The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Glaucio H Paulino - One of the best experts on this subject based on the ideXlab platform.
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the Simple Boundary element method for multiple cracks in functionally graded media governed by potential theory a three dimensional galerkin approach
International Journal for Numerical Methods in Engineering, 2006Co-Authors: Glaucio H Paulino, Alok SutradharAbstract:The Simple Boundary element method consists of recycling existing codes for homogeneous media to solve problems in non-homogeneous media while maintaining a purely Boundary-only formulation. Within this scope, this paper presents a ‘Simple’ Galerkin Boundary element method for multiple cracks in problems governed by potential theory in functionally graded media. Steady-state heat conduction is investigated for thermal conductivity varying either parabolically, exponentially, or trigonometrically in one or more co-ordinates. A three-dimensional implementation which merges the dual Boundary integral equation technique with the Galerkin approach is presented. Special emphasis is given to the treatment of crack surfaces and Boundary conditions. The test examples simulated with the present method are verified with finite element results using graded finite elements. The numerical examples demonstrate the accuracy and efficiency of the present method especially when multiple interacting cracks are involved. Copyright © 2005 John Wiley & Sons, Ltd.
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the Simple Boundary element method for transient heat conduction in functionally graded materials
Computer Methods in Applied Mechanics and Engineering, 2004Co-Authors: Alok Sutradhar, Glaucio H PaulinoAbstract:Abstract This paper presents a “Simple” Boundary element method for transient heat conduction in functionally graded materials, which leads to a Boundary-only formulation without any domain discretization. For a broad range of functional material variation (quadratic, exponential and trigonometric) of thermal conductivity and specific heat, the non-homogeneous problem can be transformed into the standard homogeneous diffusion problem. A three-dimensional Boundary element implementation, using the Laplace transform approach and the Galerkin approximation, is presented. The time dependence is restored by numerically inverting the Laplace transform by means of the Stehfest algorithm. A number of numerical examples demonstrate the efficiency of the method. The results of the test examples are in excellent agreement with analytical solutions and finite element simulation results.
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a Simple Boundary element method for problems of potential in non homogeneous media
International Journal for Numerical Methods in Engineering, 2004Co-Authors: Alok Sutradhar, Glaucio H PaulinoAbstract:A Simple Boundary element method for solving potential problems in non-homogeneous media is presented. A physical parameter (e.g. heat conductivity, permeability, permittivity, resistivity, magnetic permeability) has a spatial distribution that varies with one or more co-ordinates. For certain classes of material variations the non-homogeneous problem can be transformed to known homogeneous problems such as those governed by the Laplace, Helmholtz and modified Helmholtz equations. A three-dimensional Galerkin Boundary element method implementation is presented for these cases. However, the present development is not restricted to Galerkin schemes and can be readily extended to other Boundary integral methods such as standard collocation. A few test examples are given to verify the proposed formulation. The paper is supplemented by an Appendix, which presents an ABAQUS user-subroutine for graded finite elements. The results from the finite element simulations are used for comparison with the present Boundary element solutions.
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A Simple Boundary element method for problems of potential in non‐homogeneous media
International Journal for Numerical Methods in Engineering, 2004Co-Authors: Alok Sutradhar, Glaucio H PaulinoAbstract:A Simple Boundary element method for solving potential problems in non-homogeneous media is presented. A physical parameter (e.g. heat conductivity, permeability, permittivity, resistivity, magnetic permeability) has a spatial distribution that varies with one or more co-ordinates. For certain classes of material variations the non-homogeneous problem can be transformed to known homogeneous problems such as those governed by the Laplace, Helmholtz and modified Helmholtz equations. A three-dimensional Galerkin Boundary element method implementation is presented for these cases. However, the present development is not restricted to Galerkin schemes and can be readily extended to other Boundary integral methods such as standard collocation. A few test examples are given to verify the proposed formulation. The paper is supplemented by an Appendix, which presents an ABAQUS user-subroutine for graded finite elements. The results from the finite element simulations are used for comparison with the present Boundary element solutions.
Alok Sutradhar - One of the best experts on this subject based on the ideXlab platform.
