Pub Date : 1900-01-01DOI: 10.3311/eccomasmbd2021-199
G. Boschetti, F. González, G. Piva, D. Richiedei, Borja Rodríguez Frade, A. Trevisani
Cable-driven parallel robots are light-weight parallel robots where cables replace rigid actuators to move an end-effector. As a consequence, they have large workspaces, high-dynamic handlings, ease of reconfigurability and/or low-cost architecture. Knowing the full state variables of the robot model is usually useful for control and monitoring; however, it is often not directly measured and therefore the development of state observers is essential. In this work a general approach to develop a nonlinear state observer based on an Extended Kalman Filter is proposed and validated numerically by referring to a cable-suspended parallel robot. The state observer is based on a system model obtained converting a set of Differential Algebraic Equations into Ordinary Differential Equations through two different methods: the penalty formulation and the Udwadia-Kalaba formulation.
{"title":"Synthesis of an Extended Kalman Filter for Cable-Driven Parallel Robots","authors":"G. Boschetti, F. González, G. Piva, D. Richiedei, Borja Rodríguez Frade, A. Trevisani","doi":"10.3311/eccomasmbd2021-199","DOIUrl":"https://doi.org/10.3311/eccomasmbd2021-199","url":null,"abstract":"Cable-driven parallel robots are light-weight parallel robots where cables replace rigid actuators to move an end-effector. As a consequence, they have large workspaces, high-dynamic handlings, ease of reconfigurability and/or low-cost architecture. Knowing the full state variables of the robot model is usually useful for control and monitoring; however, it is often not directly measured and therefore the development of state observers is essential. In this work a general approach to develop a nonlinear state observer based on an Extended Kalman Filter is proposed and validated numerically by referring to a cable-suspended parallel robot. The state observer is based on a system model obtained converting a set of Differential Algebraic Equations into Ordinary Differential Equations through two different methods: the penalty formulation and the Udwadia-Kalaba formulation.","PeriodicalId":431921,"journal":{"name":"Proceedings of the 10th ECCOMAS Thematic Conference on MULTIBODY DYNAMICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125610057","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}
Pub Date : 1900-01-01DOI: 10.3311/eccomasmbd2021-203
Veit Gufler, E. Wehrle, J. Achleitner, R. Vidoni
{"title":"Flexible Multibody Dynamics and Sensitivity Analysis in the Design of a Morphing Leading Edge for High-Performance Sailplanes","authors":"Veit Gufler, E. Wehrle, J. Achleitner, R. Vidoni","doi":"10.3311/eccomasmbd2021-203","DOIUrl":"https://doi.org/10.3311/eccomasmbd2021-203","url":null,"abstract":"","PeriodicalId":431921,"journal":{"name":"Proceedings of the 10th ECCOMAS Thematic Conference on MULTIBODY DYNAMICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121419277","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}
Pub Date : 1900-01-01DOI: 10.3311/eccomasmbd2021-153
T. Ströhle, P. Betsch
{"title":"Simultaneous Space-Time Discretization for Controlling the Motion of Rigid Bodies Actuated Through Elastic Ropes","authors":"T. Ströhle, P. Betsch","doi":"10.3311/eccomasmbd2021-153","DOIUrl":"https://doi.org/10.3311/eccomasmbd2021-153","url":null,"abstract":"","PeriodicalId":431921,"journal":{"name":"Proceedings of the 10th ECCOMAS Thematic Conference on MULTIBODY DYNAMICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121321095","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}
Pub Date : 1900-01-01DOI: 10.3311/eccomasmbd2021-206
A. Finozzi, F. Sanfedino, D. Alazard
In the context of multi-body modeling techniques, this paper introduces a new analytical approach to build a Two-Input-Two-Output Port (TITOP) model for a clamped-clamped flexible appendage. By expanding the previous work found in literature, which relied on numerical procedures, this model represents a fundamental block for the construction of parametric multi-body systems in a sub-structuring approach, such as closed-loop kinematic mechanisms. Specifically, this new procedure allows to assemble a linear state-space system by analytically inversing the input-output channels of the original clamped-free TITOP model. This analytical method presents the advantage of avoiding non-physical behaviors introduced by numerical inversions as well as removing the need to reduce the quasi-zero poles associated with the nonanalytical model. This paper presents the mathematical formulation of the system, as well as the formalism behind the method, and an illustrative case study to showcase the advantages of this approach.
