Vehicle drive force distribution control system

摘要

A controller (8) controlling a drive force distributed to each wheel (1-4) of a vehicle sets dynamic drive force target values (Fxf**, Fx3**, Fx4**) to the wheels, and determines a variation amount target ratio related to variation amounts (ΔM, ΔFx, ΔFy) of a vehicle yaw moment (M), a vehicle front/aft force (Fx), and a vehicle lateral force (Fy) such that a vehicle behavior generated by the dynamic drive force target values does not vary. The controller (8) determines sets of the drive forces (Fxf(j, k), Fx3(j, k), Fx4(j, k)) realizing the variation amount target ratio, selects drive force command values from these sets such that each drive force command value is within a drive force limiting range, and controls a drive force regulating mechanism (20, 12, 13, 15,16) according to the selected drive force command values.

主权项

1. A driving/braking force control system for a vehicle having at least a pair of a right wheel and a left wheel which are independently controlled, comprising:
a driving/braking force regulating mechanism configured to apply a wheel driving/braking force to each of the wheels; and a programmable controller programmed to:
set dynamic wheel driving/braking force target values on the basis of a present operation state;calculate a vehicle front/aft force, a vehicle lateral force and a vehicle yaw moment as parameters representing vehicle behavior generated by the dynamic wheel driving/braking force target values;calculate a wheel driving/braking force limiting range for each of the dynamic wheel driving/braking force target values;determine, when one of the dynamic wheel driving/braking force target values is not within the wheel driving/braking force limiting range, a vehicle behavior variation amount target value that is based at least on variation amount target values of the vehicle front/aft force, the vehicle lateral force, and the vehicle yaw moment, the vehicle behavior variation amount target value being determined so as to maintain a ratio between the variation amount of the vehicle front/aft force and the variation amount of the vehicle lateral force maintained at cos β/sin β, where β is a vehicle skid angle; calculate a variation in a tire lateral force of each wheel accompanying a variation in the wheel driving/braking force of each wheel on the basis of a sensitivity of the tire lateral force of each wheel; calculate a plurality of sets of wheel driving/braking forces that achieve the vehicle behavior variation amount target value even when a variation in the tire lateral force of each wheel accompanying a variation in the wheel driving/braking force of each wheel occurs; select a set of wheel driving/braking forces from the plurality of sets of wheel driving/braking forces as wheel driving/braking force command values such that each of the wheel driving/braking forces in the selected set is within the driving/braking force limiting range; and control the driving/braking force regulating mechanism to apply wheel driving/braking forces to the right wheel and the left wheel according to the wheel driving/braking force command values.