Kinematic Devices Research Articles

ФОРМИРОВАНИЕ РАСЧЕТНЫХ СХЕМ ОБОБЩЕННЫХ КИНЕМАТИЧЕСКИХ УСТРОЙСТВ, ПРИЦЕЛЬНО РЕГУЛИРУЮЩИХ СПЕКТР ЧАСТОТ СОБСТВЕННЫХ КОЛЕБАНИЙ УПРУГИХ СИСТЕМ С КОНЕЧНЫМ ЧИСЛОМ СТЕПЕНЕЙ СВОБОДЫ МАСС, У КОТОРЫХ НАПРАВЛЕНИЯ ДВИЖЕНИЯ ПАРАЛЛЕЛЬНЫ, НО НЕ ЛЕЖАТ В ОДНОЙ ПЛОСКОСТИ

To date, for some elastic systems with a finite number of degrees of mass freedom, in which the directions of mass movement are parallel and lie in the same plane, methods have been developed for creating additional generalized targeted constraints and generalized targeted kinematic devices. Each generalized targeted constraint increases, and each generalized targeted kinematic device reduces the value of only one selected natural frequency to a predetermined value, without changing the remaining natural frequencies and natural modes. Earlier, for elastic systems with a finite number of degrees of mass freedom, in which the directions of mass motion are parallel, but do not lie in the same plane (for example, plates), an approach for the computing of a matrix of additional stiffness and a method for the development of computational schemes of additional generalized targeted constraints were developed. Also earlier, for such systems, an approach was proposed for the computing of a special matrix with allowance for additional inertial forces that determine a generalized targeted kinematic device. At the same time, the method of development of computational schemes of kinematic devices was not proposed. The first part of the paper was devoted to approach, that made it possible to develop computational schemes of generalized targeted kinematic devices for such systems as well. A variant of the computational scheme of constraint for the rod system with one degree of activity was considered. Some special properties of such targeted kinematic devices were revealed. The distinctive second part of the paper is devoted to corresponding samples of analysis.

ФОРМИРОВАНИЕ РАСЧЕТНЫХ СХЕМ ОБОБЩЕННЫХ КИНЕМАТИЧЕСКИХ УСТРОЙСТВ, ПРИЦЕЛЬНО РЕГУЛИРУЮЩИХ СПЕКТР ЧАСТОТ СОБСТВЕННЫХ КОЛЕБАНИЙ УПРУГИХ СИСТЕМ С КОНЕЧНЫМ ЧИСЛОМ СТЕПЕНЕЙ СВОБОДЫ МАСС, У КОТОРЫХ НАПРАВЛЕНИЯ ДВИЖЕНИЯ ПАРАЛЛЕЛЬНЫ, НО НЕ ЛЕЖАТ В ОДНОЙ ПЛОСКОСТИ

To date, for some elastic systems with a finite number of degrees of mass freedom, in which the directions of mass movement are parallel and lie in the same plane, methods have been developed for creating additional generalized targeted constraints and generalized targeted kinematic devices. Each generalized targeted constraint increases, and each generalized targeted kinematic device reduces the value of only one selected natural frequency to a predetermined value, without changing the remaining natural frequencies and natural modes. Earlier, for elastic systems with a finite number of degrees of mass freedom, in which the directions of mass motion are parallel, but do not lie in the same plane (for example, plates), an approach for the computing of a matrix of additional stiffness and a method for the development of computational schemes of additional generalized targeted constraints were developed. Also earlier, for such systems, an approach was proposed for the computing of a special matrix with allowance for additional inertial forces that determine a generalized targeted kinematic device. At the same time, the method of development of computational schemes of kinematic devices was not proposed. The first part of the paper was devoted to approach, that made it possible to develop computational schemes of generalized targeted kinematic devices for such systems as well. A variant of the computational scheme of constraint for the rod system with one degree of activity was considered. Some special properties of such targeted kinematic devices were revealed. The distinctive second part of the paper is devoted to corresponding samples of analysis.

