Development of a Mathematical Model for Harbor-Maneuvers to Realize Modeling Automation

TL;DR

This paper introduces a hybrid dynamic model for harbor maneuvers that simplifies model derivation and enables automatic model generation, reducing human effort and dependency on hydrodynamic expertise.

Contribution

A novel hybrid modeling approach combined with system identification allows automatic generation and selection of harbor maneuver models, streamlining the process and reducing manual intervention.

Findings

Model shows equivalent or better estimation performance than traditional methods.

Enables automatic model generation reducing human decision-making.

Validated with free-running model tests.

Abstract

A simulation environment of harbor maneuvers is critical for developing automatic berthing. Dynamic models are widely used to estimate harbor maneuvers. However, human decision-making and data analysis are necessary to derive, select, and identify the model because each actuator configuration needs an inherent mathematical expression. We proposed a new dynamic model for arbitrary configurations to overcome that issue. The new model is a hybrid model that combines the simplicity of the derivation of the Taylor expansion and the high degree of freedom of the MMG low-speed maneuvering model. We also developed a method to select mathematical expressions for the proposed model using system identification. Because the proposed model can easily derive mathematical expressions, we can generate multiple models simultaneously and choose the best one. This method can reduce the workload of model identification and selection. Furthermore, the proposed method will enable the automatic generation of dynamic models because it can reduce human decision-making and data analysis for the model generation due to its less dependency on the knowledge of ship hydrodynamics and captive model test. The proposed method was validated with free-running model tests and showed equivalent or better estimation performance than the conventional model generation method.