Steering Wheel Lock Control for Turning With Steering Failure

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Solution Overview

Problem

When a vehicle is turning, self-aligning torque generated in the wheels can prevent it from turning in accordance with a requested steering input, especially when the steering device is anomalous.

Innovation Solution

A vehicle control device and method that includes a steering wheel lock mechanism to prevent steering wheel rotation and a remaining device, such as a steered angle adjustment device, to adjust the lateral movement of the vehicle, allowing the vehicle to turn even with an anomalous front-wheel steering device by switching the steering wheel lock mechanism to an activated state and utilizing the remaining device to adjust the steered angle ratio.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the vehicle turns by generating a difference in braking force or driving force between left and right wheels, then the vehicle can turn when the steering device is anomalous, but the self-aligning torque prevents the vehicle from turning in accordance with a request

Engineering Contradiction:

Improveturning capability when steering device is anomalousVSAvoidturning accuracy according to request

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent extracts the steering wheel lock mechanism from the normal steering system and uses it as an alternative control path when the front-wheel steering device is anomalous. By locking the steering wheel to prevent self-aligning torque interference, the system isolates the harmful effect and enables turning through differential braking/driving force alone.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using the steering system to turn the vehicle, the patent inverts the approach by using the braking/driving force difference as the primary turning mechanism and the steering wheel lock as the enabling constraint. This reverses the normal control logic where steering is primary and differential force is secondary.

Inventive Principle:

Principle #13The other way round (Inversion)

2Adaptability or versatility

If the steering wheel lock mechanism is activated to disable steering wheel rotation, then the vehicle can turn without self-aligning torque interference, but the steering wheel cannot be used for normal steering control

Engineering Contradiction:

Improveturning capability without self-aligning torque interferenceVSAvoidsteering wheel control availability

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The steering wheel lock mechanism dynamically switches between locked and unlocked states based on the operational status of the front-wheel steering device. When the steering device is normal, the lock is deactivated allowing normal steering. When anomalous, the lock activates to enable alternative turning control, making the system adaptable to different operational conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent activates the steering wheel lock mechanism as a preliminary action before attempting to turn the vehicle when a steering anomaly is detected. This pre-locking prevents self-aligning torque from interfering with the subsequent differential braking/driving force application, ensuring the turning maneuver can proceed without resistance.

Inventive Principle:

Principle #10Preliminary action

3Ease of operation

If the front-wheel steering device is used to steer the front wheels, then normal steering control is available, but the vehicle cannot turn effectively when the steering device is anomalous due to self-aligning torque

Engineering Contradiction:

Improvenormal steering controlVSAvoidturning reliability when steering device is anomalous

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent changes the operational parameters of the steering system by switching from steering wheel rotation control to differential braking/driving force control. This parameter change is enabled by locking the steering wheel, which alters the system's degree of freedom and allows turning through force differential alone, bypassing the anomalous steering device.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The steering wheel lock mechanism acts as an intermediary between the anomalous steering device and the turning control system. By locking the steering wheel, it mediates the conflict between the failed steering device and the alternative turning method, allowing the differential braking/driving force to effectively turn the vehicle without interference from self-aligning torque.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12600405B2Vehicle control device, vehicle control program, and vehicle control method

Publication Date: 2026.04.14 ADVICS CO LTD

AI summary

A vehicle includes vehicle devices configured to adjust a lateral movement amount of the vehicle, and a steering wheel lock mechanism. The vehicle devices include a front-wheel steering device and a remaining device that is a device other than the front-wheel steering device. When there is an anomaly in the front-wheel steering device, a vehicle control device switches a state of the steering wheel lock mechanism from a deactivated state to an activated state. The control device adjusts the amount of lateral movement of the vehicle by activating the remaining device when rotation of the steering wheel is disabled.