Articles de revues sur le sujet « Nonlinear dynamic system modeling and control »
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Baranyi, P., et A. R. Varkonyi-Koczy. « TP Transformation Based Dynamic System Modeling for Nonlinear Control ». IEEE Transactions on Instrumentation and Measurement 54, no 6 (décembre 2005) : 2191–203. http://dx.doi.org/10.1109/tim.2005.858576.
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Dantas, Tarcísio Soares Siqueira, Ivan Carlos Franco, Ana Maria Frattini Fileti et Flávio Vasconcelos da Silva. « Nonlinear System Identification of a Refrigeration System ». International Journal of Air-Conditioning and Refrigeration 24, no 04 (décembre 2016) : 1650024. http://dx.doi.org/10.1142/s2010132516500243.
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Applications of advanced control algorithms are important in the refrigeration field to achieve low-energy costs and accurate set-point tracking. However, the designing and tuning of control systems depend on dynamic mathematical models. Approaches like analytical modeling can be time-consuming because they usually lead to a large number of differential equations with unknown parameters. In this work, the application of system identification with the fast recursive orthogonal least square (FROLS) algorithm is proposed as an alternative to analytical modeling to develop a process dynamic model. The evaporating temperature (EVT), condensing temperature (CDT) and useful superheat (USH) are the outputs of interest for this system; covariance analysis of the candidate inputs shows that the model should be single-input–single-output (SISO). Good simulation results are obtained with two different validation data, with average output errors of 0.0343 (EVT model), 0.0079 (CDT model) and 0.1578 (USH model) for one of the datasets, showing that this algorithm is a valid alternative for modeling refrigeration systems.
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Song, H., R. Fraanje, G. Schitter, G. Vdovin et M. Verhaegen. « Modeling and Control of a Nonlinear Dynamic Adaptive Optics System ». IFAC Proceedings Volumes 43, no 18 (2010) : 299–305. http://dx.doi.org/10.3182/20100913-3-us-2015.00079.
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LEI, S., et A. TURAN. « NONLINEAR/CHAOTIC MODELING AND CONTROL OF COMBUSTION INSTABILITIES ». International Journal of Bifurcation and Chaos 20, no 04 (avril 2010) : 1245–54. http://dx.doi.org/10.1142/s0218127410026447.
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A discrete dynamic model accounting for both combustion and vaporization processes is proposed. In terms of different bifurcation parameters relevant to either combustion or evaporation, various bifurcation diagrams are presented. Furthermore, the corresponding Lyapunov exponent is calculated and employed to analyze the stability of the particular dynamic system. The study indicates conclusively that the evaporation process has a significant impact on the intensity and nonlinear behavior of the system of interest, vis-à-vis a model accounting for only the gaseous combustion process. Moreover, a minimum entropy control method is employed to control the chaotic behavior inherent to the system of interest. This algorithm is intended to be implemented for control of combustion instability numerically and experimentally to provide a basis for some of the control methodologies employed in the literature.
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Pandey, Dev Ras. « Dynamic Modeling of Nonlinear Systems in Cyber-Physical Environments ». Communications on Applied Nonlinear Analysis 30, no 2 (1 décembre 2023) : 40–55. http://dx.doi.org/10.52783/cana.v30.272.
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Complex behavior understanding and prediction relies on dynamic modeling of nonlinear systems in cyber-physical contexts. Critical for improving control systems, anticipating maintenance needs, and bolstering resilience, it permits accurate portrayal of complex interactions between cyber and physical components. Guaranteeing efficient and adaptable performance in networked ecosystems is made possible by this insight. Dynamic modeling of nonlinear systems (DM-NS) in cyber-physical settings has a number of challenges, such as the need to accurately depict complex interdependencies, accommodate changes in real-time, and reduce uncertainty. Advanced modeling techniques are required to capture the subtle behaviours and maintain the accuracy of the models while trying to balance the complicated interactions between physical and cyber components. A novel strategy is suggested to tackle these obstacles: Analysing Nonlinear Systems Cyber-Physical Modeling (ANSC-PM). By integrating complex mathematical models with adaptive learning algorithms, ANSC-PM is able to characterize nonlinear system behaviours, taking into account the dynamic interplay between cyber and physical components. To remain relevant as system dynamics change, the suggested method adjusts in real-time. Numerous disciplines find ANSC-PM useful, such as control system optimization, robotic predictive maintenance, and networked environment resilience enhancement. The effectiveness of ANSC-PM is determined by careful simulation analysis, which provides insight into its possible benefits in improving system performance, flexibility, and resilience in complex cyber-physical settings. Developing a thorough and flexible strategy that is adapted to the intricacies of cyber-physical systems, this research makes a substantial contribution to the progress of dynamic modeling approaches.
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Gevelber, M. A., M. Bufano et M. Toledo-Quin˜ones. « Dynamic Modeling Analysis for Control of Chemical Vapor Deposition ». Journal of Dynamic Systems, Measurement, and Control 120, no 2 (1 juin 1998) : 164–69. http://dx.doi.org/10.1115/1.2802405.
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A nonlinear dynamic model of the chemical vapor deposition (CVD) process has been developed to aid design of a closed-loop control system. A lumped control volume analysis is used to capture important mass and fluid transients and spatial affects, while a simplified single variable equation is used to represent the complex reaction chemistry. Steady-state experimental results and model predictions are compared and the control implications of the process dynamics are discussed.
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Annaswamy, A. M., et D. Seto. « Object Manipulation Using Compliant Fingerpads : Modeling and Control ». Journal of Dynamic Systems, Measurement, and Control 115, no 4 (1 décembre 1993) : 638–48. http://dx.doi.org/10.1115/1.2899191.
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Current industrial robots are often required to perform tasks requiring mechanical interactions with their environment. For tasks that require grasping and manipulation of unknown objects, it is crucial for the robot end-effector to be compliant to increase grasp stability and manipulability. The dynamic interactions that occur between such compliant end-effectors and deformable objects that are being manipulated can be described by a class of nonlinear systems. In this paper, we determine algorithms for grasping and manipulation of these objects by using adaptive feedback techniques. Methods for control and adaptive control of the underlying nonlinear system are described. It is shown that although standard geometric techniques for exact feedback linearization techniques are inadequate, yet globally stable adaptive control algorithms can be determined by making use of the stability characteristics of the underlying nonlinear dynamics.
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Tan, Yonghong, et Xinlong Zhao. « NEURAL MODELING AND CONTROL OF DYNAMIC SYSTEMS WITH HYSTERESIS ». Transactions of the Canadian Society for Mechanical Engineering 31, no 1 (mars 2007) : 127–41. http://dx.doi.org/10.1139/tcsme-2007-0008.
