Vehicle Dynamics Control Device

Abstract

A vehicle dynamics control device includes: a control unit that executes braking/driving torque control for controlling at least either a braking torque or a driving torque at each wheel based upon at least either external information pertaining to an environment of a vehicle or vehicle information that includes operation input information indicating an operation input by a driver and a vehicle dynamics information. And the operation input information includes a lateral motion operation index pertaining to a lateral motion operation executed to generate a lateral motion in the vehicle; the vehicle dynamics information includes a longitudinal acceleration generated in the vehicle and a lateral motion index indicating a lateral motion occurring in the vehicle; and the control unit determines a handling assurance acceleration limit with a maximum longitudinal acceleration value that assumes a substantially linear proportional relationship with the lateral motion operation index and the lateral motion index over a range in which the lateral motion operation index assumes a value equal to or less than a predetermined value or the lateral motion index assumes a value equal to or less than a predetermined value, and executes the braking/driving torque control by setting the handling assurance acceleration limit as an upper limit to a longitudinal acceleration to be generated in the vehicle under the braking/driving torque control.

1 . A vehicle dynamics control device, comprising:
 a control unit that executes braking/driving torque control for controlling at least either a braking torque or a driving torque at each wheel based upon at least either external information pertaining to an environment of a vehicle or vehicle information that includes operation input information indicating an operation input by a driver and a vehicle dynamics information, wherein:   the operation input information includes a lateral motion operation index pertaining to a lateral motion operation executed to generate a lateral motion in the vehicle;   the vehicle dynamics information includes a longitudinal acceleration generated in the vehicle and a lateral motion index indicating a lateral motion occurring in the vehicle; and   the control unit determines a handling assurance acceleration limit with a maximum longitudinal acceleration value that assumes a substantially linear proportional relationship with the lateral motion operation index and the lateral motion index over a range in which the lateral motion operation index assumes a value equal to or less than a predetermined value or the lateral motion index assumes a value equal to or less than a predetermined value, and executes the braking/driving torque control by setting the handling assurance acceleration limit as an upper limit to a longitudinal acceleration to be generated in the vehicle under the braking/driving torque control.   
     
     
         2 . A vehicle dynamics control device according to  claim 1 , wherein:
 the lateral motion operation index is made up with part of or the whole of an absolute value representing a steering angle or an absolute value representing a side slip angle; and   the lateral motion index is made up with at least part of or the whole of an absolute value representing a lateral acceleration generated in the vehicle or an absolute value representing a yaw rate generated in the vehicle.   
     
     
         3 . A vehicle dynamics control device according to  claim 1 , wherein:
 the predetermined value referenced for the lateral motion operation index and the predetermined value referenced for the lateral motion index are each at least one of a preselected value, a value entered by the driver and a value set based upon at least either the external information or the operation input information.   
     
     
         4 . A vehicle dynamics control device according to  claim 1 , wherein:
 the maximum longitudinal acceleration value is set based upon a value selected based upon an extent of nonlinearity of a braking/driving force generated at each wheel relative to a braking/driving torque control input, an acceleration limit indicating a limit to acceleration that can be generated at a road surface upon which the subject vehicle is traveling, determined through estimation or detection, and the handling assurance acceleration limit.   
     
     
         5 . A vehicle dynamics control device according to  claim 1 , further comprising:
 a first braking torque input unit via which the driver enters a braking torque with an upper limit to a longitudinal force to be generated set with a friction force limit or an upper limit to an acceleration to be generated set with a acceleration limit; and   a second braking torque input unit via which the driver enters a braking torque with an upper limit to a braking force to be generated set with a handling assurance limit or an upper limit to the acceleration to be generated set with the handling assurance acceleration limit.   
     
     
         6 . A vehicle dynamics control device according to  claim 1 , further comprising:
 a first driving torque input unit via which the driver enters a driving torque with an upper limit to a longitudinal force to be generated set with a friction force limit or an upper limit to an acceleration to be generated set with a acceleration limit; and   a second driving torque input unit via which the driver enters a driving torque with an upper limit to a braking force to be generated set with the handling assurance limit or an upper limit to the acceleration to be generated set as the handling assurance acceleration limit.   
     
     
         7 . A vehicle dynamics control device, comprising:
 a control unit that executes braking/driving torque control for controlling at least either a braking torque or a driving torque for each wheel based upon at least either external information pertaining to the environment of the vehicle or vehicle information that includes operation input information indicating an operation input by a driver and vehicle dynamics information, wherein:   the operation input information includes a lateral force operation index pertaining to a lateral force operation executed to generate a lateral force at the wheel;   the vehicle dynamics information includes a wheel lateral force index indicating a lateral force generated at the wheel; and   the control unit determines a handling assurance limit with a maximum longitudinal force value that assumes a substantially linear proportional relationship with the lateral force operation index and the wheel lateral force index over a range in which the lateral force operation index assumes a value equal to or less than a predetermined value or the wheel lateral force index assumes a value equal to or less than a predetermined value, and executes the braking/driving torque control by setting the handling assurance limit as an upper limit to a longitudinal force to be generated in the vehicle under the braking/driving torque control.   
     
     
         8 . A vehicle dynamics control device according to  claim 7 , wherein:
 the lateral force operation index is made up with part of or the whole of an absolute value representing a steering angle or an absolute value representing a side slip angle; and   the lateral force index is made up with part of or the whole of a lateral force generated at the wheel, an absolute value representing a lateral acceleration generated in the vehicle or an absolute value representing a yaw rate generated in the vehicle.   
     
     
         9 . A vehicle dynamics control device according to  claim 7 , wherein:
 the predetermined value referenced for the lateral force operation index and the predetermined value referenced for the lateral force index are each at least one of a preselected value, a value entered by the driver and a value set based upon at least either the external information or the operation input information.   
     
     
         10 . A vehicle dynamics control device according to  claim 7 , wherein:
 the maximum longitudinal acceleration value is set based upon a value selected based upon an extent of nonlinearity of a braking/driving force generated at each wheel relative to a braking/driving torque control input, a friction force limit with regard to a longitudinal force that can be generated at a road surface upon which the subject vehicle is traveling, determined through estimation or detection and the handling assurance limit.   
     
     
         11 . A vehicle dynamics control device according to  claim 7 , further comprising:
 a first braking torque input unit via which the driver enters a braking torque with an upper limit to the longitudinal force to be generated set with a friction force limit or an upper limit to an acceleration to be generated set with a acceleration limit; and   a second braking torque input unit via which the driver enters a braking torque with an upper limit to a braking force to be generated set with the handling assurance limit or an upper limit to the acceleration to be generated set with a handling assurance acceleration limit.   
     
     
         12 . A vehicle dynamics control device according to  claim 7 , further comprising:
 a first driving torque input unit via which the driver enters a driving torque with an upper limit to a longitudinal force to be generated set with a friction force limit or an upper limit to the acceleration to be generated set with a acceleration limit; and   a second driving torque input unit via which the driver enters a driving torque with an upper limit to a braking force to be generated set with the handling assurance limit or an upper limit to the acceleration to be generated set with a handling assurance acceleration limit.