Modeling and Simulation of Assembly in a Free-floating Work Environment by a Free-floating Robot

1996 ◽  
Vol 118 (1) ◽  
pp. 115-120 ◽  
Author(s):  
S. K. Agrawal ◽  
M. Y. Chen ◽  
M. Annapragada
Keyword(s):  
Angular Momentum ◽  
Work Environment ◽  
Multibody Systems ◽  
Rigid Body Dynamics ◽  
Analytical Models ◽  
Impact Dynamics ◽  
Dynamics Of Multibody Systems ◽  
Body Dynamics ◽  
Freely Moving ◽  
Self Motion

Freely moving systems in space conserve linear and angular momentum. As moving systems collide, the velocities get altered due to transfer of momentum. The development of strategies for assembly in a free-floating work environment requires a good understanding of primitives such as self motion of the robot, propulsion of the robot due to onboard thrusters, docking of the robot, retrieval of an object from a collection of objects, and release of an object in an object pool. The analytics of such assemblies involves not only kinematics and rigid body dynamics but also collision and impact dynamics of multibody systems. This paper presents analytical models of assembly, built from the models of primitives, and some possible strategies for overall assembly.

Dynamics of Flexible Beams and Plates in Large Overall Motions

1992 ◽  
Vol 59 (4) ◽  
pp. 991-999 ◽  
Author(s):  
Z. E. Boutaghou ◽  
Arthur G. Erdman ◽  
Henryk K. Stolarski
Keyword(s):  
Dynamic Response ◽  
Nonlinear Interaction ◽  
Multibody Systems ◽  
Present Theory ◽  
Rigid Body Dynamics ◽  
Flexible Beams ◽  
Constrained Multibody Systems ◽  
Dynamic Stiffening ◽  
Body Dynamics ◽  
Arbitrary Representation

The dynamic response of flexible beams, plates, and solids undergoing arbitrary spatial motions are systematically derived via a proposed approach. This formulation is capable of incorporating arbitrary representation of the kinematics of deformation, phenomenon of dynamic stiffening, and complete nonlinear interaction between elastic and rigid-body dynamics encountered in constrained multibody systems. It is shown that the present theory captures the phenomenon of dynamic stiffening due to the transfer of the axial and membrane forces to the bending equations of beams and plates, respectively. Examples are presented to illustrate the proposed formulations.

scholarly journals On the relations between kinetic energy and linear momentum, angular momentum of the particle and of the rigid body

2001 ◽  
Vol 23 (2) ◽  
pp. 110-115
Author(s):  
Nguyen Van Khang
Keyword(s):  
Angular Momentum ◽  
Kinetic Energy ◽  
Rigid Body ◽  
Partial Derivative ◽  
Multibody Systems ◽  
Linear Momentum ◽  
Dynamics Of Multibody Systems

Using the definition for the partial derivative of a scalar in respect to the vector, this paper presents the relations between kinetic energy and linear momentum, angular momentum of the particle and of the rigid body. The obtained results are useful for the investigation of the dynamics of multibody systems

Bond Graphs for Flexible Multibody Systems

1979 ◽  
Vol 101 (1) ◽  
pp. 50-57 ◽  
Author(s):  
D. L. Margolis ◽  
D. C. Karnopp
Keyword(s):  
Rigid Body ◽  
Multibody Systems ◽  
Rigid Body Dynamics ◽  
Bond Graphs ◽  
Flexible Bodies ◽  
Actuator Dynamics ◽  
Bending Mode ◽  
Body Dynamics ◽  
Rigid Body Modes ◽  
Bending Modes

A method is presented for the analysis and simulation of the dynamic response of systems containing several long, flexible bodies driven by actuators at joints and attachment points. Applications include remote manipulators, cranes, and complex spacecraft. The geometric nonlinearities of rigid body dynamics are retained as well as small bending mode vibrations based upon linearized analysis. Since bond graphs are used, the actuator dynamics are readily incorporated. The results of simulation of a two body system with electrical actuators and up to three bending modes per body in addition to the rigid body modes are shown.

