Bond Graph & FCM Comparison User Guide — Nomenclature and Introduction

Version: 3.9.1

1 Nomenclature

Term	Definition
FCM	Fuzzy Cognitive Maps
FMEA	Failure Modes and Effects Analysis
FMECA	Failure Modes, Effects and Criticality Analysis
FTA	Fault Tree Analysis
HWIL	Hardware-in-the-loop
MADE	Maintenance Aware Design Ecosystem
RAM	Reliability, Availability & Maintainability

2 Introduction

Modeling approaches in MADE require an understanding of the physical laws and relations which govern the behavior of various elements of a system, including the interactions between these elements and a knowledge of the system structure.

With these considerations, MADE utilizes FCM and Bond graph simulations as a basis for:

• Developing a functional model of a system
• Configuring the system model (simplification, combination of items)
• Defining simulation parameter data
• Analyzing or troubleshooting system behavior responses including initial (transient) and final (steady-state) responses of each flow property to all simulated (injected) failure modes
• Verification of test results by comparison with previous simulations

This guide aims at answering the following question:

"When and how should the user create a system model for FCM or Bond graph simulation?"

Firstly, the user should understand how each simulation method works and what its main purpose is (e.g. what system outputs or flows are of interest). If the main purpose of modeling is to represent systems involved in signal or process engineering, the FCM simulation approach is preferred as it maps material, energy or signal flow relationships and potential failures across the system. If the main goal of modeling is to represent power transmission, bond graph modeling is the preferred approach as it investigates the instant (dynamic) power flows taking place between the items in a modeled system.

"Bond graph modeling is the preferred approach for modeling power transmission systems while FCM modeling is used to represent functional relationships for systems providing a combination of material, signal or energy flows."

Figure 1: Summary of FCM (left) and Bond (right) simulations — a diagram showing:

• FCM inputs: Unidirectional Exchange of Information, Signal/Process Engineering Systems, Engineering Domain Specific → converge into "FCM"
• Bond Graph inputs: Bi-directional Exchange of Information, Power Transmission Systems, Multidisciplinary Engineering Domains → converge into "Bond Graph"