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A hysteretic operator is proposed to set up an expanded input space so as to transform the multi-valued mapping of hysteresis to a one-to-one mapping so that the neural networks can be applied to model of the behavior of hysteresis. Based on the proposed neural modeling strategy for hysteresis, a pseudo control scheme is developed to handle the control of nonlinear dynamic systems with hysteresis. A neural estimator is constructed to predict the system residual so that it avoids constructing the inverse model of hysteresis. Thus, the control strategy can be used for the case where the output of hysteresis is unmeasurable directly. Then, the corresponding adaptive control strategy is presented. The application of the novel modeling approach to hysteresis in a piezoelectric actuator is illustrated. Then a numerical example of using the proposed control strategy for a nonlinear system with hysteresis is presented.
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Liu, Ye Jiao, Zhi Chao Tian et Dong Mei Huang. « System Dynamics Model of Coalmine Safety Management ». Applied Mechanics and Materials 353-356 (août 2013) : 2381–84. http://dx.doi.org/10.4028/www.scientific.net/amm.353-356.2381.
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Based on the dynamic, nonlinear and feedback features of coalmine safety management control process, with the purpose of identifying the complex interdependence relationships of the various elements of coalmine safety management system, system dynamics (SD) is used as a tool to study coalmine safety management and control issues; to elaborate various elements related to safety benefit in the process of dynamic coalmine safety management and the relationships between them. The causal link between those factors and the systematic dynamics flow figure model are established by using the modeling and simulating software which is called VENSIM.
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Smolarik, Lukas, Dušan Mudrončík et Milan Strbo. « Modeling and Control of Compression System ». Applied Mechanics and Materials 693 (décembre 2014) : 110–16. http://dx.doi.org/10.4028/www.scientific.net/amm.693.110.
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Surge is a type of instability, that dramatically affects the operation and life of the turbocharger. There were analyzed the options for the control of surge of which were control designed for surge avoidance (method of minimizing the flow through the control valve). This algorithm is based on the logic of closure control valve at a constant speed regardless of the error. Besides of control were designed surge and control curves. To verify the solution was modeled and implemented nonlinear parametric model with downstream with control valve (Fink model) in Matlab. The simulation models are needed for physical systems, and develop good management strategy. Derivation of the compressor characteristic is presented. Dynamic model also includes two characteristics of valves describing mass flow.
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Rasmussen, Bryan P., et Andrew G. Alleyne. « Control-Oriented Modeling of Transcritical Vapor Compression Systems ». Journal of Dynamic Systems, Measurement, and Control 126, no 1 (1 mars 2004) : 54–64. http://dx.doi.org/10.1115/1.1648312.
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This paper presents a methodology for developing a low order dynamic model of a transcritical air-conditioning system, specifically suited for multivariable controller design. An 11th-order nonlinear dynamic model of the system is derived using first principles. Analysis indicates that the system exhibits multiple time scale behavior, and that model reduction is appropriate. Model reduction using singular perturbation techniques yields physical insight as to which physical phenomena are relatively fast/slow, and a 5th-order dynamic model appropriate for multivariable controller design. Although all results shown are for a transcritical cycle, the methodology presented can easily be extended to subcritical cycles.
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Yu, Yang, et Zengqiang Mi. « Dynamic Modeling and Control of Electromechanical Coupling for Mechanical Elastic Energy Storage System ». Journal of Applied Mathematics 2013 (2013) : 1–11. http://dx.doi.org/10.1155/2013/603063.
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The structural scheme of mechanical elastic energy storage (MEES) system served by permanent magnet synchronous motor (PMSM) and bidirectional converters is designed. The aim of the research is to model and control the complex electromechanical system. The mechanical device of the complex system is considered as a node in generalized coordinate system, the terse nonlinear dynamic model of electromechanical coupling for the electromechanical system is constructed through Lagrange-Maxwell energy method, and the detailed deduction of the mathematical model is presented in the paper. The theory of direct feedback linearization (DFL) is applied to decouple the nonlinear dynamic model and convert the developed model from nonlinear to linear. The optimal control theory is utilized to accomplish speed tracking control for the linearized system. The simulation results in three different cases show that the proposed nonlinear dynamic model of MEES system is correct; the designed algorithm has a better control performance in contrast with the conventional PI control.
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Ye, Qing, Ruochen Wang, Yinfeng Cai et Long Chen. « Research on modeling and compensation control strategy of automatic steering system ». Science Progress 103, no 1 (27 septembre 2019) : 003685041987502. http://dx.doi.org/10.1177/0036850419875027.
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A novel compensation control strategy is proposed to compensate for automatic steering system controller limitations in instability under nonlinear interference condition. In this article, the structure and mechanism of automatic steering system are briefly introduced at first. The nonlinear dynamic models of automatic steering system and vehicle are established, and the interference torque models of automatic steering system caused by different speed are then derived through the mechanism of tire structure. Simulations under different road conditions and different vehicle velocities are then used to validate the influence of nonlinear factors on the automatic steering system. Finally, the compensation controller is designed, and the effectiveness of designed controller has been verified by simulation results, in which the dynamic control effect and tracking accuracy of designed controller have been improved significantly. Finally, the novel controller is designed based on Simulink results, and test results reconfirm the partial performance of controller effectively.
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Taheri, Moein. « Nonlinear dynamic modeling and optimal motion analysis of two-link manipulators ». IAES International Journal of Robotics and Automation (IJRA) 5, no 1 (1 mars 2016) : 61. http://dx.doi.org/10.11591/ijra.v5i1.pp61-66.
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<p>Manipulators are used in various industrial applications to perform variant operations such as conveying payloads. Regarding to their applications, dynamic modeling and motion analysis of manipulators are known as important and appealing tasks. In this work, nonlinear dynamics and optimal motion analysis of two-link manipulators are investigated. To dynamic modeling of the system, the Lagrange principle is employed and nonlinear dynamic equations of the manipulator are presented in state-space form. Then, optimal motion analysis of the nonlinear system is developed based on optimal control theory. By means of optimal control theory, indirect solution of problem results in a two-point boundary value problem which can be solved numerically. Finally, in order to demonstrate the power and efficiency of method, a number of simulations are performed for a two-link manipulator which show applicability of proposed method.</p>
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Yan, Jun, Bo Li, Hai-Feng Ling, Hai-Song Chen et Mei-Jun Zhang. « Nonlinear State Space Modeling and System Identification for Electrohydraulic Control ». Mathematical Problems in Engineering 2013 (2013) : 1–9. http://dx.doi.org/10.1155/2013/973903.
