EV Regenerative Braking Torque Control to Prevent Wheel Lock
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electric vehicles experience poor driver experience during braking on rough roads due to wheel locking and triggering of chassis functions, such as ABS, when energy recovery torque is not managed effectively.
Innovation Solution
A method to determine a threshold for braking energy recovery torque based on driving mode and road conditions, limiting the torque to prevent wheel locking by adjusting the braking torque distribution between hydraulic and energy recovery systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If energy recovery torque is increased during braking, then energy recovery efficiency is improved, but wheel locking probability increases causing poor driver experience
Solution Approach 1:
The patent dynamically adjusts the braking energy recovery torque parameter based on vehicle speed, deceleration rate, and road conditions. By changing the torque parameter adaptively rather than using a fixed high value, the system maximizes energy recovery while preventing wheel locking and maintaining braking stability.
Solution Approach 2:
The patent implements a dynamic control strategy where the braking energy recovery torque is continuously adjusted based on real-time vehicle state parameters (speed, deceleration) and environmental conditions (road adhesion). This dynamic approach allows the system to optimize energy recovery at each moment while avoiding wheel locking, resolving the contradiction between energy recovery efficiency and braking stability.
2Power
If braking energy recovery torque threshold is set high, then energy recovery capability is improved, but chassis function triggering probability increases
Solution Approach 1:
The patent applies preliminary anti-action by setting a threshold for braking energy recovery torque that prevents chassis functions from being triggered in the first place. By limiting the torque to stay below the threshold that would cause wheel locking or trigger ABS/ESP, the system proactively avoids the harmful effect while still maintaining effective braking and energy recovery capability.
3Speed
If motor braking response speed is increased, then braking responsiveness is improved, but wheel locking risk increases on rough roads
Solution Approach 1:
The patent applies partial action by using only the necessary portion of available motor braking power rather than maximum power. By controlling the braking energy recovery torque to be less than or equal to the threshold and adjusting it based on road conditions, the system achieves sufficient braking responsiveness without exceeding the point where wheel locking occurs, thus resolving the contradiction between response speed and wheel locking risk.
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
Reduces the probability of triggering chassis functions, improving driver experience by maintaining consistent braking and reducing the risk of accidents.
Implementation Method 1
When the electric vehicle brakes or coasts, mechanical energy generated by the electric vehicle during movement may be recovered by using the function and converted into electric energy for storage. A reverse torque may be generated during energy recovery of a motor for braking of the electric vehicle.
Implementation Method 2
A braking system of the electric vehicle can achieve braking effect based on an energy recovery torque of the motor and a hydraulic braking torque.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A braking method is provided. The braking method is applied to a vehicle, and includes: determining a threshold of a braking energy recovery torque based on a driving mode of the vehicle; obtaining a braking request; determining a braking energy recovery torque value based on the braking request, where the braking energy recovery torque value is less than or equal to the threshold; and outputting a braking torque, where the braking torque is determined based on a total energy recovery torque value, and the total energy recovery torque value is a sum of the braking energy recovery torque value and a coasting energy recovery torque value. In the braking method, because the braking torque output by a motor during braking may be decreased based on the threshold of the braking energy recovery torque, a probability of locking of a wheel can be reduced. This reduces a probability of triggering a chassis function and improves experience of a driver. A braking apparatus related to the braking method, a vehicle, a computer-readable storage medium, and a computer program product are further included.