Self-Steering Trailer Axle Control via Path Radius Calculation

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Solution Overview

Problem

Existing methods for tracking multi-axle trailers behind towing vehicles are limited in their ability to maintain independent steering and stability, especially when forces are applied to the drawbar, and often require sensors from the towing vehicle to calculate steering angles.

Innovation Solution

A method and device that calculate the path radius of the trailer using sensor values from sensors on the trailer, setting the target angle based on the center distance between axles, allowing self-controlled steering independent of the towing vehicle, with optional use of a single sensor device to determine angular velocity and path speed, and additional sensors for increased accuracy and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If sensor values from the towing vehicle are used to calculate trailer steering angles, then the tracking precision can be improved, but the device complexity and dependency on towing vehicle sensors increases

Engineering Contradiction:
Improvetracking precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the steering control functionality from the towing vehicle system and relocates it to the trailer system. The trailer now independently calculates its own steering angles using sensors mounted on the trailer, eliminating dependency on towing vehicle sensors and reducing overall system complexity while maintaining tracking precision

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The trailer system performs self-steering by using its own sensors to detect movement values and calculate steering angles independently. This self-service approach eliminates the need for external sensor data from the towing vehicle, reducing device complexity while maintaining control precision

Inventive Principle:
Principle #25Self-service

2Measurement precision

If multiple sensors are used to determine angular velocity and track speed, then the measurement precision increases, but the device complexity and cost increases

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

Solution Approach 1:

The patent employs a single multi-functional sensor device that simultaneously measures both angular velocity and track speed. This universal sensor approach provides the measurement precision of multiple sensors while reducing device complexity and cost by consolidating functions into one device

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

3Adaptability or versatility

If the trailer is designed to steer independently without towing vehicle sensors, then the adaptability to different towing vehicles increases, but the reliability of tracking may be affected

Engineering Contradiction:
ImproveadaptabilityVSAvoidtracking reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The trailer system achieves universal adaptability to different towing vehicles through self-steering capability. By using its own sensors and independent calculation of steering angles, the trailer can be coupled with various towing vehicles without requiring sensors from the towing vehicle, maintaining both adaptability and tracking reliability

Inventive Principle:
Principle #25Self-service

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

Enables the trailer to steer independently in various situations, maintain stability, and be coupled with different towing vehicles without requiring sensors from the towing vehicle, improving load-carrying capacity and safety by determining impending tipping.

Implementation Method 1

the angular velocity of the trailer is determined by a yaw rate sensor

Methodology Applied
Scientific EffectYaw rate sensing:

Implementation Method 2

the track speed is detected by at least one speed sensor on an axle

Methodology Applied
Scientific EffectSpeed sensing:

Data Source

PatentEP3994047B1Method and device for the optimized adjustment of a multi-axle trailer behind a tractor vehicle
Publication Date: 2024.04.03 HYDAC SOFTWARE GMBH
  • EP3994047B1 patent drawingFigure 1
  • EP3994047B1 patent drawingFigure 2
  • EP3994047B1 patent drawing

AI summary

1. The invention discloses a method for the optimized adjustment of a multi-axle trailer (10) behind a tractor vehicle (14), which trailer and tractor vehicle are connected to one another by means of a detachable coupling device (12) which can be coupled rigidly, said method being characterized in that by means of at least one sensor device (34, 38) arranged on the trailer (10), the angular speed (ψAn) and the trajectory velocity (ν An ) of the trailer (10) are determined as sensor values, and a path radius (RAn) is calculated for the trailer (10) by a computer unit (42) as a function of these sensor values, and in that the path radius (RAn) is placed in an angular relationship with the axle base (I) between two adjacent trailer axles (16, 18) and yields a setpoint angle (γ), and as a function thereof at least one steering axle (16) of the trailer (10) is actuated, which trailer can in this way be coupled to various types of tractor vehicles (14) in a self-steering-enabled fashion and/or within the scope of the formation of a tractor-trailer combination.