Robotic Systems and Applications
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Triangular state stress and deformation analysis of deformable tracked wheel
Get PDFThe Variable Morphology Wheel-Track Mechanism (VMWTM) is an innovative mobile platform design designed to overcome the limitations of traditional track and wheel designs in different terrains and mission requirements. Based on the importance of the crawler wheel in the tracked vehicle, the vehicle transmission shaft transmits the power and torque of the power source to the crawler chassis, so the overall working performance of the vehicle depends to a certain extent on the performance of the crawler wheel. In-depth and detailed research on the structure of the track wheel module is an important issue in the current vehicle design and manufacturing work. Based on the relevant theories and technologies of the finite element method, this paper conducts in-depth analysis and design. Taking the whole crawler wheel mechanism and the key components as the analysis object, the basic research method is the finite element method. The working principle of the crawler wheel is analyzed, and the load calculation, stress characteristics and structural strength of the key components of the triangular crawler wheel module are deeply explored according to the technical requirements and actual working conditions
Analysis and optimization of pre-stressed modal features of ship anchor support parts
Get PDFIn order to solve the problems of excessive weight and unreasonable structure of anchor machine parts caused by traditional design methods, a lightweight optimization method was proposed based on pre-stressed modal analysis. The design variables were determined, and the parameterized model was established by using ANSYS Workbench. Under ultimate load conditions, the strength of wall frame board and lower box bodies was simulated and calculated. Through modal analysis, the discretized natural frequencies under different design variables could be obtained. The multi-objective genetic algorithm and sequence quadratic programming were respectively used to calculate the lightweight analysis model. The results showed that the weight of the supporting components in ship anchor can be reduced by more than 5 % without reducing strength and equivalent stiffness
Low-level laser therapy parameters in the treatment of Orofacial pain in temporomandibular disorder
Get PDFTemporomandibular disorder (TMD) comprises a group of dysfunctions of the masticatory system involving joint, myofascial, and even sensory alterations. The main symptom of TMD is orofacial pain, which has a negative impact on the quality of life of TMD sufferers, affecting their productivity at work and school, the quality of their sleep, their appetite, and their satisfaction with life. An alternative for the treatment of TMD is the low-level laser therapy (LLLT), which stimulates cellular functions and promotes therapeutic effects. However, there is no consensus in the literature. Objective: This review aimed to elucidate the parameters of low-level laser therapy in the treatment of orofacial pain in patients with temporomandibular disorder. Methods: A search was carried out for scientific articles published between 2013 and 2023 in the MEDLINE, PEDro, LILACS and SciELO databases. Results: A total of 21 studies were previously selected and after the eligibility criteria, 10 studies were included. Can be suggest a protocol for treating patients with temporomandibular disorder by low-level laser therapy with the following parameters: infrared wavelength, energy density less than 10 J/cm2, output power from 100 to 250 mW and at least 8 sessions of treatment. Conclusion: The low-level laser therapy improves orofacial pain in patients with temporomandibular disorder
Energy storage technologies and their combinational usage in micro/mini unmanned aerial vehicles: a review
Get PDFAs the world population increases, energy consumption extensively increases in every field. Energy is a need in several applications, and depending on its importance, its production should be renewable and clean. In order to meet energy requirements sustainably nowadays various alternative energy resources and improvements are recommended in each sector. One of the environmental steps taken in the aviation industry is the improvement of the propulsion systems and the resources used. For this purpose, the use of electrical energy, a more sustainable option than the energy obtained from fossil fuels, is suggested. In order for electrical energy to be used efficiently, it must be stored. This article reviews energy storage technologies used in aviation, specifically for micro/mini Unmanned Aerial Vehicles (UAVs). Combinational energy storage technologies in hybrid propulsion system architectures and their individual usage in all-electric propulsion system architectures are examined. New-generation propulsion technologies are also evaluated and classified in detail
Checking the manufacturing of Simões Network 10 – SN10 through surface electromyography (sEMG) – case report study
Get PDFUse of functional orthopedic appliances (FOA) in the treatment of malocclusion and Temporomandibular Disorders (TMD) has been proved to be effective but there is still questions to be answered like the muscular action of the referred appliances. The aim of this study is checking through a proven protocol of surface electromyography (sEMG) to study muscular action of FOA to check to check if it is correctly manufactured. The appliance studied is a Simões Network 10 – SN10 to treat Class II malocclusion of retrognathia. The sEMG was collected 1 patients with class II malocclusion with retrognathia who belong to a 164 volunteers with malocclusion, in two times T1 before installation of the FOA in mouth, T2 15 minutes after the FOA installation in the mouth. sEMG data of bilateral masseter, bilateral temporal and bilateral suprahyoid muscles using conditioner signals module from Lynx Electronics Ltda with 8 channels, model EMG1000; software AqDAnalysis 4,18 from Lynx Electronics Ltda.; Software Lynx BioInspector 1,8r; passive surface electrodes (Ag/AgCl) from Noraxon Dual Electrodes (USA); dischargeable reference electrodes Kendall Meditrace (Ag/AgCl) – Canada were used for the sEMG measurements. Frequency calibration was 2000 Hz, with 2048 sample by channel and time 1,024 seconds, and filters regulation was 20 Hz and 1000 Hz. With the FOA in the mouth all measurements improved with a more simetrical sEMG in T2 in rest and isometric contraction measurements. The protocol used to check the manufacturing of functional orthopedic appliances using surface EMG proved to be a valid tool in this case report study. Further investigations are needed to confirm this protocol and check if the same happens with other types of functional orthopedics appliances
An improved semi-supervised prototype network for few-shot fault diagnosis
