Kinematic Device Research Articles

Technical note: assessing GPS sensor accuracy using real-time kinematic device for livestock tracking.

The technical aspects of global positioning system (GPS) sensors have been improved substantially over the years, making them valuable and popular tools for livestock tracking. Using GPS sensors allows producers and researchers to locate grazing livestock, monitor their behavior and distribution, and gather referencing information about the health status of the animals and pastures. However, interpreting the behavior of grazing livestock, such as cattle, from GPS data can be difficult due to positioning inaccuracies. Without knowing the positioning accuracy range of GPS sensors, achieving high-level confidence in determining grazing densities and identifying abnormal livestock movement patterns is challenging. In this study, the positioning accuracy of 3 different types of commercial GPS sensors was assessed using a survey-grade real-time kinematics (RTK) device. We outlined the procedures and essential equations and compared the recorded locations from the GPS sensors with reference locations collected from the RTK device. The results demonstrated statistically significant differences (P < 0.05) in positioning accuracy between different types of GPS sensors. The circular error probable (CEP) at 95% probability levels (CEP95) of the 3 sensors ranged from 2.46 to 11.06 m. This accuracy varied among individual sensors within the same brand and across different brands, which underscores the importance of evaluating the positioning accuracy of GPS sensors in livestock tracking. This study provides significant insights for animal scientists, ecologists, and livestock producers engaged in GPS sensor-related research and practices.

A Direct-drive Rotary-Linear Machine with Dual-PM Flux Modulation for 2-DOF Kinematic Device

A Direct-drive Rotary-Linear Machine with Dual-PM Flux Modulation for 2-DOF Kinematic Device

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.

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.

Combining Image Processing Techniques and Mobile Sensor Information for Marker-less Augmented Reality Based Reconstruction

Marker-less Augmented Reality(AR) based recon- struction using mobile devices, is a near impossible task. When considering vision based tracking approaches, it is due to the lack of processing power in mobile devices and when considering mobile sensor based tracking approaches, it is due to the lack of accuracy in mobile Global Positioning System(GPS). In order to address this problem this research presents a novel approach which combines image processing techniques and mobile sensor information which can be used to perform precise position localization in order to perform augmented reality based reconstruction using mobile devices. The core of this proposed methodology is tightly bound with the image processing technique which is used to identify the object scale in a given image, which is taken from the user’s mobile device. Use of mobile sensor information was to classify the most optimal locations for a given particular user location. This proposed methodology has been evaluated against the results obtained using 10cm accurate Real-Time Kinematic(RTK) device and against the results obtained using only the Assisted Global Positioning System(A-GPS) chips in mobile devices. Though this proposed methodology require more processing time than A-GPS chips, the accuracy level of this proposed methodology outperforms that of A-GPS chips and the results of the experiments carried out further convince that this proposed methodology facilitates improving the accuracy of position local- ization for augmented reality based reconstruction using mobile devices under certain limitations.

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.

A Sensitivity Analysis Approach for Assessing the Effect of Design Parameters in Reducing Seismic Demand of Base-Isolated Storage Racks

The most used global sensitivity analysis (GSA) method is based on variance. This is performed using Monte Carlo Sampling (MCS) or Latin Hypercube Sampling (LHS). It requires a large sample to obtain accurate estimates. Density-based methods, such as the GSA PAWN, have been developed to reduce the sample size without compromising the result. PAWN is simpler than other methods because it uses cumulative density functions (CDF) instead of probability density. This method has been widely used in areas such as environmental engineering with very good results, reducing computation time. However, its use in structural engineering is incipient. The PAWN method was used to classify the design variables of the isolation system in relation to their sensitivity, and in relation to the seismic response of industrial storage racks. The above was analyzed in terms of the effectiveness of each variable to reduce the seismic demand using a novel base isolation kinematic device (BIKD). Racks with different combinations of their structural parameters such as the number of storage levels, the height between them, and isolation period, among others, were studied. The dimensions of the racks were chosen to match those that would later be experimentally tested on shaking table. An earthquake whose response spectrum matched the design spectrum of current Chilean regulations, was considered as seismic forcing. The maximum base shear load, the displacement of the top level of storage and the floor drift were considered as target responses to be studied. Fixed base racks (FBR), as reference, and base-isolated racks (BIR) were analyzed. The results showed the effectiveness of using the BIKD system in reducing all three-target responses up to one order of magnitude. Additionally, it was determined that the parameters that have the greatest influence on the response correspond to the number of storage levels and the height between them, both for FBR and BIR.

