Developed Simulation Environment Research Articles

Constellation and data link design for a nano-satellite Earth observation system

A constellation of nano-satellites in low Earth orbits can provide complementary Earth observation (EO) data to current large satellite systems in a cost-efficient way. It increases coverage and reduces revisit time compared to current EO systems with few large satellites. We combine constellation and link simulation tools to study the design trade-offs for a constellation of EO nano-satellites at sun-synchronous orbits (SSOs), carrying a hyperspectral camera over continental Europe. Coverage, revisit time, satellite throughput, and scheduling effects are studied for several sets of parameters. We show that 22 satellites evenly distributed on a plane on an SSO at 499.8 km altitude, with a repeat cycle of 5 days, can provide 100 % of accumulated coverage in 27 hours while collecting data only during the daytime. Data download requires scheduling at ground stations (GSs) when a GS has just one antenna and several satellites are in sight. A GS located after the data collection zone reduces the age of information but requires on-board data storage. The developed simulation environment can be used to design and study new constellations in terms of coverage, revisit time, downlink throughput, and age of information.

Integrated nonlinear structural simulation of composite buildings in fire

The collapse of several tall composite buildings over the last two decades has shown that the performance of tall, composite and complex buildings in fire is a necessary design consideration that ought to go beyond simple code compliance. To this end, several advancements in the field of numerical simulation of both the fire and the thermomechanical response of structures have been made. In isolation, the practical benefit of these advancements is limited, and their true potential is only unlocked when the results of those numerical simulations are integrated. This paper starts by showcasing recent developments in the thermal and thermomechanical analysis of structures using OpenSees. Integration of these developments into a unified simulation environment combining fire simulation, heat transfer, and mechanical analysis is then introduced. Finally, a demonstration example based on the large compartment Cardington test is used to showcase the necessity and efficiency of the developed simulation environment for thermomechanical simulation of composite structures in fire.

REVENUE POTENTIAL OF DIFFERENT PROSUMER TYPES AT LOCAL FLEXIBILITY MARKETS

The actual change in the electricity system due to rising share of decentralized energy resources and new controllable loads such as heat pumps or charging stations for electrical vehicles lead to new challenges in the distribution grid. In a few hours per year, the results are high load and feed-in peaks, which can lead to local critical grid states in medium and low voltage grids. These critical grid states can be prevented with the help of local flexibility markets. Flexible grid users such as prosumers can offer their flexibility and avoid critical grid states. The price of the offered flexibility decides whether the local flexibility market is an economical solution for the congestion management of the distribution system operator. Several factors, such as grid user behaviour or existing marketing strategies, are important when preparing offers and influence the offered prices. One focus is the analysis of the different behaviour of grid users and the classification of grid user types in order to assess how minimum offers at local flexibility market could look like. Based on a developed simulation environment, the trading and pricing on the local flexibility market can be examined in different future scenarios.

Movement of a group of unmanned aerial vehicles in formation

This paper presents a method for organising the movement of unmanned aerial vehicles in formation. In the presented method of UAV collisions are prevented by a modification of the potential field method. The movement of the group is accomplished by incrementing the origin coordinates of the formation at each iteration of data exchange between UAVs. This paper presents a graph showing the negligible positioning error of drones in formation over time as the heterogeneous swarm of quadcopters moves towards the target position. Simulation results show that the flight time of a group of UAVs to the target swarm position using the proposed method is longer than using the master-slave method. The model of a Wi-Fi network as an information exchange network between UAVs was used in the developed simulation environment. This approach facilitates the implementation of the presented method on real aircrafts.

