A space robot inevitably impacts a satellite in a capture operation. If its fragile joints are not protected, they may be damaged, resulting in failure of the capture operation. Thus, a spring damper buffer device (SDBD) is added between the joint motors and manipulators to absorb the impact energy, and provide a compliance strategy matched with the SDBD for stable control of the hybrid system. The dynamic modes of the dual-arm space robot open-loop system and target satellite system are established by the Lagrange function before capture. From the momentum theorem, velocity constraints, closed-chain geometric constraints, and Newton?s third law, the closedchain dynamic model of the hybrid system after capture is obtained, and the impact effect and impact force are calculated. For stable control of the hybrid system while limiting joint? impact torque within the safe range, an adaptive fractional-order super-twisting sliding mode compliance control strategy matching the SDBD is proposed. It can effectively improve the fast convergence and trajectory tracking performance of the system whose velocity and acceleration cannot be measured. The stability of the hybrid system is demonstrated by the Lyapunov theorem, and the anti-impact performance of the SDBD and the effectiveness of the compliance strategy are demonstrated through numerical simulation.
{"title":"FSTSMC Compliance Control for Dual-Arm Space Robot with SDBD Capture Satellite Operation","authors":"Zhu An, Haiping Ai, Chen Li","doi":"10.1115/1.4062268","DOIUrl":"https://doi.org/10.1115/1.4062268","url":null,"abstract":"\u0000 A space robot inevitably impacts a satellite in a capture operation. If its fragile joints are not protected, they may be damaged, resulting in failure of the capture operation. Thus, a spring damper buffer device (SDBD) is added between the joint motors and manipulators to absorb the impact energy, and provide a compliance strategy matched with the SDBD for stable control of the hybrid system. The dynamic modes of the dual-arm space robot open-loop system and target satellite system are established by the Lagrange function before capture. From the momentum theorem, velocity constraints, closed-chain geometric constraints, and Newton?s third law, the closedchain dynamic model of the hybrid system after capture is obtained, and the impact effect and impact force are calculated. For stable control of the hybrid system while limiting joint? impact torque within the safe range, an adaptive fractional-order super-twisting sliding mode compliance control strategy matching the SDBD is proposed. It can effectively improve the fast convergence and trajectory tracking performance of the system whose velocity and acceleration cannot be measured. The stability of the hybrid system is demonstrated by the Lyapunov theorem, and the anti-impact performance of the SDBD and the effectiveness of the compliance strategy are demonstrated through numerical simulation.","PeriodicalId":54858,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":"1 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90672967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nonlinear analysis of complex traffic flow systems can provide a deep understanding of the causes of various traffic phenomena and reduce traffic congestion, and bifurcation analysis is a powerful method for it. In this paper, based on the improved Aw-Rascle model, a new macroscopic traffic flow model is proposed, which takes into account the road factors and driver psychological factor in the curve environment which can effectively simulate many realistic traffic phenomena on curves. The macroscopic traffic flow model on curved road is analyzed by bifurcation, firstly, it is transformed into a nonlinear dynamical system, then its stability conditions and the existence conditions of bifurcations are derived, and the changes of trajectories near the equilibrium points are described by phase plane. From an equilibrium point, various bifurcation structures describing the nonlinear traffic flow are obtained. In this paper, the influence of different bifurcations on traffic flow is analyzed, and the causes of special traffic phenomena such as stop-and-go and traffic clustering are described using Hopf bifurcation as the starting point of density temporal evolution. The derivation and simulation show that both road factors and driver psychological factor affect the stability of traffic flow on curves, and the study of bifurcation in the curved traffic flow model provides decision support for traffic management.