A study of the kinematic characteristic of a coupling device between the buffer system and the flexible pipe of a deep-seabed mining system

This paper concerns the kinematic characteristics of a coupling device in a deep-seabed mining system. This coupling device connects the buffer system and the flexible pipe. The motion of the buffer system, flexible pipe and mining robot are affected by the coupling device. So the coupling device should be considered as a major factor when this device is designed. Therefore, we find a stable kinematic device, and apply it to the design coupling device through this study. The kinematic characteristics of the coupling device are analyzed by multi-body dynamics simulation method, and finite element method. The dynamic analysis model was built in the commercial software DAFUL. The Fluid Structure Interaction (FSI) method is applied to build the deep-seabed environment. Hydrodynamic force and moment are applied in the dynamic model for the FSI method. The loads and deformation of flexible pipe are estimated for analysis results of the kinematic characteristics.

Design and analysis of a head-mounted parallel kinematic device for skull surgery

Precision skull surgery requires specialized instrumentation to satisfy demanding requirements in cochlear array implantation, deep brain stimulation electrode placement, and related applications. A miniaturized reconfigurable parallel kinematic mechanism which can be directly mounted on a patient's skull was designed, built, and tested for precision skull surgery. A Stewart-Gough platform is attached to a patient's skull so no optical tracking affecting the overall accuracy in keyhole surgery is required. Six bone anchors comprising the mechanism base joints are implanted at positions with sufficient skull thickness. Since no fixation frame is required, intervention planning flexibility is increased. The centers of the spherical shaped bone anchors can be localized accurately in the image space. An implicit registration to the physical space is performed by assembling the kinematics. Registration error is minimized compared to common optical tracker-based approaches. Due to the reconfigurable mechanism, an optimization of the hexapod's configuration is needed to maximize accuracy and mechanical stability during the incision. Mathematical simulation was conducted to estimate system performance. Simulation results revealed significant improvement in accuracy and stability when exploiting the redundant degrees of freedom and the implemented reconfigurability. Inaccurate localization of base points in the image data set was identified as the main source of error. A first prototype with passive prismatic actuators, i.e. micrometer calipers, was successfully built. A head-mounted parallel kinematic device for high precision skull surgery was developed that provides submillimetric accuracy in straight-line incisions. The system offers enhanced flexibility due to the absence of a rigid fixation frame.

Patellofemoral pressure after TKA in vitro: highly conforming vs. posterior stabilized inlays

When highly conforming polyethylene inlays were introduced into total knee arthroplasty (TKA), they were characterized as adding anteroposterior stability to the reconstructed knee. The aim of this study was to examine the patellofemoral pressure with the designs of a highly conforming and a posterior stabilized inlay. The patellofemoral pressure depends among other factors on the anteroposterior stability of the knee joint. Eight fresh frozen human knee specimens underwent testing in a kinematic device. Knee motion was driven by a hydraulic cylinder at an extension moment of 31 Nm. The patellofemoral contact pressure was measured using a pressure sensitive film (Tekscan((R)), Inc., Boston, USA). First, this was assessed after implantation of a cruciate retaining (CR) TKA with a highly conforming polyethylene insert before and after resection of the posterior cruciate ligament. After that, the same measurements were performed with a similar posterior stabilized prosthesis. Patellofemoral contact pressures in the CR prosthesis using the highly conforming inlay were not significantly different before and after resection of the posterior cruciate ligament. However, after implantation of a posterior stabilized prosthesis peak pressure was significantly lower [Mean: 6.12, (SD 2.37) MPa] in comparison to the highly conforming type [7.12, (SD 2.53) MPa, P < 0.01] at a preserved posterior cruciate ligament. Further to that, the mean contact pressure turned out to be lower with the posterior stabilized design (P < 0.006). The results of this study suggest that a posterior stabilized prosthesis design reduces the patellofemoral peak and mean pressure in comparison with a high conforming design. The better reproducible femoral rollback with a posterior stabilized model at a tibial ventral shift could serve as a possible explanation.

