Control apparatus and control method of vehicle

• US 9,884,568 B2
• Filed: 10/15/2014
• Issued: 02/06/2018
• Est. Priority Date: 10/18/2013
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Niimi, Yoshitaka, Ang, Wanleng, Okamura, Masaki, Tsujii, Shintaro, Morisaki, Keisuke, Yaguchi, Hideaki
• Primary Examiner(s): Elchanti, Hussein
• Application Number:
  US15/029,858
• Publication Number:
  US 20160250946A1
• Time in Patent Office: 1,210 Days
• CPC Class Codes: B60K 28/16 responsive to, or preventing, skidding of wheels brake control systems for vehicle drive stability B60T8/1755; arrangements responsive to a speed condition for adjusting wheel braking force B60T8/32; control of vehicle driving stability otherwise than by controlling the propulsion unit only B60W30/02; preventing wheel slippage by reducing power in rail vehicles B61C15/00
• 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 15/2018 for braking on a slope
• CPC Class Codes: B60L 2240/465 Slip
• CPC Class Codes: B60L 2260/10 Temporary overload
• CPC Class Codes: B60L 2260/26 Transition between different drive modes
• CPC Class Codes: B60L 3/0076 relating to braking
• CPC Class Codes: B60L 3/10 Indicating wheel slip ; Correction of wheel slip
• CPC Class Codes: B60L 3/102 of individual wheels
• CPC Class Codes: B60L 3/106 for maintaining or recovering the adhesion of the drive wheels
• CPC Class Codes: B60L 3/108 whilst braking, i.e. ABS
• CPC Class Codes: B60L 7/003 Dynamic electric braking by short circuiting the motor
• CPC Class Codes: B60T 2201/04 Hill descent control
• CPC Class Codes: B60T 8/885 using electrical circuitry
• CPC Class Codes: B60W 30/18172 Preventing, or responsive to skidding of wheels
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A control apparatus for a vehicle including a three-phase AC motor and a power converter, the control apparatus includes an ECU. The ECU is configured to determine whether a rotation speed of the three-phase AC motor is equal to or less than a predetermined threshold and whether a stopping operation of the vehicle is performed, to determine that the vehicle stops when the rotation speed is equal to or less than the predetermined threshold and the stopping operation is performed, to determine whether the vehicle skids, and to switch a state of the power converter to a state where all on one side of the first and second switching elements are turned off and at least one on the other side of the first and second switching elements is turned on when the ECU determines that the vehicle stops and that the vehicle does not skid.

Claims

1. A control apparatus for a vehicle, the vehicle including a three-phase AC motor and a power converter, the three-phase AC motor being driven at a rotation speed synchronized with a rotation speed of a drive shaft of the vehicle, and the power converter including a first switching element and a second switching element, which are connected in series to each other, for each of three phases of the three-phase AC motor and being configured to convert electric power supplied to the three-phase AC motor from DC power to AC power, the control apparatus comprising

an electronic control unit configured to:

determine whether the rotation speed of the three-phase AC motor is equal to or less than a predetermined threshold value and whether a stopping operation that stops the vehicle is performed;

determine that the vehicle stops when the rotation speed of the three-phase AC motor is equal to or less than the predetermined threshold value and the stopping operation is performed;

determine whether the vehicle skids; and

switch a state of the power converter to a state where all on one side of the first switching elements and the second switching elements are turned off and at least one on the other side of the first switching elements and the second switching elements is turned on when the electronic control unit determines that the vehicle stops and the vehicle does not skid.

2. The control apparatus for the vehicle according to claim 1, wherein the electronic control unit is configured to determine whether the vehicle skids based on a rotation angle of the three-phase AC motor.

3. The control apparatus for the vehicle according to claim 2, wherein the electronic control unit is configured to determine whether the vehicle skids based on a difference between a current rotation angle of the three-phase AC motor and a previous rotation angle of the three-phase AC motor.

4. The control apparatus for the vehicle according to claim 1, wherein the electronic control unit is configured to determine whether the vehicle skids based on the rotation speed of the three-phase AC motor.

5. The control apparatus for the vehicle according to claim 4, wherein the electronic control unit is configured to determine whether the vehicle skids based on an average value of the rotation speed of the three-phase AC motor in a predetermined period.

6. A control method for a vehicle, the vehicle including a three-phase AC motor and a power converter, the three-phase AC motor being driven at a rotation speed synchronized with a rotation speed of a drive shaft of the vehicle, and the power converter including a first switching element and a second switching element, which are connected in series to each other, for each of three phases of the three-phase AC motor and being configured to convert electric power supplied to the three-phase AC motor from DC power to AC power, the control method comprising:

determining whether the rotation speed of the three-phase AC motor is equal to or less than a predetermined threshold value and whether a stopping operation that stops the vehicle is performed;

determining that the vehicle stops when the rotation speed of the three-phase AC motor is equal to or less than the predetermined threshold value and the stopping operation is performed;

determining whether the vehicle skids; and

switching a state of the power converter to a state where all on one side of the first switching elements and the second switching elements are turned off and at least one on the other side of the first switching elements and the second switching elements is turned on when it is determined that the vehicle stops and it is determined that the vehicle does not skid.