Single-Axle Dolly Auto-Coupling via Variable Height Suspension

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Solution Overview

Problem

Existing self-powered dolly vehicles require manual intervention for complex and time-consuming coupling procedures, which can be optimized for improved handling and fuel efficiency.

Innovation Solution

A single axle dolly vehicle unit with an electrical energy source powering electric machines for wheel propulsion, equipped with a variable height suspension system and a control unit for auto-coupling, utilizing sensors and remote control capabilities to adjust the fifth wheel connection height and drawbar position for seamless trailer attachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If manual coupling procedure is used, then operator control is maintained, but coupling time and operational complexity increase

Engineering Contradiction:
Improvecoupling speedVSAvoidcontrol system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The dolly vehicle performs coupling operations autonomously without requiring manual intervention. The control unit automatically controls the suspension system to adjust fifth wheel height and position, enabling the vehicle to service itself during coupling procedures, thereby reducing coupling time and operational complexity

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

Manual mechanical coupling operations are replaced with an automated control system that uses sensors to detect trailer position and control signals to operate the suspension system, substituting human-operated mechanical procedures with an electronic control-based system

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

2Extent of automation

If variable height suspension system is added for auto-coupling, then coupling automation is enabled, but device complexity increases

Engineering Contradiction:
Improveauto-coupling capabilityVSAvoidsuspension system complexity
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The variable height suspension system serves multiple functions: it provides ride comfort during normal operation and enables auto-coupling by automatically adjusting the fifth wheel height to match the trailer kingpin height. This multi-functionality justifies the added complexity by eliminating the need for separate coupling mechanisms

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

Solution Approach 2:

The suspension system transitions from a static structure to a dynamic, actively controlled system that can adjust its height in real-time based on coupling requirements, enabling the dolly to adapt its configuration for optimal coupling performance

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If sensors and control systems are integrated, then coupling precision is improved, but manufacturing cost increases

Engineering Contradiction:
Improveheight detection accuracyVSAvoidmanufacturing complexity
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

Sensors detect the position and height of the trailer kingpin and provide feedback to the control unit, which then adjusts the suspension system accordingly. This closed-loop feedback mechanism ensures precise coupling while using standard sensing and control technologies to manage manufacturing complexity

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 solution simplifies the coupling process, enhances fuel efficiency, and improves vehicle handling by enabling autonomous or semi-autonomous trailer attachment, reducing manual intervention and operational complexity.

Implementation Method 1

an electrical energy source arranged to power at least one electric machine configured to drive left and right wheels

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Data Source

PatentEP3995385B1A self-powered single axle dolly vehicle unit with auto-coupling ability
Publication Date: 2025.12.24 VOLVO TRUCK CORP
  • EP3995385B1 patent drawingFigure 1A~1B
  • EP3995385B1 patent drawingFigure 2A
  • EP3995385B1 patent drawingFigure 2B~3

AI summary

A single axle dolly vehicle unit (130) for a heavy duty vehicle combination (100), the dolly vehicle unit (130) comprising an electrical energy source arranged to power at least one electric machine configured to drive left and right wheels of the single axle, the dolly vehicle unit (130) further comprising a drawbar and a fifth wheel connection for mating with first (120) and second (140) trailer units, respectively, wherein the fifth wheel connection is arranged to be adjusted in height over ground (h) by a variable height suspension system, the dolly vehicle unit (130) further comprising a control unit arranged to control the variable height suspension system.