Quadriceps force in relation of intrinsic anteroposterior stability of TKA design

Decreased quadriceps strength and fatigue is suspected to be one of the contributing factors for anterior knee pain and malfunction after total knee arthroplasty (TKA). The purpose of this in vitro study was to investigate the amount of quadriceps force required to extend the knee isokinetically after TKA in dependence of different prosthesis designs and the state of the posterior cruciate ligament (PCL). Eight fresh frozen human knee specimens underwent testing in a kinematic device simulating an isokinetic knee extension cycle from 120° of flexion to full extension. The quadriceps force was measured after implantation of a cruciate retaining (CR) TKA (Genesis II, Smith&Nephew, Memphis, TN, USA) applying a conventional CR (11 mm) and a highly conforming (deep dished, DD) polyethylene (PE) inlay consecutively before and after resection of the PCL. Finally, tests were repeated with a posterior-stabilized (PS) design. Simulating a physiological knee extension, no significant differences in the average quadriceps force were detected between the cruciate preserving inlays (CR 1,146.57 ± 88.04 N, DD 1,150.19 ± 97.54 N, P = 0.86) as long as the PCL was intact. After resection of the PCL, the required quadriceps force increased significantly for both designs (CR 1,203.17 ± 91.51 N, P < 0.01 and DD 1,191.88 ± 80.07 N, P < 0.03). After implantation of the posterior stabilized femoral component quad force decreased to its initial levels with forces significantly lower compared to the PCL deficient knees provided with a CR or DD (PS 1,130.91 ± 107.88 N, P < 0.01) inlay. With a deficient PCL there were no statistical differences for the DD design in comparison with CR in mean quad forces (CR 1,203.17 ± 91.51 N vs. DD 1,191.88 ± 80.07 N, P = 0.50) nor in peak forces (CR 1,729.44 ± 161.86 N, DD 1,688.66 ± 123.18 N, P = 0.17). At intact PCL peak quad forces and mean forces beyond 70° of flexion could be shown to be significantly lower with a PS TKA design in comparison with cruciate preserving designs such as CR and DD. In the PCL deficient knee quad forces with a highly conforming implant (DD) and CR were significantly higher than with a PS TKA. The use of PS implants in all PCL deficient knees seems to be advisable

Importance of Upper-Limb Inertia in Calculating Concentric Bench Press Force

The purpose of this study was to investigate the influence of upper-limb inertia on the force-velocity relationship and maximal power during concentric bench press exercise. Reference peak force values (Fpeakp) measured with a force plate positioned below the bench were compared to those measured simultaneously with a kinematic device fixed on the barbell by taking (Fpeakt) or not taking (Fpeakb) upper-limb inertia into account. Thirteen men (27.8 +/- 4.1 years, 184.6 +/- 5.5 cm, 99.5 +/- 18.6 kg) performed all-out concentric bench press exercise against 8 loads ranging between 7 and 74 kg. The results showed that for each load, Fpeakb was significantly less than Fpeakp (P < 0.0001), whereas no significant difference was found between Fpeakp and Fpeakt. The values of maximal force (F0), maximal velocity (V0), optimal velocity (Vopt), and maximal power (Pmax), extrapolated from the force- and power-velocity relationships determined with the kinematic device, were significantly underestimated when upper-limb inertia was ignored. The results underline the importance of taking account of the total inertia of the moving system to ensure precise evaluation of upper-limb muscular characteristics in all-out concentric bench press exercise with a kinematic device. A major application of this study would be to develop precise upper-limb muscular characteristic evaluation in laboratory and field conditions by using a simple and cheap kinematic device.

Validity and Reliability of a Kinematic Device for Measuring the Force Developed during Squatting

This study determined the validity and reliability of the kinematic device developed by Bosco et al. (1995) by comparing its peak force, peak velocity, and peak power measurements to data obtained simultaneously with a force platform placed under the subject’s feet. Fifteen international downhill skiers performed maximal half-squats on a guided barbell with masses of 60–180 kg. The coefficient of correlation (r) between the two peak forces (r = 0.85–0.95, p &lt; .001), the two peak velocities (r = 0.74–0.91, p &lt; .001), and the two peak powers (r = 0.85–0.95, p &lt; .001) indicated that the kinematic device measurements were valid. The trial-to-trial reliability of half-squat exercises measured by the kinematic device gave an intraclass coefficient of correlation (CR) of: 0.70-0.90 for peak force, 0.62-0.90 for peak velocity, and 0.57-0.91 for peak power. There were no statistical differences between the two trials. The standard error of the means (SEM%) was less than 5% for peak force, less than 4% for peak velocity, and less than 7% for power. The high CR and low SEM% indicate that the kinematic device is reliable. The movement recorded by the kinematic device accurately described the action measured by the force platform.

