Steering Motor Winding Control for Safe Generator Torque Recovery

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Solution Overview

Problem

Existing steering system motors in motor vehicles face issues with generator operation, where generated electrical currents can cause damage to electronic components due to inadequate design of DC voltage sources and connections, particularly for cost reasons.

Innovation Solution

A method for operating a steering system motor with separate control of two winding groups, where one group is connected to a vehicle battery to absorb negative currents and the other to a traction battery via a unidirectional DC-DC converter, allowing torque redistribution to manage and limit negative current flow, preventing damage to electronic components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the steering system motor is operated in generator mode to enable energy recovery, then energy efficiency is improved, but negative currents can cause damage to electronic components

Engineering Contradiction:
Improveenergy recoveryVSAvoiddamage to electronic components
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The steering system motor is divided into two independently controllable winding groups (first and second winding groups), each capable of being controlled separately by their own circuit arrangements. This segmentation allows the system to direct generator operation to one winding group while protecting the other, enabling energy recovery without exposing all electronic components to negative current damage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A torque distribution unit is introduced as an intermediary component that manages torque distribution between the two winding groups. This mediator directs torque requests to appropriate winding groups based on their operational status, ensuring that generator operation is controlled and that negative currents are managed safely without damaging electronic components.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If two separately controllable winding groups are provided in the steering system motor, then reliability is improved through redundancy, but device complexity increases

Engineering Contradiction:
ImproveredundancyVSAvoidcircuit arrangement complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control functions for the two winding groups are merged into a single integrated torque distribution unit that manages both winding groups. This unified control approach reduces overall system complexity compared to having completely separate control systems, while still maintaining the reliability benefits of redundant winding groups.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Both winding groups are designed with multi-functionality, capable of operating in both motor mode and generator mode. This universality allows the system to use either winding group for different functions as needed, reducing the need for additional specialized components and simplifying the overall system architecture while maintaining reliability.

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

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 method effectively reduces and manages negative current flow, protecting electronic components and ensuring safe generator operation by redirecting currents to the vehicle battery and limiting them in the traction battery system, thus preventing damage.

Implementation Method 1

the first DC voltage source absorbs energy generated by the first winding group during generator operation of the steering system motor

Methodology Applied
Scientific EffectBattery charging: Battery (electricity)

Implementation Method 2

in generator operation, the steering system motor applies a steering resistance torque to the steering handle

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4711240A1Method for operating a steering system motor in motor and generator operation, steering system with steering system motor and motor vehicle with steering system
Publication Date: 2026.03.18 THYSSENKRUPP PRESTA AG
  • EP4711240A1 patent drawingFigure 1~3
  • EP4711240A1 patent drawingFigure 4
  • EP4711240A1 patent drawingFigure 5

AI summary

The present invention relates to a method for operating a steering system motor (1) in a motor vehicle, wherein the steering system motor (1) influences the steering behavior of a steering handle by means of motor operation or generator operation, wherein the steering system motor (1) comprises a first and a second winding group (11, 12), wherein the first winding group (11) is controlled separately from each other via a first circuit arrangement with an associated first control unit (3) and the second winding group (12) is controlled separately from each other via a second circuit arrangement with an associated second control unit (4), wherein the first circuit arrangement is connected to a first DC voltage source (5) and the second circuit arrangement is connected to a second DC voltage source (6).For a torque to be provided by the steering system motor (1) that requires generator operation of the steering system motor (1), a torque redistribution takes place between the first and the second winding group (11, 12), wherein the first winding group (11) is controlled differently from the second winding group (12), and a larger negative current flow is permitted with respect to the first winding group (11) than with respect to the second winding group (12). Furthermore, the invention relates to a steering system with a steering system motor (1) operable according to this method and to a motor vehicle with such a steering system.