A systematic evaluation of an RTK-GPS device for wearable augmented reality

Global Positioning Satellite (GPS) systems sample points on the Earth’s surface with meter accuracy. Real-Time Kinematic (RTK) devices improve GPS performances by providing real-time correction data from ground stations, achieving centimeter accuracy. Reliable tracking approaches are essential for Augmented Reality (AR) applications, especially for outdoor scenarios, which still present unsolved challenges. AR handheld tracking capabilities have been greatly improved by integrating visual tracking approaches with RTK devices, whereas little is known about combining wearable AR interfaces with RTK systems. Although wearable AR devices are intrinsically designed for AR applications, their performance dramatically reduces in large outdoor areas, comprising the user experience. Hence, this paper provides a rigorous evaluation of a small-size RTK device that does not need any additional software integration to collect positional data. The main goal of the assessment is to verify whether its integration with a wearable AR device is advantageous or not. The evaluation has been performed considering both static and dynamic scenarios in open-sky and urban areas. The results show that the RTK device can achieve 1 cm accuracy when used in open-sky areas. In contrast, its accuracy dramatically reduces in the proximity of buildings and obstacles, showing average errors ranging from 76 to 2561%. Since wearable AR devices have an average accuracy of 2 cm, the outcomes indicate that RTK devices should be combined with wearable AR devices only when the RTK device is far from obstacles. On the contrary, the positional data should be completely avoided when barriers surround the RTK device.

DEVELOPMENT OF COMPUTATIONAL SCHEMES OF GENERALIZED KINEMATIC DEVICES THAT PRECISELY REGULATE THE NATURAL FREQUENCY SPECTRUM OF ELASTIC SYSTEMS WITH A FINITE NUMBER OF DEGREES OF MASS FREEDOM, IN WHICH THE DIRECTIONS OF MOTION ARE PARALLEL, BUT DO NOT LIE IN THE SAME PLANE

To date, for some elastic systems with a finite number of degrees of mass freedom, in which the directions of mass movement are parallel and lie in the same plane, methods have been developed for creating additional generalized targeted constraints and generalized targeted kinematic devices. Each generalized targeted constraint increases, and each generalized targeted kinematic device reduces the value of only one selected natural frequency to a predetermined value, without changing the remaining natural frequencies and natural modes. Earlier, for elastic systems with a finite number of degrees of mass freedom, in which the directions of mass motion are parallel, but do not lie in the same plane (for example, plates), an approach for the computing of a matrix of additional stiffness and a method for the development of computational schemes of additional generalized targeted constraints were developed. Also earlier, for such systems, an approach was proposed for the computing of a special matrix with allowance for additional inertial forces that determine a generalized targeted kinematic device. At the same time, the method of development of computational schemes of kinematic devices was not proposed. The distinctive paper is devoted to approach, that makes it possible to develop computational schemes of generalized targeted kinematic devices for such systems as well. A variant of the computational scheme of constraint for the rod system with one degree of activity, is considered. Some special properties of such targeted kinematic devices are revealed.

Consensus Head Acceleration Measurement Practices (CHAMP): Laboratory Validation of Wearable Head Kinematic Devices

Wearable devices are increasingly used to measure real-world head impacts and study brain injury mechanisms. These devices must undergo validation testing to ensure they provide reliable and accurate information for head impact sensing, and controlled laboratory testing should be the first step of validation. Past validation studies have applied varying methodologies, and some devices have been deployed for on-field use without validation. This paper presents best practices recommendations for validating wearable head kinematic devices in the laboratory, with the goal of standardizing validation test methods and data reporting. Key considerations, recommended approaches, and specific considerations were developed for four main aspects of laboratory validation, including surrogate selection, test conditions, data collection, and data analysis. Recommendations were generated by a group with expertise in head kinematic sensing and laboratory validation methods and reviewed by a larger group to achieve consensus on best practices. We recommend that these best practices are followed by manufacturers, users, and reviewers to conduct and/or review laboratory validation of wearable devices, which is a minimum initial step prior to on-field validation and deployment. We anticipate that the best practices recommendations will lead to more rigorous validation of wearable head kinematic devices and higher accuracy in head impact data, which can subsequently advance brain injury research and management.

