Real-time Simulation Technology Research Articles

Real-Time Wave Simulation of Large-Scale Open Sea Based on Self-Adaptive Filtering and Screen Space Level of Detail

The real-time simulation technology of large-scale open sea surfaces has been of great importance in fields such as computer graphics, ocean engineering, and national security. However, existing technologies typically have performance requirements or platform limitations, and the two are often impossible to balance. Based on the camera-view-based screen space level of detail strategy and virtual camera pose adaptive filtering strategy proposed in this article, we have developed a fast and comprehensive solution for rendering large-scale open sea surfaces. This solution is designed to work without the need for special hardware extensions, making it easy to deploy across various platforms. Additionally, it enhances the degrees of freedom of virtual camera movement. After conducting performance tests under various camera poses, our filtering strategy was found to be effective. Notably, the time cost of simulation using 60 waves at the height of 6 m above sea level was only 0.184 ms. In addition, we conducted comparative experiments with four state-of-the-art algorithms currently in use, and our solution outperformed the others with the best performance and suboptimal visual effects. These results demonstrate the superiority of our approach in terms of both efficiency and effectiveness.

Research on digital twin technology of large-scale offshore wind power flexible direct transmission system

With the rapid development of wind power technology, offshore wind power transmission technology has gradually matured. Combined with the first large-scale offshore wind power flexible DC transmission system in China, this paper builds a digital twin system that is close to the actual system. The article first introduces the origin and definition of digital win technology and gives the five-dimensional model of the digital twin. Then, it focuses on the technical realization of the offshore wind power digital twin system, including the five-dimensional model of the offshore wind power digital twin system. The key technologies in the advanced application of the twin system - real-time simulation technology and 3D holographic visual display technology are introduced, and their effects are shown. The realization of the digital twin technology of the large-scale offshore wind power flexible DC transmission system provides more valuable information for the operation, management, scheduling, and decision-making of the offshore wind power flexible direct transmission system.

Design Method of Laboratory-Scale MMC Physical Simulation System Considering Multiharmonic Simulation Accuracy

Besides real-time numerical simulation technology, the laboratory-scale physical simulation technology is an alternative for simulation analysis and hardware testing of modular multilevel converter (MMC). It can realize full-scale connection with complicated control and protection hardware with no need for extra interface devices, which is necessary in real-time simulation. However, due to the limitations on size and investment, the power loss rate of the MMC physical simulation system is inevitably higher than that of the real MMC project, which obviously will have a negative effect on the simulation accuracy. To solve the problem, an improved parameter design method of the MMC physical simulation system is proposed in this article. The similarity criteria of MMC with explicit expressions are first derived. On this basis, the relationship between multiharmonic simulation accuracy and power loss nonsimilarity is theoretically analyzed. Furthermore, the range of the power loss nonsimilarity is determined, which facilitates the selections of passive elements in the MMC physical simulation system with appropriate quality factors. The proposed design method can guarantee the simulation accuracy while reducing the whole system investment. Finally, the effectiveness of the proposed design method is validated by both the simulation and experimental results.

Real-Time Power Electronics Laboratory to Strengthen Distance Learning Engineering Education on Smart Grids and Microgrids

In the science and engineering fields of study, a hands-on learning experience is as crucial a part of the learning process for the student as the theoretical aspect of a given subject. With the COVID-19 pandemic in 2020, educational institutions were forced to migrate to digital platforms to ensure the continuity of the imparted lectures. The online approach can be challenging for engineering programs, especially in courses that employ practical laboratory methods as the primary teaching strategies. Laboratory courses that include specialized hardware and software cannot migrate to a virtual environment without compromising the advantages that a hands-on method provides to the engineering student. This work assesses different approaches in the virtualization process of a laboratory facility, diving these into key factors such as required communication infrastructure and available technologies; it opens a discussion on the trends and possible obstacles in the virtualization of a Real-Time (RT) laboratory intended for Microgrid education in a power electronics laboratory course, exposing the main simulation strategies that can be used in an RT environment and how these have different effects on the learning process of student, as well as addressing the main competencies an engineering student can strengthen through interaction with RT simulation technologies.

