No abstract

The main purpose of the work is to confirm influence of operating conditions at low temperatures on change in braking characteristics of cars. The factors influencing the result of braking are determined, cars from the general set of all vehicles operated in Ulan-Ude are selected, taking into account certain conditions. A test method is proposed that makes it possible to obtain functional dependences of the specific braking force on ambient temperature during storage of the vehicle, and also the functional dependences of the specific braking force on storage temperature under operating conditions in Ulan-Ude are obtained. The insignificant influence of air humidity on results of the braking process in conditions of Ulan-Ude was revealed. The correlation of the value of specific braking force from the ambient temperature was estimated, the statistical indices obtained indicate a high correlation between the compared values. The tasks of further studies that need to be performed to determine most complete picture of the influence of ambient temperature and air humidity on parameters of the functioning of brake system a vehicle were determined.

The article presents the results of the study aimed at improving the safety of motor vehicles (hereinafter - vehicle) under operating conditions. The estimation of indicators of vehicle stability is made by controlling the parameters characterizing change of the trajectory of the vehicle under the action of a lateral force when crossing a single irregularity. The results of the study are presented in the form of graphs and functional dependences. Using the revealed functional dependences reflecting the effects of the technical condition of the vehicle shock absorbers with the parameters, characterizing the change in its movement trajectory under the action of a lateral force, when crossing a single irregularity, a method for controlling the vehicle road holding of M1category was devised.

The article describes the mathematical apparatus classifying the movement of the sprung and unsprung vehicle masses in space, as well as the processes of interaction of its elastic tires with the road support surface when driving under the influence of lateral force. The results of calculations of the mathematical model allow one to scientifically justify the test modes and diagnostic parameters of the over-the-road method of monitoring the technical condition of shock absorbers. The normalized values of the found diagnostic parameters are proposed as criteria for assessing the vehicle stability when moving under the influence of lateral force and varying the technical condition of the shock absorbers.

Suspension faults can reduce wheel traction and therefore reduce vehicle stability. Existing diagnostic methods for the suspension do not take into account the stability of the vehicle. To control stability, it is proposed to use road and bench methods, characterized by suspension vibrations and constant lateral force. Theoretical studies were carried out using mathematical models based on the description of the functioning of sprung and unsprung vehicle masses, as well as elastic tires. Experimental studies include bench tests of tires, shock absorbers and silent blocks of various technical conditions, as well as road studies of the kinematic parameters of the M1 category vehicle. As a result, a road method for monitoring the technical condition of shock absorbers was developed, taking into account their influence on stability indicators. Purpose – Theoretical substantiation and experimental confirmation of the method for diagnosing suspension systems by parameters related to the stability of the vehicle movement. Methodology includes experimental methods, mathematical modeling methods and numerical methods for solving differential equations. Results: experimental methods and mathematical apparatus were developed to study the influence of the parameters of the suspension system on the stability of the movement of vehicles. Practical implications: the results can be used by organizations and institutions involved in the development of diagnostic methods for vehicles.