Microprocessor Control System Research Articles

Analysis of designs of drive mechanisms of medium voltage vacuum contactors

One of the main elements of medium voltage vacuum contactors is the drive mechanism, which includes an electromagnet. In existing models of contactors, two types of electromagnets are used: monostable non-polarized electromagnets with a return spring or bistable polarized without a return spring. It was found that the use of polarized electromagnets in combination with a microprocessor control system expands the functionality of the contactor and makes it possible to reduce the energy consumption of the electromagnets, their overall dimensions and weight, while achieving significant armature holding forces. The designs of polarized electromagnets, which were developed at the Department of Electrical Apparatus in recent years, are considered. Their shortcomings were identified and a new design of a bistable polarized electromagnet was proposed, a computer model of the contactor developed in the KOMPAS-3D package was built. The counteracting characteristic of the mechanical system of the contactor, which is brought to the axis of the electromagnet and the stroke of the armature, is constructed, the forces that must be created by the electromagnet in the on and off position for reliable operation are determined. The FEMM model of the experimental sample of a bistable polarized electromagnet was developed and the calculation was carried out in the on and off positions. The possibility of using a new design of an electromagnet in a medium-voltage vacuum contactor has been confirmed.

Analysis of the operation of the microprocessor control system of a bridge crane using optimum control laws

This work presents the results of studies on the influence of the error of the main parameters of the bridge crane on the quality of optimal control. The quality of control refers to the exact positioning of the load at the stopping point and the magnitude of the final fluctuations of the load after the crane stops. The concept of optimal control is based on L.S. Pontryagin's maximum principle, which is when the goal is achieved by switching the acceleration-braking control of the load suspension point according to a specific algorithm. To achieve the maximum speed of operation of the crane, certain restrictions and conditions have been removed, namely, the refusal to eliminate load fluctuations during crane acceleration, which simplifies the subsequent elimination of load fluctuations during crane braking. However, this is an unnecessary waste of time, and therefore, acceleration is carried out at the maximum possible acceleration without eliminating load fluctuations. Of course, at the same time, significant fluctuations in the cargo occur, and they continue throughout the entire time the crane is moving. Moreover, the final goal is achieved only at the end of the cycle by switching the acceleration-deceleration modes - the cargo is delivered precisely to the specified point without fluctuations after the crane stops. A PC program that generates optimal control laws for a specific crane has been developed. This program can be used for any lifting machine where the suspension point moves in a straight line, and flexible load suspension is used, such as overhead or gantry cranes, hoists, etc. The results of the research were tested on several objects: a 0.5t crane, a 5t bridge grab crane, and models of bridge cranes. In each case, a good coincidence of theoretical and experimental results was observed, resulting in effective management of the object. The original microprocessor system implemented the optimal control laws, built first based on the MKP-1 microcontroller and then based on Arduino. However, a good result is guaranteed only if the fundamental parameters of the crane coincide with the theoretical ones. This is not easy to achieve during the actual operation of the crane. They vary within a specific range. The article examines how the error in each of the main parameters of the crane affects the result and how the control system can be improved to reduce the negative impact to a minimum. Keywords: optimal control, elimination of load fluctuations, accurate positioning, crane, microprocessor, reloading cycle

CONCEPT OF IMPLEMENTATION OF PRECISION MICROPROCESSOR CONTROL SYSTEM OF COLLECTOR ENGINE OF CNC MACHINE

An emerging trend in recent decades is the increasing role of CNC equipment, which has already become one of the main types of equipment in significant portions of modern technological lines. This is attributed to both the complication of technological processes and the rising demands for product quality, as well as the increased productivity and functionality of modern microprocessor systems. It is worth noting that the DC motor and its electric drive, which can operate on both direct and alternating current, occupy a significant niche in the social production system and deserve special attention. One of the key features of modern scientific and technological progress is the wide use of microelectronics in various branches of the national economy, which is constantly growing. The role of microelectronics in the development of social production is determined by its versatile capabilities in solving various tasks and its deep influence on culture and everyday life of a person. Currently, special attention is focused on the introduction of microprocessors that solve the tasks of automating the control of mechanisms, devices and equipment. Adaptation of microprocessors to specific tasks is usually carried out by developing appropriate software, which is then loaded into the device's memory. Hardware adaptation, in most cases, is carried out by connecting the necessary integrated circuits and organizing input-output corresponding to the problem being solved. These characteristics ensure high flexibility of such systems, which allows you to quickly adapt production equipment to new technological conditions. The article proposes a concept for implementing a precision microprocessor control system for a CNC machine's DC motor, implemented on the basis of single-chip microcomputers, characterized by increased reliability due to the reduction in the number of serial links. A methodology for implementing a precision microprocessor control system for a CNC machine's DC motor has also been developed, the application of which will significantly simplify the design process and reduce the time required to build such a system.

