Steer-by-Wire Authentication for Post-Failure Maneuvering

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Steer-by-wire systems in motor vehicles lack fault-tolerance, rendering them inoperable in the event of a failure, necessitating immobilization until repair, which is inefficient and inconvenient.

Innovation Solution

A fault-tolerant steer-by-wire system with a primary and secondary steering level, incorporating an authentication system that allows bypassing safety functions, enabling continued maneuvering by authorized personnel using a mechanical fallback or direct electrical intervention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a steer-by-wire system is designed with complete elimination of mechanical connection between steering wheel and steering gear, then the system achieves higher automation and electronic control capability, but the system loses fault-tolerance and becomes inoperable upon failure

Engineering Contradiction:
Improveelectronic control capabilityVSAvoidfault-tolerance
Core Design Contradiction:
Extent of automationVSReliability

Solution Approach 1:

The patent divides the steering system into multiple independent functional modules: primary steering level with steering transmission device, secondary steering level with safety device, and authentication system with terminal device. This modular segmentation allows the system to maintain partial functionality even when certain modules fail, resolving the contradiction between automation and fault-tolerance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements preliminary authentication mechanisms and safety devices before failure occurs. The authentication system verifies authorization status in advance, and the secondary steering level is pre-configured to activate upon primary system failure. This preliminary preparation ensures the system can transition to emergency operation mode without complete loss of functionality.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If a steer-by-wire system implements fail-safe design with mechanical fallback, then the system maintains reliability during failure, but the device complexity increases significantly

Engineering Contradiction:
Improvefault-toleranceVSAvoidsystem structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the essential safety function from the complex mechanical fallback structure and implements it through a simplified secondary steering level with electronic control. Instead of maintaining duplicate complex mechanical systems, the invention extracts only the necessary steering function and implements it through a lighter, more manageable electronic-mechanical hybrid structure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The steering transmission device and safety device share common structural elements and control resources. The secondary steering level can serve both as a fallback mechanism and as a supplemental control system during normal operation. This multi-functionality reduces the need for completely separate systems, thereby reducing overall complexity while maintaining reliability.

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

3Reliability

If a vehicle is switched off after emergency operation to prevent further use of unreliable steering system, then safety is maintained, but the vehicle cannot be maneuvered for towing or transport until repair

Engineering Contradiction:
ImprovesafetyVSAvoidmaneuverability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The authentication system dynamically adjusts system accessibility based on real-time authorization status. After emergency operation, the system does not permanently disable maneuverability but instead implements conditional access control. Authorized personnel can authenticate and temporarily restore maneuverability for towing or transport, while unauthorized access remains blocked. This dynamic control maintains safety while enabling necessary post-emergency operations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The terminal device acts as an intermediary between authorized personnel and the steering system. It mediates access control by verifying authentication codes and temporarily enabling the secondary steering level for authorized users. This intermediary mechanism allows controlled maneuverability restoration without compromising overall system safety, as the authentication process ensures only qualified personnel can activate the system.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of operation

If an authentication system is implemented to allow bypassing safety functions for authorized personnel, then maneuverability is restored post-failure, but the system complexity and security requirements increase

Engineering Contradiction:
ImprovemaneuverabilityVSAvoidauthentication system
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The authentication system uses simple, inexpensive authentication codes that can be easily distributed and invalidated. Rather than implementing complex cryptographic systems or hardware security modules, the patent employs software-based authentication with temporary authorization codes. These codes can be generated, used, and discarded easily, providing adequate security for the specific use case of post-emergency towing operations without excessive complexity.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Data Source

PatentEP3445639B1Transport key for a steer-by-wire steering system for motor vehicles
Publication Date: 2022.07.06 THYSSENKRUPP PRESTA AG
  • EP3445639B1 patent drawingFigure 1~3

AI summary

The invention relates to a steer-by-wire steering system for motor vehicles having a primary steering level with a steering transmission device (4), which is configured in such a way that it applies wheels (6) of the motor vehicle to be steered with a desired target steering force, and a secondary steering level with a security device (7), which provides predefined functions such that, in the event of a failure of the primary steering level, the steering of the wheels (6) remains possible during an emergency operation, wherein the steer-by-wire steering system has an authentication system (9) with a communications interface for communication with the security device (7), and wherein the authentication (9) is configured in such a way that, in the event of a successful authorisation, the secondary steering level of the steer-by-wire steering system is also available after the emergency operation.