Готові списки джерел за темами / Dynamic modeling and simulations / Статті в журналах

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Статті в журналах з теми "Dynamic modeling and simulations"

Автор: Grafiati

Опубліковано: 4 червня 2021

Оновлено: 6 лютого 2022

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HUANG, HAI, YONG-JIE PANG, JIANG LI, SHAO-WEI FAN, XIN-QING WANG, and HONG LIU. "UNDERACTUATED HAND DYNAMIC MODELING, ITS REAL-TIME SIMULATION, AND CONTROL." International Journal of Humanoid Robotics 07, no. 04 (2010): 609–34. http://dx.doi.org/10.1142/s021984361000226x.

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The forward and inverse dynamic models of the underactuated 2-DOF finger have been established in this article based on virtual spring approach. This approach not only avoids the solution of differential-algebraic equations but also leads to a completely decoupled dynamic model that is ideal for directly inverse dynamic analysis, real-time dynamic simulation and control. To verify this approach, an underactuated 3-joint finger has been brought forward. Simulation results from Matlab/Simulink are consistent with those obtained from ADAMS grasp simulations. For the hand real-time dynamic control, the velocity observer has been established based on the dynamic model, the adaptive curve fitting with the observer has obtained precise velocity signals, made up the uncertain parameters such as torsion spring, inertial, damps, etc. and achieved ideal results. By applying dynamics model and observer, the force-based impedance control can realize more accurate and stable force control during grasp.

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Kao, B. G. "A Three-Dimensional Dynamic Tire Model for Vehicle Dynamic Simulations." Tire Science and Technology 28, no. 2 (2000): 72–95. http://dx.doi.org/10.2346/1.2135995.

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Abstract Traditional multibody dynamic (MBD) tire models concentrate on the tire patch force development and the tire in-plane characteristics. The tire lateral dynamics and nonlinear effects caused by the tire compliances during rough terrain driving and severe maneuvers are mostly neglected in vehicle analytical simulations. The tire finite element models, though capable of dealing with these phenomena, are basically not designed for quick vehicle dynamic evaluations. A simple three-dimensional (3-D) MBD tire model for full vehicle performance and maneuvering simulations over various road surfaces is therefore desirable for the ever expanding analysis capabilities and the improved accuracy of the computer-aided vehicle design analysis. In this paper a tire modeling concept to extend the in-plane dynamic tire model to full 3-D tire dynamics is proposed. Essentially, this tire model divides the traditional tire/wheel system model into three elements: two rigid bodies representing the wheel mass/inertia and the tire tread mass/inertia, and a spring/damper representing the sidewall visco-elasticity. Thus, 6 degrees-of-freedom (DOFs) are added for each tire over traditional tire models. Using any existing tire patch force calculation model, this proposed model can be used to simulate full 3-D dynamic responses of a vehicle. To implement this model, techniques to extract the nonlinear spring rates of the sidewalls and to enhance the tire patch force calculations over uneven terrains are explained in this paper. Results of the vehicle simulation using this tire model were compared with measured field data. They showed that this tire modeling concept yields a practical representation for tire 3-D nonlinear dynamic characteristics.

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Dinkelbach, Jan, Ghassen Nakti, Markus Mirz, and Antonello Monti. "Simulation of Low Inertia Power Systems Based on Shifted Frequency Analysis." Energies 14, no. 7 (2021): 1860. http://dx.doi.org/10.3390/en14071860.

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New types of power system transients with lower time constants are emerging due to the replacement of synchronous generation with converter interfaced generation and are challenging the modeling approaches conventionally applied in power system simulation. Quasi-stationary simulations are based on classical phasor models, whereas EMT simulations calculate the instantaneous values of models in the time domain. In addition to these conventional modeling approaches, this paper investigates simulation based on dynamic phasor models, as has been proposed by the Shifted Frequency Analysis. The simulation accuracy of the three modeling approaches was analyzed for characteristic transients from the electromagnetic to the electromechanical phenomena range, including converter control as well as low inertia transients. The analysis was carried out for systems with converter interfaced and synchronous generation whilst considering the simulation step size as a crucial influence parameter. The results show that simulations based on dynamic phasors allow for larger step sizes than simulations that calculate the instantaneous values in the time domain. This can facilitate the simulation of more complex component models and larger grid sizes. In addition, with dynamic phasors, more accurate simulation results were obtained than with classical phasors, in particular—but not exclusively—in a low inertia case. Overall, the presented work demonstrates that dynamic phasors can enable fast and accurate simulations during the transition to low inertia power systems.

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Shah, Yash, Andrea Vacca, and Sadegh Dabiri. "Air Release and Cavitation Modeling with a Lumped Parameter Approach Based on the Rayleigh–Plesset Equation: The Case of an External Gear Pump." Energies 11, no. 12 (2018): 3472. http://dx.doi.org/10.3390/en11123472.

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In this paper, a novel approach for the simulation of cavitation and aeration in hydraulic systems using the lumped parameter method is presented. The presented approach called the Hybrid Rayleigh–Plesset Equation model is derived from the Rayleigh–Plesset Equation representative of bubble dynamics and overcomes several shortcomings present in existing lumped parameter based cavitation modeling approaches. Models based on static approximations do not consider the non-equilibrium effects of phase change on the system and incorrectly predict the system dynamics. On the other hand, the existing dynamic cavitation modeling strategies account for the non-equilibrium effects of phase change but express the evolution of phases through approximations of the Rayleigh–Plesset Equation (such as exclusion of nonlinear interactions in bubble dynamics), which often lead to physically unrealistic time-scales of bubble growth or dissolution. This paper presents a dynamic model for cavitation which is capable of predicting cavitation in hydraulic systems while preserving the nonlinear dynamics arising from the Rayleigh–Plesset Equation. The derived model determines the evolution of phases in terms of physically realizable parameters such as the bubble radius and the nuclei density, which can be estimated or determined experimentally. The paper demonstrates the effectiveness of the derived modeling approach with the help of numerical simulations of an External Gear Machine. Results from the simulations employing the proposed model are compared with an existing dynamic cavitation modeling approach and validated with experimental results over a range of dynamic parameters.

