Brake Control Device Switching Logic for Driver Intention

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Solution Overview

Problem

Existing brake control systems face challenges in switching from antilock reduction control to antilock control according to a driver's intention, especially when unexpected events occur, such as engine stalls, leading to impaired convenience due to unnecessary operations required to return to antilock reduction control.

Innovation Solution

A brake control device and method that allows a forcible switchover from antilock reduction control to antilock control only when a driver intentionally stops the vehicle's drive source, using a brake ECU connected via a CAN network to detect driver operations and execute state transitions based on predetermined conditions to ensure the switchover aligns with the driver's intention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a restart of the engine alone is set as a trigger of switchover of control, then the switchover from antilock reduction control to antilock control can be executed automatically, but convenience is impaired by the burden of operation for returning control to antilock reduction control again when an unexpected event occurs

Engineering Contradiction:
Improveautomatic switchover executionVSAvoidoperation burden for returning control
Core Design Contradiction:
Extent of automationVSEase of operation

Solution Approach 1:

The patent applies dynamics by making the switchover trigger condition adaptive rather than static. Instead of simply triggering on any engine restart, the system dynamically evaluates whether the restart was intentional (driver operation) or unintentional (unexpected event) by checking if the vehicle was stopped and the brake pedal was depressed. This dynamic condition assessment allows the system to automatically switch control only when appropriate, avoiding unnecessary manual intervention while maintaining safety.

Inventive Principle:
Principle #15Dynamics

2Reliability

If forcible switchover is executed on any engine restart, then compliance with laws (e.g., ECE R78) is achieved, but convenience is impaired when unexpected events such as unintended engine stall occur

Engineering Contradiction:
Improvecompliance with regulationsVSAvoidconvenience during unexpected events
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies local quality by creating different switchover behaviors for different local conditions of engine restart. Rather than applying a uniform switchover rule to all engine restarts, the system checks specific local conditions (whether the vehicle was stopped, whether the brake pedal was depressed) to determine the nature of the restart. This allows compliant automatic switchover for intentional restarts while avoiding forced switchover for unintentional events, maintaining both regulatory compliance and operational convenience.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If the switchover condition is made strict to avoid unexpected switchover, then convenience is improved, but the ability to execute switchover according to driver intention is reduced

Engineering Contradiction:
ImproveconvenienceVSAvoidresponse to driver intention
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent applies feedback by using the vehicle's operational state (stopped condition) and driver input state (brake pedal depression) as feedback signals to determine whether an engine restart is intentional. This feedback mechanism allows the system to accurately distinguish between driver-intended restarts and unexpected events, enabling appropriate automatic switchover execution without overly strict or overly permissive conditions, thus balancing convenience with responsiveness to driver intention.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3932759B1Brake control device
Publication Date: 2023.04.19 YAMAHA MOTOR CO LTD
  • EP3932759B1 patent drawingFigure 1
  • EP3932759B1 patent drawingFigure 2~3
  • EP3932759B1 patent drawingFigure 4

AI summary

A brake control device includes: a detection unit configured to detect an ON operation for turning power of a vehicle on and an OFF operation for turning the power off, the ON operation and the OFF operation each being executed via a first operation input unit provided on the vehicle, and an actuation operation for actuating a drive source and a stop operation for stopping actuation of the drive source, the actuation operation and the stop operation each being executed via a second operation input unit provided on the vehicle separately from the first operation input unit; and a control unit configured to selectively execute, by controlling a braking force adjustment mechanism, either antilock control for suppressing lock of the wheel or antilock reduction control for reducing a suppression degree of lock of the wheel more than that in the antilock control. The control unit executes the antilock control by switching over from the antilock reduction control when the stop operation is detected during execution of the antilock reduction control, the drive source stops, and the vehicle stops.