Distributed Simulation Platforms and Data Passing Tools for Natural Hazards Engineering: Reviews, Limitations,and Recommendations

here has been a strong need for simulation environments that are capable of modeling deep interdependencies between complex systems encountered during natural hazards,such as the interactions and coupled effects between civil infrastructure systems response,human behavior,and social policies,for improved community resilience.Coupling such complex components with an integrated simulation requires continuous data exchange between different simulators simulating separate models during the entire simulation process.This can be implemented by means of distributed simulation platforms or data passing tools.In order to provide a systematic reference for simulation tool choice and facilitating the development of compatible distributed simulators for deep interdependent study in the context of natural hazards,this article focuses on generic tools suitable for integration of simulators from different fields but not the platforms that are mainly used in some specific fields.With this aim,the article provides a comprehensive review of the most commonly used generic distributed simulation platforms(Distributed Interactive Simulation(DIS),High Level Architecture(HLA),Test and Training Enabling Architecture(TENA),and Distributed Data Services(DDS))and data passing tools(Robot Operation System(ROS)and Lightweight Communication and Marshalling(LCM))and compares their advantages and disadvantages.Three specific limitations in existing platforms are identified from the perspective of natural hazard simulation.For mitigating the identified limitations,two platform design recommendations are provided,namely message exchange wrappers and hybrid communication,to help improve data passing capabilities in existing solutions and provide some guidance for the design of a new domain-specific distributed simulation framework.

X-In-the-Loop Methodology and Simulation Platform For Controller Development of Gravity-1

The Gravity-1(YL-1) launch vehicle has been extensively optimized in terms of its overall layout which in turn has increased the functional and performance demands on the control system. To thoroughly validate and verify the control system, the X-In-the-Loop simulation methodology was implemented from the verification of the YL-1's concept phase. Throughout the entire development cycle, from the initial concept demonstration to the flight test,simulations under sevral modes including Model-in-the-Loop(MiL), Software-in-the-Loop(SiL) and Hardware-in-theLoop(HiL) were executed following the V-V process which ensuring the correctness and robustness of the control system. Specifically, MiL simulation are primarily used to verify the accuracy and robustness of the control strategies and parameters. SiL simulation focused on verifying the correctness of the code implementation. Whereas HiL testing mainly checked the operational correctness of the flight control hardware, the compatibility of flight control software within the flight control computer and the correctness of hardware I/O. In addition to these, further semi-physical simulations were possible on the HiL platform by replacing models of controlled objects with real devices such as IMUs and TVC actuators. And realistic flight conditions were replicated through turntables, TVC actuator loading tables etc.to achieve a more comprehensive validation and verification of the control system.

Digital Simulation Platform for Satellite Launch Mission Verification

To simulate the satellite launch mission under a general platform which could be used in a full-digital mode as well as in a semi-physical way, is an important way to certify the mission design performance as well as technical feasibilities, and it relates to complex system simulation methods such as multi-disciplinary coupling, multi-language modeling as well as interactive simulation and virtual simulation technologies. This paper introduces the design of a digital simulation platform for satellite launch mission verification.The platform has the advantages of high generality and extensibility, being easy to build up. The Functional Mockup Interface(FMI) Standard is adopted to achieve integration of multi-source models. A WebGL based 3D visual simulation tool is also adopted to implement the virtual display system which could display the rocket launch process and rocket-satellite separation with high fidelity 3D virtual scenes. A configuration tool was developed to map the 3D objects in the visual scene with simulation physical variables for complex rocket flight control mechanisms, which greatly improves the platform's generality and extensibility. Finally the real-time performance had been tested and the YL-1 launch mission was adopted to demonstrate the functions of the platform.The platform will be used to construct a digital twin system for satellite launch missions in the future.

SPACECRAFT DOCKING SIMULATION USING HARDWARE-IN-THE-LOOP SIMULATOR WITH STEWART PLATFORM

A ground-based hardware-in-the-loop （HIL） simulation system with hydraulically driven Stewart platform for spacecraft docking simulation is presented. The system is used for simulating docking process of the on-orbit spacecraft. Principle and structure of the six-degree-of-freedom simulation system are introduced. The docking process dynamic of the vehicles is modeled. Experiment results and mathematical simulation data are compared to validating the simulation system. The comparisons of the results prove that the simulation system proposed can effectively simulate the on-orbit docking process of the spacecraft.

