У роботі здійснено математичне моделювання, яке дозволило визначити раціональні параметри та режими роботи сенсору для забезпечення максимальної чутливості схеми. Досліджено параметри процесу контролю та межі застосування методу. Здійснено моделювання контролю дефектів різних типів.Здійснено моделювання розподілу чутливості ємнісного сенсора, що дозволило порівняти сенсори різної геометричної форми та визначити оптимальні конструктивні параметри. Запропоновано конструкцію сенсора, яка має найвищу чутливість та глибину проникнення. Здійснено моделювання процесу контролю матеріалів зі змінними провідними властивостями, що підтвердило можливість застосування методу для такого класу матеріалів.Розроблено спосіб підвищення завадостійкості та швидкодії методу. Проведено експериментальні дослідження, які підтвердили працездатність електроємнісного методу для контролю дефектів. Шляхом математичного моделювання проаналізовано вплив різних чинників на випадкову похибку вимірювання.^UThe dissertation is devoted to the solution of the scientific and technical task of improving the electric capacitance method of non-destructive testing of materials through the development of systems structures for increasing the sensor sensitivity and speed of the device. It is also devoted for studying the parameters and operating modes of the sensor to ensure the maximum sensitivity of the measuring scheme, the influence of the geometric shape and dimensions of the sensor on its sensitivity.In this work it was make an overview of the problem of electrical non-destructive testing in the manufacture of nanomodified intelligent polymer composite materials, taking into account the need for point measurement of dielectric material permeability and control of the depth of intelligent sensors introduction in the melt of polymer material in real time with the possibility of only one-way access to the object of control.The electric capacitance method is one of the most versatile and easy to use. Be this method it is possible to solve a significant range of research tasks. However, by this time, the electric capacitance method was used only for the integral evaluation of the parameters of the object of control. Using the method for point control is limited by a significant control time, which is due to the use of Wheatstone bridge schemes for measuring small capacitance values with high accuracy. This is explained by the fact that such schemes require multi-step algorithms, which leads to a significant increase in the measurement time. When scanning object of control in many points the time consuming becomes unacceptably large. Besides, for this method there are no analytical methods for finding capacitance of the asymmetric sensors and sensors of complex form requiring the use of computer methods for calculating capacitance. Also, the issue of combating electromagnetic interference is still unresolved.The theoretical substantiation of the electric capacitance method and object of control is carried out. The method of measurement and criteria for estimating the sensor operation is proposed. The recommendations for determining an optimal parameters of the work and minimum possible dimensions of the sensor for the implementation of the defectoscopy are obtained.The optimal frequencies are determined for the application of the method and a method for determining these frequencies when changing the parameters of the scheme is proposed. With the help of simulation, the dependence of the sensor capacity on the characteristic size of the electrode was determined, which allowed setting the minimum possible value of the electrode, which is may be measuring the change in capacitance, that was 6x6 mm.It was investigated the parameters of control process and the limits of method application for conducting and non-conducting samples, in particular: thickness of the control object, working gap, relative permittivity of the sample.Simulation of sensor parameters, namely the distribution of sensitivity, allowed to compare sensors of different geometric shapes and to determine the optimal design parameters for the sensitivity criterion. The design of the capacitive sensor is proposed, which ensures achievement of the highest sensitivity. The proposed sensor has a 50% greater control depth and 63% greater sensitivity than with standard sensors. Thus, the proposed sensor combines the advantages of previously studied sensors and is best for use in nondestructive testing.The method of increasing noise immunity is developed, which allows to register with high accuracy the change not only of the phase shift of the measuring signal, but also the change in the amplitude of the measuring signal, which provides an increase in the accuracy of the measurement. On the developed method were obtained the Ukrainian patents for the invention.Experimental studies have been carried out, which confirmed the efficiency of the method for solving defectoscopy problems. The measurement error of the amplitude and phase of the signal, which is acceptable for control, is calculated.The hardware error has been determined, and the simulation in the MATLAB software complex has been carried out in order to determine the random error when measuring the developed scheme.