{"title":"Bifurcation Analysis of Improved Traffic Flow Model On Curved Road","authors":"","doi":"10.1115/1.4062267","DOIUrl":"https://doi.org/10.1115/1.4062267","url":null,"abstract":"\u0000 Nonlinear analysis of complex traffic flow systems can provide a deep understanding of the causes of various traffic phenomena and reduce traffic congestion, and bifurcation analysis is a powerful method for it. In this paper, based on the improved Aw-Rascle model, a new macroscopic traffic flow model is proposed, which takes into account the road factors and driver psychological factor in the curve environment which can effectively simulate many realistic traffic phenomena on curves. The macroscopic traffic flow model on curved road is analyzed by bifurcation, firstly, it is transformed into a nonlinear dynamical system, then its stability conditions and the existence conditions of bifurcations are derived, and the changes of trajectories near the equilibrium points are described by phase plane. From an equilibrium point, various bifurcation structures describing the nonlinear traffic flow are obtained. In this paper, the influence of different bifurcations on traffic flow is analyzed, and the causes of special traffic phenomena such as stop-and-go and traffic clustering are described using Hopf bifurcation as the starting point of density temporal evolution. The derivation and simulation show that both road factors and driver psychological factor affect the stability of traffic flow on curves, and the study of bifurcation in the curved traffic flow model provides decision support for traffic management.","PeriodicalId":54858,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":"14 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78633839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Highly deformable Modular Soft Robots (MSoRos) have the unique ability to assemble into different topologies, e.g., planar and spherical, which display widely different locomotion modes (e.g., crawling or rolling). This research presents topology design and optimization methodology of MSoRos based on Archimedean solids capable of both heterogeneous and homogeneous spherical and planar reconfiguration. The sequential approach comprises of forward and inverse design processes. The forward design process, based on a selected polyhedron (either Archemedian or Platonic solid), models the robot topology in spherical configuration and generates the planar topology. The inverse design creates the spherical topology given using the planar topology. Reconfiguration alignment is ensured using the discussed polyhedron vertex alignment principle, and the planar and spherical distortion metrics are defined to characterize distortions due to reconfiguration. Optimal topology is obtained by minimizing a cost function that is a weighted sum of the two distortion metrics. As the design processes involve nonlinear projections, the starting base polyhedron for forward design is critical (Archemedian for heterogeneous and Platonic for homogeneous). The optimal trajectory is explored for both the scenarios and with varying weights in the cost function. The result is an MSoRo capable of distinct 1-D and 2-D planar configurations (both heterogeneous and homogeneous) and multiple 3-D spherical configurations of varying radii (both heterogeneous and homogeneous). The methodology is tested on an MSoRo system based on a cuboctahedron (Archimedean solid) and a cube and an octahedron (Platonic solids).
{"title":"Topology Design and Optimization of Modular Soft Robots (msoros) Capable of Homogenous and Heterogenous Reconfiguration","authors":"","doi":"10.1115/1.4062265","DOIUrl":"https://doi.org/10.1115/1.4062265","url":null,"abstract":"\u0000 Highly deformable Modular Soft Robots (MSoRos) have the unique ability to assemble into different topologies, e.g., planar and spherical, which display widely different locomotion modes (e.g., crawling or rolling). This research presents topology design and optimization methodology of MSoRos based on Archimedean solids capable of both heterogeneous and homogeneous spherical and planar reconfiguration. The sequential approach comprises of forward and inverse design processes. The forward design process, based on a selected polyhedron (either Archemedian or Platonic solid), models the robot topology in spherical configuration and generates the planar topology. The inverse design creates the spherical topology given using the planar topology. Reconfiguration alignment is ensured using the discussed polyhedron vertex alignment principle, and the planar and spherical distortion metrics are defined to characterize distortions due to reconfiguration. Optimal topology is obtained by minimizing a cost function that is a weighted sum of the two distortion metrics. As the design processes involve nonlinear projections, the starting base polyhedron for forward design is critical (Archemedian for heterogeneous and Platonic for homogeneous). The optimal trajectory is explored for both the scenarios and with varying weights in the cost function. The result is an MSoRo capable of distinct 1-D and 2-D planar configurations (both heterogeneous and homogeneous) and multiple 3-D spherical configurations of varying radii (both heterogeneous and homogeneous). The methodology is tested on an MSoRo system based on a cuboctahedron (Archimedean solid) and a cube and an octahedron (Platonic solids).","PeriodicalId":54858,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":"2 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80598522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The application of servo-controlled mechanical-bearing-based precision motion stages (MBMS) is well-established in advanced manufacturing, semiconductor industries, and metrological applications. Nevertheless, the performance of the motion stage is plagued by self-excited friction-induced vibrations. Recently, a passive mechanical friction isolator (FI) has been introduced to reduce the adverse impact of friction in MBMS, and accordingly, the dynamics of MBMS with FI were analyzed in the previous works. However, in the previous works, the nonlinear dynamics components of FI were not considered for the dynamical analysis of MBMS. This work presents a comprehensive, thorough analysis of an MBMS with a nonlinear FI. A servo-controlled MBMS with a nonlinear FI is modeled as a two DOF spring-mass-damper lumped parameter system. The linear stability analysis in the parametric space of reference velocity signal and differential gain reveals that including nonlinearity in FI significantly increases local stability of the system's steady-states. This further allows the implementation of larger differential gains in the servo-controlled motion stage. Furthermore, we perform a nonlinear analysis of the system and observe the existence of sub and supercritical Hopf bifurcation with or without any nonlinearity in the friction isolator. However, the region of Sub and Supercritical Hopf bifurcation on stability curves depends on the nonlinearity in FI. These observations are further verified by a detailed numerical bifurcation which reveals the existence of nonlinear attractors in the system.
