Fault detection and mitigation in hybrid drive system

• US 8,950,249 B2
• Filed: 08/05/2013
• Issued: 02/10/2015
• Est. Priority Date: 06/11/2009
• Status: Active Grant

• Current Assignee: Danfoss Power Solutions II Technology A/S
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Stoner, Michael Anthony, Hawkins, Thomas D., Simpson, Douglas D.
• Primary Examiner(s): Kirkland, III, Freddie
• Application Number:
  US13/959,350
• Publication Number:
  US 20130317716A1
• Time in Patent Office: 554 Days
• Field of Search: 73/37, 731/142.5, 731/150.1
• US Class Current: 73/115.01
• CPC Class Codes: B60K 6/12 by means of a chargeable fluidic accumulator
• CPC Class Codes: B60K 6/26 characterised by the motors or the generators
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 20/50 Control strategies for responding to system failures, e.g. for fault diagnosis, failsafe operation or limp mode
• CPC Class Codes: F02D 2041/1432 the system including a filter, e.g. a low pass or high pass filter
• CPC Class Codes: F02D 2041/224 Diagnosis of the fuel system
• CPC Class Codes: F02D 2041/225 Leakage detection
• CPC Class Codes: F02D 2041/227 Limping Home, i.e. taking specific engine control measures at abnormal conditions
• CPC Class Codes: F02D 29/02 peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F04B 49/103 Responsive to speed
• CPC Class Codes: F04B 51/00 Testing machines, pumps, or pumping installations
• CPC Class Codes: G01M 17/00 Testing of vehicles testing fluid tightness G01M3/00; testing elastic properties of bodies or chassis, e.g. torsion-testing, G01M5/00; testing alignment of vehicle headlight devices G01M11/06; testing of engines G01M15/00
• CPC Class Codes: G01M 3/00 Investigating fluid-tightness of structures
• CPC Class Codes: G01M 3/002 by using thermal means
• CPC Class Codes: G01M 3/26 by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

Fault detection and response systems and processes can be used for pumps, e.g., pump/motors used in hybrid vehicles. The fault detection systems determine when certain operating conditions, which may affect the proper operation of the system, occur. The response systems take appropriate action based on which fault conditions are triggered. Example fault detection systems and processes include detection systems for different types of leaks, sensor malfunctions, or operation errors.

Claims

1. A limit method for limiting a speed of an engine of a vehicle having a first power source and a second power source, the method comprising:

determining that the vehicle has failed to disengage the second power source from the engine;

obtaining a pump speed of a pump of the second power source;

obtaining a gear ratio of the pump of the second power source;

determining a maximum allowable pump speed based at least partially on the gear ratio; and

sending a limit command to the engine of the vehicle if the obtained pump speed is greater than the maximum allowable pump speed.

2. The limit method of claim 1, wherein determining that the vehicle has failed to disengage the second power source from the engine comprises:

obtaining a first data signal representing a command sent to a clutch of the engine;

obtaining a second data signal representing a current status of the clutch;

determining that the current status of the clutch does not sufficiently match the command sent to the clutch for at least a set period of time; and

triggering a failure to disengage fault.

3. The limit method of claim 2, wherein the failure to disengage fault is a disabling fault.

4. The limit method of claim 2, further comprising storing the failure to disengage fault in non-volatile memory.

5. The limit method of claim 1, wherein the second power source includes a pump-motor assembly, a fluid reservoir, and an energy storage unit.

6. The limit method of claim 5, wherein the second power source includes an engagement assembly that is configured to selectively engage the pump-motor assembly to a drive line of the vehicle.

7. The limit method of claim 6, wherein the engagement assembly is configured to selectively engage the pump-motor assembly to the drive line during acceleration of the vehicle.

8. The limit method of claim 6, wherein the engagement assembly is configured to selectively engage the pump-motor assembly to the drive line during deceleration of the vehicle.

9. The limit method of claim 1, wherein the first power source includes an internal combustion engine.

10. The limit method of claim 1, wherein the pump speed is obtained using a pump speed sensor.

11. The limit method of claim 1, wherein each power source is operated by a respective control unit, each control unit including a processor and a memory for data storage.

12. The limit method of claim 11, wherein determining that the vehicle has failed to disengage the second power source from the engine comprises checking whether a failure to disengage fault is stored in the memory of the second power source.

13. The limit method of claim 11, wherein the control unit of the second power source is configured to limit a torque output of the first power source when the second power source is actively engaged to a drive line by which the second power source couples to a drive line.

14. The limit method of claim 11, wherein the gear ratio is obtained from the memory of the second power source.

15. The limit method of claim 11, wherein the gear ratio is obtained from the memory of the first power source.

16. The limit method of claim 1, wherein the gear ratio is obtained from user input.

17. The limit method of claim 1, wherein the gear ratio is obtained from an upload signal from a remote computer.

18. The limit method of claim 1, wherein the second power source is configured to act as a motor during acceleration of the vehicle, and wherein the second power source is configured to act as a pump during deceleration of the vehicle.

19. The limit method of claim 1, further comprising warning the user of the failure to disengage fault.

20. The limit method of claim 1, wherein the engine remains limited even after the vehicle is keyed off and keyed on again.