An Approach to Scene Recognition Based on the Local Interaction of a Group of Robots

The paper considers a group of animates (bio-inspired abstract models or technical devices) that use the visual analyzer described by the authors earlier. The visual analyzer recognizes the scene observed by the animat, determines the class of the situation and selects the corresponding behavior. The analyzer is based on the" language of poses" , borrowed from some species of ants, which allows them to visually inform other individuals of their condition. The first proposed algorithm describes a visual memory mechanism that allows an animat to remember seen objects for some time and select its behavior in a more stable way compared to a basic visual analyzer. The second algorithm describes a group recognition approach. Robots are able to exchange information about the scene they are observing presented in the form of a graph using local communication. The robot, receiving such information from its neighbors, is able to expand its picture of the world and more correctly choose its behavior based on the recognized situation than if it only had its own data. A demonstration task was set to test the efficiency, approximately simulating a colony of ants that gather food in a certain area. Colony, nest, food, and enemy individuals are modeled in the developed simulation environment. Group efficiency was defined as the amount of food collected over the allotted time period. Animates using the visual memory algorithm showed an increase in efficiency for all the studied memory parameters. Moreover, the dependence is not monotonic, and there is a certain value at which maximum efficiency is achieved. The use of the group recognition algorithm also showed an increase in efficiency compared to the basic visual analyzer. The experiments were carried out for different distances of local interaction. As with memory, there is a value of interaction distance at which the maximum efficiency is achieved. The combination of both algorithms also has interesting results. The experiments showed that the smaller the memory of the robot, the greater the increase in efficiency from using the collective recognition algorithm.

Micromouse 3D simulator with dynamics capability: a Unity environment approach

The micromouse competition has been gaining prominence in the robotic atmosphere, due to the challenging and multidisciplinary characteristics provided by the teams’ duels, being a gateway for those who intend to deepen their studies in autonomous robotics. In this context, this paper presents a realistic micromouse simulator developed with Unity software, a widely game engine with dynamics and 3D development platform used. The developed simulator has hardware-in-the-loop capabilities, aims to be simple to use, it can be customizable, and designed to be as similar as possible to the real robot configurations. In this way, the proposed simulator requires few modifications to port the microcontroller code to a real robot. Therefore, the framework presented in this work allows the user to simulate the development of new algorithm strategies dedicated to competition and also hardware updates. The simulation supports several mazes, from previous competitions and has the possibility to add different mazes elaborated by the user. Thus, the features and functionality of the simulator can serve to accelerate the project’s development of the beginning and advanced competitors, using real models to reduce the gap between the mouse robot behavior in the simulation and the reality. The developed simulation environment is available to the community.

Closed-loop platoon simulation with cooperative intelligent transportation systems based on vehicle-to-X communication

The continuous enhancement of X-in-the-Loop (XiL) simulation methods is one key to efficiently test advanced vehicle control functions and ensure high software quality under a rising cost and time pressure. Systems, which control vehicles based on sensor perception can already be evaluated in XiL simulations. However, future vehicles will not exclusively represent stand-alone systems anymore, but involve Cooperative Intelligent Transport Systems (C-ITS), distributed among different traffic participants. While several simulation environments for C-ITS feasibility studies are available, common virtual test frameworks cannot incorporate multiple interacting and communicating road users with the required fidelity to secure C-ITS software, e.g. for platooning applications.Within the scope of this publication, a method for virtual testing and calibration of in-vehicle C-ITS using a high fidelity vehicle platoon model is presented. Multiple closed-loop controlled vehicles and the mutual interferences between them are simulated in a common 3D environment alongside other traffic. Each high fidelity vehicle model individually simulates the longitudinal and lateral response, the generation of sensor data plus the exchange of vehicle-to-vehicle data. As a proof of concept, a model-in-the-loop simulation for a Cooperative Adaptive Cruise Control (CACC) was conducted. The simulation environment included five high fidelity vehicle models forming a platoon, coupled with CACC controller models under test.The results reveal that the developed simulation environment captures the interaction within collaborative vehicle groups while modeling individual vehicles as controlled systems in the same tool. At the same time the method satisfies all requirements for XiL testing. Functional tests of multiple interacting vehicle controllers have been successfully carried out. In the performed feasibility study simulation-based tests uncovered an insufficient control stability of the CACC. Upcoming series developments and homologations of in-vehicle C-ITS software and hardware can be supported by the new virtual test environment to overcome connectivity, reproducibility and cost efficiency limitations of physical test environments. Next steps include proving the method in use for series development and extending it to cover vehicle-to-infrastructure use cases.