{"title":"Stability and Bifurcation Analysis of Precision Motion Stage with Nonlinear Friction Isolator","authors":"S. K. Gupta, Ehab E. Basta, O. Barry","doi":"10.1115/1.4062266","DOIUrl":"https://doi.org/10.1115/1.4062266","url":null,"abstract":"\u0000 The application of servo-controlled mechanical-bearing-based precision motion stages (MBMS) is well-established in advanced manufacturing, semiconductor industries, and metrological applications. Nevertheless, the performance of the motion stage is plagued by self-excited friction-induced vibrations. Recently, a passive mechanical friction isolator (FI) has been introduced to reduce the adverse impact of friction in MBMS, and accordingly, the dynamics of MBMS with FI were analyzed in the previous works. However, in the previous works, the nonlinear dynamics components of FI were not considered for the dynamical analysis of MBMS. This work presents a comprehensive, thorough analysis of an MBMS with a nonlinear FI. A servo-controlled MBMS with a nonlinear FI is modeled as a two DOF spring-mass-damper lumped parameter system. The linear stability analysis in the parametric space of reference velocity signal and differential gain reveals that including nonlinearity in FI significantly increases local stability of the system's steady-states. This further allows the implementation of larger differential gains in the servo-controlled motion stage. Furthermore, we perform a nonlinear analysis of the system and observe the existence of sub and supercritical Hopf bifurcation with or without any nonlinearity in the friction isolator. However, the region of Sub and Supercritical Hopf bifurcation on stability curves depends on the nonlinearity in FI. These observations are further verified by a detailed numerical bifurcation which reveals the existence of nonlinear attractors in the system.","PeriodicalId":54858,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":"44 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90419278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Predictive simulations of human motion are a precious resource for a deeper understanding of the motor control policies encoded by the central nervous system. They also have profound implications for the design and control of assistive and rehabilitation devices, for ergonomics, as well as for surgical planning. However, the potential of state-of-the-art predictive approaches is not fully realized yet, making it difficult to draw convincing conclusions about the actual optimality principles underlying human walking. In the present study, we propose a novel formulation of a bilevel, inverse optimal control strategy based on a full-body three-dimensional neuromusculoskeletal model. In the lower level, prediction of walking is formulated as a principled multi-objective optimal control problem based on a weighted Chebyshev metric, whereas the contributions of candidate control objectives are systematically and efficiently identified in the upper level. Our framework has proved to be effective in determining the contributions of the selected objectives and in reproducing salient features of human locomotion. Nonetheless, some deviations from the experimental kinematic and kinetic trajectories have emerged, suggesting directions for future research. The proposed framework can serve as an inverse optimal control platform for testing multiple optimality criteria, with the ultimate goal of learning the control objectives that best explain observed human motion.2
{"title":"Identification of Motor Control Objectives in Human Locomotion via Multi-Objective Inverse Optimal Control","authors":"Matilde Tomasi, Alessio Artoni","doi":"10.1115/1.4056588","DOIUrl":"https://doi.org/10.1115/1.4056588","url":null,"abstract":"Abstract Predictive simulations of human motion are a precious resource for a deeper understanding of the motor control policies encoded by the central nervous system. They also have profound implications for the design and control of assistive and rehabilitation devices, for ergonomics, as well as for surgical planning. However, the potential of state-of-the-art predictive approaches is not fully realized yet, making it difficult to draw convincing conclusions about the actual optimality principles underlying human walking. In the present study, we propose a novel formulation of a bilevel, inverse optimal control strategy based on a full-body three-dimensional neuromusculoskeletal model. In the lower level, prediction of walking is formulated as a principled multi-objective optimal control problem based on a weighted Chebyshev metric, whereas the contributions of candidate control objectives are systematically and efficiently identified in the upper level. Our framework has proved to be effective in determining the contributions of the selected objectives