Steer-by-Wire Status Code Reduces Communication Load

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Solution Overview

Problem

The existing steer-by-wire steering systems face increased communication load when multiple controllers manage steering and operation counterforce controls independently, requiring transmission of various parameters, which can lead to system delays and inefficiencies.

Innovation Solution

A steer-by-wire steering system where the steering controller determines a status code based on the steering device's conditions and transmits it to the operating controller, allowing the operating controller to adjust the operation counterforce accordingly, reducing the communication load by using a single status code to execute counterforce changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If two individual controllers are used to independently execute steering control and operation counterforce control, then system versatility and control independence are improved, but communication load increases due to transmission of multiple parameters

Engineering Contradiction:
Improvecontrol independenceVSAvoidcommunication load
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The invention extracts only the essential status information needed for counterforce control from the full set of steering device parameters. Instead of transmitting all steering parameters (steering speed, supply current, temperature, voltage), the steering controller determines and transmits only a status code that represents the essential state, thereby reducing communication load while maintaining control independence

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention transforms multiple continuous parameters (steering speed, current, temperature, voltage) into a discrete status code parameter. This parameter transformation reduces the amount of data transmitted over the communication line while still conveying the necessary information for the operating controller to adjust operation counterforce appropriately

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

This approach reduces the communication load and improves system efficiency by allowing simultaneous control of operation counterforce based on the steering device's status, enhancing the overall utility of the steer-by-wire steering system.

Implementation Method 1

a counterforce applying mechanism configured to apply, to the steering operating member, an operation counterforce by a counterforce motor

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

a steering actuator configured to steer a wheel by a steering motor

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Data Source

PatentEP4001055B1Steer-by-wire steering system
Publication Date: 2024.05.15 JTEKT CORP
  • EP4001055B1 patent drawingFigure 1
  • EP4001055B1 patent drawingFigure 2A~2C
  • EP4001055B1 patent drawingFigure 3

AI summary

A steer-by-wire steering system for a vehicle, including: an operating device (12) including a steering operating member (20), a counterforce applying mechanism (28) configured to apply, to the steering operating member (20), an operation counterforce by a counterforce motor (26), and an operating controller (60) configured to control the operation counterforce; a steering device (14) including a steering actuator (42) configured to steer a wheel (10) by a steering motor (50) and a steering controller (62) configured to control an amount of steering of the wheel (10) by the steering actuator (42); and a communication line (66) communicably connecting the operating controller (60) and the steering controller (62), wherein the steering controller (62) is configured to: determine a status code based on a status of the steering device (14); and transmit the status code to the operating controller (66) via the communication line (66); and wherein the operating controller (60) is configured to change a magnitude of the operation counterforce in accordance with the status code received by the operating controller (60).