scholarly journals Kinematic Analysis and Performance Test of a 6-DOF Parallel Platform with Dense Ball Shafting as a Revolute Joint

2021 ◽  
Vol 11 (14) ◽  
pp. 6268
Author(s):  
Hasiaoqier Han ◽  
Yang Zhang ◽  
Hui Zhang ◽  
Chunyang Han ◽  
Ang Li ◽  
...  
Keyword(s):  
Performance Test ◽  
Performance Testing ◽  
Parameter Method ◽  
Optical Telescope ◽  
Working Space ◽  
Shaft System ◽  
Numerical Iteration ◽  
Parallel Platform ◽  
And Performance ◽  
Adjustment System

To meet the special requirements of the third mirror adjustment system for an optical telescope, a 6-P-RR-R-RR parallel platform using offset RR-joints is designed with high precision, a large load-to-size ratio and high stiffness. In order to improve the adjustment accuracy and the stiffness of the whole mechanism, each rotating joint in the subchain is designed as a zero-gap bead shaft system. When compared with a traditional Hooke joint, the offset RR joint has certain characteristics, including large carrying capacity and easy processing and adjustment, that effectively reduce the risk of interference with the joint during rotation and increase the working space of the entire machine. Because of the additional variables introduced by the offset joints, the kinematics problem becomes much more complicated. Regarding the P-RRRRR series subchain, the kinematics model is established using the Denavit–Hartenberg parameter method and then solved by the numerical iteration method. The stiffness of the parallel platform is analyzed and tested, including static and fundamental frequency. Motion performance testing of the parallel platform is performed.

Kinematics analysis and performance testing of 6-RR-RP-RR parallel platform with offset RR-hinges based on Denavit-Hartenberg parameter method

2021 ◽  
pp. 095440622097843
Author(s):  
Yang Zhang ◽  
Ha-si-ao-qi-er Han ◽  
Zhen-bang Xu ◽  
Chun-yang Han ◽  
Yang Yu ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Dynamic Stiffness ◽  
Performance Testing ◽  
Simulation Method ◽  
Parameter Method ◽  
Parallel Mechanisms ◽  
Static Stiffness ◽  
Leg Length ◽  
Parallel Platform ◽  
Adjustment System

A six degrees-of-freedom parallel platform in a 6-RR-RP-RR configuration with high accuracy, high stiffness and a large working stroke is studied for application to the sub-mirror adjustment system of a large-aperture telescope. To meet the performance requirements, the parallel platform adopts a self-centering and well-designed offset universal hinge. The two hinge axes of the offset hinge do not intersect but have a specific offset in space, which makes the kinematics more complex than that with a common universal hinge. Therefore, to solve this complex kinematics problem, this paper innovatively introduces the Denavit–Hartenberg (D-H) parameter method that is used for series mechanisms. The method has a simple modeling process, strong applicability and continuity, providing a new tool for the analysis and application of the parallel mechanisms. A kinematics model of the parallel platform can be constructed and solved using a numerical iteration method. The accuracy of the numerical kinematics solution is verified using a co-simulation method. This paper analyses the passive derivative motion and the leg length error is compensated. Finally, test studies of the motion resolution, the repetitive positioning accuracy, the motion stroke, the static stiffness of the legs, and the static stiffness and dynamic stiffness of the entire machine were also carried out to verify the platform’s performance.

Study on Water-Lubricated Graphite Sliding Bearing Performance Test

2013 ◽  
Vol 655-657 ◽  
pp. 636-639
Author(s):  
Yang Yu ◽  
Wei Zhao
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Performance Test ◽  
Performance Testing ◽  
High Wear Resistance ◽  
Widespread Application ◽  
Sliding Bearing ◽  
Temperature Resistance ◽  
Shaft System ◽  
Bearing Friction

Water-lubricated graphite bearing has gradually obtained the widespread application, with its high wear resistance, high temperature resistance and self lubricating, This paper designed the water-lubricated graphite sliding bearing performance testing platform and studied the factors that could affect bearing friction wear rate and the vibration of bearing, such as load, speed and running time. The final results show that the water-lubricated graphite sliding bearing can basically meet the requirements of the blower shaft system.

scholarly journals Rancang Bangun dan Uji Kinerja Mesin Pembersihan dan Pengayakan Tipe-Grizzly Untuk Beras