Совершенствование структуры системы управления электроприводом переменного тока с асинхронными тяговыми электродвигателями на основе микропроцессорных вычислительных устройств

Objective: consideration of the issue of improving the structure of the automatic control system for an AC traction electric drive with asynchronous electric motors. Abandonment of the physical wheelset speed sensor. An overview of the performance of microprocessor computing devices at the beginning of their appearance in the USSR. An overview of the performance parameters of foreign and domestic microprocessor computing devices both abroad and in Russia. Comparison of the performance of computing devices at the time of their appearance and at the present moment. Methods: collecting information on possible options for improving the structure of the automatic control system for an AC traction electric drive. Collecting information about domestic microprocessor computing devices used at the beginning of their appearance. Collection of information on domestic and foreign microprocessor computing devices used today. Comparison of performance parameters of domestic microprocessor computing devices used at the beginning of their appearance with devices used today. Results: the possibility of analyzing the implementation of a microprocessor control system by a traction electric drive with asynchronous electric motors without using a physical speed sensor using a state observer based on an adaptive Luenberger filter is indicated. Practical importance: it consists in obtaining economic benefits from the elimination of the physical speed sensor of the wheelset as a result of the elimination of production and maintenance costs.

Application of electric traction drive for the modernization of locomotives with hydraulic power transmission

The issue of updating the locomotive fleet of industrial enterprises by modernizing outdated diesel locomotives with hydraulic power transmission was considered. The analysis of existing modernizations shows the possibility of using traction electric drive while preserving the original group drive of wheel pairs. This approach is used by manufacturers when updating outdated and creating new diesel locomotives and traction modules for rolling stock. A possible option is the use of single-motor carts. Previous studies on the choice of the type of wheel pairs drive were analyzed and it was established that the use of a group drive of wheel pairs provides the possibility of realizing high traction forces without additional devices, and the drive itself has a lower cost. This determines the expediency of using a group drive of wheel pairs when modernizing diesel locomotives with hydraulic power transmission. To realize these advantages, it is necessary to use a traction electric drive based on electromechanical alternating current converters. This approach was implemented by Mykolaiv Locomotive Repair Plant LLC during the modernization of TGM6 diesel locomotives. The diesel locomotive is intended for shunting and hauling operations, as a result of which it was assumed during the design that the traction force when moving is equal to 320 kN, the continuous traction force is 300 kN, and the maximum speed is 50 km/h. The power plant consists of a modern Cummins diesel engine and a synchronous generator. A frequency-controlled asynchronous traction electric motor is used to drive the wheel pairs. Power and control of the electric motor is carried out using a voltage inverter. Diesel locomotives use a controlled electric drive of cooling motor-fans, and semiconductor converters are used to power auxiliary systems. The locomotive and its systems are controlled by a microprocessor control system. The application of the traction electric drive based on the asynchronous electric motor provided the estimated efficiency of the diesel locomotive and the efficiency of the diesel power at the nominal power and the estimated speed of the long-term mode, equal to 6 km/h, are 0.312 relative units and 0.69 relative units, respectively. The analysis of ways to improve the traction electric drive to reduce the consumption of fuel and energy resources was carried out. It was determined that the use of a power plant with energy storage and the use of two traction electric motors for the group drive of wheel pairs may be expedient

Methodological approach to recovery correct functioning of embedded systems at the level of programmable element base

