GK-DEVS: Geometric and kinematic DEVS formalism for simulation modeling of 3-dimensional multi-component systems

Abstract

A combined discrete/continuous simulation methodology based on the DEVS (discrete event system specification) formalism is presented in this paper that satisfies the simulation requirements of 3-dimensional and dynamic systems with multi-components. We propose a geometric and kinematic DEVS (GK-DEVS) formalism that is able to describe the geometric and kinematic structure of a system and its continuous state dynamics as well as the interaction among the multi-components. To establish one model having dynamic behavior and a particular hierarchical structure, the atomic and the coupled model of the conventional DEVS are merged into one model in the proposed formalism. For simulation of the continuous motion of 3-D components, the sequential state set is partitioned into the discrete and the continuous state set and the rate of change function over the continuous state set is employed. Although modified from the conventional DEVS formalism, the GK-DEVS formalism preserves a hierarchical, modular modeling fashion and a coupling scheme. Furthermore, for the GK-DEVS model simulation, we propose an abstract simulation algorithm, called a GK-Simulator in which data and control are separated and events are scheduled not globally but hierarchically so that an object-oriented principle is satisfied. The proposed GK-DEVS formalism and the GK-Simulator algorithm have been applied to the simulation of a flexible manufacturing system consisting of a 2-axis lathe, a 3-axis milling machine, and a vehicle-mounted robot.