2021 ◽  
Vol 14 (2) ◽  
pp. 65-75
Author(s):  
Aprilia Dila Wardiningrum ◽  
Agus Dharmawan ◽  
Soni Sisbudi Harsono ◽  
Siswoyo Soekarno
Keyword(s):  
Performance Test ◽  
Performance Testing ◽  
Work Capacity ◽  
Airflow Rate ◽  
Optimal Separation ◽  
And Performance ◽  
Main Components ◽  
Data Collections ◽  
Rotational Slip ◽  
Machine Work

Abstrak. Penelitian ini bertujuan untuk mengembangkan mesin pembersih dan pengayak tipe grizzly untuk beras sekaligus menguji kinerja mesin. Penelitian terdiri atas perancangan, perakitan, dan evaluasi kinerja mesin. Mesin yang dikembangkan memiliki 6 (enam) komponen utama, yaitu sumber dan transmisi tenaga putar, lubang pemasukan, unit pembersih beras, unit pengayak beras, lubang pengeluaran, dan kerangka mesin. Penelitian dilakukan menggunakan 3 (tiga) percobaan putaran, L (lambat), S (sedang), dan C (cepat) untuk mendapatkan data dari parameter pengukuran seperti kapasitas kerja, kecepatan putar mesin, laju isapan udara pada unit pembersih, slip putaran puli, dan persentase kehilangan bahan. Pada percobaan putaran L-S-C, yaitu 1654, 1817, dan 1979 rpm, menghasilkan laju isapan udara adalah 7,04, 7,79, dan 8,50 m/s. Slip putaran puli terjadi pada pulli 4 dengan nilai 3,27% tanpa sampal dan 1,70% dengan sampel; puli ini bertugas untuk menggetarkan ayakan grizzly 10-mesh. Kapasitas kerja pada 3 percobaan putaran (L-S-C) berturut-turut adalah 78,5, 81,6 dan 146,7 kg/jam. Pemisahan optimal dedak terjadi para percobaan putaran C sendangkan pemisahan menir terjadi pada percobaan L. Persentase kehilangan bahan tertinggi terjadi selama terjadi penurunan kecepatan putar yang mengakibatkan penurunan efektivitas kerja mesin.Design and Performance Test of Cleaning and Gryzzly-Type Sieving Machine for Rice Abstract. This research aimed to develop and a rice cleaning and grizzly-type sieving machine which also evaluates its performance. It consisted of designing, assembling, and performance evaluating of the machine. The desired machine was developed in six main components, i.e., power source, hopper, rice cleaner, rice siever, outlets, and machine frame. The research used three rotational speed treatments (Slow-Middle-Fast or L-S-C rotations) for data collections, whereas the parameters of performance testing consisted of work capacity, engine rotation speed, airflow rate, pulley rotational slip, and grain loss percentage. Engine rotation speeds at L-S-C treatments are 1654, 1817, and 1979 rpm and resulted in 7.04, 7.79, and 8.50 m/s, respectively, for airflow rates produced by the suction from a blower. The most significant rotational slip is occurred at Pulley-4 resulted in 3.27% (operating without samples) and 1.70% (operating with samples); this pulley transmitted rotational power to vibrate the 10-mesh grizzly sieve. The work capacities at L-S-C rotational treatments were 78.5, 81.6, and 146.7 kg/h, respectively. The optimal separation of brans was at C-rotational treatment, while the optimal separation of groats was at L-rotational treatment. The high percentage of grain loss occurred along with a reduction in speed that made the machine work ineffectively.

scholarly journals Automatic Detection of Granuloma Necrosis in Pulmonary Tuberculosis Using a Two-Phase Algorithm: 2D-TB

2019 ◽  
Vol 7 (12) ◽  
pp. 661
Author(s):  
Pelin Kus ◽  
Metin N. Gurcan ◽  
Gillian Beamer
Keyword(s):  
Pulmonary Tuberculosis ◽  
Performance Test ◽  
Phase 1 ◽  
Performance Testing ◽  
Two Phase ◽  
Background Elimination ◽  
Expert Pathologist ◽  
Histopathological Images ◽  
And Performance ◽  
Automated Algorithms

