Strain-gauge sets for studying of power parametres of working bodies of soil-cultivating tool

Author(s):  
Andrey Dochkin
Keyword(s):  
2020 ◽  
Vol 17 ◽  
pp. 00010
Author(s):  
Maxim P. Erzamaev ◽  
Dmitry S. Sazonov ◽  
Alexander E. Afonin ◽  
Leila S. Kurmanova ◽  
Evgeny S. Nesterov

The article describes a strain gauge measuring system designed for measuring the traction resistance of tillage bodies and their combinations. Technical tools measure the traction resistance of the whole machine or one working body which is not an objective and reliable characteristics of combined tillage units. The design and principle of operation of the tensometric measuring system designed and manufactured by Samara State Agrarian University is described. It is used to determine the traction resistance of individual working bodies and their combinations. The results show that the measurement data on traction resistance are in compliance with the calculated values.


2020 ◽  
Vol 15 (7) ◽  
pp. 980-990 ◽  
Author(s):  
A.F. Rogachev ◽  
◽  
A.A. Karsakov ◽  
R.A. Kosulnikov ◽  
D.S. Gapich ◽  
...  

The efficiency of a field fleet unit is largely determined by the characteristics of the traction resistance of an agricultural machine, which are of a probabilistic nature and require experimental determination. The disadvantage of the known devices that provide measurements during the volumetric dynamometry of the working bodies of tillage machines and implements is the complexity of the design and a significant measurement error. To increase the accuracy of measurements of the dynamic loading of the working bodies of tillage machines, it is necessary to improve the measuring instruments that ensure the reduction of the error. The experimental determination of the loading of the working bodies requires the use of force sensors acting on the working bodies in different planes. Force transducers are mainly manufactured using strain gages, which are glued directly to parts with various cross-sections. To determine the efforts in the rods of the hydraulic linkage system of agricultural tractors use strain gauge fingers, which are cylinders with strain gages glued to them. It is shown that at equal distances l1 and l2 of the location of the sensors, the resulting signal does not depend on the l0 distance of force application on the axis of the finger. Typically, the calibration of force sensors is carried out on additional devices one by one under conditions as close as possible to real ones. The best calibration results will be when all sensors (strain gauge fingers) are installed in their original places and all sensors are calibrated at once. To do this, the intermediate plate is fixed with the help of tension fingers on the hydraulic tractor levers. Eyebolts are installed on the plate, to which a known force Р is applied three times and readings are taken from each of the strain gauge fingers. By solving the resulting system of equations, for example, using the Gauss method in the MathCad environment, all the calibration coefficients are simultaneously found. Additionally, a device is proposed, the kinematic diagram of which allows the use of a single measuring device, which simplifies the technology of measuring the force on the working body and increases its accuracy.


Phlebologie ◽  
2002 ◽  
Vol 31 (04) ◽  
pp. 85-90 ◽  
Author(s):  
H.-M. Häfner ◽  
H. Bablich ◽  
G. Rassner ◽  
M. Jünger ◽  
A. Steins

Zusammenfassung Ziel: Überprüfung der Korrelation der photooptischen Venenfunktionstests Lichtreflexionsrheographie (LRR), digitale Photoplethysmographie (DPPG) und der Quecksilberdehnungsstreifen- Plethysmographie (Hg-strain gauge) mit der Phlebodynamometrie (PDM). Methode: Die simultane Messung von LRR, DPPG, Hg-strain gauge und PDM wurde an 34 Patienten mit chronischer venöser Insuffizienz in den klinischen Stadien I bis III nach Widmer an insgesamt 39 Unterschenkeln vorgenommen. Die Messungen erfolgten während Dorsalextension des Fußes in sitzender und während Plantarflexion des Fußes in stehender Position. Als Parameter für die Ermittlung des Korrelationskoeffizienten wurden die Wiederauffüllzeiten t0 und t1/2 sowie die venöse Abpumpleistung ermittelt. Ergebnisse: Unabhängig von Körperposition und Anlage von Tourniquets erreichten die Korrelationen für alle Messverfahren und Parameter Werte zwischen r = 0,76 (t0 LRR) und r = 0,05 (Abpumpleistung DPPG automatische Auswertung). Eine gute Korrelation von t0 wurde in stehender Körperposition unabhängig von der Anlage der Tourniquets beim Hg-strain gauge (r = 0,49) und LRR (r = 0,51) erreicht. Diese Korrelation verbesserte sich in sitzender Körperposition. Die schlechteste Korrelation wurde bei der DPPG ermittelt (r = 0,25 in stehender, r = 0,51 in sitzender Position). Eine Verbesserung der Korrelation wurde beim DPPG durch die manuelle Auswertung der Kurven erreicht. Schlussfolgerung: Sowohl die Wahl des Untersuchungsverfahrens wie auch das gewählte Belastungsprogramm können erhebliche Auswirkungen auf die Korrelation mit der PDM haben. Unsere Ergebnisse zeigen, dass bei der Bewertung der Wiederauffüllzeiten t0 und t1/2 der Hg-strain gauge und die LRR die höchste Korrelation bei Dorsalextension in sitzender Körperposition mit der PDM aufweisen.


