Brake Control Unit Regenerative Target Inflation for Delay Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In regenerative braking systems, processing delays between the brake ECU and hybrid ECU can cause divergence between target and execution values, leading to friction energy conversion instead of regeneration, thereby increasing fuel consumption and affecting brake feel.
Innovation Solution
A brake control system that adjusts the regenerative brake unit's target value based on an inflated value to compensate for response delays, ensuring efficient use of regenerative braking by calculating a second regenerative target value larger than the first, and adjusts this value based on the gradient of the target braking force and vehicle speed to enhance brake feel and energy recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the regenerative brake unit is controlled based on the first regenerative target value calculated from the target braking force, then the braking force distribution is determined, but a response delay causes divergence between target and execution values leading to friction energy conversion instead of regeneration
Solution Approach 1:
The brake control unit calculates a second regenerative target value that is larger than the first regenerative target value in advance, before the response delay occurs. This preliminary inflation of the target value compensates for the anticipated delay in execution, ensuring that the regenerative brake unit receives sufficient target value even after the delay, thereby maintaining energy recovery efficiency without wasting braking force as friction energy.
2Loss of energy
If the second regenerative target value is inflated to compensate for response delay, then regenerative braking efficiency is improved, but excessive inflation may cause discomfort in brake feel
Solution Approach 1:
The brake control unit dynamically adjusts the inflation amount of the second regenerative target value based on the gradient of the target braking force. When the gradient is large (rapid braking), a larger inflation amount is applied to compensate for delay. When the gradient is small (gradual braking), a smaller inflation amount is applied to maintain comfortable brake feel. This dynamic adjustment optimizes both energy recovery efficiency and driver comfort across different braking scenarios.
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 improves fuel efficiency by maximizing regenerative braking, reduces discomfort in brake feel, and ensures reliable execution of regenerative braking forces, thereby enhancing the overall braking performance.
Implementation Method 1
a regenerative brake unit configured to generate a regenerative braking force
Implementation Method 2
a friction brake unit configured to generate a friction braking force
Data Source
AI summary
A brake control system includes: a friction brake unit configured to generate a friction braking force; a regenerative brake unit configured to generate a regenerative braking force; and a brake control unit configured to control the regenerative brake unit and the friction brake unit based on a regenerative target value and a friction target value based on a target braking force, which is a target of the braking force to be provided to a wheel. The brake control unit controls the regenerative brake unit based on a second regenerative target value larger than a first regenerative target value that has been defined based on the target braking force.