Granuloma necrosis occurs in hosts susceptible to pathogenic mycobacteria and is a diagnostic visual feature of pulmonary tuberculosis (TB) in humans and in super-susceptible Diversity Outbred (DO) mice infected with Mycobacterium tuberculosis. Currently, no published automated algorithms can detect granuloma necrosis in pulmonary TB. However, such a method could reduce variability, and transform visual patterns into quantitative data for statistical and machine learning analyses. Here, we used histopathological images from super-susceptible DO mice to train, validate, and performance test an algorithm to detect regions of cell-poor necrosis. The algorithm, named 2D-TB, works on 2-dimensional histopathological images in 2 phases. In phase 1, granulomas are detected following background elimination. In phase 2, 2D-TB searches within granulomas for regions of cell-poor necrosis. We used 8 lung sections from 8 different super-susceptible DO mice for training and 10-fold cross validation. We used 13 new lung sections from 10 different super-susceptible DO mice for performance testing. 2D-TB reached 100.0% sensitivity and 91.8% positive prediction value. Compared to an expert pathologist, agreement was 95.5% and there was a statistically significant positive correlation for area detected by 2D-TB and the pathologist. These results show the development, validation, and accurate performance of 2D-TB to detect granuloma necrosis.

scholarly journals MODIFIKASI DAN UJI KINERJA UNIT PENYOSOH PADA MESIN PENYOSOH BIJI HANJELI (MPBH-0219)

2020 ◽  
Vol 9 (2) ◽  
pp. 71
Author(s):  
Wahyu K Sugandi ◽  
Ruminta Ruminta ◽  
Asep Yusuf ◽  
Theresia Romey
Keyword(s):  
Performance Test ◽  
Performance Testing ◽  
Engine Efficiency ◽  
Cylinder Length ◽  
Great Pressure ◽  
Polishing Machine ◽  
And Performance ◽  
Unit Analysis

Hanjeli has a hard rind, so it takes a peeler and polisher to process it. One of the machines used is the Hanjeli Polishing Machine AGR-RM40 in the Faculty of Agriculture, Padjadjaran University. However, this machine has the disadvantage that most of the hanjeli seeds are crushed and are not polished. This is due to the polishing space which is quite narrow so that it puts great pressure on the hanjeli seeds during the polishing. Meanwhile, the existence of not polished hanjeli was caused by friction between the cylinders and hanjeli which is not maximum. Therefore, this machine needs to be modified to improve the results of a better polishing. The method used in this research was engineering with several stages, such as designing a polishing unit, analysis, and performance testing on hanjeli batu and hanjeli pulut. The modification of the Polishing Unit on Hanjeli Polishing Machine (MPBH-0219) has a cylinder length dimension of 167 mm and a diameter of 37.9 mm. Based on the performance test, this machine is good and worth using where actual capacity is obtained 35 kg / hour, 96 % engine efficiency, 58,46 % dumping yield, 0.50 performance, and 1.30 kW actual power requirements. Keywords: Hanjeli Polishing Machine, Modification, Performance Test.

scholarly journals Ag/AgCl Reference Electrode Based on Thin Film of Arabic Gum Membrane

2018 ◽  
Vol 18 (3) ◽  
pp. 479 ◽  
Author(s):  
Sagir Alva ◽  
Aiman Sajidah Binti Abdul Aziz ◽  
Mohd Ismahadi Bin Syono ◽  
Wan Adil Bin Wan Jamil
Keyword(s):  
Performance Test ◽  
Reference Electrode ◽  
Performance Testing ◽  
Optimum Concentration ◽  
Stability Testing ◽  
Arabic Gum ◽  
Linear Distance ◽  
Double Junction ◽  
And Performance ◽  
Hydrogel Films

The Ag/AgCl reference electrode based on the Arabic Gum (AG) hydrogel films was successfully developed. The Arabic Gum concentration used in this study was 10–40% (w/v) with an optimum concentration of 20% (w/v). In this study, reference electrode performance testing is based on DmV response of Cl-ion’s measurements, stability tests and performance testing against ISE sensors such as K+, NH4+, and NO3-. The Ag/AgCl based reference electrode of the Arabic Gum film shows an average DmV of 4.0 ± 0.7 mV when response test is performed against a standard Ag/AgCl double junction electrode in various concentrations of Cl-ion’s. Meanwhile, in stability testing conducted in a 0.01 M KCl solution for 72 h found drift of < 0.6 mV/h. The reference performance test of the Arabic Gum reference electrode with three types of ISE NH4+, K+ and NO3- commercial sensors obtaining a slope closer to the Nernst value is 54.9 ± 0.9, 52.3 ± 0.5 and -53.2 ± 0.2 mV/dec with all having a linear distance of 0.1–10-5 M.

scholarly journals Functional and performance test of modified lug wheel on two wheels tractor with pivot type trailer

