Vehicle Control System Braking Force Allocation for Roll and Dive Reduction
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Solution Overview
Problem
During vehicle turns, the application of deceleration braking force can cause dive behavior in the turning outer front road wheel, leading to occupant instability and difficulty in maintaining a seated posture, which affects ride quality and vehicle control.
Innovation Solution
A vehicle control system that adjusts braking forces by applying a greater deceleration braking force to the turning outer front road wheel compared to the turning inner front and outer rear road wheels, and equal to or greater than the deceleration braking force applied to the turning inner rear road wheel, to reduce roll and dive behaviors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If deceleration braking force is applied to each road wheel during vehicle turn, then vehicle deceleration is achieved, but dive behavior occurs in the turning outer front road wheel causing occupant instability
Solution Approach 1:
The patent applies different braking force allocation strategies to different road wheels based on their specific positions and functions. The turning outer front road wheel receives reduced braking force compared to other wheels to prevent dive behavior, while maintaining overall vehicle deceleration. This localized differentiation of braking force allocation resolves the contradiction between achieving deceleration and maintaining occupant stability.
Solution Approach 2:
The patent implements asymmetric braking force distribution among the four road wheels during turning deceleration. Specifically, the turning outer front road wheel is allocated less braking force than the turning inner front road wheel and turning rear wheels, creating an asymmetric pattern that counteracts the dive behavior tendency. This asymmetric allocation maintains vehicle deceleration while preventing occupant instability.
2Speed
If deceleration braking force is applied to each road wheel, then vehicle deceleration is achieved, but roll behavior and dive behavior increase affecting ride quality
Solution Approach 1:
The patent implements localized braking force reduction at the turning outer front road wheel to specifically counteract dive behavior, while maintaining appropriate braking forces at other wheels for overall deceleration. This targeted approach reduces harmful dive and roll behaviors without sacrificing deceleration performance.
Solution Approach 2:
The control system proactively adjusts braking force allocation before dive behavior becomes severe by reducing braking force at the turning outer front road wheel in anticipation of the dive tendency during turning deceleration. This preliminary counter-action prevents excessive roll and dive behaviors while maintaining ride quality.
Data Source
AI summary
In one mode, with a vehicle control apparatus, a vehicle control method, and a vehicle control system according to the present invention, during roll control based on roll-control driving force and roll-control braking force applied to road wheels of a vehicle, deceleration braking force is allocated such that first deceleration braking force applied to a turning outer front road wheel becomes greater than second deceleration braking force applied to a turning inner front road wheel and third deceleration braking force applied to a turning outer rear road wheel and becomes equal to or greater than fourth deceleration braking force applied to a turning inner rear road wheel. In this way, the roll behavior of the vehicle can be reduced, and the dive behavior toward the turning outer front road wheel can be reduced.