Get PDFThe collection of labeled data for transient mechanical faults is limited in practical engineering scenarios. However, the completeness of sample determines quality for feature information, which is extracted by deep learning network. Therefore, to obtain more effective information with limited data, this paper proposes an improved semi-supervised prototype network (ISSPN) that can be used for fault diagnosis. Firstly, a meta-learning strategy is used to divide the sample data. Then, a standard Euclidean distance metric is used to improve the SSPN, which maps the samples to the feature space and generates prototypes. Furthermore, the original prototypes are refined with the help of unlabeled data to produce better prototypes. Finally, the classifier clusters the various faults. The effectiveness of the proposed method is verified through experiments. The experimental results show that the proposed method can do a better job of classifying different faults
Modal analysis and structural noise control of vehicle body frame
Get PDFThe structural noise inside the vehicle cabin is mainly low-frequency vibration, which is closely related to the modal characteristics of the vehicle frame. The finite element method was used to simulate and calculate the body frame under free modal conditions, and the first four effective modal shapes were obtained. The calculation error of the natural frequencies was verified through modal experiments. Taking structural stiffness into account, a sound-structure coupled model was established. The suspension connection point was selected as the excitation point, and a one-way dynamic load was applied to obtain the noise and vibration responses of the front and rear rows. Based on the modal analysis results, the top-roof reinforcement scheme was adopted to verify the noise suppression effect of the structure. The results show that the optimized structure can effectively suppress structural noise, which plays an important role in improving the NVH characteristics
Vector analysis of unmanned aircraft sea surface imaging characterization based on ISAR
Get PDFUtilization of airborne Inverse-Synthetic-Aperture-Radar (ISAR) for detection of moving targets on the sea surface is studied in this paper. In order to systematically analyze the characterization of radar imaging in the presence of both motion and observation uncertainty of a target, this study incorporates the Bayes-PRM multi-query algorithm for fusing ISAR multi-sensing information. The algorithm isochronously samples the physical quantities, such as UAV position, altitude, pitch angle, and velocity as a sequence of multivariate groups, and converts the time-series data of the trajectories into distributional features in graph theory. The coupled edge weights and Alternating Direction Method of Multipliers (ADMM) are introduced through the coupling framework combined with the ambient graph. With ADMM, the quadratic penalty term is used to achieve a simple linear function, and subproblems involving amplitude, linear velocity, and yaw angle can be embedded in a sequential solution scheme. The quality of the primal and dual solutions is then improved in an iterative manner to achieve vector analysis of the UAV. The potential maneuvering region of the target is fitted to a Gaussian-Wiener stochastic movement model, which in turn yields the detection expectation through point set coverage. By analyzing the tracking simulation results and diffraction theory, the experimental results are transformed into a function of the UAV multi-vector, and the angular linearization model of the multi-vector under the radar image is developed, which solves the optimal elevation angle and the optimal path for the maximum scanning radius of the airborne radar. The nominal trajectory of the UAV is effectively obtained, which confirms the improvement of the credibility of ISAR in target detecting. Through the proposed model, the results of object detection accuracy were improved
Tensor analysis of tornadoes: a new analytical and numerical model
Get PDFThis research proposes a new mathematical formulation of tornadoes based on the theory of tensor analysis and simulation in a non-inertial dynamics framework, both in two and three dimensions. This model may show the spherical upward movement of air in a tornado without taking into account vertical convection. A tornado requires several elements, including geocentric latitude, the Coriolis effect, increased airspeed in the upper atmosphere, and increased air pressure. Computing the three-dimensional location of the tornado or hurricane, as well as the mathematical models of airflow motion and the Earth's rotation in three-dimensional (3D) space, can determine a tornado's airflow characteristics. To show tornado patterns, we employed computer software that computed motion dynamics and did numerical computations. The results of 2-D modeling and simulation indicated that the greater the initial tornado angular speed, the larger the tornado area. Three-dimensional modeling and simulation also show that tornadoes are more powerful at higher geocentric latitude angles. The novelty of this study is that this model can be used to explain tornado patterns. In our research, we combine tensor analysis, computational modeling, as well as 2D and 3D simulations for simulating tornadoes for the first time. The scientific application of this finding is that researchers at the Meteorology, Climatology, and Geophysics Agency will be able to analyze a tornado and geophysical phenomena more readily with simulations and models
Optimizing and reliability analysis by firefly and genetic algorithms for a quadcopter
Get PDFOur study aims to obtain the highest level of reliability for a quadcopter, taking financial and mass limitations into account, to achieve the highest level of reliability with the lowest mass and cost. For this purpose, we first calculated the reliability and the relationships that govern it, and based on these relationships, we determined the reliability of the quadcopter subsystems. In order to achieve the highest level of reliability, we utilized optimization algorithms. It is possible to increase the reliability of a system through several methods, such as enhancing the quality of parts and components, using surplus components, improving the quality of parts and components by always using surplus components, and redesigning the system. This study examines the possibility of increasing quadcopter reliability by using additional parts and optimizing it using the firefly algorithm. Lastly, in order to validate the results obtained from the firefly algorithm, we implemented the problem once again using the genetic algorithm and compared the results obtained from both algorithms. After 20 times of running the algorithms, the optimal reliability values were 0.99925 for the firefly algorithm and 0.99999 for the genetic algorithm