T. Wasfy, Hatem M. Wasfy, P. Jayakumar, Srinivas Sanikommu
A finite element vegetation model is presented for predicting the dynamic interaction of ground vehicles with vegetation. The purpose of the model is to predict ground vehicle mobility over vegetation covered terrains. The types of vegetation can range from small diameter highly compliant stems to large stiff trees. Those include various types of vegetation such as grass, crops, shrubs/bushes, small trees, and large trees. Mobility measures which can be predicted include maximum safe vehicle speed along a specified path, tire slip, and fuel consumption. The ground vehicles are modeled using high-fidelity multibody dynamics models. The vegetation stems are modeled using an arrangement of thin and/or thick beam finite elements. The thin beam model uses the torsional spring beam formulation for small flexible vegetation and only includes the axial and bending beam responses. The thick beam model includes axial, bending, torsional, and shear beam responses and uses a lumped parameter beam element which connects two rigid body type nodes. The vegetation model includes the effects of normal contact and friction with the vehicle and between stems, stem breaking, and stem aerodynamic forces.
{"title":"Finite Element Model for Prediction of Ground Vehicle Mobility Over Vegetation Covered Terrains","authors":"T. Wasfy, Hatem M. Wasfy, P. Jayakumar, Srinivas Sanikommu","doi":"10.1115/detc2020-22764","DOIUrl":"https://doi.org/10.1115/detc2020-22764","url":null,"abstract":"\u0000 A finite element vegetation model is presented for predicting the dynamic interaction of ground vehicles with vegetation. The purpose of the model is to predict ground vehicle mobility over vegetation covered terrains. The types of vegetation can range from small diameter highly compliant stems to large stiff trees. Those include various types of vegetation such as grass, crops, shrubs/bushes, small trees, and large trees. Mobility measures which can be predicted include maximum safe vehicle speed along a specified path, tire slip, and fuel consumption. The ground vehicles are modeled using high-fidelity multibody dynamics models. The vegetation stems are modeled using an arrangement of thin and/or thick beam finite elements. The thin beam model uses the torsional spring beam formulation for small flexible vegetation and only includes the axial and bending beam responses. The thick beam model includes axial, bending, torsional, and shear beam responses and uses a lumped parameter beam element which connects two rigid body type nodes. The vegetation model includes the effects of normal contact and friction with the vehicle and between stems, stem breaking, and stem aerodynamic forces.","PeriodicalId":236538,"journal":{"name":"Volume 2: 16th International Conference on Multibody Systems, Nonlinear Dynamics, and Control (MSNDC)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124735352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jamal Ansary, J. O’Donnell, Nashiyat Fyza, B. Trease
Swarm robotic is a field of multi-robotics in which the robot’s behavior is inspired from nature. With rapid development in the field of the multi-robotics and the lack of efficacy in traditional centralized controls method, decentralized nature inspired swarm algorithms were introduced to control the swarm behavior. Unmanned surface vehicles (USVs) are marine crafts that they can operate autonomously. Due to their potential in operating in different areas, these vehicles have been used for variety of reason including patrolling, border protection, environmental monitoring and oil spill confrontation. This paper provides a review of the Swarm of USVs, their application, simulation environments and the algorithms that has been used in the past and current projects.
{"title":"Swarms of Aquatic Unmanned Surface Vehicles (USV), a Review From Simulation to Field Implementation","authors":"Jamal Ansary, J. O’Donnell, Nashiyat Fyza, B. Trease","doi":"10.1115/detc2020-22702","DOIUrl":"https://doi.org/10.1115/detc2020-22702","url":null,"abstract":"\u0000 Swarm robotic is a field of multi-robotics in which the robot’s behavior is inspired from nature. With rapid development in the field of the multi-robotics and the lack of efficacy in traditional centralized controls method, decentralized nature inspired swarm algorithms were introduced to control the swarm behavior. Unmanned surface vehicles (USVs) are marine crafts that they can operate autonomously. Due to their potential in operating in different areas, these vehicles have been used for variety of reason including patrolling, border protection, environmental monitoring and oil spill confrontation. This paper provides a review of the Swarm of USVs, their application, simulation environments and the algorithms that has been used in the past and current projects.","PeriodicalId":236538,"journal":{"name":"Volume 2: 16th International Conference on Multibody Systems, Nonlinear Dynamics, and Control (MSNDC)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126346700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Substructuring, or component mode synthesis, requires components to share interface regions. When components modeled with rather different, often incompatible levels of refinement need to be connected, correctly defining the interfaces may be important. This work proposes the definition of the reduction of interface regions to the equivalent rigid-body motion which minimizes the strain energy in the structural component. The proposed formulation provides a natural and physically sound solution for the connection of detailed structural components within coarse, multi-rigid-body and 1D flexible models.
