Magnetic Tow Coupling Load Sensing Without Structural Weakening

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Solution Overview

Problem

Existing tow coupling systems face challenges in accurately measuring load forces without compromising structural stability, and there is a need for smart tow couplings that provide load weight gauging, shift alerts, and stability control without complex measurement devices or structural weakening.

Innovation Solution

A magneto-elastic based sensor assembly with load sensor pins and magnetic field sensors is used to measure stress and strain, determining the direction and magnitude of load vectors, and includes cryogenic treatment to enhance rigidity and reduce error susceptibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If strain gauges are used for sensing force load on a hitch, then load measurement is achieved, but structural stability of the measuring device is compromised due to required structural weakening

Engineering Contradiction:
Improveload measurementVSAvoidstructural stability
Core Design Contradiction:
Measurement precisionVSStrength

Solution Approach 1:

The patent replaces traditional strain gauge-based mechanical sensing with magneto-elastic sensing. The magneto-elastic sensor uses magnetic field interactions rather than direct mechanical strain measurement, eliminating the need to weaken the hitch structure for sensor installation. The sensor comprises a magneto-elastically active region and a magnetic field sensor means that detects magnetic flux changes caused by applied loads, providing accurate measurement without compromising structural integrity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If complex measurement and control devices are used for smart tow coupling functions, then functionality is improved, but device complexity and cost increase

Engineering Contradiction:
Improvesmart tow coupling functionsVSAvoidmeasurement and control devices
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The magneto-elastic sensor assembly serves multiple functions: it measures load magnitude, determines load direction, and provides data for various smart tow coupling functions including weight distribution monitoring, sway detection, and brake control. This multi-functional approach eliminates the need for separate sensors for each function, reducing overall device complexity while maintaining versatility.

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

Solution Approach 2:

The patent introduces a processor that receives magnetic field sensor signals and computes load characteristics. This intermediary computational element simplifies the overall system by centralizing the measurement and interpretation functions, reducing the need for complex mechanical measurement devices while enabling smart control functions through software processing.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Force

If standard rear-mounted hitch is used for towing, then towing capability is achieved, but vehicle stability and steering ability deteriorate due to weight distribution issues

Engineering Contradiction:
Improvetowing capabilityVSAvoidvehicle stability
Core Design Contradiction:
ForceVSStability of the object's composition

Solution Approach 1:

The magneto-elastic sensor provides real-time feedback on tongue load and weight distribution. This feedback enables the driver to adjust the hitch setup or trailer load distribution to maintain optimal vehicle stability. The sensor continuously monitors the forces on the hitch, allowing for dynamic adjustments to prevent excessive rear axle weight that would compromise steering and handling.

Inventive Principle:
Principle #23Feedback

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

The sensor assembly provides accurate load measurements, reduces drift, and enhances stability by measuring distributed forces on towing vehicles and trailers, enabling improved weight distribution and vehicle control.

Implementation Method 1

The region includes at least one magnetically polarized region such that the magnetic polarization becomes increasingly helically shaped as the applied stress increases

Methodology Applied
Scientific EffectMagneto-elastic effect: Magnetoelastic Effects

Implementation Method 2

The magnetic field sensor means is arranged proximate the at least one magneto-elastically active region and is configured for outputting a signal corresponding to a stress-induced magnetic flux

Methodology Applied
Scientific EffectMagnetic field sensing: Magnetic Field

Implementation Method 3

includes cryogenic treatment to enhance rigidity and reduce error susceptibility

Methodology Applied
Scientific EffectCryogenic treatment: Cryogenics

Data Source

PatentEP3812181B1Towing systems and methods using magnetic field sensing
Publication Date: 2025.11.05 METHODE ELECTRONICS INC
  • EP3812181B1 patent drawingFigure 1~3
  • EP3812181B1 patent drawingFigure 4~6
  • EP3812181B1 patent drawingFigure 7~8

AI summary

A magneto-elastically-based active force sensor, used with a tow coupling between a towed and a towing vehicle or a coupling between a vehicle body and a suspension of the vehicle, which outputs a signal useful for determining forces acting on the coupling. The outputted force information may be provided by processor-enabled embedded software algorithms that take inputs from the force sensor and other sensors, may be used by one or more vehicle systems during operating of the vehicle, such as engine, braking, stability, safety, and informational systems. The force sensor includes directionally-sensitive magnetic field sensing elements inside the sensor, and shielding may be used around the sensors to reduce the influence of external magnetic fields on the sensing elements. The force sensor may be used with different tow and vehicle weight sensing coupling devices installed on different types of automobile cars and trucks.