ON THE EFFICIENCY OF SOLUTION OF THE OPTIMIZATION PROBLEM

ABSTRACT

A methodology for calculating the indicators of the payoff parameter for strategic optimization problems for railway transportation of different structure, type and type of cargo on railway sections is proposed.

АННОТАЦИЯ

Предложена методика расчёта показателей параметра выигрыша для задач оптимизации стратегического типа при железнодорожных перевозках различных по структуре, типу и виду грузов на участках железных дорог.

Keywords: algorithm, solution, freight traffic, locomotive, payoff parameter, carriage, optimization problem, haul, parking, efficiency.

Ключевые слова: алгоритм, решение, грузопоток, локомотив, параметр выигрыша, вагон, задача оптимизации, перегон, стоянки, эффективность.

Strategic-type optimization tasks for the locomotive complex of railways, including Uzbek ones, are aimed at achieving the greatest efficiency in the use of the locomotive fleet in real conditions for organizing the transportation of goods and passengers by rail.

In [1] it is shown that for railway transport in general and its individual sectors (services, departments), the criterion for evaluating the effectiveness of work can and should be taken as the gain parameter B - annual reduced national economic costs.

The payoff parameter B should be taken (accepted) for a given freight traffic G t net, which can be written as follows [2]:

Э_г = Э + Э₁ + Э₄ + Э_к                                                                (1)

where Э - annual operating costs; Э1 - the share of annual deductions for capital costs for rolling stock with an appropriate payback period; Э4 - reduced costs associated with the cost of cargo on wheels, the speed of its delivery and the standard payback period; Эк is the annual present share of capital investments on the site (excluding rolling stock) to improve working conditions or expand the volume of rail traffic.

We believe it is necessary to dwell on the accepted order of counting some values necessary for calculating the mentioned gain parameter for strategic-type tasks - the annual reduced national economic costs for hauling the railway section.

With the net travel time specified in the initial data along the considered stage -  and the coefficient of sectional speed in relation to the running - βу the sum of the total idle time of the train at intermediate stations and additional time for acceleration - deceleration related to the i - th stage will be

_i =                                                      (2)

The idle time of the train at the precinct stations, referred to the haul length  xi, km with the length of the counting section Lc, km can be taken

                                                                 (3)

and the corresponding time for acceptance - delivery of a locomotive (diesel locomotive, electric locomotive) by locomotive crews

                                                               (4)

where ty - total stop time at local stations of the account section under consideration, h; tб - total time spent by locomotive crews for acceptance - delivery at the account section, h

If, based on the experience of work or the train schedule, to reveal the average idle time of trains at intermediate stations , as well as acceleration – deceleration , then the stops assigned к i - mu haul will be

stops                                            (5)

Given the known average total idle time of the locomotive in the main and circulating depots per revolution , the value of this time, related to the i -th stage will be

                                                           (6)

where Ln - arm length of the chainless operation of the locomotive, km.

Locomotive turnaround time, referred to к i - mu haul, assuming =  will be

                                                  (7)

where  = - additional time related to the haul, hours

The corresponding cost of locomotives on the haul will be

                                                      (8)

where пс - daily number of trains in the considered direction; - coefficient of conversion of the operating fleet into inventory.

The required number of cars of the inventory fleet, assigned to the i-th haul will be

                                                     (9)

Number of wagons depending on traffic conditions

                                                  (10)

and their number, depending on the parking at the stations

                                          (11)

where пв - number of cars on the train; Кв - coefficient for converting the operated fleet into inventory; - average sectional speed related to the i-th stage, km/h; 0.0415 is the share of car-hours of movement, taking into account the number of cars in trains located at the stations of the section [3].

Thus, the values will be obtained  и , which are necessary for calculating the reduced costs for capital investments in rolling stock and its renovation.

The value of stops zi is used to determine the cost of parking associated with the time and energy costs of funds.

As a result of the foregoing, the calculation of the value of the annual reduced national economic costs for the haul is carried out on the basis of expression (1), attributing all calculations of its terms to the haul.

Reference:

1. Ablyalimov O. S. On the classification of process optimization problems [Text] / O. S. Ablyalimov // Universum: technical sciences: electron. scientific magazine 2020. No. 8 (77). pp. 20-22. DOI: 10.32743/UniTech.2020.77.8-1.
2. Ablyalimov O. S. Economic indicators of the efficiency of locomotives in operating conditions [Text] / O. S. Ablyalimov // Universum: technical sciences: electron. scientific magazine 2020. No. 9 (78). pp. 76-79. DOI: 10.32743/UniTech.2020.78.9-1.
3. Tikhonov K. K. Technical and economic calculations in the operation of railways [Text] / K. K. Tikhonov // Monograph. – M.: Izd-vo MPS, 1962. – 252 p.