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28TECHNICAL SCIENCES
MODEL MICROPROCESSOR DEVICE OF FOUR-WIRE SCHEME OF THE DIRECTION CHANGE
Aliev R.
Tashkent State Transport University Department «Information systems and technologies»
Aliev M.
Tashkent State Transport University Department «Information systems and technologies»
Tokhirov E. Tashkent State Transport University Lecturer Department «Information systems and technologies»
Abstract
Train traffic control systems are a complex of technical and technological systems, the most important place in which is occupied by systems for ensuring the safety of the transportation process. These include systems for electrical and dispatch interlocking, automatic blocking and locomotive signaling. Significant advances in the development and implementation of microprocessor technology have created the necessary conditions for the design of train control systems with high safety, reliability, economy and technological efficiency. A significant reserve for increasing the efficiency of railway transport is the automation of the train traffic control process based on the use of modern interval control systems with expanded functionality [1, 3].
Keywords: single-track automatic blocking, change of direction, haulage, model, microcontroller
Introduction
On sections of the railway of the Republic of Uzbekistan, equipped with automatic blocking devices with a length of 950 km. mainly uses a four-wire direction change circuit [6]. At the same time, a morally and technically outdated four-wire relay circuit for changing direction is used, which has aware of about 70%. The road has taken a course towards the modernization of automation and telemechanic systems and begins to introduce information and microprocessor technologies in transport [3]. The purpose of this research work is to study the existing four-wire circuit for changing the direction of train movement and, on its basis, the development of a visual model on a microprocessor base that simulates the operation of the circuit [4].
With a single-track automatic blocking, it is required to change the direction of movement of trains along the section in order to exclude the possibility of departure of oncoming trains [7]. To date, to change the direction of movement, a scheme is used, with the help of which two stations and the adjacent section are connected in such a way that the traffic lights in the established direction are turned on, and in the unsettled direction they are turned off; one of the stations is in the "Departing" position, and the other is in the "Receive" position. The opening of the exit traffic light for the train departure is possible only at the "Departure" station, at the "Reception" station the output traffic lights are turned off, and their opening is excluded [1]
Main part
The existing scheme involves the use of various electromagnetic relays and other bulky structures,
which, in turn, contributes to an increase in the cost of maintaining the system and for power supply. The proposed design is distinguished by the absence of electromagnetic relays and other electromechanical devices at the signal points of the haul, with the exception of travel relays that control the state of the block sections of the haul [7]. The built-in programmed microcontroller, in turn, programmatically checks a certain state of the path relay and, on this basis, implements all other dependencies [3].
There are two modes of changing the direction of movement - normal and auxiliary. The normal mode is applied only when the haul is free, the auxiliary mode is used if the haul is free, but the rail circuit of one of the block sections is faulty, which gives a false occupation of the haul. At this stage of the research work, the visual model provides for the implementation of the change of direction only in a normal mode. In the future, the implementation of the auxiliary regime is envisaged.
Before changing the direction of movement in normal mode, the person on duty should make sure that the line is free when the indicator light on the board is lit. When the control lamp lights up, it means that: all block sections of the stretch are free; weekend traffic lights at the Departure station are closed; there is no train sent by the wand key; no shunting movements are performed with access to the track. In normal mode, the duty officer at the "Reception" station changes the direction of movement. To do this, he presses a special button for changing the direction of the ChSN (NSN).
Fig. 1. Functional diagram of the visual model
The developed visual model checks only three conditions necessary for the change of direction: the freedom of all block sections of the stretch; prohibiting indication at the exit traffic lights of the Departure station; the absence of a train sent by the wand key. Figure 1 shows a functional diagram of a visual model.
Result
All the conditions and dependencies of the above presented functional diagram of the visual model are carried out programmatically, using code combinations recorded on the microcontroller of the PIC family, while in a relay-contact system, these dependencies are carried out using electromagnetic relays. This scheme assumes the use of two PIC16f877a microcontrollers at two adjacent stations, respectively. During operation, the microcontroller cyclically requests the state of all monitored objects. The microcontroller controls the corresponding indicators on the simulated board of the
station attendant in accordance with the received code combination.
