Regenerative Braking Torque Control for Stop-Aware Energy Recovery
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Solution Overview
Problem
Existing regenerative braking systems in vehicles fail to efficiently quantify and correct for inefficiencies caused by driver behavior and road conditions, leading to significant energy loss.
Innovation Solution
A system utilizing sensors and a controller to determine optimal braking torque based on vehicle dynamics, speed, and proximity to a stop location, incorporating a continuously variable transmission and fuzzy logic controller to adjust gear ratios for maximum energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional friction braking is used, then stopping reliability is ensured, but energy is lost as heat
Solution Approach 1:
The patent converts the harmful effect of kinetic energy that would normally be dissipated as heat during braking into a beneficial resource by using the electric machine to generate electricity from the vehicle's motion, transforming energy loss into usable electrical energy for battery charging
Solution Approach 2:
The patent replaces the traditional mechanical friction braking system with an electrically-controlled regenerative braking system using an electric machine that can operate in both motor and generator modes, eliminating the need for friction-based energy dissipation
2Loss of energy
If regenerative braking is implemented, then energy recovery is improved, but driver behavior causes inefficiency
Solution Approach 1:
The system enables the vehicle to automatically manage its own braking energy recovery without requiring driver intervention or awareness, with the controller autonomously determining optimal braking torque based on stored map data and current vehicle conditions
Solution Approach 2:
The system uses feedback from sensors monitoring vehicle speed, acceleration, and braking conditions to continuously adjust the regenerative braking torque, with the controller referencing stored map data to optimize energy recovery based on real-time vehicle state
3Loss of energy
If automated control is added, then energy efficiency is maximized, but system complexity increases
Solution Approach 1:
The system pre-stores optimal braking torque map data that has been calculated in advance based on vehicle characteristics and driving conditions, allowing the controller to quickly retrieve and apply optimal values without complex real-time calculations, thus maximizing energy efficiency while minimizing processing complexity
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
Significantly increases energy recovery during braking by up to 61% compared to human-driven systems, particularly in urban environments, enhancing vehicle range and reducing energy dissipation.
Implementation Method 1
The electric machine (e.g., electric motor/generator) is coupled (e.g., at least indirectly) to a wheel of the vehicle
Implementation Method 2
The torque sensor is configured to provide torque information indicative of a torque between the electric machine and the wheel
Implementation Method 3
The speed sensor is configured to provide speed information indicative of a speed of the electric machine or a speed of the vehicle
Data Source
AI summary
A regenerative braking system includes an electric machine coupled to a wheel of the vehicle. The system includes a distance sensor configured to provide distance information (e.g., a stop location), a torque sensor configured to provide torque information between the electric machine and the wheel, and a speed sensor configured to provide speed information indicative of a speed of the electric machine or a speed of the vehicle. A controller includes a processor and a memory storing instructions executable by the processor to: send a query to a stored map that includes energy efficiency information corresponding to the vehicle, the query including the distance and speed information; output a desired braking torque from the map based on the query and a maximum possible energy efficiency value of the stored map; and control operation of the electric machine based on the torque information and the desired braking torque.