Hybrid vehicle and control method thereof

• US 8,909,399 B2
• Filed: 05/25/2009
• Issued: 12/09/2014
• Est. Priority Date: 05/25/2009
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kato, Norihiko, Kamichi, Kensuke, Yamamoto, Masaya
• Primary Examiner(s): Nguyen, John Q
• Assistant Examiner(s): WHALEN, MICHAEL F
• Application Number:
  US13/322,340
• Publication Number:
  US 20120072066A1
• Time in Patent Office: 2,024 Days
• Field of Search: 180/65.21, 180/65.265, 180/65.28, 180/65.285, 180/65.29, 903/902, 903/903, 903/906, 903/930, 701/22
• US Class Current: 701/22
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/52 Driving a plurality of drive axles, e.g. four-wheel drive
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/60 using power supplied by batteries in combination with fuel cells B60L50/75
• CPC Class Codes: B60L 53/00 Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
• CPC Class Codes: B60W 10/06 including control of combustion engines
• 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 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2540/16 Ratio selector position
• CPC Class Codes: B60W 2710/244 Charge state
• CPC Class Codes: F16H 2037/0866 Power split variators with distributing differentials, with the output of the CVT connected or connectable to the output shaft
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• 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
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y10S 903/93 : Conjoint control of different elements

Abstract

In the case that the motor travel priority mode is set and the restriction mode is set as the control mode because of the request of the operation of the engine, the threshold value Peg that is smaller value between the obtained value (kw·Wout) from multiplying the output limit Wout of the battery by the preset conversion factor kw and the preset power Pset that is smaller than the converted output limit Wout of the battery at a normal time is compared with the driving power Pdrv*. The hybrid vehicle is driven with the motor travel in idle operation of the engine when the driving power Pdrv* is not more than the threshold value Peg, and the hybrid vehicle is driven with power from the engine when the driving power Pdrv* is more than the threshold value Peg.

Claims

1. A hybrid vehicle, having an internal combustion engine capable of outputting power for driving the hybrid vehicle, a motor constructed to input and output power for driving the hybrid vehicle, and a secondary battery designed to transmit electric power to and from the motor, the hybrid vehicle being capable of motor travel where the hybrid vehicle is driven only with input and output power to and from the motor and hybrid travel where the hybrid vehicle is driven with output power from the internal combustion engine regardless of charge and discharge of the battery, the hybrid vehicle comprising:

a charger connected to an external power supply in a system-off state of the hybrid vehicle to charge the secondary battery with electric power from the external power supply;

a driving power setting module that sets a driving power required for driving the hybrid vehicle;

an accumulated charge ratio calculation module that calculates an accumulated charge ratio based on a state of the secondary battery, the accumulated charge ratio being a ratio of an accumulated charge amount in the secondary battery to a whole capacity of the secondary battery;

an output limit setting module that sets an output limit of the secondary battery as a maximum allowable electric power to be output from the secondary battery based on the state of the secondary battery;

a mode setting module that, in a case that the calculated accumulated charge ratio is at least more than or equal to a first preset ratio upon system-on of the hybrid vehicle, sets a motor travel priority mode where the motor travel is prioritized for driving the hybrid vehicle until the calculated accumulated charge ratio becomes less than a second preset ratio that is less than the first preset ratio during vehicle traveling, while setting a hybrid travel priority mode where the hybrid travel is prioritized for driving the hybrid vehicle in a case that the motor travel priority mode is not set; and

a control module that, in a case that the motor travel priority mode is set and a preset condition for restricting the motor travel is not satisfied, controls the motor so that the hybrid vehicle is driven with the motor travel when the set driving power is not more than the set output limit of the secondary battery, while controlling the internal combustion engine and the motor so that the hybrid vehicle is driven with the hybrid travel when the set driving power is more than the set output limit of the secondary battery, and

in a case that the motor travel priority mode is set and the preset condition is satisfied, the control module controlling the motor so that the hybrid vehicle is driven with the motor travel when the set driving power is not more than a threshold power that is a smaller power between the set output limit of the secondary battery and a predetermined power, while controlling the internal combustion engine and the motor so that the hybrid vehicle is driven with the hybrid travel when the set driving power is more than the threshold power,

wherein the control module, in the case that the motor travel priority mode is set and the preset condition is satisfied on condition that the set driving power is more than the threshold power, controls the internal combustion engine and the motor so that the hybrid vehicle is driven with the hybrid travel and the set driving power is output from the internal combustion engine when the set driving power is able to be output from the internal combustion engine, while controlling the internal combustion engine and the motor so that the hybrid vehicle is driven with the hybrid travel and the set driving power is output from the internal combustion engine together with the motor when the set driving power is not able to be output from the internal combustion engine, wherein the preset condition is a condition that an operation of the internal combustion engine is requested, and the control module, in the case that the motor travel priority mode is set an the preset condition is satisfied on condition that the set driving poser is not more than the threshold power, controls the internal combustion engine and the motor so that the hybrid vehicle is driven with the motor travel and the internal combustion is in idle operation.

