Vehicle behavior control device

• US 9,889,846 B2
• Filed: 11/02/2016
• Issued: 02/13/2018
• Est. Priority Date: 11/06/2015
• Status: Active Grant

• Current Assignee: Mazda Motor Corporation
• Original Assignee: Mazda Motor Corporation
• Inventors: Sunahara, Osamu, Umetsu, Daisuke
• Primary Examiner(s): Shafi, Muhammad
• Application Number:
  US15/341,710
• Publication Number:
  US 20170129480A1
• Time in Patent Office: 468 Days
• Field of Search: 701 41
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 2510/207 Oversteer or understeer
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/105 Longitudinal acceleration
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 2710/1055 Output torque change rate
• CPC Class Codes: B60W 30/045 Improving turning performance
• CPC Class Codes: B60W 30/18145 Cornering
• CPC Class Codes: B62D 6/003 in order to control vehicle yaw movement, i.e. around a vertical axis B62D6/007 takes precedence

Abstract

The vehicle behavior control device is designed to control a behavior of a vehicle having steerable front road wheels. The vehicle behavior control device comprises a PCM configured to perform control to reduce a torque for the vehicle according to a steering speed of the vehicle, and acquire an understeer-causing state of the vehicle which is a factor causing understeer, wherein the PCM is further configured to perform control to, after reducing the torque, increase the torque at a change rate decided based on the understeer-causing state of the vehicle acquired by the PCM.

Claims

1. A vehicle behavior control device for controlling a behavior of a vehicle having steerable front road wheels, comprising:

driving force control part configured to perform control to reduce a driving force for the vehicle according to a yaw rate-related quantity which is related to a yaw rate of the vehicle; and

understeer-causing factor acquisition part configured to acquire an understeer-causing state of the vehicle which is a factor causing understeer,

wherein;

the driving force control part is further configured to perform control to, after reducing the driving force, increase the driving force at a change rate decided based on the understeer-causing state of the vehicle acquired by the understeer-causing factor acquisition part;

the understeer-causing factor acquisition part is operable to acquire a gross weight of the vehicle, as the understeer-causing state of the vehicle; and

the driving force control part is operable to reduce a change rate during increasing of the driving force to a smaller value, as the gross weight of the vehicle acquired by the understeer-causing factor acquisition part becomes larger.

2. The vehicle behavior control device as recited in claim 1, wherein the driving force control part is operable, when a steering wheel angle of the vehicle is increasing and the yaw rate-related quantity is increasing, to reduce the driving force according to the yaw rate-related quantity being increasing, and, subsequently, when the steering wheel angle decreases or becomes constant, to increase the driving force.

3. A vehicle behavior control device for controlling a behavior of a vehicle having steerable front road wheels, comprising:

driving force control part configured to perform control to reduce a driving force for the vehicle according to a yaw rate-related quantity which is related to a yaw rate of the vehicle; and

understeer-causing factor acquisition part configured to acquire an understeer-causing state of the vehicle which is a factor causing understeer, wherein;

the driving force control part is further configured to perform control to, after reducing the driving force, increase the driving force at a change rate decided based on the understeer-causing state of the vehicle acquired by the understeer-causing factor acquisition part;

the understeer-causing factor acquisition part is operable to acquire an elapsed period of time after installation of tires in the vehicle, as the understeer-causing state of the vehicle; and

the driving force control part is operable to reduce a change rate during increasing of the driving force to a smaller value, as the elapsed period of time after installation of tires in the vehicle, acquired by the understeer-causing factor acquisition part becomes larger.

4. The vehicle behavior control device as recited in claim 3, wherein the driving force control part is operable, when a steering wheel angle of the vehicle is increasing and the yaw rate-related quantity is increasing, to reduce the driving force according to the yaw rate-related quantity being increasing, and, subsequently, when the steering wheel angle decreases or becomes constant, to increase the driving force.

5. A vehicle control device comprising a controller to which at least a steering wheel angle, an accelerator position and a vehicle speed are input, and which is configured to control a driving force output from a driving force generator based on the steering wheel angle, the accelerator position and the vehicle speed, wherein the controller is configured to:

reduce the driving force so as to generate an additional deceleration to be added to the vehicle according to steering speed, with reference to a map defining the additional deceleration to be set according to the steering speed, when the steering wheel angle is increasing and the steering speed is not decreasing;

reduce the driving force so as to generate the additional deceleration at the maximum steering speed when the steering wheel angle is increasing and the steering speed is decreasing;

increase the driving force so as to reduce the additional deceleration when the steering wheel angle is not increasing; and

reduce a reduction rate of the additional deceleration during the decreasing thereof to a smaller value, as a gross weight of the vehicle becomes larger.