Electromechanical Part Research Articles

Structure of software and hardware module for research of DC electrical machines. Part 1

The structure of a hardware and software complex for the study of DC electric machines and a mathematical model of its electromechanical part taking into account the influence of temperature on the resistance of the armature winding have been developed. The hardware and software complex is implemented on the Arduino Uno board. A distinctive feature of which is the modular structure, which allows conducting research on DC electric machines in various operating modes (start-up, armature speed control, reversing, braking). In addition, it is possible to implement various laws of changing the load moment. For this purpose, the hardware and software module include the studied and load DC electric machines, which are mechanically connected to each other by means of a coupling and operate in motor and generator modes, respectively. The proposed model makes it possible to describe electromagnetic processes in DC electric machines taking into account the influence of temperature on the resistance of the armature winding, as well as overheating of individual parts of the electric machine. The proposed hardware and software module can find practical application in research laboratories in the study of DC electric machines in various operating modes.

EFFICIENT USE OF ELECTRIC ENERGY WHEN OPERATING A BALL MILL WITH A CONSTANT ROTATION SPEED

Link for citation: Zakamaldin A.A., Perevoshchikov F.V., Shilin A.A. Efficient use of electric energy when operating a ball mill with a constant rotation speed. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 9, рр. 115-127. In Rus. The relevance. Ball mills are widely used in industry for grinding bulk materials, as well as in the last stages of ore crushing, where the required optimal particle sizes are achieved for enrichment. Although ball mills have a relatively simple design and cover extensive research, the industry is still struggling with the very low energy efficiency of the grinding process. As the retrofitting heavy equipment is the costliest approach, process optimization through control system is the most suitable for energy consumption reduction. As a rule, the feed rate is the main control variable for a mill with a constant rotation speed. Due to insufficient information content, outdated methods of analysis and control of the internal dynamics of the mill, control systems keep the target value of feed rate at a deliberately low level in order not to overload the mill. This article provides an explanation of how, in such a case, an increase in mill feed rate could affect the energy efficiency of grinding. The main aim: study of energy efficient modes of operation of stations; verification of models and confirmation of experimental data: the relationship between door loading and power consumption indicators; construction of buildings for energy efficient control of ball towers. Objects: the process of grinding in a ball tower with a constant rotation speed. Methods: mathematical description of the behavior of the electromechanical part of a machine that consumes current and works on a load in the form of spherical furniture; simulation modeling of the operation of the door electric drive; statistical analysis of production indicators. Results. The paper demonstrate the tendency to increase electricity consumption with a decrease in feed rate and vice versa, respectively for ball mills with a synchronous drive of 2500 kW based on modeling and experimental data. Increase in feed rate in the range of 10–40 t/h, there is a drop in active power by 0,48–1,57 %. The values of the specific power consumption of ~5–8 kWh/t during the grinding of apatite ore were obtained. An increase in productivity by 5 t/h on average leads to a decrease in the specific power consumption by 0,12 kWh/t. It is necessary to increase productivity in the operation of ball mills only after integrating measuring instruments into the control system of the mill, which allow an accurate assessment of the state of loading of the mill drum.

RESEARCH OF THE PRINCIPAL MODEL OF THE ELECTRIC ENERGY GENERATOR OF THE ELECTRIC CAR (STAGE COMBINATION OF MECHANICAL AND ELECTROMECHANICAL PARTS)

The article presents the interim results of the ongoing study (http://journals.ru.lv/index.php/SIE/article/view/6884/5683). At this stage, measurements are made with a model in which we combined the mechanical part with the electromechanical part. At the presentation stage, a model demonstrating the principle operation scheme of the patented device has already been constructed as an object of research. A rotating magnet was connected to the impeller (it was rotated by the impeller). The magnet was rotating around the stationary coils and was already inducing an electric current in the coils. In this way, the generated current and generated voltage values can be used as an indicator for evaluating the efficiency of the impeller. The experiments in question are performed with three impellers of different configurations, keeping other conditions analogous. All experiments were performed using only one rotating magnetic ring and one set of stationary coils. The results of experimental measurements show a wide spectrum and possibilities of increasing efficiency and demonstrate the principle of operation of the future device. When designing an impeller with turned wings, two cavities for magnets and coils are already provided, thus preparing for the next step in improving the design of the model under study and increasing efficiency.