and in reproducing salient features of human locomotion. Nonetheless, some deviations from the experimental kinematic and kinetic trajectories have emerged, suggesting directions for future research. The proposed framework can serve as an inverse optimal control platform for testing multiple optimality criteria, with the ultimate goal of learning the control objectives that best explain observed human motion.2","PeriodicalId":54858,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136329110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to reveal the mechanism of curve passing for medium-low speed maglev, this paper firstly studies the necessary conditions for the conventional wheelset curve passing based on the mechanism of curve passing for the conventional wheelset. Secondly, on the basis of comparing the structure and motion relationship of the conventional wheelset, the theoretical derivation of the magnetic wheelset curve passing conditions are carried out. Finally, the conditions of curve passing for the magnetic wheelset are verified by dynamic simulation. Through the research, it can be found that: 1) The mechanism of curve passing for the magnetic wheelset is different from that of wheelset and independent wheelset. The speed variance and regulating torque are the composite functions of speed, curve radius, track gauge, superelevation, guiding stiffness and yaw angle of the magnetic wheelset. 2) When the magnetic wheelset passes through the curve, its motion posture switches between "?" and "?" ;, while the unilateral magnetic wheel shows a motion which is similar to "hunting". 3) Ignoring the factors such as structure and irregularity, it can conduct that the curve capacity of the magnetic wheelset could be improved by increasing the curve radius, reducing the speed, curve superelevation and gauge to a certain extent. This study theoretically reveals the mechanism of curve passing for the medium-low speed maglev, which provides a certain reference for the subsequent design of the medium-low speed maglev and the improvement of the medium-low speed maglev curve capacity.
{"title":"Research on the Mechanism of Curve Passing for Bogie on a Medium-Low speed Maglev with Mid-Set Air Spring","authors":"Bo Wang, S. Luo, Jing Liu, Weihua Ma, Jie Xu","doi":"10.1115/1.4062226","DOIUrl":"https://doi.org/10.1115/1.4062226","url":null,"abstract":"\u0000 In order to reveal the mechanism of curve passing for medium-low speed maglev, this paper firstly studies the necessary conditions for the conventional wheelset curve passing based on the mechanism of curve passing for the conventional wheelset. Secondly, on the basis of comparing the structure and motion relationship of the conventional wheelset, the theoretical derivation of the magnetic wheelset curve passing conditions are carried out. Finally, the conditions of curve passing for the magnetic wheelset are verified by dynamic simulation. Through the research, it can be found that: 1) The mechanism of curve passing for the magnetic wheelset is different from that of wheelset and independent wheelset. The speed variance and regulating torque are the composite functions of speed, curve radius, track gauge, superelevation, guiding stiffness and yaw angle of the magnetic wheelset. 2) When the magnetic wheelset passes through the curve, its motion posture switches between \"?\" and \"?\" ;, while the unilateral magnetic wheel shows a motion which is similar to \"hunting\". 3) Ignoring the factors such as structure and irregularity, it can conduct that the curve capacity of the magnetic wheelset could be improved by increasing the curve radius, reducing the speed, curve superelevation and gauge to a certain extent. This study theoretically reveals the mechanism of curve passing for the medium-low speed maglev, which provides a certain reference for the subsequent design of the medium-low speed maglev and the improvement of the medium-low speed maglev curve capacity.","PeriodicalId":54858,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":"6 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82525842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nguyen Anh Tuan, V. T. Nguyen, D. Baleanu, Van Thin Nguyen
In this paper, we investigate the well-posedness of mild solutions of the time-fractional diffusion equation with an exponential source function and the Caputo-Fabrizio derivative of a fractional order alpha in (0; 1). Some linear estimates of the solution kernels on Hilbert scale spaces are constructed using a spectrum of the Dirichlet Laplacian. Based on the Banach xed point theorem, the global existence and uniqueness of the small-data mild solution are approved. This work is considered the first study on the time-fractional diffusion equation with a nonlinear function for all common dimensions of 1, 2 and 3.
