MODELING OF STATIC CHARACTERISTICS OF PNEUMATIC STRAIN GAUGE TRANSDUCER

2019 ◽  
pp. 48-52
Author(s):  
A. P. Vasytenko ◽  
A. Yu. Tarakhovskiy

Measuring instruments that implement the pneumatic principle of measurement, have a number of significant advantages: small dimensions of the measuring equipment, allowing to produce multiparameter control in a limited size of the working area, insensitivity to vibration, simplicity of design and reliability. The disadvantage of pneumatic converters is a discrete output electrical signal, which does not allow the processing of measurement results. In this regard, it seems appropriate to investigate the pneumatic-electric Converter, which includes a jet pneumatic and differential strain gauges, which allows to obtain an analog electrical signal at the output. The article describes the design and principle of operation pneumoenteritis Converter to control the diameter of the part. Pneumotensometric Converter converts the change in the diameter of the part in the movement of the nozzle, which causes a change in the force of the air jet on the beam, its deformation and, accordingly, a change in the resistance of he strain gauge. An expression describing the stoic characteristic of the transducer and allowing to determine the force of the air jet impact on the load cell from the gap between the nozzle and the beam, the air pressure and the nozzle diameter is given. The results of modeling the static characteristics of the Converter at different combinations of design parameters are given, the values of straight sections of characteristics and sensitivity are determined, their comparative evaluation is given.

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.


2017 ◽  
Vol 24 (1) ◽  
pp. 73-79
Author(s):  
Md. Moinul Islam ◽  
Mohammad Tariqul Islam ◽  
Mohammad Rashed Iqbal Faruque ◽  
Rabah W. Aldhaheri ◽  
Md. Samsuzzaman

AbstractA compact ultra-wideband (UWB) antenna is presented in this paper with a partial ground plane on epoxy woven glass material. The study is discussed to comprehend the effects of various design parameters with explicit parametric analyses. The overall antenna dimension is 0.22×0.26×0.016 λ. A prototype is made on epoxide woven glass fabric dielectric material of 1.6 mm thickness. The measured results point out that the reported antenna belongs to a wide bandwidth comprehending from 3 GHz to more than 11 GHz with VSWR<2. It has a peak gain of 5.52 dBi, where 3.98 dBi is the average gain. Nearly omnidirectional radiation patterns are observed within the operating frequency bands. A good term exists between simulation and measurement results, which lead the reported antenna to be an appropriate candidate for UWB applications.


2021 ◽  
Vol 31 (1) ◽  
pp. 127-142
Author(s):  
Vyacheslav F. Fedorenko ◽  
Vitaly E. Tarkivskiy ◽  
Nikolay P. Mishurov ◽  
Nikolay V. Trubitsyn

Introduction. When carrying out an energy assessment of agricultural machines and traction tests of tractors, the most important indicator is the value of the tractive effort. The existing methods for determining the tractive effort of tractors imply the use of specialized measuring instruments, such as strain gauges and devices for processing and displaying information. The accuracy of determining the tractive effort is significantly influenced by the physical and mechanical properties of soil. To process the useful signal during the measurement of tractive effort, the data stream of the strain gauge sensor must be subjected to additional digital filtering taking into account the operating conditions of the agricultural unit. Materials and Methods. The functions of changing the tractive effort obtained on the K-744R2 tractor in various gears have been analyzed. An algorithm for digital processing of the signal of a strain gauge force meter based on a median filter has been developed that makes it possible to increase the measurement accuracy. The advantage of the proposed method is the ability to cut off sharp short-term impulse noise and sharp fluctuations in the amplitude of the measured value. Results. A method for determining the amount of tractive effort using median signal processing has been proposed. A device for determining the tractive effort during testing of agricultural tractors and units has been developed. The choice of the main components of the device for determining the magnitude of the tractive effort has been substantiated. As a result of the research, a device for measuring and digital processing of the signal of a force meter based on a microcontroller and specialized software for processing initial data in real time was designed and manufactured. Discussion and Conclusion. The developed method makes it possible to exclude the negative effect of impulse noise arising in the process of measuring the tractive effort of the tractor. The proposed device for measuring the tractive effort of tractors is compatible at the level of the exchange protocol with existing devices, has a high speed of operation in real time, multi-channel operation.


Author(s):  
J Wang ◽  
A Moridi ◽  
P Mathew

An investigation of the micro-grooving performance of abrasive air jet (AAJ) on quartz crystals is presented and discussed. An experimental study was carried out first to understand the effect of process parameters on the major grooving performance measures such as groove depth, groove width, kerf taper, and surface roughness. Plausible trends for these grooving performance measures with respect to the various process variables, such as air pressure, nozzle traverse speed, jet impact angle, and abrasive mass flowrate, are discussed. It is found that AAJ is an effective technology for micromachining of quartz crystals and the grooving performance can be improved or optimized by selecting the process parameters properly. Predictive models are then developed for quantitatively estimating the micro-grooving performance. The models are finally verified by an experiment. It shows that the model predictions are in good agreement with the experimental results under the corresponding conditions.


Author(s):  
Fusheng Wang ◽  
Gang Bao

The new type externally pressurized spherical air bearings used mass properties measuring instruments are studied which are particularly recommended for determining mass properties of rockets, satellites and ballistic objects. The air bearings are the key component of the mass properties measuring instruments. In order to provide some theoretical guideline for the structure design of the new type externally pressurized spherical air bearings, this paper analyzes static characteristics and the factors affecting the static characteristics of the new type air bearings. A finite volume method is adopted to discretize the three-dimensional steady-state compressible Navier-Stokes equations, and a modified SIMPLE algorithm for compressible fluid is applied to solve the discretized governing equations. The pressure field and velocity field of the air bearings are obtained, from which the carrying capacity, static stiffness and mass flow of the air bearings can be derived, and the factors and rules affecting the static characteristics are analyzed. The calculation method proposed in this paper fits well the general principle, which can be extended to the characteristics analysis of other air bearings.


1967 ◽  
Vol 35 (5) ◽  
pp. 415-418
Author(s):  
B. S. Gill ◽  
V. J. Modi ◽  
K. L. Tong

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