ON THE PRINCIPLES OF CONTROL OF THE PROCESS PART OF THE AIRBORNE CLASSIFIER DURING OPERATIONS OF SPECIAL-PURPOSE ABRASIVE MATERIALS

The article considers the methodical methods of practical use of a vibrodynamic classifier for sieving various abrasive materials, sets and solves the task of providing optimal tuning parameters of the electromechanical part of the vibration classifier to obtain the highest grade of abrasive grain with a high content of the main fraction and a given shape of abrasive particles. The distribution of particles of the material separated by size along the perimeter of the vibration rod was studied, depending on its parameters. It has been shown that the yield of products depends on the ratio of fractions in the starting material.

A study of electrothermomechanical converter for technological purposes with nonlinear changes in the loading and cooling medium

Heavy temperature processes with high-temperature loads require optimisation of technological processes, ensuring high reliability and combining rotating parts of electric machines with actuators to achieve greater efficiency of electromechanical converters. The research aims to provide a theoretical justification and experimental confirmation of the effect of higher harmonics in the air gap under nonlinear changes in the temperature of the medium. The research is based on the basic principles of electrodynamics, heat and mass transfer, mathematical modelling by the finite element method, and experimental verification of multi-physical parameters. Based on the analysis of the differential equation for determining the increase in the surface temperature of a ferromagnetic rotor under conditions of nonlinear temperature changes in the environment surrounding the electromechanical converter, the regularities of the formation of the free and forced components of the instantaneous temperature values of the massive rotor are established. Depending on the mode of interaction between the load-cooling medium and the electromechanical part of the screw units, kinematic diagrams of single-mass and two-mass systems with variable or constant moments of inertia and stiffness were formed. According to the size of the electromagnetic system of the experimental sample, a mathematical model for studying thermal and electromagnetic processes was built. The regularities of the spatial distribution of the temperature of the screw electromechanical unit are determined. The spectra of higher harmonics of voltage and current in the frequency range from 0 to 50 kHz have been experimentally determined, which confirms the presence of the effect of generating higher harmonics when the temperature of the medium surrounding the rotor screw changes. The detected harmonic spectrum affects both the formation of the dynamics of the rotating system and additional thermal power while increasing the overall efficiency of the screw electromechanical converter. The practical value of the obtained results lies in the possibility of predicting the optimal indicators of interrelated electromagnetic and heat exchange processes in screw electromechanical converters for technological purposes

Snap-through triboelectric nanogenerator with magnetic coupling buckled bistable mechanism for harvesting rotational energy

We propose a snap-through triboelectric nanogenerator with magnetic coupling and buckled bistable mechanism to harvest rotational energy (ST-RTENG). The buckled bistable beam generates convex and concave snap-through under magnetic excitation, which can significantly increase the contact force of the functional materials of triboelectric nanogenerator (TENG), thereby significantly improving the electrical output. By adopting a magnetic coupling non-contact energy transfer mechanism, the drive part and the electromechanical conversion part are easily physically separated, which improves the robustness of the system in the harsh environment. The electromechanical coupling dynamic model of the system is established and verified by experiments. The different modes and key parameters of the magnet arrangement are investigated. The ST-RTENG with two pairs of magnets with staggered poles has a maximum voltage of 1235 V at a rotating speed of 150 r/min and a maximum average power of 778 μW at a rotating speed of 800 r/min. The prototype can light up more than 1000 LEDs under low speed excitation, and realize self-powered temperature monitoring and wireless transmission. The rotational energy harvester with magnetic coupling buckled bistable mechanism proposed in this paper can be used for wind energy harvesting in the field environment, self-powered state monitoring of the pressure pipelines, and other applications that require isolation of external excitation and electromechanical conversion components.

Technology for controlling access to the room via Web-application on the Internet

The article proposes a technology for controlling access through a Web application. In the first part, the implementation of the electromechanical part of the ACS, the key feature of which is the preservation of the last state when the power is turned off and the presence of an anti-panic mode. This feature is obtained by installing a geared motor on the lock cylinder. This solution allows you to abandon the need for certification of the lock, use both electronic control, for example, by means of a telephone or proximity cards, and classical control using a regular standard key, as well as finding the lock in any state for an arbitrarily long time, regardless of the presence of power. In the second part, the implementation of network interaction between the user and the directly controlled object is proposed.

