Influences of Initial Braking Velocity and Passenger Capacity on Mean Fully Developed Deceleration

In order to improve the comprehensive and rationality of examination for driving braking performance with Mean Fully Developed Deceleration (MFDD) in road test, also to provide a basis for driving braking performance evaluation with MFDD when real driving, an approach for determining the MFDD threshold is proposed considering initial braking velocity and passenger capacity. According to the vehicle braking performance road test rules in GB7258, a simulation model is built, and simulation tests are made with different initial braking velocities. Based on simulation data, MFDD is calculated, and the curve of MFDD with initial braking velocity is also given, and then the effects of initial braking velocity on MFDD and its threshold are analyzed; the curves of MFDD thresholds with initial braking velocity are plotted with no-load and full-load respectively. The influence of passenger capacity on MFDD threshold is analyzed, and the curve of MFDD threshold with passenger capacity is given, too. Finally, the formula of MFDD threshold with initial braking velocity, seating capacity and passenger capacity is resulted.