Vehicle Combination Motion Estimation Using Coupling Forces

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Solution Overview

Problem

The absence of real-time state measurement for trailing units in vehicle combinations, particularly lacking data on accelerations, coupling forces, and articulation angles, poses significant safety concerns by hindering the driver's ability to ensure a safe envelope of motion, leading to potential hazardous incidents.

Innovation Solution

A computer system with processing circuitry that acquires parameters from a first unit of a vehicle combination, determines articulation angle and coupling forces between units, and estimates longitudinal and lateral accelerations of the second unit, providing a redundant 'soft' IMU system for backup and fault detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If real-time state measurement for trailing units is implemented, then safety and reliability of vehicle combinations improve, but device complexity and cost increase

Engineering Contradiction:
ImprovesafetyVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent creates a virtual copy of the IMU system by using mathematical models and data from the leading unit to estimate the state of the trailing unit. Instead of installing a physical IMU on the trailing unit, the system computes equivalent motion parameters through calculations based on coupling forces, articulation angles, and kinematic relationships, providing a redundant measurement system without additional hardware.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent introduces an intermediary computational system that processes data from the leading unit's IMU and uses vehicle dynamics models to derive trailing unit state information. This intermediary layer translates leading unit measurements into estimates of trailing unit parameters through mathematical relationships involving coupling forces and articulation geometry.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If state measurement for trailing units is available, then ability to detect and measure motion parameters improves, but system complexity increases

Engineering Contradiction:
Improvemeasurement precisionVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical IMU system on the trailing unit with a computational approach using mathematical models. The system substitutes physical sensors with calculations based on Newtonian mechanics, using forces, masses, and geometric relationships to compute acceleration and orientation parameters that would otherwise require dedicated sensors.

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

Solution Approach 2:

The patent makes the leading unit's IMU system serve multiple functions by using its data not only for controlling the leading unit but also for estimating the state of the trailing unit. This multi-functional use of existing sensors eliminates the need for separate measurement systems while maintaining measurement precision.

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

3Reliability

If redundant measurement systems are implemented, then fault detection capability improves, but device complexity increases

Engineering Contradiction:
Improvefault detectionVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements feedback by continuously comparing the IMU measurements from the leading unit with the computationally derived estimates of trailing unit state. This feedback loop enables fault detection by identifying inconsistencies between direct measurements and model-based estimates, allowing the system to detect sensor failures or model inaccuracies.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-diagnosis by using its own computational model to verify the consistency of sensor measurements. The trailing unit state estimation serves as a self-check mechanism that can identify faults in the measurement system without requiring external verification equipment.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4574611B1Motion information for vehicle combinations
Publication Date: 2026.04.15 VOLVO TRUCK CORP
  • EP4574611B1 patent drawingFigure 1
  • EP4574611B1 patent drawingFigure 2~3
  • EP4574611B1 patent drawing

AI summary

A computer system comprising processing circuitry configured to acquire a first set of parameters relating to a first unit of a vehicle combination, the first set of parameters comprising a longitudinal acceleration of the first unit, a lateral acceleration of the first unit, a yaw rate of the first unit, and a first distance between the centre of gravity of the first unit and a coupling point between the first unit and a second unit of the vehicle combination, acquire a second set of parameters relating to the second unit, the second set of parameters comprising a longitudinal tyre force of the second unit, a mass of the second unit, and a second distance between the centre of gravity of the second unit and the coupling point, acquire a longitudinal coupling force and a lateral coupling force between the first unit and the second unit, and determine an articulation angle between the first unit and the second unit based on the acquired first set of parameters, second set of parameters, longitudinal coupling force, and lateral coupling force.