{"title":"Compliant Interface in Component Mode Synthesis","authors":"P. Masarati, Fanny Darbas, I. Wander","doi":"10.1115/detc2020-22255","DOIUrl":"https://doi.org/10.1115/detc2020-22255","url":null,"abstract":"\u0000 Substructuring, or component mode synthesis, requires components to share interface regions. When components modeled with rather different, often incompatible levels of refinement need to be connected, correctly defining the interfaces may be important. This work proposes the definition of the reduction of interface regions to the equivalent rigid-body motion which minimizes the strain energy in the structural component. The proposed formulation provides a natural and physically sound solution for the connection of detailed structural components within coarse, multi-rigid-body and 1D flexible models.","PeriodicalId":236538,"journal":{"name":"Volume 2: 16th International Conference on Multibody Systems, Nonlinear Dynamics, and Control (MSNDC)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126989430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, the symmetric and asymmetric period-1 motions on the bifurcation tree are obtained for a periodically driven van der Pol-Duffing hardening oscillator through a semi-analytical method. Such a semi-analytical method develops an implicit mapping with prescribed accuracy. Based on the implicit mapping, the mapping structures are used to determine periodic motions in the van der Pol-Duffing oscillator. The symmetry breaks of period-1 motion are determined through saddle-node bifurcations, and the corresponding asymmetric period-1 motions are generated. The bifurcation and stability of period-1 motions are determined through eigenvalue analysis. To verify the semi-analytical solutions, numerical simulations are also carried out.
本文用半解析方法得到了周期驱动van der Pol-Duffing硬化振荡器在分岔树上的对称和非对称周期1运动。这种半解析方法发展了具有规定精度的隐式映射。在隐式映射的基础上，利用映射结构确定了van der Pol-Duffing振荡器的周期运动。通过鞍节点分岔确定周期1运动的对称性破缺，生成相应的非对称周期1运动。通过特征值分析确定了周期1运动的分岔性和稳定性。为了验证半解析解，还进行了数值模拟。
{"title":"On Periodic Motions in a Periodically Driven van der Pol-Duffing Oscillator","authors":"Yeyin Xu, A. Luo","doi":"10.1115/detc2020-22036","DOIUrl":"https://doi.org/10.1115/detc2020-22036","url":null,"abstract":"\u0000 In this paper, the symmetric and asymmetric period-1 motions on the bifurcation tree are obtained for a periodically driven van der Pol-Duffing hardening oscillator through a semi-analytical method. Such a semi-analytical method develops an implicit mapping with prescribed accuracy. Based on the implicit mapping, the mapping structures are used to determine periodic motions in the van der Pol-Duffing oscillator. The symmetry breaks of period-1 motion are determined through saddle-node bifurcations, and the corresponding asymmetric period-1 motions are generated. The bifurcation and stability of period-1 motions are determined through eigenvalue analysis. To verify the semi-analytical solutions, numerical simulations are also carried out.","PeriodicalId":236538,"journal":{"name":"Volume 2: 16th International Conference on Multibody Systems, Nonlinear Dynamics, and Control (MSNDC)","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124124189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The comprehensive simulation of flexible multibody systems calls for the ability to model various types of structural components such as rigid bodies, beams, plates, and kinematic joints. Modal components test offer additional modeling versatility by enabling the treatment of complex, three-dimensional structures via modal reduction procedures based on the small deformation assumption. In this paper, the problem is formulated within the framework of the motion formalism. The kinematic description involves simple, straightforward frame transformations and leads to deformation measures that are both objective and tensorial. Derivatives are expressed in the material frame, which results in the remarkable property that the tangent matrices are independent of the configuration of the modal component with respect to an inertial frame. This implies a reduced level of geometric nonlinearity as compared to standard description. In particular, geometrically nonlinear problems can be solved with the constant tangent matrices of the reference configuration, without re-evaluation and re-factorization.
