Regenerative Braking Compensation for CAN Communication Failures
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for compensating regenerative braking in electric vehicles fail to accurately adjust the regenerative and hydraulic braking forces when CAN communication errors occur, leading to reduced energy recovery and inconsistent braking feel due to limitations in matching torque increments or decrements between the two systems.
Innovation Solution
A method that determines if regenerative braking is activated, remembers the normal regenerative braking control amount, calculates the difference between normal and failure-state braking amounts, and compensates the braking force by adjusting the regenerative braking control in the EBS and HCU, ensuring battery charging strategy and improved fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If regenerative braking control is reduced when CAN communication fails, then hydraulic braking force can be increased to maintain braking performance, but energy recovery efficiency deteriorates
Solution Approach 1:
The system stores the regenerative braking control amount calculated just before CAN communication failure in advance. When failure occurs, this pre-stored value is retrieved and used to compensate for the regenerative braking amount, avoiding the need to recalculate from scratch and maintaining energy recovery efficiency while ensuring braking performance
Solution Approach 2:
The system calculates the difference between the stored normal-state regenerative braking control amount and the braking amount during failure state. This difference value is fed back to compensate the regenerative braking amount during failure, creating a closed-loop control that maintains both braking performance and energy recovery efficiency
2Device complexity
If regenerative braking amount is not compensated during CAN communication failure, then system complexity is reduced, but braking feel consistency deteriorates
Solution Approach 1:
The system creates a copy of the regenerative braking control amount calculated in normal state and stores it in the HCU. During CAN communication failure, this copied value is retrieved and used to compensate the regenerative braking amount, providing a simple yet effective solution that maintains braking feel consistency without adding complex control logic
Solution Approach 2:
The regenerative braking control amount is stored in advance before failure occurs. This preliminary storage action allows the system to quickly retrieve and use the stored value during failure without complex real-time calculations, maintaining both system simplicity and braking consistency
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 method effectively compensates for regenerative braking failures by adjusting the braking force based on vehicle state, ensuring consistent braking feel and improved energy recovery and fuel efficiency.
Implementation Method 1
the driving motor plays a role of driving the vehicle and, at the same time, performs the regenerative braking in reducing the vehicle driving speed as well, thus collecting the kinetic energy and storing the same
Implementation Method 2
a hydraulic brake system that causes a braking force by the hydraulic pressure
Implementation Method 3
the hydraulic braking force that generates thermal energy by the frictional force of a disc and a pad
Data Source
AI summary
A method for compensating a regenerative braking amount when regenerative braking of a vehicle fails due to an error in controller area network (CAN) communications between an electronic brake system (EBS) and a hybrid control unit (HCU). The method includes steps of determining whether or not the regenerative braking is activated, remembering a regenerative braking control amount in the HCU and the EBS, learning and remembering a difference between the regenerative braking control amount in a normal state calculated just before the failure and the braking amount for the failure check in the HCU and the EBS, compensating the braking amount for the failure check with the difference value between the normal regenerative braking control amount and the braking amount for the failure check, and performing a regenerative braking control in the HCU and the EBS respectively.