-Practice before Practicum: Simulation in Initial Teacher Education

The benefits of micro-teaching (pre-service teachers practicing their teaching skills with small groups of peers or students) are well documented. However, the overcrowding of the teacher education curriculum, in part due to regulatory mandates, led many initial teacher education (ITE) programs to abandon using micro-teaching. The focus of this study was to understand the experiences of pre-service teachers who are engaging in real-time simulation technology as a new form of micro-teaching. The analysis of our findings indicated that the use of the mixed-reality learning environments (MRLEs) showed promise in helping build candidate self-confidence and preparing novices for their first “real” teaching practicum. MRLEs appear to be particularly useful for assisting with developing confidence, planning for diverse learners, understanding personalizing pedagogy and engaging with classroom management. We argue the importance of micro-teaching “2.0” as a strategy to “practice before prac” and call for increased inclusion of simulation within ITE programs.

Evaluating dynamic visual experience of designed environments: A real-time 3D simulation method utilizing game technologies

Dynamic vision refers to a person’s visual perception of the environment when the person is in motion. Pedestrians naturally have dynamic visual experiences, the aesthetic qualities of which may modify their walking and seeing behaviors. Despite the subject’s significant design relevance, dynamic visual research has shown limited theoretical and methodological progress since the 1960s. Inspired by recent development in 3D visibility research, this paper proposes a Real-Time Dynamic Visual Evaluation (RtDVE) protocol that simulates and evaluates pedestrians’ dynamic visual experiences in designed environments. The protocol utilizes Downtown Explorer, a 3D game developed to allow research participants to simulate free-roaming walks by controlling a pedestrian avatar. The game synchronously collects graphic and numerical data about the avatar’s first-person sequential views. The RtDVE protocol prescribes computational procedures to convert collected data into diagrammatic charts illustrating view-to-view transitions within the avatar’s Field of View. The protocol also introduces Dynamic Visual Variance Index, a composite quantitative index synthesizing multiple numerical data to facilitate comparisons of dynamic visual experiences across various simulated walks. Through a two-stage empirical study, the paper reveals the RtDVE protocol’s conception and demonstrates its effectiveness. The study applied the RtDVE protocol to investigate simulated dynamic visual experiences about different architectural massing schemes. The descriptive analysis outcomes facilitated the exploratory evaluation of these design schemes’ implications on pedestrians’ dynamic vision. Given its strengths in operability and research quality, the RtDVE protocol can promote evidence-based, user-centered design practices incorporating dynamic visual evaluation. Future RtDVE studies may adopt evolved real-time 3D simulation technologies and more sophisticated research designs to examine the complex ecological interplay between the objective and subjective factors in dynamic vision.

Real-time hardware emulation of wind turbine model with asynchronous generator under hardware-in-the-loop platform

Abstract Renewable energy sources are becoming as one of the major generation strategies around the world. The wind energy systems have been technologically advanced and integrated to the power system in a rapid routine. This paper looks into the modelling as well as operational exploration of a three blade wind turbine connected to asynchronous generator. State-of-the-art wind turbine topologies and a comparative summary of real-time simulation technologies for electrical systems are described. A 2.4 MW wind turbine with three blades is modelled for the analysis of power characteristics. The shift from sub-synchronous to super-synchronous mode is analysed for type-A wind energy conversion system (WECS) with 2 MW asynchronous generator by using MATLAB/Simulink model. The step-by-step standard operating procedure for modelling and real-time simulation of 2 MW type-A WECS having asynchronous generator under hardware-in-the-loop platform is elucidated. The steady state and transient behaviours of the WECS are validated by the real-time emulation under a hardware-in-the-loop platform.

Design and implementation of a virtual ARINC 653 simulation platform

The ARINC 653 operation system is currently widely adopted in the avionics industry, and has become the mainstream architecture in avionics applications because of its strong agility and reliability. Although ARINC 653 can efficiently reduce the weight and energy consumption, it results in a serious development and verification problem for avionics systems. As ARINC 653 is non-open source software and lacks effective support for software testing and debugging, it is of great significance to build a real-time simulation platform for ARINC 653 on general-purpose operating systems, improving the efficiency and effectiveness of system development and implementation. In this paper, a virtual ARINC 653 platform is designed and realized by using real-time simulation technology. The proposed platform is composed of partition management, communication management, and health monitoring management, provides the same operation interfaces as the ARINC 653 system, and allows dynamic debugging of avionics applications without requiring the actual presence of real devices. Experimental results show that the platform not only simulates the functionalities of ARINC 653, but also meets the real-time requirements of avionics applications.

