Brake Control Section Maintains Regenerative Braking During ABS Abnormality

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Solution Overview

Problem

In hybrid vehicle brake systems, abnormal ABS diagnosis can lead to sudden changes in brake force, causing unusual braking sensations for the driver and reducing regenerative braking efficiency.

Innovation Solution

A vehicle brake force generation device that includes an electric motor, hydraulic brake pressure generation, slip information computation, behavior-stabilization assistance, and a diagnosis section to maintain regenerative braking control even when the ABS or information communication is abnormal, ensuring a stable braking feeling and efficient energy recovery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If regenerative braking control is immediately prohibited when ABS diagnosis is abnormal, then wheel locking is avoided, but driver braking sensation becomes strange and regenerative braking efficiency decreases

Engineering Contradiction:
Improvewheel locking preventionVSAvoiddriver braking sensation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent dynamically adjusts the regenerative braking control strategy based on the type of ABS abnormality detected. Instead of uniformly prohibiting regenerative braking for all ABS failures, the system distinguishes between different failure modes and applies appropriate control strategies, thereby maintaining smooth braking sensation while preventing wheel locking where necessary.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the control parameter (regenerative braking enablement) based on the diagnosis result type. When the ABS abnormality is of a type that does not cause wheel locking, the system maintains regenerative braking control; when it is of a type that could cause wheel locking, the system prohibits regenerative braking. This parameter change resolves the contradiction between safety and driving comfort.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If regenerative braking control is immediately prohibited when ABS diagnosis is abnormal, then wheel locking is avoided, but the amount of electricity obtained by regenerative braking decreases

Engineering Contradiction:
Improvewheel locking preventionVSAvoidregenerative braking energy recovery
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent changes the control parameter (regenerative braking enablement) based on the diagnosis result type. When the ABS abnormality is of a type that does not cause wheel locking, the system maintains regenerative braking control to maximize energy recovery; when it is of a type that could cause wheel locking, the system prohibits regenerative braking. This parameter change resolves the contradiction between safety and energy recovery.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent converts the potentially harmful situation (ABS abnormality) into a beneficial outcome by using the diagnosis information to make intelligent control decisions. Instead of simply disabling regenerative braking for all abnormalities, the system uses the abnormality type to determine the appropriate control strategy, thereby preventing wheel locking while maximizing energy recovery when safe to do so.

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

3Reliability

If ABS control is performed with wheel driving electric motor in power running state, then wheel locking is prevented, but regenerative braking efficiency is reduced

Engineering Contradiction:
Improvewheel locking preventionVSAvoidregenerative braking energy recovery
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent changes the operating state parameter of the wheel driving electric motor based on the ABS control status and abnormality type. When ABS control is performed and the abnormality type requires it, the motor is controlled in power running state to prevent wheel locking; when ABS control is not required or the abnormality type allows it, the motor operates in regenerative state for energy recovery. This dynamic parameter change resolves the contradiction between wheel locking prevention and energy recovery.

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

The device provides a satisfactory braking experience and enhances regenerative braking efficiency by maintaining regenerative braking control during ABS or communication abnormalities, preventing sudden brake force changes and optimizing energy recovery.

Implementation Method 1

A wheel driving electric motor is used as an electric power generator in the control of the regenerative braking caused by a wheel driving electric motor, wherein a brake force is generated by a regenerative torque generated by the wheel driving electric motor.

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the operation amount of a brake pedal by a driver is converted into an electrical signal to be provided to an electric motor for driving a piston of a slave cylinder... Then, a hydraulic brake pressure is generated by compressive driving of the piston by the electric motor

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 3

Thus generated hydraulic brake pressure operates wheel cylinders to generate brake forces caused by friction.

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2876007B1Vehicle brake force generation device
Publication Date: 2017.12.20 HONDA MOTOR CO LTD
  • EP2876007B1 patent drawingFigure 1
  • EP2876007B1 patent drawingFigure 2A
  • EP2876007B1 patent drawingFigure 2B

AI summary

A vehicle brake force generation device (11) is provided with an electric motor (13) for applying drive force and regenerative brake force to the wheels (17) of an electric vehicle (V), a brake hydraulic pressure generation device (26) for generating the brake hydraulic pressure to be applied to the calipers (27) of the electric vehicle (V), a slip information computation unit (63) for computing the slip information of the wheels (17), a VSA device (18) for controlling the friction braking of at least the brake hydraulic pressure generation device (26) such that the slipping of the wheels (17) is inhibited, a first diagnosis unit (67) for diagnosing the VSA device (18), and a brake control unit (65) for controlling the cooperative braking which includes controlling the regenerative braking of the electric motor (13) and/or controlling the friction braking of the brake hydraulic pressure generation device (26). The brake control unit (65) continues to control the regenerative braking of the electric motor (13) when a behavior stabilization assistance device (18) goes into an abnormal state while the regenerative braking of the electric motor (13) is being controlled.