5. Modeling and Operator Simulations for Early Development of Army Unmanned Vehicles: Methods and Results

The most important advance in system design is the development of modeling and simulation methods to predict complex performance before prototypes are developed. New systems are developed in a spiraling approach; as more is learned about the system, design changes are proposed and evaluated. This approach allows the engineering team to “spin out” early versions of the system for preliminary evaluation, permitting changes to be made to the system design without incurring unacceptable cost. Because of the complexity of human performance, current modeling techniques provide only a first approximation. However, it has been demonstrated that even simple, inexpensive modeling approaches are useful in uncovering workload and performance problems related to developing systems (Barnes & Beevis, 2003). More important, these models can serve as the basis for operator simulation experiments that verify and also calibrate the original models. Furthermore, early field tests and system of systems demonstrations that can validate these results under actual conditions are becoming an increasingly significant part of the early design process. Fig. 1 illustrates this interdependence indicating a spiraling process throughout the design starting with simple predictive methods and progressing to more expensive validation methods. These iterations should continue until most of the soldier's variance is accounted for, and before any formal soldier testing is conducted. Fig. 1 presents the ideal combination of techniques; not all systems can be evaluated this thoroughly but more cost-effective modeling and simulation tools combined with realistic field exercises should make this approach more the norm as future unmanned systems are developed (Barnes & Beevis, 2003). In the remainder of this chapter, several case studies are presented to illustrate how the techniques in Fig. 1 have been applied in UAV programs.