Visual Simulation Environment Research Articles

First-principles algorithms for ship motion simulation based on ARMA and trochoidal wave models

An approach for the direct simulation of ship behavior in heavy sea conditions using modern computers methods is described. The approach includes a model for wind-driven waves, algorithms for hydrodynamic pressure calculation, a solution of the diffraction problem, and the integration of the approach into a problem solution environment. An ARMA (autoregressive-moving average) model is used for the simulation of a hydrodynamically adequate spatial-temporal wave surface and integrated with a calculation of hydrodynamic pressure at any point under the wave surface. The integration of the wave pressure over the ship hull and the solution of the diffraction problem provides the excitation forces and moments and permits direct numerical simulation of ship motions in waves. An effective numerical implementation of the algorithms with mapping to modern computer architecture is described. The combination of the numerical algorithms with a visual simulation environment is presented as a virtual testbed.

Robust nonlinear path-tracking control of vector-propelled AUVs in complex sea conditions

Aiming to address the trajectory tracking problem of vector propulsion autonomous underwater vehicles (vector AUVs) under complex sea conditions, this paper proposes a dynamic control system based on vector propulsion (DS-Vector). The vector AUV has the vector characteristics of four tilt thrusters and is highly maneuverable. Based on the approximate kinematics and dynamics equations of the vector AUV under the action of current disturbance obtained through analysis, the proposed DS-Vector has a motion control module and force distribution control module. The motion control module adopts the control method by combining the nonsingular fast terminal sliding mode control based on an adaptive disturbance observer (NTSMC-ADO) and PID control law, while the force distribution control module selects the least square (LS) method. The effectiveness and robustness of the proposed DS-Vector are verified in an underwater visual simulation environment. To verify the superiority of the NTSMC-ADO designed in this paper, three other advanced control laws are used in DS-Vector for comparison. The results show that NTSMC-ADO has better anticurrent interference and better position tracking control response and is more robust than the other three advanced control laws.

Innovative Approach for the Study of Tuning Circuit with Open Source Tools

In the new age of an online teaching-learning process, present instructional approach expects students to be an active learner, which necessitates a new instructional tool that can provide opportunity for active learning. The use of technology in teaching-learning has become a key factor which helps in conceptual understanding. Simulation being one of the valuable instructional tools renders an opportunity to visualize the concepts and facilitate to build the mental model. The present work proposes a study of electrical circuit experiments performed using open source tools such as XCOS and expEYES. These tools facilitate in developing higher order critical thinking and analysis skill. XCOS being one of the tools in Scilab provides the visual simulation environment for varying the input parameters of the model. The RL, RC, and RLC tuning circuits are virtually modeled by using the XCOS and the real circuits made with expEYES, which facilitates the study of response curves with ease. In the later case, the results obtained by using expEYES compared with the results of XCOS. In addition, the study explains how such response of simple linear circuits can be extended in different applications. Demonstrations and visualization of the response curve and phase flow of linear circuits will overlay the way to understand experimental and numerical results. This innovative approach can be used in the classroom demonstration of a harmonic oscillator and resonant circuits in advance level physics and engineering laboratories.

РАЗРАБОТКА СИСТЕМ КОНТРОЛЯ ВЫСЕВА СЕМЯН ДЛЯ ЗЕРНОВЫХ СЕЯЛОК

The paper discusses technical aspects involved in developing seeding control systems for grain seeders and sowing machines. Construction and technological parameters of seeding control systems are based on the analysis of the available machinery. As a result an operation-performing unit was constructed and tested in field trials. The RatinalRose visual simulation environment was used to design the software of the seeding control system. The environment allowed for interpreting the volume concentration of particles. A procedure for collecting and presenting data was developed. COMPAS com106 puter program was used to create a 3D design of the sensor and measure its parameters, then the sensor case was made using a 3D printer. Field trials involved comparing 2 identical drills under identical conditions. The drill equipped with the seeding control system had better indices of time saving and efficiency (by 22 %). The study results allowed us to develop the software for the seeding control system and determine the optimal design and process parameters of the seeding control sensor for a pneumatic drill in order to reduce clogging in the seed pipes and improve the quality of seed distribution.

End-to-End Automated Lane-Change Maneuvering Considering Driving Style Using a Deep Deterministic Policy Gradient Algorithm.

