Steering Wheel Neutral Position Recovery After Battery Replacement

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Solution Overview

Problem

In steer-by-wire steering devices, the neutral position of the steering wheel can be lost when the battery is removed, requiring re-establishment of steering angle midpoint information, which is inefficient and can cause discomfort to the driver.

Innovation Solution

A steering device with a stopper mechanism and a controller that executes processes to compute the neutral position of the steering wheel by controlling a motor to operate to specific operation ends and reverse, using the rotational angle of the motor to determine the neutral position upon power restoration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the battery is removed for replacement, then the vehicle power source is lost, but the steering angle midpoint information stored in the controller is erased, requiring time-consuming re-storing of neutral position data

Engineering Contradiction:

Improveease of battery replacementVSAvoidtime to re-store steering angle midpoint information

Core Design Contradiction:

Ease of manufactureVSLoss of time

Solution Approach 1:

The system automatically performs preliminary action by detecting the neutral position of the steering wheel and storing the steering angle midpoint information in the controller automatically when power is restored after battery replacement, eliminating the need for manual re-storing operations and reducing time loss

Inventive Principle:

Principle #10Preliminary action

2Reliability

If the neutral position of the steering wheel is lost after battery replacement, then steering angle midpoint information must be re-stored, but this requires full system operation and calibration procedures

Engineering Contradiction:

Improveaccuracy of neutral positionVSAvoidcomplexity of re-calibration procedure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system performs self-service by automatically detecting the neutral position of the steering wheel through the stopper mechanism and motor rotational angle measurements, and autonomously storing the steering angle midpoint information in the controller without requiring manual calibration operations or full system procedures

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system replaces complex manual mechanical calibration procedures with an automated detection mechanism that uses the motor's rotational angle sensor and the stopper mechanism's physical limits to computationally determine and store the neutral position information

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If the steering wheel is operated to determine neutral position, then the neutral position can be re-established, but this requires operating the steering wheel through its full range of motion

Engineering Contradiction:

Improveprecision of neutral position detectionVSAvoidmotor torque required for steering wheel operation

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system applies partial action by operating the steering wheel only to the extent necessary to engage the stopper mechanism at the neutral position using the motor's limited rotational movement, rather than requiring the steering wheel to traverse its entire operational range, thereby reducing energy consumption while maintaining detection precision

Inventive Principle:

Principle #16Partial or excessive action

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 neutral position of the steering wheel is accurately re-established before vehicle operation, ensuring smooth steering without discomfort, and allows operation within the defined range without full system operation, reducing motor torque requirements.

Implementation Method 1

a motor configured to generate a steering reaction force that is torque in an opposite direction of a direction of steering applied to the steering shaft

Methodology Applied

Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Data Source

PatentUS12522285B2Steering device

Publication Date: 2026.01.13 JTEKT CORP

AI summary

A steering device includes a steering shaft, a motor, a stopper mechanism, and a controller. The controller is configured to execute a first process and a second process when a determined condition is established. The first process includes causing the steering wheel to operate to a first operation end through control of the motor and thereafter operate in reverse to a second operation end. The second process includes computing a neutral position of the steering wheel based on a rotational angle of the motor at a time when reverse operation of the steering wheel is started and at a time when the reverse operation of the steering wheel is ended.