Датчики тиску на основі ниткоподібних кристалів кремнію для зниження шумових параметрів автоглушників

The article contains the results of research and development of a system for active noise damping of an automobile engine. The main source of noise from a running engine is exhaust noise. The frequency spectrum of this sound has a pronounced low-frequency character, which explains its weak absorption when the sound is propagating in open spaces. A possible solution to this problem is to use an active system for suppressing the resonant frequencies of the muffler using strain gauges to read the primary information about the dynamic processes that determine the noise level. It is for such active noise suppression systems that the authors develop a high-temperature pressure sensor based on strain gauges made of silicon whiskers. Such strain gauges have unique mechanical properties, are characterized by high sensitivity and the ability to operate in various amplitude-frequency and temperature ranges up to 500℃. The study of the dynamic characteristics of pressure sensors made it possible to confirm the quality of its electromechanical part and determine that the measurement error of the sensor is ±0.5 in the temperature range of 20 to 500℃. The active noise suppression system is a buffer tank whose volume changes in accordance with signals from pressure sensors. This design makes it possible to dynamically change the resonant frequency of the buffer capacitance depending on the operating modes of the engine, which leads to a decrease in its noise characteristics. Using the developed additional resonator chamber with a variable volume in the exhaust muffler of an internal combustion engine made it possible to reduce resonance phenomena in the zone of low-frequency pulsations of the exhaust gas pressure from 57 to 43 Hz with a frequency drift in the range of 310 to 350 Hz, which significantly improved its noise characteristics.

Biomass Pyrolysis Using a Multifunctional Electromechanical Converter and a Magnetic Field

Abstract The wood waste conversion processes in a dry distillation chamber with an executive body based on a multifunctional electromechanical converter were analysed. It was established that under the influence of a low-frequency magnetic field, the properties of moisture evaporating from biomass change, and the evaporation heat decreases. A method for generating negatively charged molecular complexes in the form of water vapour by heating biomass, exposure to the electric and magnetic field, followed by the injection of negatively charged hydroxide ions of water vapour into a solid carbon product at the final stage of the pyrolysis process is proposed. The possibilities of heat recovery of the screw energy technological complex for preheating biomass in a loading device using the thermal energy of the spent heat carrier, the energy dissipative component of the installation’s electromechanical part and the thermal energy utilisation of the produced solid products have been estimated.

Застосування чисельних методів для реалізації системи позиціонування мобільного робота

Any modern production cannot be imagined without robotized processing lines of materials and assembly lines in such fields of production as, for example, aircraft and engineering, the manufacture of radio equipment, or in processes involving the use of caustic and toxic substances. Therefore, the promising scientific and technical direction is the development and improvement of the electromechanical part of production lines and complexes. The solution of this problem is possible due to the use of modern methods for collecting information from primary sensors, as well as the introduction of modern means of their processing and synthesis of control pulses on the electro-mechanical parts of the equipment. The precision of positioning of electromechanical elements of robotic technological manipulators directly depends on the accuracy of determining their position and following the rotor programmed trajectory. Therefore, it was proposed to use a phase method for measuring the displacement of the robot manipulator, which allows obtaining high sensitivity of measurement and, accordingly, ensuring a high degree of accuracy of operations and reacting to changes in production technology. The implementation of the phase measurement method is related to the use of the reference signal, according to which observation is carried out. However, in practice measurement occurs nonlinear effects of the medium of propagation of signals (nonlinearity immital properties of the medium, interference, etc.), which leads to a non-matching of the spectral composition of the measuring and reference signals. Another aspect affecting the measurement result is the accuracy of the approximation of the sensor transformation function based on the assumption that the measuring signal is quasigarmonic, which is not always true. Therefore, in this paper a numerical method for measuring the phase of continuous signals without binding to their geometric form is proposed.

Diagnostic and Monitoring System for Technical Condition of Electromechanical Section of Thermal Control Systems in Spacecraft

Modern diagnostics methods ensuring the safety of production and operation, as well as the improvement of functional characteristics of electromechanical systems’ are discussed, method of diagnostics according to the spectrum and hodograph of the engine’s equivalent current is presented. Functional concept is presented for the system of control, diagnostic and monitoring of technical condition of thermal control systems’ electromechanical part in the spacecraft. The decision-making and forecasting algorithm for the operational resource is based on ground-based studies and diagnostic results. This approach to device diagnostics and monitoring is also used in other servo drives, mechatronic and robotic systems of space vehicles and other objects that are inaccessible and left unattended. Hardware-algorithmic implementation of the system is described, recommendations on the components base selection are given.

