METHOD AND APPARATUS FOR ON-BOARD/OFF-BOARD FAULT DETECTION

• US 20160217628A1
• Filed: 08/29/2012
• Published: 07/28/2016
• Est. Priority Date: 08/29/2012
• Status: Abandoned Application

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: GHONEIM, YOUSSEF A., HOWELL, MARK N.
• Application Number:
  US14/423,816
• Publication Number:
  US 20160217628A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60K 2015/03243 characterised by special pumps, the mounting thereof
• CPC Class Codes: B60W 2050/022 Actuator failures
• CPC Class Codes: B60W 2050/046 involving external transmission of data to or from the vehicle, e.g. via telemetry, satellite, Global Positioning System [GPS]
• CPC Class Codes: B60W 2756/10 Involving external transmission of data to or from the vehicle
• CPC Class Codes: G05B 2223/06 Remote monitoring
• CPC Class Codes: G05B 23/0245 based on a qualitative model, e.g. rule based; if-then decisions
• CPC Class Codes: G07C 5/008 communicating information to a remotely located station transmission systems for measured values G08C
• CPC Class Codes: G07C 5/02 Registering or indicating driving, working, idle, or waiting time only apparatus forming part of taximeters G07B13/00
• CPC Class Codes: G07C 5/0808 Diagnosing performance data testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005
• CPC Class Codes: G07C 5/0816 Indicating performance data, e.g. occurrence of a malfunction

Abstract

A vehicle includes a plurality of subsystems that are monitored during on-going operation. A method for monitoring a subsystem includes monitoring states of commanded and observed parameters for the subsystem. Deviations in the observed parameters are determined off-board the vehicle. The deviations are employed to determine magnitudes of subsystem operating signatures off-board the vehicle. The subsystem operating signatures are employed to identify presence of a subsystem fault and isolate the subsystem fault off-board the vehicle. The presence of the isolated fault is communicated to the vehicle.

Claims

1. A method for monitoring a subsystem for a vehicle during ongoing operation, comprising:

monitoring states of commanded and observed parameters for the subsystem;

determining deviations in the observed parameters off-board the vehicle;

employing the deviations to determine magnitudes of subsystem operating signatures off-board the vehicle;

employing the subsystem operating signatures to identify presence of a subsystem fault and isolate the subsystem fault off-board the vehicle; and

communicating the presence of the isolated fault to the vehicle.

2. The method of claim 1, wherein determining deviations in the observed parameters off-board the vehicle comprises:

executing an off-line analysis employing parametric data representing operation of the subsystem to develop a system model for the subsystem;

employing the system model to determine expected states for the observed parameters based upon the commanded parameters off-board the vehicle; and

determining deviations in the observed parameters off-board the vehicle based upon comparisons of the expected states and the monitored states for the observed parameters.

3. The method of claim 1, wherein employing the deviations to determine magnitudes of subsystem operating signatures off-board the vehicle comprises:

developing a plurality of subsystem operating signatures {circumflex over (T)}₁, {circumflex over (T)}₂, . . . {circumflex over (T)}_N associated with the observed parameters off-line;

executing a training algorithm that determines a weighting vector for the subsystem operating signatures {circumflex over (T)}₁, {circumflex over (T)}₂, . . . {circumflex over (T)}_N associated with specific faults for the selected subsystem; and

employing the weighting vector for the subsystem operating signatures {circumflex over (T)}₁, {circumflex over (T)}₂, . . . {circumflex over (T)}_N and the deviations in the observed parameters to determine said magnitudes of the subsystem operating signatures.

4. The method of claim 1, wherein employing the subsystem operating signatures to identify presence of a subsystem fault and isolate the subsystem fault off-board the vehicle comprises:

for each of the subsystem operating signatures, identifying a signature attribute based upon a magnitude of the respective subsystem operating signature in relation to a plurality of error thresholds; and

employing a fault threshold set to identify presence of the subsystem fault and isolate the subsystem fault based upon the signature attributes for all of the subsystem operating signatures.

5. A method for monitoring a subsystem for a vehicle, comprising:

monitoring states of commanded parameters and observed parameters for the subsystem on board the vehicle during ongoing operation;

transmitting the commanded parameters and the observed parameters for the subsystem to a subsystem monitoring system remote from the vehicle;

employing the subsystem monitoring system to;

execute a system model to determine expected states for the observed parameters based upon the commanded parameters,

determine deviations in the observed parameters based upon comparisons of the expected states and the monitored states for the observed parameters,

determine magnitudes of subsystem operating signatures based upon the deviations in the observed parameters,

identify presence of a subsystem fault and isolate the subsystem fault based upon the subsystem operating signatures, and

communicate the presence of the isolated fault to the vehicle.

6. The method of claim 5, wherein employing the remote subsystem monitoring system to determine deviations in the observed parameters based upon comparisons of the expected states and the monitored states for the observed parameters comprises:

executing an off-line analysis employing parametric data representing operation of the subsystem to develop a system model associated with the subsystem;

employing the system model to determine expected states for the observed parameters based upon the commanded parameters; and

determining deviations in the observed parameters based upon comparisons of the expected states and the monitored states for the observed parameters.

7. The method of claim 5, wherein employing the remote subsystem monitoring system to determine magnitudes of subsystem operating signatures based upon the deviations in the observed parameters comprises:

developing a plurality of subsystem operating signatures {circumflex over (T)}₁, {circumflex over (T)}₂, . . . {circumflex over (T)}_N associated with the observed parameters;

executing a training algorithm that determines a weighting vector for the subsystem operating signatures {circumflex over (T)}₁, {circumflex over (T)}₂, . . . {circumflex over (T)}_N associated with specific faults for the selected subsystem; and

employing the weighting vector for the subsystem operating signatures {circumflex over (T)}₁, {circumflex over (T)}₂, . . . {circumflex over (T)}_N and the deviations in the observed parameters to determine said magnitudes of the subsystem operating signatures.

