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Brake pulsation is a low frequency vibration phenomenon in brake judder. In this study, a simulation approach has been developed to understand the physics behind brake pulsation employing a full vehicle dynamics CAE model. The full vehicle dynamic model was further studied to understand the impact of suspension tuning variation to brake pulsation performance. Brake torque variation (BTV) due to brake thickness variation from uneven rotor wear was represented mathematically in a sinusoidal form. The wheel assembly vibration from the brake torque variation is transmitted to driver interface points such as the seat track and the steering wheel. The steering wheel lateral acceleration at the 12 o’clock position, driver seat acceleration, and spindle fore-aft acceleration were reviewed to explore the physics of brake pulsation. It was found that the phase angle between the left and right brake torque generated a huge variation in brake pulsation performance.

A driver model in multibody dynamic analysis software is to run a vehicle dynamics model in various customer applications: handling events such as lane changes and circle turns, and durability events such as Belgian blocks, hill courses, driveways, and race tracks. Ansys Motion is a robust multibody dynamic analysis software for many applications including vehicle dynamics simulations. This paper discusses Ansys Driver development in Ansys Motion. It addresses developments of critical driver features: identification of vehicle handling capability, a path planning from complex road profiles, an analog filter design, and a longitudinal and lateral control of vehicle models. It also discusses how to achieve the robustness of the driver model for various customer simulation scenarios not affecting simulation output due to too much driver control. This study presents a couple of examples of handling and durability event simulations.