Development of an Artificial Neural Network for the Detection of Supporting Hindlimb Lameness: A Pilot Study in Working Dogs.

Simple SummaryMany of the rules considered valid in the ambit of lameness detection in domestic animals are mainly subjective or acquired after extended clinical experience. Thus, it is necessary to develop tools and/or technologies to provide objective data to discern between sound and lame animals. The main objective of this study is to develop an artificial neural network by analyzing data obtained from an inertial sensor in order to discriminate between sound and lame dogs. After different system adjustments, the neural network has been able to correctly determine whether dogs were lame in about 86% of cases. Furthermore, a web app was developed to manage and follow the different cases. An artificial neural network was designed and developed to analyze spatial data from inertial sensors and to detect motion alterations in dogs with unilateral lameness. Displayed within a user-friendly, intuitive web app, the system could be a useful tool for lameness detection for veterinary clinicians.Subjective lameness assessment has been a controversial subject given the lack of agreement between observers; this has prompted the development of kinetic and kinematic devices in order to obtain an objective evaluation of locomotor system in dogs. After proper training, neural networks are potentially capable of making a non-human diagnosis of canine lameness. The purpose of this study was to investigate whether artificial neural networks could be used to determine canine hindlimb lameness by computational means only. The outcome of this study could potentially assess the efficacy of certain treatments against diseases that cause lameness. With this aim, input data were obtained from an inertial sensor positioned on the rump. Data from dogs with unilateral hindlimb lameness and sound dogs were used to obtain differences between both groups at walk. The artificial neural network, after necessary adjustments, was integrated into a web management tool, and the preliminary results discriminating between lame and sound dogs are promising. The analysis of spatial data with artificial neural networks was summarized and developed into a web app that has proven to be a useful tool to discriminate between sound and lame dogs. Additionally, this environment allows veterinary clinicians to adequately follow the treatment of lame canine patients.

Using Real-Time Kinematic (RTK) Devices to Show a Limited Effect of Boldness and Fearfulness on Social Proximity in Sheep Grazing at Pasture

Sheep are gregarious animals that can form close inter-individual relationships. Social bonds are affected by environmental and within-animal factors, but there is limited understanding of individual factors that influence social relationships, in part due to the challenges of accurately measuring individual social proximity within a group. This study used geospatially precise RTK-GNSS localization devices (Real-Time-Kinematic Global Navigation Satellite System) to evaluate social proximity between individuals with different personality traits in small sheep flocks. First, unsupervised clustering algorithms were used to categorize 78 individual Merino sheep (from a research flock of 108 grazed together for 11 months prior) based on their behavior measured in four behavioral tests: arena, novel object, flight speed, and isolation box. Sixty-five sheep were then categorized into five cohorts of 13 individuals each (clustered into three bold, six bold/fearful, and four fearful animals per cohort). Bold/fearful animals were bold toward a novel object but fearful of a human. Sheep within a single cohort were released into a 0.70 Ha test paddock with RTK-GNSS devices attached to their backs for 3 days to monitor relative positions. All cohorts were tested sequentially over a 5-week period. Social network analyses of GNSS locational data with a distance threshold of up to 30 m for all cohorts together showed no significant effect of personality traits (P= 0.11). There were, however, some significant but inconsistent differences in distances based on personality traits within separate cohorts [i.e., cohorts 1, 3, 4 (P≤ 0.02), cohorts 2, 5 (P≥ 0.44)]. When GNSS locational data were analyzed with a distance threshold of up to 2 m (day 2 excluded from all cohorts due to missing values), there was a significant effect of personality traits (P= 0.01) across all cohorts combined. The bold animals showed greater distances from each other relative to their distances from fearful or bold/fearful individuals. Additionally, regardless of personality traits, the average distance between animals decreased 2.2 m over the 3 test days. Social interactions in sheep flocks may be influenced by personality traits of fearfulness and boldness, but further research with larger numbers of sheep across varying environments is needed.