{"title":"Analytical Port Inversion For A Flexible Model In The Two-Input Two-Output Port Approach","authors":"A. Finozzi, F. Sanfedino, D. Alazard","doi":"10.3311/eccomasmbd2021-206","DOIUrl":"https://doi.org/10.3311/eccomasmbd2021-206","url":null,"abstract":"In the context of multi-body modeling techniques, this paper introduces a new analytical approach to build a Two-Input-Two-Output Port (TITOP) model for a clamped-clamped flexible appendage. By expanding the previous work found in literature, which relied on numerical procedures, this model represents a fundamental block for the construction of parametric multi-body systems in a sub-structuring approach, such as closed-loop kinematic mechanisms. Specifically, this new procedure allows to assemble a linear state-space system by analytically inversing the input-output channels of the original clamped-free TITOP model. This analytical method presents the advantage of avoiding non-physical behaviors introduced by numerical inversions as well as removing the need to reduce the quasi-zero poles associated with the nonanalytical model. This paper presents the mathematical formulation of the system, as well as the formalism behind the method, and an illustrative case study to showcase the advantages of this approach.","PeriodicalId":431921,"journal":{"name":"Proceedings of the 10th ECCOMAS Thematic Conference on MULTIBODY DYNAMICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126867256","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}
Pub Date : 1900-01-01DOI: 10.3311/eccomasmbd2021-161
G. Schneider, P. Schmid, F. Dignath, P. Eberhard
{"title":"Modeling and Simulation of a High-speed Maglev Vehicle on an Infinite Elastic Guideway","authors":"G. Schneider, P. Schmid, F. Dignath, P. Eberhard","doi":"10.3311/eccomasmbd2021-161","DOIUrl":"https://doi.org/10.3311/eccomasmbd2021-161","url":null,"abstract":"","PeriodicalId":431921,"journal":{"name":"Proceedings of the 10th ECCOMAS Thematic Conference on MULTIBODY DYNAMICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122665405","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}
Pub Date : 1900-01-01DOI: 10.3311/eccomasmbd2021-196
Michael Tahedl, F. Borchsenius, A. Taras
{"title":"Efficient earthquake simulation of stiff and high DOF bridge expansion joint models with Python","authors":"Michael Tahedl, F. Borchsenius, A. Taras","doi":"10.3311/eccomasmbd2021-196","DOIUrl":"https://doi.org/10.3311/eccomasmbd2021-196","url":null,"abstract":"","PeriodicalId":431921,"journal":{"name":"Proceedings of the 10th ECCOMAS Thematic Conference on MULTIBODY DYNAMICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121826375","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}
Pub Date : 1900-01-01DOI: 10.3311/eccomasmbd2021-130
S. Schneider, P. Betsch
The focus of this work is on optimal control in redundant coordinates with a special attention to the boundary constraints that arise in this context. Due to the similarity of the optimization problem of optimal control to the Lagrangian formalism of classical mechanics, this is considered first. Once the mechanical problem of the boundary conditions in redundant coordinates has been discussed, the knowledge gained is transferred to the optimal control problem in order to solve the problem in redundant coordinates. Finally, for each section the equivalence of the problem in minimal coordinates and redundant coordinates is shown by numerical results.
{"title":"On the Dynamics and Optimal Control of Constrained Mechanical Systems","authors":"S. Schneider, P. Betsch","doi":"10.3311/eccomasmbd2021-130","DOIUrl":"https://doi.org/10.3311/eccomasmbd2021-130","url":null,"abstract":"The focus of this work is on optimal control in redundant coordinates with a special attention to the boundary constraints that arise in this context. Due to the similarity of the optimization problem of optimal control to the Lagrangian formalism of classical mechanics, this is considered first. Once the mechanical problem of the boundary conditions in redundant coordinates has been discussed, the knowledge gained is transferred to the optimal control problem in order to solve the problem in redundant coordinates. Finally, for each section the equivalence of the problem in minimal coordinates and redundant coordinates is shown by numerical results.","PeriodicalId":431921,"journal":{"name":"Proceedings of the 10th ECCOMAS Thematic Conference on MULTIBODY DYNAMICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116516498","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}
Pub Date : 1900-01-01DOI: 10.3311/eccomasmbd2021-226
B. Bauer, Michael Roller, J. Linn, B. Simeon
The goal of this paper is to introduce a kinematical reduction for the structural model of Kirchhoff-Love shells with developable base surfaces. The dimensional reduction to a curve and a vector field along it decreases the involved number of degrees of freedom. Local coordinates in form of a relatively parallel frame allow us to simplify the geometric constraints occurring in the model and prevent instabilities caused by points or segments of zero curvature. The core of this work is to prove equivalence of these requirements and the isometry of the transformation. Subsequently, we derive the one-dimensional bending energy functional for rectangular strips. In order to compute the equilibrium state of a static shell, we minimise a penalised version of this functional over the finitely many degrees of freedom stemming from an isogeometric discretisation. Several example strips clamped at both ends illustrate the feasibility of this approach.
