Regenerative Braking Control Device for Vehicle Energy Recovery

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Solution Overview

Problem

The challenge lies in determining an appropriate regenerative braking force for vehicles, which is affected by road surface friction, gradient, and vehicle weight, leading to inefficient fuel use and discomfort for drivers due to unpredictable deceleration and interference with brake operations.

Innovation Solution

A drive control device that uses an external recognition sensor to adjust regenerative braking force based on road conditions and driver input, maintaining or increasing energy conversion without hindering brake operations, by calculating target distances and speeds and integrating with friction braking systems to optimize fuel efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If regenerative braking force is increased to improve fuel efficiency, then energy recovery is improved, but vehicle deceleration becomes too strong causing driver discomfort and unnecessary stopping

Engineering Contradiction:
Improveenergy recoveryVSAvoiddriver comfort
Core Design Contradiction:
Loss of energyVSEase of operation

Solution Approach 1:

The regenerative braking force is made dynamic by continuously updating it based on real-time external world information (road gradient, friction coefficient, vehicle weight) acquired by external recognition sensors. This allows the system to adapt the braking force to current conditions, preventing excessive deceleration while maximizing energy recovery under optimal conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses feedback from external recognition sensors to continuously monitor road conditions, vehicle state, and obstacle information. This feedback loop enables the control unit to adjust regenerative braking force in real-time, ensuring it remains appropriate for current conditions and does not cause driver discomfort or unnecessary stopping.

Inventive Principle:
Principle #23Feedback

2Device complexity

If regenerative braking force is determined based on conditions immediately before accelerator release, then control simplicity is maintained, but accuracy of braking force determination deteriorates due to changing road conditions and vehicle state

Engineering Contradiction:
Improvecontrol simplicityVSAvoidbraking force determination accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system performs preliminary actions by continuously acquiring and processing external world information (road gradient, friction coefficient, vehicle weight) before regenerative braking is needed. This allows the control unit to have accurate, up-to-date data ready when braking force determination is required, improving accuracy without adding complexity to the braking control logic itself.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements continuous feedback from external recognition sensors to update vehicle state information. This ensures that when regenerative braking force is calculated, the most current and accurate data about road conditions and vehicle parameters are available, improving determination accuracy while maintaining control simplicity through automated sensor-based updates.

Inventive Principle:
Principle #23Feedback

3Loss of energy

If regenerative braking force changes while driver operates brake pedal to improve fuel efficiency, then energy recovery is improved, but driver's brake operation becomes hindered

Engineering Contradiction:
Improveenergy recoveryVSAvoidbrake operation
Core Design Contradiction:
Loss of energyVSEase of operation

Solution Approach 1:

The system dynamically adjusts regenerative braking force based on detected brake pedal operation. When the brake pedal is detected as operated, the system maintains or increases regenerative braking force appropriately rather than changing it arbitrarily, ensuring smooth and predictable braking behavior that does not hinder driver operation while still maximizing energy recovery.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The brake detector provides feedback about driver brake pedal operation to the control unit. This feedback allows the system to distinguish between driver-initiated braking and accelerator-release braking, enabling it to maintain stable regenerative braking force during driver operation and only adjust force under system-controlled conditions, preventing interference with driver intent.

Inventive Principle:
Principle #23Feedback

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 solution allows for increased regenerative braking without excessive deceleration, enhancing fuel efficiency and reducing driver discomfort by aligning braking forces with intended brake operations, thus improving overall vehicle performance.

Implementation Method 1

a driving motor that can be caused to perform a regenerative operation in which kinetic energy is converted to electric energy

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3075594B1Drive control device for movable body
Publication Date: 2019.02.20 HITACHI AUTOMOTIVE SYST LTD
  • EP3075594B1 patent drawingFigure 1
  • EP3075594B1 patent drawingFigure 2
  • EP3075594B1 patent drawingFigure 3

AI summary

To provide a drive control device of a moving body capable of increasing a regeneration amount without hindering a driver's brake operation and causing too much deceleration. A drive control device of a moving body that updates a regenerative pattern of a driving motor of the moving body including a brake that generates a braking force by being linked to an operation amount of a brake pedal, the drive control device including an external world information acquisition unit that acquires external world information and a brake detector that detects ON/OFF of the brake, wherein when the brake detector detects ON, the regenerative pattern is changed based on the external world information acquired by the external world information acquisition unit such that a braking distance only decreases.