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A new, systematic approach to the design-evaluation-test product development cycle is described wherein the vehicle design and simulation environments are integrated. This methodology is applied to brake mechanical design and material selection. Time-domain computations within a vehicle dynamic simulation environment account for brake and lining geometry and material properties, actuator properties, and temperature effects. Two examples illustrate the utility of this approach by examining: the effect of varying hydraulic cylinder diameter on passing federally mandated stopping distance tests, and the effect of S-cam actuator adjustment on the performance of air brakes on a tractor-trailer. The simulation results are compared with experimental vehicle stopping distance tests to assess the validity of the simulations.

The EDSMAC simulation model has been in widespread use by vehicle safety researchers since its introduction in 1985. Several papers have been published that describe the model and provide validations of its use. In 1997, the collision and vehicle dynamics models were extended significantly. The main control logic was also extended and generalized. The resulting model was named EDSMAC4. This paper describes the EDSMAC4 model with particular attention to the extensions to the original algorithms. The paper also provides a validation of the new model by direct comparison to staged collision experiments and the results from the previous EDSMAC model.