Journal of Mechanical Engineering, Automation and Control Systems
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Exciters of vibrations with two pairs of impacting surfaces
Get PDFExciters of vibrations of the type when one vibrating mass performs impacts into two immovable supports, which are located on the opposite sides with respect to the mass, are investigated. Here because of the connection of the vibrating mass with the supports the system may have the point of equilibrium located at equal or different distances from the impacting surfaces. Also, because of the difference of coefficients of restitution of impacts the system may have symmetric or non-symmetric laws of motions of the vibrating mass. Such systems are important in pipe robots and other engineering devices. Typical results of investigation of dynamics of such systems are obtained. The presented results can be used in the process of design of systems with vibrators having two impacting pairs. Investigations are performed by using analytical as well as numerical methods (calculations are performed by C++ Builder Community Edition, Newmark constant average acceleration method is used for numerical integration of equations of motion). The obtained typical graphical relationships show symmetric as well as unsymmetric regimes of motion and enable to perform their comparison. The basic novelty of this paper is the investigation of unsymmetric regimes of motion
Case report – distoclusion treated with Bimler A períod of 12 months
Get PDFThe Bimler type A utilizes forces derived from muscles, particularly the tongue, concomitantly, it acts as a systemic, dynamic and functional treatment, Bimler appliances transmit neural excitation throughout the system. The objective of this study was to present a clinical case and demonstrate the efficacy of the functional orthopedic appliance, specifically the Bimler A elastic modeler, in the treatment of a patient diagnosed with distoclusion (prognathism of the maxilla and retrognathism of the mandible) according to Bimler and McNamara cephalometry. The case involved a 9-year and 11-month-old male patient with atypical swallowing, respiratory issues, and allergic conditions such as asthma. Clinical examination and complementary tests revealed a large overjet, a narrow maxilla and mandible, an open bite, and distoclusion (retrognathism). The proposed intervention included the installation of the Bimler Elastic Modeler (BEM), type A. The treatment duration was 12 months, with ongoing monitoring every 2 or 3 months. The comprehensive approach, combining BEM type A, chewing exercises, and occlusal adjustments, resulted in orthopedic changes improved mandibular, tongue, lip, and head posture, as well as enhanced chewing balance. Importantly, the appliance effectively repositioned the mandible into a more balanced, normoccluded position without the need for elastic or constant forces. Beyond the orthodontic changes, the active engagement of facial expression muscles during these activities contributed to an overall improvement in facial harmony, achieving lip seal and notable enhancements in breathing. These positive changes extended to the patient’s daily activities and sports performance. The observed outcomes not only increased the child’s active participation in the treatment but also positively impacted self-esteem, driven by the aesthetic, functional, and psychological improvements experienced
Exploring CO2 storage potential in Lithuanian deep saline aquifers using digital rock volumes: a machine learning guided approach
No full textThe increasing significance of carbon capture, utilization and storage (CCUS) as a climate mitigation strategy has underscored the importance of accurately evaluating subsurface reservoirs for CO2 sequestration [1]. In this context, digital rock volumes, obtained through advanced imaging techniques such as micro-Xray computed tomography (MXCT), offer intricate insights into the porous and permeable structures of geological formations [2]. This study presents a comprehensive methodology for assessing CO2 storage viability within Lithuanian deep saline aquifers, namely Syderiai and Vaskai, by utilizing petrophysical properties estimated from digital rock volumes [3, 4]. These petrophysical properties were derived from core samples collected from these formations. Utilizing machine learning algorithms, porosity was estimated while the Lattice Boltzmann method (LBM) was applied to determine permeability [5]. The methodology employed for estimating these petrophysical parameters was initially validated using samples from formations analogous to Lithuanian formations. Subsequently, it was applied to rock samples specifically obtained from Lithuanian formations. The estimated petrophysical properties were compared with peer-reviewed data from published literature. When fluids such as CO2 or H2 are injected into sub-surface reservoirs, they can alter pore and grain characteristics. Therefore, it is crucial to extract representative element volumes (REVs) from segmented volumes to study the impact of fluids on porosity and their distribution [6]. These mini models, representing small portions of the larger formation, assist in predicting fluid flow within the formation, which is vital for assessing the efficiency and safety of carbon capture and storage (CCS) operations. Subsequently, numerical modelling was conducted