Changing lanes while driving requires coordinating the lateral and longitudinal controls of a vehicle, considering its running state and the surrounding environment. Although the existing rule-based automated lane-changing method is simple, it is unsuitable for unpredictable scenarios encountered in practice. Therefore, using a deep deterministic policy gradient (DDPG) algorithm, we propose an end-to-end method for automated lane changing based on lidar data. The distance state information of the lane boundary and the surrounding vehicles obtained by the agent in a simulation environment is denoted as the state space for an automated lane-change problem based on reinforcement learning. The steering wheel angle and longitudinal acceleration are used as the action space, and both the state and action spaces are continuous. In terms of the reward function, avoiding collision and setting different expected lane-changing distances that represent different driving styles are considered for security, and the angular velocity of the steering wheel and jerk are considered for comfort. The minimum speed limit for lane changing and the control of the agent for a quick lane change are considered for efficiency. For a one-way two-lane road, a visual simulation environment scene is constructed using Pyglet. By comparing the lane-changing process tracks of two driving styles in a simplified traffic flow scene, we study the influence of driving style on the lane-changing process and lane-changing time. Through the training and adjustment of the combined lateral and longitudinal control of autonomous vehicles with different driving styles in complex traffic scenes, the vehicles could complete a series of driving tasks while considering driving-style differences. The experimental results show that autonomous vehicles can reflect the differences in the driving styles at the time of lane change at the same speed. Under the combined lateral and longitudinal control, the autonomous vehicles exhibit good robustness to different speeds and traffic density in different road sections. Thus, autonomous vehicles trained using the proposed method can learn an automated lane-changing policy while considering safety, comfort, and efficiency.

Application of the Environmental Sensation Learning Vehicle Simulation Platform in Virtual Reality

The use of simulation technologies in learning has received considerable attention in recent years, but few studies to date have focused on vehicle driving simulation systems. In this study, a vehicle driving simula-tion system was developed to support novice drivers in practicing their skills. Specifically, the vehicle driv-ing simulation system was designed according to various driving environmental factors that may be encoun-tered while traveling, including roads, time, weather, ambient scenery, traffic flow, and vehicle of the driver. Moreover, to improve the reality of the vehicle driving simulation system, software and hardware are rede-signed and updated during the research, particularly for increasing the reality of the simulation environment and future extensions of the driving simulation system. Accordingly, drivers can construct their own neces-sary driving situations so as to improve their skills. Experimentation in the visual simulation environment may reduce external factors of drivers, and may be repeated, so that it is a better approach to conduct re-search through the visual simulation technology.

Cloud-hosted simulation-as-a-service for high school STEM education

Despite their advanced status, nations such as the United States of America continue to face a STEM (science, technology, engineering and mathematics) crisis in their education system. Lack of effective teaching modalities that can leverage real-world examples to stimulate student interest in STEM concepts are identified as one of the reasons for this crisis. To address these challenges, our research is investigating the use of innovative and attractive modeling and simulation frameworks for concurrent, interactive and collaborative STEM education where vehicular traffic serves as the real-world example to reify STEM concepts. Existing traffic-related tools, such as traffic simulators, however, do not provide: (1) intuitive abstractions to construct, refine, and simulate various traffic models that are commensurate to the level of high school students, (2) concurrent and scalable model execution, and (3) collaborative learning environments. On the other hand, although intuitive abstractions such as Google Maps exist, these abstractions do not support semantics for dynamic behavior, which is representative of real-world traffic scenarios. To overcome both these challenges and address the STEM problem, this paper presents a Cloud-based, Collaborative, and Scaled-up Modeling and Simulation Framework for STEM Education called C2SuMo. The key contribution of this paper lies in the design and implementation of a cloud-based, elastic modeling and simulation framework that provides an intuitive, model-driven, collaborative, and concurrent visual simulation environment for STEM education. The paper also reports on insights we gained conducting a user study involving over sixty high school students.

Bio-inspired modeling and implementation of the ocelli visual system of flying insects.

Two visual sensing modalities in insects, the ocelli and compound eyes, provide signals used for flight stabilization and navigation. In this article, a generalized model of the ocellar visual system is developed for a 3-D visual simulation environment based on behavioral, anatomical, and electrophysiological data from several species. A linear measurement model is estimated from Monte Carlo simulation in a cluttered urban environment relating state changes of the vehicle to the outputs of the ocellar model. A fully analog-printed circuit board sensor based on this model is designed and fabricated. Open-loop characterization of the sensor to visual stimuli induced by self motion is performed. Closed-loop stabilizing feedback of the sensor in combination with optic flow sensors is implemented onboard a quadrotor micro-air vehicle and its impulse response is characterized.

