Vehicle Steering Ratio Control via Speed-Dependent Curves

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Solution Overview

Problem

Vehicle-type driving devices experience poor steering feel during turning, affecting the operating experience of users.

Innovation Solution

Implementing a steering ratio curve function that adjusts the steering ratio based on the vehicle's speed, using low-speed and high-speed steering ratio curves, and a control device to set the steering ratio according to the steering angle and speed, enhancing the steering feel by adjusting the vehicle's speed and angular velocity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the vehicle-type driving device decelerates during turning to ensure driving safety, then the safety is improved, but the steering feel deteriorates and operating experience is affected

Engineering Contradiction:
Improvedriving safetyVSAvoidsteering feel
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies dynamics by making the steering ratio variable rather than fixed. The control device dynamically adjusts the steering ratio based on real-time traveling speed feedback, allowing the steering system to adapt its characteristics to different operating conditions. This resolves the contradiction by enabling the system to provide appropriate steering assistance at various speeds without compromising safety.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of steering ratio from a constant value to a variable parameter that depends on traveling speed. By establishing a correspondence between steering ratio and traveling speed, the system can optimize steering feel at different speeds while maintaining safety through controlled deceleration. The control device continuously adjusts this parameter based on speed feedback.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If a fixed steering ratio is used in the vehicle-type driving device, then the structure is simple, but the steering feel is poor during turning

Engineering Contradiction:
Improvesteering system structureVSAvoidsteering feel
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The patent transforms the static steering ratio into a dynamic parameter that varies with traveling speed. The control device receives speed feedback and automatically adjusts the steering ratio accordingly, creating a responsive steering system that adapts to different operating conditions without requiring complex mechanical structures.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements a feedback mechanism where the control device continuously monitors traveling speed and uses this information to adjust the steering ratio. This closed-loop control system ensures optimal steering feel by constantly adapting to the current speed condition, resolving the contradiction between simplicity and performance.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4707131A2Vehicle-type driving device
Publication Date: 2026.03.11 NANJING CHERVON IND
  • EP4707131A2 patent drawingFigure 1
  • EP4707131A2 patent drawingFigure 2
  • EP4707131A2 patent drawingFigure 3

AI summary

Provided is a vehicle-type driving device. The vehicle-type driving device provided in the present application includes a traveling assembly including multiple traveling wheels; a steering wheel configured to control the vehicle-type driving device to steer; a traveling motor for driving the vehicle-type driving device to steer at a target angular velocity, where the ratio of the target angular velocity to the change in the steering angle of the steering wheel is defined as a steering ratio; and a control device configured to, when the traveling speed of the vehicle-type driving device is within a preset range, set the steering ratio according to a steering ratio curve function, where variables of the steering ratio curve function include the steering angle of the steering wheel and the traveling speed of the vehicle-type driving device. In this manner, the steering feel of the vehicle-type driving device at different speeds can be improved, the problem of poor operating feel for a driver driving and turning can be solved, and the operating experience of the user can be improved.