Vehicle Control System Pitching Motion Reduction
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Solution Overview
Problem
Existing vehicle control systems that minimize bouncing and pitching motion using friction brakes often create an unnatural sensation for passengers due to strong deceleration, as they simultaneously control both motions which leads to increased manufacturing costs and high-frequency vibrational inputs.
Innovation Solution
The system prioritizes minimizing pitching motion over bouncing motion by applying braking torque to at least the front wheel and all four wheels, using a configuration that specializes in pitch control to reduce deceleration sensations, and employs a driving state estimator and frequency-sensitive control to optimize damping forces based on driving conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If braking torque is applied to all four wheels to minimize both bouncing and pitching motion, then vehicle body orientation control is improved, but deceleration sensation becomes too strong creating unnatural ride feeling
Solution Approach 1:
The patent segments the brake control into two independent control modes: pitch control that applies braking torque only to front wheels to minimize pitching motion, and bounce control that applies braking torque to all four wheels to minimize bouncing motion. This segmentation allows selective application of braking torque based on the specific vibration mode being controlled, thereby reducing unnecessary deceleration sensation while maintaining effective orientation control.
2Stability of the object's composition
If friction brakes are used to control vehicle body orientation, then pitching and bouncing motion is minimized, but manufacturing cost increases
Solution Approach 1:
The patent makes the existing friction brake system perform multiple functions by implementing two distinct control modes: pitch control mode that uses front wheel braking for pitch stabilization, and bounce control mode that uses all-wheel braking for bounce suppression. This multi-functionality allows the same brake hardware to address different vehicle body vibrations without requiring additional active control actuators, thereby controlling manufacturing costs while maintaining effective orientation control.
3Stability of the object's composition
If braking torque is applied to minimize bouncing motion, then vehicle body vibration is reduced, but high-frequency vibrations are generated creating unnatural sensation
Solution Approach 1:
The patent implements dynamic control mode selection that adapts the brake control strategy based on the specific vibration condition. The system switches between pitch control mode (front wheel braking) and bounce control mode (all-wheel braking) depending on whether pitching or bouncing motion is the dominant vibration mode. This dynamic adaptation allows effective vibration suppression while minimizing the generation of high-frequency vibrations that create unnatural ride sensation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach minimizes unnatural sensations for passengers by reducing deceleration and high-frequency vibrations, while maintaining effective vibration damping and reducing the burden on suspension systems, allowing for more comfortable and stable vehicle control.
Implementation Method 1
applying braking torque from a friction brake to at least a front wheel
Data Source
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AI summary
Provided are a state quantity detection means for detecting a state quantity indicating a vehicle body orientation, and a friction brake orientation control means for minimizing pitching motion in the vehicle body orientation by applying braking torque from friction brakes to at least front wheels and minimizing bouncing motion in the vehicle body orientation by applying braking torque from the friction brakes to all four wheels, the friction brake orientation control means prioritizing minimizing pitching motion over minimizing bouncing motion.