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Mueller, Eric, William Mell, and Albert Simeoni. "Large eddy simulation of forest canopy flow for wildland fire modeling." Canadian Journal of Forest Research 44, no. 12 (2014): 1534–44. http://dx.doi.org/10.1139/cjfr-2014-0184.

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Large eddy simulation (LES) based computational fluid dynamics (CFD) simulators have obtained increasing attention in the wildland fire research community, as these tools allow the inclusion of important driving physics. However, due to the complexity of the models, individual aspects must be isolated and tested rigorously to ensure meaningful results. As wind is a driving force that can significantly dictate the behavior of a wildfire, the simulation of wind is studied in the context of a particular LES CFD model, the Wildland–urban interface Fire Dynamics Simulator (WFDS). As WFDS has yet to be tested extensively with regard to wind flow within and above forest canopies, a study of its ability to do so is carried out. First, three simulations are conducted using periodic boundary conditions. Two of these assume a spatially heterogeneous forest and one models wind downstream of a canopy edge. Second, two simulations are conducted with specified “inflow” conditions using two inflow profiles: one static and one dynamic (driven by a precursor simulation). Using periodic boundary conditions, the model is found to generate profiles of mean velocity and turbulent statistics that are representative of experimental measurements. The dynamic inflow scenario is found to perform better than the static case.

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Wang, Peng, Xinliang Tian, Wenyue Lu, Zhihuan Hu, and Yong Luo. "Dynamic modeling and simulations of the wave glider." Applied Mathematical Modelling 66 (February 2019): 77–96. http://dx.doi.org/10.1016/j.apm.2018.08.027.

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Chen, Qiu Yue, and Li Zeng. "Dynamic Modeling and Simulation of the Basic Shaft Bearingless Motors." Applied Mechanics and Materials 275-277 (January 2013): 2451–54. http://dx.doi.org/10.4028/www.scientific.net/amm.275-277.2451.

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A dynamic coupling model of the bearingless motor is established. This test does some simulations of motor displacement, no load speed and tracking accuracy under certain performance indicators. Analysis and simulation results show that the system has a control strategy of high precision as well as good dynamic and static performance.

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Qi, Lin, Yong Qiang Zhu, Zhi Yu Wang, and Chun Peng Fu. "Modeling for Lithium Iron Phosphate Battery and its Simulation in PSCAD." Applied Mechanics and Materials 331 (July 2013): 250–53. http://dx.doi.org/10.4028/www.scientific.net/amm.331.250.

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This paper proposes an improved dynamic model of lithium iron phosphate battery, and shows the simulation results. The method takes into account the nonlinear characteristics of the battery charging and discharging, and changes the variation of battery resistance into that of voltage, which makes the simulation circuit simpler and easier to be implemented. Simulations examine the time-changing characteristics of the state of charge (SOC), depth of discharge and the current/voltage in the charge/discharge processes, as well as the relationship between voltage and SOC. The model has correctively shown the dynamic characteristics of lithium iron phosphate battery in our simulations.

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Yang, Jing, Lingtao Yu, Lan Wang, Zhengyu Wang, and Wenjie Wang. "Dynamic modeling and analysis of the instrument arm based on the physical properties of soft tissues." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 232, no. 12 (2017): 2185–99. http://dx.doi.org/10.1177/0954406217715661.

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Surgical robot is a hotspot problem of the current research. This paper presents the dynamical analysis of an instrument arm for minimally invasive surgical robot. Firstly, the study presents a general dynamics modeling method, by which a dynamical model of the instrument arm is established and verified by simulation, then a general force of the trocar point is considered and related analysis is performed. Considering the diversity of the reaction force, one-dimensional force is added separately at the operating point and some simulations are performed based on the dynamic model. Secondly, mechanical characterization of soft tissues is researched based on the indentation experiments, where the constitutive models for compression and relaxation are derived and added to the dynamical model to establish a complete dynamic model with the property of soft tissues. Lastly, the trocar force is analyzed in detail where the instrument arm is found to be sensitive to the tiny force based on the simulation results, and then a force sensing strategy of contact force on soft tissues is presented. Comprehensively, dynamical analysis for the instrument arm will provide an important basis for its control.

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Blanchette, Carl, Maxime Boisvert, Nicolas Joubert, Denis Rancourt, and Alain Desrochers. "Dynamic input loads evaluation of a recreational vehicle frame using multibody dynamics hybrid modeling validated with experimental and full analytical modeling data." Advances in Mechanical Engineering 13, no. 8 (2021): 168781402110346. http://dx.doi.org/10.1177/16878140211034608.

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Knowledge of frame loads at the limits of the intended driving conditions is important during the design process of a vehicle structure. Yet, retrieving these loads is not trivial as the load path between the road and the frame mounting point is complex. Fortunately, recent studies have shown that multibody dynamic (MBD) simulations could be a powerful tool to estimate these loads. Two main categories of MBD simulations exist. Firstly, full analytical simulations, which have received great attention in the literature, are run in a virtual environment using a tire model and a virtual road. Secondly, hybrid simulations, also named semi analytical, uses experimental data from Wheel Force Transducers and Inertial Measurement Units to replace the road and tire models. It is still unclear how trustworthy semi analytical simulations are for frame load evaluation. Both methods were tested for three loads cases. It was found that semi analytical simulations were slightly better in predicting vehicle dynamic and frame loads than the full analytical simulations for frequencies under the MF-Tyre model valid frequency range (8 Hz) with accuracy levels over 90%. For faster dynamic maneuvers, the prediction accuracy was lower, in the 50%–80% range, with semi analytical simulations showing better results.

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Huang, Su Hai. "Modeling and Simulation of a Switchable Chaotic System with Fractional Order." Applied Mechanics and Materials 214 (November 2012): 935–38. http://dx.doi.org/10.4028/www.scientific.net/amm.214.935.