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The paper deals with nonlinear modeling and identification of an electrohydraulic control system for improving its tracking performance. We build the nonlinear state space model for analyzing the highly nonlinear system and then develop a Hammerstein-Wiener (H-W) model which consists of a static input nonlinear block with two-segment polynomial nonlinearities, a linear time-invariant dynamic block, and a static output nonlinear block with single polynomial nonlinearity to describe it. We simplify the H-W model into a linear-in-parameters structure by using the key term separation principle and then use a modified recursive least square method with iterative estimation of internal variables to identify all the unknown parameters simultaneously. It is found that the proposed H-W model approximates the actual system better than the independent Hammerstein, Wiener, and ARX models. The prediction error of the H-W model is about 13%, 54%, and 58% less than the Hammerstein, Wiener, and ARX models, respectively.
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Cui, Tingqiong, Yinong Li, Chenglin Zan et Yuanchang Chen. « Dynamic Modeling and Analysis of Nonlinear Compound Planetary System ». Machines 10, no 1 (1 janvier 2022) : 31. http://dx.doi.org/10.3390/machines10010031.
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In the vehicle composite planetary gear transmission system, nonlinear excitations such as time-varying meshing stiffness, backlash and comprehensive error would lead to large vibration and noise, uneven load distribution, unstable operation and other problems. To address these issues, this work focuses on compound planetary gears and develops the bending-torsion coupling nonlinear dynamic model of the system based on the Lagrange equation. There are internal and external multi-source excitations applied to the system. This model is used to study the bending-torsion coupling meshing deformation relationship of each meshing pair along with the translational and torsional directions. The natural frequencies and vibration modal characteristics of the system are extracted from the model, and the influence of rotational inertia and meshing stiffness on the inherent characteristics of the system are studied. The coupling vibration characteristics of the system under operating condition are analyzed in terms of the inherent characteristics and time–frequency characteristics of the system. The simulation results exhibit that the planetary gear system has three modes. The change in natural frequency trajectory has two phenomena: modal transition and trajectory intersection. The main frequencies include engine rotating frequency, meshing frequency and its double frequency, and the rotation frequency and harmonic frequency of the engine have a great influence on the vibration response of the system. Finally, the virtual prototype of the composite planetary system is used to verify the accuracy of the established model from speed, inherent characteristics, meshing force and frequency composition.
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Wei, Wei, Hongchao Jian, Qingdong Yan, Xiaomei Luo et Xuhong Wu. « Nonlinear modeling and stability analysis of a pilot-operated valve-control hydraulic system ». Advances in Mechanical Engineering 10, no 11 (novembre 2018) : 168781401881066. http://dx.doi.org/10.1177/1687814018810660.
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A nonlinear dynamic model is developed to analyze the stability of a pilot-operated valve-control hydraulic system. The dynamic model includes motion of the valve spool and fluid dynamics in the system. Characteristics such as pressure flow across the valve port and orifices, pressure, and flow rate in valve chambers are taken into consideration. Bifurcation analysis is proposed and examined by numerical simulation results when the feedback orifice diameter changes. The effects of different system parameters such as pilot-operating pressure, spring stiffness, and overlap of inlet port on the stability border of the system are studied by two-dimensional bifurcation analyses. The study identifies that bifurcation can occur in the system and lead to sustained self-excited vibration with parameters in certain region of the parameter space. It suggests that the vibration can be effectively predicted and prevented by selecting system parameters from the asymptotic stable parameter region.
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Spong, M. W. « Modeling and Control of Elastic Joint Robots ». Journal of Dynamic Systems, Measurement, and Control 109, no 4 (1 décembre 1987) : 310–18. http://dx.doi.org/10.1115/1.3143860.
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In this paper we study the modeling and control of robot manipulators with elastic joints. We first derive a simple model to represent the dynamics of elastic joint manipulators. The model is derived under two assumptions regarding dynamic coupling between the actuators and the links, and is useful for cases where the elasticity in the joints is of greater significance than gyroscopic interactions between the motors and links. In the limit as the joint stiffness tends to infinity, our model reduces to the usual rigid model found in the literature, showing the reasonableness of our modeling assumptions. We show that our model is significantly more tractable with regard to controller design than previous nonlinear models that have been used to model elastic joint manipulators. Specifically, the nonlinear equations of motion that we derive are shown to be globally linearizable by diffeomorphic coordinate transformation and nonlinear static state feedback, a result that does not hold for previously derived models of elastic joint manipulators. We also detail an alternate approach to nonlinear control based on a singular perturbation formulation of the equations of motion and the concept of integral manifold. We show that by a suitable nonlinear feedback, the manifold in state space which describes the dynamics of the rigid manipulator, that is, the manipulator without joint elasticity, can be made invariant under solutions of the elastic joint system. The implications of this result for the control of elastic joint robots are discussed.
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Galvan-Perez, Daniel, Hugo Yañez-Badillo, Francisco Beltran-Carbajal, Ivan Rivas-Cambero, Antonio Favela-Contreras et Ruben Tapia-Olvera. « Neural Adaptive Robust Motion-Tracking Control for Robotic Manipulator Systems ». Actuators 11, no 9 (7 septembre 2022) : 255. http://dx.doi.org/10.3390/act11090255.
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This paper deals with the motion trajectory tracking control problem based on output feedback and artificial neural networks for anthropomorphic manipulator robots under disturbed operating scenarios. This class of manipulator robots constitutes nonlinear dynamic systems subjected to disturbance torques induced mainly by work payload. Parametric uncertainty and possible dynamic modeling errors stand for other kind of disturbances that can deteriorate the efficiency and robustness of the tracking of controlled nonlinear robotic system trajectories. In fact, the presence of unknown dynamic disturbances is unavoidable in industrial robotic engineering systems. Therefore, for high-precision applications, such as laser cutting, marking, or welding, effective control schemes should be designed to guarantee adequate motion profile tracking planned on this class of disturbed nonlinear robotic system. In this context, a new adaptive robust motion trajectory tracking control scheme based on output feedback and artificial neural networks of anthropomorphic manipulator robots is presented. Three-layer B-spline artificial neural networks and time-series modeling are properly exploited in the design of novel adaptive robust motion tracking controllers for robotic applications of laser manufacturing. In this way, dependency on detailed nonlinear mathematical modeling of robotic systems is considerably reduced, and real-time estimation of uncertain dynamic disturbances is not required. Furthermore, several cases studies to demonstrate the motion planning tracking control robustness for a class of MIMO nonlinear robotic systems are described. blue Insights for the extension of the introduced output-feedback adaptive neural control design approach for other architecture of nonlinear robotic systems are depicted.
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Bakhtiari, Abdolbaghi, Shahram Ehtemadi Haghighi et Adel Maghsoudpour. « Modeling and control of a flapping wing robot ». Proceedings of the Institution of Mechanical Engineers, Part K : Journal of Multi-body Dynamics 233, no 1 (24 septembre 2018) : 174–81. http://dx.doi.org/10.1177/1464419318793503.