AIMED CONTROL OF THE FREQUENCY SPECTRUM OF EIGENVIBRATIONS OF ELASTIC PLATES WITH A FINITE NUMBER OF DEGREES OF MASS FREEDOM BY INTRODUCING ADDITIONAL GENERALIZED KINEMATIC DEVICES

As is known, targeted regulation of the frequency spectrum of natural vibrations of elastic systems with a finite number of degrees of mass freedom can be performed by introducing additional generalized constraints and generalized kinematic devices. Each targeted generalized constraint increases, and each generalized kinematic device reduces the value of only one selected natural frequency to a predetermined value, without changing the remaining natural frequencies and all forms of natural vibrations (natural modes). To date, for some elastic systems with a finite number of degrees of freedom of masses, in which the directions of mass movement are parallel and lie in the same plane, special methods have been already developed for creating additional constraints and generalized kinematic devices that change the frequency spectrum of natural vibrations in a targeted manner. In particular, a theory and an algorithm for the creation of targeted generalized constraints and generalized kinematic devices have been developed for rods. It was previously proved that the method of forming a matrix of additional stiffness coefficients, specifying targeted generalized constraint, in the problem of natural vibrations of rods can also be applied to solving a similar problem for elastic systems with a finite number of degrees of freedom, in which the directions of mass movement are parallel, but do not lie in the same plane. In particular, such systems include plates. The distinctive paper shows that the method of forming a matrix for taking into account the action of additional inertial forces, specifying targeted kinematic devices in the problem of natural vibrations of rods can also be applied to solving a similar problem for elastic systems with a finite number of degrees of freedom, in which the directions of mass movement are parallel, but do not lie in the same plane. However, the algorithms for the creation of targeted generalized kinematic devices developed for rods based on the properties of rope polygons cannot be used without significant changes in a similar problem for plates. The method of creation of computational schemes of kinematic devices that precisely change the frequency spectrum of natural vibrations of elastic plates with a finite number of degrees of mass freedom is a separate problem and will be considered in a subsequent paper.

Precision control for eigen-frequency of elastic plates with finite number of mass degrees of freedom by using additional generalized connections and kinematic devices

Прицельное регулирование спектра частот собственных колебаний упругих пластин с конечным числом степеней свободы масс путём введения дополнительных обобщённых связей и обобщённых кинематических устройств

Validation of Real-Time Kinematic (RTK) Devices on Sheep to Detect Grazing Movement Leaders and Social Networks in Merino Ewes.

Understanding social behaviour in livestock groups requires accurate geo-spatial localisation data over time which is difficult to obtain in the field. Automated on-animal devices may provide a solution. This study introduced an Real-Time-Kinematic Global Navigation Satellite System (RTK-GNSS) localisation device (RTK rover) based on an RTK module manufactured by the company u-blox (Thalwil, Switzerland) that was assembled in a box and harnessed to sheep backs. Testing with 7 sheep across 4 days confirmed RTK rover tracking of sheep movement continuously with accuracy of approximately 20 cm. Individual sheep geo-spatial data were used to observe the sheep that first moved during a grazing period (movement leaders) in the one-hectare test paddock as well as construct social networks. Analysis of the optimum location update rate, with a threshold distance of 20 cm or 30 cm, showed that location sampling at a rate of 1 sample per second for 1 min followed by no samples for 4 min or 9 min, detected social networks as accurately as continuous location measurements at 1 sample every 5 s. The RTK rover acquired precise data on social networks in one sheep flock in an outdoor field environment with sampling strategies identified to extend battery life.

JOURNEY INTO THE WORLD OF SCIENCE AND ART ON A PLANTIGRADE MACHINE

The article shows how the computer mathematical program Mathcad allows to solve mechanics problems, in particular, kinematics problems by a new method. The procedure for optimizing the parameters of the Tchebyshev plantigrade machine is described — the calculation of the lengths of its parts, so that the machine will move without vertical pushes. A technique of hybrid solution of mathematical problems on a computer is discussed, where analytical (symbolic) and numerical methods are used alternately or in parallel. A new trend in visual arts is presented, associated with the representation of the trajectory of the motion of kinematic devices.

