Fail operational power system diagnostics

Patent metadata

Field	Value
Publication number	US-9911249-B2
Application number	US-201314017126-A
Country	US
Kind code	B2
Filing date	Sep 3, 2013
Priority date	Sep 20, 2012
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

A method for operating a diagnostic system of a vehicle including a fail operational power system (FOPS) module and a fail operational system (FOS) module includes the FOS module requesting a microcontroller of the FOPS module to generate a diagnostic control signal. The FOS module receives the diagnostic information from a component module of the FOPS module based on the diagnostic control signal generated by the microcontroller. The FOS module executes isolator diagnostics based on the received diagnostic information.

First claim

The invention claimed is:

1. Method for operating a diagnostic system of a vehicle including a fail operational power system (FOPS) module and a fail operational system (FOS) load, comprising:
providing said FOPS module with first and second independent power sources, and first and second parallel power distribution paths, each power distribution path powered by one of said independent power sources;
providing said FOS load with first and second FOS modules, each FOS module respective to one of said first and second power distribution paths;
requesting, at the FOS modules, a microcontroller of the FOPS module to generate a diagnostic control signal;
receiving, at the FOS modules, diagnostic information from a component module of the FOPS module based on the diagnostic control signal generated by the microcontroller; and
executing, at the FOS modules, isolator diagnostics based on the received diagnostic information.

2. The method of claim 1 , wherein the diagnostic information from the component module is received by the FOS module when the microcontroller:
retrieves measured signals stored within the component module using the diagnostic control signal;
extracts the diagnostic information from the measured signals; and
transmits the diagnostic information to the FOS module.

3. Method for operating a diagnostic system of a vehicle including a fail operational power system (FOPS) module and a fail operational system (FOS) module, comprising:
requesting, at the FOS module, a microcontroller of the FOPS module to generate a diagnostic control signal;
receiving, at the FOS module, diagnostic information from a component module of the FOPS module based on the diagnostic control signal generated by the microcontroller; and
executing, at the FOS module, isolator diagnostics based on the received diagnostic information;
wherein the diagnostic information from the component module is received by the FOS module when the microcontroller:
retrieves measured signals stored within the component module using the diagnostic control signal;
extracts the diagnostic information from the measured signals; and
transmits the diagnostic information to the FOS module; and

wherein the diagnostic information received from the component module includes at least one of:
energy signals from each of first and second independent power sources, each of the independent power sources supplying power via respective ones of first and second power distribution paths arranged in parallel to a load;
a first voltage on the first power distribution path monitored by a first voltage detector and a second voltage on the second power distribution path monitored by a second voltage detector; and
a diagnostic status of each of a plurality of switches, the plurality of switches including
a first isolator switch effective when operative in a closed state to power the first power distribution path supplied by the first independent power source,
a second isolator switch effective when operative in a closed state to power the second power distribution path supplied by the second independent power source,
a third isolator switch effective when operative in a closed state to connect the first and second power distribution paths via a connector path,
first and second snub switches configured to snub voltages over a predetermined level from load dumps when a predetermined operating mode requiring fail operational power is enabled, and
a test load switch effective when operative in a closed state to apply a test load to the second independent power source.

4. The method of claim 3 , wherein the energy signals of the first and second power sources are selected from the group consisting of: delivered current, voltage, open circuit voltage, and charging state.

5. The method of claim 3 , wherein the executed isolator diagnostics based on the received diagnostic information comprises:
testing functionality of the first and second snub switches and the test load switch based upon a monitored voltage across each of a plurality of resistors, each resistor respective to one of the first and second snub switches and the test load switch and configured to limit current through the respective ones of the first and second snub switches and the test load switch.

6. The method of claim 3 , wherein the executed isolator diagnostics based on the received diagnostic information comprises:
at least once per ignition cycle, testing functionality of the first and second voltage detectors in conjunction with testing functionality of the third isolator switch.

7. The method of claim 6 , wherein the functionality of the third isolator switch is tested when at least one of:
a monitored current through the third isolator switch is not greater than a current threshold; and
a state of charge of each of the first and second independent power sources is at least a state of charge threshold.

8. The method of claim 3 , wherein the executed isolator diagnostics based on the received diagnostic information comprises:
in response to enabling the predetermined operating mode requiring fail operational power, applying a resistive load drawing a test current for a test duration to test delivered current by the second independent power source; and
periodically applying the restive load drawing the test current until the predetermined operating mode requiring fail operational power is disabled.

9. The method of claim 8 , wherein the second isolator switch is operative in an open state when the resistive load drawing the test current is applied.

10. The method of claim 3 , wherein the executed isolator diagnostics based on the received diagnostic information comprises:
during charging states of the first and second independent power sources once per ignition cycle, separately switching operation of the first and second isolator switches to operation in respective open states for testing functionality.

11. The method of claim 3 , wherein the executed isolator diagnostics based on the received diagnostic information comprises:
alternately switching the first and second isolator switches between open and closed states; and
measuring open circuit voltages of the first and second independent power sources during the alternately switching of the first and second isolator switches.

12. The method of claim 11 , wherein the first and second isolator switches are alternately switched at least once during a Key-OFF event and periodically during a Key-ON event such that the open circuit voltages remain above an open circuit threshold.

13. The method of claim 3 , further comprising:
enabling, at the FOS module, the predetermined operating mode requiring fail operational power based on the received diagnostic information; and
transmitting, at the FOS module, an enable signal to each of the first and second voltage detectors.

14. The method of claim 13 , further comprising:
determining, at the FOS module, a state of health of each of the first and second independent power sources based on the received diagnostic information, wherein the enabling the predetermined operating mode requiring fail operational power is further based upon the state of health of each of the first and second independent power sources.

15. The method of claim 3 , wherein the received diagnostic information from the component module further comprises:
when the predetermined operating mode requiring fail operational power is enabled:
receiving, at the FOS module, predetermined operating mode feedback from the first voltage detector, the predetermined operating mode feedback including one of a normal

Assignees

• Gm Global Tech Operations Llc

Inventors

• Koch David P
• Namuduri Chandra S
• Hoorn Jeffrey James
• Hoskeri Nikhil L
• Hoinka Mark C

Classifications

• G07C5/0808 Primary

  Diagnosing performance data (testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005) · CPC title

• B60R16/0232 Primary

  for measuring vehicle parameters and indicating critical, abnormal or dangerous conditions · CPC title