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The dynamics and control of a flapping wing robot are studied in this paper which helps to develop a complete dynamic model for the robot consisting of tail effects and also enhance the path tracking control of the robot. In the first part of the paper, the aerodynamic model of the wings is presented, and an aerodynamic force model for the tail is introduced which includes the leading edge suction effects. An experiment is also carried out on a flapping wing robot in a laboratory environment to evaluate the forces on the tail and its result will be compared with the results of the model presented for the tail. In the second part, a controller is designed for the robot. This controller uses the nonlinear dynamic inversion method to solve the nonlinear equations of the control system. The experimental results of the tail forces agree well with the theoretical predictions and reveal that the tail aerodynamics are affected by leading edge suction. Also, simulation results show that the competence performance and convergence performance of the designed controller are obtained.
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Dai, Li, Yao Wu, Jian Wang, Yun Gong Li et Yu Liu. « Modeling and Control of Flexible Hydraulic Robotic Arm ». Advanced Engineering Forum 2-3 (décembre 2011) : 334–39. http://dx.doi.org/10.4028/www.scientific.net/aef.2-3.334.
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Flexible hydraulic robotic arm is a complicated system which coupled by mechanics and hydraulics. It is widely applied in all kinds of large engineering equipments, such as concrete pump truck, bridge monitor truck, arm frame of crane, etc. The arm system of the hydraulic robotic arm is a multi-body system with redundant freedom, strong nonlinear, coupled with rigid and flexible characters. So it is of great theoretic value and real engineering significance to study the arm system of the robotic arm. In this theme, the movement of flexible hydraulic robotic arm and hydraulic cylinders are seperately analyzed with flexible multi-body dynamics, and the mechanical hydraulic dynamic model of the driving system and the arm system is built with Lagrange Equation and Virtual Work Theory. And the dynamic differential equation is built with the driving force of the hydraulic cylinder as the main force. With the track programming and the optimization method, the dynamic converse problem of the arm end track is researched, so as to get the optimized rotation angle when the arm end reaches the expected point. By using the PD control theory, without decoupling and rank-decreasing, only with feed back from the hydraulic system to realize the close loop control of the arm end position, pose and movement, the relationship between the hydraulic system and the end position & pose is studied, so that the flexible distortion is reduced and the libration is restrained. What’s more, the simulation model of the mechanical arms is built by the dynamic simulation software. The simulation result prove that the movement equation built by this way can clearly describe each dynamic character of the mechanical arms.
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Zhu, W. D., et C. D. Mote. « Dynamic Modeling and Optimal Control of Rotating Euler-Bernoulli Beams ». Journal of Dynamic Systems, Measurement, and Control 119, no 4 (1 décembre 1997) : 802–8. http://dx.doi.org/10.1115/1.2802393.
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The nonlinear integro-differential equations, describing the transverse and rotational motions of a nonuniform Euler-Bernoulli beam with end mass attached to a rigid hub, are derived. The effects of both the linear and nonlinear elastic rotational couplings are investigated. The linear couplings are exactly accounted for in a decoupled Euler-Bernoulli beam model and their effects on the eigensolutions and response are significant for a small ratio of hub-to-beam inertia. The nonlinear couplings with a resultant stiffening effect are negligible for small angular velocities. A discretized model, suitable for the study of large angle, high speed rotation of a nonuniform beam, is presented. The optimal control moment for simultaneous vibration suppression of the beam at the end of a prescribed rotation is determined. Influences of the nonlinearity, nonuniformity, maneuver time, and inertia ratio on the optimal control moment and system response are discussed.
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Husaini, A. B., K. Anam, Samad Zahurin et M. R. Arshad. « Nonlinear Modeling and Identification of Underwater Thruster ». Advanced Materials Research 622-623 (décembre 2012) : 1217–20. http://dx.doi.org/10.4028/www.scientific.net/amr.622-623.1217.
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Complexity in modeling an underwater thruster analytically, leave system identification approached a good option on developing accurate dynamic model for underwater thruster. Nonlinearity of the system due to fluid solid interaction such as, hydrodynamic force hitting the propeller blade make the system identification became a trivial task. This paper presents nonlinear modeling and identification of the underwater thruster from input–output measurement. The system was fully submerged, and current was varied as the input and the output thrust was measured using load cell. Nonlinear Hammerstein method is chosen for identification of the system. The results are numerically and graphically presented. The nonlinear system identification with second order linear dynamics gave the best result, where is the model, can fit up to 82 % of the real response of the thrust. The finding of the model can be utilized in the future to improve underwater vehicle performance by developing optimum control algorithm.
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Yang, Zemin, Xiaopeng Li, Jinchi Xu, Renzhen Chen et Hexu Yang. « Study of Dynamic Performance and Control Strategy of Variable Stiffness Actuator System Based on Two-Inertial-System ». Mathematics 11, no 5 (27 février 2023) : 1166. http://dx.doi.org/10.3390/math11051166.
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The study of position control for variable stiffness actuators is important for improving their energy efficiency and robustness. In this paper, for the previously proposed nonlinear variable stiffness actuator, firstly, a dynamic model of the variable stiffness actuator system is established based on a two-inertia-system theory. Secondly, the effects of friction and gravity factors on the dynamic performance of the system are analyzed. The results of the study show that friction and gravity have obvious effects on the dynamic characteristics of the system in the constant stiffness state, and that these effects are more complex and obvious in the variable stiffness state, which proves the reasonableness and necessity of considering friction and gravity in the dynamics modeling process. Then, in order to improve the dynamic performance of the system and make its positioning performance meet the requirements, the control strategy of the variable stiffness actuator system is studied. The results show that the sliding mode control strategy based on nonlinear disturbance observer and dynamics model is a good solution to the effect of friction and gravity on the system, and can make its position-tracking performance meet the requirements. Finally, the correctness and effectiveness of the control strategy are verified experimentally.
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Vinay, Thurai, Bradley Postma et Theo Kangsanant. « Dynamic Modeling and Control of Dual Wheeled Mobile Robots Compliantly Coupled to a Common Payload ». Journal of Dynamic Systems, Measurement, and Control 121, no 3 (1 septembre 1999) : 457–61. http://dx.doi.org/10.1115/1.2802496.
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Lagrange formalism is applied to derive a dynamic model, and design a nonlinear controller for two nonholonomic, differentially steered, wheeled mobile robots compliantly linked to a common payload. The resulting multivariable system model is of a large order and can be block decoupled by selective state feedback into five independent subsystems, two of which effectively represent the deviation dynamics of the individual robots from a prescribed path; two others represent their forward motion dynamics; while the fifth describes the payload dynamics. Controllers for each of the robot subsystems, including self-tuning adaptive controllers for the nonlinear deviation dynamics subsystems, are designed by the pole-placement technique. System performance is then evaluated via simulation for the case where each robot is undergoing curvilinear motion.