Ecosystem modelling for ecosystem-based management of bivalve aquaculture sites in data‑poor environments

AEI Aquaculture Environment Interactions Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AEI 4:117-133 (2013) - DOI: https://doi.org/10.3354/aei00078 Ecosystem modelling for ecosystem-based management of bivalve aquaculture sites in data‑poor environments R. Filgueira1,3,*, J. Grant1, R. Stuart2, M. S. Brown1 1Department of Oceanography, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada 2PO Box 60, Englishtown, Nova Scotia B0C 1H0, Canada 3Present address: Department of Fisheries and Oceans, Gulf Fisheries Centre, Science Branch, PO Box 5030, Moncton, New Brunswick E1C 9B6, Canada *Email: ramonf@dal.ca ABSTRACT: Although models of carrying capacity have been around for some time, their use in aquaculture management has been limited. This is partially due to the cost involved in generating and testing the models. However, the use of more generic and flexible models could facilitate the implementation of modelling in management. We have built a generic core for coupling biogeochemical and hydrodynamic models using Simile (www.simulistics.com), a visual simulation environment software that is well-suited to accommodate fully spatial models. Specifically, Simile integrates PEST (model-independent parameter estimation, Watermark Numerical Computing, www.pesthomepage.org), an optimization tool that uses the Gauss-Marquardt-Levenberg algorithm and can be used to estimate the value of a parameter, or set of parameters, in order to minimize the discrepancies between the model results and a dataset chosen by the user. The other critical aspect of modelling exercises is the large amount of data necessary to set up, tune and groundtruth the ecosystem model. However, ecoinformatics and improvements in remote sensing procedures have facilitated acquisition of these datasets, even in data-poor environments. In this paper we describe the required datasets and stages of model development necessary to build a biogeochemical model that can be used as a decision-making tool for bivalve aquaculture management in data-poor environments. KEY WORDS: Aquaculture · Carrying capacity · Ecological modelling · Ecosystem-based management · Fully spatial model · Marine spatial planning Full text in pdf format PreviousNextCite this article as: Filgueira R, Grant J, Stuart R, Brown MS (2013) Ecosystem modelling for ecosystem-based management of bivalve aquaculture sites in data‑poor environments. Aquacult Environ Interact 4:117-133. https://doi.org/10.3354/aei00078 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AEI Vol. 4, No. 2. Online publication date: July 18, 2013 Print ISSN: 1869-215X; Online ISSN: 1869-7534 Copyright © 2013 Inter-Research.

Designing and Realizing of UAV Simulation System

This paper discusses an Unmanned Aerial Vehicle simulation system design and implementation, which focuses on the system design, system management, software development, and the information flow management of the whole system. To simulate battlefield environments, this system provides a clear and visual expression way for complex system design. Besides, it provides services for the design, integration testing, experiment, verification and evaluation of complex system. The main tasks of the system include: establish flight control simulation model; construct three-dimensional visual environment model and three-dimensional entity model; In the case of aircraft loading, drive various kinds of simulation modules, use related model of aircraft task / path planning module; display the typical use of aircraft system visually, as combining with three-dimensional visual simulation environment. Based on VC++ and MultiGen Creator/Vega, this simulation system probes into three-dimensional modeling technology and visual simulation-driven. It proposes general techniques route, improves work efficiency and has a wide range of application.

Flight Trajectory Visual Simulation Technology of Space-based Reentry Vehicles

This paper is mainly devoted to performing flight trajectory visual simulation of space-based reentry vehicle through the method based on two professional software —MultiGen Creator and Vega Prime. In this approach, scene models and object models are designed with MultiGen Creator. MultiGen Vega Prime is utilized to built movement's models and initial visual simulation environment. The thesis results in constructing a realistic three-dimensional flight virtual environment to simulate flight trajectory of space-based reentry vehicle. According to the approach, characteristics of MultiGen Creator and Vega Prime are investigated, technique conclusions of designing visual models, building simulation environment, performing drive and control of visual simulation are summarized.

