Electric Vehicle

• US 20130173100A1
• Filed: 12/29/2011
• Published: 07/04/2013
• Est. Priority Date: 12/29/2011
• Status: Active Grant

• Current Assignee: Kawasaki Motors Ltd (Kawasaki Heavy Industries Limited)
• Original Assignee: Kawasaki Jukogyo Kabushiki Kaisha (Kawasaki Heavy Industries Limited)
• Inventors: Takagi, Izumi
• Granted Patent: US 8,965,609 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2200/12 Bikes
• CPC Class Codes: B60L 2200/22 Microcars, e.g. golf cars
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2220/12 Induction machines
• CPC Class Codes: B60L 2220/42 with use of more than one motor
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/14 Acceleration
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/425 Temperature
• CPC Class Codes: B60L 2240/427 Voltage
• CPC Class Codes: B60L 2240/429 Current
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60L 2240/461 Speed
• CPC Class Codes: B60L 2240/463 Torque
• CPC Class Codes: B60L 2240/465 : Slip
• CPC Class Codes: B60L 2240/525 : Temperature of converter or components thereof
• CPC Class Codes: B60L 2240/547 : Voltage
• CPC Class Codes: B60L 2240/549 : Current
• CPC Class Codes: B60L 2240/80 : Time limits
• CPC Class Codes: B60L 2250/20 : by driver identification
• CPC Class Codes: B60L 2250/24 : by lever actuation
• CPC Class Codes: B60L 2250/26 : by pedal actuation
• CPC Class Codes: B60L 2250/28 : Accelerator pedal thresholds
• CPC Class Codes: B60L 2260/26 : Transition between different drive modes
• CPC Class Codes: B60L 2260/28 : Four wheel or all wheel drive
• 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 3/003 : relating to inverters
• CPC Class Codes: B60L 3/0061 : relating to electrical machines
• CPC Class Codes: B60L 3/0084 : relating to control modules
• CPC Class Codes: B60L 50/30 : using propulsion power stored mechanically, e.g. in fly-wheels
• CPC Class Codes: B60L 50/51 : characterised by AC-motors
• CPC Class Codes: B60L 50/61 : by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 50/66 : Arrangements of batteries
• CPC Class Codes: B60L 58/15 : Preventing overcharging
• CPC Class Codes: B60L 7/14 : for vehicles propelled by ac motors
• CPC Class Codes: B60L 7/26 : Controlling the braking effect
• CPC Class Codes: B60W 2530/10 : Weight
• CPC Class Codes: B60W 2720/403 : between front and rear axle
• CPC Class Codes: G05D 17/02 : characterised by the use of electric means
• 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 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles

Abstract

An electric vehicle is presented. The electric vehicle may include a front motor for driving a front wheel; a rear motor for driving a rear wheel; a target torque determiner for determining a target torque of the front motor and a target torque of the rear motor, based on at least a displacement amount of an accelerator operation member operated by a driver; and a motor controller for controlling the front motor and the rear motor to cause the front motor to output the target torque and the rear motor to output the target torque.

Claims

1. An electric vehicle comprising:

a front motor for driving a front wheel;

a rear motor for driving a rear wheel;

a target torque determiner for determining a target torque of the front motor and a target torque of the rear motor, based on at least a displacement amount of an accelerator operation member operated by a driver; and

a motor controller for controlling the front motor and the rear motor to cause the front motor to output the target torque and the rear motor to output the target torque.

2. The electric vehicle according to claim 1,

wherein the target torque determiner is configured to determine the target torque of the front motor and the target torque of the rear motor such that a magnitude of driving torque applied to the front wheel is different from a magnitude of driving torque applied to the rear wheel, according to a vehicle state.

3. The electric vehicle according to claim 2,

wherein the motor controller includes a front motor controller for controlling the front motor, and a rear motor controller for controlling the rear motor;

and

the target torque determiner is configured to determine the target torque of the front motor and the target torque of the rear motor in such a manner that, when one of the front motor controller and the rear motor controller is higher in temperature than the other by a predetermined value or greater, the target torque determiner sets the target torque of the motor controlled by the one of the motor controllers smaller than the target torque of the motor controlled by the other of the motor controllers.

4. The electric vehicle according to claim 2,

wherein the target torque determiner is configured to determine the target torque of the front motor and the target torque of the rear motor based on the vehicle state relating to driving of the electric vehicle.

5. The electric vehicle according to claim 4,

wherein the target torque determiner is configured to determine the target torque of the front motor and the target torque of the rear motor based on at least one of acceleration of the electric vehicle, deceleration of the electric vehicle and a vehicle speed of the electric vehicle.

6. The electric vehicle according to claim 4,

wherein the target torque determiner is configured to determine the target torque of the front motor and the target torque of the rear motor based on how the electric vehicle is turning.

7. The electric vehicle according to claim 4,

wherein the target torque determiner is configured to set the target torque of the rear motor greater when the electric vehicle is driving on an upslope than when the electric vehicle is driving on a level ground.

8. The electric vehicle according to claim 4, further comprising:

a driving distance estimator for estimating a driving distance over which the electric vehicle is able to drive from now;

wherein the target torque determiner is configured to set the target torque of one of the front motor and the rear motor to zero when the driving distance estimated by the driving distance estimator decreases to an amount which is not more than a predetermined distance.

9. The electric vehicle according to claim 1,

wherein the target torque determiner is configured to determine the target torque of the front motor and the target torque of the rear motor during deceleration of the electric vehicle such that the target torque of at least one of the front motor and the rear motor is set to a negative value to cause the at least one of the front motor and the rear motor to be in a regenerative braking mode, and an absolute value of the target torque of the front motor is different from an absolute value of the target torque of the rear motor according to the vehicle state.

10. The electric vehicle according to claim 9,

wherein the target torque determiner is configured to determine the target torque of the front motor and the target torque of the rear motor such that the target torque of the rear motor is set to a negative value and an absolute value of the target torque of the rear motor is greater, to make regenerative braking torque of the rear motor greater when the electric vehicle is decelerated on a downslope than when the electric vehicle is decelerated on a level ground.

11. The electric vehicle according to claim 1,

wherein the front motor is configured to drive the front wheel via a differential gear mechanism and the rear motor is configured to drive the rear wheel via a differential gear mechanism.

12. The electric vehicle according to claim 1,

wherein the front wheel is attached with a balloon tire and the rear wheel is attached with a balloon tire.

13. The electric vehicle according to claim 4, further comprising:

a slip detector for detecting a slip state of one of the front wheel and the rear wheel;

wherein the target torque determiner is configured to set a target torque of one of the front motor and the rear motor which drives the wheel which is slipping smaller than a target torque of the other of the front motor and the rear motor which drives the wheel which is not slipping, based on the wheel slip state detected by the slip detector.