{"title":"On the Fractional Diffusion Equation Associated with Exponential Source and Operator with Exponential Kernel","authors":"Nguyen Anh Tuan, V. T. Nguyen, D. Baleanu, Van Thin Nguyen","doi":"10.1115/1.4062198","DOIUrl":"https://doi.org/10.1115/1.4062198","url":null,"abstract":"\u0000 In this paper, we investigate the well-posedness of mild solutions of the time-fractional diffusion equation with an exponential source function and the Caputo-Fabrizio derivative of a fractional order alpha in (0; 1). Some linear estimates of the solution kernels on Hilbert scale spaces are constructed using a spectrum of the Dirichlet Laplacian. Based on the Banach xed point theorem, the global existence and uniqueness of the small-data mild solution are approved. This work is considered the first study on the time-fractional diffusion equation with a nonlinear function for all common dimensions of 1, 2 and 3.","PeriodicalId":54858,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":"31 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80634937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, period-1 motions to twin spiral homoclinic orbits in the Rossler system are presented. The period-1 motions varying with a systems parameter are predicted semi-analytically through an implicit mapping method, and the corresponding stability and bifurcations of the period-1 motions are determined through eigenvalue analysis. The approximate homoclinic orbits are obtained, which can be detected through the periodic motions with the positive and negative infinite large eigenvalues. The two limit ends of the bifurcation diagram of the period-1 motion are at twin spiral homoclinic orbits. For comparison, numerical and analytical results of stable period-1 motion are presented. The approximate spiral homoclinic orbits are demonstrated for a better understanding of complex dynamics of homoclinic orbits. Herein, only initial results on periodic motions to homoclinic orbits are presented for the Rossler system. In fact, the Rossler system has rich complex dynamics existing in other high-dimensional nonlinear systems. Thus, the further studies of bifurcation trees of periodic motions to infinite homoclinic orbits will be completed in sequel.
{"title":"Period-1 Motions to Twin Spiral Homoclinic Orbits in the Rössler System","authors":"","doi":"10.1115/1.4062201","DOIUrl":"https://doi.org/10.1115/1.4062201","url":null,"abstract":"\u0000 In this paper, period-1 motions to twin spiral homoclinic orbits in the Rossler system are presented. The period-1 motions varying with a systems parameter are predicted semi-analytically through an implicit mapping method, and the corresponding stability and bifurcations of the period-1 motions are determined through eigenvalue analysis. The approximate homoclinic orbits are obtained, which can be detected through the periodic motions with the positive and negative infinite large eigenvalues. The two limit ends of the bifurcation diagram of the period-1 motion are at twin spiral homoclinic orbits. For comparison, numerical and analytical results of stable period-1 motion are presented. The approximate spiral homoclinic orbits are demonstrated for a better understanding of complex dynamics of homoclinic orbits. Herein, only initial results on periodic motions to homoclinic orbits are presented for the Rossler system. In fact, the Rossler system has rich complex dynamics existing in other high-dimensional nonlinear systems. Thus, the further studies of bifurcation trees of periodic motions to infinite homoclinic orbits will be completed in sequel.","PeriodicalId":54858,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":"2 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88834173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Luo Runzi, Zijun Song, Shuai Liu, Jiaojiao Fu, Fang Zhang
Fixed-time synchronization of fractional-order multilayer complex networks is studied in this paper. At first, a novel fixed-time stability theorem for the fractional-order nonlinear system is presented. The stability theorem is a generalization of the integer order stability theorem and plays an important role on the synchronization schemes. Based on the proposed stability theorem, the fixed-time synchronization of fractional-order multilayer complex networks is investigated and a fixed-time synchronization criterion is presented. Simulation results are given to demonstrate the effectiveness of our results.
