No abstract

The paper considers a method for calculation and evaluation of an automated brake proportioning system and it also describes assessment of efficiency while using cohesion forces of an automated system during vehicle braking process (MAZ 256200 taken as an example). A method for efficiency estimation of the vehicle braking equipped with an automated brake proportioning system is graphically presented in the paper. A comparable analysis has been made in order to evaluate vehicle braking efficiency in three various conditions of its wheel motion during braking process. The paper contains description of braking processes for a vehicle at its idealized braking, at braking with an operating automated system and at braking with blocked wheels. Mathematical dependences have been proposed and they make it possible to calculate a coefficient of cohesion forces used by an automated brake proportioning system on the basis of time parameters for vehicle braking process. The proposed mathematical dependences take into account design peculiarities of the automated system, i.e. a diagram of modulator arrangement on axes of the vehicle. The executed analysis for calculation accuracy of the coefficient pertaining to use of cohesion forces of the automated system with and without taking into accout rolling force resistance of the vehicle wheels has demonstrated a possibility to apply the proposed calculation methods for carrying out auto-technical expertise while investigating road-traffic accidents involving transport facilities equipped with such systems as ABS. The paper proposes a dependence for identification of a vehicle braking distance on the basis of the coefficient on use of cohesion forces by the automated brake proportioning system. The executed experimental investigations on both test and serial models of the automated brake proportioning system have allowed to justify theoretical discussions concerning application of tyre-road adhesion in the operational process of the vehicle brake proportioning system. The investigation results have shown high efficiency of the test automated brake proportioning system developed by Chair of Automobiles in the name of A. B. Hredescul at Kharkiv National Automobile and Road University under the following braking conditions: dry road surface and compacted snow cover.

No abstract

No abstract

Problem. For an hour, in the scientific-methodical recommendations of the ship-experts, it is installed in the scientific-technical literature of the day-to-day parameters of galvanizing of vantage, bug-capable transport equipment, so that it is inaccurate to introduce autotransport equipment for the eastern part to inaccurate zasob_v unique road transport suit. Goal. The value of the function of galvanizing large transport bridges on the basis of the coordinates of the position to the center of the heavy transport, realizable values, which are realized between the tires and the supporting surface, as well as the support for the rear axle of the transport bridges. Methodology. The approaches adopted in the work to solve this goal are based on the theoretical foundations of braking multi-axle vehicles, the scientific provisions of elastic deformations of pneumatic tires of automobile wheels, geometric and weight parameters of a wheeled vehicle. Results. The equations that allow to calculate the value of the braking coefficient of multi-axle vehicles based on the coordinates of the position of the center of gravity, the realized couplings between the tires and the bearing surface, as well as the load distribution between the respective front and rear axles of the vehicle. Rivnyannya is assigned, which allow the positioning of the coordinates to the center of the car of a multi-axle wheeled transport vehicle for both front and rear axles. The calculation schemes of the position of the coordinates of the center of mass for two-axle, three-axle and four-axle with different axle layout are presented in graphical form, which give a general idea of the mass distribution between the front and rear axles of the vehicle. Originality. Presented in a graphical view of the layout of the positioning of the coordinates to the center of the car for a two-axle, three-axle and one axle with a small layout of the bridges, which give a far-reaching display of the space between the front and rear axles of the transport vehicle. Practical value. The results can be recommended by the experts-auto technicians in the development of technical capabilities for the drivers of vantage transport means, uniqueness of the road-transport usability.