2. The hybrid vehicle in accordance with claim 1, wherein the preset condition is a condition that is satisfied when any one of three conditions is satisfied, a condition for operating the internal combustion engine to heat a cabin, a condition for operating the internal combustion engine to heat a catalyst of a catalytic conversion unit attached to an exhaust system of the internal combustion engine, and a condition for operating the internal combustion engine to warm up the internal combustion engine.

3. The hybrid vehicle in accordance with claim 1, wherein the predetermined power is a power that, when performing the motor travel for a preset distance with, the accumulated charge ratio becomes the second preset ratio from a fully charged state of the secondary battery.

4. The hybrid vehicle in accordance with claim 1, wherein the control module, in a case that the hybrid travel priority mode is set and a prohibition condition for prohibiting discharge from the secondary battery is satisfied, controls the internal combustion engine so that the hybrid vehicle is driven only with output power from the internal combustion engine.

5. The hybrid vehicle in accordance with claim 4, the prohibition condition is a condition that is satisfied when any one of three conditions is satisfied, a condition for performing forced charge of the secondary battery, a condition that a defroster switch is on for ensuring driver'"'"'s visibility, and a condition that the set output limit of the secondary battery is not more than a preset limit predetermined as an extremely smaller value than ordinary values.

6. The hybrid vehicle in accordance with claim 1, wherein the hybrid vehicle further comprising:

a generator constructed to input and output power and transmit electric power to and from the secondary battery; and

a planetary gear mechanism with three elements each connected to three shafts, an output shaft of the internal combustion engine, a rotating shaft of the generator, and a driveshaft linked to an axle of the hybrid vehicle,

wherein the control module controls the generator for operation control of the internal combustion engine.

7. A control method of a hybrid vehicle having an internal combustion engine capable of outputting power for driving the hybrid vehicle, a motor constructed to input and output power for driving the hybrid vehicle, a secondary battery designed to transmit electric power to and from the motor, and a charger connected to an external power supply in a system-off state of the hybrid vehicle to charge the secondary battery with electric power from the external power supply, the hybrid vehicle being capable of motor travel where the hybrid vehicle is driven only with input and output power to and from the motor and hybrid travel where the hybrid vehicle is driven with output power from the internal combustion engine regardless of charge and discharge of the battery, the control method comprising:

in a case that a motor travel priority mode where the motor travel is prioritized for driving the hybrid vehicle is set and a preset condition for restricting the motor travel is not satisfied, controlling the motor so that the hybrid vehicle is driven with the motor travel when a driving power required for driving the hybrid vehicle is not more than an output limit of the secondary battery as a maximum allowable electric power to be output from the secondary battery, while controlling the internal combustion engine and the motor so that the hybrid vehicle is driven with the hybrid travel when the driving power is more than the output limit of the secondary battery, and

in a case that the motor travel priority mode is set and the preset condition is satisfied, controlling the motor so that the hybrid vehicle is driven with the motor travel when the driving power is not more than a threshold power that is a smaller power between the output limit of the secondary battery and a predetermined power, while controlling the internal combustion engine and the motor so that the hybrid vehicle is driven with the hybrid travel when the driving power is more than the threshold power,

wherein the motor travel priority mode is set according to an accumulated charge ratio being at least more than or equal to a first preset ratio upon system-on of the hybrid vehicle until the accumulated charge ratio becomes less than a second preset ratio that is less than the first preset ratio during vehicle traveling, the accumulated charge ratio being a ratio of an accumulated charge amount in the secondary battery to a whole capacity of the secondary battery,

wherein the control method, in the case that the motor travel priority mode is set and the preset condition is satisfied on condition that the driving power is more than the threshold power, controlling the internal combustion engine and the motor so that the hybrid vehicle is driven with the hybrid travel and the driving power is output from the internal combustion engine when the driving power is able to be output from the internal combustion engine, while controlling the internal combustion engine and the motor so that the hybrid vehicle is driven with the hybrid travel and the driving power is output from the internal combustion engine together with the motor when the driving power is not able to be output from the internal combustion engine, wherein the preset condition is a condition that an operation of the internal combustion engine is requested, and the control method, in the case that the motor travel priority mode is set an the preset condition is satisfied on condition that the set driving poser is not more than the threshold power, controls the internal combustion engine and the motor so that the hybrid vehicle is driven with the motor travel and the internal combustion is in idle operation.

8. The control method of the hybrid vehicle in accordance with claim 7, wherein the control method, in a case that the hybrid travel priority mode is set and a prohibition condition for prohibiting discharge from the secondary battery is satisfied, controlling the internal combustion engine so that the hybrid vehicle is driven only with output power from the internal combustion engine.