{"title":"Modal Reduction Procedures for Flexible Multibody System Applications","authors":"Matteo Scapolan, M. Shan, O. Bauchau","doi":"10.1115/detc2020-22149","DOIUrl":"https://doi.org/10.1115/detc2020-22149","url":null,"abstract":"\u0000 The comprehensive simulation of flexible multibody systems calls for the ability to model various types of structural components such as rigid bodies, beams, plates, and kinematic joints. Modal components test offer additional modeling versatility by enabling the treatment of complex, three-dimensional structures via modal reduction procedures based on the small deformation assumption. In this paper, the problem is formulated within the framework of the motion formalism. The kinematic description involves simple, straightforward frame transformations and leads to deformation measures that are both objective and tensorial. Derivatives are expressed in the material frame, which results in the remarkable property that the tangent matrices are independent of the configuration of the modal component with respect to an inertial frame. This implies a reduced level of geometric nonlinearity as compared to standard description. In particular, geometrically nonlinear problems can be solved with the constant tangent matrices of the reference configuration, without re-evaluation and re-factorization.","PeriodicalId":236538,"journal":{"name":"Volume 2: 16th International Conference on Multibody Systems, Nonlinear Dynamics, and Control (MSNDC)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123706002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, the local and global dynamics of a periodically forced, quadratic-oscillator-based, infinite-equilibrium system is discussed. The local analysis of regular equilibriums and infinite-equilibriums is completed, and the global responses of the periodically forced infinite-equilibrium system are presented through numerical simulations. Near the infinite-equilibrium surface, the periodically forced infinite-equilibrium system can be reduced to a one-dimensional system and new contraction regions can be formed. The infinite-equilibrium surface can be artificially designed to control the motions of the original quadratic nonlinear oscillator. Such a property is like a discontinuous dynamical system, which can be used for controller design in nonlinear systems.
{"title":"On the Dynamics of a Quadratic-Oscillator-Based, Infinite-Equilibrium System","authors":"S. Xing, A. Luo, Jianzhe Huang","doi":"10.1115/detc2020-22233","DOIUrl":"https://doi.org/10.1115/detc2020-22233","url":null,"abstract":"\u0000 In this paper, the local and global dynamics of a periodically forced, quadratic-oscillator-based, infinite-equilibrium system is discussed. The local analysis of regular equilibriums and infinite-equilibriums is completed, and the global responses of the periodically forced infinite-equilibrium system are presented through numerical simulations. Near the infinite-equilibrium surface, the periodically forced infinite-equilibrium system can be reduced to a one-dimensional system and new contraction regions can be formed. The infinite-equilibrium surface can be artificially designed to control the motions of the original quadratic nonlinear oscillator. Such a property is like a discontinuous dynamical system, which can be used for controller design in nonlinear systems.","PeriodicalId":236538,"journal":{"name":"Volume 2: 16th International Conference on Multibody Systems, Nonlinear Dynamics, and Control (MSNDC)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126772811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A 4-DoF spatial mechanical model of trailers is used to analyze the snaking, rocking and roll-over motions. The derivation of the governing equations is presented. The non-smooth characteristics of the tire forces are taken into account together with other geometrical non-linearities. Beyond the linear stability analysis the nonlinear vibrations are investigated via numerical continuation and simulations. Linear stability charts and bifurcation diagrams are constructed to identify the parameter ranges, where large amplitude vibration can occur. The domains of the snaking and the rocking motion are detected. Numerical simulations verify the existence of periodic solutions predicted by numerical bifurcation analysis. A small scale experimental rig is presented and the nonlinear vibration of the trailer is investigated.
{"title":"Numerical and Experimental Bifurcation Analysis of Trailers","authors":"Hanna Zs. Horvath, D. Takács","doi":"10.1115/detc2020-22461","DOIUrl":"https://doi.org/10.1115/detc2020-22461","url":null,"abstract":"\u0000 A 4-DoF spatial mechanical model of trailers is used to analyze the snaking, rocking and roll-over motions. The derivation of the governing equations is presented. The non-smooth characteristics of the tire forces are taken into account together with other geometrical non-linearities. Beyond the linear stability analysis the nonlinear vibrations are investigated via numerical continuation and simulations. Linear stability charts and bifurcation diagrams are constructed to identify the parameter ranges, where large amplitude vibration can occur. The domains of the snaking and the rocking motion are detected. Numerical simulations verify the existence of periodic solutions predicted by numerical bifurcation analysis. A small scale experimental rig is presented and the nonlinear vibration of the trailer is investigated.","PeriodicalId":236538,"journal":{"name":"Volume 2: 16th International Conference on Multibody Systems, Nonlinear Dynamics, and Control (MSNDC)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117253042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The aim of this study is to highlight nonlinear behaviors and periodic orbits of the single-track vehicle model with a delayed feedback controller. Two widely used tire models, namely a linear tire characteristic and Pacejka’s Magic Formula are considered. Linearly stable domains of parameters such as the vehicle speed and the control gains are determined. Periodic solutions originating from Hopf bifurcation points are followed using numerical continuation and the results obtained with the two different tire models are compared. It is shown that neglecting the saturation of the tire lateral forces at total sliding might change the sense of certain Hopf bifurcations from subcritical to supercritical. The results are verified by numerical simulations. The resulting bifurcation diagrams aim to quantify the degree of robustness of these controllers with regards to the initial conditions at various parameter ranges in order to assure stable and safe operation.
