Towing Trailer Articulation Angle Estimation Using Wheel Speed Geometry

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Solution Overview

Problem

Existing methods for determining the articulation angle between a towing vehicle and a trailer are costly and prone to errors due to the use of articulation angle sensors.

Innovation Solution

Estimate the articulation angle based on wheel speeds of the towing vehicle and trailer, using existing sensors for wheel speed data, and geometric parameters of the vehicle and trailer, without relying on direct articulation angle sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an articulation angle sensor is used to directly measure the articulation angle, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:

Improvearticulation angle measurement precisionVSAvoidsensor system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses wheel speed sensors as intermediary measurement points to indirectly determine the articulation angle. Instead of directly measuring the articulation angle with a dedicated sensor, the system measures wheel speeds at different locations and uses these as intermediate data to calculate the articulation angle through geometric relationships and kinematic equations.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical articulation angle sensor with a computational approach using wheel speed data. The mechanical measurement system is substituted by an electronic calculation system that processes wheel speed signals from existing sensors to derive the articulation angle through mathematical models involving instantaneous centers of velocity and geometric parameters.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If an articulation angle sensor is used to directly measure the articulation angle, then measurement precision is improved, but cost increases

Engineering Contradiction:

Improvearticulation angle measurement precisionVSAvoidsystem cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent uses existing wheel speed sensors that are already part of the vehicle's brake control or speed measurement systems. These sensors are relatively inexpensive and already deployed for other functions, eliminating the need to install expensive dedicated articulation angle sensors while maintaining measurement capability through computational methods.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent makes existing wheel speed sensors serve multiple functions: their primary function for brake control or speed measurement, and a secondary function for articulation angle determination. This multi-functionality eliminates the need for additional dedicated sensors, reducing overall system cost while maintaining articulation angle measurement capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Device complexity

If wheel speed sensors are used to estimate the articulation angle, then device complexity is reduced, but measurement precision may worsen

Engineering Contradiction:

Improvesensor system complexityVSAvoidarticulation angle estimation precision

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent employs feedback mechanisms where the estimated articulation angle is continuously refined based on ongoing wheel speed measurements and vehicle motion data. The system uses the calculated articulation angle to validate the consistency of wheel speed measurements and adjusts the estimation process to improve precision over time through iterative calculation and cross-validation.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent transitions from direct one-dimensional angle measurement to a multi-dimensional approach by incorporating wheel speeds from multiple axles and positions, along with geometric parameters and instantaneous center of velocity calculations. This multi-dimensional data fusion compensates for individual measurement uncertainties and improves overall estimation precision.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS12358556B2Method for estimating an articulation angle between a towing vehicle and a trailer, respective device, driving assistance system, commercial vehicle and computer program product

Publication Date: 2025.07.15 KNORR BREMSE SYSTEME FUER NUTZFAHIZEUGE GMBH

AI summary

A method estimates an articulation angle between a towing vehicle and a trailer with respect to a pivot. The method determines a distance between an instantaneous center of velocity of the towing vehicle and a center of at least one axle of the towing vehicle representative for a rotation of the towing vehicle about the instantaneous center of velocity of the towing vehicle and/or a distance between an instantaneous center of velocity of the trailer and a center of at least one axle of the trailer representative for a rotation of the trailer about the instantaneous center of velocity of the trailer. The method determines at least one instantaneous speed representative for a wheel speed of at least one wheel of the towing vehicle and/or the trailer, wherein the at least one instantaneous speed refers to the at least one determined distance, and estimates the articulation angle based on the at least one determined instantaneous speed and the at least one determined distance.