Robert E. Young

Physical simulation: The use of scaled-down fully functional components to analyze and design automated production systems

Abstract This paper presents and discusses the physical simulation methodology currently employed in the Industrial Automation Laboratory in the Department of Industrial Engineering at Texas AM constructing scaled-down, functionally-equivalent generic models of the components with mechanical breadboarding kits; and then using these generic models to construct fully functional scaled-down systems. Thus, it allows us to evaluate the dynamic physical interactions using the models to confirm design decisions and to develop and test system software in parallel with the construction of the full-sized system. This approach should allow a cost reduction in the design cycle for complex automation because (1) through it we can identify design errors early, and (2) it provides a mechanism for the parallel development of both the computer hardware/software control system and the systems machinery. The methodology is currently under development in the Industrial Automation Laboratory in the Department of Industrial Engineering at Texas A&M University.

Confidence inteefals foe teamsitiom probabilities in too-state markov chains

This paper develops approximations for the distributions of the maximum likelihood estimators of the transition probabilities in a finite state, irreducible, aperiodic Markov chain* These distributions are then used to compute confidence intervals for the transition probabilities, and to make sample size projections. The techniques used are presented by first considering the two-state Markov chain, and then the many state Markov chain is discussed.

The Kaspar wire-forming machine: an application of physical simulation to the disign and implementation of an automated process control system

Abstract This paper presents and discusses a direct application of physical simulation modeling to a joint development effort between Kaspar Wire Works, Inc. and the Industrial Automation Laboratory in the Industrial Engineering Department at Texas A&M University. Physical simulation is the study of complex automated manufacturing and material handling systems through the use of mini- and microcomputers using full-sized software. By modeling the mechanical portions of the wire forming machine designed by Kaspar, the Industrial Automation Laboratory was able to develop the process control system as a parallel effort, thus saving time and expense. Paralleling the mechanical and control development resulting in early identification and prompt resolution of problem areas and design deficiencies. User-friendliness of the operator/system software interface was greatly enhanced due to an extended test and evaluation period provided by the operational model. This paper encompasses a brief explanation of physical simulation, addresses the development of the process control system and physical model in detail, and summarizes the benefits of this technology to the implementation of automated industrial control systems.

GASPL/I: A PL/I based simulation language

GASPL/I is a PL/I based simulation language structured around the GASP simulation philosophy. It is a discrete-event simulator which extends and refines the principles employed in the FORTRAN based GASP II language. In this paper, an example of the use of GASPL/I is presented. The example involves the simulation of a project when resources are limited. Emphasis is given to the file system and the multiple-entry feature of GASPL/I. A portion of the GASPL/I coding for the example is included.