Modeling and evaluation of enhanced reception techniques for ADS-B signals in high interference environments

The RTCA (Radio Technical Commission for Aeronautics) DO-260B document has stimulated in latest years the adoption of novel algorithms to improve the ability of receivers to detect and decode ADS-B (Automatic Dependent Surveillance-Broadcast) signals, with particular emphasis on preamble detection, declaration of bit state and confidence level, detection and correction of errors. Motivated by an industry-driven research project, this paper reports on performance analysis of a set of enhanced techniques that we have implemented for detection and decoding of ADS-B signals transmitted at 1090 MHz carrier frequency also in high interference conditions. An extensive set of results has been derived through a specifically developed simulation environment, able to closely model a wide range of operational scenarios by generating ADS-B frames and Mode A/C interfering signals. The simulation environment also includes an implementation of two RF (Radio Frequency) receiver chains that refer to a linear amplifier and a logarithmic amplifier, respectively. The investigations are mainly focused on evaluating the impact of the interference generated by Mode A/C replies on preamble detection and data decoding for ADS-B signals. In this regard, the ability of enhanced reception techniques to improve detection performance is assessed. Numerical results obtained from extensive simulation runs are reported and commented. They actually demonstrate that enhanced techniques are essential to guarantee adequate detection performance in the harsh environments envisaged by increased intensity of air traffic and the extensive use of ADS-B for traffic control.

A realistic simulation platform for multi-quadcopter search using downward facing cameras

This paper presents a cross platform simulation environment, in a hybrid centralized-decentralized architecture, for multi-quadcopter search problem developed using MATLAB and Gazebo simulator in Robot Operating System (ROS) environment. Multiple quadcopters equipped with downward facing camera are deployed in a search area to gather information such as presence of targets of interest. Search is modeled as reducing uncertainty density, a metric of lack of information about the presence (or absence) of the targets of interest. The simulation platform developed will be a very useful tool for conducting realistic simulation experiments to validate the proposed search strategy and to make a comparative study of its performance in terms of time for the search process, with parameters such as camera search effectiveness models, sensor range, the number of robots, to decide on the parameters best suited for a given situation. We provide simulation results demonstrating the proposed search strategy using the developed simulation environment.

Fuzzy Decision Efficiency for Multiprocessor Architecture Configuration

Dynamic voltage/frequency scaling (DVFS) has been an efficient technique in exploiting multi-processors configurable characteristics. However, for large class of embedded real time applications, changing processors frequency interferes with tasks deadline guarantee. Under homogenous multiprocessor architecture, we are interested in intelligent offline/online reconfiguration based on fuzzy inference system.This paper investigates the efficiency of using fuzzy decision in multiprocessor architecture configuration. Goals of decision making are system schedulability guarantee and energy consumption optimization. Experiments concern real time periodic tasks scheduled with global EDF and realized over a developed simulation environment that supports DVFS technique. Different simulations were realized on H264 Video Decoder in order to evaluate the proposed approach response.

Vertical Takeoff and Landing of Flexible Wing Kite Power Systems

In this work, a novel vertical takeoff and landing methodology for flexible wing kite power systems is presented. Starting from a basic mast-based launching and landing concept, the operational envelope will be enlarged using the external assistance of a multicopter. The multicopter is used to drag the kite along a specified launching path until the operational altitude is reached, where the kite is detached and steered to its characteristic parking position while the multicopter lands. The landing of the kite will be conducted without multicopter assistance, and solely the winch will be used to pull the kite toward the ground station. For all maneuvers, flight control algorithms are presented, and the feasibility of the proposed methodology is analyzed using a developed simulation environment incorporating models for the kite, multicopter, ground station, and the tethers that connect the individual subsystems.

