A zero-emission braking system: experimental setup, system characterization and model validation

Following the current need of the automotive sector on reducing secondary emissions coming from non-exhaust sources, this paper presents an innovative zero-emissions magneto-rheological braking system, specifically designed to meet future brake emission targets while maintaining state-of-the-art brake performance. In particular the article focusses on the experimental setup definition to evaluate the full-sized prototype under real load conditions and presents the preliminary results obtained from the experimental campaign. The zero-emission braking prototype has been developed for reaching performance compatible with the automotive application, specifically a segment-A vehicle, being able to generate enough braking torque as to perform an emergency brake maneuver without any other traditional braking system. A central aspect to confirm system’s performance is the development of a test bench engineered for assessing the magneto-rheological braking technology. Detailed insights into the comprehensive strategy underpinning the design of the test bench are provided, emphasizing its ability to faithfully replicate diverse driving scenarios and evaluate multiple braking performances. Following initial virtual validation, the first brake prototype, featuring an electric in-wheel motor with an integrated innovative braking system, was experimentally tested on a dedicated bench to verify peak torque performance and system reliability. The paper thus presents the braking results obtained by the first tests, considering the maximum braking capability of the system, its behavior under multiple rolling conditions and under different braking commands applied, to develop a braking solution able to maintain similar braking performance as traditional disk-brakes, but, at the same time, respecting the stringent environmental braking regulations. By adhering to stringent testing and validation, the study advances automotive braking technologies, promoting sustainable and efficient solutions aligned with environmental goals.