INTRODUCTION TO ERGONOMICS IN DIGITAL ENVIRONMENTS

INTRODUCTION

The design of workplaces and products continues to migrate from paper to the computer, where analysis accuracy, visualization, and collaboration utilities allow designs to be realized much faster and better than ever before. As the pace of this development accelerates with the increased capabilities of the software design tools, less time is spent on physical prototyping, allowing for shortened time- to-market for new products. Ergonomists, who in the past used the physical prototypes to perform human factors analyses, are now challenged to move the analysis into the virtual domain using new tools and methods. Usability, maintainability, physical ergonomic assessments, psychological percep- tion, and procedural training are some of the human factors issues that might benefit from analysis prior to the first physical incarnation of the design. While this represents a challenge for the ergo- nomists, it provides an opportunity to effect change in the designs much earlier than was typically possible in the past and to take advantage of the dramatically reduced cost of design alterations in the early design phases. Commercial pressures that leverage the cost benefits offered by complete ‘‘in-tube’’ design are driving a rapid development of the available computer technologies. Human simulation technology is no exception. Contemporary human modeling software is assimilating a variety of human modeling knowledge, including population anthropometry descriptions and physical capability models. Companies are deploying these human modeling products to allow their ergonom- ists and designers to populate digital representations of products and workplaces efficiently with virtual human figures and ask meaningful questions regarding the likely performance of actual people in those environments. Identification of ergonomic design problems early in the design phase allows time-consuming and expensive reworking of the manufacturing process or design to be avoided.

Computerized human modeling itself has been evolving over some time. Perhaps the first attempt to develop a computer-integrated tool for performing reach tasks was performed by Vetter and Ryan for the Boeing Aircraft company in the late 1960s. This effort was referred to as the ‘‘First Man’’ program, which later became ‘‘Boeman.’’ This software was later expanded by the USAF Aerospace Medical Research Laboratory Crew Systems’ Interface Division, which added the ability to simulate a variety of male and female anthropometric dimensions while seated in different types of aircraft, culminating in the software COMBIMAN. In the 1980s, this software was further developed at AMRL to address maintenance tasks, adding performance models of lifting, pulling, and pushing on various tools and objects placed in the hands, and became CrewChief. During this same time in Europe, a wide variety of models were developed, perhaps the most widely known being SAMMIE (System for Aiding Man–Machine Interaction Evaluation), developed by Case, Porter, and Bonney at Not- tingham and Loughborough Universities in the United Kingdom. SAMMIE was conceived as a very general model for assessing reach, interference, and sight-line issues within a CAD environment. The details of these developments are described in greater depth elsewhere (e.g., Chaffin 2000; Bubb 1999; Badler 1993). Perhaps as a testament to the rapid development in this field, new human models that are integrated in modern CAD, 3D visualization, and automation simulation products are now the most popular and seeing the most rapid development and deployment. These include Deneb Ergo, EAI Jack, Genicom Safeworks, TecMath Ramsis, and Tecnomatix RobCAD Man.

This chapter reviews the foundation of contemporary human modeling technology for physical ergonomics and presents examples of how digital humans are currently used in industry. The chapter concludes with a discussion of the current development efforts in the area of human modeling.