Trailer Electric Drive Control for Tractor Wheel Slip Support

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Solution Overview

Problem

Existing systems for supporting a towing vehicle in case of loss of traction often require additional hardware and inefficiently interact with other vehicle components, leading to limited support in safety-critical situations, and can affect driver comfort and safety.

Innovation Solution

A method that uses the existing brake control unit of the towing vehicle to determine differential slip and generate an acceleration request, which is transmitted to the trailer's brake control unit to provide support through the trailer's electric drive, minimizing additional hardware requirements and enhancing communication between vehicles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the drive torque of the drive axle is reduced to restore traction, then the loss of traction is prevented, but the driver's acceleration request is not fully implemented, reducing driver comfort

Engineering Contradiction:
Improvetraction controlVSAvoiddriver comfort
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The trailer vehicle acts as an intermediary to transfer driving force to the towing vehicle during loss of traction. The trailer's driven wheels push against the road surface, and through the drawbar connection, this force is transmitted to the towing vehicle, assisting it in overcoming the slippery road conditions without requiring torque reduction that would compromise driver comfort

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The trailer vehicle provides a counterbalancing force through its driven wheels that opposes the harmful effect of the towing vehicle's wheel spin. By generating forward force through the trailer's propulsion system, the system compensates for the traction loss and maintains the driver's intended acceleration while preventing skidding

Inventive Principle:
Principle #8Anti-weight (Counterweight)

2Reliability

If additional interfaces or sensors are added to achieve high integration of system solutions, then support capability is improved, but device complexity and hardware expenditure increase significantly

Engineering Contradiction:
Improvesystem integrationVSAvoidhardware requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The trailer vehicle's existing electric drive system, originally designed for independent propulsion, is made multi-functional by enabling it to also assist the towing vehicle during loss of traction. The same electric motors and control systems serve both as primary propulsion for the trailer and as an assistance system for the towing vehicle, eliminating the need for dedicated assistance hardware

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

Solution Approach 2:

The trailer vehicle's electric drive system is already self-contained with its own energy storage device, converters, and control units. By utilizing this existing self-service infrastructure, the system can provide assistance to the towing vehicle without requiring additional external power sources or complex integration of separate assistance systems

Inventive Principle:
Principle #25Self-service

3Force

If the trailer vehicle is heavily loaded, then power transfer from trailer wheels to road is improved, but the towing vehicle is more likely to experience loss of traction

Engineering Contradiction:
Improvepower transferVSAvoidtraction stability
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The trailer vehicle serves as a force intermediary that leverages its heavy load and good traction to generate propulsive force. This force is then transmitted through the drawbar connection to the towing vehicle, effectively transferring the trailer's superior traction capability to assist the towing vehicle that is experiencing wheel spin on slippery surfaces

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This approach allows for effective support of the towing vehicle during loss of traction with minimal additional hardware, improving safety and comfort by ensuring the trailer provides necessary traction assistance while maintaining vehicle stability and adhering to the driver's acceleration requests.

Implementation Method 1

a loss of traction of the towing vehicle is therefore more likely than that of the trailer vehicle in the described case

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4003771B1Method of assisting the tractor traction of a tractor-trailer vehicle
Publication Date: 2024.07.24 ZF CV SYST GLOBAL GMBH
  • EP4003771B1 patent drawingFigure 1
  • EP4003771B1 patent drawingFigure 2

AI summary

The invention relates to a method for supporting a traction vehicle (12) in the event of traction loss (102) by means of a trailer vehicle (16), comprising the steps: determining (90) a differential slip (92) between at least one driven wheel (20a) and at least one non-driven wheel (20b) of the traction vehicle (12) by means of a brake control device (32) of the traction vehicle (12), which differential slip is above a predefined threshold value (100); and generating (108) an acceleration request (46) depending on the determined differential slip (92) in the brake control device (92) of the traction vehicle (12). The method furthermore comprises the steps: transferring (118) the acceleration request (46) to a trailer brake control device (48) of the trailer vehicle (16); generating (120) a control signal (60) for an electrical drive (52) of the trailer vehicle (16) depending on the acceleration request (46) in the trailer brake control device (48); transferring (140) at least one control signal (60) from the trailer brake control device (48) to the at least one electrical drive (52) of the trailer vehicle (16); and generating (138) at least one drive torque (139) by means of the electrical drive (52) depending on the control signal (60). The invention furthermore relates to a traction vehicle (12) and a trailer vehicle (16) for carrying out the method, and a combination (10) of a traction vehicle (12) and a trailer vehicle (16). The invention additionally relates to a computer program product for carrying out the steps of the method.