Wheel Steering Angle Determination via Force Feedback

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Solution Overview

Problem

Current methods for determining the current wheel steering angle of a motor vehicle are not precise and reliable, especially under varying environmental conditions such as different friction levels between the tires and the road surface.

Innovation Solution

A method that involves detecting the steering angle using a sensor device and applying a correction value based on the force acting on the steering system during a maneuver, which is determined using force sensors and torque measurements, to accurately calculate the actual wheel steering angle by accounting for environmental factors like friction, temperature, and road conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a predetermined mapping rule is used to determine the wheel steering angle from the steering angle, then the determination process is simple, but the precision is insufficient under varying environmental conditions

Engineering Contradiction:
Improvewheel steering angle determination precisionVSAvoiddetermination system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements feedback by measuring the actual force acting on the steering system during maneuvering and using this measurement to correct the expected wheel steering angle. The control device continuously monitors the force via force sensors and adjusts the steering angle determination based on the deviation between expected and actual force, thereby improving precision while maintaining a relatively simple system architecture.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the parameter used for correction from static mapping rules to dynamic force measurements. By introducing force as a variable parameter that changes with environmental conditions (friction, temperature, road surface), the system adapts the wheel steering angle determination to current conditions, improving precision without requiring complex recalibration of the entire system.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If force sensors and torque measurements are added to account for environmental factors, then the determination reliability improves, but the device complexity increases

Engineering Contradiction:
Improvewheel steering angle determination reliabilityVSAvoidsensor system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the force sensors and torque measurement systems serve multiple functions: they not only correct the wheel steering angle determination but also provide information about road conditions, friction levels, and vehicle maneuvering characteristics. This multi-functionality justifies the added complexity by extracting maximum value from the sensor investments across different operational contexts.

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

Solution Approach 2:

The patent introduces the force measurement as an intermediary between the steering input and the wheel steering angle output. Rather than directly mapping steering angle to wheel angle, the force measurement acts as a mediator that accounts for environmental factors, allowing the system to bridge the gap between expected and actual wheel positioning under varying conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If correction values based on force measurements are applied, then the accuracy under varying friction conditions improves, but the computational complexity increases

Engineering Contradiction:
Improvewheel steering angle accuracy under varying frictionVSAvoidcomputational processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent performs preliminary action by pre-establishing the relationship between force measurements and correction values through the mapping rule. Rather than performing complex real-time calculations to determine correction factors, the system has pre-computed the force-to-angle relationships, allowing for simple lookup and application of correction values during actual operation, thereby reducing computational complexity while maintaining accuracy.

Inventive Principle:
Principle #10Preliminary action

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

This approach allows for precise and reliable determination of the current wheel steering angle, enabling more accurate vehicle positioning and movement, even under challenging conditions, and supports semi-autonomous or autonomous vehicle maneuvering.

Implementation Method 1

a steering angle, which is specified by means of a steering device of the motor vehicle after a steering maneuver has been carried out, is detected by means of a sensor device

Methodology Applied
Scientific EffectSensor detection:

Implementation Method 2

a force acting on a steering is determined during the steering maneuver, with the steering transmitting a torque from the steering device to the steerable wheels

Methodology Applied
Scientific EffectForce sensing:

Data Source

PatentEP3165424B1Method for determining a wheel steering angle of steerable wheels of a motor vehicle, taking into account the torque, control device, driver assistance system and motor vehicle
Publication Date: 2018.08.22 VALEO SCHALTER & SENSOREN GMBH
  • EP3165424B1 patent drawingFigure 1
  • EP3165424B1 patent drawingFigure 2
  • EP3165424B1 patent drawing

AI summary

The invention relates to a method for determining the current wheel steering angle (αt) of steerable wheels (4) of a motor vehicle (1), in which a steering angle (ϕ), which is specified by means of a steering device (6) of the motor vehicle (1) after a steering maneuver has been carried out, is detected by means of a sensor device (11) and the expected wheel steering angle (αe) is determined on the basis of a predetermined mapping specification which describes a dependence of an expected wheel steering angle (αe) on the steering angle (ϕ), wherein a force (F) acting on a steering system (7) of the motor vehicle (1) during the steering maneuver is determined, wherein the steering system (7) transmits a torque from the steering device (6) to the steerable wheels (4), and a correction value for correcting the expected wheel steering angle (αe) is determined on the basis of the determined force (F).