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A new three-dimensional autonomous chaotic system is constructed. Some basic dynamical characteristics of this system with integer order are studied. The switchable chaotic system is constitutive of two subsystems. The dynamic characteristics of the fractional-order switchable system varying with the differential operator orders with fixed parameter are analyzed. Numerical simulations on the dynamics of new system with fractional-order have been carried out.

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Djitog, Ignace, Hamzat Olanrewaju Aliyu, and Mamadou Kaba Traoré. "Multi-Perspective Modeling of Healthcare Systems." International Journal of Privacy and Health Information Management 5, no. 2 (2017): 1–20. http://dx.doi.org/10.4018/ijphim.2017070101.

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This paper presents a multi-perspective approach to Modeling and Simulation (M&S) of Healthcare Systems (HS) such that different perspectives are defined and integrated together. The interactions between the isolated perspectives are done through dynamic update of models output-to-parameter integration during concurrent simulations. Most often, simulation-based studies of HS in the literature focus on specific problem like allocation of resources, disease propagation, and population dynamics that are studied with constant parameters from their respective experimental frames throughout the simulation. The proposed idea provides a closer representation of the real situation and helps to capture the interactions between seemingly independent concerns - and the effects of such interactions - in simulation results. The article provides a DEVS (Discrete Event System Specification)-based formalization of the loose integration of the different perspectives, an Object-Oriented framework for its realization and a case study as illustration and proof of concept.

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Tian, Fu Yang, Yu Dao Li, Zhen Wang, and Fa De Li. "Efficient Recursive Dynamics and Real Time Simulation of Flexible Space Robots System." Advanced Materials Research 842 (November 2013): 546–52. http://dx.doi.org/10.4028/www.scientific.net/amr.842.546.

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As space robots gain more and more importance in space operations, it was becoming imperative to understand their distinctive dynamics. The dynamics model of the space flexible robots is very complex, and the differential equation derived from dynamics was solved difficultly and slowly. In this paper the efficient recursive O(n) dynamics algorithm of space flexible robots systems with rigid base and flexible manipulators was discussed, and the fast efficient integration method was used to solve this dynamics equation for real time simulation. Simulations results show that the dynamic modeling and fast efficient numerical integration techniques of flexible space robot proposed in this paper are very useful. Keyword: space robots;efficient dynamic; recursive; real time simulation

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Zayn, Afta Ramadhan, Fatwa Ramdani, and Fitra Abdurrachman Bachtiar. "Agent-based Modeling and Simulation for Evacuation of Landslides Natural Disaster." Journal of Information Technology and Computer Science 5, no. 2 (2020): 194. http://dx.doi.org/10.25126/jitecs.202052172.

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Landslides are natural disasters that pose a threat which is quite high in the area of Batu, East Java, Indonesia. The occurrence of landslides has a negative impact on environmental damage and even fatalities. These impacts can arise due to a lack of planning in disaster management preparedness. Therefore better planning is needed to minimize the negative impacts that arise. Improvement of planning can be done by conducting evacuation simulations. However, the existing evacuation simulation is still static with one scenario that is done repeatedly. Therefore, a more dynamic evacuation simulation is needed to represent the various parties involved in it and to apply various scenarios. Such dynamic simulations can be facilitated using agent technology. Agents can describe autonomous behaviour and can communicate in their environment to achieve a goal. Apply the capabilities of these agents by modelling and simulating the evacuation process can provide an illustration for a more dynamic process of landslide evacuation. This research presents an agent-based landslide evacuation model and the simulation results from this model. The results are concerned that, by using agent technology can apply simulations with various conditions. So with these results can be used as a reference in the handling of natural disasters that occur landslides.

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Deniz, Fatih, M. Nedim Alpdemir, Ahmet Kara, and Halit Oğuztüzün. "Supporting dynamic simulations with Simulation Modeling Architecture (SiMA): a Discrete Event System Specification-based modeling and simulation framework." SIMULATION 88, no. 6 (2012): 707–30. http://dx.doi.org/10.1177/0037549711428233.

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De Coninck, Stijn, Jeroen Smis, Jan Victor, Patrick De Baets, and Matthias Verstraete. "Computational modeling of a dynamic knee simulator." International Journal Sustainable Construction & Design 6, no. 2 (2015): 8. http://dx.doi.org/10.21825/scad.v6i2.1124.

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Knee replacement surgery has made a huge evolution during the past decades. For further improvements of knee arthroplasty, dynamic knee simulators are used for fully instrumented ex-vivo tests. This paper provides a closer look at the validation of the rig. Therefore, a hinge model is constructed, resulting in an unambiguous evaluating method. The actual position of the ankle and the reaction forces at the ankle are measured and compared with the simulations. The results indicate an excellent agreement between the outcome of the numerical simulations and the measured values. The kinematics and kinetics of the rig are accordingly considered as validated. In the future, the behaviour of a more realistic knee representation will be evaluated.

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Hoshiar, Ali Kafash, Hamed Raeisi Fard, Mohamad Mehdi Kheirikhah, and Hafez Raeisi Fard. "Modeling and Simulation of Nano Structures Based on Molecular Dynamics." Applied Mechanics and Materials 110-116 (October 2011): 1841–48. http://dx.doi.org/10.4028/www.scientific.net/amm.110-116.1841.

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As our knowledge about Nano grows we can apply Nano Technology in all fields of Science and Engineering. Molecular simulation can be used to simulate the manufacturing process in nano scale. In this paper, simulations in nano scale were investigated in two main reasons: 1- Morphology in Nano-Micro, 2-Simulation based on molecular dynamics. The basic and main aspects of both methods were explored and also a Matlab algorithm will be suggested to modeling the structure and dynamic in nano scale. First, some pieces in cylindrical and cubic forms were simulated and the effects of thermal treatment in different temperatures were investigated in light of this simulation. Second, a model based on molecular dynamics in 2D was developed to find out the effects of force exerted to AFM..