Lab-scale Models of Manufacturing Systems for Testing Real-time Simulation and Production Control Technologies

In the last years, the increase of data availability together with enhanced computation capabilities empowered researchers to conceive production planning and control methods with real-time inputs. Literature is rich with techniques for using simulation to take production planning and control decisions online. However, it is generally impractical to test these approaches on real systems, and experiments on digital instances are limited because they do not capture the physical aspects. This work proposes to test Real-time Simulation approaches using lab-scale models of manufacturing systems and a software architecture aligned with industrial standards. Such models allow to reproduce material flows and the production control logic of real factory environments. By exploiting this setting to test new approaches and tools, it is possible to increase their own achievable Technology Readiness Level (TRL). The laboratory has been used to set a real-time rescheduling problem on a Flexible Manufacturing System (FMS) model. The test involves simulation models aligned with the current system state for the online identification and implementation of a production scheduling rule that decreases the expected makespan. The results testify that the proposed lab-scale models can be used successfully to test production planning and control approaches.

Advanced Laboratory Testing Methods Using Real-Time Simulation and Hardware-in-the-Loop Techniques: A Survey of Smart Grid International Research Facility Network Activities

The integration of smart grid technologies in interconnected power system networks presents multiple challenges for the power industry and the scientific community. To address these challenges, researchers are creating new methods for the validation of: control, interoperability, reliability of Internet of Things systems, distributed energy resources, modern power equipment for applications covering power system stability, operation, control, and cybersecurity. Novel methods for laboratory testing of electrical power systems incorporate novel simulation techniques spanning real-time simulation, Power Hardware-in-the-Loop, Controller Hardware-in-the-Loop, Power System-in-the-Loop, and co-simulation technologies. These methods directly support the acceleration of electrical systems and power electronics component research by validating technological solutions in high-fidelity environments. In this paper, members of the Survey of Smart Grid International Research Facility Network task on Advanced Laboratory Testing Methods present a review of methods, test procedures, studies, and experiences employing advanced laboratory techniques for validation of range of research and development prototypes and novel power system solutions.

633-P: Impact of Simulation-Based CME on Clinicians’ Knowledge and Competence Related to Hypoglycemia Management

We sought to determine if real-time patient simulation technology, designed to mimic a patient visit, could improve clinicians’ knowledge/competence regarding the management of hypoglycemia in patients with type 2 diabetes (T2D). The patient simulation technology, DecisionSim, was incorporated as part of a live symposium, and changes in competence and knowledge were evaluated using pre-/post-assessment questions. A Chi-Square test was used to analyze the percentage of correct responses and determine statistical significance (p <0.05 indicated statistical significance). The live activity took place on October 26, 2018. In total, 66 allied health professionals (PAs, RNs, NPs, PharmDs, CDE/RDs) and 41 MDs/DOs answered the assessment questions. An increase in knowledge was observed, albeit not statistically significant (4% relative increase compared to baseline, p = 0.6). A significant increase in competence in selecting the most appropriate treatment to address hypoglycemia risk for a patient with T2D was observed (120% relative increase compared to baseline, p <0.0001). 82% selected the correct treatment decisions in the branching simulation platform, including the intensification of therapy that addresses HbA1c goals while minimizing the risk of hypoglycemia in a virtual patient with T2D. Additionally, 83% indicated in the post-activity survey that they would make changes to practice based on information received, including to provide patient-centered care, assess the current diabetes guidelines, and use diabetes treatments that minimize hypoglycemia. Continued educational gaps were identified: lack of knowledge about the benefits of GLP-1RA/insulin combinations (17%), and lack of competence in individualizing T2D therapy in the context of hypoglycemia risk (21%). These results indicate that simulation-based CME can lead to significant improvements in competence related to hypoglycemia management, as well as commitment to change among learners. Disclosure S. Karandrea: None. N. Agarwal: None. A. Jamrogiewicz: None. Funding Sanofi US (IME-2017-12078)