{"title":"One-Dimensional Modelling of Developable Elastic Strips by Geometric Constraints and their Link to Surface Isometry","authors":"B. Bauer, Michael Roller, J. Linn, B. Simeon","doi":"10.3311/eccomasmbd2021-226","DOIUrl":"https://doi.org/10.3311/eccomasmbd2021-226","url":null,"abstract":"The goal of this paper is to introduce a kinematical reduction for the structural model of Kirchhoff-Love shells with developable base surfaces. The dimensional reduction to a curve and a vector field along it decreases the involved number of degrees of freedom. Local coordinates in form of a relatively parallel frame allow us to simplify the geometric constraints occurring in the model and prevent instabilities caused by points or segments of zero curvature. The core of this work is to prove equivalence of these requirements and the isometry of the transformation. Subsequently, we derive the one-dimensional bending energy functional for rectangular strips. In order to compute the equilibrium state of a static shell, we minimise a penalised version of this functional over the finitely many degrees of freedom stemming from an isogeometric discretisation. Several example strips clamped at both ends illustrate the feasibility of this approach.","PeriodicalId":431921,"journal":{"name":"Proceedings of the 10th ECCOMAS Thematic Conference on MULTIBODY DYNAMICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134311749","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}
Pub Date : 1900-01-01DOI: 10.3311/eccomasmbd2021-218
K. Dwarshuis, M. Nijenhuis, R. Aarts, M. Ellenbroek, D. Brouwer
The computation of stress in beam elements requires the internal stress resultants like axial force and bending moments. For displacement-based beam elements, these resultants can be obtained 1) based on equilibrium, 2) consistent to the constitutive law or 3) based on load interpolation functions. Although the methods give similar results in case of small deformation, the discrepancies in case of large deformation are significant. This paper shows that the method based on equilibrium gives the most accurate results. Torsion of beam elements causes warping of the cross section. This warping is constrained at clamped ends of beam elements, causing extra stress. This paper shows a method to accurately obtain the corresponding internal stress resultants, i.e. the Saint-Venant torsion moment and bimoment.
{"title":"Computation of internal stress resultants in beam elements with constrained torsional warping","authors":"K. Dwarshuis, M. Nijenhuis, R. Aarts, M. Ellenbroek, D. Brouwer","doi":"10.3311/eccomasmbd2021-218","DOIUrl":"https://doi.org/10.3311/eccomasmbd2021-218","url":null,"abstract":"The computation of stress in beam elements requires the internal stress resultants like axial force and bending moments. For displacement-based beam elements, these resultants can be obtained 1) based on equilibrium, 2) consistent to the constitutive law or 3) based on load interpolation functions. Although the methods give similar results in case of small deformation, the discrepancies in case of large deformation are significant. This paper shows that the method based on equilibrium gives the most accurate results. Torsion of beam elements causes warping of the cross section. This warping is constrained at clamped ends of beam elements, causing extra stress. This paper shows a method to accurately obtain the corresponding internal stress resultants, i.e. the Saint-Venant torsion moment and bimoment.","PeriodicalId":431921,"journal":{"name":"Proceedings of the 10th ECCOMAS Thematic Conference on MULTIBODY DYNAMICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134325337","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}
Pub Date : 1900-01-01DOI: 10.3311/eccomasmbd2021-152
K. Osman, Trpimir Alajbeg
This paper presents the research of a hexapod robot as it movement along a defined path. Firstly, the performance of the robot product architecture is presented and a mathematical kinematic model of the robot is derived according to it, i.e. its legs using the Denavit-Hartenberg method and homogeneous transformations. The purpose of this was to obtain the equations of inverse kinematics. A simplified robot product architecture based on rectangular robot design was used to perform the mathematical model. It is shown by a simplified kinematic scheme. In addition, a control algorithm was performed using a PID controller in each ankle. The controller’s parameters are adjusted on one leg of the robot, and after that, this is used to adjust the control on the other legs in this way. The simulation of the controlled motion of the robot was performed using the computer program MATLAB Simulink and the Simscape Multibody environment. In doing so, only the robot's movement on flat terrain was observed. The tripod gait was chosen for the motion model due to the simplicity of creating the model and performing the simulation, as well as the speed of movement.
{"title":"Mathematical Model and Control Simulation of Hexapod Robot Locomotion in Tripod Gait","authors":"K. Osman, Trpimir Alajbeg","doi":"10.3311/eccomasmbd2021-152","DOIUrl":"https://doi.org/10.3311/eccomasmbd2021-152","url":null,"abstract":"This paper presents the research of a hexapod robot as it movement along a defined path. Firstly, the performance of the robot product architecture is presented and a mathematical kinematic model of the robot is derived according to it, i.e. its legs using the Denavit-Hartenberg method and homogeneous transformations. The purpose of this was to obtain the equations of inverse kinematics. A simplified robot product architecture based on rectangular robot design was used to perform the mathematical model. It is shown by a simplified kinematic scheme. In addition, a control algorithm was performed using a PID controller in each ankle. The controller’s parameters are adjusted on one leg of the robot, and after that, this is used to adjust the control on the other legs in this way. The simulation of the controlled motion of the robot was performed using the computer program MATLAB Simulink and the Simscape Multibody environment. In doing so, only the robot's movement on flat terrain was observed. The tripod gait was chosen for the motion model due to the simplicity of creating the model and performing the simulation, as well as the speed of movement.","PeriodicalId":431921,"journal":{"name":"Proceedings of the 10th ECCOMAS Thematic Conference on MULTIBODY DYNAMICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130032032","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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