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Tuzhyk, Kateryna, Edyta Hewelke, and Piotr Hewelke. "Dynamic simulation of sustainable farm development scenarios using cognitive modeling." Annals of Warsaw University of Life Sciences – SGGW. Land Reclamation 49, no. 1 (2017): 43–53. http://dx.doi.org/10.1515/sggw-2017-0004.

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Abstract Dynamic simulation of sustainable farm development scenarios using cognitive modeling. The paper presents a dynamic simulation system of sustainable development scenarios on farms using cognitive modeling. The system incorporates relevant variables which affect the sustainable development of farms. Its user provides answers to strategic issues connected with the level of farm sustainability over a long-term perspective of dynamic development. The work contains a description of the model structure as well as the results of simulations carried out on 16 farms in northern Ukraine. The results show that the process of sustainability is based mainly on the potential for innovation in agricultural production and biodiversity. The user is able to simulate various scenarios for the sustainable development of a farm and visualize the influence of factors on the economic and social situation, as well as on environmental aspects. Upon carrying out a series of simulations, it was determined that the development of farms characterized by sustainable development is based on additional profit, which serves as the main motivation for transforming a conventional farm into a sustainable one. Nevertheless, additional profit is not the only driving force in the system of sustainable development. The standard of living, market condition, and legal regulations as well as government support also play a significant motivational role.

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Colella, Vanessa. "Participatory Simulations: Building Collaborative Understanding Through Immersive Dynamic Modeling." Journal of the Learning Sciences 9, no. 4 (2000): 471–500. http://dx.doi.org/10.1207/s15327809jls0904_4.

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Léger, Mathieu, and John McPhee. "Selection of modeling coordinates for forward dynamic multibody simulations." Multibody System Dynamics 18, no. 2 (2007): 277–97. http://dx.doi.org/10.1007/s11044-007-9083-1.

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Jayarathna, Sanoja A., Bernt Lie, and Morten C. Melaaen. "Amine based CO2 capture plant: Dynamic modeling and simulations." International Journal of Greenhouse Gas Control 14 (May 2013): 282–90. http://dx.doi.org/10.1016/j.ijggc.2013.01.028.

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Tuohineva, Terho, Ilkka Väisänen, Antti Mäntylä, Teemu Kuivaniemi, Mauri Haataja, and Tero Frondelius. "Benchmarking of two flexible multibody dynamic simulation software in engine simulations." Rakenteiden Mekaniikka 51, no. 2 (2018): 32–48. http://dx.doi.org/10.23998/rm.69961.

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In this paper, two different commercial multibody dynamic (MBD) simulation software cases are studied. Due to the restrictions determined in the conditions of contract, the names of the software are not revealed, instead being called Software S and Software E. The central purpose of this research was to investigate the abilities of Software S in the simulation of a large engine, as a part of the strength analysis process. The abilities were studied by comparing the program with another, here called Software E, which is designed primarily for engine simulations. The capabilities of Software E have been proven after years of usage at Wärtsilä, resulting in its essential role in the strength analysis process today. The aim was to find the shortcomings and restrictions of Software S but also advantages it could bring to the strength analysis process for Wärtsilä. Similar simulation models were also built using both programs during this research. A 16-cylinder V-engine was selected as the subject because of its size in order to obtain further information about the behavior of the program when working with extensive model files. The components of the engine were flexible and were reduced FE models, also called super elements. The forces and contact situations that occur inside the engine were modeled using elements provided by the MBD programs. Different levels of detail of the modeling elements were used to obtain information about the flexibility of the program. The results obtained from time integrations were compared to ensure the similarity of both modeling elements used. Also, this paper reports the calculation times. In addition, a small-scale study was performed for Software S to clarify the effect of the modes used in time integrations towards results accuracy and calculation times. Simulation models were built successfully in both programs, and the results obtained correlated with each other on an adequate level. Significant differences appeared in the features and usability of the programs in general. The GUI of Software S is advanced and user-friendly, whereas Software E is not focused on these features. On the other hand, the modeling element library of Software E covers all of the required features related to large engine simulations, some of which Software S is lacking. This work can be used in assistance when considering buying new software for a company as well as when investigating new development areas that could be improved with new software.

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Wang, Chao, and Jian Wang. "Risk-Field Based Modeling for Pedestrian Emergency Evacuation Combined with Alternative Route Strategy." Mathematical Problems in Engineering 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/3405619.

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For the past decades, with the frequent occurrence of emergencies, such as stampede, fire, and terrorist attack, the urgent requirements of developing realistic evacuation models to describe pedestrian and disaster dynamics are put forward. In this paper, an extended floor-field (FF) model combined with risk factors is presented for emergency evacuation. A novel dynamic rerouting mechanism is designed to elucidate the exit choice behavior of evacuees, and meanwhile, a recommended dynamic risk-field model is fully explored to deal with dynamical features of disaster. The proposed model is validated through numerical simulations with specific room structures. The effects of model parameters on evacuation efficiency and death toll are analyzed in detail. Simulation results show that the proposed model is effective and has a positive influence on evacuees’ exit choice behavior, and the death toll is closely related to the perceived information obtained by evacuee, such as the crowd density during the evacuation process.

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Shala, Ahmet, and Xhevahir Bajrami. "Dynamic Modeling and Analysis of Propulsion effect of 3 DoF robot." International Journal of Business & Technology 1, no. 2 (2013): 30–38. http://dx.doi.org/10.33107/ijbte.2013.1.2.03.

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Dynamical Modeling of robots is commonly first important step of Modeling, Analysis and Control of robotic systems. This paper is focused on using Denavit-Hartenberg (DH) convention for kinematics and Newton- Euler Formulations for dynamic modeling of 3 DoF - Degree of Freedom of 3D robot. The process of deriving of dynamical model is done using Software Maple. Simulations are done using Matlab/Simulink for analysis of propulsion effect under Earth gravity when First Link rotates with 1000 rpm, second Link can move free in vertical direction and Third Link can rotates free around their rotations axle. Simulations results shows very good propulsion of proposed 3 DoF robot. Results are verified-compared with constructed model of 3 DoF robot using Working Model 3D Software.