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the Simple Boundary element method for multiple cracks in functionally graded media governed by potential theory a three dimensional galerkin approach
International Journal for Numerical Methods in Engineering, 2006Co-Authors: Glaucio H Paulino, Alok SutradharAbstract:The Simple Boundary element method consists of recycling existing codes for homogeneous media to solve problems in non-homogeneous media while maintaining a purely Boundary-only formulation. Within this scope, this paper presents a ‘Simple’ Galerkin Boundary element method for multiple cracks in problems governed by potential theory in functionally graded media. Steady-state heat conduction is investigated for thermal conductivity varying either parabolically, exponentially, or trigonometrically in one or more co-ordinates. A three-dimensional implementation which merges the dual Boundary integral equation technique with the Galerkin approach is presented. Special emphasis is given to the treatment of crack surfaces and Boundary conditions. The test examples simulated with the present method are verified with finite element results using graded finite elements. The numerical examples demonstrate the accuracy and efficiency of the present method especially when multiple interacting cracks are involved. Copyright © 2005 John Wiley & Sons, Ltd.
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the Simple Boundary element method for transient heat conduction in functionally graded materials
Computer Methods in Applied Mechanics and Engineering, 2004Co-Authors: Alok Sutradhar, Glaucio H PaulinoAbstract:Abstract This paper presents a “Simple” Boundary element method for transient heat conduction in functionally graded materials, which leads to a Boundary-only formulation without any domain discretization. For a broad range of functional material variation (quadratic, exponential and trigonometric) of thermal conductivity and specific heat, the non-homogeneous problem can be transformed into the standard homogeneous diffusion problem. A three-dimensional Boundary element implementation, using the Laplace transform approach and the Galerkin approximation, is presented. The time dependence is restored by numerically inverting the Laplace transform by means of the Stehfest algorithm. A number of numerical examples demonstrate the efficiency of the method. The results of the test examples are in excellent agreement with analytical solutions and finite element simulation results.
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a Simple Boundary element method for problems of potential in non homogeneous media
International Journal for Numerical Methods in Engineering, 2004Co-Authors: Alok Sutradhar, Glaucio H PaulinoAbstract:A Simple Boundary element method for solving potential problems in non-homogeneous media is presented. A physical parameter (e.g. heat conductivity, permeability, permittivity, resistivity, magnetic permeability) has a spatial distribution that varies with one or more co-ordinates. For certain classes of material variations the non-homogeneous problem can be transformed to known homogeneous problems such as those governed by the Laplace, Helmholtz and modified Helmholtz equations. A three-dimensional Galerkin Boundary element method implementation is presented for these cases. However, the present development is not restricted to Galerkin schemes and can be readily extended to other Boundary integral methods such as standard collocation. A few test examples are given to verify the proposed formulation. The paper is supplemented by an Appendix, which presents an ABAQUS user-subroutine for graded finite elements. The results from the finite element simulations are used for comparison with the present Boundary element solutions.
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A Simple Boundary element method for problems of potential in non‐homogeneous media
International Journal for Numerical Methods in Engineering, 2004Co-Authors: Alok Sutradhar, Glaucio H PaulinoAbstract:A Simple Boundary element method for solving potential problems in non-homogeneous media is presented. A physical parameter (e.g. heat conductivity, permeability, permittivity, resistivity, magnetic permeability) has a spatial distribution that varies with one or more co-ordinates. For certain classes of material variations the non-homogeneous problem can be transformed to known homogeneous problems such as those governed by the Laplace, Helmholtz and modified Helmholtz equations. A three-dimensional Galerkin Boundary element method implementation is presented for these cases. However, the present development is not restricted to Galerkin schemes and can be readily extended to other Boundary integral methods such as standard collocation. A few test examples are given to verify the proposed formulation. The paper is supplemented by an Appendix, which presents an ABAQUS user-subroutine for graded finite elements. The results from the finite element simulations are used for comparison with the present Boundary element solutions.
Fumitoshi Matsuno - One of the best experts on this subject based on the ideXlab platform.