Определение наработки и остаточного срока службы шахтных самоходных вагонов калийных рудников на основании данных комплексного контроля

Statistical data on the reliability of self-propelled mine cars (SPMC), operating in the potassium mines of the Verkhnekamskoye potassium and magnesium salts deposit are analyzed. Identified the main nodes that limit the resource SPMC. It has been proven that the most common failures of self-propelled cars are the failure of wheel hubs, bevel gears and traveling electric motors. The analysis of the system of maintenance and repair of mine self-propelled cars. It is indicated that the planning and preventive system of SPMC repairs is characterized by low efficiency and high material costs: car maintenance is often carried out upon the occurrence of a failure, which leads to prolonged downtime not only of a specific haul truck, but of the entire mining complex. A method for assessing the technical condition of the electromechanical part of a mine self-propelled car by the nature of power consumption is proposed. This method allows you to control the loading of the drives of the mine self-propelled car, as well as to assess the technical condition of the drives of the delivery machines in real time.Upon expiration of the standard service life of a mine propelled car specified in the operational documentation, its further operation is prohibited and the car is subject to industrial safety expertise. As part of the examination, it is necessary to determine the operating time and calculate the service life of a mine self-propelled car outside the regulatory period. A method has been developed for determining the residual service life of mine car on the basis of instrumentation control data in the conditions of potash mines.

Mechatronic treadmill for gait reeducation with control algorithm of treadmill speed adaptation

Different types of devices, from the simplest (medical walkers) to the most technologically advanced ones (mechatronic devices), are widely used to support the rehabilitation process for people who suffered strokes or have other disabilities—especially to enhance their mobility. This article presents a new mechatronic system for gait reeducation, which consists of two main components: training treadmill and body weight support system. The device is also equipped with sensors for measuring the rope inclination angle, rope tension and foot pressure on the ground. The transmission of measurement and control signals between the computer with control system and the electromechanical part of the device is realized by means of three real-time boards. This publication covers certain issues related to the device design process, integration of the main components, as well as the description of the developed treadmill speed adaptation algorithm and experimental verification of such control system. The speed of treadmill belt is adjusted by a feedback loop with a rope inclination angle measurement. Because of the kind of the connection of the treadmill (the control signals are sent to the buttons in the treadmill control panel) and related limitations, a proper conversion of the control signal was required, from a continuous one to a digital square wave signal with variable period. Developing an optimal treadmill speed control algorithm in this case was an interesting engineering challenge.

Evaluation of pull production control strategies under uncertainty: An integrated fuzzy AHP-TOPSIS approach

Purpose: Just-In-Time (JIT) production has continuously been considered by industrial practitioners and researchers as a leading strategy for the yet popular Lean production. Pull Production Control Policies (PPCPs) are the major enablers of JIT that locally control the level of inventory by authorizing the production in each station. Aiming to improve the PPCPs, three authorization mechanisms: Kanban, constant-work-in-process (ConWIP), and a hybrid system, are evaluated by considering uncertainty.Design/methodology/approach: Multi-Criteria Decision Making (MCDM) methods are successful in evaluating alternatives with respect to several objectives. The proposed approach of this study applies the fuzzy set theory together with an integrated Analytical Hierarchy Process (AHP) and a Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) method.Findings: The study finds that hybrid Kanban-ConWIP pull production control policies have a better performance in controlling the studied multi-layer multi-stage manufacturing and assembly system.Practical implications: To examine the approach a real case from automobile electro mechanical part production industry is studied. The production system consists of multiple levels of manufacturing, feeding a multi-stage assembly line with stochastic processing times to satisfy the changing demand.Originality/value: This study proposes the integrated Kanban-ConWIP hybrid pull control policies and implements several alternatives on a multi-stage and multi-layer manufacturing and assembly production system. An integrated Fuzzy AHP TOPSIS method is developed to evaluate the alternatives with respect to several JIT criteria.

Compensation for the Residual Error of the Voltage Drive of the Charge Control of a Piezoelectric Actuator

One very effective approach to suppress hysteresis from the piezoelectric actuator is to use the charge control across the associated capacitance. The charge driver often uses an additional capacitor connected to the piezo-actuator in series for the charge sense feedback control. When this charge sense is used with a voltage drive for the charge control, the applied voltage will include two parts. The one is the voltage drop across the useful electro-mechanical part and effectively converted to the driving force, whereas the other part indicates the equivalent voltage drop due to the hysteresis. In our research, we noticed that it is possible to use a simple estimator as the hysteresis voltage observer and use it to precompensate for the voltage drop. Comparing to the conventional hysteresis suppression achieved by the closed-loop positional control, we show significant improvement of the control performance. For dynamic applications, we also proposed a combination of the Preisach model with the hysteresis estimator to better suppress the nonlinear behavior. A series of experiments were conducted to demonstrate the performance improvement of the proposed compensator. A 10 nm and 25 nm maximum tracking error can be maintained while tracking a staircase reference and a 30 Hz sinusoidal signal, respectively.