The article proposes a methodical approach to restoring the proper functioning of specialized microprocessor control systems at the level of the programmable element base. This approach includes two stages. At the first stage, the main task of technical diagnostics is solved, namely the recognition of the state of a specialized microprocessor system, which includes: assessment of the technical state, forecasting, detection and localization of malfunctions. This task is solved by detecting errors in the operation of a specialized microprocessor control system, which are caused by the failure and failure of digital devices, errors in software, or other reasons, using existing control methods, as well as localization of malfunctions of a specialized microprocessor control system, using methods of test and functional diagnostics digital devices that are part of the system under consideration. At the second stage, the correct functioning of the specialized microprocessor control system is restored by reconfiguring its internal structure at the level of logical elements. At the same time, the reconfiguration of the internal structure is based on the position of the prescriptive theory, which considers the issue of purposeful management of objects of various nature, which are in a state of "conflict" with other objects. The implementation of the proposed approach in the future can be the basis for the design of active fault-tolerant systems that will be able to counteract failures a hardware and software nature as a result of internal or external adverse actions.

The analysis of principles of continuously variable transmission of tractors

BACKGROUND:Modern agricultural activity requires the use of hightech equipment such as, in particular, a multifunctional tractor, which, according to actual trends, should be an autonomously controlled mobile power plant. In modern tractors, meeting current requirements, multiflow shaft-planetary gearboxes with cumulative effect are used.
 AIMS:Comparison of the operation principles of two types of automatic tractor transmissions: with hydrostatic drive and with electromechanical drive.
 METHODS:During the research, a literature review of printed and online publications with technical description of the transmissions of the considered design was carried out.
 RESULTS:The operation principles of two types of automatic tractor transmissions were considered: with hydrostatic drive (Fendt VarioDrive) and with electromechanical drive (Ruselprom-electroprivod LLC).
 The operation principle of the Fendt VarioDrive transmission (planetary multiflow transmission with mechanical and hydrostatic branches) consists in dividing the torque coming from the internal combustion engine by a planetary gearbox into mechanical and hydrostatic branches, followed by summation of flows by a collecting shaft. The change in the gear ratio and movement direction of the tractor is controlled by the ECU by means of controlling the hydrostatic branch of the transmission. The transmission is nominally continuously variable due to the absence of gears as such.
 The set of traction electrical equipment of the transmission developed by Ruselprom- electroprivod LLC, installed on a tractor, includes:
 an synchronous motor generator with a power converter and a microprocessor control system;
 a traction asynchronous motor of the central drive with a power converter and a microprocessor control system;
 a DC-DC converter for energy supply of auxiliary equipment.
 power converters and a DC-DC converter are integrated into the power electronics unit;
 a top-level controller with controls and indicator panel in the drivers cab.
 The control system of the electromechanical transmission provides with full control of its operation and the functioning of the internal combustion engine. The operation principle of the system is based on the essentials of hybrid transport operation. Tractor movement is possible in one of two ranges: range 1, operational (0...18 km/h) and range 2, transport (0...42 km/h)
 CONCLUSIONS:Due to the modern concept of electric drive units, layout solutions with an electromechanical drive having an electric generator in their design are more promising and applicable in the future, especially for trailed equipment.

ЗАСТОСУВАННЯ АСИНХРОННОГО ЕЛЕКТРОПРИВОДА З КЕРУВАННЯМ ЗА РЕАКТИВНОЮ ПОТУЖНІСТЮ

The practical issues of using an asynchronous electric drive with reactive power control with ensuring the independence of the load and over load capacity from changes of induction motor parameters, uninterrupted diapason of speed regulation, including zero, fast regulation and simplification of the microprocessor control system are considered .It is show what it may be to implement. References 8, figures 6.

Model-Based Design of Microprocessor Control System for Direct Current Servo Electric Drive

Model-Based Design of Microprocessor Control System for Direct Current Servo Electric Drive

Improving the temperature resistance of traction electric motors using a microprocessor control system for modern locomotives

Temperature control of traction electric motors running on direct current with the help of a modern microprocessor-based locomotive control system is analyzed in the paper. Development of a methodology for calculating the temperature of the windings of traction electric motors operating on direct current, based on a modern control system has been discussed. To determine the dependence of the temperature of traction motors on the motion profile and weight of the rolling stock.

