At elevated temperatures, such as those encountered under race track or fade test conditions, the closed-form solution to the lumped capacitance model for characterizing brake cooling (fitted to a standard cooling test temperature range) tends to break down and provide an inaccurate representation of brake rotor cooling behavior. Accurate prediction of cooling is fundamental to brake system component sizing and selection of materials at the early stages of a vehicle program; this is especially true of a high performance vehicle with track performance requirements. To this end, alternative approaches to characterizing brake cooling have been examined to determine their suitability for use in measurement and simulation of brake performance.In this paper, three methods of representing in-vehicle measured brake cooling behavior are reviewed and explained (standard temperature range closed-form solution lumped capacitance model, high temperature range closed form solution lumped capacitance model, and numerically solved linearly varying specific heat capacity lumped capacitance model). The efficacy of each model when employed in brake system thermal models is examined via case studies, in which modeled rotor temperatures are compared to in-vehicle measured high energy fade test results. The influence of radial temperature gradients developed in the rotor on cooling behavior representation and on model to vehicle test correlation is also considered.

This paper presents a generic range sensing model and method for object detection in 3D space. Due to the complexity and stochastic nature of the physics involved, modeling the physics of sensor and sensing is often very difficult, if not impossible, in particular under unstructured environments. This paper presents a geometric approach that provides an abstraction on the functions of range sensing and objects detection. This is to enable modeling and simulation of vehicle interactions among one another under traffic and with surrounding environment for research and development, early testing and verification of many active safety, driver-assistance and sensor-guided autonomous driving features and functions.

This paper describes an integrated environment for building quick software prototype for chassis/driveline controls and integration. Under this environment, engineers are able to focus on chassis/driveline controls and integration algorithm development quickly and effectively through user-friendly modelling and simulation interfaces. The system architecture for providing the flexibility in control algorithm development is discussed. The environment under which chassis/driveline dynamics controls are seamlessly integrated is described and the features of control algorithm library sharing and reusability are briefly discussed.

This paper provides an overview of VehSim, a PC Windows-based vehicle simulation software for vehicle dynamics, controls and integration. The function and features of VehSim are discussed in general. With its high fidelity, flexibility, portability and user-friendly interfaces, VehSim provides an integrated development environment for engineers to conduct vehicle, especially chassis/driveline modeling, simulation and control algorithm design and to build quick software prototypes to accelerate chassis/driveline controls and integration development. VehSim’s structure, which includes file system, database structure and user graphic interfaces are described. Through its modularized and hierarchical structure, VehSim features great flexibility for engineers to customize their own project needs by developing their own control algorithms or incorporating supplier provided subsystem models and control modules into vehicle dynamics. With the compatibility of VehSim to real-time environment, engineers are able to perform both quick off-line simulation and on-line in-vehicle validation for algorithm development. VehSim also provides built-in user-friendly model preprocessors and postprocessors for engineers to easily build vehicle and/or subsystem models, adjust numerical computation parameters and process the simulation results on line. A 3D solid model based motion animator is also integrated in VehSim for on-line visual processing of simulation results.