Neutral Regenerative Braking Torque Control for Downhill Energy Recapture

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Solution Overview

Problem

Current regenerative braking systems in electric and hybrid vehicles lack consistency in applying torque, leading to suboptimal energy recapture and unnecessary wear on service brakes, especially during downhill driving, where energy could be regained and brake wear minimized.

Innovation Solution

A motor controller system that determines and applies optimal regenerative braking torque based on predefined or dynamically selected neutral braking torque curves, allowing for automatic energy recapture without driver input and minimizing service brake use, particularly in neutral and downhill modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If regenerative braking torque is manually selected by the driver, then the system is simple to operate, but the energy recapture is suboptimal and service brake wear increases

Engineering Contradiction:

Improveenergy recaptureVSAvoiddriver input requirement

Core Design Contradiction:

Loss of energyVSEase of operation

Solution Approach 1:

The regenerative braking system automatically determines and applies optimal torque without requiring driver input. The motor controller monitors vehicle conditions and autonomously activates regenerative braking when appropriate, allowing the system to serve itself rather than requiring manual driver selection of torque levels.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system dynamically adjusts regenerative braking torque based on real-time vehicle parameters such as speed, acceleration, and battery state of charge. By changing torque parameters automatically based on monitored conditions, the system optimizes energy recapture without requiring driver intervention.

Inventive Principle:

Principle #35Parameter changes

2Loss of energy

If service brakes are used to slow the vehicle downhill, then the vehicle can be controlled, but brake wear increases and energy recapture is lost

Engineering Contradiction:

Improveenergy recaptureVSAvoidvehicle control

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The system converts the gravitational force that causes vehicles to accelerate downhill into a beneficial regenerative braking force. By detecting downhill conditions through acceleration sensors and automatically applying regenerative torque, the system turns what would be energy waste and brake wear into energy recapture opportunities.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The motor controller continuously monitors vehicle acceleration, speed, and other parameters to detect downhill conditions. Based on this feedback, the system automatically adjusts regenerative braking torque to maintain vehicle control while maximizing energy recapture, replacing manual brake application.

Inventive Principle:

Principle #23Feedback

3Loss of energy

If regenerative braking torque is increased to maximize energy recapture, then energy efficiency improves, but vehicle stability may be compromised

Engineering Contradiction:

Improveenergy recaptureVSAvoidvehicle stability

Core Design Contradiction:

Loss of energyVSStability of the object's composition

Solution Approach 1:

The system dynamically adjusts regenerative braking torque based on real-time vehicle conditions rather than applying fixed torque levels. The motor controller continuously monitors acceleration, speed, and battery state of charge, adjusting torque dynamically to maintain stability while optimizing energy recapture under varying conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes torque parameters based on monitored vehicle state parameters. When stability is compromised or battery charge is sufficient, the system reduces regenerative torque; when conditions are favorable, it increases torque to maximize recapture, creating an adaptive torque control strategy.

Inventive Principle:

Principle #35Parameter changes

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

Enhances energy efficiency by maximizing energy recapture during regenerative braking, reducing service brake wear, and maintaining vehicle stability without driver intervention, especially on downhill slopes.

Implementation Method 1

a motor that is configured to act as a generator that converts mechanical energy generated from the braking process to electrical energy

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS11833928B2Regenerative braking for electric and hybrid vehicles

Publication Date: 2023.12.05 TOMCAR HLDG CO LLC

AI summary

A device comprises motor controller coupled to a drive motor and a battery pack of a vehicle. The motor controller comprises a processor that is configured to: determine that the vehicle is engaged in a neutral braking mode, and after determining that the vehicle is engaged in the neutral braking mode: select a neutral braking torque curve, determine a rotational velocity of the drive motor, based on the determined rotational velocity of the drive motor, determine an amount of regenerative braking torque to apply to the drive motor based on the selected neutral braking torque curve, apply the determined amount of regenerative braking torque to the drive motor, wherein applying the determined amount of regenerative braking torque to the drive motor results in a regenerative current generated by the drive motor, and supply the regenerative current to the battery pack to at least partially recharge the battery pack.