URAV Simulation Training System Based on Aerosim and Google Earth

In order to solve the difficulties of traditional simulation training method on unmanned reconnaissance aerial vehicle, such as the low environment fidelity, difficulty of modeling and long cycle of development, a simulation training method based on Google Earth is put forward. The 6-DOF motion system of URAV is established through Matlab/Simulink. The visual simulation environment which is close to real scenes is formed though GE and software of SketchUp, and the visualization of flight data and elevation information of the region are also obtained through the software of GMS Aircraft Instrument and Measurement Studio. Experiments show that the method has satisfactory effects and its functions also can be strengthened, therefore it provides reference to related researchers.

SERA: a secure energy reliability aware data gathering for sensor networks

Wireless sensor networks are used in many applications in military, ecology, health, and other areas. These applications often include the monitoring of sensitive information making the security issue one of the most important aspects to consider in this field. However, most of protocols optimize for the limited capabilities of sensor nodes and the application specific nature of the networks, but they are vulnerable to serious attacks. In this paper, a Secure Energy and Reliability Aware data gathering protocol (SERA) is proposed, which provides energy efficiency and data delivery reliability as well as security. The proposed protocol's security was confirmed by a formal verification carried out using the AVISPA tool and analysis of the most common network layer attacks such as selective forwarding, sinkhole, Sybil, wormhole, HELLO flood, and acknowledgment spoofing attacks. Additionally, a visual simulation environment was developed to evaluate the performance of the proposed protocol.

An Approach to Stable Walking over Uneven Terrain Using a Reflex‐Based Adaptive Gait

This paper describes the implementation of an adaptive gait in a six‐legged walking robot that is capable of generating reactive stepping actions with the same underlying control methodology as an insect for stable walking over uneven terrains. The proposed method of gait generation uses feedback data from onboard sensors to generate an adaptive gait in order to surmount obstacles, gaps and perform stable walking. The paper addresses its implementation through simulations in a visual dynamic simulation environment. Finally the paper draws conclusions about the significance and performance of the proposed gait in terms of tracking errors while navigating in difficult terrains.

A Visual Simulation Environment for Teaching Power System Stability

Computer-mediated teaching can be very effective in enhancing students' understanding of concepts and increasing their involvement in the classroom. This paper presents an interactive visual simulation tool to assist instructors in demonstrating power system stability phenomena. Power flow computations, used to initialise the simulation, are carried out using Matlab, whereas the simulation is implemented using Simulink. The Graphical User Interface (GUI), which controls the whole program and is constructed using C#, provides the capability to change system parameters/operating points interactively. To further the grasp of stability notions and reinforce the sense of seamless photorealistic interaction with the simulation, visual animation illustrating the synchronous generator along with virtual analogue meters, represented as ActiveX controls to portray inherent machine variables, are constructed. Several test cases, which cover various power system stability events, are described and analysed.

A simulation model of carrying capacity for mussel culture in a Norwegian fjord: Role of induced upwelling

Shellfish carrying capacity is determined by the interaction of cultured species with the ecosystem, principally constrained by environmental characteristics, especially food availability. A recent experiment carried out in Lysefjord (SW Norway) has shown that induced upwelling of nutrient-rich deeper water stimulated phytoplankton growth, potentially increasing the carrying capacity for mussel cultivation. With the aim of assisting in development of sustainable mussel culture in Lysefjord, an object-oriented model of aquaculture–environment interactions and mussel carrying capacity was constructed. A multiple box ecosystem model was developed within the visual simulation environment of Simile software allowing explicit coupling between boxes, which represent regions of the fjord. Once the box model was developed and calibrated, subsequent application of PEST (Parameter ESTimation) allowed optimization of different parameters of the model in order to manage mussel production according to carrying capacity criteria. The Simile model and the simultaneous application of PEST allowed several scenarios taking into account different stocking densities, upwelling alternatives, and the creation of new cultivation areas.

