Digital control models - the basis transportation logistics

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DIGITAL CONTROL MODELS - THE BASIS TRANSPORTATION LOGISTICS

Terenetyev А.V., Grand Ph.D. in Engineering, Prof, at the Department of «Machinery Parts and Theory of Mechanisms», Moscow Automobile and Road Construction State Technical University (MADI), Russia, Moscow

Yevtyukov S.S., Ph.D. in Engineering, Assos. Prof. at the Department of «Ground transportation machinery», Saint-Petersburg State University of Architecture and Civil Engineering, Russia, Saint-Petersburg

Karelina Е.А.,

Ph.D. in Economics, Assoc. Prof, at the Department of «Foreign Languages», Moscow State University of Technology «STANKIN» Russia, Moscow

Terentyeva V.A., Ph.D. student, Saint - Petersburg Mining University Russia, Saint-Petersburg

Ershov V.S., student, laboratory assistant Department of «Machinery Parts and Theory of Mechanisms» Moscow Automobile and Road Construction State Technical University (MADI) Russia, Moscow

Abstract

A significant number of automated control systems used today are based on the relational principle, which implements a subject-oriented approach to management in the system, when the means of interaction are tables or stored procedures. In this case, the control is carried out according to the accumulated statistical data, that is, laws that are, as a rule, of a stochastic nature. The clear advantage of an alternative - object-oriented approach is that attribute conversion mechanisms allow to build derived objects and structures based on basic ones, thereby creating a model in a more complex subject area with the necessary properties, providing the possibility of continuous analysis and making changes if necessary. Together with the use of digital technologies this approach allows to design and modernize transport and logistics systems as subsystems of intelligent transport systems.

Key words: control system, object-oriented approach, transport and logistics system, digital technologies, databases.

Transport and logistics systems (TLS) are formed based on the peculiarities of modern ideas about the object of management. The object of control is understood as a traffic flow, as a set of moving vehicles, with specific indicators inherent in it. In this case, the traffic flow has the following properties: unsteadiness, stochasticity, stability, inertia, interconnectedness, insufficient controllability.

This interpretation of the control object in the TLS, which dominates today in the design and modernization of transport systems in large cities and global transport infrastructures, is increasingly inconsistent with market economic mechanisms. In which each interested explant of the transport system (freight carriers, owners of transport and warehouse complexes, municipal authorities, etc.) optimizes "their own transport logistics and economy", which leads to a transport situation where the potential of TLS does not satisfy everyone.

An alternative to this approach is the use of mechanisms for synchronous or complex optimization of individual parameters of the components of the traffic flow: freight traffic, passenger traffic, as well as elements of the transport infrastructure (parking lots, transfer hubs, freight terminals, etc.). The implementation of this alternative will allow:

- to reduce the total mileage of freight rolling stock;

- to use more efficiently the capacities of both the street and road network (UDS) of megalopolises and the TLS infrastructure as a whole;

- to differentiate in time and space (optimally redistribute) transport flows of goods and passengers.

In order to effectively manage such an unstable object as a traffic flow, transport science is constantly looking for more and more new approaches. Control systems have gone from local rigid one-program regulation in separate sections of the TLS to automated traffic control systems (ACS TP), using complex algorithms and principles of artificial intelligence. Adaptive systems using various self learning algorithms, systems simulating the behavior of living organisms [1] and systems based on neural network technologies or artificial intelligence [2, 3] have become a modern stage in the development of process control systems operating on the principle of feedback with flow.

A milestone in the development of automated process control systems was the development of the document: "Coordinated Freeway and Arterial Operations Handbook" in 2006 [4]. This manual describes the issues of coordinating the work of control systems on the highways and adjacent road traffic systems. However, it does not contain a description of the technical aspects of the coordination process, but focuses on a description of the planning process, the possibilities for coordinated management, the strategies used, etc. The main objective of the coordination principles described in this manual is to ensure the reliability and predictability of traffic in the so-called “corridors”. In this case corridors mean a section of a highway and adjacent city streets that ensure the movement of vehicles through a certain territory. It is recommended that the planning of a coordinated corridor management system start with a system-wide design, i.e. with the development of a regional plan for the development of such corridors. After the formation of a regional development plan for corridors with integrated management for the implementation of a specific project, the following sequence of actions is proposed:

Study of the problem.

Analysis of the organizations involved.

Formation of goals, objectives and criteria for project evaluation.

Development of the concept of the corridor.

Formation of a list of possible strategies and management scenarios.

Evaluation and selection of strategies and scenarios.

Development of an implementation plan.

Detailed design.

Construction (implementation).

Operation and maintenance.

Analysis of work and suggestions for improvement.

In nowadays the processes of integrating the transformation of TLS into Intelligent Transport Systems (ITS) in the United States continue on a systematic basis, and regular work is carried out to track the best solutions and exchange experience between road agencies of different states [5]. In addition, there is a tendency to move to the so-called "active management" (Active Traffic Management) [6,7]. This approach assumes a more intensive impact on the behavior of traffic flows based on modeling and predicting changes in its parameters, which requires full integration of all control systems.

