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This paper presents the development of a hardware in the loop (HIL) simulation system for evaluating and optimizing the interactions of the brake system with the vehicle. This unique HIL set-up consists of an inertial brake dynamometer with a brake corner module, an electronic control unit, a real time 3D total vehicle model and a computer system with a high-speed operating platform. The HIL system simultaneously confers advantages of both computer modeling and hardware testing. It offers the capability to do upfront design and assess performance of the foundation brake hardware and the chassis controls, as well as their interactions, in advance of testing and tuning a vehicle. This powerful tool enables reduction in development time and cost. A simple example of applying the brake dynamometer HIL system will be presented.

Friction behavior is one of the most critical factors in brake system design and performance. For up-front design and system modeling it is desirable to be able to describe a lining's frictional behavior as a function of the local conditions, such as contact pressure, temperature and sliding speed. Typically, frictional performance is assessed using brake dynamometer testing of full-scale hardware, and an average friction value is used during brake system development. This traditional approach yields an average brake friction coefficient that is hardware-dependent and fails to capture in-stop friction variation; it is also unavailable in advance of component testing, ruling out true up-front design and prediction. To address these shortcomings, a scaled inertial brake dynamometer was used to determine the frictional characteristics of candidate lining materials.