using the petrophysical parameters as inputs to assess the storage capacity of the Lithuanian formations using tNavigator software [7]. This research contributes to an enhanced understanding of pore space distribution and its role in various aspects of long-term CO2 storage. It also demonstrates the potential of integrating advanced imaging techniques, machine learning, and numerical modeling for accurate assessment and effective management of subsurface CO2 storage. This study shall aid in enhanced understanding of pore space distribution and their contribution towards various aspects of long-term storage. The results can be extended to study the geochemical reactions and geo-mechanical behaviour of the rocks. Such studies shall further facilitate identification of reservoir(s) wherein sequestration potential can be reliably explored
Influence of wheelset structural flexibility on dynamic properties of a wide-gauge six-axle heavy-haul locomotive
Get PDFWheelset structural flexibility, that is the elastic deformation of the wheelset as a structure, has an important influence on the dynamic properties of railway locomotive vehicles at medium and high frequencies. Based on the practical structural parameters, this paper proposes a multi-degree of freedom rigid-flexible coupling dynamic model of a wide-gauge freight electric locomotive with C0-C0 bogies with an axle suspension driving system. The wheelset with the interference-fit large gear is made flexible using the finite element method, and then the rigid-flexible coupling vehicle model with elastic wheelsets is established in the software SIMPACK 2020. A short-wave irregularity superposed on the American fifth-grade track irregularity is used as the track excitation to study the performance at higher frequencies. From the modal analysis of the vehicle, it is obtained that the lowest frequency at which the elastic deformation of the wheelset occurs is 24.631 Hz. The lateral vibration responses of the vehicle with elastic wheelsets are reduced mainly in the frequency range of 30-150 Hz. There are two resonances in the lateral vibration responses at the mode frequencies of the vehicle over 50 Hz, which are close to the wheelset’s first mode frequency. Taking the ГОСТ standard of wide-gauge countries as the main reference, simulations are separately taken in straight-line and curved-line cases. Results show that the wheelset structural flexibility mainly influences the vehicle lateral stability and safety
The application of fault diagnosis techniques and monitoring methods in building electrical systems – based on ELM algorithm
Get PDFThe reliability of modern building electrical systems are receiving increasing attention as they become more intelligent and complex. As the majority of building electrical systems use neutral point grounding, earth faults or short circuits can get worse over time and damage both the distribution system and the electrical equipment. To this end, the corresponding three phases and four categories, namely three-phase voltage, three-phase current after fault, three-phase voltage distortion rate, three-phase current distortion rate, a total of 12 dimensional fault feature vectors and 10 fault simulation types, were summarised and extracted in conjunction with the actual operating conditions of the system. Using traditional fault identification ideas and neural network algorithm as reference, a 12-dimensional fault feature vector is used as the model input to construct a building electrical fault diagnosis and detection model based on ELM algorithm. Results showed that the ELM-based model’s classification accuracy for this experimental sample was 97.56 %, its AUC was 0.92, and its RMSE was 0.3521. These figures were higher than the classification accuracy and performance of the BP algorithm and GA-BP algorithm fault diagnosis models, and they also demonstrate better robustness and generalizability. The model also has a 97.27 % correct rate in fault discrimination, while the computation time is only 0.201 s, and its fault identification and diagnosis speed is faster than other algorithmic models. At the same time, this research model has a good fault monitoring accuracy of up to 98.6 % for building electrical systems. The research can provide a more sensitive, accurate and rapid fault monitoring method for the current building electrical system. It also improves the reliability of the building electrical system in a complex environment and achieves better protection of the system. This has a certain significance for the development of the building electrical industry
A review on path planning ai techniques for mobile robots
Get PDFAn Industrial Robot is used in industries for transporting, assembly, manufacturing and many more applications. Industrial robots include manufacturing robots, material handling robots, robotic arm and manipulator, mobile robots, assembly robots, etc. In this paper, Mobile Robots are further being discussed. One of the tools that a Mobile Robot uses to function is all with the help of Artificial Intelligence (AI) for performing several tasks autonomously. AI works as the intelligence of the human body for robots. AI is the technology that made it possible for robots to be capable of being totally autonomous. AI marks its presence in the Manufacturing Industry with the 4th Industrial Revolution. AI has several algorithms that help in collecting and analyzing data in order to help robots to function in specific ways. These techniques include Fuzzy Logic, Genetic Algorithm, Neural Network, etc. In this paper, the role of these algorithms in Mobile Robots is discussed. Based on the review of 74 papers and articles, it is observed that there are no review papers discussing the role of nature-based and conventional algorithms used for navigation in Mobile Robots. The use of different AI techniques for specific applications has been discussed in tabular form in this paper