The PIC16F87X is an 8-bit RISC microcontroller manufactured by Microchip Technology. This family of microcontrollers is characterized by low cost, low power consumption and high speed. Microcontrollers have built-in program EEPROM, data RAM, a wide range of supply voltages from 2.0 V to 5.5 V and are available in 40-pin packages [2]. For security applications, each PIC has a privacy bit that can be programmed to prohibit reading of the program code and data ROM. When programming, the program code is first written, checked for correctness, and then the security bit is set.
One such development for road sections is the four-wire direction change circuit shown in Figure 2.
Before the design stage of the proposed model, a schematic model was developed in the Proteus 8 Professional debugging enviromnent.
Fig. 2. Schematic diagram of direction change
The proposed scheme for changing direction on the microcontroller provides for a reduction in power consumption by 60%, costs for materials and spare
parts by 90%, and a decrease in labor costs for maintenance on average by 48%.
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References
1. A. A. Kazakov et all. Systems of interval regulation of train traffic / A. A. Kazakov, V. D. Bubnov, E. A. Kazakov: Textbook for technical schools of railway. tr. - M.: Transport, 1986.- 399 p.
2. PIC16F87X Single-Chip 8-Bit Microcontrollers from Microchip Technology: Technical Manual.
3. Tashmetov, Timur; Tashmetov, Kamoliddin; Aliev, Ravshan; and Rasulmuhamedov, Muhamadaziz (2020) "Fuzzy information and expert systems for analysis of failure of automatic and telemechanic systems on railway transport," Chemical Technology, Control and Management, 2020, No 5(29), p. 168-172
4. Guliamova M. K., Aliev R. M. Database Concept, Relevance and Expert Systems // Scientific and
educational space in the face of modern challenges. -2021.- p. 125-127.
5. Ravshan M. Aliev Intelligent track circuit development concept Journal of Xi'an University of Architecture & Technology Volume XII, Issue XI, 2020 p. 180-187
6. Tokhirov E., Aliev R. Improving the braking distance of the train before level crossing //InterConf. -2020. p. 183-186
7. Aliev, Marat; Aliev, Ravshan; Tokhirov, Ezozbek; and Nurmuhamedov, Tolaniddin (2019) "Four-Pole Rail Coefficients Of The Jointless Track Circuit In The Presence Of One Of The Ends Track Circuit Insulating Joints," Chemical Technology, Control and Management: 2019, No. 4(6), p. 89-92
TESTING I-V CHARACTERISTICS OF SILICON SOLAR PANELS UNDER SUNLIGHT
Izzatillayev K.
Master student of renewable energy source Andijan State University
Abstract
This article describes the collection of solar panels and some of the problems in this process. In addition, the volt-ampere characteristic of a silicon-based solar cell measured in natural light is given.
Keywords: silicon, solar panel, light beam, solar cell
The 0.6 V voltage and 2A current generated by the solar cells are not sufficient for consumption. In addition, solar cells cannot be used outdoors [1]. Because it is mechanically very delicate. It is assembled in the form of solar panels to protect the solar cells from external influences and increase their total current and voltage [2].
In solar panels, the solar elements are connected in parallel and in series. Cu metal tapes are widely used to connect them together. There are basically two sizes
[3]. Metal tapes with a width of 1.6-2 mm and a thickness of 0.12-0.2 mm are used to connect the first two solar cells, and the second is used with metal strips with a width of 5-6 mm and a thickness of 0.2-0.3 mm to connect each row of solar cells together [4]. Metal tapes are not only made of Cu, their surface is coated with Sn96.5 / Ag3 / Cu0.5 alloy salts to improve its chemical, mechanical and thermal properties [5].
When the solar cells are connected in parallel, their voltage does not change but the currents are added (Figure 1).
