Trailer Coupling Articulation Angle Estimation With Sensor Correction

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Solution Overview

Problem

Existing methods for determining the articulation angle between a commercial vehicle and its trailer are inaccurate, especially when reversing, due to limitations in sensor sensitivity and calibration requirements, which affects safety and autonomous driving systems.

Innovation Solution

A method that corrects modeled articulation angles using relative measured values from a yaw rate sensor, incorporating Kalman filtering to iteratively refine the output and account for variance, allowing for robust and precise articulation angle determination without the need for absolute calibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Difficulty of detecting and measuring

If optical sensors or laser systems are used to measure articulation angle directly, then measurement capability is provided, but measurement precision deteriorates due to sensitivity to dirt and limited measuring range

Engineering Contradiction:
Improvearticulation angle measurement capabilityVSAvoidarticulation angle measurement accuracy
Core Design Contradiction:
Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The patent replaces optical measurement systems with a mechanical sensor unit that uses a wheel to physically contact the trailer and detect articulation angle through mechanical rotation. This substitution eliminates the sensitivity issues of optical systems to dirt and light conditions while providing robust mechanical measurement capability

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

Solution Approach 2:

The patent introduces a mechanical wheel as an intermediary between the sensor and the trailer. The wheel contacts the trailer surface and converts articulation angle movements into rotational movements that can be detected by rotation rate sensors, providing indirect but reliable measurement without direct optical line-of-sight requirements

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If mechanical sensor systems are used for articulation angle measurement, then direct measurement is achieved, but device complexity increases due to calibration requirements

Engineering Contradiction:
Improvearticulation angle measurement accuracyVSAvoidcalibration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The mechanical sensor unit is designed to be self-calibrating through its physical contact with the trailer. The wheel naturally aligns with the trailer surface and the rotation rate sensor automatically references the trailer's movement, eliminating the need for manual calibration procedures before each journey

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent uses dynamic measurement through rotation rate sensors that continuously track changes in articulation angle during movement. This dynamic approach allows the system to measure relative movements without requiring absolute calibration, as the sensors detect changes from the current state rather than reference points

Inventive Principle:
Principle #15Dynamics

3Device complexity

If modeled articulation angle is used for autonomous driving, then system simplicity is maintained, but reliability deteriorates during reversing operations

Engineering Contradiction:
Improvesystem simplicityVSAvoidarticulation angle accuracy during reversing
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements feedback by continuously comparing the mechanically measured articulation angle from the sensor unit with the modeled articulation angle from the control device. The mechanical measurement serves as feedback to validate and correct the modeled values, ensuring reliability during reversing when the model alone would be inaccurate

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent merges two approaches: the simple modeled articulation angle calculation from the control device and the direct mechanical measurement from the sensor unit. By combining these methods, the system maintains simplicity through the model while gaining reliability through the mechanical verification, particularly during reversing operations

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3810475B1Method for a utility vehicle which has a trailer coupling, device and utility vehicle for said method, and computer program product for same
Publication Date: 2023.12.13 ZF CV SYST EURO BV
  • EP3810475B1 patent drawingFigure 1~3
  • EP3810475B1 patent drawingFigure 4~5
  • EP3810475B1 patent drawingFigure 6~8

AI summary

The invention relates to a method for a utility vehicle (10), in particular a semi-trailer truck (20), which has a trailer coupling (14), for determining an angle of articulation (28) between the utility vehicle (10) and a towed vehicle trailer (12), in particular a semi-trailer (22). The method first has a step of a) determining a modeled value (54) of an angle of articulation (28) or a change (32) in the angle of articulation using a model (105); in a step b), a measured value (64) of an angle of articulation (28) or a change (32) in the angle of articulation is additionally determined using a sensor unit (34); in a step c), a correction value (76) is then derived from the measured value (64); in a step d), the modeled value (54) is corrected on the basis of the correction value (76); and in step e), the corrected modeled value (58) is then output as an output value (58) of the angle of articulation (28). The invention additionally relates to a device (86) for carrying out the method, to a utility vehicle (10) comprising the device (86), and to a computer program product for same.