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Hong, Qi, Tianyi Zhou et Junde Qi. « Adaptive Fuzzy Sliding Mode Control and Dynamic Modeling of Flap Wheel Polishing Force Control System ». Applied Sciences 14, no 5 (4 mars 2024) : 2153. http://dx.doi.org/10.3390/app14052153.
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Polishing force is one of the key process parameters in the polishing process of blisk blades, and its control accuracy will affect the surface quality and processing accuracy of the workpiece. The contact mechanism between the polishing surface and flap wheel was analyzed, and the calculation model of the polishing force and nonlinear dynamic model of the polishing force control system was established. Considering the influence of friction characteristics, parameter perturbation, and nonlinear dead zone on the control accuracy of the polishing force system, an adaptive fuzzy sliding mode controller (AFSMC) was designed. AFSMC uses a fuzzy system to adaptively approximate the nonlinear function terms in the sliding mode control law, adopts an exponential approach law in the switching control part of the sliding mode control (SMC), and designs the adaptive law for adjustable parameters in the fuzzy system based on the Lyapunov Theorem. Simulation and experimental results show that the designed AFSMC has a fast dynamic response, strong anti-interference ability, and high control accuracy, and it can reduce SMC high-frequency chatter. Polishing experiments show that compared with traditional PID, AFSMC can improve the form and position accuracy of the blade by 42% and reduce the surface roughness by 50%.
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Li, Shih-Yu, Shun-Hung Tsai, Chin-Sheng Chen et Lap-Mou Tam. « Adaptive Control of Advanced G-L Fuzzy Systems with Several Uncertain Terms in Membership-Matrices ». Processes 10, no 5 (23 mai 2022) : 1043. http://dx.doi.org/10.3390/pr10051043.
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In this paper, a set of novel adaptive control strategies based on an advanced G-L (proposed by Ge-Li-Tam, called GLT) fuzzy system is proposed. Three main design points can be summarized as follows: (1) the unknown parameters in a nonlinear dynamic system are regarded as extra nonlinear terms and are further packaged into so-called nonlinear terms groups for each equation through the modeling process, which reduces the complexity of the GLT fuzzy system; (2) the error dynamics are further rearranged into two parts, adjustable membership function and uncertain membership function, to aid the design of the controllers; (3) a set of adaptive controllers change with the estimated parameters and the update laws of parameters are provided following the current form of error dynamics. Two identical nonlinear dynamic systems based on a Quantum-CNN system (Q-CNN system) with two added terms are employed for simulations to demonstrate the feasibility as well as the effectiveness of the proposed fuzzy adaptive control scheme, where the tracking error can be eliminated efficiently.
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Lantos, Bela. « Some Applications of Soft Computing Methods in System Modeling and Control ». Journal of Advanced Computational Intelligence and Intelligent Informatics 2, no 3 (20 juin 1998) : 82–87. http://dx.doi.org/10.20965/jaciii.1998.p0082.
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The paper deals with the application of fuzzy systems, artificial neural networks (neural systems), and genetic algorithms to solve modeling and control problems in system engineering. Part 1 the paper covers the design of classical PID and fuzzy PID controllers for nonlinear systems with an (approximately) known dynamic model. Optimal controllers are designed based on genetic algorithms. Part 2 considers neural control of a SCARA robot. Part 3 deals with the fuzzy control of a special class of MIMO nonlinear systems and generalizes the method of Wang for such systems.
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Liu, Zeyu, et John Wagner. « Nonlinear Model Reduction for Dynamic and Automotive System Descriptions ». Journal of Dynamic Systems, Measurement, and Control 124, no 4 (1 décembre 2002) : 637–47. http://dx.doi.org/10.1115/1.1515327.
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The mathematical modeling of dynamic systems is an important task in the design, analysis, and implementation of advanced control systems. Although most vehicle control algorithms tend to use model-free calibration architectures, a need exists to migrate to model-based control algorithms which may offer greater operating performance. However, in many instances, the analytical descriptions are too complex for real-time powertrain and chassis model-based control algorithms. Thus, model reduction strategies may be applied to transform the original model into a simplified lower-order form while preserving the dynamic characteristics of the original high-order system. In this paper, an empirical gramian balanced nonlinear model reduction strategy is examined. The controllability gramian represents the energy needed to transport the system between states, while the observability gramian denotes the output energy transmitted. These gramians are then balanced and select system dynamics truncated. For comparison purposes, a Taylor Series linearization will also be introduced to linearize the original nonlinear system about an equilibrium operating point, and then a balanced realization linear reduction strategy applied to reduce the linearized model. To demonstrate the functionality of each model reduction strategy, a vehicle suspension system and exhaust gas recirculation valve are investigated, and respective transient performances are compared.
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Chen, Shuai, Dengqing Cao, Jin Wei, Guiqin He, Bo Fang et Youxia Li. « Investigations on Nonlinear Dynamic Modeling and Vibration Responses of T-Shaped Beam Structures ». Actuators 11, no 10 (12 octobre 2022) : 293. http://dx.doi.org/10.3390/act11100293.
Texte intégralRésumé :
A novel nonlinear dynamic modeling approach is proposed for the T-shaped beam structures widely used in the field of aerospace. All of the geometrical nonlinearities including the terms in the deformation of the beams, the terms at the connections, and the free ends of beams are considered in the dynamic modeling process. The global mode method is employed to determine the natural frequencies and global mode shapes of the linearized system. The validity and accuracy of the derived model are verified by comparing the natural frequencies obtained with those calculated from FEM. Adopting the Galerkin truncation procedure, a set of reduced-order nonlinear ODEs is obtained for the structure. A study on the variation of dynamic responses taking the different numbers of global modes into account is performed to determine the number of modes taken in nonlinear vibration analysis. A comparison between the responses of the system with linear or nonlinear matching and boundary conditions is given to evaluate the importance of neglecting and reserving the nonlinear terms in matching and boundary conditions. It is shown that ignoring the nonlinear terms in both matching and boundary conditions may significantly alter the responses while developing the discretized governing ODEs of the structure.
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Chen, Zhi Bin, Yan Ma et Bo Wen Su. « A Study on Nonlinear Decoupling Controller for UPFC ». Applied Mechanics and Materials 624 (août 2014) : 460–64. http://dx.doi.org/10.4028/www.scientific.net/amm.624.460.
Texte intégralRésumé :
In the d-q coordinate system, UPFC mathematical model reveals a nonlinear system with features of a multi-variable, strong coupling, and more interference. In view of these system characteristics, the paper presents a nonlinear overlapping decoupled strategy with better stability and dynamic performance for UPFC control. The control strategy is analyzed and tested with the MATLAB simulative experiments. Simulation results show that the proposed control strategy can quickly and accurately respond to the needs of the power system, and realize real power and reactive power decoupling control effectively. Keywords: Dynamic Modeling, Nonlinear, Decoupling Controller, UPFC, MATLAB
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Liu, Yunping, Xijie Huang, Tianmiao Wang, Yonghong Zhang et Xianying Li. « Nonlinear dynamics modeling and simulation of two-wheeled self-balancing vehicle ». International Journal of Advanced Robotic Systems 13, no 6 (16 novembre 2016) : 172988141667372. http://dx.doi.org/10.1177/1729881416673725.
