Hybrid Brake Control Predicting Regenerative Force
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Solution Overview
Problem
In hybrid vehicle brake systems, the combination of hydraulic and regenerative brake forces often results in excessive brake force application due to communication delays between control devices, leading to inefficient regeneration and poor brake operation feeling.
Innovation Solution
A brake control system that includes a differential amount calculating means, a regenerative range judging means, and hydraulic pressure restricting or increasing means to adjust hydraulic brake force based on the difference between requested and executed regenerative brake forces, ensuring the hydraulic brake force is synchronized with the regenerative brake force within its operational range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If constant time interval communication is used between control devices, then device complexity is reduced, but communication delay increases causing excessive brake force application
Solution Approach 1:
The control device predicts the regenerative brake force value at the current time point based on past values using time series analysis, performing the prediction action in advance before the actual communication occurs. This eliminates the need to wait for real-time communication data while maintaining accurate brake force coordination.
Solution Approach 2:
A prediction algorithm acts as an intermediary between the constant time interval communication and the real-time brake force control. The algorithm processes historical data to generate predicted values that bridge the time gap, allowing the hydraulic brake control to respond as if it had real-time information without requiring complex real-time communication infrastructure.
2Measurement precision
If hydraulic brake force is applied to compensate for communication delay, then brake force accuracy is improved, but regeneration efficiency deteriorates due to overlapping brake forces
Solution Approach 1:
The control device uses feedback from the predicted regenerative brake force values to dynamically adjust the hydraulic brake force. By continuously monitoring the difference between target brake force and predicted regenerative brake force, the system applies only the necessary hydraulic compensation, preventing overlapping brake forces while maintaining accurate total brake force control.
Solution Approach 2:
The hydraulic brake force is made dynamic and adaptive rather than static. The control device continuously calculates the required hydraulic brake force based on real-time prediction results, allowing the system to optimize the balance between hydraulic and regenerative brake forces according to actual operating conditions, thereby maximizing regeneration efficiency while ensuring brake force accuracy.
3Ease of operation
If regenerative brake force prediction is implemented, then brake operation feeling is improved, but device complexity increases due to additional calculation means
Solution Approach 1:
The patent replaces complex real-time communication hardware and mechanical feedback systems with a computational prediction model. By using time series analysis and mathematical algorithms, the system achieves real-time performance through software-based prediction rather than hardware-based real-time data transmission, reducing overall system complexity while improving brake operation feeling.
Data Source
AI summary
Vehicle brake system comprises a hydraulic brake device, a regenerative brake device to drive wheels driven by a generator-motor and a brake control device for cooperatively controlling the hydraulic brake force and the regenerative brake force in response to an operation amount of a brake operation member. This vehicle brake system further includes a differential amount calculating portion calculating a differential amount by subtracting a regeneration execution brake force obtained by execution of the generator-motor from a regeneration request brake force, a regenerative range judging portion for judging whether the regeneration request brake force is within a range of a re-generable brake force which is executable by the generator-motor and a hydraulic pressure restricting portion for restricting increase of the hydraulic brake force when the differential amount is a positive value and the regeneration request brake force is within the range of the re-generable brake force.