Improving the braking efficiency of two-axle vehicles when performing emergency braking under operating conditions

Abstract

To substantiate the possibility of increasing the braking efficiency of two-axle vehicles during the operational period, the method of mathematical modeling of the movement of a two-axle motor vehicle, braked on roads with a transverse slope, taking into account the action of the components of the aerodynamic drag force, was used. It has been established that in the case of performing emergency braking with a two-axle vehicle, there is a potential for the implementation of a larger braking force on the rear axle at the initial moment of braking, which, as a result, will make it possible to realize a relatively greater efficiency.In addition, due to the projected growth in the intensity and speed of vehicles, as well as the throughput of highways, increased requirements are imposed on ensuring road safety. An increase in the intensity and speed of movement, in particular, of two-axle vehicles, both equipped and not equipped with electronic braking tracking systems, can be achieved through a number of measures, including ensuring the minimum allowable distance between individual vehicles moving in a single stream.

Theoretical studies were carried out on a mathematical model of a two-axle vehicle being braked at various initial speeds of movement, varying within the range of 60–100 km / h. It was found that, depending on the value of the initial braking speed, the change in the normal load on the rear axle wheels can reach 23–32% at the initial moment of emergency braking on dry asphalt concrete.

Analysis of the relative change in the normal loads on the axles of vehicles during emergency braking, taking into account operational factors, shows that the normal loads on the rear axle, obtained from the refined dependencies, differ from the normal loads on the same axle, determined by the classical method, which creates the preconditions for reinforcing the rear brakes of a vehicle in order to increase its braking efficiency. However, this should involve electronic devices that monitor the change in the normal load on the wheels of the vehicle.