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Contact-Force Control of a Flexible Timoshenko Arm
IEEE Transactions on Automatic Control, 2017Co-Authors: Takahiro Endo, Minoru Sasaki, Fumitoshi MatsunoAbstract:This technical note discusses a contact-force control problem for a flexible arm. This flexible arm includes a Timoshenko beam, and thus we call it the flexible Timoshenko arm. The aim of the force control is to control the contact force at the contact point. To solve this problem, we propose a Simple Boundary controller and show the exponential stability of the closed-loop system by the frequency domain method. Finally, we describe simulation results carried out to investigate the validity of the proposed controller for the force control problem.
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Simple Boundary Cooperative Control of Two One-Link Flexible Arms for Grasping
IEEE Transactions on Automatic Control, 2009Co-Authors: Takahiro Endo, Fumitoshi Matsuno, Haruhisa KawasakiAbstract:This paper considers a grasping task by means of two one-link flexible arms. To accomplish this task, we propose a Simple Boundary cooperative control based on a dynamic model, which consists of partial differential equations (PDEs) and ordinary differential equations (ODEs) subject to geometric constraints. Since the data which is needed for the implementation of the controller can be obtained by a strain gauge and a rotary encoder, it is easy to implement it. The asymptotic stability of a closed-loop system and the exponential stability of the system under some conditions are studied.
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CCA - Simple Boundary control of two one-link flexible arms for grasping
2007 IEEE International Conference on Control Applications, 2007Co-Authors: Takahiro Endo, Fumitoshi Matsuno, Haruhisa KawasakiAbstract:This paper is concerned with a grasping task by means of two one-link flexible arms. To accomplish this task, we propose Simple Boundary control based on the dynamic model, which consists of partial differential equations (PDEs) and ordinary differential equations (ODEs) subject to the geometric constraints. Since the data, which is needed in the implementation of the controller, can be obtained by the strain gauge and the rotary encoder, it is easy to implement the controller. Furthermore, the controller is derived based on the original infinite dimensional model, and the stability of the closed-loop system is given by using the semigroup theory and the LaSalle's invariance principle which is extended to the infinite dimensional systems. Thus we can avoid the drawbacks resulting from the finite dimensional approximation.
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Simple Boundary control of two one-link flexible arms for grasping
2007 IEEE International Conference on Control Applications, 2007Co-Authors: Takahiro Endo, Fumitoshi Matsuno, Haruhisa KawasakiAbstract:This paper is concerned with a grasping task by means of two one-link flexible arms. To accomplish this task, we propose Simple Boundary control based on the dynamic model, which consists of partial differential equations (PDEs) and ordinary differential equations (ODEs) subject to the geometric constraints. Since the data, which is needed in the implementation of the controller, can be obtained by the strain gauge and the rotary encoder, it is easy to implement the controller. Furthermore, the controller is derived based on the original infinite dimensional model, and the stability of the closed-loop system is given by using the semigroup theory and the LaSalle's invariance principle which is extended to the infinite dimensional systems. Thus we can avoid the drawbacks resulting from the finite dimensional approximation.
Takahiro Endo - One of the best experts on this subject based on the ideXlab platform.
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Contact-Force Control of a Flexible Timoshenko Arm
IEEE Transactions on Automatic Control, 2017Co-Authors: Takahiro Endo, Minoru Sasaki, Fumitoshi MatsunoAbstract:This technical note discusses a contact-force control problem for a flexible arm. This flexible arm includes a Timoshenko beam, and thus we call it the flexible Timoshenko arm. The aim of the force control is to control the contact force at the contact point. To solve this problem, we propose a Simple Boundary controller and show the exponential stability of the closed-loop system by the frequency domain method. Finally, we describe simulation results carried out to investigate the validity of the proposed controller for the force control problem.
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Simple Boundary Cooperative Control of Two One-Link Flexible Arms for Grasping
IEEE Transactions on Automatic Control, 2009Co-Authors: Takahiro Endo, Fumitoshi Matsuno, Haruhisa KawasakiAbstract:This paper considers a grasping task by means of two one-link flexible arms. To accomplish this task, we propose a Simple Boundary cooperative control based on a dynamic model, which consists of partial differential equations (PDEs) and ordinary differential equations (ODEs) subject to geometric constraints. Since the data which is needed for the implementation of the controller can be obtained by a strain gauge and a rotary encoder, it is easy to implement it. The asymptotic stability of a closed-loop system and the exponential stability of the system under some conditions are studied.
