MODELLING AND SIMULATION OF DYNAMIC PROCESSES OF PNEUMATIC LINES

The paper presents the simulation of dynamic processes of pneumatic lines using the program "SIMULINK" from the product " MatLab". Simulation is a process of forming, preparing and entering a mathematical model in a computational environment and obtaining the results of the calculations performed in this environment. The mathematical model of the pneumatic line to be simulated is according to previously presented equations. For the simulation of the dynamic processes, various real parameters of the dimensions and lengths of the pneumatic lines with the corresponding coefficients are introduced into the model. The simulation of the transient responses was carried out with stepwise variation and sinusoidal input signal supplied by the set point device and pneumatic line lengths of 1 m, 5 m and 10 m. The simulation output data were output to the interface in the form of graphs showing the dependence of the observed quantities, the input and output pressure through the pneumatic line, and the input and output flow rates. From the mathematical model and the experiments performed, it can be concluded that the transient responses in the simulations correspond to the dynamic processes of pneumatic lines of different lengths

SIGN LANGUAGE OF THE DEAF PEOPLE: A STUDY ON PUBLIC UNDERSTANDING

Today, when various regulatory documents support sign language research, there is a lack of both teaching materials and research on deaf sign language and public understanding. The study aims to determine the public’s proficiency or competence in the Latvian sign language. The research revealed people’s basic knowledge of Latvian sign language grammar, their ability to communicate and understand deaf people, their attitudes and opinions about the process, and the necessity of learning sign language. Information was studied in four blocks of questions: society’s attitude towards deaf sign language, society’s knowledge of deaf sign language, communication skills with a deaf person, and opinion on the development of deaf sign language and its necessity. The sample of the study is 500 respondents, who represent the opinion of the population between the ages of 16 and 60, observing the socio-demographic parameters of the target group of the study. An empirical research method was used in the study; to collect data, an electronic survey was conducted. In general, the study confirms that society shows a positive attitude towards Latvian sign language as a means of communication for deaf people. At the same time, the data reveal poor knowledge of sign language and its grammar. It was concluded that not only sociological research is needed on public perceptions of deaf sign language, but also various educational events for the rest of society should be promoted, including seminars, courses, and conferences

ALGORITHM FOR OPTIMIZATION OF IDLE TOOL MOVES WHEN MILLING COMPLEX SURFACES ON A TRIAXIAL CNC MILLING MACHINE

The idle running times of the working units of a machine tool are the sum of the idle running times for the tool change and for changing the section uder treatment. The time, spent on idle running is the extra machining time. A large number of milling cutters are used for purely mechanical machining of details with complex surfaces and for a significant number of machined sections, where the complex surface is broken as a rule. This leads to an increase in the extra time for treatment. Reducing the auxiliary time in machining the parts will significantly increase the productivity of the actual milling process. When modeling the process of machining details with complex surfaces on triaxial milling machines, the optimization of the sequence of moves will allow to reduce the idle running time by up to 50% without causing deterioration in the quality of the surface layer

COMPARISON OF POTENTIAL ROAD ACCIDENT DETECTION ALGORITHMS FOR MODERN MACHINE VISION SYSTEM

Nowadays the robotics is relevant development industry. Robots are becoming more sophisticated, and this requires more sophisticated technologies. One of them is robot vision. This is needed for robots which communicate with the environment using vision instead of a batch of sensors. These data are utilized to analyze the situation at hand and develop a real-time action plan for the given scenario. This article explores the most suitable algorithm for detecting potential road accidents, specifically focusing on the scenario of turning left across one or more oncoming lanes. The selection of the optimal algorithm is based on a comparative analysis of evaluation and testing results, including metrics such as maximum frames per second for video processing during detection using robot’s hardware. The study categorises potential accidents into two classes: danger and not-danger. The Yolov7 and Detectron2 algorithms are compared, and the article aims to create simple models with the potential for future refinement. Also, this article provides conclusions and recommendations regarding the practical implementation of the proposed models and algorithm