{"title":"Bifurcation Analysis of a Lane Keeping Controller With Feedback Delay","authors":"Illés Vörös, D. Takács","doi":"10.1115/detc2020-22387","DOIUrl":"https://doi.org/10.1115/detc2020-22387","url":null,"abstract":"\u0000 The aim of this study is to highlight nonlinear behaviors and periodic orbits of the single-track vehicle model with a delayed feedback controller. Two widely used tire models, namely a linear tire characteristic and Pacejka’s Magic Formula are considered. Linearly stable domains of parameters such as the vehicle speed and the control gains are determined. Periodic solutions originating from Hopf bifurcation points are followed using numerical continuation and the results obtained with the two different tire models are compared. It is shown that neglecting the saturation of the tire lateral forces at total sliding might change the sense of certain Hopf bifurcations from subcritical to supercritical. The results are verified by numerical simulations. The resulting bifurcation diagrams aim to quantify the degree of robustness of these controllers with regards to the initial conditions at various parameter ranges in order to assure stable and safe operation.","PeriodicalId":236538,"journal":{"name":"Volume 2: 16th International Conference on Multibody Systems, Nonlinear Dynamics, and Control (MSNDC)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129992561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Principal parametric resonances of elastic plates actuated by periodic in-plane stresses effected by embedded piezoelectric wires are investigated to describe the morphing scenarios of flexible, ultra-lightweight panels. A mechanical model of elastic plate including geometric nonlinearities and the parametric actuation provided by the piezoelectric wires, is adopted to formulate the nonlinear equation of motion. A bifurcation analysis is carried out by means of an asymptotic approach based on the method of multiple scales leading to a comprehensive parametric study on the effect of the wires width on the morphing regions (i.e., parametric instability regions) associated with the principal parametric resonances. The threshold voltages triggering the onset of the principal parametric resonances of the lowest three symmetric modes are also calculated as a function of the wires size so as to determine the voltage requirements for the morphing activation.
{"title":"Dynamic Morphing of Elastic Plates via Principal Parametric Resonance","authors":"A. Arena, W. Lacarbonara","doi":"10.1115/detc2020-22470","DOIUrl":"https://doi.org/10.1115/detc2020-22470","url":null,"abstract":"\u0000 Principal parametric resonances of elastic plates actuated by periodic in-plane stresses effected by embedded piezoelectric wires are investigated to describe the morphing scenarios of flexible, ultra-lightweight panels. A mechanical model of elastic plate including geometric nonlinearities and the parametric actuation provided by the piezoelectric wires, is adopted to formulate the nonlinear equation of motion. A bifurcation analysis is carried out by means of an asymptotic approach based on the method of multiple scales leading to a comprehensive parametric study on the effect of the wires width on the morphing regions (i.e., parametric instability regions) associated with the principal parametric resonances. The threshold voltages triggering the onset of the principal parametric resonances of the lowest three symmetric modes are also calculated as a function of the wires size so as to determine the voltage requirements for the morphing activation.","PeriodicalId":236538,"journal":{"name":"Volume 2: 16th International Conference on Multibody Systems, Nonlinear Dynamics, and Control (MSNDC)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128104479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The conventional continuum-mechanics-based floating frame of reference formulation involves unhandy so-called inertia-shape-integrals in the equations of motion, which is why, commercial multibody software codes resort to a lumped mass approximation to avoid the evaluation of these integrals in their computer implementations. This paper recaps the conventional continuum mechanics floating frame of reference formulation and addresses its drawbacks by summarizing recent developments of the so-called nodal-based floating frame of reference formulation, which avoids inertia shape integrals ab initio, does not rely on a lumped mass approximation, and exhibits a way to calculate the so-called invariants, which are constant “ingredients” required to set up the equations of motion, in a consistent way.
{"title":"Consistent and Inertia-Shape-Integral-Free Invariants of the Floating Frame of Reference Formulation","authors":"Andreas Zwölfer, J. Gerstmayr","doi":"10.1115/detc2020-22293","DOIUrl":"https://doi.org/10.1115/detc2020-22293","url":null,"abstract":"\u0000 The conventional continuum-mechanics-based floating frame of reference formulation involves unhandy so-called inertia-shape-integrals in the equations of motion, which is why, commercial multibody software codes resort to a lumped mass approximation to avoid the evaluation of these integrals in their computer implementations. This paper recaps the conventional continuum mechanics floating frame of reference formulation and addresses its drawbacks by summarizing recent developments of the so-called nodal-based floating frame of reference formulation, which avoids inertia shape integrals ab initio, does not rely on a lumped mass approximation, and exhibits a way to calculate the so-called invariants, which are constant “ingredients” required to set up the equations of motion, in a consistent way.","PeriodicalId":236538,"journal":{"name":"Volume 2: 16th International Conference on Multibody Systems, Nonlinear Dynamics, and Control (MSNDC)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125477841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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