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CCA - Simple Boundary control of two one-link flexible arms for grasping
2007 IEEE International Conference on Control Applications, 2007Co-Authors: Takahiro Endo, Fumitoshi Matsuno, Haruhisa KawasakiAbstract:This paper is concerned with a grasping task by means of two one-link flexible arms. To accomplish this task, we propose Simple Boundary control based on the dynamic model, which consists of partial differential equations (PDEs) and ordinary differential equations (ODEs) subject to the geometric constraints. Since the data, which is needed in the implementation of the controller, can be obtained by the strain gauge and the rotary encoder, it is easy to implement the controller. Furthermore, the controller is derived based on the original infinite dimensional model, and the stability of the closed-loop system is given by using the semigroup theory and the LaSalle's invariance principle which is extended to the infinite dimensional systems. Thus we can avoid the drawbacks resulting from the finite dimensional approximation.
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Simple Boundary control of two one-link flexible arms for grasping
2007 IEEE International Conference on Control Applications, 2007Co-Authors: Takahiro Endo, Fumitoshi Matsuno, Haruhisa KawasakiAbstract:This paper is concerned with a grasping task by means of two one-link flexible arms. To accomplish this task, we propose Simple Boundary control based on the dynamic model, which consists of partial differential equations (PDEs) and ordinary differential equations (ODEs) subject to the geometric constraints. Since the data, which is needed in the implementation of the controller, can be obtained by the strain gauge and the rotary encoder, it is easy to implement the controller. Furthermore, the controller is derived based on the original infinite dimensional model, and the stability of the closed-loop system is given by using the semigroup theory and the LaSalle's invariance principle which is extended to the infinite dimensional systems. Thus we can avoid the drawbacks resulting from the finite dimensional approximation.
Haruhisa Kawasaki - One of the best experts on this subject based on the ideXlab platform.
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Simple Boundary Cooperative Control of Two One-Link Flexible Arms for Grasping
IEEE Transactions on Automatic Control, 2009Co-Authors: Takahiro Endo, Fumitoshi Matsuno, Haruhisa KawasakiAbstract:This paper considers a grasping task by means of two one-link flexible arms. To accomplish this task, we propose a Simple Boundary cooperative control based on a dynamic model, which consists of partial differential equations (PDEs) and ordinary differential equations (ODEs) subject to geometric constraints. Since the data which is needed for the implementation of the controller can be obtained by a strain gauge and a rotary encoder, it is easy to implement it. The asymptotic stability of a closed-loop system and the exponential stability of the system under some conditions are studied.
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CCA - Simple Boundary control of two one-link flexible arms for grasping
2007 IEEE International Conference on Control Applications, 2007Co-Authors: Takahiro Endo, Fumitoshi Matsuno, Haruhisa KawasakiAbstract:This paper is concerned with a grasping task by means of two one-link flexible arms. To accomplish this task, we propose Simple Boundary control based on the dynamic model, which consists of partial differential equations (PDEs) and ordinary differential equations (ODEs) subject to the geometric constraints. Since the data, which is needed in the implementation of the controller, can be obtained by the strain gauge and the rotary encoder, it is easy to implement the controller. Furthermore, the controller is derived based on the original infinite dimensional model, and the stability of the closed-loop system is given by using the semigroup theory and the LaSalle's invariance principle which is extended to the infinite dimensional systems. Thus we can avoid the drawbacks resulting from the finite dimensional approximation.
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Simple Boundary control of two one-link flexible arms for grasping
2007 IEEE International Conference on Control Applications, 2007Co-Authors: Takahiro Endo, Fumitoshi Matsuno, Haruhisa KawasakiAbstract:This paper is concerned with a grasping task by means of two one-link flexible arms. To accomplish this task, we propose Simple Boundary control based on the dynamic model, which consists of partial differential equations (PDEs) and ordinary differential equations (ODEs) subject to the geometric constraints. Since the data, which is needed in the implementation of the controller, can be obtained by the strain gauge and the rotary encoder, it is easy to implement the controller. Furthermore, the controller is derived based on the original infinite dimensional model, and the stability of the closed-loop system is given by using the semigroup theory and the LaSalle's invariance principle which is extended to the infinite dimensional systems. Thus we can avoid the drawbacks resulting from the finite dimensional approximation.