Airport Rescue and firefighting Way in the 5g era

With the maturity of the fifth generation of mobile communication technology (5G), the new technology associated with 5G will have a great impact on the way of Rescue and firefighting in airports. Based on the development of existing technologies in the 5G era, the personnel in the aircraft Positioning technology, real-time scenario monitoring, measurement and data transmission technology for drones, real-time simulation and prediction technology of the aircraft fire situation, and the combination of remote fire hydrants and unmanned RFF vehicles will greatly improve the efficiency and success rate of fire rescue, and reduce the risk to fire rescue workers.

Analysis and Simulation of Dynamic Vision in the City

This paper proposes a computer-aided Dynamic Visual Research and Design Protocol for environmental designers to analyze humans' dynamic visual experiences in the city and to simulate dynamic vision in the design process. The Protocol recommends using action cameras to collect massive dynamic visual data from participants' first-person perspectives. It prescribes a computer-aided visual analysis approach to produce cinematic charts and storyboards, which further afford qualitative interpretations for aesthetic assessment and discussion. Employing real-time 3D simulation technologies, the Protocol enables the simulation of people's dynamic vision in designed urban environments to support evaluation in design. Detailed contents and merits of the Protocol were demonstrated by its application in the Urbanscape Studio, a community participatory design course based at Watertown, South Dakota.

FPGA-Based Device-Level Electro-Thermal Modeling of Floating Interleaved Boost Converter for Fuel Cell Hardware-in-the-Loop Applications

Floating interleaved boost converter (FIBC) is a promising topology of the dc/dc converters to interface the fuel cell with dc bus in a hybrid powertrain. For the efficient control development of power converters, the hardware-in-the-loop (HIL) simulation plays an important role. The accuracy of the real-time model determines the credibility of the HIL simulation. In order to take the power losses and thermal stress into account in the control development, the device-level real-time model is becoming popular in recent years, which can effectively produce device transient voltage and current waveforms, switching power dissipations, and thermal behaviors. In this paper, a device-level electro-thermal model of FIBC is proposed and developed using the field programmable gate array based real-time simulation technology. The FIBC network model can effectively be simulated with a 500-ns time step while producing the insulated-gate bipolar transistor transient switching waveforms authentically with a 5-ns resolution. The switching power losses can thus be estimated in real time and then used for the computation of the IGBT thermal behavior. Therefore, the device junction temperature can be evaluated in the real-time simulation. The accuracy of the proposed FIBC device-level model is validated by the reference model in the Saber offline simulation tool. At last, an embedded PI controller of FIBC is employed in the real-time experiments to verify the effectiveness of the developed model.

The Application of Hardware-in-the-Loop (HIL) Simulation for Evaluation of Active Safety of Vehicles Equipped with Electronic Stability Control (ESC) Systems

Automated vehicles are one of the most popular trends of modern R&D in the automotive industry. However autonomous driving is impossible without such electronic systems as Anti-Lock Braking System (ABS) and Electronic Stability Control (ESC). Development, adaptation, setup and debugging of mentioned systems require a large amount of field tests. The application of modern real-time simulation technologies based on Hardware-in-the-Loop (HIL) simulation allows to decrease the number of field tests. The paper is dedicated to the development and validation of a HIL test bench for virtual real-time testing of the GAZ Group light commercial vehicles equipped with ESC systems.

Numerical simulation of a cabin ventilation subsystem in a space station oriented real-time system

An environment control and life support system (ECLSS) is an important system in a space station. The ECLSS is a typical complex system, and the real-time simulation technology can help to accelerate its research process by using distributed hardware in a loop simulation system. An implicit fixed time step numerical integration method is recommended for a real-time simulation system with time-varying parameters. However, its computational efficiency is too low to satisfy the real-time data interaction, especially for the complex ECLSS system running on a PC cluster. The instability problem of an explicit method strongly limits its application in the ECLSS real-time simulation although it has a high computational efficiency. This paper proposes an improved numerical simulation method to overcome the instability problem based on the explicit Euler method. A temperature and humidity control subsystem (THCS) is firstly established, and its numerical stability is analyzed by using the eigenvalue estimation theory. Furthermore, an adaptive operator is proposed to avoid the potential instability problem. The stability and accuracy of the proposed method are investigated carefully. Simulation results show that this proposed method can provide a good way for some complex time-variant systems to run their real-time simulation on a PC cluster.