Efficient and Accurate Electromagnetic Analysis of Three-Dimensional Nano-Optical Structures

We present computational analysis of optical nanostructures, including but not limited to frequency-selective surfaces, metamaterials, nanoantennas, nanowires, and photonic crystals. A rigorous implementation based on surface integral equations and the multilevel fast multipole algorithm is developed for the analysis of such three-dimensional complex structures, without resorting to infinity, self-similarity, periodicity or homogeneity assumptions. The developed simulation environment provides accurate analysis of nanooptical structures to expand our knowledge on these important components of the state-of-the-art technology.

Development of High Precision Vehicle Dynamic Model with an Intelligent Torque Transfer System (All-Wheel Drive System)

High precision vehicle simulation environment is required for development of control system of any newly suggested intelligent system. Hence, a high precision full-vehicle simulation environment integrated with an intelligent torque transfer system should be developed for an advanced control logic for enhancement of vehicle stability. In the perspective of making enhanced AWD system, there are many kinds of methods to make the system. And a controller part of the AWD module is regarded as a major part of the system development in consideration of enhancement of the vehicle stability with the suggested AWD system. Therefore, in this study, high precision full-vehicle simulation environment is developed for the development of an intelligent control system of the AWD module. In order to make models for the simulation, vehicle test is performed with a commercial vehicle, and the several performance tests of the developed AWD system are also conducted in a laboratory. Then, the simulation environment comprised of several models of important sub-systems is developed based on the previously conducted test results, and the developed simulation environment is verified by comparing the simulation results to the test results.

ARACHNE: A neural-neuroglial network builder with remotely controlled parallel computing.

Creating and running realistic models of neural networks has hitherto been a task for computing professionals rather than experimental neuroscientists. This is mainly because such networks usually engage substantial computational resources, the handling of which requires specific programing skills. Here we put forward a newly developed simulation environment ARACHNE: it enables an investigator to build and explore cellular networks of arbitrary biophysical and architectural complexity using the logic of NEURON and a simple interface on a local computer or a mobile device. The interface can control, through the internet, an optimized computational kernel installed on a remote computer cluster. ARACHNE can combine neuronal (wired) and astroglial (extracellular volume-transmission driven) network types and adopt realistic cell models from the NEURON library. The program and documentation (current version) are available at GitHub repository https://github.com/LeonidSavtchenko/Arachne under the MIT License (MIT).

A multi-domain modelling and verification procedure within MBSE approach to design propulsion systems for road electric vehicles

The paper deals with the model based systems engineering (MBSE) approach, focused on the designing process of propulsion systems for road electric vehicles. In particular, the paper adopts multi-domain Modelling, in accordance with a top-down approach. The process, in fact, starts from the main requirement analysis of the road electric vehicle which is considered as reference. Then, a wide range of parameters, related to the characteristics of propulsion system components and resistance forces, are evaluated to build a parametric model of the propulsion system running on a road. In this way, a procedure for the evaluation of vehicle performance is accomplished within the developed simulation environment. Therefore, the procedure allows all the requirements to be satisfied, under different operative conditions, through an iterative procedure of verification for the imposed parameters. The tested operative conditions are represented in this paper by standard driving cycles, expressed in terms of vehicle speed and autonomy requirement.