8. The method of claim 5, wherein employing the remote subsystem monitoring system to identify presence of a subsystem fault and isolate the subsystem fault based upon the subsystem operating signatures comprises:

for each of the subsystem operating signatures, identifying a signature attribute based upon a magnitude of the respective subsystem operating signature in relation to a plurality of error thresholds; and

employing a fault threshold set to identify presence of a subsystem fault and isolate the subsystem fault based upon the signature attributes for the subsystem operating signatures.

9. A method for monitoring a returnless fuel subsystem for a vehicle, comprising:

monitoring commanded and observed parameters of the returnless fuel subsystem on-board the vehicle during vehicle operation;

determining deviations in the observed parameters off-board the vehicle;

employing the deviations to determine magnitudes of the returnless fuel subsystem operating signatures off-board the vehicle;

employing the operating signatures to identify and isolate a fault in the returnless fuel subsystem the subsystem fault off-board the vehicle; and

communicating the fault in the returnless fuel subsystem to the vehicle.

10. The method of claim 9, wherein monitoring commanded parameters of the returnless fuel subsystem on-board the vehicle during vehicle operation comprises monitoring a pump voltage command.

11. The method of claim 9, wherein monitoring observed parameters of the returnless fuel subsystem on-board the vehicle during vehicle operation comprises monitoring an electrical current, system pressure, and rotational speed associated with an electrically-powered pump motor of a fuel pump of the returnless fuel subsystem.

12. The method of claim 9, wherein determining deviations in the observed parameters off-board the vehicle comprises:

executing an off-line analysis employing parametric data representing operation of the returnless fuel subsystem to develop a system model associated with the returnless fuel subsystem;

employing the system model to determine expected states for electrical current, system pressure, and rotational speed associated with an electrically-powered pump motor of a fuel pump of the returnless fuel subsystem based upon a commanded pump voltage off-board the vehicle; and

determining deviations in the electrical current, system pressure, and rotational speed of the electrically-powered pump motor of the fuel pump off-board the vehicle based upon comparisons of the expected states and the monitored states for the observed parameters.

13. The method of claim 12, wherein the system model determines the expected state for the electrical current based upon a commanded pump voltage off-board the vehicle in accordance with the following relationship:

I_m=a_i(V)P_s+b_i(V)

wherein I_m is expected pump current;

P_s is system pressure;

V is pump voltage; and

a_i and b_i are returnless fuel subsystem-specific scalar values.

14. The method of claim 12, wherein the system model determines an expected state for the rotational speed based upon a commanded pump voltage off-board the vehicle in accordance with the following relationship:

ω

_m=a_ω

(V)P_s+b_ω

(V)

wherein ω

_m is expected pump rotational speed;

P_s is system pressure;

V is pump voltage; and

a_ω

and b_ω

are returnless fuel subsystem-specific scalar values.

15. The method of claim 12, wherein the system model determines an expected state for the system pressure based upon a commanded parameter of pump voltage off-board the vehicle in accordance with the following relationship:

16. The method of claim 9, wherein employing the deviations to determine magnitudes of returnless fuel subsystem operating signatures off-board the vehicle comprises:

developing a plurality of returnless fuel subsystem operating signatures {circumflex over (T)}₁, {circumflex over (T)}₂, and {circumflex over (T)}₃ associated with the observed parameters off-line;

executing a training algorithm that determines a weighting vector for the returnless fuel subsystem operating signatures {circumflex over (T)}₁, {circumflex over (T)}₂, and {circumflex over (T)}₃ associated with specific faults for the returnless fuel subsystem; and

employing the weighting vector for the returnless fuel subsystem operating signatures {circumflex over (T)}₁, {circumflex over (T)}₂, and {circumflex over (T)}₃ and the deviations in the observed parameters to determine said magnitudes of the returnless fuel subsystem operating signatures.

17. The method of claim 16, wherein the operating signature {circumflex over (T)}₁ is associated with a deviation in an electrical current of an electrically-powered pump motor of a fuel pump of the returnless fuel subsystem, the operating signature {circumflex over (T)}₂ is associated with a deviation in the rotational speed of the electrically-powered pump motor of the fuel pump of the returnless fuel subsystem, and the operating signature {circumflex over (T)}₃ is associated with a deviation in a system pressure of the returnless fuel subsystem.

18. The method of claim 16, wherein the returnless fuel subsystem operating signature {circumflex over (T)}₁ is determined in accordance with the following relationship:

{circumflex over (T)}₁=(w₁I_s+w₂Q±

w₃P_s+w₄V+w₅ω

_{m_obs})(Δ

I)

wherein I_s is electrical current;

Q is system mass flow;

P_s is system pressure;

V is system voltage;

ω

_{m_obs} is observed motor speed;

Δ

I is current deviation; and

w=[w₁ w₂ w₃ w₄ w₅] is a weighting vector determined off-line using linear discrimination analysis to achieve separation between a plurality of returnless fuel subsystem faults.

19. The method of claim 18, wherein the returnless fuel subsystem faults include a pressure sensor bias fault, an in-system fuel leak, a blocked fuel filter, and a fault in the windings or commutator of the electrically-powered pump motor of the fuel pump.