Vehicle Yaw Rate Calculation Using Steering Wheel Rotation

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Solution Overview

Problem

Existing vehicle control systems, such as ESC systems, fail to accurately estimate the desired yaw rate of a vehicle in severe situations of yaw instability, leading to potential loss of control during events like severe skidding.

Innovation Solution

A method that calculates the desired yaw rate based on the rate of steering wheel rotation and the vehicle's actual yaw rate, providing this value as input to the vehicle movement control system, allowing for faster and safer control during severe yaw instability situations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional angle-based methods are used to calculate desired yaw rate, then the calculation is based on steering wheel angle, but the response time is slow (0.6 seconds) and inaccurate in severe yaw instability situations

Engineering Contradiction:
Improvedesired yaw rate estimation accuracyVSAvoidcalculation response time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent changes the input parameter from steering wheel angle to steering wheel rotation rate. This parameter transformation enables the system to capture dynamic steering intentions more effectively, achieving both faster response (0.2 seconds) and improved accuracy in severe yaw instability situations where traditional angle-based methods fail.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If steering wheel angle is used as input, then the system can determine desired yaw rate, but the system fails in severe situations of yaw instability

Engineering Contradiction:
Improvecontrol system reliabilityVSAvoidperformance across different driving situations
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent transitions from a static parameter (steering wheel angle) to a dynamic parameter (steering wheel rotation rate). This dynamic approach allows the system to adapt to severe yaw instability situations by capturing the rate of change in driver intention, significantly improving reliability when traditional methods fail.

Inventive Principle:
Principle #15Dynamics

3Productivity

If the calculation method is simplified to use steering wheel rotation rate, then the response time decreases to 0.2 seconds, but the calculation must accurately capture driver intention

Engineering Contradiction:
Improvecalculation speedVSAvoiddriver intention detection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent uses steering wheel rotation rate as a feedback signal that directly reflects driver intention during yaw instability. By monitoring how quickly the driver rotates the steering wheel, the system inf desired yaw rate with both high speed (0.2 seconds) and high accuracy, capturing the dynamic nature of driver correction actions.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2964502B1Method for calculating a desired yaw rate for a vehicle
Publication Date: 2019.05.08 VOLVO TRUCK CORP
  • EP2964502B1 patent drawingFigure 1
  • EP2964502B1 patent drawingFigure 2
  • EP2964502B1 patent drawingFigure 3

AI summary

The present invention relates to a method for calculating a driver's desired yaw rate of a vehicle (100) for use in a vehicle movement control system (220), comprising the steps of, determining the current yaw rate of the vehicle, determining the rate of the vehicle's steering wheel (110) rotation. The method further comprises the steps of calculating a first desired yaw rate of the vehicle (100) based on said determined current yaw rate of the vehicle and said determined rate of the vehicle's steering wheel (110) rotation, the desired yaw rate being further calculated based on the assumption that the driver applies a rate of steering wheel rotation as function of the driver's perceived error in yaw rate, and finally the step of providing said first desired yaw rate as an input to said vehicle movement control system (220) for controlling the vehicle.