{"title":"Fixed-Time Synchronization of Fractional-Order Multilayer Complex Networks via a New Fixed-Time Stability Theorem","authors":"Luo Runzi, Zijun Song, Shuai Liu, Jiaojiao Fu, Fang Zhang","doi":"10.1115/1.4062200","DOIUrl":"https://doi.org/10.1115/1.4062200","url":null,"abstract":"\u0000 Fixed-time synchronization of fractional-order multilayer complex networks is studied in this paper. At first, a novel fixed-time stability theorem for the fractional-order nonlinear system is presented. The stability theorem is a generalization of the integer order stability theorem and plays an important role on the synchronization schemes. Based on the proposed stability theorem, the fixed-time synchronization of fractional-order multilayer complex networks is investigated and a fixed-time synchronization criterion is presented. Simulation results are given to demonstrate the effectiveness of our results.","PeriodicalId":54858,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":"4034 2 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86725303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Guanchu Chen, Hiroki Yamashita, Y. Ruan, P. Jayakumar, D. Gorsich, J. Knap, K. Leiter, Xiaobo Yang, H. Sugiyama
A new hierarchical multiscale terrain model is developed using the material point method (MPM) to enable effective modeling of large terrain deformation for high-fidelity off-road mobility simulations. Unlike the Lagrangian finite-element model, MPM allows for modeling large deformation of a continuum without mesh distortion using material points as moving quadrature points for the background grid. This unique feature is extended to account for complex granular soil material behavior with the hierarchical multiscale modeling approach in the context of off-road mobility simulations. The grain-scale discrete-element (DE) representative volume element (RVE) and its neural network surrogate model (ANN) are developed and introduced to the upper-scale MPM model through the scale-bridging algorithm. The DE RVE is used to generate training data for the ANN RVE, allowing for predicting the history-dependent grain-scale soil material behavior efficiently at every material point that moves through the upper-scale MPM background grid. A numerical procedure for modeling the interaction of the nonlinear FE tire model with the MPM-ANN multiscale terrain model is developed considering moving soil patches generalized for the upper-scale MPM terrain model. It is fully integrated into the general off-road mobility simulation framework by leveraging scalable high-performance computing techniques. The predictive ability of the proposed MPM-ANN multiscale off-road mobility model is examined and validated against the full-scale vehicle test data, involving large deformation of soft terrain. The computational benefit from the neural network surrogate model is also demonstrated.
{"title":"Hierarchical MPM-ANN Multiscale Terrain Model for High-Fidelity Off-Road Mobility Simulations: A Coupled MBD-FE-MPM-ANN Approach","authors":"Guanchu Chen, Hiroki Yamashita, Y. Ruan, P. Jayakumar, D. Gorsich, J. Knap, K. Leiter, Xiaobo Yang, H. Sugiyama","doi":"10.1115/1.4062204","DOIUrl":"https://doi.org/10.1115/1.4062204","url":null,"abstract":"\u0000 A new hierarchical multiscale terrain model is developed using the material point method (MPM) to enable effective modeling of large terrain deformation for high-fidelity off-road mobility simulations. Unlike the Lagrangian finite-element model, MPM allows for modeling large deformation of a continuum without mesh distortion using material points as moving quadrature points for the background grid. This unique feature is extended to account for complex granular soil material behavior with the hierarchical multiscale modeling approach in the context of off-road mobility simulations. The grain-scale discrete-element (DE) representative volume element (RVE) and its neural network surrogate model (ANN) are developed and introduced to the upper-scale MPM model through the scale-bridging algorithm. The DE RVE is used to generate training data for the ANN RVE, allowing for predicting the history-dependent grain-scale soil material behavior efficiently at every material point that moves through the upper-scale MPM background grid. A numerical procedure for modeling the interaction of the nonlinear FE tire model with the MPM-ANN multiscale terrain model is developed considering moving soil patches generalized for the upper-scale MPM terrain model. It is fully integrated into the general off-road mobility simulation framework by leveraging scalable high-performance computing techniques. The predictive ability of the proposed MPM-ANN multiscale off-road mobility model is examined and validated against the full-scale vehicle test data, involving large deformation of soft terrain. The computational benefit from the neural network surrogate model is also demonstrated.","PeriodicalId":54858,"journal":{"name":"Journal of Computational and Nonlinear Dynamics","volume":"23 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73107647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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