Kinematic Analysis of a HHSHH Spatial Mechanism by Generated Surfaces

Spatial mechanisms are the most general category of kinematic devices. They offer the greatest capability to accomplish any desired kinematic task. A mechanism exerts forces and moments on its supporting frame, which result in vibration. Balancing of shaking forces and shaking moments in mechanisms is important in order to improve their dynamic performance and fatigue life by reducing vibration, noise and wear. In the present paper the kinematic analysis of a spatial HHSHH mechanism is done by the method of Generated Surfaces, to get the velocities and accelerations of its various links which is necessary for the estimation of inertia forces in that mechanism.

Towards a new monitoring system to detect illegal steps in race-walking

This study aims to develop an innovative approach based on a wearable inertial system, which enables objective evaluations on the of loss of ground contact in race-walking, in order to assist coaching and judging. The architecture of the system, its positioning on the human body and functional requirements were defined through a Kansei Engineering approach by using a significant sample of athletes, coaches and judges within the race-walking environment. The analysis of variance supports decisions concerning the optimal system architecture consisting of an inertial sensor positioned on the centre-of-mass of the subject and a control unit. The selected device was then validated in laboratory conditions by means of an integrated system, including dynamic (680 Hz) and kinematic (340 Hz) devices, which are more accurate than the inertial system (200 Hz). The experiment was carried out at the Fraunhofer JL IDEAS-MISEF at CESMA, Laboratory of Advanced Measures on Ergonomics and Shapes of the University of Naples Federico II where four elite race walkers performed 60 test-runs according to a well-defined experimental protocol. Results proved that the inertial system could improve the accuracy in detecting illegal steps. Through statistical classification, it was found that the proposed approach has achieved encouraging results in comparison with state of the art approaches and could be a good architecture to develop a valuable tool to assist experts.

ПРИНЦИПЫ КОМПОНОВАНИЯ АВТОМАТИЧЕСКИ СМЕННЫХ ЛАЗЕРНЫХ МОДУЛЕЙ ПРИ РЕАЛИЗАЦИИ ТЕХНОЛОГИЙ ЛАЗЕРНОЙ ОБРАБОТКИ НА СТАНКАХ С ЧПУ

The article is devoted to the development of plug-in modules for automatically implementing the laser processing technology on CNC machines. At the heart of solutions used element base fiber lasers. Proposed technical solution of the device in which the optical system, the collimator and the laser emitter in the form of a single unit, composed of a single block, the parameters of each of which is determined by the requirements of the customer. When this module is replaceable and is working CNC machining cycles can be set in the tool magazine of the machine. The module is mounted in the spindle of the machine tool automatically stores the command NC system, and the radiation source is passed directly outside the working area of the machine. Communication with the module is provided by fiber optic cable. The proposed technical solution will be in demand in the market of industrial services, due to fold reduction in capital intensity, as there is no need to purchase a separate position of the laser center provides high performance and precision machining, no additional transportation and reinstallation of parts, reduced loss of time to process all the details. With reference to this article the methodology proposed are devices for laser treatment and are given based on the principle of modular build composition. The principle of modular build composition lies kinematic analysis devices, which allows, based on customer requirements, define a set of blocks for build composition device in the final state of delivery to the customer. The development of this device is the ability to study design at the stage of analysis and modernization of existing designs, and at the stage of preparation of the offer to the customer.

Kinematic analysis of a spatial mechanism for estimating shaking effects

Spatial mechanisms are the most general category of kinematic devices. They offer the greatest capability to accomplish any desired kinematic task. A mechanism exerts forces and moments on its supporting frame, which result in vibration. Besides of its effect on efficiency, reducing vibration has become inevitable in the current industrial environment where stern standards on noise and vibration prevail. Balancing of shaking forces and shaking moments in mechanisms is important in order to improve their dynamic performance and fatigue life by reducing vibration, noise and wear. The analysis and synthesis of spatial mechanisms which involves extensive vector mathematics and linear algebra is to be simplified to be taught to engineers in undergraduate education. In the present paper the kinematic analysis of a spatial four-link RSCR mechanism is done to get the velocities and accelerations of its various links which is necessary for the estimation of inertia forces in a mechanism.

