Simulation Bridge (sim-bridge) is a modular, reusable, and bidirectional middleware designed to orchestrate distributed simulation systems involving Digital Twins (DTs), Mock Physical Twins (MockPTs), and Physical Twins (PTs).
It acts as an intelligent communication layer between DTs, PTs, and heterogeneous simulation environments, integrating and coordinating simulations developed with diverse models, technologies, and protocols.
sim-bridge exposes a unified interface that enables seamless data exchange and interaction. It receives inputs from DTs or PTs, routes them to the appropriate simulators through dedicated components called Simulator Agents, collects the simulation results, and delivers them back to the clients.
Figure 1: Simulation Bridge Architecture
Please refer to the User Guide for detailed requirements, configuration instructions, and usage guidelines for the Simulation Bridge.
Agent is a software connector that acts as an interpreter between sim-bridge and the specific simulator. Each simulator requires its own Agent, which must be designed to be reusable across diverse simulation scenarios for that simulator.
Refer to the Matlab Agent for an implementation example.
sim-bridge supports Batch and Streaming simulation modes, allowing for both discrete and real-time streaming simulation workflows:
| Mode | Description |
|---|---|
| Batch | Inputs are provided at the start, the simulation runs to completion without intermediate monitoring, and results are delivered only at the end. |
| Streaming | Enables real-time, step-by-step updates from the simulation during execution |
The system follows a plug-in-based protocol adapter architecture, enabling seamless future integration of additional protocols. It currently supports MQTT, RabbitMQ, and RESTful interfaces, allowing external clients to communicate with the sim-bridge through these channels.
Supports secure (TLS) and insecure connections for all protocols: MQTT/mqtts, AMQP/amqps, HTTP/2.0, and HTTPS.
TLS certificates (cert.pem, key.pem) are generated automatically when needed.
Figure 2: Plug-in Protocol Adapter Architecture
- User Guide ↗: Comprehensive guide covering system requirements, configuration steps, and detailed usage instructions for the Simulation Bridge.
- Internal Architecture ↗: Overview of the system's architecture, key modules, and their interactions.
- Class Diagram ↗: UML Class Diagram of the Simulation Bridge Architecture
- In-Memory Adapter ↗: Using the bridge directly from Python
- Performance Metrics ↗: Overview of the performance metrics generated by the Simulation Bridge
- Performance Analysis ↗: Command-line tool for quantifying the overhead introduced by the Simulation Bridge, analyzing the performance metrics.
- Matlab Agent ↗: Explanation of the MATLAB agent functionality and configuration.
- Matlab Simulation Constraints ↗: A breakdown of the constraints and requirements for MATLAB-driven simulations.
The developer-specific commands are
pylint simulation_bridge
autopep8 --in-place --aggressive --recursive 'simulation_bridge'
pytest --cov=simulation_bridge --cov-report=term --cov-report=html simulation_bridge/test/
open htmlcov/index.htmlThis project is licensed under the INTO-CPS Association Public License v1.0.
See the LICENSE file for full license text.
