The Experts below are selected from a list of 186 Experts worldwide ranked by ideXlab platform

Teresa Headgordon - One of the best experts on this subject based on the ideXlab platform.

  • stochastic constrained extended system dynamics for solving charge equilibration models
    Journal of Chemical Theory and Computation, 2020
    Co-Authors: Songchen Tan, Itai Leven, Lin Lin, Teresa Headgordon
    Abstract:

    We present a new stochastic extended Lagrangian molecular dynamics solution to charge equilibration that eliminates self-consistent field (SCF) calculations, thus eliminating the computational bottleneck in solving the charge distribution with standard SCF solvers. By formulating both charges and chemical potential as latent variables and introducing a Holonomic Constraint that satisfies charge conservation, the SC-XLMD method accurately reproduces thermodynamic, dynamic, and structural properties within the framework of ReaxFF for a bulk water system and highly reactive RDX molecules simulated at high temperature. The SC-XLMD method shows excellent computational performance and is available in the publicly available LAMMPS package.

  • stochastic constrained extended system dynamics for solving charge equilibration models
    arXiv: Computational Physics, 2020
    Co-Authors: Songchen Tan, Itai Leven, Lin Lin, Teresa Headgordon
    Abstract:

    We present a new stochastic extended Lagrangian solution to charge equilibration that eliminates self-consistent field (SCF) calculations, eliminating the computational bottleneck in solving the many-body solution with standard SCF solvers. By formulating both charges and chemical potential as latent variables, and introducing a Holonomic Constraint that satisfies charge conservation, the SC-XLMD method accurately reproduces structural, thermodynamic, and dynamics properties using ReaxFF, and shows excellent weak- and strong-scaling performance in the LAMMPS molecular simulation package.

Kristi A Morgansen - One of the best experts on this subject based on the ideXlab platform.

  • including a non Holonomic Constraint in the fsp full space parameterization method for mobile manipulators motion planning
    International Conference on Robotics and Automation, 1997
    Co-Authors: Francois G Pin, C J Hacker, K B Gower, Kristi A Morgansen
    Abstract:

    The efficient utilization of the motion capabilities of mobile manipulators, i.e. manipulators mounted on mobile platforms, requires the resolution of the kinematically redundant system formed by the addition of the degrees of freedom (DOF) of the platform to those of the manipulator. At the velocity level, the linearized Jacobian equation for such a redundant system represents an underspecified system of algebraic equations, which can be subject to a set of Constraints such as obstacles in the workspace and various limits on the joint motions. A method, which we named the FSP, has been developed to resolve such underspecified systems with Constraints that may vary in time and in number during a single trajectory. The application of the method to motion planning problems with obstacle and joint limit avoidance was discussed in some of our previous work. In this paper, we present the treatment in the FSP of a non-Holonomic Constraint on the platform motion, and give corresponding analytical solutions for resolving the redundancy with a general optimization criterion. Comparative trajectories involving a 10 DOF mobile manipulator testbed moving with and without a non-Holonomic Constraint for the platform motion, are presented to illustrate the use and efficiency of the FSP approach in motion planning problems for highly kinematically redundant and constrained systems.

  • motion planning for mobile manipulators with a non Holonomic Constraint using the fsp full space parameterization method
    Journal of Robotic Systems, 1996
    Co-Authors: Francois G Pin, C J Hacker, Kristi A Morgansen, Faithlyn A Tulloch, K B Gower
    Abstract:

    The efficient utilization of the motion capabilities of mobile manipulators, i.e., manipulators mounted on mobile platforms, requires the resolution of the kinematically redundant system formed by the addition of the degrees of freedom (DOF) of the platform to those of the manipulator. At the velocity level, the linearized Jacobian equation for such a redundant system represents an underspecified system of algebraic equations, which can be subject to a varying set of contraints such as a non-Holonomic Constraint on the platform motion, obstacles in the workspace, and various limits on the joint motions. A method, which we named the Full Space Parameterization (FSP), has recently been developed to resolve such underspecified systems with Constraints that may vary in time and in number during a single trajectory. In this article, we first review the principles of the FSP and give analytical solutions for constrained motion cases with a general optimization criterion for resolving the redundancy. We then focus on the solutions to (1) the problem introduced by the combined use of prismatic and revolute joints (a common occurrence in practical mobile manipulators), which makes the dimensions of the joint displacement vector components non-homogeneous, and (2) the treatment of a non-Holonomic Constraint on the platform motion. Sample implementations on several large-payload mobile manipulators with up to 11 DOF are discussed. Comparative trajectories involving combined motions of the platform and manipulator for problems with obstacle and joint limit Constraints, and with non-Holonomic contraints on the platform motions, are presented to illustrate the use and efficiency of the FSP approach in complex motion planning problems. © 1996 John Wiley & Sons, Inc.

