Process for controlling wheel longitudinal force in vehicle

• US 5,551,771 A
• Filed: 01/11/1996
• Issued: 09/03/1996
• Est. Priority Date: 06/03/1993
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Inagaki, Hiromi, Akuzawa, Kenji
• Primary Examiner(s): YOUNG, LEE W
• Application Number:
  US08/583,958
• Time in Patent Office: 236 Days
• Field of Search: 303/9.67, 303/9.68, 303/9.69, 303/22.1, 303/24.1, 303/113.4, 303/113.5, 303/146, 303/147, 303/186, 303/187, 303/188, 303/189, 364/426.02, 364/426.03
• US Class Current: 303/186
• CPC Class Codes: B60T 8/1764 Regulation during travel on surface with different coefficients of friction, e.g. between left and right sides, mu-split or between front and rear
• CPC Class Codes: B60T 8/1766 Proportioning of brake forces according to vehicle axle loads, e.g. front to rear of vehicle
• CPC Class Codes: B60T 8/885 using electrical circuitry

Abstract

A total longitudinal force which is a sum total of the longitudinal forces applied to the plurality of wheels is detected or determined, and the longitudinal forces applied to the wheels are controlled on the basis of a front wheel-side target wheel longitudinal force and a rear wheel-side target wheel longitudinal force determined by distribution of the total longitudinal force at predetermined distribution proportions. When the slipping of a wheel is detected, the distribution proportions are changed, so that the target wheel longitudinal force is larger on one of the front and rear wheel sides in which more wheels are in non-slipping states.

Claims

1. A process for controlling a wheel longitudinal force in a vehicle in which longitudinal forces applied to a plurality of wheels (W_FR, W_FL, W_RR, W_RL) can be controlled at least on a front wheel side and on a rear wheel side, comprising the steps of:

detecting or determining a total longitudinal force which is a sum total of the longitudinal forces applied to the plurality of wheels (W_FR, W_FL, W_RR, W_RL) in accordance with a total braking fluid pressure;

controlling the longitudinal forces applied to the wheels on the basis of a front wheel-side target wheel longitudinal force and a rear wheel-side target wheel longitudinal force determined by distribution of said total longitudinal force at a predetermined distribution proportion; and

detecting the presents of a slipping state for each wheel,

changing said distribution proportion by increasing an amount of said distribution proportion to one of the front and rear wheel sides in which more wheels are not in the slipping state, such that the target wheel longitudinal force is larger for the one side,

wherein in changing said distribution proportion, the increased amount in said distribution proportion at a time when the front wheel-side target wheel longitudinal force is increased is determined larger than the increased amount in said distribution proportion at a time when the rear wheel-side target wheel longitudinal force is increased.

2. A process for controlling the wheel longitudinal force in a vehicle in which longitudinal forces applied to the plurality of wheels (W_FR, W_FL, W_RR, W_RL) are controllable independently, comprising the steps of:

detecting or determining a total longitudinal force which is a sum total of the longitudinal forces applied to the plurality of wheels (W_FR, W_FL, W_RR, R_RT) in accordance with a total braking fluid pressure;

controlling the longitudinal forces applied to the wheels on the basis of a front wheel-side target wheel longitudinal force and a rear wheel-side target wheel longitudinal force determined by distribution of said total longitudinal force at a predetermined distribution proportion; and

changing said distribution proportion such that the target wheel longitudinal force is larger on one of the front and rear wheel sides in which more wheels are in non-slipping states, when a slipping is detected in the wheels,

wherein said changing said distribution proportion step further comprises the steps of;

determining loads shared to the wheels (W_FR, W_FL, W_RR, W_RL) in a stopped state of the vehicle;

providing apparent direction and amount of displacement of a center of gravity position of the vehicle on the basis of a longitudinal acceleration and of a lateral acceleration of the vehicle;

determining an apparent center of gravity position of the vehicle in accordance with said direction and amount of displacement;

correcting the apparent center of gravity position of the vehicle when slipping is detected in the wheels, such that said apparent center of gravity position of the vehicle is displaced toward a side away from a wheel in a slipping state on a straight line connecting the slipping wheel and the apparent center of gravity position of the vehicle, as viewed in a plane;

correcting said determined shared loads on the basis of a corrected apparent center of gravity position of the vehicle; and

determining the distribution proportion of the wheel longitudinal force for every wheel (W_FR, W_FL, W_RR, W_RL) on the basis of corrected shared loads.