Fault diagnosing apparatus for vehicle and fault diagnosing method for vehicle

• US 20060224360A1
• Filed: 03/08/2006
• Published: 10/05/2006
• Est. Priority Date: 03/30/2005
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kishimoto, Takeshi
• Granted Patent: US 7,269,535 B2
• Time in Patent Office: Days
• US Class Current: 702/183
• CPC Class Codes: B60L 2210/10 DC to DC converters
• 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: B60L 50/15 with additional electric power supply with capacitors charged by engine-driven generators B60L50/40; with batteries charged by engine-driven generators B60L50/61
• CPC Class Codes: H02H 3/044 Checking correct functioning of protective arrangements, e.g. by simulating a fault for differential current circuit breakers H02H3/335
• CPC Class Codes: H02H 9/001 limiting speed of change of electric quantities, e.g. soft switching on or off progressive control of electronic switches for eliminating interferences H03K17/16
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A vehicle includes a direct current power supply, an electric circuit such as a DC/DC converter supplied with a current from the direct current power supply, a connecting portion that includes a plurality of relays and that connects and disconnects a path supplying the current from the direct current power supply to the electric circuit, and a voltage sensor monitoring the path between the connecting portion and the electric circuit. A control portion provides control to connect and disconnect the connecting portion. The control portion brings part of the plurality of relays into conduction to make a provisional determination of conduction fault of a relay that is to be non-conductive in accordance with an output of the sensing portion, and when a result of the provisional determination indicates fault, the control portion stores the output of the voltage sensor as a first value and provides control to once bring part of the relays out of conduction and bring the part of the relays into conduction, and thereafter compares the first value and the output of the voltage sensor to determine whether or not to confirm the provisional determination. Thus, a fault diagnosing apparatus and a fault diagnosing method which reduce a time for a fault diagnosis can be provided.

Claims

1. A fault diagnosing apparatus for a vehicle,

said vehicle including

a direct current power supply,

an electric circuit supplied with a current from said direct current power supply,

a connecting portion that includes a plurality of relays and that connects and disconnects a path supplying the current from said direct current power supply to said electric circuit, and

a sensing portion monitoring the path between said connecting portion and said electric circuit;

wherein

said fault diagnosing apparatus comprises a control portion providing control to connect and disconnect said connecting portion, wherein

said control portion brings part of said plurality of relays into conduction to make a provisional determination of conduction fault of a relay that is to be non-conductive in accordance with an output of said sensing portion, and when a result of said provisional determination indicates fault, said control portion stores the output of said sensing portion as a first value and provides control to once change a state of at least one of said plurality of relays and to return the changed state back, and thereafter compares said first value and the output of said sensing portion to determine whether or not to confirm said provisional determination.

2. The fault diagnosing apparatus for a vehicle according to claim 1, wherein

one of said plurality of relays is a first relay connecting a positive electrode side of said direct current power supply to said electric circuit, and

another one of said plurality of relays is a second relay connecting a negative electrode side of said direct current power supply to said electric circuit.

3. The fault diagnosing apparatus for a vehicle according to claim 1, wherein

said vehicle further includes

a capacitor smoothing a voltage applied from said connecting portion to said electric circuit,

said sensing portion includes

a voltage sensor sensing a voltage between terminals of said capacitor, and

said controlling portion allows said electric circuit to operate to discharge said capacitor, and thereafter makes said provisional determination.

4. The fault diagnosing apparatus for a vehicle according to claim 3, wherein

said controlling portion confirms said provisional determination when a voltage value indicated by an output of said sensing portion is increased from a voltage value indicated by said first value when said part of said plurality of relays are again brought into conduction.

5. A fault diagnosing method for a vehicle,

said vehicle including

a direct current power supply,

an electric circuit supplied with a current from said direct current power supply,

a connecting portion that includes a plurality of relays and that connects and disconnects a path supplying the current from said direct current power supply to said electric circuit, and

a sensing portion monitoring the path between said connecting portion and said electric circuit;

wherein said fault diagnosing method comprises the steps of;

bringing part of said plurality of relays into conduction to make a provisional determination of conduction fault of a relay that is to be non-conductive in accordance with an output of said sensing portion;

when a result of said provisional determination indicates fault, storing the output of said sensing portion as a first value;

when the result of said provisional determination indicates fault, providing control to once change a state of at least one of said plurality of relays and to return the changed state back; and

comparing said first value and the output of said sensing portion to determine whether or not to confirm said provisional determination.

6. The fault diagnosing method for a vehicle according to claim 5, wherein

one of said plurality of relays is a first relay connecting a positive electrode side of said direct current power supply to said electric circuit, and

another one of said plurality of relays is a second relay connecting a negative electrode side of said direct current power supply to said electric circuit.

7. The fault diagnosing method for a vehicle according to claim 5, wherein

said vehicle further includes

a capacitor smoothing a voltage applied from said connecting portion to said electric circuit,

said sensing portion includes

a voltage sensor sensing a voltage between terminals of said capacitor, and

said fault diagnosing method further includes a step of, prior to the step of making a provisional determination, allowing said electric circuit to operate to discharge said capacitor.

8. The fault diagnosing method for a vehicle according to claim 7, wherein

said fault diagnosing method confirms said provisional determination when a voltage value indicated by an output of said sensing portion is increased from a voltage value indicated by said first value in said step of determining whether or not to confirm said provisional determination.