Prognostic method and system for hybrid and electric vehicle components

• US 7,558,655 B2
• Filed: 09/10/2004
• Issued: 07/07/2009
• Est. Priority Date: 09/10/2004
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Shen, Zheng, Fodera, Joseph, Garg, Vijay
• Primary Examiner(s): Camby; Richard M.
• Application Number:
  US10/711,319
• Publication Number:
  US 20060058932A1
• Time in Patent Office: 1,761 Days
• Field of Search: 701 29- 36, 701/99, 701/100, 340/438, 340/439, 307 91- 108
• US Class Current: 701/29
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/32 characterised by the fuel cells
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 3/0023 Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/11 using model predictive control [MPC] strategies, i.e. control methods based on models predicting performance utilising navigation and traffic information in the control strategy B60W20/12
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 50/0205 Diagnosing or detecting failures; Failure detection models
• CPC Class Codes: B60W 50/04 Monitoring the functioning of the control system
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A prognostic method and system for testing and controlling various hybrid, fuel cell, and electric vehicle components. The tests generate test data for determining a state of the tested components. An operating strategy of the vehicle is controlled based on the state of its tested components.

Claims

1. A method for operating a vehicle, the method comprising:

applying a test signal to a vehicle electric power component;

generating a response from the component;

determining an operating state of the component based at least in part on the response to the signal;

controlling vehicle operation based at least in part on the determined operating state of the component; and

wherein determining the response includes developing a response trend based on a number of responses, comparing the response trend to a predefined trend, and determining the state of the component based in part on the comparison.

2. The method of claim 1, wherein controlling vehicle operation includes implementing a limited vehicle operating strategy based at least in part on detecting a degrading state for the component.

3. The method of claim 1, wherein controlling vehicle operation includes preventing further operation of the component.

4. The method of claim 1, wherein controlling vehicle operation includes indicating a degrading state of the component on a display.

5. The method of claim 1, wherein applying the test signal includes applying the signal to determine a forward-on voltage drop of the component.

6. The method of claim 1, wherein applying the test signal includes shutting off at least one other component and applying the signal to test for a leakage current in the component.

7. The method of claim 1, wherein applying the test signal includes applying the signal to determine a thermal impedance of the component.

8. The method of claim 1, wherein applying the test signal includes applying the signal to determine an AC impedance of the component.

9. The method of claim 1, wherein the state of the component indicates a need to limit degradation if the response trend differs from the predefined trend by a predefined margin.

10. The method of claim 1, wherein the vehicle includes an inverter for powering a motor and the component is the inverter, and wherein controlling vehicle operation includes limiting operation of the motor if the diagnosed state of the inverter indicates the inverter is degrading.

11. The method of claim 1, wherein the vehicle includes an inverter for powering a power steering unit and the component is the inverter, wherein controlling vehicle operating includes limiting operation of the power steering unit if the determined state of the inverter indicates the inverter is degrading.

12. The method of claim 1, wherein the vehicle includes an inverter for powering an air conditioning unit and the component is the inverter, and wherein controlling vehicle operation includes limiting operation of the air conditioning unit if the diagnosed state of the inverter indicates the inverter is degrading.

13. The method of claim 1, wherein the vehicle includes an auxiliary DC/DC converter and the component is the auxiliary DC/DC converter, wherein controlling vehicle operating includes limiting operation of the auxiliary DC/DC converter if the determined state of the auxiliary DC/DC converter indicates the auxiliary DC/DC converter is degrading.

14. The method of claim 1, wherein the vehicle includes an inverter for powering a fan/radiator unit and the component is the inverter, and wherein controlling vehicle operation includes limiting operation of the fan/radiator unit if the determined state of the inverter indicates the inverter is degrading.

15. A system for controlling operation of an electronic power component of a vehicle based at least in part on a determined state of the vehicle component, the system comprising:

a prognostic module to diagnose the state of the vehicle component by providing a test signal thereto and determining a degrading state of the tested component based at least in part on a response of the tested component to the test signal if the determined state is degrading faster than a predefined degradation rate; and

a vehicle system controller for controlling operation of the vehicle, the vehicle system controller being operable with the prognostic module to limit vehicle operation in response to detection of a degrading state of the tested component.

16. The system of claim 15 wherein the prognostic module test one of an inverter and a DC/DC converter.

17. A method of limiting degradation of an electrically-driven vehicle system, the method comprising:

applying a test signal to the vehicle system;

sensing a response of the vehicle system to the test signal; and

reducing operating demands on the vehicle system if the response indicates an operating capability of the vehicle system has degraded since a previous application of the test signal.

18. The method of claim 17 further comprising applying the test signal to the vehicle system when the vehicle system is inactive.

19. The method of claim 17 further comprising applying the test signal to the vehicle system when the vehicle system is active.

20. The method of claim 17 wherein the vehicle system includes a power input and a control input, wherein the method further comprises applying the test signal to the power input.