Steer-by-Wire Torque Feedback for Intuitive Assisted Steering

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Solution Overview

Problem

Steering systems in motor vehicles lack the ability to seamlessly integrate driving assistance systems with a comfortable and intuitive steering experience, particularly in steer-by-wire systems where the steering handle is mechanically decoupled from the wheels.

Innovation Solution

A computing device controls a steering handle actuator and wheel actuator to specify a target manual torque and wheel steering angle based on a target variable, allowing for comfortable and intuitive steering even with active driving assistance systems, using transfer functions and limiting modules to adjust and smooth the steering experience.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the steering handle is mechanically decoupled from the wheel in steer-by-wire systems, then the steering handle actuation becomes independent from wheel steering, enabling flexible control and integration of driving assistance systems, but the steering experience may become less intuitive and comfortable due to loss of mechanical feedback

Engineering Contradiction:

Improveflexibility in control and integration of driving assistance systemsVSAvoidintuitiveness and comfort of steering experience

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The system implements feedback by using sensors to detect the actual position and torque of the steering handle, comparing it with target values, and adjusting the actuator accordingly. This closed-loop control restores the feeling of mechanical connection by ensuring the steering handle responds intuitively to user inputs while maintaining independence from direct mechanical coupling to the wheels.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system changes physical parameters by dynamically adjusting the torque applied to the steering handle through the actuator. By modifying torque magnitude and characteristics based on driving assistance system requirements and user input, the system maintains comfortable steering feedback while enabling flexible, decoupled control architecture.

Inventive Principle:

Principle #35Parameter changes

2Extent of automation

If driving assistance systems are integrated into the steering system, then automated steering functions can be provided, but the steering handle may experience disruptive sensations and reduced comfort due to conflicting control objectives

Engineering Contradiction:

Improveautomated steering functionsVSAvoidcomfort and lack of disruptive sensations

Core Design Contradiction:

Extent of automationVSEase of operation

Solution Approach 1:

The system applies dynamics by making the torque characteristics adaptive and variable rather than fixed. The actuator dynamically adjusts its torque output based on real-time conditions, blending automated steering commands with user input preferences. This allows the system to transition smoothly between automated and manual control modes, preventing disruptive sensations.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The feedback mechanism continuously monitors steering handle torque and position, allowing the system to detect when automated functions conflict with user intentions. By adjusting torque in real-time based on this feedback, the system resolves conflicts between automation and user comfort, ensuring smooth transitions and eliminating disruptive sensations.

Inventive Principle:

Principle #23Feedback

3Ease of operation

If manual torque regulation is implemented based on target variables, then comfortable steering feedback can be provided, but the system complexity increases due to additional control loops and sensors

Engineering Contradiction:

Improvecomfortable steering feedbackVSAvoidcontrol loops and sensors

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The system achieves universality by designing the control loop to serve multiple functions simultaneously. The same torque regulation mechanism provides both comfortable steering feedback and support for driving assistance systems. The sensor suite and control algorithm are configured to handle various operating modes (manual steering, automated functions, transition phases) through a unified approach, reducing overall system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12570355B2Apparatus for a steering system of a motor vehicle, motor vehicle, method for operating a steering system of a motor vehicle

Publication Date: 2026.03.10 ROBERT BOSCH GMBH

AI summary

An apparatus for operating a motor vehicle, wherein the steering system comprises an actuatable steering handle and a steerable wheel, wherein the steering handle is mechanically decoupled from the wheel such that an actuation of the steering handle is independent from a steering of the wheel, wherein the steering handle is associated with a controllable steering handle actuator for generating a torque acting on the steering handle, and wherein the wheel is associated with a controllable wheel actuator for influencing a wheel steering angle of the wheel, with a computing device configured to control the steering handle actuator and the wheel actuator. The computing device is configured to specify a target manual torque (HMTarget) for the steering handle as a function of a target variable specified by a driving assistance system and to control the steering handle actuator as a function of the specified target manual torque (HMTarget).