Francois G Pin - One of the best experts on this subject based on the ideXlab platform.

  • including a non Holonomic Constraint in the fsp full space parameterization method for mobile manipulators motion planning
    International Conference on Robotics and Automation, 1997
    Co-Authors: Francois G Pin, C J Hacker, K B Gower, Kristi A Morgansen
    Abstract:

    The efficient utilization of the motion capabilities of mobile manipulators, i.e. manipulators mounted on mobile platforms, requires the resolution of the kinematically redundant system formed by the addition of the degrees of freedom (DOF) of the platform to those of the manipulator. At the velocity level, the linearized Jacobian equation for such a redundant system represents an underspecified system of algebraic equations, which can be subject to a set of Constraints such as obstacles in the workspace and various limits on the joint motions. A method, which we named the FSP, has been developed to resolve such underspecified systems with Constraints that may vary in time and in number during a single trajectory. The application of the method to motion planning problems with obstacle and joint limit avoidance was discussed in some of our previous work. In this paper, we present the treatment in the FSP of a non-Holonomic Constraint on the platform motion, and give corresponding analytical solutions for resolving the redundancy with a general optimization criterion. Comparative trajectories involving a 10 DOF mobile manipulator testbed moving with and without a non-Holonomic Constraint for the platform motion, are presented to illustrate the use and efficiency of the FSP approach in motion planning problems for highly kinematically redundant and constrained systems.

  • motion planning for mobile manipulators with a non Holonomic Constraint using the fsp full space parameterization method
    Journal of Robotic Systems, 1996
    Co-Authors: Francois G Pin, C J Hacker, Kristi A Morgansen, Faithlyn A Tulloch, K B Gower
    Abstract:

    The efficient utilization of the motion capabilities of mobile manipulators, i.e., manipulators mounted on mobile platforms, requires the resolution of the kinematically redundant system formed by the addition of the degrees of freedom (DOF) of the platform to those of the manipulator. At the velocity level, the linearized Jacobian equation for such a redundant system represents an underspecified system of algebraic equations, which can be subject to a varying set of contraints such as a non-Holonomic Constraint on the platform motion, obstacles in the workspace, and various limits on the joint motions. A method, which we named the Full Space Parameterization (FSP), has recently been developed to resolve such underspecified systems with Constraints that may vary in time and in number during a single trajectory. In this article, we first review the principles of the FSP and give analytical solutions for constrained motion cases with a general optimization criterion for resolving the redundancy. We then focus on the solutions to (1) the problem introduced by the combined use of prismatic and revolute joints (a common occurrence in practical mobile manipulators), which makes the dimensions of the joint displacement vector components non-homogeneous, and (2) the treatment of a non-Holonomic Constraint on the platform motion. Sample implementations on several large-payload mobile manipulators with up to 11 DOF are discussed. Comparative trajectories involving combined motions of the platform and manipulator for problems with obstacle and joint limit Constraints, and with non-Holonomic contraints on the platform motions, are presented to illustrate the use and efficiency of the FSP approach in complex motion planning problems. © 1996 John Wiley & Sons, Inc.

K B Gower - One of the best experts on this subject based on the ideXlab platform.

