Supplemental Trailer Steering with Hitch History Path Tracking

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Solution Overview

Problem

Trailing farm implements veer inwardly during tractor turns, leading to crop damage and soil compaction due to existing steering systems' inefficiencies, including mechanical linkages and calibration issues.

Innovation Solution

A method and system for controlled supplemental steering using a controller, position sensing, and actuation of steerable wheels or a drawbar, updating hitch position history through rotation and translation operations in a reference coordinate system to maintain alignment with the tractor path.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical linkages are used to physically actuate a turning angle measurement device during tractor turns, then the trailer can follow the tractor's path, but additional structures at the hitch point are created that require maintenance

Engineering Contradiction:

Improvetrailer path followingVSAvoidmaintenance of mechanical linkages

Core Design Contradiction:

ReliabilityVSEase of repair

Solution Approach 1:

The patent replaces mechanical linkages with an electronic sensing and control system. Sensors detect the tractor's turning angle and position, and an electronic controller actuates the trailer steering mechanism, eliminating the need for mechanical linkages at the hitch point while maintaining path following capability

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an electronic controller as an intermediary between the sensing system and the steering actuation system. This controller processes sensor data and generates control signals to actuate the trailer steering, replacing the direct mechanical connection approach

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a gyro mounted on the tractor is used to sense changes in direction, then the trailer wheels can be steered to counter veering, but calibration problems arise for different positioning on the tractor

Engineering Contradiction:

Improvetrailer veering counteractionVSAvoidcalibration for different positioning

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The system performs self-calibration by using sensors mounted on the trailer itself to detect the hitch point position and orientation. The controller automatically establishes the reference coordinate system based on actual sensor readings, eliminating the need for manual calibration for different tractor positions

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces the tractor-mounted gyro system with trailer-mounted sensors that directly measure the hitch point dynamics. This substitution eliminates calibration issues related to gyro positioning on the tractor, as the measurement reference is now fixed to the trailer

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Speed

If a tractor-mounted system is used to control trailer steering, then real-time control is achieved, but support for tractor-to-implement communication link is required

Engineering Contradiction:

Improvereal-time control responseVSAvoidcommunication link support

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The patent inverts the control architecture by placing the intelligent controller and sensors on the trailer rather than the tractor. The trailer independently processes its own positioning data and controls its steering, eliminating the need for complex tractor-to-implement communication links while maintaining real-time control

Inventive Principle:

Principle #13The other way round (Inversion)

4Reliability

If steerable wheels are incorporated in the trailer, then the trailer can closely follow the tractor path, but the complexity of the steering system increases

Engineering Contradiction:

Improvetrailer path trackingVSAvoidsteering system structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical steering linkages with an electronic control system that uses sensors to detect hitch point position and orientation. The controller electronically actuates the steerable wheels based on real-time sensor data, achieving precise path tracking with reduced mechanical complexity

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP4149821B1Steering controller and method for steering a tracking path of a trailer

Publication Date: 2026.02.25 SPRAYING SYSTEMS CO

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AI summary

A method and system are described for controlled supplemental steering, by actuating a supplemental steering element, of a trailing implement (20) connectable via a hitch to a pulling source (10), and wherein the trailing implement (20) includes a pair of parallel wheels, a controller, a position sensing system that generates a hitch position history comprising a stored set of recent positions of the hitch point, and a steering angle actuator. The method carried out by the system includes maintaining a history of positions of the hitch, determining a target steering angle for the supplemental steering element, and actuating the steering angle actuator in accordance with the target steering angle. During the maintaining the history of positions of the hitch, the history of positions of the hitch is updated by performing a rotation operation and a translation operation on a set of coordinates of the history corresponding to previous hitch positions.