Model-based design of microprocessor control system for direct current servo electric drive

Model-based design of microprocessor control system for direct current servo electric drive

Определение сопротивления в цепи тяговых электродвигателей по данным микропроцессорных систем управления

Purpose: To develop methodology for determining the actual resistance of traction electric drive (TED) circuits of a locomotive with electric power transmission and with refined calculation of voltage losses of a collector-brush apparatus according to microprocessor control system data. These data are necessary for calculating actual traction characteristics of a locomotive as well as its braking characteristics in electric braking modes. Methods: Methods of electric machine theory, statistical processing and regression analysis of experimental data were used. Results: Based on the statistical analysis of registration data of on-board diagnostics subsystem of 20 sections of 2TE116U and TEP70BS diesel locomotives, methods for determining resistance factual value for traction electric drive circuit as well as methods of refined calculation for voltage losses in a collector-brush apparatus are proposed and justified. The hypothesis on distribution normal law for the value of resistance and the possibility to use its mathematical expectation as an estimated value is confirmed. The limits of resistance possible changes for TED circuits of diesel locomotives 2TE116U and TEP70BS have been established. Practical significance: The results obtained allow us to clarify energy loss amounts in a locomotive traction drive when calculating its traction and braking characteristics. Data on the limits, allowed in exploitation, of active resistance change for TED serviceable chains may be used for operative diagnostics of locomotive power circuit.

Математическая модель задатчика перемещения электропривода и разработка его программного обеспечения

Various computational algorithms to perform automatic control of motion are widely used in microprocessor control systems of electric drives. The requirements for such algorithms are the minimum execution time, the minimum amount of calculations, the compactness of the software, the convergence in the statics and dynamics of the control system. It ensures the stability and accuracy of coordinates control. The above-mentioned issues are applicable to the computational algorithm to develop a S-shaped trajectory of the electric drive by the position master unit. The position master unit based on the well-known mathematical model has some disadvantages that limit its use. They are incorrect calculation of the trajectory depending on the speed, acceleration, and sampling interval, as well as the self-oscillatory processes in case of the output and intermediate coordinates. As a result, it leads to a decrease of the accuracy of the electric drive control. Despite the standard solutions, such position master unit require improvement. In this regard, upgrading such a position master unit is relevant. The aim of upgrading is to eliminate these shortcomings by introducing corrective calculations and logical sequences that transfer the position master unit into a stable state as soon as it reaches a given value of the output coordinate. To control the motion of the electric drive when we develop a mathematical model and software based on it, it is necessary to use computational algorithms and numerical methods of calculation that are the least costly in terms of execution time. A modernized mathematical model of the S-shaped trajectory of position master unit is proposed. Restrictions of the parameters of this master unit have been eliminated. They may lead to incorrect path generation, as well as self-oscillations of the output and intermediate coordinates during the path generation, which reduces the accuracy of the electric drive control and cause vibration and noise. The software of the modernized position master unit, in comparison with its original form, does not contain cumbersome arithmetic that is costly in terms of execution time. The software has been successfully implemented into the microprocessor control system of the electric drive. At the same time, it is necessary to observe a time-stable execution of computational sequences and to consider the influence of the values of the numerical parameters used in the calculations.

Разработка программного обеспечения электропривода для группового управления в электромеханической системе

Background. To operate multi-coordinate electromechanical systems require control of electric drives coordinated in time and space along each of the axes, which is called coordinated control. Thus, various computing tools and mathematical algorithms are used. They establish the baseline of the software for microprocessor control systems. At the same time, the implementation of control algorithms is limited by the computing resources of the hardware parts of control systems, including the limitations of the tools of information transmission. To consider and eliminate these limitations and thus, to improve operation of the multi-coordinate electromechanical system, the aim of the article is to update control algorithms and balance distribution of computational resources of electric drives control systems. Materials and methods. Data are presented on the software development for coordinated control of several electric drives as a part of an electromechanical system that performs coordinated motion along its axes in time and space. To synchronize the control, the following technical solutions have been applied: description of the path of the high-level controller in the form of a sequence of reference points, buffering the coordinates when received by the electric drives and subsequent interpolation. Balanced distribution of resources between the high-level controller and local systems of electric drives is carried out considering the intensity of data exchange via the network interface. When calculating the reference points by the high-level controller, approximation of the paths by line segments at time intervals of variable duration is carried out to describe the generic path within the allowable mismatch. Results. The algorithm to synchronize the system time of the electric drives and the high-level controller has been implemented to synchronize the interpolation of paths. To implement this algorithm and transfer the coordinates of reference points to electric drives, special commands are used. They have different priority levels depending on the required speed of execution. In accordance with this algorithm, software has been developed as an element of the microprocessor control system of the electric drive. Conclusions. Application of various technical tools and computational algorithms that make it possible to allocate the computing resources of the control system and rationally use them contributes to efficiency improvement, in particular, the consistency and timeliness of electric drives control as a part of multi-axis electromechanical systems. The authors have proved the efficiency of the approach of coordinated control with the use of buffering coordinates of reference points followed by interpolation of the paths depending on the system time of each of the electric drives.

