Ship Disturbance Estimation Using Thrust and Navigation Data

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Solution Overview

Problem

Existing methods struggle to accurately and timely estimate disturbances acting on marine vessels, such as wave forces and wind, which interfere with stable control and navigation.

Innovation Solution

A disturbance estimation apparatus and method that utilizes a navigation data receiver, a thrust data receiver, and processing circuitry to estimate a predicted position and arrival time of a ship by inputting navigation and thrust data into a trained model, and determines disturbance data including drift direction and speed based on the difference between predicted and actual positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If position information from GNSS is used to control the ship, then the ship can be positioned and navigated, but disturbance cannot be accurately estimated because it is difficult to distinguish thrust-induced movement from disturbance-induced movement

Engineering Contradiction:

Improvedisturbance estimation accuracyVSAvoidinability to distinguish thrust effect from disturbance effect

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The patent segments the ship's movement into two distinct components: movement due to thrust and movement due to disturbance. By using the trained model to separately estimate these components based on thrust data and navigation data, the system can isolate and measure disturbance effects independently, resolving the inability to distinguish between the two causes of movement.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The trained model acts as an intermediary that processes both thrust data and navigation data to produce separate estimates of thrust-induced movement and disturbance-induced movement. This intermediary processing layer enables the system to differentiate between the two effects that would otherwise be indistinguishable in the combined position information.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If traditional disturbance estimation methods are used, then control can be performed, but disturbance changes by increments and timely ascertainment is difficult, slowing down navigation efficiency

Engineering Contradiction:

Improvenavigation speedVSAvoidtime to ascertain disturbance

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The system performs preliminary action by continuously estimating disturbance in real-time using the trained model as the ship navigates. Rather than waiting for disturbance to manifest as position errors, the system proactively estimates disturbance based on thrust data and navigation data, enabling timely adjustment of hull control before significant deviations occur.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements continuous feedback by repeatedly estimating disturbance using the trained model and using this information to adjust hull control in real-time. This closed-loop feedback mechanism allows the system to respond promptly to changing disturbance conditions, maintaining accurate navigation without time loss.

Inventive Principle:

Principle #23Feedback

3Measurement precision

If more sophisticated disturbance measurement methods are developed, then disturbance estimation accuracy improves, but device complexity increases

Engineering Contradiction:

Improvedisturbance measurement accuracyVSAvoidcomplexity of disturbance estimation system

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical or physical disturbance measurement systems with a computational approach using a trained model. Instead of adding physical sensors or mechanical devices to directly measure disturbance, the system uses software-based machine learning to estimate disturbance from existing thrust and navigation data, achieving high measurement precision without proportionally increasing device complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The trained model creates a computational copy or representation of the disturbance effects based on patterns learned from training data. This virtual model allows the system to estimate disturbance accurately without requiring direct physical measurement of every disturbance force, simplifying the overall system while maintaining measurement precision.

Inventive Principle:

Principle #26Copying

Data Source

PatentUS12208869B2Disturbance estimating apparatus, method, and computer program

Publication Date: 2025.01.28 FURUNO ELECTRIC CO LTD

AI summary

A disturbance estimation apparatus including a navigation data receiver, a thrust data receiver, and processing circuitry is provided. The navigation data receiver acquires navigation data including an actual position and time of the ship on a water surface. The thrust data receiver receives thrust data indicating a magnitude and a direction of a thrust force of the ship. The processing circuitry estimates a predicted position of the ship at a future point in time and a predicted arrival time of the ship to reach the predicted position by inputting the navigation data and the thrust data into a first trained model, and determines disturbance data including a drift direction and drift speed of the ship drifted by an external force based on a difference between the predicted position estimated by the first trained model and the actual position of the ship at the predicted arrival time.