Nonlinear System Control Using Adaptive Neural Fuzzy Networks Based on a Modified Differential Evolution

This study presents an adaptive neural fuzzy network (ANFN) controller based on a modified differential evolution (MODE) for solving control problems. The proposed ANFN controller adopts a functional link neural network as the consequent part of the fuzzy rules. Thus, the consequent part of the ANFN controller is a nonlinear combination of input variables. The proposed MODE learning algorithm adopts an evolutionary learning method to optimize the controller parameters. For design optimization, a new criterion is introduced. A hardware-in-the loop control technique is developed and applied to the designed ANFN controller using the MODE learning algorithm. The proposed ANFN controller with the MODE learning algorithm (ANFN-MODE) is used in two practical applications-the planetary-train-type inverted pendulum system and the magnetic levitation system. The experiment is developed in a real-time visual simulation environment. Experimental results of this study have demonstrated the robustness and effectiveness of the proposed ANFN-MODE controller.

Assessing water quality management options in the Upper Litani Basin, Lebanon, using an integrated GIS-based decision support system

The widespread and relentless discharge of untreated wastewater into the Upper Litani Basin (ULB) river system in Lebanon has reached staggering levels rendering its water unfit for most uses especially during the drier times of the year. Despite the call by governmental and non-governmental agencies to develop several wastewater treatment plants and sewage networks in an effort to control this problem, these efforts do not seem to be coordinated or based on comprehensive and integrated assessments of current and projected conditions in the basin. This paper provides an overview of the development and implementation of an integrated decision support system (DSS) designed to help policy makers and other stakeholders have a clearer understanding of the key factors and processes involved in the sewage induced degradation of surface water quality in the ULB, and formulate, assess and evaluate alternative management plans. The DSS is developed based on the WEAP model, which provides a GIS based and visual simulation environment and scenario management and analysis capabilities. The DSS was used to assess two main water quality management plans taking into consideration hydrological, spatial and seasonal variabilities. An incremental cost-effectiveness analysis was conducted to identify best buy plans. The results have confirmed the gravity of this problem and demonstrated the importance of taking immediate action on curbing this onslaught on this valuable and scarce fresh water resource.

Simulation of the hydrological processes on reconstructed watersheds using system dynamics

Reconstruction of disturbed watersheds is a common practice by the oil sands industry in northern Alberta, Canada. The reconstruction and restoration of the watershed hydrology are required as part of the reclamation mandated by Alberta Environment for mine closure. Assessment of the hydrological performance of the reconstructed watersheds is essential to ensure a sustainable reclamation strategy. A conceptual lumped system dynamics watershed (SDW) model is developed and calibrated in this study. The model, built within an object-based simulation environment, is capable of simulating the various hydrological processes in the reconstructed watersheds with good accuracy. STELLA Software is used as an object-based simulation environment that allows visual computations. The SDW model developed combines both physically-based and empirical formulations to replicate the hydrological system mathematically. The system dynamics approach along with the visual simulation environment help in developing a simulation-for-learning model, not only simulation for prediction. The model is successfully calibrated and validated; the results show that the SDW model is capable of simulating the various hydrological processes (soil moisture, evapotranspiration and runoff) with good accuracy. The SDW model can help in the assessment of the short- and long-term performances of the reconstructed watersheds, thus providing a useful decision-aid tool for the mining industry.

Dynamic Conflict Management in Large-Scale Design and Construction Projects

The construction industry plays a major role in both the economy and infrastructure project delivery worldwide. However, one major critical characteristic of the construction industry is the high cost incurred by the resolution of arising conflicts in projects. As a result, project managers are seeking ways to avoid conflicts and resolve them effectively and equitably when they happen. This paper discusses the dynamic nature of conflicts in terms of their evolution and escalation within a project and the interaction between conflicts and dispute avoidance and resolution techniques (DART). The paper also presents the background and development of a conflict management system, entitled the DART Simulator (DART-S). The intent of the DART-S is to provide project managers with a comprehensive and integrated approach to evaluate the impact of a DART implementation on the reduction of conflicts. The simulator was built using a system dynamic modeling within a visual simulation environment. The core of the simulator was developed by using data from literature on the nature of conflicts, dispute resolution processes, and the potential effectiveness of 46 different DART-S on conflict avoidance and resolution. The simulator was then tested and verified with a case study comparing the traditional two-step dispute resolution process with a five-step dispute resolution process. The results of this comparison clearly show that the five-step dispute resolution process is able to decrease the initial number of conflicts of a project, reduce the number of conflicts which may escalate to a higher step in the resolution process, and provide resolutions of conflicts before they reach litigation. By quantifying the amount of conflicts, evaluating the evolution of conflicts, and assessing the impact of DART implementation on conflict escalation, the DART-S provides project managers with an integrated strategy for conflict management.