Control device for vehicle and method of controlling vehicle

• US 9,302,671 B2
• Filed: 06/11/2013
• Issued: 04/05/2016
• Est. Priority Date: 07/27/2012
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Yamazaki, Takehiko
• Primary Examiner(s): BUTLER, RODNEY ALLEN
• Application Number:
  US14/416,218
• Publication Number:
  US 20150210271A1
• Time in Patent Office: 1,029 Days
• US Class Current: 1/1
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60K 6/543 the transmission being a continuously variable transmission
• CPC Class Codes: B60L 1/00 Supplying electric power to auxiliary equipment of vehicles circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: B60L 2250/10 by alarm
• CPC Class Codes: B60L 3/00 Electric devices on electrically-propelled vehicles for safety purposes; Monitoring operating variables, e.g. speed, deceleration or energy consumption methods or circuit arrangements for monitoring or controlling batteries or fuel cells B60L58/00
• CPC Class Codes: B60L 3/0092 with use of redundant elements for safety purposes
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 50/10 using propulsion power supplied by engine-driven generators, e.g. generators driven by combustion engines
• CPC Class Codes: B60L 58/10 for monitoring or controlling batteries
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• 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: B60W 30/18127 Regenerative braking
• CPC Class Codes: F02D 2041/227 Limping Home, i.e. taking specific engine control measures at abnormal conditions
• CPC Class Codes: F02N 11/006 using a plurality of electric motors
• CPC Class Codes: F02N 11/04 the motors being associated with current generators
• CPC Class Codes: F02N 11/0814 comprising means for controlling automatic idle-start-stop
• CPC Class Codes: F02N 11/0866 comprising several power sources, e.g. battery and capacitor or two batteries
• CPC Class Codes: F02N 11/087 : Details of the switching means in starting circuits, e.g. relays or electronic switches
• CPC Class Codes: F02N 11/108 : for diagnosis of the starter or its components
• CPC Class Codes: F02N 2011/0896 : Inverters for electric machines, e.g. starter-generators
• CPC Class Codes: F02N 2200/0801 : Vehicle speed
• CPC Class Codes: F02N 2250/02 : Battery voltage drop at start, e.g. drops causing ECU reset
• CPC Class Codes: G01R 31/006 : on road vehicles, e.g. automobiles or trucks testing of ignition installations peculiar to internal combustion engines F02P17/00
• CPC Class Codes: G01R 31/3278 : of relays, solenoids or reed switches measuring contact resistance G01R27/205; high voltage magnetic switches G01R31/3271, G01R31/333; testing electric windings G01R31/72; monitoring of fail safe circuits H01H47/002
• CPC Class Codes: H02J 7/0048 : Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/1423 : with multiple batteries
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• 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: Y10S 903/93 : Conjoint control of different elements

Abstract

A control device for a vehicle includes a relay adapted to switch whether a first battery electrically connected to a motor generator and a second battery electrically connected to an electric load of the vehicle are to be electrically connected or not by turning on/off the relay. The relay is turned off during a power operation of the motor generator to disconnect an electric connection between the first battery and the second battery. The relay is turned on during a regenerative operation of the motor generator to electrically connect the first battery and the second battery. In a case where an on-fixation failure of the relay is detected, the power operation of the motor generator is prohibited.

Claims

1. A control device for a vehicle, comprising:

a motor generator mechanically connected to an output shaft of an engine;

a first battery electrically connected to the motor generator;

a second battery electrically connected to an electric load of the vehicle;

first and second relays adapted to respectively switch to cause the first battery and the second battery to be electrically connected or not, by turning the respective relay on or off; and

a controller electrically connected to each of the motor generator, the first and second batteries, and the first and second relays, and configured to cause the motor generator to carry out a power operation or a regenerative operation in accordance with an operation state of the vehicle,

wherein the controller is configured to;

turn off the first and second relays during the power operation of the motor generator so as to disconnect an electric connection between the first battery and the second battery, and

turn on one relay of the first and second relays during the regenerative operation of the motor generator so as to electrically connect the first battery and the second battery,

wherein the controller is configured to detect an on-fixation failure in which the relay is fixed in an on state on the basis of a state of the second battery when a command to turn off the first relay and the second relay is outputted by the controller, and

wherein the controller is configured to prohibit the power operation of the motor generator in a case where the on-fixation failure of any of the first and the second relays is detected.

2. The control device for the vehicle according to claim 1,

wherein

the controller is configured to detect an off-fixation failure in which the first relay or the second relay is fixed in an off state on the basis of a voltage difference between the first battery and the second battery when a command to turn on the first relay or second relay is outputted by the controller,

wherein the controller is configured to turn on one relay of the first relay and the second relay in which an off-fixation failure has not been detected in a case where the off-fixation failure is detected in any one of the first relay and the second relay, and

wherein the controller is configured to prohibit the power operation of the motor generator in a case where the off-fixation failure of any of the first and the second relays is detected.

3. The control device according to claim 1,

wherein the controller is configured to determine that the on-fixation failure occurs in a case where a condition (i) is satisfied when a power steering and a vehicle dynamic control are not operated:

(i) a predetermined period of time has elapsed in a state in which the voltage of the second battery is a predetermined voltage or lower and a discharge current flows from the second battery.

4. The control device according to claim 2,

wherein the controller is configured to determine that the off-fixation failure occurs in a case where a condition (ii) or (iii) is satisfied:

(ii) a first predetermined period of time has elapsed in a state that the voltage difference between the first battery and the second battery is a first predetermined voltage or higher and a discharge current flows from the second battery;

(iii) a second predetermined period of time shorter than the first predetermined period of time has elapsed in a state that the voltage difference between the first battery and the second battery is a second predetermined voltage or higher and a discharge current flows from the second battery, the second predetermined voltage being higher than the first predetermined voltage.

5. A method of controlling a vehicle, the vehicle comprising:

a motor generator mechanically connected to an output shaft of an engine;

a first battery electrically connected to the motor generator;

a second battery electrically connected to an electric load of the vehicle; and

first and second relays adapted to respectively switch to cause the first battery and the second battery to be electrically connected or not by turning the corresponding relay on or off,

wherein the method comprises;

turning off the first and second relays during power operation of the motor generator so as to disconnect an electric connection between the first battery and the second battery, and turning on one relay of the first and second relays during regenerative operation of the motor generator so as to electrically connect the first battery and the second battery;

detecting an on-fixation failure in which the relay is fixed in an on state on the basis of a state of the second battery when a command to turn off the first relay and the second relay is outputted; and

prohibiting the power operation of the motor generator in a case where the on-fixation failure of any of the first and the second relays is detected.

6. The method according to claim 5, further comprising:

detecting an off-fixation failure in which the first relay or the second relay is fixed in an off state on the basis of a voltage difference between the first battery and the second battery when a command to turn on the first relay or second relay is outputted;

turning on one relay of the first relay and the second relay in which an off-fixation failure has not been detected in a case where the off-fixation failure is detected in any one of the first relay and the second relay; and

prohibiting the power operation of the motor generator in a case where the off-fixation failure of any of the first and the second relays is detected.