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Dai, Liangcheng, Maoru Chi, Hongxing Gao, and Jianfeng Sun. "An Investigation into the Modeling Methodology of the Coil Spring." Shock and Vibration 2020 (June 24, 2020): 1–13. http://dx.doi.org/10.1155/2020/8814332.

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The coil spring is an important element in the suspension system of railway vehicles, and its structural vibration caused by the mass distribution can deteriorate the dynamic performance of the vehicle. However, the coil spring is usually modelled as a simple linear force element without considering the dynamic characteristics in multibody dynamic simulations of railway vehicles. To integrate the dynamic characteristics of the coil spring into the simulation, three equivalent dynamic models of the coil spring are established by treating the coil spring as multimass spring series, Timoshenko beam, and flexible spring, respectively. The frequency-sweep method is applied to obtain the dynamic response of the proposed models of coil spring, and the accuracy of the models’ results has been compared and verified by the laboratory test. Results show that all of these three equivalent models can reflect the influence of the spring mass distribution on its dynamic responses. Compared with the mass-spring series and beam element equivalent models, the flexible spring model can better reflect the dynamic stiffness and stress of the coil spring changing with the exciting frequency. Thus, the flexible spring model proposed in this paper is more applicable to railway vehicle system dynamics and the fatigue analysis.

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Song, Yanyan, Boyan Chang, Guoguang Jin, Zhan Wei, and Bo Li. "An Approach for the Impact Dynamic Modeling and Simulation of Planar Constrained Metamorphic Mechanism." Shock and Vibration 2020 (August 5, 2020): 1–18. http://dx.doi.org/10.1155/2020/8837838.

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This paper studied the impact dynamic modeling of the planar constrained metamorphic mechanism (PCMM) during configuration transformation. Based on the dynamic theory of the multi-rigid-body system and the coefficient of restitution equation, a new method for dynamic modeling of PCMM considering impact motions generated by configuration transformation is presented, which can be treated as a theoretical foundation for performance design and dynamic control. Firstly, the topology theory based on the impact motion can be classified as the stable impact motion and the mobile impact motion, which is the prerequisite for dynamic modeling and simulation. Secondly, the stable and mobile impact dynamic models for PCMM are established according to the dynamic theory of the multi-rigid-body system. Then, using these models, the corresponding impulse solving models are deduced combining with the coefficient of restitution equation. Finally, the examples of the stable impact motion and the mobile impact motion are respectively given, and the configuration-complete dynamic simulations are carried out. By comparing with the dynamic models without considering the impact motion, the dynamic characteristics of PCMM are analyzed. The theory and method proposed in this paper can be also applied in general planar robotic systems to deal with the problem of internal collision dynamics.

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Feng, Ruoyu, Peng Zhang, Junfeng Li, and Hexi Baoyin. "Kinetic and Dynamic Modeling of Single ActuatorWave-Like Robot." Robotica 37, no. 11 (2019): 1971–86. http://dx.doi.org/10.1017/s0263574719000389.

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SummaryIn this study, the kinematics and dynamics of a single actuator wave (SAW)-like robot are explored. Comprising a helical spine and links, SAW has the potential for miniaturization. A kinematic model for SAW is firstly established, and the dynamic equation of motion is derived based on Kane’s method. For validation, the motion of SAW is simulated using both MATLAB and ADAMS, and the comparison of results demonstrates the effectiveness of the theoretical models. Then the inverse dynamic analysis is performed to reveal the power consumption. Finally, robot prototypes are developed and tested to confirm the robot velocity predicted by simulations.

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Ball, GL, and DP Guertin. "Improved Fire Growth Modeling." International Journal of Wildland Fire 2, no. 2 (1992): 47. http://dx.doi.org/10.1071/wf9920047.

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Recent developments in the use of GIs for spatial dynamic modeling has resulted in improved fire growth simulations. This paper examines previous growth models and some of their weaknesses. We then define what would be required to handle the growth of surface fire within a raster based GIS program. The paper discusses the requirements for the algorithm needed to model fire growth and how this algorithm is implemented using the PROMAP GIS modeling extensions. Examples are given of fire growth simulation using predefined conditions. The need for further testing of actual fires is discussed.

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Kmiecik, Sebastian, Maksim Kouza, Aleksandra Badaczewska-Dawid, Andrzej Kloczkowski, and Andrzej Kolinski. "Modeling of Protein Structural Flexibility and Large-Scale Dynamics: Coarse-Grained Simulations and Elastic Network Models." International Journal of Molecular Sciences 19, no. 11 (2018): 3496. http://dx.doi.org/10.3390/ijms19113496.

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Fluctuations of protein three-dimensional structures and large-scale conformational transitions are crucial for the biological function of proteins and their complexes. Experimental studies of such phenomena remain very challenging and therefore molecular modeling can be a good alternative or a valuable supporting tool for the investigation of large molecular systems and long-time events. In this minireview, we present two alternative approaches to the coarse-grained (CG) modeling of dynamic properties of protein systems. We discuss two CG representations of polypeptide chains used for Monte Carlo dynamics simulations of protein local dynamics and conformational transitions, and highly simplified structure-based elastic network models of protein flexibility. In contrast to classical all-atom molecular dynamics, the modeling strategies discussed here allow the quite accurate modeling of much larger systems and longer-time dynamic phenomena. We briefly describe the main features of these models and outline some of their applications, including modeling of near-native structure fluctuations, sampling of large regions of the protein conformational space, or possible support for the structure prediction of large proteins and their complexes.

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Li, Jian Jia, and Xin Hua Zhao. "Dynamics Modeling and Simulation of Tracked Five DOF Mobile Manipulator." Advanced Materials Research 433-440 (January 2012): 4817–22. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.4817.

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The dynamical analysis for the tracked moving platform and the manipulator are established based on by Newton-Euler method and Dynamics model is respectively obtained, Moreover, Dynamic simulation is conducted, and reveals the input-output relation for the motion system from dynamical simulation, and plays a solid basic for the further study of dynamic modeling and motion control.