ЕКСПЕРИМЕНТАЛЬНІ ДОСЛІДЖЕННЯ КОНТРОЛЕРА ДЛЯ КЕРУВАННЯ ТЯГОВИМ ЕЛЕКРОДВИГУНОМ НА ПОСТІЙНИХ МАГНІТАХ

The controller of traction electric motors on permanent magnets for vehicles in which the power transistor converter is made on the modified IGBT modules with the improved characteristics is described in this work. The use of these modules, which are widely used today in semiconductor devices of modern dual-use technology, allows to reduce the size and weight of the converter, simplify the cooling system, increase efficiency and reliability of the semiconductor converter and electric drive in general due to harsh operating conditions. Bench tests of the experimental sample of the semiconductor converter and the microprocessor control system in various operating modes, including at the maximum load corresponding to real operating conditions are made and carried out. As a result of tests, it was determined that the technical characteristics of the controller meet the requirements of such devices. The created semiconductor controller on IGBT modified modules can be used to control motors on permanent magnets and motor wheels with a nominal power of 40-50 kW, maximum - 100 kW. References 11, figures 8, tables 4.

SYSTEM OF MECHATRONIC CONTROL MODULES FOR ADAPTIVE BRAKING

The purpose of the work is to increase the stability of the process of movement and braking, as well as to increase the wear resistance of the equipment of the locomotive and the rail track, by developing and improving adaptive systems that maintain optimal adhesion of the wheel to the working surface of the rail.
 The theoretical conclusions obtained and the results of model studies show the effectiveness of the proposed adaptive control method for adaptive systems and the possibility of building a simple microprocessor control system for the brake and sand feeding, supplementing the regular system of the locomotive, aimed at eliminating the loss of adhesion.

Analysis of Exchange Power in the Power System of Drone

The classification of drones - both military and civilian according to the relevant criteria - is presented. Block diagrams of a typical unmanned aerial vehicle and its power system are shown. Typically, a drone power system of the "micro", "mini" or "short range" category, according to the UVS international classification, is a set of DC / DC converters with a microprocessor control system. The power source for such aircraft is usually a battery, less often - fuel cells. During the flight, the engine speed is variable, and its change depends not only on changes in flight speed or direction, but also on weather conditions, such as wind, as the stabilization system constantly aligns the drone. This leads to the fact that the power supply system of such a device is actually a significant part of the time in transition condition. This leads to a significant content of the component of exchange energy that battery consumed which in turn will increase losses, and thus reduces the range of the unmanned aerial vehicle. The phenomenon of the occurrence of exchange power in the power supply systems of electric vehicles which powered from DC sources and specifically in the power supply system of an unmanned aerial vehicle is analyzed. The time diagrams of current, voltage, active and inactive components of power consumed from the mains power supply network of electric locomotive DE1 are illustrated. It can be seen that with a sharp change in the modes of operation of traction units there is a significant component of exchange power in the motor-network system. Such processes are typical for almost any electric vehicle and are associated with the presence of a significant number of reactive elements in the power supply systems, as well as frequent changes in load parameters. A block diagram of a typical unmanned aerial vehicle is presented. The unmanned aerial vehicle system consists of three parts: the air part, the unmanned aerial vehicle itself, the ground control station, which can be autonomous or manned, the control system, which provides communication and data transmission. The block diagram of the power system of a typical unmanned aerial vehicle is presented A simplified schematic diagram of the DC motor power supply system is presented. The relations for determining the amount of exchange power in the power supply system of an unmanned aerial vehicle are derived. It is concluded that to reduce the impact of this phenomenon, it is necessary to modify the power supply system by adding compensation units of inactive power component.