무선 센서를 활용한 요추 가동 범위의 실시간 3차원 측정

Lumber spine range of motion has been used to measure of physical and functional impairment by various tools from a ruler to 3D kinematic devices. However, pre-existing tools have problems in either movement or accuracy and reliability limitations. Accurate devices are limited by fixed space whereas simple devices are limited in measuring complex movements with less accuracy. In order to solve the location, movement and accuracy limitations at once, we have developed a novice measurement device equipped with accelerometer sensor and gyroscope sensor for getting three-dimensional information of motion. Furthermore, Kalman filter was applied to the algorithm to improve accuracy. In addition, RF wireless communication was added for the user to conveniently check measured data in real time. Finally, the measurement method was improved by considering the movement by a reference point. An experiment was conducted to test the accuracy and reliability of the device by conducting a test-retest reliability test. Further modification will be conducted to used the device in various joints range of motion in clinical settings in the future.

An Embodied Approach to Testing Musical Empathy in Participants With an Autism Spectrum Disorder

We present an empirical and qualitative study testing musical empathic ability in participants with an autism spectrum disorder (ASD). Four experiments requiring an increasing level of empathy with music, from synchronization, and attuning to emotional empathy, were carried out, using kinematic devices for measuring embodied listening responses and a verbal emotion attribution task. Results suggest that people with ASD have a corporeal understanding of the affective features of music, since they are able to mirror structural and even affective features of the music into corporeal articulations. However, this corporeal understanding does not give them a straightforward access to the emotional content of the music. The participants with ASD seemed to rely on disembodied cognitive processes to attribute affects to music.

Limbs electrogoniometric study in a healthy trotting dog

Electrogoniometric studies are well known to provide reliable and accurate data to assess joint mobility and their angular velocity. Although many kinematic devices have been developed for gait ana...

Cyanidioschyzon merolae Genome. A Tool for Facilitating Comparable Studies on Organelle Biogenesis in Photosynthetic Eukaryotes

The ultrasmall unicellular red alga Cyanidioschyzon merolae lives in the extreme environment of acidic hot springs and is thought to retain primitive features of cellular and genome organization. We determined the 16.5-Mb nuclear genome sequence of C. merolae 10D as the first complete algal genome. BLASTs and annotation results showed that C. merolae has a mixed gene repertoire of plants and animals, also implying a relationship with prokaryotes, although its photosynthetic components were comparable to other phototrophs. The unicellular green alga Chlamydomonas reinhardtii has been used as a model system for molecular biology research on, for example, photosynthesis, motility, and sexual reproduction. Though both algae are unicellular, the genome size, number of organelles, and surface structures are remarkably different. Here, we report the characteristics of double membrane- and single membrane-bound organelles and their related genes in C. merolae and conduct comparative analyses of predicted protein sequences encoded by the genomes of C. merolae and C. reinhardtii. We examine the predicted proteins of both algae by reciprocal BLASTP analysis, KOG assignment, and gene annotation. The results suggest that most core biological functions are carried out by orthologous proteins that occur in comparable numbers. Although the fundamental gene organizations resembled each other, the genes for organization of chromatin, cytoskeletal components, and flagellar movement remarkably increased in C. reinhardtii. Molecular phylogenetic analyses suggested that the tubulin is close to plant tubulin rather than that of animals and fungi. These results reflect the increase in genome size, the acquisition of complicated cellular structures, and kinematic devices in C. reinhardtii.

Uncertainty propagation in calibration of parallel kinematic machines

This paper outlines in detail a method for determining the uncertainty present in the kinematic parameters (joint locations, initial strut lengths, and spindle location and orientation) for parallel kinematic devices after calibration. The uncertainty estimation method using Monte Carlo simulations was applied to a sequential method for determining the kinematic parameters of fully assembled Hexel Tornado 2000 (a 6–3 Stewart platform) milling machine. Results for the uncertainty present in the kinematic parameters of a Hexel Tornado 2000 milling machine after calibration using a SMX 4,000 laser tracker are shown.