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Shiari, B., R. E. Miller, and D. D. Klug. "Multiscale modeling of solids at the nanoscale: dynamic approach." Canadian Journal of Physics 86, no. 2 (2008): 391–400. http://dx.doi.org/10.1139/p07-145.

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One major class of multiscale models directly couples a region described with full atomistic detail to a surrounding region modeled using continuum concepts and finite element methods. Here, the development of a new dynamic approach to such coupled atomistic-continuum models is discussed with insight into the key ideas and features, with emphasis on fundamental difficulties involved in dynamic multiscale models. Simulations of nanoindentation in single crystals are performed to demonstrate the power of the developed method in capturing both long-range dislocation plasticity and short-range atomistic phenomena during single or cyclic loading without the computational cost of full atomistic simulations. The effects of several process variables are investigated, including system temperature and rate of indentation. The deformation mechanisms and the surface evaluation that occur during a series of single and cyclic indentation simulations are discussed. PACS Nos.: 81.07.–b or 73.22.–f

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Fiamma, P. "ARCHITECTURAL LARGE CONSTRUCTED ENVIRONMENT. MODELING AND INTERACTION USING DYNAMIC SIMULATIONS." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XXXVIII-5/W16 (September 10, 2012): 141–48. http://dx.doi.org/10.5194/isprsarchives-xxxviii-5-w16-141-2011.

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Visconti, Igor F., Delberis A. Lima, Janaina Mirses C. de Sousa Costa, and Nobyle Rabello de B. C. Sobrinho. "Measurement-Based Load Modeling Using Transfer Functions for Dynamic Simulations." IEEE Transactions on Power Systems 29, no. 1 (2014): 111–20. http://dx.doi.org/10.1109/tpwrs.2013.2279759.

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de Ruijter, M. J., T. D. Blake, and J. De Coninck. "Dynamic Wetting Studied by Molecular Modeling Simulations of Droplet Spreading." Langmuir 15, no. 22 (1999): 7836–47. http://dx.doi.org/10.1021/la990171l.

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Dorigatti, M., O. Chiotti, and H. E. Salomone. "Modeling Dynamic Interactions in Supply Chains Using Agent-Based Simulations." Iberoamerican Journal of Industrial Engineering 5, no. 10 (2013): 158–71. http://dx.doi.org/10.13084/2175-8018.v05n10a12.

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Liu, Hao-Ran, Peng Gao, and Hang Ding. "Fluid–structure interaction involving dynamic wetting: 2D modeling and simulations." Journal of Computational Physics 348 (November 2017): 45–65. http://dx.doi.org/10.1016/j.jcp.2017.07.017.

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Morman, K. N., E. Nikolaidis, J. Rakowska, and S. Seth. "Modeling and Identification of Elastomeric Bearing Characteristics for Large-Scale Simulations." Journal of Dynamic Systems, Measurement, and Control 120, no. 1 (1998): 63–73. http://dx.doi.org/10.1115/1.2801323.

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A constitutive equation of the differential type is introduced to model the nonlinear viscoelastic response behavior of elastomeric bearings in large-scale system simulations for vibration assessment and component loads prediction. The model accounts for the nonlinear dependence of dynamic stiffness and damping on vibration amplitude commonly observed in the behavior of bearings made of particle-reinforced elastomers. A testing procedure for the identification of the model parameters from bearing component test data is described. The experimental and analytical results for predicting the behavior of four (4) different car bushings are presented. In an example application, the model is incorporated in an ADAMS simulation to study the dynamic behavior of a car rear suspension.

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Kowalik, Rafał, and Emil Sadowski. "Mathematical modeling and analysis of dynamic phenomena turnout rail." Transportation Overview - Przeglad Komunikacyjny 2017, no. 10 (2017): 36–44. http://dx.doi.org/10.35117/a_eng_17_10_05.

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The article presents the results of simulations carried out for the developments on the railway junction in the instantaneous passage of a railway vehicle. The main focus lies on getting runs all three forces present in the area of the point of contact wheel-rail. Tests carried out for different vehicle speed rail-track. In addition, also presented mathematical models describing the motion of the train to pass through the railway track and discusses the mathematical considerations describing the deflection of the beam under the influence of rolling wheels on it. At the end shows the conclusions of the simulations.

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Dong, Wei Guang, Hong Guang Wang, and Yong Jiang. "Dynamic Modeling and Simulation of a Novel Wall-Climbing Robot." Applied Mechanics and Materials 336-338 (July 2013): 1180–85. http://dx.doi.org/10.4028/www.scientific.net/amm.336-338.1180.

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The dynamic modeling and simulation of a novel wall-climbing robot is presented. For the novel biped-wheel hybrid locomotion mechanism of the robot, its locomotion modes and typical state of motion are analyzed. Based on the description of the robots pose, the dynamic model for two typical states of motion, point turning in a flat surface and transition between two intersecting surfaces, is established. The equation for calculating adhesion force when the robot moves on arbitrary inclined surfaces is derived from the dynamic model. Simulations for the adhesion force are implemented with three typical examples. The results show that the tilt angle of the attachment surface and the motion direction of the robot have great influence on the adhesion force.

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Fasoulas, John, and Michael Sfakiotakis. "Modeling and Grasp Stability Analysis for Object Manipulation by Soft Rolling Fingertips." International Journal of Humanoid Robotics 11, no. 03 (2014): 1450020. http://dx.doi.org/10.1142/s0219843614500200.

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This paper presents a general dynamic model that describes the two-dimensional grasp by two robotic fingers with soft fingertips. We derive the system's kinematics and dynamics by incorporating rolling constraints that depend on the deformation and on the rolling distance characteristics of the fingertips' material. We analyze the grasp stability at equilibrium, and conclude that the rolling properties of the fingertips can play an important role in grasp stability, especially when the width of the grasped object is small compared to the radius of the tips. Subsequently, a controller, which is based on the fingertips' rolling properties, is proposed for stable grasping concurrent with object orientation control. We evaluate the dynamic model under the proposed control law by simulations and experiments that make use of two different types of soft fingertip materials, through which it is confirmed that the dynamic model can successfully capture the effect of the fingertips' deformation and their rolling distance characteristics. Finally, we use the dynamic model to demonstrate by simulations the significance of the fingertips' rolling properties in grasping thin objects.

