Spiryagin M. The improvement of adhesion between wheels and rails by means of the modernization of the control system for railway vehicles.

In the thesis work, review of publications, articles and patents for solving a problem of adhesion with usage of control and adjustment system for railway vehicles was made. Document analysis shows that the most of companies use asynchronous tractive motors for solving this problem and the same method for optimization of adhesion for railway vehicles is used. The method is based on the determination of a value for wheel pairs’ acceleration, which is an indicator of wheels’ slip. However, as a rule, the method of the control for absolute slip velocity is applied too. The basis for the determination of a value for absolute slip velocity is artificial imitation of a value for vehicle velocity. The control strategy analysis shows that most of the methods have the same approach to a problem for slip detection. A lot of strategies use signals of vehicle velocity and the adhesion as input signals for their control system. The differences are how to use and interpret these signals. Usage of microprocessor control systems allows for the application of different control strategies by means of the software change. The mathematical model of the interaction between wheel pairs and rails for different adhesive conditions and arbitrarily assigned position of wheel pairs relatively rails was made. Realization of adhesive force for tractive, starting and breaking modes was researched. Patterns for the definition of adhesive force depending on relative slip of wheel relatively rail for different adhesion conditions were developed. This model is a basis for the method of determination tractive and braking properties for railway vehicles on design stages and gives input characteristics for a development of the control strategies for microprocessor control system with asynchronous tractive motors. Calculation results of the mathematical model of the interaction between wheel pair and rails were used for developing of DEL-01 train modeling. In this model, mutual work of mechanical and electric parts of vehicle has been taken into account. The software for this mathematical model was created by using of programming language C. The values of adhesion forces for different adhesive conditions were calculated. Adequacy verification of the given model has been proved by comparing the result of computation with experimental data. The structure of microprocessor control system, which improved tractive and dynamic characteristics of railway vehicles, was proposed. The improvements are reached by means of optimization for cooperation using of pneumatic and electric braking systems, adjustment of pushing efforts for braking shoes on a wheel, adjustment of braking torques for tractive motors by using the criterion for adhesive force and by using the maximum possibilities of tractive motors in tractive mode. The principles and algorithms for control and adjustment of tractive electricity transmission were developed: the algorithm of slip velocity adjustment for the each axle, the algorithm of realization tractive and braking characteristics for railway vehicles and the algorithm for the operation of the sand system. The simulation model of the proposed principles and algorithms was performed in MatLab-Simulink software product. The sanding device of the sand system was developed for increasing the efficiency by means of the control of its productivity and for the prevention of the sand caking. The results obtained have been used in choosing and realizing the parameters of the microprocessor control system of tractive electricity transmission, which was created for DEL-01 train at the following enterprises – HC "Luganskteplovoz" and JSC "Elektrovazhmash". The test data of the created microprocessor control system showed that the proposed principles and algorithms are reasonable.