Control device for electric vehicle and control method for electric vehicle

Patent metadata

Field	Value
Publication number	US-9931962-B2
Application number	US-201415021241-A
Country	US
Kind code	B2
Filing date	Sep 10, 2014
Priority date	Sep 24, 2013
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

Provided are a control device for an electric vehicle and a control method for an electric vehicle capable of appropriately suppressing a vibration. In the control device for an electric vehicle according to the present invention, when a torque is controlled that is generated by a motor configured to generate a torque for braking or driving a drive wheel via a speed reduction mechanism and a drive shaft coupled to the speed reduction mechanism, the torque generated by the motor is controlled based on a rotational torque command value based on an accelerator operation or a brake operation by a driver, and a vibration suppression control torque command value for suppressing a vibration component caused by a resonance of the vehicle. Then, when a predetermined condition is satisfied, the torque generated by the motor is reduced.

First claim

The invention claimed is:

1. A control device for an electric vehicle including a motor configured to generate a torque for braking or driving a drive wheel via a speed reduction mechanism and a drive shaft coupled to the speed reduction mechanism, the control device comprising:
a torque command value calculation unit configured to calculate a rotational torque command value directed to the motor based on an accelerator operation or a brake operation by a driver;
a vibration suppression control torque calculation unit configured to calculate, in order to suppress a vibration component caused by resonance of the vehicle, a vibration suppression control torque command value based on a rotational variation of the motor;
a motor control unit configured to control, based on the rotational torque command value and the vibration suppression control torque command value, the torque generated by the motor;
a vehicle stop state determination unit configured to determine a vehicle stop state; and
a shift range detection unit configured to detect a shift range of the vehicle,
wherein the motor control unit is further configured to reduce the vibration suppression control torque command value regardless of the rotational variation of the motor, after determining, in a drive range in which a creep torque is generated, that the vehicle is in the vehicle stop state, and thereafter the shift range is shifted from the drive range to a parking range or a neutral range, and thereafter a vibration suppression control torque is applied for a predetermined period.

2. The control device for an electric vehicle according to claim 1 , wherein the motor control unit is further configured to set the vibration suppression control torque command value to zero when reducing the vibration suppression control torque.

3. A control device for an electric vehicle including a motor configured to generate a torque for braking or driving a drive wheel via a speed reduction mechanism and a drive shaft coupled to the speed reduction mechanism, the control device comprising:
a torque command value calculation unit configured to calculate a rotational torque command value directed to the motor based on an accelerator operation or a brake operation by a driver;
a vibration suppression control torque command value calculation unit configured to calculate, in order to suppress a vibration component caused by resonance of the vehicle, a vibration suppression control torque command value based on a rotational variation of the motor;
a motor control unit configured to control the motor based on the rotational torque command value and the vibration suppression control torque command value;
a shift range detection unit configured to detect a shift range of the vehicle;
a zero torque determination unit configured to determine, based on the rotational torque command value, whether or not the shift range is shifted from a drive range to a parking range or a neutral range and the torque generated by the motor becomes zero after the vehicle is stopped in a drive range in which a creep torque is generated; and
a vibration suppression control torque command value decrease unit configured to decrease, after a predetermined period elapses since the zero torque determination unit determines that the torque is in a zero state, the vibration suppression control torque command value, regardless of the rotational variation of the motor.

4. A control method for an electric vehicle including a motor that is coupled to a drive wheel via a speed reduction mechanism and a drive shaft, and is configured to generate a braking torque or a driving torque on the drive wheel, and a motor controller in communication with the motor and configured to carry out torque control, the control method comprising:
controlling, by the motor controller, the motor based on a rotational torque command value, the rotational torque command value being determined based on an accelerator operation or a brake operation by a driver, and a vibration suppression control torque command value to suppress a vibration component caused by resonance of the vehicle; and
decreasing, by the motor controller, the vibration suppression control torque command value after a predetermined period elapses since the rotational torque command value decreases due to switching of a shift range from a drive range to a neutral range or a parking range after the vehicle is stopped.

Assignees

• Hitachi Automotive Systems Ltd

Inventors

• Suzuki Keisuke
• Kobayashi Hitoshi
• Yamamoto Tatsuyuki

Classifications

• B60L3/102

  of individual wheels · CPC title

• B60L3/0061 Primary

  relating to electrical machines · CPC title

• B60L15/2045

  for optimising the use of energy · CPC title

• B60L2240/421

  Speed · CPC title

• B60L3/12

  Recording operating variables {; Monitoring of operating variables} · CPC title