Sizing of anti-lock braking system for Formula SAE vehicles

The anti-lock braking system (ABS) has the purpose of controlling the wheel slip, in order to maintain steering and stability during braking. Due to the increasing search for safety and performance in competition vehicles, it is sought to minimize braking distances for the purpose of reduce track time. It is known that a slip control task is not trivial, where one of the main reasons is the high amount of uncertainties involved. Thus, the present paper aims to simulate a SAE vehicle with and without ABS using reliable experimental data of friction interfaces. The performance of the system is evaluated by a longitudinal vehicle model, supported by principles of vehicular dynamics, dynamometric test and track data. The model has a feedback control system with two proportional, integral, derivative (PID) loops. A sensor monitors wheel slip and feed it to the controller. This, actuates the hydraulic modulator operated by the opening or closing of the valves, with the objective of maintain the desired output of the system. Simulation results are used to estimate contributions in straight braking time during typical events of Autocross and Endurance of FSAE. Thus, a quantitative analysis about overall placement contribution of the device implementation is presented.