Problems in the implementation of the control system for vertical reactions of vehicle wheels

Abstract

One of the new active safety systems of the automobile is a system for stabilizing the vertical reactions of the wheels when moving along a periodic profile. The effectiveness of this system largely depends on the success of measuring the values of the vertical reactions of the wheels of the vehicle in motion. The possibility of solving this problem is considered in the article. As a first method for determining the radial reaction in a tire, the method for estimating the radial force from the change in internal pressure in it is considered. Theoretical analysis of this problem based on solving the simplest models, as well as more advanced models using the finite element method, is presented in the article. Another method for determining the radial force in the tire is to measure the radial deformation of the tire in the area of the contact spot. Two methods for determining radial deformation of a tire are considered in the article. One way is to use laser technology. The laser sensor is fixed to the rim of the vehicle wheel, which ensures a constant measurement of radial deformation at one point of the rotating tire. The use of such a device in the system of stabilizing the vertical reactions of the wheels of the automobile is almost impossible, because the frequency of the desired signal is too small. A more advanced version of the measuring device with a gyroscope ensures the continuity of the direction of the laser beam at one point - the center of the contact spot. This ensures the continuity of measuring the radial deformation of the tire during the movement. Another way is to use an annular chamber with a fluid supported on a ring like a ring fixed on the rim of a so-called “safe” wheel. Increasing the pressure in the chamber during radial deformation of the tire makes it possible to evaluate it. Another method of continuous measurement of radial force on the wheel is associated with performing measurements of the vertical acceleration of the center of the wheel and the total force transferred by the suspension to the wheel of the vehicle.