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Xu, Yaru, and Rong Liu. "Concise method to the dynamic modeling of climbing robot." Advances in Mechanical Engineering 9, no. 2 (2017): 168781401769167. http://dx.doi.org/10.1177/1687814017691670.

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With the aim of dynamic modeling of the climbing robot with dual-cavity structure and wheeled locomotion mechanism, a succinct and explicit equation of motion based on the Udwadia–Kalaba equation is established. The trajectory constraint of the climbing robot, which is regarded as the external constraint of the system, is integrated into the dynamic equation dexterously. A modified numerical method is considered to reduce the errors because the numerical results obtained by integrating the constrained dynamic equation yield the errors. The trajectories are almost coincident by comparing the modified numerical value and the theoretical value. The driving torques required to guarantee the climbing robot to move along the given trajectory are obtained explicitly, which overcomes the disadvantage of obtaining dynamical equation from traditional Lagrange equation by Lagrange multiplier. The simulations are performed to demonstrate that the dynamical equation established by this method with brevity and accuracy is in accordance with reality status.

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Lebo, Matthew J., and Taylor Grant. "Equation Balance and Dynamic Political Modeling." Political Analysis 24, no. 1 (2016): 69–82. http://dx.doi.org/10.1093/pan/mpv035.

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The papers in this symposium agree on several points. In this article, we sort through some remaining areas of disagreement and discuss some of the practical issues of time series modeling we think deserve further explanation. In particular, we have five points: (1) clarifying our stance on the general error correction model in light of the comments in this issue; (2) clarifying equation balance and discussing how bounded series affects our thinking about stationarity, balance, and modeling choices; (3) answering lingering questions about our Monte Carlo simulations and exploring potential problems in the inferences drawn from long-run multipliers; (4) reviewing and defending fractional integration methods in light of the questions raised in this symposium and elsewhere; and (5) providing a short practical guide to estimating a multivariate autoregressive fractionally integrated moving average model with or without an error correction term.

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Davoodi, Rahman, and Gerald E. Loeb. "A Software Tool for Faster Development of Complex Models of Musculoskeletal Systems and Sensorimotor Controllers in SimulinkTM." Journal of Applied Biomechanics 18, no. 4 (2002): 357–65. http://dx.doi.org/10.1123/jab.18.4.357.

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Computer models of the neuromusculoskeletal systems can be used to study different aspects of movement and its control in humans and animals. SIMM with Dynamics Pipeline (Musculographics Inc., Chicago) and SD-Fast (Symbolic Dynamics Inc., Mountain View, CA) are software packages commonly used for graphic and dynamic simulation of movement in musculoskeletal systems. Building dynamic models with SIMM requires substantial C programming, however, which limits its use. We have developed Musculoskeletal Modeling in Simulink (MMS) software to convert the SIMM musculoskeletal and kinetics models to Simulink (Mathworks Inc., Natick, MA) blocks. In addition, MMS removes SIMM’s run-time constraints so that the resulting blocks can be used in simulations of closed-loop sensorimotor control systems.

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Gray, Jeff, and Bernhard Rumpe. "Modeling dynamic structures." Software and Systems Modeling 19, no. 3 (2020): 527–28. http://dx.doi.org/10.1007/s10270-020-00793-7.

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Cooke, Joseph M., Michael J. Zyda, David R. Pratt, and Robert B. McGhee. "NPSNET: Flight Simulation Dynamic Modeling Using Quaternions." Presence: Teleoperators and Virtual Environments 1, no. 4 (1992): 404–20. http://dx.doi.org/10.1162/pres.1992.1.4.404.

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The Naval Postgraduate School (NPS) has actively explored the design and implementation of networked, real time, three-dimensional battlefield simulations on low-cost, commercially available graphics workstations. The most recent system, NPSNET, has improved in functionality to such an extent that it is considered a low-cost version of the Defense Advanced Research Project Agency's (DARPA) SIMNET system. To reach that level, it was necessary to economize in certain areas of the code so that real time performance occurred at an acceptable level. One of those areas was in aircraft dynamics. However, with “off-the-shelf” computers becoming faster and cheaper, real-time and realistic dynamics are no longer an expensive option. Realistic behavior can now be enhanced through the incorporation of an aerodynamic model. To accomplish this task, a prototype flight simulator was built that is capable of simulating numerous types of aircraft simultaneously within a virtual world. Besides being easily incorporated into NPSNET, such a simulator also provides the base functionality for the creation of a general purpose aerodynamic simulator that is particularly useful to aerodynamics students for graphically analyzing differing aircraft's stability and control characteristics. This system is designed for use on a Silicon Graphics workstation and uses the GL libraries. A key feature of the simulator is the use of quaternions for aircraft orientation representation to avoid singularities and high data rates associated with the more common Euler angle representation of orientation.

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Dolfin, Marina, and Mirosław Lachowicz. "Modeling altruism and selfishness in welfare dynamics: The role of nonlinear interactions." Mathematical Models and Methods in Applied Sciences 24, no. 12 (2014): 2361–81. http://dx.doi.org/10.1142/s0218202514500237.

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This paper deals with the modeling, qualitative and numerical analysis, of welfare dynamics in societies viewed as complex evolutive systems subject to different policies of wealth distribution. A nonlinear model of wealth distribution is presented. The state of a population is modeled by a probability distribution over wealth classes and the dynamic of interaction is parameterized by a threshold, whose dynamics depends on an internal competition related to the wealth distribution. Therefore, the model is a system of equations in which the threshold is one of the dynamic variables. The approach contains the whole path from modeling to simulations, through a qualitative analysis of the initial value problem.

