Upgrading the ATB Model Code from FORTRAN 77 to FORTRAN 90

摘要

The Articulated Total Body (ATB) Model and its predecessors have been in use for over twenty-five years to study the effects of various force environments on the response of a multi-body subject. The ATB model has been used by both government and industry to study the effects of automobile crashes, aircraft ejections, and other accident scenarios. The applications of the ATB model have varied since its inception, and it is now commonly used for accident reconstruction, ergonomic simulations and a myriad of other situations where human body motion is modeled. The ATB Model was originally written in the FORTRAN IV (FORTRAN 66) programming language, but with time the code has gradually been modified to become essentially Fortran 77 compliant code. This modernization of the code has helped to reduce some of the clever coding logic originally employed to circumvent some of the hardware constraints of the earlier computers, such as purposely allowing arrays to overflow in adjacent memory locations to conserve memory space. With the increased use of the ATB model, it would be beneficial to have the program coded in a more modem modular format that is readily amenable to future enhancements. Such a modular version of the code would also easily interface with other programs, such FEM and aerodynamic codes, other dynamics codes, feedback control packages, graphics packages, and numerous other related codes. In addition, such a modular code would lend itself to faster debugging and reduce the potential for undetected errors. The Fortran 90 programming language was chosen as the upgrade path for the ATB Model code for a number of reasons. Since Fortran 90 is a superset of Fortran 77, any standard Fortran 77 code should run without modification.