Texte intégralRésumé :
Two-wheeled self-balancing vehicle system is a kind of naturally unstable underactuated system with high-rank unstable multivariable strongly coupling complicated dynamic nonlinear property. Nonlinear dynamics modeling and simulation, as a basis of two-wheeled self-balancing vehicle dynamics research, has the guiding effect for system design of the project demonstration and design phase. Dynamics model of the two-wheeled self-balancing vehicle is established by importing a TSi ProPac package to the Mathematica software (version 8.0), which analyzes the stability and calculates the Lyapunov exponents of the system. The relationship between external force and stability of the system is analyzed by the phase trajectory. Proportional–integral–derivative control is added to the system in order to improve the stability of the two-wheeled self-balancing vehicle. From the research, Lyapunov exponent can be used to research the stability of hyperchaos system. The stability of the two-wheeled self-balancing vehicle is better by inputting the proportional–integral–derivative control. The Lyapunov exponent and phase trajectory can help us analyze the stability of a system better and lay the foundation for the analysis and control of the two-wheeled self-balancing vehicle system.
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Bu, Wen-shao, Cong-lin Zu et Chun-xiao Lu. « Inverse System Analysis and Modeling of Bearingless Induction Motor and Its Combined Control Strategy ». Mathematical Problems in Engineering 2014 (2014) : 1–8. http://dx.doi.org/10.1155/2014/698171.
Texte intégralRésumé :
Bearingless induction motor is a multi-variable, nonlinear and strong coupling object, the existing inverse control method ignores the stator current dynamics of torque system. Aiming at its nonlinear and strong coupling problems, a novel combinatorial decoupling control strategy based on stator flux orientation and inverse system method is proposed. Taking the stator current dynamics of four-pole torque system into account, the reversibility and inverse system model of torque system are analyzed and established. Adopting the inverse system method, the dynamic decoupling between motor speed and stator flux-linkage is achieved; by online identification and calculation, the airgap flux-linkage of torque system is got. Based on above, feedback and compensation control of two radial displacement components of two-pole suspension system is realized. Simulation results have shown the higher decoupling control performance and stronger anti-interference ability of the decoupling control system; the proposed decoupling strategy not only owns the characteristics of be simple and convenient, but also is effective and feasible.
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Wu, Qianqian, Ning Cui, Sifang Zhao, Hongbo Zhang et Bilong Liu. « Modeling and Control of a Six Degrees of Freedom Maglev Vibration Isolation System ». Sensors 19, no 16 (19 août 2019) : 3608. http://dx.doi.org/10.3390/s19163608.
Texte intégralRésumé :
The environment in space provides favorable conditions for space missions. However, low frequency vibration poses a great challenge to high sensitivity equipment, resulting in performance degradation of sensitive systems. Due to the ever-increasing requirements to protect sensitive payloads, there is a pressing need for micro-vibration suppression. This paper deals with the modeling and control of a maglev vibration isolation system. A high-precision nonlinear dynamic model with six degrees of freedom was derived, which contains the mathematical model of Lorentz actuators and umbilical cables. Regarding the system performance, a double closed-loop control strategy was proposed, and a sliding mode control algorithm was adopted to improve the vibration isolation performance. A simulation program of the system was developed in a MATLAB environment. A vibration isolation performance in the frequency range of 0.01–100 Hz and a tracking performance below 0.01 Hz were obtained. In order to verify the nonlinear dynamic model and the isolation performance, a principle prototype of the maglev isolation system equipped with accelerometers and position sensors was developed for the experiments. By comparing the simulation results and the experiment results, the nonlinear dynamic model of the maglev vibration isolation system was verified and the control strategy of the system was proved to be highly effective.
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TAHAMI, FARZAD, et BEHROOZ MOLAEI. « PIECEWISE AFFINE SYSTEM MODELING AND CONTROL OF PWM CONVERTERS ». Journal of Circuits, Systems and Computers 16, no 01 (février 2007) : 113–28. http://dx.doi.org/10.1142/s0218126607003526.
Texte intégralRésumé :
The averaged switch modeling approach is a powerful method for representing the behavior of a wide variety of converters through equivalent circuits. The model is not linear and it is common to perform a small signal linearization about an operating point and design a linear controller. Models obtained with such method involve considerable approximation and produce results that are limited for high performance controller designs. In this paper a piecewise affine approximation technique is introduced for modeling PWM converters. This model is much more precise in predicting the dynamic response of averaged nonlinear model comparing the linear model. This paper also presents a piecewise linear controller synthesis method for PWM converters described by the proposed PWA model. The proposed controller is very efficient and effective. The design method is well suited for converters having a wide range of variation about their operating point. A simulation example on buck-boost converter is presented to demonstrate the performance of the proposed method for modeling the dynamics of the converter and designing the appropriate controller.
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Fei, Jun Tao, et Jing Xu. « Dynamical Modeling and Neural Network Adaptive Control of Vehicle Suspension ». Applied Mechanics and Materials 148-149 (décembre 2011) : 516–19. http://dx.doi.org/10.4028/www.scientific.net/amm.148-149.516.
Texte intégralRésumé :
This paper attempts to establish the vibration control technology based on neural network control. First, the dynamic model of vehicle suspension system is discussed, and the linear passive suspension model and nonlinear spring suspension model of the vertical acceleration are compared. It is shown that the performance of nonlinear spring suspension is better than that of the linear passive suspension model. Because of the great advantages of the neural network in dealing with the nonlinear property, secondly, model reference neural control module is introduced in the suspension system to realize the optimization of the body vertical acceleration. Simulation results demonstrate the effectiveness of the neural network adaptive controller with application to vehicle suspension.
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Abdulkareem, Ademola, Victoria Oguntosin, Olawale M. Popoola et Ademola A. Idowu. « Modeling and Nonlinear Control of a Quadcopter for Stabilization and Trajectory Tracking ». Journal of Engineering 2022 (10 octobre 2022) : 1–19. http://dx.doi.org/10.1155/2022/2449901.