Model architecture-oriented combat system effectiveness simulation based on MDE

Combat system effectiveness simulation (CSES) is a special type of complex system simulation. Three non-functional requirements (NFRs), i.e. model composability, domain specific modeling, and model evolvability, are gaining higher priority from CSES users when evaluating different modeling methodologies for CSES. Traditional CSES modeling methodologies are either domain-neutral (lack of domain characteristics consideration and limited support for model composability) or domain-oriented (lack of openness and evolvability) and fall short of the three NFRs. Inspired by the concept of architecture in systems engineering and software engineering fields, we extend it into a concept of model architecture for complex simulation systems, and propose a model architecture-oriented modeling methodology in which the model architecture plays a central role in achieving the three NFRs. Various model-driven engineering (MDE) approaches and technologies, including simulation modeling platform (SMP), unified modeling language (UML), domain specific modeling (DSM), eclipse modeling framework (EMF), graphical modeling framework (GMF), and so forth, are applied where possible in representing the CSES model architecture and its components' behaviors from physical and cognitive domain aspects. A prototype CSES system, called weapon effectiveness simulation system (WESS), and a non-trivial air-combat simulation example are presented to demonstrate the methodology.

A Study of Virtual Museum Simulation Platform Based on 2.5D Architectural Modeling Technology

With the application of virtual reality technology to realize interactive display of virtual museum as content of study,we analyze the problems in the current virtual museum system.Taking Daqing Museum for example,we develop a 2.5D(between 2D and 3D) architectural modeling technology,and combine it with virtual reality technology,to create the virtual museum simulation platform.By establishing the virtual simulation platform of Daqing Museum,we verify the feasibility of using 2.5D architectural modeling technology to build the virtual museum system,create a virtual simulation platform with practical value,and show the bright future of virtual museum based on 2.5D virtual reality technology.

Methods for the Construction and Realization of a Humanoid Robot's Simulation Platform

This paper proposes a method of humanoid robot data structure definition based on the characteristics of a graph with tree structure. It applies the depth-first search algorithm to traverse and uses screw theory and chain of multiplication to describe the robot＇s postures. The platform references zero moment point theory as the stability constraint of the robot＇s dynamic walking and plans the gaits accordingly, h also realizes the visualization of motion control. This study provides superior means and methods to the evolution of a humanoid robot.

Dynamic Characteristics of Tracked Vehicle Power Train Considering Road Random Torsional Excitation

The road random torsional excitation is one type of torque rooted from the road roughness and vehicle drive system. This paper aims to study how the road random torsional excitation affects the dynamic characteristics of vehicle power train. The method of simulating the random torsional excitation of tracked vehicle is explored at first. Secondly,the road random torsional excitations under different road roughness,vehicle speeds and pre-tensions are obtained. Thirdly,the dynamic analysis model of tracked vehicle power train is constructed with the consideration of the road random torsional excitation. Eventually,the influences of this excitation on output torque,bearing support force,vibration acceleration and dynamic shear stress of transmission shafts are intensively studied.The research conclusions are helpful to correct and refine the present virtual prototype of tracked vehicle power train.

A Novel Approach to the Convergence Proof of Ant Colony Algorithm and Its MATLAB GUI-Based Realization

Although ant colony algorithm for the heuristic solution of hard combinational optimization problems enjoy a rapidly growing popularity, but little is known about its convergence properties. Based on the introduction of the basic principle and mathematical model, a novel approach to the convergence proof that applies directly to the ant colony algorithm is proposed in this paper. Then, a MATLAB GUI- based ant colony algorithm simulation platform is developed, and the interface of this simulation platform is very friendly, easy to use and to modify.