Anterior crossbite treatment using functional orthopedic appliance: a case report
Get PDFAnterior crossbite can affect primary, mixed, and permanent dentitions. Early treatment is recommended, as it can impact facial, aesthetic, functional, and developmental aspects. The etiology of anterior crossbite is multifactorial, including dental, skeletal, and postural origins. Treatment should be defined based on age and etiology, with various therapeutic resources available for correction. In primary dentition, direct flat tracks, different types of functional orthopedic appliances, quad-helix, and facial mask can be used. In mixed dentition, fixed segmented or continuous orthodontics, elastics, and other devices can be added to the treatment. In permanent dentition, orthognathic surgery may be indicated for adults, especially in cases of anterior crossbite associated with skeletal Class III that cannot be compensated dentally. This case report describes the treatment of early mixed dentition anterior crossbite with a functional orthopedic appliance at the Orthodontic Specialization, Postgraduate Course at Modal college, Belo Horizonte, Minas Gerais, Brazil. After correction, proper chewing functions were reestablished with ideal developmental stimuli
Vibrator with two impacting pairs, one of them in the position of equilibrium
Get PDFIn the dynamic processes taking place in manipulators and robots, impact interactions play an important role. Among them two sided impacts are important. In this paper investigation of dynamic regimes of a system with two impacting surfaces, one of which is in the position of equilibrium is performed. Dynamics in steady state regime for typical parameters of the investigated system having one degree of freedom is investigated. Displacements as functions of time as well as velocities as functions of time for various positions of the impacting surface are presented. Non symmetric impacts enable to reduce the dimensions of the vibrator and to achieve increase of effectiveness of useful impacts of a manipulator. Investigations of the conservative system as well as of the system with forced harmonic excitation are performed
An overview of Baltic Carbon Forum conference 2022
Get PDFBaltic Carbon Forum (BCF) is an annual event sponsored by Nordic Council of Ministers through Nordic Energy Research through their network BASRECCS. BCF 2022 was held on 13th and 14th Oct. in Kaunas, Lithuania. The aim of the BCF 2022 was to enable interested and engaged stakeholders to meet, discuss, share knowledge and experiences, and develop projects. BCF also aims to increase awareness about Carbon Capture Utilization and Storage (CCUS) among younger generations with aim of securing a sustainable future for all. The BCF2022 invited a number of academic and industry experts from the Baltic Sea region countries, which included policymakers, financial institutes, industry representatives and academics for sharing their experiences, conduct discussions and brainstorming sessions to identify gaps with aim of expediting the deployment of a large-scale CC(U)S project in the Baltic Sea Region (BSR). BCF 2022 was attended by 74 participants. There were 38 participants who attended the conference onsite and 36 participants attended the conference online. Participants came form 15 countries, which included Finland, Lithuania, Hungary, Sweden, Poland, Norway, Estonia, Denmark, Latvia, Belgium, Germany, USA, UK, India and South Africa. This paper presents a short summary of all the talks presented at the BCF 2022 conference [1, 2]
Trajectory planning and control algorithm of industrial robot manipulator
Get PDFAs the industrial robot task becomes more complex, the difficulty of trajectory planning and tracking control of manipulator is gradually increasing. To minimize the vibration during the manipulator motion and improve the planning accuracy, the method of quintic polynomial combined with non-uniform B-spline interpolation is studied for joint space (JS) planning. The trajectory tracking system is easily affected by friction nonlinearity and parameters. So a JS trajectory tracking controller based on based on fuzzy neural network (FNN) is designed. Through simulation experiments, the curve obtained by the planning method studied is smoother and the planning error is minimum. The maximum position error is 0.09 rad, and the speed error is not more than 0.1 rad/s. The controller performance test results under different parameters show that the W^, c^, κ^ parameter in FNN can be adjusted in real time, and the value will not affect the performance of the controller. The fluctuation range of trajectory error of different joints is within ±0.2×10-5rad, which indicates that the performance of AFNNC controller studied is better. And its response time is the shortest and its robustness is better when the load changes suddenly