Regenerative Braking Control via Road Grade Detection
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Solution Overview
Problem
Existing electric vehicle systems are inadequate for controlling regenerative braking on inclined terrain, as the rate of regenerative braking is independent of operating conditions such as road grade, leading to inefficient energy use and potential safety issues.
Innovation Solution
Incorporating an inclinometer to determine the vehicle's angle of inclination and a control system that adjusts the rate of regenerative braking based on brake pedal position and inclination, optimizing regenerative braking rates to enhance energy efficiency and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the rate of regenerative braking is kept independent of operating conditions (road grade), then the system structure remains simple, but the braking performance becomes inadequate on inclined terrain
Solution Approach 1:
The regenerative braking rate is dynamically adjusted based on real-time road grade detection. The system transitions from a static, fixed braking rate to a dynamic rate that adapts to changing terrain conditions, ensuring optimal braking performance on both level and inclined surfaces without requiring complex manual intervention
Solution Approach 2:
The system implements feedback control by continuously monitoring road grade through the inclinometer and using this information to adjust the regenerative braking rate. This closed-loop control ensures that the braking force matches the actual terrain conditions, improving reliability while maintaining reasonable system complexity
2Use of energy by moving object
If the regenerative braking rate is increased for downhill braking, then energy recovery efficiency improves, but the risk of excessive braking force and vehicle instability increases
Solution Approach 1:
The system changes the braking rate parameter based on road grade angle. For downhill braking, the regenerative braking rate is increased to maximize energy recovery, while for uphill braking, it is reduced to prevent excessive braking force. This dynamic parameter adjustment optimizes energy efficiency while maintaining vehicle stability across different terrain conditions
Solution Approach 2:
The braking system transitions from a static, fixed-rate design to a dynamic system that continuously adapts the braking force based on real-time road grade detection. This dynamic adjustment prevents excessive braking force on inclines while maximizing energy recovery on descents, thereby maintaining vehicle stability
3Reliability
If the regenerative braking rate is decreased for uphill braking, then vehicle control and prevention of rollback improve, but energy recovery efficiency decreases
Solution Approach 1:
The system adjusts the regenerative braking rate parameter according to road grade: reducing it during uphill braking to maintain vehicle control and prevent rollback, while increasing it during downhill braking to maximize energy recovery. This conditional parameter adjustment ensures both safety and energy efficiency are optimized for the current terrain
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
The solution allows for smoother and more efficient braking on inclines by increasing regenerative braking rates when descending and decreasing them when ascending, reducing energy consumption and preventing rollback, thereby improving vehicle control and safety.
Implementation Method 1
an inclinometer configured to detect an inclination of the bus with respect to a horizontal plane
Implementation Method 2
During braking, the electric motor acts as a generator and energy flows from the wheels to the batteries via the motor
Data Source
AI summary
A method of operating an electric vehicle may include determining an angle of inclination of the electric vehicle, and selecting rates of regenerative braking corresponding to multiple brake pedal positions based on the determined angle of inclination.