2021 ◽  
Vol 922 (1) ◽  
pp. 012016
Author(s):  
M Idkham ◽  
M Dhafir ◽  
Safrizal ◽  
L Putri
Keyword(s):  
Performance Test ◽  
Performance Testing ◽  
Oil Fields ◽  
Functional Testing ◽  
Wheel Slip ◽  
Sloping Land ◽  
Turning Radius ◽  
Fresh Fruit Bunches ◽  
And Performance ◽  
The Stability

Abstract Palm oil fields with slopes require special wheels for transportation for transporting fresh fruit bunches (FFB), the special wheels in question are modified wheels from the existing cage wheel, the modified wheels can adjust the slope conditions on the land with the lug angle adjustment mechanism. The objective of this study was to test the functional and performance of the modified lug wheel as a means of transporting FFB on sloping land using a hand tractor on a pivot type trailer. Functional testing on the modified lug wheel was carried out by observing changes in the angle of the lugs (0, 15, 30, 45)0 by lifting one of the tractor shafts first using a jack, after which the locking pins were released. The angle change rim can be moved clockwise or anticlockwise by hand according to the desired lug angle. Performance testing on the modified lug wheel is carried out by observing and calculating the slip on the wheel. Functional testing on trailer pivots is carried out by observing all components of the towing system when installed and operated, to determine whether the trailer towing system can function properly. Performance testing on the pivot trailer is done by observing and calculating the turning radius when the tractor turns. Performance testing is also carried out by observing the stability of the two-wheel tractor and trailer. The slope of the land and the angle of the lugs greatly affect wheel slip, the higher the slope on a land, the higher the possibility of wheel slippage during operation. The test results show that the use of modified lug wheels shows better performance at 30° lug angle, as seen from the smaller slip value at 30° lug angle.

Development of a Multi-Task Robotic Transplanting Workcell for Greenhouse Seedlings

2018 ◽  
Vol 34 (2) ◽  
pp. 335-342 ◽  
Author(s):  
Luhua Han ◽  
Hanping Mao ◽  
Francis Kumi ◽  
Jianping Hu
Keyword(s):  
Control System ◽  
Performance Test ◽  
Programmable Logic ◽  
Double Row ◽  
Dynamic Accuracy ◽  
Working Space ◽  
Performance Requirements ◽  
Accuracy Test ◽  
Chain Transmission ◽  
And Performance

Abstract.A multi-task robotic transplanting workcell for greenhouse seedlings was developed and evaluated. The workcell mainly consists of a transplanting system, two conveyors, a filling unit, and a control system. The transplanting system having multi-grippers was designed to automatically pick-up and plant whole rows of seedlings. The conveyors were designed with the pallet-type double-row chain transmission system which moves the plug trays and pots to the predefined working space of the multi-grippers. The filling unit was designed for automatically filling the growing pots with soil and dibbling holes prior to planting seedlings. The control system coordinates the functionality of the aforementioned function units for flexible automation using a programmable logic controller (PLC). Consequently, a prototype of the multi-task robotic transplanting workcell was constructed. The system was made to undergo dynamic accuracy test and to evaluate the ability of the multi-grippers to meet its design and performance requirements. The results of the performance test under local seedling production conditions showed that the overall success ratio in transplanting operation was up to 90% at the efficiency of 960 plants/h/gripper. Keywords: Greenhouse, Multi-task, Seedlings, Transplanting.

Maternal effects and selection response with an application to sheep data

1976 ◽  
Vol 22 (3) ◽  
pp. 359-369 ◽  
Author(s):  
J. P. Hanrahan
Keyword(s):  
Maternal Effects ◽  
Performance Test ◽  
Performance Testing ◽  
Selection Response ◽  
Genetic Effects ◽  
Progeny Testing ◽  
Test Selection ◽  
Selection Strategies ◽  
Maternal Performance ◽  
And Performance

SUMMARYThe implications of genetic variation in maternal performance for the relative merits of common selection strategies have been investigated. If the accuracy of progeny testing is computed without taking maternal effects into account, the estimate is biased upward. This bias increases as the correlation between direct and maternal genetic effects decreases from positive to negative values. The relative efficiency of progeny and performance test selection is a function of the heritability of direct and maternal genetic effects and the correlation between them. In terms of genetic gain per unit time, progeny testing is almost always less efficient than performance testing. For sire line improvement progeny testing is relatively more useful but is still likely to be less efficient than performance test selection unless there is a negative correlation between direct and maternal genetic effects or the correlation between purebred and crossbred direct genetic effects is very low or negative.Analysis of body weight at 6 and 14 weeks of age in Galway sheep has shown that maternal genetic effects are an important source of variation in this population.

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