ПРЕЦИЗИОННАЯ ЛАБОРАТОРНАЯ ПЕЧЬ ДЛЯ ПОЛУЧЕНИЯ НАНОЧАСТИЦ С СИСТЕМОЙ ПРОГРАММНОГО УПРАВЛЕНИЯ И ОБЛАЧНЫМ МОНИТОРИНГОМ

Introduction: The development of a precision reaction furnace with a microprocessor control system based on an IoT class ESP-8266 microcontroller and a K-type thermocouple is presented. The temperature in the furnace hearth is maintained in the range from 50 to 350 °C with an accuracy of 1%. The temperature compensation of the cold junction of the thermocouple is provided. To improve the contro-accuracy and adjust the controller parameters, a reference mathematical model is used. Methods: a procedure for identifying the parameters of the reference model using the least squares has been developed. Regulator settings eliminate the occurrence of overshoot or fluctuations in the transient. A mode for monitoring the temperature and current power of the heater with visualization and logging of telemetry data to the cloud service (Telegram bot) has been implemented. Results: a mobile application implemented on a smart phone allows you to remotely receive temperature data and control the operating modes of the furnace. The duration of the experiment is actually not limited, the continuous operation of the furnace was tested on an interval of 24 hours. For high temperatures, in order to preserve the crucible, a mode of automatic stepwise heating and cooling is implemented. The furnace allows chemical reactions to be carried out at high temperatures in stabilization or program control modes, including decomposition reactions or the synthesis of nanoparticles from copper and other metals.

СИСТЕМА УПРАВЛЕНИЯ СИЛОВОЙ УСТАНОВКОЙ МАНЕВРОВОГО ТЕПЛОВОЗА С АЛГОРИТМОМ АВТОМАТИЧЕСКОГО РЕГУЛИРОВАНИЯ СКОРОСТИ

Work objective is to develop an algorithm for automatic speed regulation and to ensure its integration into the system of adaptive combined control of the power equipment of the locomotive TEM7A. Research methods: methods of the theory of automatic control, modern programming methods, trial trips. Research results and novelty. For the first time, the problem of automatic maintenance of "creeping" train speeds with high accuracy has been solved in the practice of domestic locomotive construction. It is established that the developed algorithm for automatic control of the humping speed and splitting up of shunting locomotive TEM7A allows maintaining a given speed in the range of operating speeds up to 8 km / h. Conclusion. The developed algorithm is integrated into the microprocessor control system of the power equipment of TEM7A shunting locomotive and does not require additional costs when through the locomotive operation. Maintaining a uniform speed of movement can also be used in the mode of manual control of the locomotive by the driver, while the value of the stipulated rate is set by the driver using the display module of the control panel.

DEVELOPMENT OF MICROPROCESSOR SYSTEMS CONTROL OF GAS ICE FOR OPERATION WITH LIQUEFIED PETROLEUM GAS

The expediency of converting the transport diesel engines in operation into gas internal combustion engines with spark ignition for operation on liquefied petroleum gas has been substantiated. It is shown that the use of liquefied petroleum gas instead of diesel fuel can reduce the operating costs of vehicles. Multifunctional electronic microprocessor control systems based on Avenir Gaz 37 level “A” and Avenir Gaz 37 level “B” electronic control units have been developed. It is shown that an electronic microprocessor control system with an Avenir Gaz 37 electronic control unit of level "A" allows converting diesel engines into gas internal combustion engines with LPG supply through a gas-air mixer into the intake manifold. The test results showed the high energy and efficient performance of the gas internal combustion engine. The second electronic microprocessor control system with an electronic control unit Avenir Gaz 37 of level "B" allows converting diesel engines into gas internal combustion engines with LPG injection through an accumulative power supply subsystem and multipoint injection of liquefied petroleum gas (Common Rail type) in combination with the use of a contactless electronic subsystem ignition with a movable voltage distributor and a cylinder filling control subsystem with a charge of the working mixture. At the same time, Avenir Gaz 37 "B" ECU with a loaded B1 level software module provides group injection of LPG into the intake manifold and sequential injection with a B2 level software module. The principle of operation of each of the three subsystems, which the D-240-LPG-"B" gas engine is equipped with, is described. The tests carried out on the D-240-LPG-"B" gas engine with the Avenir Gaz 37 "B" control unit confirmed its operability.