Robotic Systems and Applications
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Plagiocephaly and malocclusion
Get PDFThe term plagiocephaly means oblique head. Most skull deformities are a result of intrapartum or utero molding but can be caused by congenital torticollis and after birth due to persistent head position of newborns staying in one head position for a long time and abusive use of strollers, car seats, car seats, swings. Its prevalence is growing fast, in 30 years it passes from 1 in each 300 babies in early nineties to 16 to 48 % in 2020. The aim of this paper is bringing the light to some serious conditions of treatment protocols in individuals with plagiocephaly. The skull deformity causes facial asymmetry that are not treatable by orthopedic or orthodontic intra or extra oral appliances, nor orthognathic surgery. Well, despite the fact that the patient or the tutors have to be notified of the facial asymmetry that persists, functional limitations will be presented. In more than 30 years of clinical experience treating these patients it was never sought the 4 first permanent molars and the 4 canines in the same Angle’s Class. In one side can be seen Class 1, but on the other it will be finding class 2 or class 3, the case reported exemplifies it, and the worst, mastication guidance will have to be very carefully done since, in most cases if it is tried to adjust the inferior and superior dental midline the vertical asymmetry of the occlusal plane (minimum vertical dimension) will worsen. Really there is no unique treatment protocol and it has to be considered case by case. It is time to deepen the knowledge in this area since the prevalence is growing. Based on the case reported, non-treated plagiocephaly can bring serious limitations to malocclusion treatment results. Further studies are necessary to a better understanding of the situation plagiocephaly versus malocclusion
The impact of occlusal plane rehabilitation on the face of a patient with traumatic peripheral facial paralysis by Timpanic jugular tumor – case report
Get PDFThe musculature of the face is innervated by cranial nerves, each with a motor, sensory and/or both function. The Facial nerve (FN) is responsible for the motor innervation of the muscles of the face. Some branches of the trigeminal nerve are responsible for the sensory part of the facial muscles and other branches act on the motor part of the chewing muscles. Traumatic Facial Paralysis (TFP) is the one where there was section or traction or compression or ischemia of the FN, in surgery for tumor resection or trauma in general. In this case occurs the nerve’s section in one surgery. Facial Paralysis (FP) can be evaluated subjectively through the House and Brackmann classification scale (HB) [1]. It is considered a chronic FP when it persists for a period longer than 6 months and leaves sequelae, such as synkinesis, contractures and lack of complete innervation of some nerve branches. Some patients who evolve with chronic FP may also evolve with alteration of the occlusal plane. The occlusal plane is the meeting point between the antagonist teeth, plane that is in the final stop of the masticatory cycle. The rehabilitation of this plan is performed according to the needs of each patient, in this case was made through implant prostheses
Maintenance decision-making and its relevance in engineering asset management
Get PDFEngineering asset management (EAM) has received a lot of attention in the last few decades. Despite this, industries struggle to identify the best strategies for maintaining assets. The decision-making around selecting a relevant maintenance strategy generally considers factors like risk, performance and cost. Risk management is, usually, largely subjective and industries consequently make investments in a subjective manner, making the allocation of budget unstructured and arbitrary. Generally, industries focus only on either overt risks or basic performance of assets, thus creating uncertainties in the decision-making process. Recently, however, maintenance decision-making has evolved from a subjective assessment, chiefly dependent on expert opinions, to utilizing live-data-sensor technology. The attitude towards component failures and how to address them has changed drastically with the evolution of maintenance strategies. Additionally, the emergence and use of several tools and models have assisted the drafting and implementation of effective maintenance strategies. These advancements, however, have only considered discrete parameters while modelling, instead of using an integrated approach. One of the primary factors which can address this shortfall and make the decision-making process more robust is the economic element. To enable an effective decision-making process, it is imperative to consider quantifiable determinants and include economic parameters while drafting maintenance policies. This paper reviews maintenance decision-making strategies in EAM and also highlights its relevance through an economic lens
Multi-source partial discharge pattern recognition in GIS based on Grabcut-MCNN
Get PDFPartial discharge (PD) surveillance constitutes a pivotal methodology for diagnosing insulation failures in electrical equipment. Enhancing comprehensively the precision of identifying PD anomalies in Gas Insulated Switchgear (GIS) is of paramount significance for ensuring the steady functioning of power grids. This study introduces a novel framework that integrates Phase-Resolved PD Graph Segmentation (PRPD-Grabcut) with a tailored MobileNets-based Convolutional Neural Network (MCNN) to classify GIS-related PD issues. Leveraging image segmentation via PRPD-Grabcut, crucial features are extracted from PRPD diagrams, which then facilitate the construction of the MCNN model. This model employs depth-wise separable convolutions alongside inverted residual architectures to tackle the vanishing gradient dilemma inherent in Deep Convolutional Neural Networks (DCNNs) during GIS PD pattern discernment. Upon the model's subsequent training and validation, empirical evidence illustrates that the PRPD-Grabcut-MCNN hybrid significantly alleviates the computational load and storage requisites of the model, concurrently enhancing the recognition precision and expediting the training process of the neural network. Relative to diverse established lightweight neural network architectures, MCNN manifests superior performance in terms of recognition accuracy, reduced cross-entropy loss, and expedited training duration
Detection method for underwater dock joints: underwater sonar imaging based on 3D technology