The “Blondelion” a kinematic device which indicates the performance of a polyphase synchronous generator or motor

The “Blondelion” a kinematic device which indicates the performance of a polyphase synchronous generator or motor

The “Heavisidion” a computing kinematic device for long transmission lines

Subject of the Paper. — A kinematic computing device is described which can be set to represent vectorially the voltage and the current at any point of a long transmission line with uniformly distributed properties and with a given load. The device has been named after Oliver Heaviside who was among the first to establish and to solve the fundamental differential equations of such a line. The parts of the device are made to assume at will different positions corresponding to different points on the line. The constants of a line to be represented by the device are adjustable at will, and a complete set of performance curves of a given transmission line can be obtained. Conversely, by a few simple trials, the best constants of a line and the necessary kv-a. of a synchronous condenser may be found, to give the required performance characteristics. The current, the voltage, and the power factor (or the phase angle) can be read off directly on the device for any desired point of the line, including the generator and the load end. Results of computations are shown for two transmission lines, 1000 and 300 miles long, values having been obtained in the usual tedious way by means of hyperbolic functions of a complex variable, and also read off directly on the Heavisidion. The agreement is as good as could be desired, showing that the device is reliable and that a considerable saving in time is possible with it. The device consists mainly of steel and celluloid bars, proportional dividers, parallel double tongs, and other simple kinematic linkages. Two sharp-edged wheels are used, similar to those used in planimeters. The parts are so combined as to satisfy the familiar exponential vectorial expressions for the sinusoidal voltage and the current, the independent variable being the distance from one of the ends of the line.

The ``Blondelion'' A Kinematic Device which Indicates the Performance of a Polyphase Synchronous Generator or Motor

The ``Blondelion'' A Kinematic Device which Indicates the Performance of a Polyphase Synchronous Generator or Motor

The “Indumor”: A kinematic device which indicates the performance of a polyphase induction machine

A kinematic device is described and illustrated which represents the vector diagram of a polyphase induction machine. The parts are made to assume at will different positions corresponding to different loads of an induction motor or generator. The primary and the secondary constants, the magnetizing current, and the core loss, are also adjustable at will. The device permits the visualization of the performance of an induction machine and can be used for a study of a given machine or for a selection of the constants to give the desired performance characteristics of a new machine. The input, output, torque, speed, power factor, etc., can be read off on the device as in an actual brake test. The kinematic connections consist mainly of generalized proportional dividers and of parallel tongs, so combined as to satisfy a system of simultaneous vectorial equations which represent the properties of the machine. Further applications of the device to polyphase commutator motors are suggested.

The ``Indumor'' A Kinematic Device which Indicates the Performance of a Polyphase Induction Machine

A kinematic device is described and illustrated which represents the vector diagram of a polyphase induction machine. The parts are made to assume at will different positions corresponding to different loads of an induction motor or generator. The primary and the secondary constants, the magnetizing current, and the core loss, are also adjustable at will. The device permits the visualization of the performance of an induction machine and can be used for a study of a given machine or for a selection of the constants to give the desired performance characteristics of a new machine. The input, output, torque, speed, power factor, etc., can be read off on the device as in an actual brake test. The kinematic connections consist mainly of generalized proportional dividers and of parallel tongs, so combined as to satisfy a system of simultaneous vectorial equations which represent the properties of the machine. Further applications of the device to polyphase commutator motors are suggested.

The secomor a kinematic device which imitates the performance of a series-wound polyphase commutator motor

The device consists of four bars of adjustable useful length and with adjustable angles. These bars can be set in a combination to represent the vector diagram of voltages in a motor with any desired constants. By moving the bars to vary the load, complete performance characteristics of the motor can be obtained, including the speed, the torque, the power factor, etc. An additional device called the impedometer permits to take into account the impedance drop in the machine. An adjustable saturation curve made of soft wire is used in connection with the secomor, to enable one to investigate the effect of saturation. A brief graphical theory of the motor precedes the description of the secomor to make its action understandable.