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The design of vehicles increasingly challenges existing cost, weight, durability, and handling regimes. This challenge is further compounded by pressure to decrease or limit the duration of the design cycle. The simulation of vehicle dynamic behavior commonly applies just rigid, or better rigid and linear flexibility models to predict motions and determine load cases. However, as the boundaries of materials are pushed these are becoming insufficient to accurately predict behavior. Alternatively, complete nonlinear finite element representations of vehicle dynamics are always possible but are presently infeasible for the support of a single design under virtual test, not to mention several design iterations. To address these issues, a novel abstract multi-rate simulation method is outlined which is designed to exploit the richness of available model in the vehicle dynamics domain.

The service life of a military ground vehicle is measured in decades and throughout its life it is expected to see several theaters with severe terrain and complex evolving operating conditions. The core of the vehicle, like the chassis and the hull, are often in continuous use, undergoing routine repair, reset, and re-fielding. Other components attached to the hull and chassis have more limited life spans and by design become damaged, worn-out, or outdated and are repaired, replaced, and/or upgraded. New components like armor, weapons, and sensor packages are frequently added to the existing structure for improved mission performance (survivability, lethality, etc.) as threats and strategies change. Designing military vehicles for durability is therefore very challenging and should not end when the product is designed, validated with hardware tests, manufactured, and sold.

A simple and robust path follower has been developed for use in road loads simulations as required for virtual evaluation of vehicle durability and strength. The path follower is described as simple because it has a single tunable parameter and minimal control logic. It is deemed robust because the same gain setting can be used over a wide range of terrains, paths, and speeds. Path following performance is successfully demonstrated with a multibody vehicle model of a generic heavy truck for a variety of terrains, paths, and speeds. The convergence to the desired path during parameter tuning is observed to be monotonic. A physical interpretation of the gain as a maximum centripetal acceleration further enables vehicles in the same or similar classes of mobility characteristics (all off-road trucks for example) to utilize the same gain value.