Electric vehicle control system

Patent metadata

Field	Value
Publication number	US-2016200324-A1
Application number	US-201414914365-A
Country	US
Kind code	A1
Filing date	Aug 8, 2014
Priority date	Aug 30, 2013
Publication date	Jul 14, 2016
Grant date	—

Abstract

Provided is an electric vehicle control system capable of securing good response and slip stopping property with respect to changes in a road surface condition. The system includes a vehicle controller configured to calculate a driver's demand torque command value according to a driver's accelerating or braking operation, a first communication device capable of communicating between a hydraulic controller and a motor controller, and a second communication device capable of communicating between the vehicle controller and the motor controller. The system includes a control system in which the hydraulic controller transmits a motor torque command value to the motor controller through the first communication device; the vehicle controller transmits the driver's demand torque command value to the motor controller through the second communication device; and the motor controller selects either one of the received motor torque command value and the received driver's demand torque command value as the command value.

First claim

1 . An electric vehicle control system comprising:
a wheel velocity calculation unit configured to calculate velocities of wheels; an electric motor configured to generate a driving/braking force on the wheels; a hydraulic braking device configured to generate a hydraulic braking force on the wheels; a motor controller configured to control the electric motor according to a command value; a hydraulic controller configured to calculate the braking force to be generated on the wheels by using the calculated wheel velocities and control the hydraulic braking device so as to generate the calculated braking force; a vehicle controller configured to calculate a driver's demand torque command value according to a driver's accelerating or braking operation; a first communication device configured to communicate between the hydraulic controller and the motor controller; and a second communication device configured to communicate between the vehicle controller and the motor controller, the electric vehicle control system being provided with a control system in which: the hydraulic controller calculates a motor torque command value as the command value for generating a driving/braking force in the electric motor according to the calculated wheel velocities; the hydraulic controller transmits the motor torque command value to the motor controller through the first communication device; the vehicle controller transmits the driver's demand torque command value to the motor controller through the second communication device; and the motor controller selects either one of the received motor torque command value and the received driver's demand torque command value as the command value for generating the driving/braking force in the electric motor.

2 . The electric vehicle control system of claim 1 , wherein:
the motor controller transmits information about the selected command value to the vehicle controller through the first communication device.

3 . The electric vehicle control system of claim 1 , wherein:
the vehicle controller includes a control system abnormality judgment unit configured to judge abnormality of the control system on the basis of the selected command value which has been received, a control state of the vehicle, and the driver's demand torque command value.

4 . The electric vehicle control system of claim 3 , wherein:
the control system abnormality judgment unit includes a hydraulic braking device abnormality judgment unit configured to make a judgment as to whether a hydraulic braking device is abnormal as the control state of the vehicle, and an acceleration slip control state judgment unit configured to make a judgment as to whether acceleration slip control is in operation as the control state of the vehicle and a deceleration slip control state judgment unit configured to make a judgment as to whether deceleration slip control is in operation as the control state of the vehicle.

5 . The electric vehicle control system of claim 4 , wherein:
the control system abnormality judgment unit determines that there is abnormality when the driver's demand torque is smaller than the selected command value if the judged state of the hydraulic braking device is normal, and the acceleration slip control is in operation.

6 . The electric vehicle control system of claim 4 , wherein:
the control system abnormality judgment unit determines that there is abnormality when the driver's demand torque is larger than the selected command value if the judged state of the hydraulic braking device is normal, and the deceleration slip control is in operation.

7 . The electric vehicle control system of claim 4 , wherein:
the control system abnormality judgment unit determines that there is abnormality when difference between the driver's demand torque and the selected command value is equal to or larger than a predetermined value if the judged state of the hydraulic braking device is normal and neither the acceleration slip control nor the deceleration slip control is in operation, or if the judged state of the hydraulic braking device is abnormal.

8 . The electric vehicle control system of claim 1 , wherein:
the first communication device and the second communication device are CAN communication.

9 . The electric vehicle control system of claim 8 , wherein:
the CAN communication includes a first CAN bus, a second CAN bus arranged in parallel to the first CAN bus, and a connection bus connecting the first CAN bus and the second CAN bus to each other; and the vehicle controller is interposed in the connection bus, and the motor controller and the hydraulic controller are connected to the first CAN bus.

10 . The electric vehicle control system of claim 8 , comprising an electric power steering device and a velocity meter control device, wherein:
the first CAN bus is connected to a component for driving the electric motor, and the second CAN bus is connected to the power steering device and a velocity meter device; the hydraulic controller transmits information of the calculated wheel velocities to the first CAN bus; and the power steering device and a velocity meter receive the transmitted information of the wheel velocities from the second CAN bus via the vehicle controller.

11 . The electric vehicle control system of claim 8 , wherein:
the CAN communication includes a first CAN bus, a second CAN bus arranged in parallel to the first CAN bus, and first and second connection buses connecting the first and second CAN buses to each other; the first connection bus is connected to the vehicle controller, and the second connection bus is connected to the hydraulic controller; the first CAN bus is connected to the motor controller and a component for driving the electric motor; the second CAN bus is connected to the power steering device and a velocity meter; the hydraulic controller transmits the calculated wheel velocities to the second connection bus; and the power steering device and a velocity meter device receive the transmitted information of the wheel velocities from the second CAN bus via the second connection bus.

12 . The electric vehicle control system of claim 8 , wherein:
the CAN communication includes a first CAN bus, a second CAN bus arranged in parallel to the first CAN bus, and first and second connection buses connecting the first and second CAN buses; the first connection bus is connected to the vehicle controller, and the second connection bus is connected to the motor controller; the first CAN bus is connected to a component for driving the electric motor; the second CAN bus is connected to the hydraulic controller, the power steering device, and a velocity meter; and the hydraulic controller transmits information of the calculated wheel velocities to the second CAN bus, and the power steering device and the velocity meter receive the transmitted information of the wheel velocities from the second CAN bus.

13 . An electric vehicle control system comprising:
a vehicle controller configured to calculate a driver's demand torque command value according to a driver's accelerating or braking operation; a motor controller configured to control an electric motor which generates a driving/braking force according to a command value; and an actuator controller configured to calculate a vehicle demand torque command value according to vehicle behavior and control an actuator installed in the vehicle, wherein: the motor controller controls the electric motor according to the driver's demand torque command value from the vehicle controller and the vehicle demand torque command value from the actuator controlle

Assignees

• Hitachi Automotive Systems Ltd

Inventors

• Suzuki Keisuke
• Kobayashi Hitoshi
• Yamamoto Tatsuyuki

Classifications

• B60W10/184

  with wheel brakes · CPC title

• B60L2250/26

  by pedal actuation · CPC title

• B60L7/18

  Controlling the braking effect (B60L7/12, B60L7/14, B60L7/16 take precedence) · CPC title

• B60L15/2009 Primary

  for braking · CPC title

• B60L3/12

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