Development of specialized modeling complex to study control systems of movable maritime objects

We designed, created, and tested a specialized modeling complex for examining and assessment of effectiveness of control systems for electric drives of direct and alternating current, which includes software and electromechanical parts. The latter is a metrologically certified training-research set-up Testing Stand SV-1, that allows conducting experimental studies with required accuracy. We presented characteristics and capabilites of electromechanical part of the modeling complex. The possibility is demonstrated to synthesize control systems for a propulsion device with barounloaded induction motor at rectilinear motion of underwater vehicle with different types of regulators and their subsequent correction by means of the specialized modeling complex. Experimental studies conducted on the specialized modeling complex of control system confirmed effectiveness of the received laws of control during motion of underwater vehicle under arbitrary law of change in its horizontal rectilinear speed, the discrepancy between results of computer simulation and experimental research is 5–8 %. The results we obtained are implemented in teaching process, and are used to solve relevant scientific, research and military tasks.

Robot-Server Architecture for Optimizing Solar Panel Power Output

Solar panel facilities for generating electricity have increased exponentially in the recent years. Dust and bird droppings on the solar panels inhibit the energy production. Having people to inspect them and, if needed, clean them is expensive and increases the energy cost. In this research paper we introduce a robot-server architecture for the purpose of inspecting the panels and cleaning them if there is a need for it. The general architecture of the robot consists of a mechanical part, an electromechanical part, an electronic part, and a software part. The mechanical and electromechanical parts consist of an all-terrain vehicle, two electric brushless motors, a telescopic vision system, and telescopic cleaning system with a brush, stepper motors controlling the telescopic vision system, and the telescopic vacuum system with a brushless electric motor. The electronic system consists of three electronic speed controllers, navigation sensors, a computer board, a hard disk, a transceiver, and an antenna for wireless communication. The software consists of a scalable operating system, an intelligent vision system with pattern recognition, a communication software system, an intelligent navigation system, and a file server with a database, TLS security, network communication software based on UDP, and internet communication based on websockets and TCP-IP. In addition to that for street solar lights we designed a PCB board with a sensor that activates a mechanism similar to windshield wipers that cleans the glass of the solar panels powering the lights automatically when needed.

A system of online diagnostics of the technical condition of wind power plants

The main issues of monitoring the technical condition of the electromechanical part of wind power plants in accordance with the concept of SMART GRID local networks are discussed. The creation of an integrated system of online diagnostics of the technical condition of wind power plants for autonomous energy sources is proposed. A mathematical approach to diagnostics of the technical condition of the electromechanical part permitting one to combine monitoring capability and control in a single facility is developed.

Synthesis of an Object Moving Control System with Flexible Suspension under the Action of External Forces

The paper presents electromechanical systems with flexible linkage, which movement parameters shall be specified by external force impact. The approaches to the compound movement division of such systems into components are given. The requirements to the control system of object horizontal moving with flexible suspension are formulated. The block diagram of electromechanical part of object horizontal moving system to research the impact of disturbing effect on its work is presented. The feasibility of using grapho-analytical methods and inverse frequency characteristics of control system synthesis is proved. The structure of corrective device is defined and a guideline for its parameters for its selection is given. The results of control system operation simulation with the synthesized corrective device are described. The recommendations for using adaptive control of object horizontal movement systems with flexible suspension are given. The results of system operation are compared with the recommended rational parameters of the corrective device and with application of adaptive control.

The peculiarities of the wind power generating autonomous system exploitation in the underground mountain iron-ore mining

The possibility and specifics of wind power complex functioning in operating underground iron-ore mining were analyzed. Aerodynamic features of ventilation airflows in underground iron-ore mining and their impact on the wind power plant operation were investigated. The design of wind power plant was substantiated and proposed for the practical implementation to realize its optimum possible efficiency. The structure of electromechanical part of the wind power complex and the control system for it with a predicted reliability and quality capacity of power supply to consumers of underground iron-ore mining electric power were developed. The behavior was investigated, and the control law was developed for the regulator of capacitive excitation current of induction generator of wind electromechanical complex with direct wind power conversion into electric power that provides energy-efficient operation modes of wind power plant electromechanical complex. The economic efficiency of using wind power plant in underground iron-ore mining was proved.