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.11.13 – Прилади і методи контролю та визначення складу речовини – Національний технічний університет України «Київський політехнічний інститут імені Ігоря Сікорського», Київ, 2021.У дисертаційній роботі удосконалено вихрострумовий метод ідентифікації матеріалу металевих виробів шляхом динамічного методу отримання вихрострумових сигналів, і крім того, завдяки запропонованим та використаним методам його обробки: спектральним методом, методом лінійного передбачення та методом графічно-цифрових образів. Показано, що спектральний метод та метод графічно-цифрових образів, що використовують узагальнений образ об'єкту контролю, дозволяють ідентифікувати метали в середині підгруп чорних та кольорових металів, а метод лінійного передбачення дозволяє лише ідентифікувати метали як чорний чи кольоровий. Аналіз ефективності алгоритмів обробки сигналів проведений шляхом моделювання на ЕОМ та експериментальних досліджень металевих об'єктів за допомогою розробленого діючого макета вихрострумової системи динамічного контролю показав вірну ідентифікацію металів.Ключові слова: ідентифікація металів, динамічна вихрострумова система контролю, спектральний метод, метод лінійного передбачення, метод графічно-цифрових образів.^UThesis for the degree of candidate of technical sciences in specialty 05.11.13 – Devices and methods of control and determination of substance composition – National Technical University of Ukraine " Igor Sikorsky Kyiv Polytechnic Institute", Kyiv, 2021.Today, in various fields of science, technology, inspection and military affairs, there is a need to detect and identify metal objects. This is related to the search for explosive metal objects, communications, identification of the metal from which the unknown object is made, identification of found nuggets, including hidden ones. To search, use electronic devices (metal detectors), built on the registration of differences in electrical and magnetic properties of hidden objects and the environment in which they are located. Such devices, in addition to searching, carry out preliminary identification of the metal. They determine which subgroup the metal belongs to - ferrous or non-ferrous metals. Metal detectors, which are an eddy current system for detecting metal objects, perform dichotomous analysis of metals, divide them into two large subgroups (black, colored) and do not provide the ability to identify metal within subgroups, but can not distinguish gold from aluminum or copper, nickel from steel etc.Final identification is performed by laboratory analysis of the composition of a metal object, which uses chemical, X-ray fluorescence or opto-emission methods. They require a metal sample and do not allow it to be identified remotely (contactless). In addition, the surface of the analyzed object must be cleaned of contaminants. For these reasons, laboratory analysis is not always acceptable. In cases where it is not necessary to establish the chemical composition of the metal object, but only to identify the metal from which the object is made, other methods can be used. One such method, after some refinement, may be the eddy current method of detecting metal objects, which belongs to the electromagnetic methods of detecting metals in a dielectric medium.In modern systems, the task of detecting and identifying metal objects rests entirely with the operator. This requires consideration of the human factor and leads to significant subjective errors in the identification of the material of the detected object. The identification of composition of the metal, a developed specialized digital electronic system is proposed, which performs dynamic recording of the eddy current control signal.The developed system uses the general principles of operation of a typical eddy current device - a metal detector, which are modified for dynamic removal of the eddy current control signal. The research uses metal objects of different shapes, which are commensurate with the "antenna" of the system (minimum sample 10x10x1 mm and maximum 80x80x5 mm) and only for this range of sizes the results of the dissertation research are correct!The reflected signal (response) of the eddy current control, which arises as a result of the interaction of the emitted signal with the metal object, carries information that depends on the electrical and magnetic properties of the metal. Each metal has a special physical nature and creates a specific reflected signal. The reflected signal is not an absolute characteristic of a particular metal and depends on a number of technical factors that require normalization of the trajectory of the "antenna" relative to the object or vice versa - the movement of the object relative to the "antenna". Therefore, in the designed experimental system, the reflected signal is its relative characteristic, which becomes absolute only after comparing different metals and creating their base. Thus, the task of developing methods and means of eddy current control, including their algorithmic and software, which are able to ensure the identification of objects made of metal with high probability.The eddy-current method is improved in the dissertation for identification of materials from metals by a dynamic method of receiving eddy-current signals, which is based and used next methods of processing: a spectral method, a method of linear prediction and a method of graphical - digital images.It is shown that the spectral method and the method of graphic-digital images, which use a generalized image of the object of control, allow to identify metals in the middle of subgroups of ferrous and nonferrous metals, and the method of linear prediction allows to identify metals as ferrous or nonferrous. The analysis of the efficiency of signal processing algorithms carried out by computer simulation and experimental studies of metal objects using the developed working model of the eddy current system of dynamic control showed the correct identification of metals.Key words: identification of metals, analysis of metals, eddy current control system, spectral method, linear prediction method, method of graphical and digital images.