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Kim, Moojin, Wonkyu Moon, Daesung Bae, and Ilhan Park. "Dynamic simulations of electromechanical robotic systems driven by DC motors." Robotica 22, no. 5 (2004): 523–31. http://dx.doi.org/10.1017/s0263574704000177.

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When modeling the dynamics of robotic systems containing electric motors, the force generated by the motor is generally considered only as an applied torque or force that is independent of mechanical state variables such as velocity. Due to the electromechanical coupling effects in the motors, this approach leads engineers working on a robotic system to designing faulty controllers. In this paper, we propose a dynamics analysis model in which DC motor dynamics are embedded into a mechanical dynamics model such that the electromechanical coupling effects are included in the overall model. A model for the DC motor is developed based on its equivalent circuit model and incorporated into the generalized recursive dynamics formula previously developed by our group. The resulting dynamic numerical simulation program provides an effective and realistic approach for analyzing the electromechanical dynamics of robotic systems driven by DC motors. The developed numerical simulation tool is evaluated by applying to an industrial robot and a flexible antenna system driven by DC motors for a satellite.

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Rauscher, Sara A., Todd D. Ringler, William C. Skamarock, and Arthur A. Mirin. "Exploring a Global Multiresolution Modeling Approach Using Aquaplanet Simulations*." Journal of Climate 26, no. 8 (2013): 2432–52. http://dx.doi.org/10.1175/jcli-d-12-00154.1.

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Abstract Results from aquaplanet experiments performed using the Model for Prediction across Scales (MPAS) hydrostatic dynamical core implemented within the Department of Energy (DOE)–NCAR Community Atmosphere Model (CAM) are presented. MPAS is an unstructured-grid approach to climate system modeling that supports both quasi-uniform and variable-resolution meshing of the sphere based on conforming grids. Using quasi-uniform simulations at resolutions of 30, 60, 120, and 240 km, the authors evaluate the performance of CAM-MPAS via its kinetic energy spectra, general circulation, and precipitation characteristics. By analyzing an additional variable-resolution simulation with grid spacing that varies from 30 km in a spherical, continental-sized equatorial region to 240 km elsewhere, the CAM-MPAS’s potential for use as a regional climate simulation tool is explored. Similar to other quasi-uniform aquaplanet simulations, tropical precipitation increases with resolution, indicating the resolution sensitivity of the physical parameterizations. Comparison with the finite volume (FV) dynamical core suggests a weaker tropical circulation in the CAM-MPAS simulations, which is evident in reduced tropical precipitation and a weaker Hadley circulation. In the variable-resolution simulation, the kinetic energy spectrum within the high-resolution region closely resembles the quasi-uniform 30-km simulation, indicating a robust simulation of the fluid dynamics. As suggested by the quasi-uniform simulations, the CAM4 physics behave differently in the high and low resolution regions. A positive precipitation anomaly occurs on the western edge of the high-resolution region, exciting a Gill-type response; this zonal asymmetry represents the errors incurred in a variable resolution setting. When paired with a multiresolution mesh, the aquaplanet test case offers an exceptional opportunity to examine the response of physical parameterizations to grid resolution.

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Gao, Shu Hua, Rui Fan, and Dan Wang. "Dynamic Modeling and Model-Based Force Control of a 3-DOF Translational Parallel Robot." Advanced Materials Research 1006-1007 (August 2014): 609–17. http://dx.doi.org/10.4028/www.scientific.net/amr.1006-1007.609.

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A 3-axis parallel loading mechanism, which works as a multi-axis load simulator, is proposed for reliability test of multi-axis CNC machine tools by exerting specific load spectrums on the spindle. To achieve efficient loading force control, dynamic model of the 3-DOF translational parallel robot is derived via the virtual work principle and is embedded into the control strategy to build a model-based control scheme. A mass distribution factor is introduced and the rotating inertia of the limbs is neglected to simplify the dynamics equations for better real-time control performance. This simplification method is verified by comparison with the complete dynamics model. Then the simplified dynamic model is integrated with a PI (proportional–integral) controller with feedforward to control the moving platform’s output force in the task space and this control strategy is verified through co-simulations with MATLAB/Simulink and ADAMS. Simulation results show that the proposed model-based PI controller is effective to control the three-dimensional output force of the 3-DOF translational parallel robot.

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Otte, Tanya L. "The Impact of Nudging in the Meteorological Model for Retrospective Air Quality Simulations. Part II: Evaluating Collocated Meteorological and Air Quality Observations." Journal of Applied Meteorology and Climatology 47, no. 7 (2008): 1868–87. http://dx.doi.org/10.1175/2007jamc1791.1.

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Abstract For air quality modeling, it is important that the meteorological fields that are derived from meteorological models reflect the best characterization of the atmosphere. It is well known that the accuracy and overall representation of the modeled meteorological fields can be improved for retrospective simulations by creating dynamic analyses in which Newtonian relaxation, or “nudging,” is used throughout the simulation period. This article, the second of two parts, provides additional insight into the value of using nudging-based data assimilation for dynamic analysis in the meteorological fields for air quality modeling. Meteorological simulations are generated by the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5) using both the traditional dynamic analysis approach and forecasts for a summertime period. The resultant meteorological fields are then used for emissions processing and air quality simulations using the Community Multiscale Air Quality Modeling System (CMAQ). The predictions of surface and near-surface meteorological fields and ozone are compared with a small network of collocated meteorological and air quality observations. Comparisons of 2-m temperature, 10-m wind speed, and surface shortwave radiation show a significant degradation over time when nudging is not used, whereas the dynamic analyses maintain consistent statistical scores over time for those fields. Using nudging in MM5 to generate dynamic analyses, on average, leads to a CMAQ simulation of hourly ozone with smaller error. Domainwide error patterns in specific meteorological fields do not directly or systematically translate into error patterns in ozone prediction at these sites, regardless of whether nudging is used in MM5, but large broad-scale errors in shortwave radiation prediction by MM5 directly affect ozone prediction by CMAQ at specific sites.

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