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A method of vehicle straight angle motion relative its axial axis by turning the front wheels and simultaneous braking of the external side wheels is offered. The equation describing the condition of four-wheel drive vehicle crab motion is obtained. The purpose of the research is to determine the law of control of torque on the wheels of the car, the realization of which makes crab motion possible. For realization of the aim, the following challenges were solved: the torque difference on the driving wheels (the braking torque on the outside wheel) that provides “crab motion" is determined; an analysis of the operational factors influences and design parameters of the vehicle, on the magnitude of the required torque difference, was conducted.

The dynamic distribution of normal reactions between the axles of the wheeled tractor has a significant impact on the stability against skidding and the wheeled tractor braking effectiveness. At the same time, the clarification of the normal reactions distribution between the axles allows to choose more rational braking forces distribution between the axles. It is shown that the best way to ensure the highest braking efficiency is the braking mode when the rear wheels of the tractor are at the blocking limit. An assessment of the expediency of installing brake mechanisms on only one axle of the tractor was made. The increase of braking efficiency of wheeled tractors with all brake wheels provided that they ensure directional stability is considered. The laws of braking forces distribution between the axles of wheel tractors for different sequence of wheels locking are determined.

One of the reasons for the large number of road accidents on highways in Ukraine [1] is the instability of the braking properties due to the unstable characteristics of the brake mechanisms’ friction pairs. The manufacturer produces new automobiles with installed brake pairs (brake pads and their counter bodies), which have passed long-term tests for the stability of the friction coefficient and braking forces distribution of between the axles. This ensures the compatibility of the friction pairs characteristics for front and rear brake mechanisms according to the criteria of heat resistance. During operation, instead of worn-out brake pads, brake discs and drums, drivers can purchase new ones, manufactured as spare parts. However, in the well-known literature there are no methods that allow to check the compatibility of the friction pairs characteristics for front and rear brake mechanisms according to the criteria of heat resistance.

The solution to the problem of stability of a multi-axle vehicle during braking is connected with the determination of the dynamic distribution of normal road reactions between the axles. To assess the stability of the vehicle is used as an indicator of the stability factor representing the ratio of the stabilizing moment to moment, the perturbing skid. When the values of the stability coefficient is greater than or equal to unity, the movement is stable, and otherwise it is unstable. For a multi-axle vehicle, determining the dynamic normal road reactions on the axles is possible after disclosing the static uncertainty of the physical model of the car, which is a multi-support beam. The solution to this problem involves the use of the "three sigma" rule.

The intensive development of tractor-building industry in the world has led to the widespread use of wheeled tractors and tractor trains in transportations on public highways. This requires an increase of engine capacity and speed of tractor trains, as well as strict demands for their braking systems. The formation of the necessary braking properties of wheeled tractors and tractor trains on their basis should be carried out at the design phase, taking into account a wide range of aggregated machines and tools. Blocking the wheels of the trailer with different sequence of their blocking and blocking the wheels of the tractor has significant impact on the total braking force, deceleration and stability of the tractor train. It is advisable to take this into account when modeling the braking process of a tractor train.

Remote monitoring is the most important stage in controlling the technical condition of a modern vehicle under operating conditions. Remote control of the technical condition involves using V2I systems in order to form and apply individual maintenance and repair systems. V2I information model developed in the article is characterized by vehicle digital field, limited by regulatory rules, with means for technical condition parameters monitoring and components of infrastructure for each vehicle monitoring. The article describes the peculiarities of V2I information system and the process of monitoring and evaluating the vehicle technical condition under operating conditions with the possibility of forecasting. The monitoring information system is designed to ensure the vehicle efficient operation under non-stationary operating conditions, with continuous consideration of information from road and transport infrastructure.

The results of this work is allowed to identify a number of cybersecurity threats of the automated security-critical automotive systems, which reduces the efficiency of operation, road safety and system safety. Wired or wireless access of the information networks of the modern vehicles allows to gain control over power unit, chassis, security system components and comfort systems. According to the evaluating criterion of board electronics, the presence of poorly-protected communication channels, the 75% of the researched modern vehicles do not meet the minimum requirements of cybersecurity due to the danger of external blocking of vital systems. The revealed vulnerabilities of the security-critical automotive systems lead to the necessity of developing methods for mechanical and electronic protection of the modern vehicle. The law of normal distribution of the mid-points of the expert evaluation of the cyber-security of a modern vehicle has been determined.