Fault detection and mitigation in hybrid drive system

• US 8,499,616 B2
• Filed: 06/11/2010
• Issued: 08/06/2013
• Est. Priority Date: 06/11/2009
• Status: Active Grant

• Current Assignee: Danfoss Power Solutions II Technology A/S
• Original Assignee: ADC Telecommunications Incorporated (TE Connectivity Limited)
• Inventors: Stoner, Michael Anthony, Hawkins, Thomas D., Simpson, Douglas D.
• Primary Examiner(s): Williams, Hezron E
• Assistant Examiner(s): Frank, Rodney T
• Application Number:
  US12/814,303
• Publication Number:
  US 20100313849A1
• Time in Patent Office: 1,152 Days
• Field of Search: 73/40
• US Class Current: 73/40
• 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 detection method for detecting a gas leak in a pump system having an accumulator spaced from a reservoir, the accumulator including a gas chamber separated from a liquid chamber, the method comprising:

obtaining a fluid temperature of a fluid to be transferred between the reservoir and the liquid chamber of the accumulator;

obtaining a fluid pressure of the fluid;

estimating a gas pressure based on the obtained fluid temperature and the obtained fluid pressure;

comparing the estimated gas pressure to a first threshold;

triggering a first fault if the estimated gas pressure is below the first threshold

calculating a running average of the estimated gas pressure;

comparing the running average to a second threshold; and

triggering a second fault if the running average is less than the second threshold.

2. The detection method of claim 1, wherein the second threshold is higher than the first threshold.

3. The detection method of claim 1, further comprising calculating what the estimated gas pressure would be at a predetermined temperature based on the obtained fluid pressure and the obtained fluid temperature.

4. The detection method of claim 1, wherein obtaining the fluid temperature comprises obtaining the fluid temperature from a temperature sensor at the reservoir.

5. The detection method of claim 1, wherein obtaining the fluid pressure comprises obtaining the fluid pressure from a pressure sensor at the accumulator.

6. The detection method of claim 1, further comprising:

obtaining a pump case temperature;

obtaining a fluid reservoir temperature;

comparing the pump case temperature with the fluid reservoir temperature; and

determining a temperature difference between the pump case temperature and the fluid reservoir temperature.

7. A detection method for detecting an oil leak in a pump system having an accumulator spaced from a reservoir, the accumulator including a gas chamber separated from a liquid chamber, the method comprising:

obtaining a data signal representing a fluid temperature of a fluid at the reservoir;

obtaining a data signal representing a fluid pressure of the fluid at the accumulator;

estimating a level of the fluid in the reservoir based on the obtained fluid temperature and the obtained fluid pressure;

obtaining a data signal representing an actual level of the fluid at the reservoir;

comparing the estimated level of the fluid to the actual level of the fluid;

triggering a fault when the actual level is different than the estimated level more than a threshold amount.

8. The detection method of claim 7, wherein the pump system is operably connected to a vehicle, and wherein the detection method further comprises:

determining whether vehicle is moving; and

adjusting the threshold amount based on whether or not the vehicle is determined to be moving.

9. The detection method of claim 8, wherein adjusting the threshold amount comprises lowering the threshold amount when the vehicle is stationary.

10. The detection method of claim 8, wherein the threshold amount is calculated based at least partially on tolerance of sensors providing the data signals.

11. A detection method for detecting a gas leak in a pump system having an accumulator spaced from a reservoir, the accumulator including a gas chamber separated from a liquid chamber, the method comprising:

obtaining a fluid temperature of a fluid to be transferred between the reservoir and the liquid chamber of the accumulator;

obtaining a fluid pressure of the fluid;

estimating a gas pressure based on the obtained fluid temperature and the obtained fluid pressure;

calculating a value of what the estimated gas pressure would be at a predetermined temperature based on the obtained fluid pressure and the obtained fluid temperature;

comparing the value of what the estimated gas pressure would be at the predetermined temperature to a first threshold;

triggering a first fault if the value of what the estimated gas pressure would be at the predetermined temperature is below the first threshold.

12. The detection method of claim 11, wherein obtaining the fluid temperature comprises obtaining the fluid temperature from a temperature sensor at the reservoir.

13. The detection method of claim 11, wherein obtaining the fluid pressure comprises obtaining the fluid pressure from a pressure sensor at the accumulator.

14. The detection method of claim 11, further comprising:

obtaining a pump case temperature;

obtaining a fluid reservoir temperature;

comparing the pump case temperature with the fluid reservoir temperature; and

determining a temperature difference between the pump case temperature and the fluid reservoir temperature.

15. A detection method for detecting a gas leak in a pump system having an accumulator spaced from a reservoir, the accumulator including a gas chamber separated from a liquid chamber, the method comprising:

obtaining a fluid temperature of a fluid to be transferred between the reservoir and the liquid chamber of the accumulator;

obtaining a fluid pressure of the fluid from a pressure sensor at the accumulator;

estimating a gas pressure based on the obtained fluid temperature and the obtained fluid pressure;

comparing the estimated gas pressure to a first threshold;

triggering a first fault if the estimated gas pressure is below the first threshold.

16. The detection method of claim 15, wherein obtaining the fluid temperature comprises obtaining the fluid temperature from a temperature sensor at the reservoir.

17. A detection method for detecting a gas leak in a pump system having an accumulator spaced from a reservoir, the accumulator including a gas chamber separated from a liquid chamber, the method comprising:

obtaining a pump case temperature;

obtaining a fluid reservoir temperature;

comparing the pump case temperature with the fluid reservoir temperature;

determining a temperature difference between the pump case temperature and the fluid reservoir temperature; and

performing the following operations when the temperature difference is below a certain threshold;

obtaining a fluid temperature of a fluid to be transferred between the reservoir and the liquid chamber of the accumulator;

obtaining a fluid pressure of the fluid;

estimating a gas pressure based on the obtained fluid temperature and the obtained fluid pressure;

comparing the estimated gas pressure to a first threshold; and

triggering a first fault if the estimated gas pressure is below the first threshold.

18. The detection method of claim 17, wherein obtaining the fluid temperature comprises obtaining the fluid temperature from a temperature sensor at the reservoir.