Brake Force Switching for Pitch Control and Regenerative Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing braking control devices for vehicles face a trade-off between suppressing pitching motion and improving energy recovery efficiency during braking, as increasing frictional braking force for pitching suppression reduces regenerative braking force, and vice versa, leading to inadequate energy recovery or insufficient pitching motion control.
Innovation Solution
A braking control device that adjusts both frictional and regenerative braking forces by deriving a target vehicle braking force and controlling the regenerative braking device and frictional braking device to prioritize frictional braking force initially for pitching suppression, then switches to regenerative braking to enhance energy recovery efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If frictional braking force is increased to suppress pitching motion, then pitching suppression performance is improved, but regenerative braking force decreases and energy recovery efficiency deteriorates
Solution Approach 1:
The control device applies frictional braking force first during the initial phase of braking to ensure adequate pitching suppression. After a predetermined time elapses, it switches to regenerative braking force, which has sufficient deceleration performance but weaker pitching suppression. This preliminary action with frictional braking followed by regenerative braking resolves the contradiction by ensuring pitching control is established before transitioning to energy-efficient braking.
Solution Approach 2:
The braking control system dynamically switches between frictional and regenerative braking forces based on elapsed time since braking initiation. The control mode transitions from frictional-dominated (early phase) to regenerative-dominated (later phase), allowing the system to adapt to changing vehicle dynamics and energy recovery opportunities while maintaining adequate pitching suppression throughout the braking event.
2Loss of energy
If regenerative braking force is increased to improve energy recovery efficiency, then energy recovery efficiency is improved, but frictional braking force decreases and pitching suppression performance deteriorates
Solution Approach 1:
The system performs preliminary frictional braking to establish adequate pitching suppression before transitioning to regenerative braking. This ensures that the vehicle's pitching motion is controlled during the critical initial phase, and only after this suppression is established does the system switch to regenerative braking for energy recovery.
Solution Approach 2:
The control system dynamically adjusts the mix of frictional and regenerative braking forces over time. By switching from frictional to regenerative braking after a predetermined time, the system optimizes the balance between pitching suppression (dominant early) and energy recovery (dominant later), resolving the contradiction between these two performance aspects.
3Force
If frictional braking force is applied predominantly, then pitching motion suppression is adequate, but device complexity increases due to coordinated control of both braking systems
Solution Approach 1:
The control device uses a time-based dynamic switching strategy that automatically transitions from frictional to regenerative braking after a predetermined time interval. This dynamic approach simplifies control logic compared to continuous coordination, as the system follows a clear temporal sequence rather than requiring complex real-time optimization of both braking forces simultaneously.
Solution Approach 2:
The braking control follows a periodic pattern: frictional braking is applied during an initial period, then regenerative braking takes over for the subsequent period. This periodic action structure simplifies the control system by dividing the braking event into distinct phases with clear transition criteria, reducing the complexity of coordinated control while maintaining adequate pitching suppression.
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 effectively suppresses vehicle pitching motion while improving energy recovery efficiency by ensuring a sufficient regenerative braking force is applied after initial frictional braking force application, balancing both objectives.
Implementation Method 1
a regenerative braking device that adjusts a regenerative braking force applied to a wheel of the vehicle
Implementation Method 2
a frictional braking device that adjusts a frictional braking force applied to the wheel
Data Source
AI summary
The braking control device includes a control amount derivation unit that derives a target vehicle braking force representing a target value of a vehicle braking force applied, and a braking control unit that controls a regenerative braking device and a frictional braking device based on the target vehicle braking force. When the target vehicle braking force is increased, the braking control unit executes a braking force application process of increasing the frictional braking force applied to the wheel so that such frictional braking force becomes larger than the regenerative braking force applied to the wheel. When the target vehicle braking force is increased, the braking control unit executes a switching process of switching at least a part of the frictional braking force applied to the wheel to the regenerative braking force to increase the regenerative braking force applied to the wheel after execution of the braking force application process.