Targetless Hitch Angle Detection for Vehicle-Trailer Backing

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Solution Overview

Problem

Backup maneuvers of trailers attached to vehicles are challenging due to the difficulty in controlling the trailer's path, especially when reversing, often requiring multiple people and causing confusion about steering wheel adjustments, which can lead to trailer jack-knifing and loss of course.

Innovation Solution

A backing system for vehicle and trailer assemblies that uses a camera to record images of the hitch, learns geometry distances and reference points, determines the current hitch angle, and controls vehicle movements through an electronic control unit and control device, allowing single-user operation without external assistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual trailer backing control is used, then the driver has direct control over the vehicle, but the trailer path control becomes difficult and requires multiple operators

Engineering Contradiction:
Improvetrailer path controlVSAvoidnumber of operators required
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The system enables the driver to independently control the trailer backing path without external assistance. The electronic control unit automatically calculates steering commands based on camera images of reference points, allowing the driver to operate the system alone while maintaining precise trailer path control.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical steering control with an automated electronic control system. The electronic control unit processes visual data from the camera and generates automated steering commands, substituting the purely mechanical driver-steering-wheel-trailer control chain with an electro-optical control system that enhances ease of operation.

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

2Reliability

If incorrect steering angle is applied, then the vehicle may move in the desired direction, but the trailer may jack-knife and lose its course

Engineering Contradiction:
Improvetrailer course maintenanceVSAvoidhitch angle detection
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The system continuously captures images of reference points on the trailer and recalculates the hitch angle in real-time during backing operations. This closed-loop feedback mechanism allows the electronic control unit to monitor and adjust the steering angle dynamically, maintaining reliable trailer course while compensating for changes in hitch angle throughout the maneuver.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary learning of trailer geometry and reference point positions before actual backing operations. By pre-storing the hitch angle at straight-ahead position and learning reference point locations, the system establishes a baseline for accurate real-time hitch angle calculation, enabling reliable trailer course maintenance from the start of the backing maneuver.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If traditional backing assistance systems are used, then some guidance is provided, but calibration and setup procedures are complex and time-consuming

Engineering Contradiction:
Improvesystem setupVSAvoidcalibration time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The system automatically learns and stores trailer-specific geometry parameters and reference point positions during a brief initialization phase. This self-calibration capability eliminates the need for complex manual setup procedures, allowing the system to adapt to different trailers automatically and reducing setup time significantly.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent implements preliminary learning procedures that automatically capture and store essential trailer geometry data before normal operation begins. By performing this calibration action in advance during a simplified setup routine, the system prepares all necessary parameters for accurate hitch angle calculation without requiring time-consuming manual adjustments during each use.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3390121B1Vehicle-trailer backing system having targetless hitch angle detection and trailer geometry learning
Publication Date: 2022.03.09 CONTINENTAL AUTOMOTIVE SYSTEMS INC
  • EP3390121B1 patent drawingFigure 1
  • EP3390121B1 patent drawingFigure 2

AI summary

A backing system for a trailer and vehicle and associated method includes recording an image of a hitch for the vehicle and trailer assembly with a camera. A plurality of distances related to geometry of the vehicle and the trailer and a plurality of reference points are learned based on the camera inputs. A plurality of reference distances related to the plurality of reference points are then determined. A current hitch angle may then be determined using the plurality of reference distances and the geometry distances.