A Generalized Framework for Interactive Dynamic Simulation for MultiRigid Bodies

Abstract

Abstract-This paper presents a generalized framework for dynamic simulation realized in a prototype simulator called the Interactive Generalized Motion Simulator (I-GMS), which can simulate motions of multirigid-body systems with contact interaction in virtual environments. I-GMS is designed to meet two important goals: generality and interactivity. By generality, we mean a dynamic simulator which can easily support various systems of rigid bodies, ranging from a single free-flying rigid object to complex linkages such as those needed for robotic systems or human body simulation. To provide this generality, we have developed I-GMS in an object-oriented framework. The user interactivity is supported through a haptic interface for articulated bodies, introducing interactive dynamic simulation schemes. This user-interaction is achieved by performing push and pull operations via the PHANToM haptic device, which runs as an integrated part of I-GMS. Also, a hybrid scheme was used for simulating internal contacts (between bodies in the multirigid-body system) in the presence of friction, which could avoid the nonexistent solution problem often faced when solving contact problems with Coulomb friction. In our hybrid scheme, two impulse-based methods are exploited so that different methods are applied adaptively, depending on whether the current contact situation is characterized as "bouncing" or "steady." We demonstrate the user-interaction capability of I-GMS through on-line editing of trajectories of a 6-degree of freedom (dof) articulated structure.

Haptic Manipulation of Serial-Chain Virtual Mechanisms

“…In all experiments, users operate the three-link planar VM (dimensions and inertial properties are given in Table I) 7 . Trajectories are represented in task space coordinates, with Ü and Ý being coordinates in the plane of motion 7 These values represent the maximum impedance of the virtual coupler for which the interaction is stable, i.e., for which chattering does not occur.…”

An iterative predictor–corrector approach for modeling static and kinetic friction in interactive simulations

“…The MLCP formulation involves a system of linear inequalities accompanied by orthogonality conditions. This approach is commonly employed in modeling friction for rigid body simulations [8,9]. In recent years finite element (FE) based methods that are common in engineering, are gaining wide-spread use in graphics applications.…”

Interactive Dynamic Simulator for Multibody Systems

“…13 speci¯cally designed for grasping, the framework of Son et al 14 which includes interactivity but does not explain how contact with friction is handled, or those of Hale et al 15 and Nagasaka et al 16 Most of the simulators we can¯nd in the literature are however not designed for general prototyping purposes nor to simulate complex systems such as humanoid robots, including accurate and fast contact models while sensing force feedback. Moreover they are not freely available to the research community.…”