Emergency Braking System: Verification of system behavior on commercial vehicles equipped with drum braking system

Abstract

In recent years, new technologies are being developed and applied to commercial vehicles. Such technologies support on development and implementation of new functions making these products safer, benefiting the society in general. One of the areas that can be mentioned is the vehicle safety. Among too many technologies, the emergency brake system is that one who came to support and assist drivers in critical situations that cannot be avoided. The Advanced Emergency Brake System, AEBS, consists of identifying other vehicles ahead, and, in case of detecting a risk of collision, automatically applies the service brakes to avoid accidents. The system works in situations when there is a sudden traffic stop, the vehicle is passing through intersections and when the driver distracts due to inappropriate use of mobile telephone devices. The aim of this work was to evaluate the emergency braking performance of a 6x4 tractor with a double semi-trailer, at flat asphalt. Both vehicles of combination were equipped with drum brakes. To monitor the braking performance, the vehicle speed, the brake temperature, and braking pressure were collected using, respectively, a global positioning system, GPS, thermocouples and pressure transducers. The dynamic tests were performed according to the ECE R131 European resolution, using a balloon car as target. An additional driving condition was simulated during the tests: elevated temperature level of the brakes. The tests led to the conclusion that the efficiency during emergency braking, under normal and critical conditions, fulfilled the requirements without any stability and drivability degradation. Regardless of the temperature, the system remained operating within the established technical limits. It was therefore concluded that the emergency braking system, on vehicle combination using drum brakes, met the requirements established by resolution ECE R131 in a fully satisfactory manner.