  • including a non Holonomic Constraint in the fsp full space parameterization method for mobile manipulators motion planning
    International Conference on Robotics and Automation, 1997
    Co-Authors: Francois G Pin, C J Hacker, K B Gower, Kristi A Morgansen
    Abstract:

    The efficient utilization of the motion capabilities of mobile manipulators, i.e. manipulators mounted on mobile platforms, requires the resolution of the kinematically redundant system formed by the addition of the degrees of freedom (DOF) of the platform to those of the manipulator. At the velocity level, the linearized Jacobian equation for such a redundant system represents an underspecified system of algebraic equations, which can be subject to a set of Constraints such as obstacles in the workspace and various limits on the joint motions. A method, which we named the FSP, has been developed to resolve such underspecified systems with Constraints that may vary in time and in number during a single trajectory. The application of the method to motion planning problems with obstacle and joint limit avoidance was discussed in some of our previous work. In this paper, we present the treatment in the FSP of a non-Holonomic Constraint on the platform motion, and give corresponding analytical solutions for resolving the redundancy with a general optimization criterion. Comparative trajectories involving a 10 DOF mobile manipulator testbed moving with and without a non-Holonomic Constraint for the platform motion, are presented to illustrate the use and efficiency of the FSP approach in motion planning problems for highly kinematically redundant and constrained systems.

  • motion planning for mobile manipulators with a non Holonomic Constraint using the fsp full space parameterization method
    Journal of Robotic Systems, 1996
    Co-Authors: Francois G Pin, C J Hacker, Kristi A Morgansen, Faithlyn A Tulloch, K B Gower
    Abstract:

    The efficient utilization of the motion capabilities of mobile manipulators, i.e., manipulators mounted on mobile platforms, requires the resolution of the kinematically redundant system formed by the addition of the degrees of freedom (DOF) of the platform to those of the manipulator. At the velocity level, the linearized Jacobian equation for such a redundant system represents an underspecified system of algebraic equations, which can be subject to a varying set of contraints such as a non-Holonomic Constraint on the platform motion, obstacles in the workspace, and various limits on the joint motions. A method, which we named the Full Space Parameterization (FSP), has recently been developed to resolve such underspecified systems with Constraints that may vary in time and in number during a single trajectory. In this article, we first review the principles of the FSP and give analytical solutions for constrained motion cases with a general optimization criterion for resolving the redundancy. We then focus on the solutions to (1) the problem introduced by the combined use of prismatic and revolute joints (a common occurrence in practical mobile manipulators), which makes the dimensions of the joint displacement vector components non-homogeneous, and (2) the treatment of a non-Holonomic Constraint on the platform motion. Sample implementations on several large-payload mobile manipulators with up to 11 DOF are discussed. Comparative trajectories involving combined motions of the platform and manipulator for problems with obstacle and joint limit Constraints, and with non-Holonomic contraints on the platform motions, are presented to illustrate the use and efficiency of the FSP approach in complex motion planning problems. © 1996 John Wiley & Sons, Inc.

Songchen Tan - One of the best experts on this subject based on the ideXlab platform.

  • stochastic constrained extended system dynamics for solving charge equilibration models
    Journal of Chemical Theory and Computation, 2020
    Co-Authors: Songchen Tan, Itai Leven, Lin Lin, Teresa Headgordon
    Abstract:

    We present a new stochastic extended Lagrangian molecular dynamics solution to charge equilibration that eliminates self-consistent field (SCF) calculations, thus eliminating the computational bottleneck in solving the charge distribution with standard SCF solvers. By formulating both charges and chemical potential as latent variables and introducing a Holonomic Constraint that satisfies charge conservation, the SC-XLMD method accurately reproduces thermodynamic, dynamic, and structural properties within the framework of ReaxFF for a bulk water system and highly reactive RDX molecules simulated at high temperature. The SC-XLMD method shows excellent computational performance and is available in the publicly available LAMMPS package.

  • stochastic constrained extended system dynamics for solving charge equilibration models
    arXiv: Computational Physics, 2020
    Co-Authors: Songchen Tan, Itai Leven, Lin Lin, Teresa Headgordon
    Abstract:

    We present a new stochastic extended Lagrangian solution to charge equilibration that eliminates self-consistent field (SCF) calculations, eliminating the computational bottleneck in solving the many-body solution with standard SCF solvers. By formulating both charges and chemical potential as latent variables, and introducing a Holonomic Constraint that satisfies charge conservation, the SC-XLMD method accurately reproduces structural, thermodynamic, and dynamics properties using ReaxFF, and shows excellent weak- and strong-scaling performance in the LAMMPS molecular simulation package.