Tractor-Trailer Angle Sensing for Uneven-Terrain Trajectory Control

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Solution Overview

Problem

Existing rolling assemblies comprising a tractor unit and a trailer struggle to accurately track the trailer's trajectory in complex environments with uneven terrain or variable traction, particularly for military vehicles operating in rugged conditions.

Innovation Solution

A method for piloting a rolling assembly that measures the angle of rotation of the trailer relative to the towing vehicle using direct distance sensors, independent of wheel rotational speed, and adjusts the trailer's trajectory through electric motors on the drive wheels to match the tractor unit's trajectory.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the trailer trajectory is controlled by adapting engine torque based on wheel rotation speed, then the control system is simple, but the trajectory tracking accuracy deteriorates in complex environments with variable traction

Engineering Contradiction:
Improvetrailer trajectory tracking accuracyVSAvoidcontrol system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical measurement method (indirect calculation from wheel rotation speed) with an optical/electronic measurement method (direct measurement using sensors such as LIDAR, cameras, or GPS). This substitution enables accurate trajectory tracking independent of wheel traction conditions, resolving the contradiction between measurement precision and device complexity by using modern sensing technology that provides direct geometric measurement rather than mechanical inference.

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

Solution Approach 2:

The patent introduces an intermediary measuring device (sensor system) that directly measures the angle of rotation between tractor and trailer. This intermediary provides accurate geometric data that mediates between the physical connection (coupling) and the control system, enabling precise trajectory control without relying on wheel rotation measurements that are affected by traction variations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If indirect calculation based on wheel rotation is used to determine trailer angle, then the device complexity is low, but the measurement precision deteriorates when wheel traction is not constant

Engineering Contradiction:
Improvetrailer rotation angle measurement accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical inference method (calculating angle from wheel rotation speed) with direct optical/electronic measurement using sensors. This substitution eliminates the dependency on wheel traction conditions, as the new system directly measures the geometric angle between tractor and trailer using light-based or electromagnetic-based sensing technology, thereby achieving high measurement precision without mechanical coupling to the wheel rotation.

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

Solution Approach 2:

The patent introduces an intermediary measuring device (sensor system comprising LIDAR, cameras, or GPS) that directly measures the trailer rotation angle. This intermediary provides accurate geometric measurement that mediates between the physical connection and the control system, enabling precise angle determination independent of wheel traction conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the trailer operates on uneven terrain with variable traction, then the vehicle versatility is improved, but the trajectory tracking reliability deteriorates

Engineering Contradiction:
Improveoperation capability in complex environmentsVSAvoidtrailer trajectory tracking reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent replaces the mechanical measurement approach (wheel rotation-based calculation) with optical/electronic sensing technology that is insensitive to traction conditions. This substitution enables reliable trajectory tracking on uneven terrain, as the sensor-based measurement directly captures the geometric relationship between tractor and trailer without being affected by wheel slip or variable ground friction.

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

Solution Approach 2:

The patent introduces an intermediary measuring device that directly measures the trailer angle relative to the tractor. This intermediary provides reliable geometric data that mediates between the variable traction conditions and the control system, enabling consistent trajectory tracking reliability across diverse terrain conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4119428B1Wheeled assembly comprising a tractor vehicle and a trailer and method for controlling such a wheeled assembly
Publication Date: 2025.11.05 ARQUUS
  • EP4119428B1 patent drawingFigure 1
  • EP4119428B1 patent drawingFigure 2

AI summary

This rolling assembly (10) comprises at least one tractor unit (12) including at least two steering wheels (16) and a steering angle sensor (20) for the steering wheels, and a trailer (30) configured to be coupled to the tractor unit by means of a coupling (38), the trailer comprising at least two drive wheels (34), each drive wheel comprising an electric motor (36) controlled by a control unit (22). The rolling assembly also includes a device (50) for measuring the rotation angle (β) of the trailer relative to the tractor unit, and the control unit is configured to correct the trajectory of the trailer by modifying the control input of the electric motor of each drive wheel of the trailer according to the steering angle (α) of the tractor unit's steering wheels and according to the rotation angle (β) of the trailer relative to the tractor unit.