Steering Feel Consistency via Friction Decoupling

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Solution Overview

Problem

Existing vehicle steering systems often experience unsteadiness and reduced steering feel, especially in long curves, due to frictional forces that vary with operational conditions and mechanical connections, making it difficult to provide a consistent and desired steering experience.

Innovation Solution

A method and system that determine a desired steering device guiding force based on friction models and actual forces, using a feedback controller to adapt the guiding force and decouple the steering feel from mechanical friction, providing a consistent and desired steering feel by applying a final guiding force that compensates for frictional influences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional steering system with mechanical connection is used, then the steering system is simple and reliable, but frictional forces cause unsteady steering feel and reduced steering quality in long curves

Engineering Contradiction:
Improvesteering feel consistencyVSAvoidfrictional forces
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent extracts and eliminates the harmful frictional forces from the steering system by using an actuating device that generates holding torque to counteract friction. The friction compensation unit separately compensates for friction in the steering column, separating the friction problem from the mechanical connection itself.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent implements feedback control through a friction compensation unit that continuously monitors steering operations and adjusts the holding torque generated by the actuating device to compensate for frictional forces, ensuring consistent steering feel throughout long curves and varying operational conditions.

Inventive Principle:
Principle #23Feedback

2Reliability

If friction compensation is implemented to improve steering feel, then steering consistency is improved, but device complexity increases

Engineering Contradiction:
Improvesteering feel consistencyVSAvoidsteering system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The actuating device serves multiple functions: it generates holding torque to counteract friction, assists with steering operations, and integrates with the existing mechanical steering connection. This multi-functionality reduces the need for separate friction compensation mechanisms, thereby limiting the increase in device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Stability of the object's composition

If the steering system compensates for friction to maintain steady steering feel, then steering quality in long curves is improved, but the system requires more complex control mechanisms

Engineering Contradiction:
Improvesteering steadinessVSAvoidcontrol system complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The friction compensation unit automatically adjusts the holding torque based on steering operations without requiring complex external control intervention. The actuating device self-regulates to maintain steady steering feel, reducing the burden on external control systems and simplifying overall control complexity.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2857286B2A method and a system for assisting a driver of a vehicle during operation
Publication Date: 2024.10.16 VOLVO TRUCK CORP
  • EP2857286B2 patent drawingFigure 1
  • EP2857286B2 patent drawingFigure 2~3

AI summary

The invention relates to a method for assisting a driver of a vehicle during operation by providing the driver with a desired steering feel, characterized by the steps of - determining a desired steering device guiding force comprising a part representing a desired friction in a steering arrangement, and - providing the driver with the desired steering feel based on the determined steering device guiding force.