Tool life management of unmanned production system based on surface roughness by ANFIS

This research focuses on to develop monitoring systems that can detect surface roughness by using adaptive neuro-fuzzy inference system (ANFIS) for the unmanned production system. Cutting force is one important characteristic variable to be monitored in the cutting processes to determine tool life regarding tool breakage, tool wear, and surface roughness (Ra) of the workpiece. The principal presumption was that the cutting forces are normally increased by the wear of the tool. Therefore, the ANFIS method is used to extract the features of tool states from cutting force signals. Input parameters for making an ANFIS model are Speed, feed, depth of cut, cutting force and output in term of surface roughness. A piezoelectric dynamometer measured the forces. The experimental forces and surface roughness were utilized to train the developed simulation environment based on ANFIS modeling. By tool condition monitoring system, the machining process can be on-line monitored for the unmanned production system. The achieved Correlation coefficient (R) is 0.9528 and average percentage error is 7.38 %. In this research, we predict the surface roughness of a workpiece by using the ANFIS modeling and surface roughness can be used for tool life management and enables it for monitoring of unmanned production system.

Analysis of Integrated Radiant Slab Heating and Cooling Systems for Residential Buildings

ABSTRACTThis paper presents a simulation environment developed to assess the energy use specific to integrated radiant heating and cooling systems. The developed simulation environment combines a transient finite difference solution for the two-dimensional model of an integrated radiant slab heating and cooling system with a resistance capacitance (RC) thermal network model for a multifloor building. The developed model of the integrated radiant system is able to account for thermal bridge effects on the energy performance of multifloor buildings. The predictions of the developed simulation environment are verified against those obtained from a detailed whole-building energy simulation tool under specific conditions. The developed simulation environment is then used to investigate the impact of thermal bridge effects on the performance of an integrated radiant heating and cooling system. Thermal bridging can affect significantly the energy performance of the integrated radiant systems by up to 8%. Several...

Development of a Smart Grid Simulation Environment

With the increased integration of renewable energy sources the interaction between energy producers and consumers has become a bi-directional exchange. Therefore, the electrical grid must be adapted into a smart grid which effectively regulates this two-way interaction. With the aid of simulation, stakeholders can obtain information on how to properly develop and control the smart grid. In this paper, we present the development of an integrated smart grid simulation model, using the Anylogic simulation environment. Among the elements which are included in the simulation model are houses connected to a renewable energy source, and batteries as storage devices. With the use of the these elements a neighbourhood model can be constructed and simulated under multiple scenarios and configurations. The developed simulation environment provides users better insight into the effects of running different configurations in their houses as well as allow developers to study the inter-exchange of energy between elements in a smart city on multiple levels.

Development of a simulation analysis environment for ventilated slab systems

In this paper, a new simulation environment is presented to evaluate the energy performance of ventilated slab systems in multi-floor buildings. The simulation environment combines a transient two-dimensional finite difference solution of a ventilated slab system comprising slab-wall joints with thermal network model for indoor spaces and associated exterior walls. The developed simulation environment can assess the impact of thermal bridging effects on both heating and cooling building thermal loads. First, the predictions of the developed simulation environment are verified against those obtained from a detailed whole-building energy simulation tool when thermal bridging effects are neglected. Then, a series of parametric analyses are performed to determine the performance of ventilated slab systems under various design and operating conditions considering the thermal bridging effects. It is found that the energy performance of ventilated slab systems and thermal bridging impact depend on a wide range of factors including size of the slab, supply air inlet temperature, air mass flow rate, core diameter, core pitch, and depth of hollow cores. In particular, it is found that the thermal bridge affects significantly the energy performance of ventilated slab systems and can increase both heating and cooling energy consumptions by 17% and 11%, respectively.

Simulation of protection mechanisms against botnets.

To create effective mechanisms of protection against botnets, it is necessary to investigate the behavior of botnets and their impact on the operation of computer networks, as well as methods for botnet detection and counteraction to them. The paper investigates protection mechanisms against botnets, which are proliferated by worm propagation techniques and carry out DDoS attacks. As a toolkit to study of botnets and protect mechanisms we developed the simulation environment. The paper considers the architecture of the simulation environment implemented and a multitude of experiments which show ample opportunities of the developed simulation environment for research of botnets and protection mechanisms.