1982 ◽  
Vol 47 (02) ◽  
pp. 141-144 ◽  
Author(s):  
H Bounameaux ◽  
B Krähenbühl ◽  
S Vukanovic

SummaryDoppler ultrasound flow examination, strain gauge plethysmography and contrast venography were performed in 160 lower limbs of 80 in-patients. Deep vein thrombosis (DVT) was suspected in 87 limbs. Using measurement of venous stop-flow pressure, the Doppler method had an overall sensitivity of 83%. By combined use of Doppler and Plethysmography, sensitivity was increased to 96%. Specificity was 62% and 51%, respectively. With a positive and a negative predictive value of 80% and 73%, respectively, the combination of both non-invasive methods cannot reliably replace venography in the diagnosis of DTV, although all (40/40) thromboses proximal to or involving the popliteal segment were detected by either Doppler and Plethysmography or both.After exclusion of 14 patients (18%) suffering from conditions known to alter the results of these non-invasive methods, the positive predictive value of abnormal findings in both Doppler and Plethysmography was increased to 94% for suspected limbs, whilst negative predictive value of both negative Doppler and Plethysmography was 90%, allowing the avoidance of venography in these patients.


2019 ◽  
Vol 139 (4) ◽  
pp. 63-68
Author(s):  
Hiroshi Nakano ◽  
Masahiro Matsumoto ◽  
Yasuo Onose ◽  
Kazuhiro Ohta

2017 ◽  
Vol 48 (2) ◽  
pp. 187-197 ◽  
Author(s):  
Valerii Semyonovich Volobuyev ◽  
Anton Roaldovich Gorbushin ◽  
Iraida Alekseevna Sudakova ◽  
V. I. Tikhomirov

2019 ◽  
pp. 82-85
Author(s):  
Pavel Ivanovich Pavlov ◽  
Viktor Vladislavovich Korsak ◽  
Aleksandr Olegovich Vezirov ◽  
Dmitriy Vadimovich Mukhin

The regression equations and graphical dependencies are obtained, which describe the influence of design and operating parameters on the drive power of the working bodies. The value of the design and operating parameters in which the power required to drive the working bodies, will have a minimum value  are experimentally determined.


Author(s):  
D. N. Radnaev ◽  
Yu. А. Sergeev ◽  
А. А. Abiduev ◽  
S. V. Petunov

Currently, agricultural science and practice has a large amount of experimental data that need to be taken into account in the development of new technological processes and working bodies. Therefore, there is a need to design technical processes in order to identify their effectiveness. In this regard, the use of methods of synthesis of technological processes based on the characteristics of tillage, seeding and production system of the economy, in which it is necessary to implement the projected process. In the General statement of the problem, the design of technological processes is one of the complex problems with the following characteristic feature: lack of knowledge about the methods of designing technological processes, suitable for system - structural modeling and algorithmization of design processes. To overcome this incompleteness, a systematic approach is needed. The system approach proceeds from the fact that the specificity of complex objects and processes is not limited to the features of its constituent parts and elements, but lies in the nature of relationships and relationships between them. In this paper, the design methodology is based on the formulated fundamental assumptions and principles of the whole system of more specific statements, revealing the structure and content of design operations, the synthesis of the choice of solutions. The principles of technological compatibility and emergence suitable for system-structural analysis of complex technical means and technological processes, consisting of statements having a hierarchical structure, where the degree of detail of the goals from level to level increases, and the approval of the last level determines the direction of the search for the optimal solution to the problem.


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