Multivalued Coefficient Prestorage and Block Parallel Method for Real-Time Simulation of Microgrid on FRTDS

The microgrid containing a large amount of high frequency power switches and nonlinear components has put forward high requirements for power system real-time simulation technology. Multivalued coefficient prestorage can reduce the calculation steps in real-time simulation. In order to reduce the storage pressure of the multivalued coefficients, the whole network is divided into multiple subnetworks that can be simulated in parallel, and only the parameters for computing input variables and internal variables are prestored. The multiport hybrid equivalent is performed to reduce the number of simultaneous network equations. The input variables are tied to state variables of the circuit so that the iterative calculation is limited to the local network. The devised methodology is validated through simulation of a low-voltage microgrid on a field programmable gate array (FPGA)-based real-time digital simulation (FRTDS) platform at a 5 μs time step. Comparison with a power systems computer aided design (PSCAD)/electromagnetic transients including DC (EMTDC) model shows that the proposed method is effective.

Overview of Real-Time Simulation as a Supporting Effort to Smart-Grid Attainment

The smart-grid approach undergoes many difficulties regarding the strategy that will enable its actual implementation. In this paper, an overview of real-time simulation technologies and their applicability to the smart-grid approach are presented as enabling steps toward the smart-grid’s actual implementation. The objective of this work is to contribute with an introductory text for interested readers of real-time systems in the context of modern electric needs and trends. In addition, a comprehensive review of current applications of real-time simulation in electric systems is provided, together with the basis to understand real-time simulation and the topologies and hardware used to implement it. Furthermore, an overview of the evolution of real-time simulators in the industrial and academic background and its current challenges are introduced.

Numerical simulations of environment control and life support system in space station-oriented real-time system

An environment control and life support system (ECLSS) is an important system in a space station because it can provide a basic living environment for astronauts. The ECLSS is a typical time-variant complex system, hence there exits time-consuming technical difficulty during its development. The real-time simulation technology can help to accelerate its research process because some models of complex hardware need not to be built and calibrated at all. For a real-time simulation system with time-varying parameters, an implicit fixed time step numerical integration method is normally used as its solver. However, its computational efficiency is too low especially for the complex ECLSS simulation system on a single personal computer (PC) cluster. An explicit fixed time step integration method is computationally efficient, but their potential instability problems, which are caused by the time-varying parameters, limit its application to the ECLSS system. In this paper, an improved model method based on the explicit Euler method is proposed to simulate the complex time-variant ECLSS on a PC cluster. A simplified ECLSS system is established as an example to explain this proposed method. The eigenvalue estimation theory is used to analyze the numerical stability of the simplified system. Further, the potential instability problem of the explicit method can be avoided by an adaptive operator. Both of the stability and the accuracy of the proposed method are investigated carefully. It can be concluded from simulation results that this proposed method can provide a solution to realize the real-time simulation for the complex time-variant ECLSS on a PC cluster.

Fast and Robust Maximum Power Point Tracking for Solar Photovoltaic Systems

Solar Photovoltaic (PV) energy is becoming an increasingly important part of the world's renewable energy. In order to develop technology for efficient energy conversion from a solar PV system, this paper studies typical Maximum Power Point Tracking (MPPT) control techniques used in solar PV industry and then proposes a close-loop and adaptive MPPT method for reliable and rapid extraction of solar PV power. The paper emphasizes especially on how the proposed and conventional adaptive MPPT methods perform under highly variable weather and solar irradiation conditions in a digital control environment. A computer simulation system is developed by using SimPowerSystems and Opal-RT real-time simulation technology which allows for fast and efficient investigations of the MPPT algorithms under high switching frequency conditions for power converters. A hardware experiment system is built to validate and compare the proposed and conventional MPPT techniques in a more practical condition. Advantages, disadvantages and properties of different MPPT methods are compared and studied, evaluated.