INVESTIGATION OF THE INFLUENCE OF TECHNOLOGICAL PARAMETERS OF LASER MARKING ON THE DEGREE OF CONTRAST

In modern production, each finished product entering the market is identified by a special marking. Each mark must meet requirements such as good coding, easy to see, easy to read by certain readers, stable over time, etc. In the present casting, laser marking of the C75 steel was carried out with a fiber laser with an average power of P = 30 W and a wavelength of λ = 1064 nm. For semi-contrast marking, marking speeds from 100 mm/s to 700 mm/s, average power from 10 to 30 W, raster pitch from 20 µm to 60 µm, scanning frequency from 20 kHz to 150 kHz were investigated as constant parameters are the pulse duration τ =100 ns, number of repetitions N = 1 and defocus Δ f = 0 mm. The influence of the changing parameters on the contrast was established, and experimental dependences were constructed. The achieved research results show that to obtain a high contrast mark, the average power should be above 20 W, the scanning speed up to 300 mm/s, the scanning frequency up to 50 kHz and the raster pitch up to 40 µm

DEVELOPMENT OF A METHOD FOR CONTACTLESS TEMPERATURE MEASUREMENT IN 3 SPECTRAL RANGES

A 3-spectral method for non-contact temperature measurement has been developed. Three silicon photodiodes were used. The separation of the spectrum is done by optical bandpass filters and beamspliters. It is possible to work in three modes: three-spectral, two-spectral (spectral ratio) and one-spectral. In the first mode, the temperature of objects with an unknown and variable emissivity can be measured. The last two modes give good results respectively for gray bodies and for objects with known emissivity

MATHEMATICAL MODELING OF THE SEQUENCE OF MACHINING SECTIONS OF COMPLEX SURFACES WHEN MILLING ON A TRIAXIAL CNC MACHINE TOOL

The idle running times of the working units of a machine tool are the sum of the idle running times for the tool change and for changing the area uder treatment. The paper presents mathematical models, establishing the relationship between the additional time for performing the technological operations with the parameters of both the technological equipment and the object under treatment. The mathematical models for minimizing the idle moves when a tool passes from one machined section to another, allows to reduce the additional treatment time, which, in turn, leads to an increase in the productivity of the process of actual milling

APPLICATION OF A FINITE ELEMENT MODEL TO OBTAIN THE INFLUENCE OF THE TREATMENT’S POWER, REFLECION AND FOCAL DIAMETER IN LASER TEXTURING OF ALUMINUM

In this work, a numerical model of laser texturing is considered. A finite element model of a representative sample of pure aluminum was created. The impact of a laser pulse was simulated, assuming a Gaussian volume distribution of the heat flux. Material properties are assumed to be constant and latent heat is accounted for. Results are obtained for the thermal field and the width of the vaporized zone, assuming that the crater is characterized by its maximum width. The numerical model was used to study the influence of pulse power density, reflection, focal diameter and pulse duration. The ablation threshold at different laser pulse durations was determinate.

INVESTIGATION OF LASER MARKING AND TEXTURING OF TITANIUM GR 2 WITH FIBER LASER

Titanium Gr 2 is widely used in engineering and medicine due to its excellent mechanical and corrosion-resistant properties. Laser marking is a crucial process for many applications that require high-contrast, durable markings. In this study, we used a Rofin PowerLine F 20 Varia fiber laser to mark titanium Gr 2 with a 6x6 matrix of 5x5 mm squares. We varied the speed (100-1100 mm/s), power (8-18 W), and frequency (100 and 500 kHz) of the laser marking process to investigate their effects on the surface roughness and contrast of the markings. We analyzed the markings using a laser scanning microscope and Adobe Photoshop software. Our results show that the contrast and roughness of the markings were influenced by the frequency, scanning speed, and power. High marking speeds produced lighter markings, while low marking speeds produced darker markings. We also found that the surface roughness increased with higher frequency and powers. Our findings provide valuable insights into the optimal laser marking parameters for titanium Gr 2, which can enhance its performance and durability in various applications

INGREDIENTS DEGRADATION IN STEEL FIBER REINFORCED CONCRETE AFTER THERMAL LOADING

The steel fiber reinforced concrete in structures provides good mechanical and physical characteristics and such material applications are increasing. At the same time, if structure is subjected to thermal load it is affecting both properties of reinforcement and matrix as well. The aim of the present research is to investigate the degradation of the characteristics of fibers, randomly distributed in the body of concrete block. A short steel fiber reinforced concrete slabs (400x300x18cm) [1], [2] with homogeneously distributed fibers was undergone to calefaction process from one side. dimension of 16.5x14.5x15 cm) Fiber fracture process was performed based on the single fiber pull-out test by preparing the specimens with fiber from calefacted SFRC block. Experimental curves from each layer were compared with different layer of fibers and investigation had shown that higher load-bearing capacity is there over the thermal loaded fiber. The conclusion were made with the microscopic results and the experimental data