Regenerative Braking Torque Control to Prevent Wheel Locking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electric vehicles experience poor driving experience due to the triggering of chassis functions, such as ABS or DTC, when braking on rough roads, as the wheel locks momentarily due to the combination of hydraulic and energy recovery torques.
Innovation Solution
A braking method that determines a threshold for braking energy recovery torque based on the vehicle's driving mode and road conditions, limiting the torque to reduce the likelihood of wheel locking by adjusting the motor and hydraulic braking torques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If energy recovery torque is applied during braking, then energy recovery efficiency is improved, but wheel locking probability increases on rough roads
Solution Approach 1:
The patent dynamically adjusts the energy recovery torque threshold based on driving mode and real-time vehicle state. In different driving modes (e.g., single-pedal mode, energy recovery mode), the system sets different torque thresholds to balance energy recovery efficiency and braking stability, preventing wheel locking on rough roads while maximizing energy recovery when conditions permit
Solution Approach 2:
The system changes the parameter of energy recovery torque threshold according to driving mode and vehicle state. By modifying this key parameter dynamically, the system optimizes the balance between energy recovery performance and braking reliability, ensuring that the torque applied during energy recovery does not exceed safe limits that could cause wheel locking
2Productivity
If braking energy recovery torque is increased, then braking efficiency is improved, but driver experience deteriorates due to chassis function triggering
Solution Approach 1:
The system continuously monitors vehicle state parameters including wheel speed, deceleration rate, and road conditions, and uses this feedback to adjust the energy recovery torque in real-time. This closed-loop control ensures that braking efficiency is optimized while preventing chassis functions like ABS or DTC from being triggered, thereby maintaining smooth braking and good driver experience
Solution Approach 2:
The braking system dynamically transitions between different operating states (energy recovery mode, hybrid braking mode, pure hydraulic braking mode) based on real-time conditions. This dynamic adjustment allows the system to maintain high braking efficiency while avoiding the triggering of chassis safety functions that would degrade driver experience
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, enhancing driver experience by maintaining consistent deceleration and preventing wheel locking during braking on rough roads.
Implementation Method 1
mechanical energy generated by the electric vehicle during movement may be recovered by using the function and converted into electric energy
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
AI summary
A braking method for a vehicle is provided. The method includes: determining a threshold of a braking energy recovery torque based on a driving mode; 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. 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.