Texte intégralRésumé :
This paper presents an adequate mathematical representation of a quadcopter’s system dynamics and effective control techniques. A quadcopter is an unmanned aerial vehicle (UAV) that is able to do vertical take-off and landing. This study presents a nonlinear quadcopter system’s mathematical modeling and control for stabilization and trajectory tracking. The mathematical model of the system dynamics of the quadcopter is derived using Newton and Euler equations with proper references to the appropriate frame or coordinate system. A PD control algorithm is developed for the nonlinear system for stabilization. Another nonlinear control technique called full state feedback linearization (FBL) using nonlinear dynamic inversion (NDI) is developed and implemented on the quadcopter system. However, there is a problem with the normal approach of the complete derivation of the full state FBL system using NDI as gathered from the literature review. In such an approach, the PD controller that was used for attitude stabilization was able to stabilize the angles to zero states, but the position variables cannot be stabilized because the state variables are not observable. Thus, a new approach where the position variables are mapped to the angle variables which are controllable so as to drive all states to zero stability was proposed in this study. The aim of the study was achieved but the downside is that it takes a longer time to achieve this stability so it is not efficient and should only be considered when absolute zero stability is the aim without considering time efficiency. The study further investigates the problem of nonlinear quadcopter system’s mathematical modelling and control for stabilization and trajectory tracking using the feedback linearization (FBL) technique combined with the PD controller. The proposed control algorithms are implemented on the quadcopter model using MATLAB and analyzed in terms of system stabilization and trajectory tracking. The PD controller produces satisfactory results for system stabilization, but the FBL system combined with the PD controller performs better for trajectory tracking of the quadcopter system.
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Xie, Chao-Fan, Hong Zhang et Rey-Chue Hwang. « Discrete Dynamic System Modeling for Simulated Moving Bed Processes ». Mathematics 12, no 10 (13 mai 2024) : 1520. http://dx.doi.org/10.3390/math12101520.
Texte intégralRésumé :
Although the simulated moving bed (SMB) process boasts advantages such as high productivity and low consumption, the cost of obtaining optimized parameters through practical experiments to control the separation process can be enormous due to its complex nonlinear characteristics. Consequently, the successful transformation of the SMB separation process into a mathematical dynamic model for computer simulation would greatly reduce the research costs associated with experimental studies. In this study, the Crank–Nicolson method was employed to discretize and dynamize the SMB process, enabling the simulation of processes under both linear and Langmuir isotherms. The results of the simulation experiments demonstrated the feasibility and high efficiency of this approach, thereby establishing a solid foundation for further advancements in online control strategies.
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Baysal, Cabbar Veysel. « An Inverse Dynamics-Based Control Approach for Compliant Control of Pneumatic Artificial Muscles ». Actuators 11, no 4 (16 avril 2022) : 111. http://dx.doi.org/10.3390/act11040111.
Texte intégralRésumé :
Rehabilitation is an area of robotics in which human–robot collaboration occurs, requiring adaptation and compliance. Pneumatic artificial muscles (PAM) are soft actuators that have built-in compliance making them usable for rehabilitation robots. Conversely, compliance arises from nonlinear characteristics and generates obstructions in modeling and controlling actions. It is a critical issue limiting the use of PAM. In this work, multi-input single-output (MISO) inverse modeling and inverse dynamics model learning approaches are combined to obtain a novel nonlinear adaptive control scheme for single PAM-actuated 1-DoF rehabilitation devices, for instance, continuous passive motion (CPM) devices. The objective of the proposed system is to bring an alternative solution to the compliant operation of PAM while performing exercise trajectories, to satisfy requirements such as larger range of motion (ROM) and adaptability to external load impedance variations. The control system combines the operation of a nonlinear autoregressive network with exogenous inputs (NARX)-based inverse dynamics estimator used as a global range controller and cascade PIDs for local position and pressure loops. Implementation results demonstrated the efficacy of the introduced method in terms of compliant operation for dynamic external load variations as well as a stable operation in case of impulsive disturbances. To summarize, a simple but efficient method is illustrated to facilitate the common use of PAM.
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Zhang, Tingting, et Jianying Yang. « Nonlinear dynamics and robust control of sloshing in a tank ». Journal of Vibration and Control 25, no 1 (24 avril 2018) : 132–40. http://dx.doi.org/10.1177/1077546318772256.
Texte intégralRésumé :
Sloshing is a complex nonlinear dynamic phenomenon which has a significant influence on the stability of structure–fluid systems. In this study, the dynamic equation of sloshing based on Hamilton principle is established and linearized into a state space equation. Considering the uncertainty of the system, a robust H infinite guaranteed cost control method is proposed to mitigate the response of fluid wave height to horizontal acceleration of the tank body. Simulation results are given to demonstrate the closed-loop performance of the nonlinear dynamic modeling and linear optimal control method.
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Zhao, Jie, Li Wang, Dichen Liu, Jun Wang, Yu Zhao, Tian Liu et Haoyu Wang. « Dynamic Model of Kaplan Turbine Regulating System Suitable for Power System Analysis ». Mathematical Problems in Engineering 2015 (2015) : 1–12. http://dx.doi.org/10.1155/2015/294523.
Texte intégralRésumé :
Accurate modeling of Kaplan turbine regulating system is of great significance for grid security and stability analysis. In this paper, Kaplan turbine regulating system model is divided into the governor system model, the blade control system model, and the turbine and water diversion system model. The Kaplan turbine has its particularity, and the on-cam relationship between the wicket gate opening and the runner blade angle under a certain water head on the whole range was obtained by high-order curve fitting method. Progressively the linearized Kaplan turbine model, improved ideal Kaplan turbine model, and nonlinear Kaplan turbine model were developed. The nonlinear Kaplan turbine model considered the correction function of the blade angle on the turbine power, thereby improving the model simulation accuracy. The model parameters were calculated or obtained by the improved particle swarm optimization (IPSO) algorithm. For the blade control system model, the default blade servomotor time constant given by value of one simplified the modeling and experimental work. Further studies combined with measured test data verified the established model accuracy and laid a foundation for further research into the influence of Kaplan turbine connecting to the grid.
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Kakizaki, T., J. F. Deck et S. Dubowsky. « Modeling the Spatial Dynamics of Robotic Manipulators with Flexible Links and Joint Clearances ». Journal of Mechanical Design 115, no 4 (1 décembre 1993) : 839–47. http://dx.doi.org/10.1115/1.2919277.
Texte intégralRésumé :
A dynamic modeling method is presented for spatial elastic manipulators that can account for a number of their realistic properties, including bearing clearances, actuator dynamics, and control system characteristics. Forces in the bearing clearances are modeled by nonlinear functions of the links’ relative motions and the internal geometry of the connection, or by experimentally measured properties. A detailed model is given for a revolute connection with radial and axial clearances. Results obtained for a SCARA manipulator show that the combined dynamic effects of bearing clearances, link elasticity, and control system characteristics can significantly degrade the system’s performance.
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Ingrosso, Roberta, Daniela De Palma, Giulio Avanzini et Giovanni Indiveri. « Dynamic Modeling of Underwater Multi-Hull Vehicles ». Robotica 38, no 9 (25 novembre 2019) : 1682–702. http://dx.doi.org/10.1017/s0263574719001693.