Get PDFIn the detection of surface defects in underwater structures, traditional methods using manual diving are inefficient. Equipment such as underwater high-definition cameras and underwater laser imaging face significant signal attenuation in deep and turbid environments, and the information contained in two-dimensional sonar images is limited, making it difficult to meet accuracy requirements. To address these shortcomings, a detection method based on sonar imaging for underwater docks using three-dimensional (3D) reconstruction is proposed. This method first reduces environmental interference through preprocessing. Then, emit sound waves towards the underwater target and receive the returning signals, which are converted into digital signals. Next, perform 3D modeling and visualization. Finally, a detailed analysis of the 3D images is conducted to identify, analyze, and assess the severity and distribution patterns of defects. The experimental results show that the 3D scanning sonar imaging detection technology can effectively detect targets and accurately identify misalignment in caisson joints, meeting practical application requirements
Self-synchronisation of vibration exciters of a biharmonic vibration drive
Get PDFThe paper considers the practical possibility of self-synchronisation of two biharmonic unbalanced vibration exciters mounted on a solid body with plane oscillations. The problem is solved by the method of direct separation of motions. The equations for slow processes of establishing synchronous modes of rotation of the exciters are obtained; expressions for vibration torque; the vibration coupling coefficient and the condition for the existence of an synphase mode of motion. It is shown that the latter condition is relatively “soft”. An expression for the vibration torque is obtained for the case of “stuck” velocity of a biharmonic exciter in the resonance zone of a vibration machine. Recommendations for selecting the parameters of the vibration drive are given. The analytical conclusions are confirmed by computer modelling
Simulation of locomotion conditions of an enhanced vibration-driven in-pipe robot
Get PDFThe paper aims to analyze the improved design of an in-pipe vibration-driven robot, which is equipped with a self-locking mechanism, electromagnetic exciter, and size-adapting devices. The study focuses on examining the robot’s locomotion conditions at different working regimes. The research methodology contains four main stages: analysis of the design peculiarities of the enhanced wheeled in-pipe vibration-driven robot; developing a simplified dynamic diagram and deriving the differential equations to describe its locomotion conditions; carrying out numerical modeling with the help of Mathematica software to analyze the robot’s basic dynamic parameters; conducting virtual experiments and testing the robot locomotion characteristics by means of the computer simulation in SolidWorks Motion software. The results obtained include the time-based data on the robot’s displacement, speed, acceleration, and consumed power under different operating conditions, such as varying forced frequencies and excitation force amplitudes. The novelty of this investigation lies in identifying efficient working regimes for the improved wheeled vibration-driven robot intended for moving inside the pipelines. Future research will focus on developing a full-scale experimental prototype of the robot and conducting laboratory investigations at different working regimes. The findings of this research are valuable for scientists and engineers involved in the study and design of similar vibration-driven locomotion systems
Dynamic performance of compound vibration damping device for sport fitness equipment
Get PDFComposite vibration damping is a crucial aspect in enhancing the performance of shock absorber, with potential for significant application in multi-degree-of-freedom sports facilities. Based on the finite element method, the modal analysis, harmonic response analysis and stiffness analysis of metal rubber shock absorber were realized, and the parameters of natural frequency, acceleration transmissibility and average stiffness were verified. Through ABAQUS, the finite element model of shock absorber was established and reasonably simplified, and the influence of wire diameter and relative density on the comprehensive performance was studied under the condition of prestress modal analysis. The results indicate that the shock absorber with a relative density of 0.35 exhibits higher average stiffness, but lower energy dissipation coefficient. Additionally, it shows larger peak values for natural frequency and acceleration transmissibility, but reduced damping. The simulation findings are in line with the experimental results, demonstrating the accurate acquisition of nonlinear mechanics and dynamic response properties of metal rubber shock absorber
Assessment of the impact of TE33A diesel locomotive wheelsets on the railway track in a straight section of the track
Get PDFThe purpose of the article is an experimental study of the impact of the wheelsets of a mainline diesel locomotive on the railway track on straight sections of the track. The measurements were performed on a vibration measuring device consisting of MV25 DV type sensors and an oscillation converter for a digital signal. It is proved that the indicators of dynamic characteristics comply with regulatory requirements. As a result of the conducted research, digital data was collected from the ADC and general monitoring was carried out. Measurement and signal processing are carried out using special software of a personal computer such as a “Notebook”. Vertical static load of a wheelset of a railway rolling stock unit on rails: the load of a railway rolling stock unit on rails attributed to one wheelset, taking into account the actual location of the center of gravity of the superstructure
Simulation analysis of helicopter rotor blade based on fluid-structure coupling
Get PDFSince the helicopters are required to fulfil many different attitudes during actual flight and are exposed to low amplitude and high number of cycles of vibration loads for a long period of time, the stresses on its rotor structure will be more complicated, which will lead to the rotor blades being subjected to larger stresses and causing fatigue damage. This paper proposes a combination of fluid-solid coupling and nCode fatigue simulation of helicopter rotor blade structure to study the stress distribution, danger point and fatigue life of rotor blades in hovering and forward flight state, so as to provide a reference basis for the judgement of helicopter rotor blade fatigue damage and the enhancement of safety performance. The results show that the maximum stress of the helicopter in the forward flight state is larger than that in the hovering state, and the maximum stress of the rotor blade in the forward flight state of the helicopter is located at the root of the blade as 166.89 MPa; and the fatigue life in the two states is obtained by the joint simulation method of Workbench-nCode, and the fatigue life in the forward flight state is reduced by 0.726 % compared with that in the hovering state. Therefore, the combined method of fluid-solid coupling and nCode fatigue simulation proposed in this paper can provide an effective research method for the design and optimisation process of helicopter rotor blades