile machine of claim 1, wherein the mobile machine is an agricultural harvester and the first and second sensors are height sensors are disposed on a header attachment coupled to the agricultural harvester, and wherein the effected change in the operating condition is a height of the header attachment above a soil surface.

11. The mobile machine of claim 9, wherein the type of fault is one of an open conductor or a shorted conductor.

12. The mobile machine of claim 9, wherein the plurality of predetermined signatures comprise a range of values, where a first range of the values is indicative of the type of fault being an open conductor, and a second range of the values is indicative of the type of fault being a shorted conductor.

13. The mobile machine of claim 12, wherein the values are correlated to a voltage measured on said plurality of conductors.

14. The mobile machine of claim 12, wherein the interface comprises at least one Mux configured to communicate the first test signal to one of the plurality of conductors coupled to the first sensor and the at least one Mux configured to communicate the second test signal to one of the plurality of conductors coupled to the second sensor.

15. The mobile machine of claim 14, wherein the interface comprises at least one Mux configured to couple the first returned characteristic signal to the controller and the at least one Mux configured to couple the second returned characteristic signal to the controller.

16. The mobile machine of claim 15 wherein the mobile machine is an agricultural harvester and the first and second sensors are height sensors are disposed on a header attachment coupled to the agricultural harvester, and wherein the effected change in the operating condition is a height of the header attachment above a soil surface.

17. The mobile machine of claim 1, whereupon the first returned characteristic signal is selectively routed via each of the other ones of the plurality of conductors coupled to the first sensor, and whereupon the second returned characteristic signal is selectively routed via each of the other ones of the plurality of conductors coupled to the second sensor.

18. A method of diagnosing multiple conductors of a sensor on a mobile machine, the method comprising:

a controller, a diagnostic interface and a sensor disposed on the mobile machine, the sensor configured to sense a parameter as the mobile machine operates, the sensor having multiple conductors coupled thereto, and wherein the sensor is configured to generate a sensor signal as a function of the sensed parameter, the controller electrically coupled to the sensor, the controller being responsive to the generated sensor signal to effect a change in an operating condition of the mobile machine as the mobile machine operates, the diagnostic interface electrically coupled between the controller and the sensor, the diagnostic interface having a testing mode, whereby during the testing mode;

the controller generating a first test signal;

the diagnostic interface routing the first test signal to a first one of the multiple conductors coupled to the sensor;

the diagnostic interface routing a first return signal from the first test signal through a second one and a third one of the multiple conductors of the sensor and back to the controller;

the controller generating a second test signal;

the diagnostic interface routing the second test signal to the second one of the multiple conductors coupled to the sensor;

the diagnostic interface routing a second return signal from the second test signal through the first one and third one of the multiple conductors of the sensor and back to the controller;

the controller diagnosing the first, second and third conductors as a function of the first and second return signals.