scholarly journals Multi-Probe Measurement System Based on Single-Cut Transformation for Fast Testing of Linear Arrays

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1744
Author(s):  
Fernando Rodríguez Varela ◽  
Manuel José López Morales ◽  
Rubén Tena Sánchez ◽  
Alfonso Tomás Muriel Barrado ◽  
Elena de la Fuente González ◽  
...  

This paper introduces a near-field measurement system concept for the fast testing of linear arrays suited for mass production scenarios where a high number of nominally identical antennas needs to be measured. The proposed system can compute the radiation pattern, directivity and gain on the array plane, as well as the array complex feeding coefficients in a matter of seconds. The concept is based on a multi-probe antenna array arranged in a line which measures the near field of the antenna under test in its array plane. This linear measurement is postprocessed with state-of-the-art single-cut transformation techniques. To compensate the lack of full 3D information, a previous complete characterization of a “Gold Antenna” is performed. This antenna is nominally identical to the many ones that will be measured with the proposed system. Therefore, the data extracted from this full characterization can be used to complement the postprocessing steps of the single-cut measurements. An X-band 16-probe demonstrator of the proposed system is implemented and introduced in this paper, explaining all the details of its architecture and operation steps. Finally, some measurement results are given to compare the developed demonstrator with traditional anechoic measurements, and show the potential capabilities of the proposed concept to perform fast and reliable measurements.

2013 ◽  
Vol 300-301 ◽  
pp. 898-902 ◽  
Author(s):  
Zhi Wei Li ◽  
Tao Feng ◽  
Zhi Gang Huang ◽  
Bin Su ◽  
Ran Li ◽  
...  

According to the Near-Field Acoustic Holography (NAH) theory, we designed a measurement system, which was used to localize the noise source on five hologram surfaces of a industrial sewing machine. Moreover, we compared the localization results of the noise source on the front surface of the industrial sewing machine by NAH and sound intensity method respectively. The measurement results can provide a theoretical basis for controlling the noise of industrial sewing machine.


Author(s):  
Ye. Didenko ◽  
O. Stepanenko

One of the indicators of the effective use of artillery is the accuracy of the fire impact on the objects of enemy. The accuracy of the artillery is achieved by completing the implementation of all measures for the preparation of shooting and fire control. Main measures of ballistic preparation are to determine and take into account the summary deviation of the initial velocity. The existing procedure for determining the summary deviation of the initial velocity for the check (main) cannon of battery leads to accumulation of ballistic preparation errors. The supply of artillery units with means of determining the initial speed of the projectile is insufficient. Among the many known methods for measuring the initial velocity, not enough attention was paid to the methods of analyzing the processes that occur during a shot in the "charge-shell-barrel" system. Under the action of the pressure of the powder gases in the barrel channel and the forces of the interaction of the projectile with the barrel there are springy deformations in the radial direction. To measure springy deformations it is advisable to use strain gauge sensors. Monitoring of deformation in a radial direction by time can be used to determine the moment of passing a projectile past the strain gauge mounted on the outer surface of the barrel. In the case of springy deformations, the initial resistance of the sensor varies in proportion to its value. The speed of the shell (mine) in the barrel can be determined by time between pulses of signals obtained from strain gauges located at a known distance from each other. The simplicity of the proposed method for measuring the initial velocity of an artillery shell provides an opportunity for equipping each cannon (mortar) with autonomous means for measuring the initial velocity. With the simultaneous puting into action of automatic control systems can be automatically taking into account the measurement results. This will change the existing procedure for determining the total deviation of the initial velocity and improve the accuracy, timeliness and suddenness of the opening of artillery fire, which are components of its efficiency.


Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 640
Author(s):  
Yujia Tang ◽  
Zhangjian Li ◽  
Yaoyao Cui ◽  
Chen Yang ◽  
Jiabing Lv ◽  
...  

Ultrasound plane wave imaging technology has been applied to more clinical situations than ever before because of its rapid imaging speed and stable imaging quality. Most transducers used in plane wave imaging are linear arrays, but their structures limit the application of plane wave imaging technology in some special clinical situations, especially in the endoscopic environment. In the endoscopic environment, the size of the linear array transducer is strictly miniaturized, and the imaging range is also limited to the near field. Meanwhile, the near field of a micro linear array has serious mutual interferences between elements, which is against the imaging quality of near field. Therefore, we propose a new structure of a micro ultrasound linear array for plane wave imaging. In this paper, a theoretical comparison is given through sound field and imaging simulations. On the basis of primary work and laboratory technology, micro uniform and non-uniform linear arrays were made and experimented with the phantom setting. We selected appropriate evaluation parameters to verify the imaging results. Finally, we concluded that the micro non-uniform linear array eliminated the artifacts better than the micro uniform linear array without the additional use of signal processing methods, especially for target points in the near-field. We believe this study provides a possible solution for plane wave imaging in cramped environments like endoscopy.


2015 ◽  
Vol 105 (06) ◽  
pp. 377-383
Author(s):  
F. Klocke ◽  
R. Brocker ◽  
F. Vits ◽  
P. Mattfeld

Beim Vibrationsgleitschleifen wird der Werkstoffabtrag maßgeblich durch die vorherrschenden Kontaktkräfte zwischen dem Werkstück und den Schleifkörpern bestimmt. Dieser Fachartikel stellt ein Messsystem vor, mit dem die messtechnische Erfassung der Kontaktkräfte beim ungeführten Vibrationsgleitschleifen möglich ist. Ein Alleinstellungsmerkmal ist dabei die vollständig kabellose Ausführung des Messsystems. Somit wurden die Messergebnisse nicht durch Kabel beeinflusst, die üblicherweise für die Energieversorgung und Datenübertragung notwendig sind. Mithilfe dieses Messsystems wurde der Einfluss folgender Prozesseingangsgrößen systematisch untersucht: Schleifkörpergröße, Unwuchtmotordrehzahl, Versatzwinkel der Unwuchtgewichte sowie die Masse des unteren und oberen Unwuchtgewichts auf die Kontaktkräfte.   In vibratory finishing the material removal is influenced by the contact forces between work piece and media. In this paper a measurement system is presented which is able to measure contact forces between work piece and media in unguided vibratory finishing. The unique feature of the measurement system is its completely wireless construction so that the measurement results are not influenced by wires of the force sensor system including the electrical power supply and the data logging. By means of this measurement system, contact forces can be measured in unguided vibratory finishing processes for the first time. Furthermore, the influence of media size and adjustment of the unbalance motor like revolution speed, phase angle and mass distribution between the upper and the lower eccentric weight on the contact forces was investigated.


2020 ◽  
Vol 18 ◽  
pp. 17-22
Author(s):  
Fabian T. Faul ◽  
Hans-Jürgen Steiner ◽  
Thomas F. Eibert

Abstract. Near-field measurements are commonly performed in anechoic chambers which limits the flexibility of the measurements and requires high precision equipment to achieve exact results. In this contribution, we investigate a simple near-field measurement setup which does not use any sophisticated positioning system nor operates in a controlled environment. Instead, the probe antenna is moved by an operator person while the probe position is measured by a laser tracker. This implies that the measurement results will have a higher error level in comparison with antenna chamber measurements. However, excellent error levels are not always necessary, especially when it comes to on-site testing of the principle functionality of antennas. Measurement results are shown to illustrate the performance of the system.


2016 ◽  
Vol 52 (3) ◽  
pp. 1-4 ◽  
Author(s):  
A. Breard ◽  
F. Tavernier ◽  
Z. Li ◽  
L. Krahenbuhl

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