On the Geometric Stiffness Matrices in Flexible Multibody Dynamics

1995 ◽  
Vol 117 (4) ◽  
pp. 452-461 ◽  
Author(s):  
S. S. K. Tadikonda ◽  
H. T. Chang
Keyword(s):  
Multibody Systems ◽  
Flexible Multibody Dynamics ◽  
Flexible Body ◽  
Joint Simulation ◽  
Geometric Stiffness ◽  
Stiffness Matrices ◽  
Body Dynamics ◽  
Geometric Stiffening ◽  
Flexible Body Dynamics ◽  
Self Motion

A flexible branch body in a multibody chain undergoing large overall motions experiences geometric stiffening effects due to its own motions and interbody forces arising from bodies outboard of it. The self-motion effects are modelled through the use of 21 geometric stiffness matrices, in the literature, for an arbitrarily shaped flexible body. In this paper, the effect of interbody forces on the flexible body dynamics is modelled using up to 6 additional geometric stiffness matrices per outboard joint. Simulation results presented indicate that for a flexible body consisting of outboard bodies one may consider only the interbody force effects, without loss of accuracy, and thus significantly reduce the computational burden. This approach is especially suitable for multibody systems such as the Shuttle Remote Manipulator System, where the long boom masses are of similar magnitude, or when the payloads are several orders of magnitude larger than the link masses.

scholarly journals Slipping–rolling transitions of a body with two contact points

2021 ◽  
Author(s):  
Mate Antali ◽  
Gabor Stepan
Keyword(s):  
Rigid Body ◽  
Contact Point ◽  
Static Friction ◽  
Rigid Body Dynamics ◽  
Contact Forces ◽  
Friction Forces ◽  
Contact Points ◽  
Body Dynamics ◽  
Coulomb Model ◽  
Rigid Surfaces

AbstractIn this paper, the general kinematics and dynamics of a rigid body is analysed, which is in contact with two rigid surfaces in the presence of dry friction. Due to the rolling or slipping state at each contact point, four kinematic scenarios occur. In the two-point rolling case, the contact forces are undetermined; consequently, the condition of the static friction forces cannot be checked from the Coulomb model to decide whether two-point rolling is possible. However, this issue can be resolved within the scope of rigid body dynamics by analysing the nonsmooth vector field of the system at the possible transitions between slipping and rolling. Based on the concept of limit directions of codimension-2 discontinuities, a method is presented to determine the conditions when the two-point rolling is realizable without slipping.

Time-Accurate Simulation of Longitudinal Flight Mechanics with Control by CFD/RBD Coupling

2012 ◽  
Vol 226-228 ◽  
pp. 788-792 ◽  
Author(s):  
Dong Guo ◽  
Min Xu ◽  
Shi Lu Chen
Keyword(s):  
Computational Study ◽  
Rigid Motion ◽  
Rigid Body Dynamics ◽  
Flight Mechanics ◽  
Control Surface ◽  
Free Flight ◽  
Body Dynamics ◽  
Computational Fluid Dynamics Cfd ◽  
Coupled Solution ◽  
Surface Deflections

This paper describes a multidisciplinary computational study undertaken to compute the flight trajectories and simultaneously predict the unsteady free flight aerodynamics of aircraft in time domain using an advanced coupled computational fluid dynamics (CFD)/rigid body dynamics (RBD) technique. This incorporation of the flight mechanics equations and controller into the CFD solver loop and the treatment of the mesh, which must move with both the control surface deflections and the rigid motion of the aircraft, are illustrated. This work is a contribution to a wider effort towards the simulation of aeroelastic and flight stability in regions where nonlinear aerodynamics, and hence potentially CFD, can play a key role. Results demonstrating the coupled solution are presented.

scholarly journals Dynamics of Multibody Systems With Spherical Clearance Joints

2005 ◽  
Author(s):  
P. Flores ◽  
J. Ambro´sio ◽  
J. C. P. Claro ◽  
H. M. Lankarani
Keyword(s):  
Contact Force ◽  
Multibody Systems ◽  
Contact Forces ◽  
Force Model ◽  
Clearance Joints ◽  
Continuous Contact ◽  
Clearance Joint ◽  
Contact Force Model ◽  
Dynamics Of Multibody Systems ◽  
The Impact

This work deals with a methodology to assess the influence of the spherical clearance joints in spatial multibody systems. The methodology is based on the Cartesian coordinates, being the dynamics of the joint elements modeled as impacting bodies and controlled by contact forces. The impacts and contacts are described by a continuous contact force model that accounts for geometric and mechanical characteristics of the contacting surfaces. The contact force is evaluated as function of the elastic pseudo-penetration between the impacting bodies, coupled with a nonlinear viscous-elastic factor representing the energy dissipation during the impact process. A spatial four bar mechanism is used as an illustrative example and some numerical results are presented, being the efficiency of the developed methodology discussed in the process of their presentation. The results obtained show that the inclusion of clearance joints in the modelization of spatial multibody systems significantly influences the prediction of components’ position and drastically increases the peaks in acceleration and reaction moments at the joints. Moreover, the system’s response clearly tends to be nonperiodic when a clearance joint is included in the simulation.

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