Digital/Analog Simulation Platform for Distributed Power Flow Controller Based on ADPSS and dSPACE

Distributed power flow controller,which is among the most powerful distributed flexible transmission equipments,is still only in the stage of the oretical research and digital simulation.In order to promote the engineering demonstration of a distributed power flow controller,it is urgent to establish a digital/analog simulation platform that supports closed-loop real-time simulation of a distributed power flow controller.In this paper,the electromagnetic transient model of a distributed power flow controller is established on ADPSS(advanced digital power system simulator).The rapid control prototype realized by dSPACE is connected to ADPSS to form a digital/analog simulation platform for a distributed power flow controller.Through a voltage control and power flow control simulation of the test system with a distributed power flow controller,the correctness and effectiveness of the constructed simulation platform are verified,which provides a new way for the verification of the new theory of a distributed power flow controller.

Agent-based simulation platform for cloud manufacturing

Cloud manufacturing is a new manufacturing paradigm which creates an open environment for transactions among the enterprises.Research on transaction modes and regularities in a cloud manufacturing environment is important for promoting the applications of cloud manufacturing.To this end,we design and implement a simulation platform according to the typical transaction processes of enterprises in the cloud manufacturing environment.In the simulation platform,enterprises are encapsulated into Service Agents,and thus the activities of service agents can be used to describe enterprise behaviors.By defining different rules,simulations for different business models can be conducted.Detailed descriptions of the platform architecture,functions,and key technologies are presented.The feasibility of the simulation platform is verified through a case study.

Research on system architecture of modeling and simulation

The modeling and simulation(M&S)architecture describes and defines the relationship between the different parts of a simulation.The simulation system architecture and simulation support platform architecture are discussed separately.The simulation support platform architecture consists of the management layer,the resource layer,the communication layer,the application layer and the infrastructure layer.The best way is to design and realize the M&S collaborative environment for simulation support platform in the resource-communication-application three-dimension space.

Digital twins in smart farming:An autoware-based simulator for autonomous agricultural vehicles

Digital twins can improve the level of control over physical entities and help manage complex systems by integrating a range of technologies.The autonomous agricultural machine has shown revolutionary effects on labor reduction and utilization rate in field works.Autonomous vehicles in precision agriculture have the potential to improve competitiveness compared to current crop production methods and have become a research hotspot.However,the development time and resources required in experiments have limited the research in this area.Simulation tools in unmanned farming that are required to enable more efficient,reliable,and safe autonomy are increasingly demanding.Inspired by the recent development of an open-source virtual simulation platform,this study proposed an autoware-based simulator to evaluate the performance of agricultural machine guidance based on digital twins.Oblique photogrammetry using drones is used to construct threedimensional maps of fields at the same scale as reality.A communication format suitable for agricultural machines was developed for data input and output,along with an inter-node communication methodology.The conversion,publishing,and maintenance of multiple coordinate systems were completed based on ROS(Robot Operating System).Coverage path planning was performed using hybrid curves based on Bézier curves,and it was tested in both a simulation environment and actual fields with the aid of Pure Pursuit algorithms and PID controllers.

The research of traffic density extraction method under vehicular ad hoc network environment

Purpose–Traffic density is one of the most important parameters to consider in the traffic operationfield.Owing to limited data sources,traditional methods cannot extract traffic density directly.In the vehicular ad hoc network(VANET)environment,the vehicle-to-vehicle(V2V)and vehicle-to-infrastructure(V2I)interaction technologies create better conditions for collecting the whole time-space and refined traffic data,which provides a new approach to solving this problem.Design/methodology/approach–On that basis,a real-time traffic density extraction method has been proposed,including lane density,segment density and network density.Meanwhile,using SUMO and OMNet11 as traffic simulator and network simulator,respectively,the Veins framework as middleware and the two-way coupling VANET simulation platform was constructed.Findings–Based on the simulation platform,a simulated intersection in Shanghai was developed to investigate the adaptability of the model.Originality/value–Most research studies use separate simulation methods,importing trace data obtained by using from the simulation software to the communication simulation software.In this paper,the tight coupling simulation method is applied.Using real-time data and history data,the research focuses on the establishment and validation of the traffic density extraction model.