System and method for detecting alternator condition

• US 20040049361A1
• Filed: 09/10/2002
• Published: 03/11/2004
• Est. Priority Date: 09/10/2002
• Status: Active Grant

• Current Assignee: Bendix Commercial Vehicle Systems LLC (Estate of Heinz Hermann Thiele)
• Original Assignee: Bendix Commercial Vehicle Systems LLC (Estate of Heinz Hermann Thiele)
• Inventors: Grolle, Kenneth A., Holler, Gusztav, Macnamara, Joseph M., Thakkar, Kirit A., Hamdan, Marv M.
• Granted Patent: US 6,862,504 B2
• Time in Patent Office: Days
• US Class Current: 702/115
• CPC Class Codes: G01R 31/007 using microprocessors or computers

Abstract

A system and method for detecting alternator condition is provided. Information is taken from the vehicle powerline and the communication links, and processed by the vehicle ECU, such as the vehicle antilocking brake system ECU, to obtain data. The battery voltage ripple amplitude is then calculated and compared at different engine speeds. If the difference in the ripple amplitude at the different engine speeds is greater than a predetermined threshold value, a signal is sent indicating that the alternator has failed.

Claims

1. A method for detecting alternator condition, comprising the steps of:

sampling battery voltage;

calculating an average battery voltage, a maximum battery voltage and a minimum battery voltage;

calculating a differential battery voltage from the maximum battery voltage minus the minimum battery voltage;

detecting the engine speed; and

comparing the differential battery voltage at different engine speeds.

2. The method of claim 1, further comprising the step of sending a signal indicating alternator condition.

3. The method of claim 1, wherein the battery voltage is sampled in predetermined intervals.

4. The method of claim 1, further comprising the step of filtering the battery voltage data.

5. The method of claim 1, further comprising the steps of comparing the average battery voltage to a predetermined threshold value and sending a signal indicating alternator failure if the average voltage is less than the predetermined threshold value.

7. The method of claim 1, wherein data is calculated and stored within a vehicle antilocking braking system ECU.

8. The method of claim 7, wherein data is delivered to the antilocking braking system ECU using one or more pre-existing vehicle communication buses.

9. The method of claim 1, wherein the step of sending a signal indicating alternator condition further comprises the step of indicating a partially failed alternator when the differential battery voltage at a first engine speed is more than approximately 2 times the differential battery voltage at a second engine speed.

10. The method of claim 9, wherein the first engine speed is in the range of approximately 1,000 to 1, 500 RPM.

11. The method of claim 9, wherein the second engine speed is in the range of approximately 500 to 900 RPM.

12. The method of claim 1, wherein the alternator is a commercial vehicle alternator.

6. The method of claim 6, wherein the predetermined threshold value is approximately 12 volts.

13. A system for detecting alternator condition comprising:

an alternator;

a battery;

an ECU incorporating a software plug-in for determining alternator condition; and

one or more communication buses for obtaining parameters or reporting alternator status.

14. The system of claim 13, further comprising one or more alternator condition signals.

15. The system of claim 13, wherein the ECU is a vehicle antilocking brake system ECU.

16. The system of claim 13, wherein the ECU further comprises an A/D converter.

17. The system of claim 13, wherein the communication bus is the J1587, J2497 or J1939 bus.

18. A method of detecting alternator condition on a commercial vehicle comprising the steps of:

sampling powerline voltage from the commercial vehicle battery in predetermined intervals;

calculating an average voltage, a maximum voltage, a minimum voltage, and a differential voltage using the antilocking braking system ECU;

detecting the engine speed; and

comparing the differential voltage at different engine speeds.

19. The method of claim 18, further comprising the step of sending a signal indicating alternator condition.

20. The method of claim 19, wherein the signal is sent to one or more alternator condition indicators within the cab of the commercial vehicle.

21. The method of claim 18, further comprising the step of filtering the battery voltage data.

22. The method of claim 18, further comprising the steps of comparing the average battery voltage to a predetermined threshold value and sending a signal indicating alternator failure if the average voltage is less than the predetermined threshold value.

23. The method of claim 18, wherein the step of sending a signal indicating alternator condition further comprises the step of indicating a partially failed alternator when the differential battery voltage at a first engine speed is more than approximately 2 times the differential battery voltage at a second engine speed.

24. A software plug-in that determines the condition of an alternator by measuring the voltage of a battery at different engine speeds and comparing the ripple amplitude of said voltage measurement at the different engine speeds.

25. The software plug-in of claim 24, wherein the software plug-in is in a vehicle'"'"'s anti-locking brake system ECU.

26. The software plug-in of claim 25, wherein the vehicle anti-locking brake system is that of a commercial vehicle.

27. The software plug-in of claim 24, wherein in the software plug-in generates a signal that indicates the alternator condition.

28. The software plug-in of claim 27, wherein the signal is sent to one or more alternator condition indicators within the cab of a commercial vehicle.