Texte intégralRésumé :
SUMMARYThis paper describes a modeling approach to compute the lumped parameter hydrodynamic derivative matrices of an underwater multi-hull vehicle. The vehicle, modeled as a multi-body underwater system and denoted as cluster, can be composed by heterogeneous bodies with known dynamic parameters, rigidly connected. The nonlinear dynamic equations of the cluster and its parameters are derived by means of a modular approach, based on the composition of single basic elements. The ultimate objective is to derive a mathematical description of the multi-hull system that captures its most significant dynamics allowing to design model-based motion controllers and navigation filters. The modular nature of the resulting model can be exploited, by example, when control reconfiguration is to be dealt with in the presence of (possibly multiple) failures. The numerical simulation of a hypothetical cluster is presented and discussed.
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Moskwa, J. J., et J. K. Hedrick. « Modeling and Validation of Automotive Engines for Control Algorithm Development ». Journal of Dynamic Systems, Measurement, and Control 114, no 2 (1 juin 1992) : 278–85. http://dx.doi.org/10.1115/1.2896525.
Texte intégralRésumé :
There is considerable interest in coordinated automotive engine/transmission control to smooth shifts, and for traction control of front wheel vehicles. This paper outlines a nonlinear dynamic engine model of a port fuel-injected engine, which can be used for control algorithm development. This engine model predicts the mean engine brake torque as a function of the engine controls (i.e., throttle angle, spark advance, fuel flow rate, and exhaust gas recirculation (E. G. R.) flow rate). The model has been experimentally validated for a specific engine, and includes: • intake manifold dynamics, • fuel delivery dynamics, and • process delays inherent in the four-stroke engine. This model is used in real time within a control algorithm, and for system simulation. Also, it is flexible enough to represent a family of spark ignition automotive engines, given some test and/or simulation data for setting parameters.
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Yang, Du Wei, Jian Zhong Zhou et Jun Chao Dong. « Modeling Study of Aircraft Based on Small Perturbation Equation ». Advanced Materials Research 466-467 (février 2012) : 1407–12. http://dx.doi.org/10.4028/www.scientific.net/amr.466-467.1407.
Texte intégralRésumé :
In aircraft flight control law design, the first key is to establish actual aircraft mathematical model, then according to the model of dynamic output information, analysis control law design is appropriate. But in the movement the aircraft is a complex dynamics system, modeling is very complex. This paper firstly carry out comprehensive feasibility analysis, on a plane modeling consideration simplified, secondly, in actual applications verified using the perturbation method of nonlinear equation linearization, establish the plane mathematics model.
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Li, Xiao-Huan, Fang Liu, Jia Xu et Zhi-Wen Zhu. « Nonlinear dynamic characteristics and control of Galfenol-Shape Memory Alloy composite plate subjected to stochastic excitation ». International Journal of Applied Electromagnetics and Mechanics 64, no 1-4 (10 décembre 2020) : 1547–54. http://dx.doi.org/10.3233/jae-209476.
Texte intégralRésumé :
In this paper, the nonlinear dynamic characteristics and control of a Galfenol-shape memory alloy (SMA) composite plate under stochastic excitation are studied. New nonlinear differential terms are applied in the constitutive modeling of Galfenol alloy and SMA, and the nonlinear dynamic model of the composite system is developed. The drift coefficient and the diffusion coefficient are calculated to obtain the steady-state probability density function of the system, and finally the optimal control strategy is proposed to improve the effects of vibration reduction. Numerical simulation and experiments results show that the system has abundant nonlinear dynamic characteristics, including stochastic Hopf bifurcation and limit cycle bifurcation. The stochastic optimal control strategy can improve the effects of vibration reduction efficiently. These results are helpful for the application of Galfenol-SMA composite structures.
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Pramod, B. R., et S. C. Bose. « System Identification Using ARMA Modeling and Neural Networks ». Journal of Engineering for Industry 115, no 4 (1 novembre 1993) : 487–91. http://dx.doi.org/10.1115/1.2901794.
Texte intégralRésumé :
Stochastic system identification is an important tool for control of discrete dynamic systems. Among the modeling strategies developed for this purpose, Auto Regressive Moving Average (ARMA for discrete systems) models offer an accurate identification technique. The disadvantage with these models are that they are extremely complicated to implement on-line, especially for nonlinear time-variant systems. This paper utilizes a Neural Network structure for identification of stochastic processes and tracks system dynamics by on-line adjustments of network parameters. Neural dynamics is based on impulse responses and an iterative learning algorithm is derived using conventional principles of gradient descent and backpropagation. The learning algorithm is analyzed and shown to be fast and accurate in the identification of parameters for stochastic processes in both time-invariant and time-variant cases.
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CHEN, GUANRONG, et XIAONING DONG. « ON FEEDBACK CONTROL OF CHAOTIC NONLINEAR DYNAMIC SYSTEMS ». International Journal of Bifurcation and Chaos 02, no 02 (juin 1992) : 407–11. http://dx.doi.org/10.1142/s0218127492000392.
Texte intégralRésumé :
In this paper, some interesting analysis and simulations on the control of chaotic dynamic systems using conventional feedback control strategies are presented. The typical discrete-time chaotic Lozi system is investigated in some detail. The trajectories of the chaotic Lozi system are controlled to its equilibrium points using conventional feedback controls. Analysis on the design of the feedback controllers and its computer simulations are included.
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Pourboghrat, Farzad, Harin Pongpairoj, Ziqian Liu, Farshad Farid, Farhang Pourboghrat et Behnaam Aazhang. « Dynamic Neural Networks for Modeling and Control of Nonlinear Systems ». Intelligent Automation & ; Soft Computing 9, no 2 (janvier 2003) : 61–70. http://dx.doi.org/10.1080/10798587.2000.10642843.
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Li, Shih-Yu, Chin-Sheng Chen, Lap-Mou Tam et Shun-Hung Tsai. « Novel Fuzzy-Modeling-Based Adaptive Synchronization of Nonlinear Dynamic Systems ». Complexity 2017 (2017) : 1–8. http://dx.doi.org/10.1155/2017/5017127.
Texte intégralRésumé :
In this paper, a novel fuzzy-model-based adaptive synchronization scheme and its fuzzy update laws of parameters are proposed to address the adaptive synchronization problem. The proposed fuzzy controller does not share the same premise of fuzzy system, and the numbers of fuzzy controllers is reduced effectively through the novel modeling strategy. In addition, based on the adaptive synchronization scheme, the error dynamic system can be guaranteed to be asymptotically stable and the true values of unknown parameters can be obtained. Two identical complicated dynamic systems, Mathieu-Van der pol system (M-V system) with uncertainties, are illustrated for numerical simulation example to show the effectiveness and feasibility of the proposed novel adaptive control strategy.