Steering Device Arbitration Unit for Dynamic Wheel Lock Angle

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Solution Overview

Problem

Conventional steering devices for rear-axle steering require significant design effort and do not effectively adapt the wheel lock angle to various driving conditions, such as vehicle speed and driver input, which can impact vehicle stability and agility.

Innovation Solution

A steering device with an arbitration unit and a second determination unit that modify the steering angle setpoint based on driver specifications and vehicle dynamics, using a scaling factor to reduce the driver's share and adjust the wheel guide element travel, allowing for independent steering of rear or front wheels and improved adaptability to driving conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional steering devices use electromechanical or electrohydraulic control to adjust wheel lock angle, then the wheel steering function is achieved, but the design effort and system complexity increase considerably

Engineering Contradiction:
Improvewheel lock angle adjustmentVSAvoiddesign effort
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The steering control unit is divided into multiple functional modules: a first determination unit for basic steering function, an arbitration unit for handling conflicts between different steering requests, and a second determination unit for actuator path control. This segmentation allows each module to handle specific tasks independently, reducing overall system complexity while maintaining adaptability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The arbitration unit acts as an intermediary between the first determination unit (basic steering function) and the second determination unit (actuator path control). It receives steering angle setpoints from both sources, resolves conflicts according to predefined arbitration rules, and generates a final steering angle setpoint. This intermediary structure simplifies the control architecture by providing a clear separation of concerns.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the steering angle setpoint is directly used for actuator control, then the basic steering function is maintained, but the system cannot adapt to different driving conditions and vehicle dynamics

Engineering Contradiction:
Improveadaptation to driving conditionsVSAvoidcontrol structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The arbitration unit dynamically adjusts the weighting between different steering angle setpoints based on current driving conditions. It calculates a first weighting factor and a second weighting factor that sum to 1, allowing the system to adaptively prioritize either the basic steering function or the vehicle dynamics correction based on the situation. This dynamic weighting mechanism enables adaptability without requiring a completely restructured control system.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the parameter of steering angle setpoint by combining multiple setpoints with dynamically adjusted weighting factors. The arbitration unit modifies the final steering angle setpoint based on vehicle speed, steering angle, and other driving conditions, allowing the system to adapt to different scenarios while maintaining a consistent control structure.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If the arbitration unit dynamically adjusts weighting factors based on vehicle speed and steering angle, then steering precision is improved, but the control algorithm complexity increases

Engineering Contradiction:
Improvesteering angle precisionVSAvoidcontrol algorithm
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The arbitration unit dynamically changes the weighting parameters (first weighting factor and second weighting factor) based on real-time vehicle speed and steering angle measurements. This allows the system to prioritize different control objectives under different driving conditions, improving steering precision without requiring a fundamentally complex control algorithm.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The arbitration unit continuously receives feedback from sensors measuring vehicle speed and steering angle, and uses this feedback to dynamically adjust the weighting factors. This closed-loop feedback mechanism enables precise steering control by adapting the control strategy to current driving conditions while maintaining a relatively simple algorithmic structure.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2164746B1Steering device for adjusting a wheel steering angle
Publication Date: 2012.08.15 CONTINENTAL TEVES AG & CO OHG
  • EP2164746B1 patent drawingFigure 1
  • EP2164746B1 patent drawingFigure 2~3
  • EP2164746B1 patent drawingFigure 4~5

AI summary

According to an embodiment of the invention, a steering device for adjusting a wheel steering angle of a wheel of a motor vehicle is provided, comprising a wheel guide member (15) and a steering control unit. The steering control unit comprises a basic steering function and an actuator path regulation for adjusting a path of the wheel guide member based on a steering angle target value.