It should be noted that the success of the implementation of coordination of management of heterogeneous systems depends not only on the integration of technical aspects of TLS, but, possibly to a greater extent, on the relations between organizations, which can both facilitate and hinder the solution of the task, as well as a number of other obstacles [8]. The widespread deployment of infrastructure, integrated urban TLS cannot happen without addressing these non-technical issues. Transport officials at the federal, regional and local levels need to understand that focusing on the integration and deployment of ITS requires not only technical issues, but also requires institutional innovation, which is in some ways more complex.

Coordination of control actions is considered an attribute of a full and complete control process. This level occurs when individual elements of the system begin to develop control actions based on the incoming information in the interests of the entire system as a whole. The stage of coordinating control actions requires maximum efforts in overcoming organizational and technical barriers, since, as a rule, the creation of a single communication computer network is required. At this stage, each participant must correlate their decisions with the general management concept. That is, the concept of a control object is transferred from a generalized (aggregate) traffic flow to a separate control element (a separate passenger, a separate consignment, a separate vehicle).

The integration of TLS components is carried out by transferring information between individual vehicles and TLS elements at the present. In one of the studies, 32 links are identified between the components of the ITS [9]. Figure 1 shows a diagram of connections and data transmitted over them between TLS components.

Fig. 1 - Relationships between TLS components

It can be stated that the completed management process in the ITS which meets the current level of development of scientific and technological progress and productive forces requires:

Creation of a unified communication and computer network for information flow control.

Development and application of object-oriented models for controlling physical objects of movement in the transport network, which form the optimal trajectories of movement of the latter [10].

In a general consideration of the issues of interaction of objects in a network, connected with each other by a number of various relations (analytical connections), it is necessary to develop algorithms that are able to maintain integrity relations between objects. Modern approaches to the creation and provision of reliability and security of information systems (IS) lead to the fact that all the main solutions in the field of organizing information exchange processes have a client-server architecture. This approach allows you to restrict access to confidential information by concentrating all the functions of direct data management in a single center. As a rule, various database management systems (DBMS) are used as server software. A significant number of used DBMS are based on the relational principle that implements a subject-oriented approach (SOA) to the management of procedures in the system, when the means of interaction are tables or stored procedures. In this case, management is carried out by a certain set of objects through the definition (accordin g to the accumulated statistical data) of regularities, which, as a rule, are of a stochastic nature.

The main disadvantage of this relational model of interaction in complex systems based on a domain-specific approach is:

The designed system, as a set of tables, is very often difficult to analyze and understand processes.

The growth of the complexity of the system makes it impossible to fully or reliably track all the necessary places and procedures for the implementation of changes, and the process of development of the system itself is transformed into poorly controlled or uncontrollable.

The basis for the formation of digital transport logistics as a subject of management in complex TLS is an object-oriented approach (OOA). With an object-oriented approach, an action program should represent not only a description of objects and their properties in the form of criteria, and relations between them in the form of goal-setting, but also the ways of their interaction (methods) in the form of operations on objects [11]. A clear advantage of the object-oriented approach is the conceptual proximity in any subject area to the arbitrary structure and purpose of the system. At the same time, the mechanisms for transforming attributes or methods should allow building derived objects and structures on the basis of basic ones, thereby creating a model in a more complex subject area with the necessary properties, providing the possibility of constant analysis and making changes if necessary. In this case, objects and methods are polymorphic, which makes the developed software more versatile and flexible. Despite the obvious advantages of the object-oriented approach, object-oriented control systems have not yet received mass distribution. At the same time, hybrid object-relational DBMS have become widespread, which partially use object-oriented principles of working with data, but at the same time, the data storage representation is performed when implementing the relational model.

algorithm mechanical algorithm system

References

1. US Public Law 102-240, Intermodal Surface Transportation Efficiency Act of 1991

2. Arterial Control and Integration // WS DOT, 1990

3. History of Intelligent Transportation Systems // U.S. department of transportation, report FHWA-JPO-16-329, 2016.

4. Coordinated Freeway And Arterial Operations Handbook // FHWA, 2006.

5. Highway Traffic Operations and Freeway Management: State-of-the- Practice // U.S. department of transportation, report FHWA-OP-03-076, 2013.

6. Synthesis of Active Traffic Management Experiences in Europe and the United States // FHWA, 2010.

7. Active Traffic Management for Arterials // National Cooperative Highway Research Program, 2013.

8. Inter-jurisdictional Coordination for Traffic Management in “Large City Technical Exchange And Assistance Program” // New York University, 2000.

9. Building the ITI: Putting the National Architecture into Action, Mitretek Systems, FHWA, April 1996.

10. Evtiukov S., Karelina M., Terentyev A. A method for multi-criteria evaluation of the complex safety characteristic of a road vehicle // Transportation Research Procedia. - Saint Petersburg: Elsevier B.V., 2018. - С. 149-156.

11. Grib V.V., Karelina M.Yu., Petrova I.M., Filimonov M.A. Development of an algorithm for predicting and monitoring the resource of mechanical systems // Modern problems of the theory of machines. - 2013. - No. 1. - p. 77-79.

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