scholarly journals Study on the Structure and Performance of an Antagonistic Pneumatic Bidirectional Rotary Joint

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Hongbo Liu ◽  
Guodong Sun ◽  
Dexu Geng ◽  
Junye Li

An antagonistic pneumatic bidirectional rotary flexible joint was developed to improve both safety and environmental adaptability of service robots and associated human interactions. The joint comprises two semicircular rotary actuators with positive and negative symmetrical distributions and a pneumatic brake. As such, it achieves forward and reverse rotations, and its damping and braking are adjustable in real time, enabling it to maintain its position. According to the force/torque balance at the free end of the rotary actuator, the rotation angle static model was established. The relationship between the actuator rotation angle, driving torque, impedance torque, and air pressure was obtained experimentally. The brake airbag was manufactured using additive manufacturing and silicone gel casting technologies. The mathematical model of the braking torque was established next, and the model was verified through experiments. Furthermore, an experimental system was constructed to carry out the air pressure-angle, air pressure-torque, and speed response experiments without the load on the joint. The results have shown that the joint can achieve any position within ± 68.5° when the driving air pressure varies from 0 to 0.30 MPa; the time required to reach the maximum angle was 0.85 s. The joint has shown good adjustable damping characteristics. Lastly, the braking torque reached 4.21 Nm at 0.32 MPa, effectively maintaining the position.

2016 ◽  
Vol 10 (1) ◽  
pp. 70-77
Author(s):  
Jantri Sirait ◽  
Sulharman Sulharman

Has done design tool is a tool of refined coconut oil coconut grater, squeezer coconut milk and coconut oil heating, with the aim to streamline the time of making coconut oil and coconut oil increase production capacity. The research method consists of several stages, among others; image creation tool, procurement of materials research, cutting the material - the material framework of tools and performance test tools. The parameters observed during the performance test tools is time grated coconut, coconut milk bleeder capacity, the capacity of the boiler and the heating time of coconut oil. The design tool consists of three parts, namely a tool shaved coconut, coconut milk wringer and coconut milk heating devices. Materials used for the framework of such tools include iron UNP 6 meters long, 7.5 cm wide, 4 mm thick, while the motor uses an electric motor 0.25 HP 1430 rpm and to dampen the rotation electric motor rotation used gearbox with a ratio of round 1 : 60. the results of the design ie the time required for coconut menyerut average of 297 seconds, coconut milk wringer capacity of 5 kg of processes and using gauze pads to filter coconut pulp, as well as the heating process takes ± 2 hours with a capacity of 80 kg , The benefits of coconut oil refined tools are stripping time or split brief coconut average - average 7 seconds and coconut shell can be used as craft materials, processes extortion coconut milk quickly so the production capacity increased and the stirring process coconut oil mechanically.ABSTRAKTelah dilakukan rancang bangun alat olahan minyak kelapa yaitu alat pemarut kelapa, pemeras santan kelapa dan pemanas minyak kelapa, dengan tujuan untuk mengefisiensikan waktu pembuatan minyak kelapa serta meningkatkan kapasitas produksi minyak kelapa. Metode penelitian terdiri dari beberapa tahapan antara lain; pembuatan gambar alat, pengadaan bahan-bahan penelitian, pemotongan bahan - bahan rangka alat dan uji unjuk kerja alat. Parameter yang diamati pada saat uji unjuk kerja alat adalah waktu parut kelapa, kapasitas pemeras santan kelapa, kapasitas tungku pemanas serta waktu pemanasan minyak kelapa. Rancangan alat terdiri dari tiga bagian yaitu alat penyerut kelapa, alat pemeras santan kelapa dan alat pemanas santan kelapa. Bahan yang dipergunakan untuk rangka alat tersebut  yaitu besi UNP panjang 6 meter, lebar 7,5 cm, tebal 4 mm, sedangkan untuk motor penggerak menggunakan motor listrik 0,25 HP 1430 rpm dan untuk meredam putaran putaran motor listrik dipergunakan gearbox  dengan perbandingan putaran 1 : 60. Hasil dari rancangan tersebut yaitu waktu yang dibutuhkan untuk menyerut kelapa rata-rata 297 detik, kapasitas alat pemeras santan kelapa 5 kg sekali proses dan menggunakan kain kassa untuk menyaring ampas kelapa, serta Proses pemanasan membutuhkan waktu ± 2 jam dengan kapasitas 80 kg. Adapun keunggulan alat olahan minyak kelapa ini adalah waktu pengupasan atau belah kelapa singkat rata – rata 7 detik dan tempurung kelapa dapat digunakan sebagai bahan kerajinan, proses pemerasan santan kelapa cepat sehingga kapasitas produksi meningkat dan proses pengadukan minyak kelapa secara mekanis. Kata kunci : penyerut, pemeras, pemanas,minyak kelapa,olahan minyak kelapa.


Author(s):  
A I Ryazanov

This paper describes the aerohydrodvnamics of processes in chambers of Gorlov's hydro-pneumatic power system. The mathematical model is developed to determine the main parameters of the processes: water and air velocities, air pressure in the chamber, the periods of time required to fill and empty the chambers and the output of energy during the cycle. The results obtained are in agreement with experimental data and model tests.


2019 ◽  
Vol 47 (3) ◽  
pp. 19-26 ◽  
Author(s):  
Elizabeth E. Richard ◽  
Jeffrey R. Davis ◽  
Jin H. Paik ◽  
Karim R. Lakhani

Purpose This paper presents NASA’s experience using a Center of Excellence (CoE) to scale and sustain an open innovation program as an effective problem-solving tool and includes strategic management recommendations for other organizations based on lessons learned. Design/methodology/approach This paper defines four phases of implementing an open innovation program: Learn, Pilot, Scale and Sustain. It provides guidance on the time required for each phase and recommendations for how to utilize a CoE to succeed. Recommendations are based upon the experience of NASA’s Human Health and Performance Directorate, and experience at the Laboratory for Innovation Science at Harvard running hundreds of challenges with research and development organizations. Findings Lessons learned include the importance of grounding innovation initiatives in the business strategy, assessing the portfolio of work to select problems most amenable to solving via crowdsourcing methodology, framing problems that external parties can solve, thinking strategically about early wins, selecting the right platforms, developing criteria for evaluation, and advancing a culture of innovation. Establishing a CoE provides an effective infrastructure to address both technical and cultural issues. Originality/value The NASA experience spanned more than seven years from initial learnings about open innovation concepts to the successful scaling and sustaining of an open innovation program; this paper provides recommendations on how to decrease this timeline to three years.


1978 ◽  
Vol 18 (91) ◽  
pp. 287 ◽  
Author(s):  
MV Carter ◽  
LF Mullett

The paper describes the development of a prototype applicator for delivery of protective mixtures, in aerosol form, to the wounded sapwood surfaces exposed during pruning. The equipment has three components : a 2 litre day-service tank, a light weight belt-mounted piston pump, and a modification of a standard pneumatic-powered pruning handgun. Laboratory tests of the applicator have proved its ability to deliver, repeatedly, a uniform dose of aerosol containing sufficient particulate chemical and/or biological matter to protect apricot sapwood from invasion by Eutypa armeniacae. Field tests of the equipment in two orchards demonstrated that from 90-100 per cent of wounds can be treated for the addition of less than 20 per cent to the time required to prune a tree. Over a period of three weeks' use no mechanical defects developed. Estimated volume of protective fluid required per day, treating up to 90 per cent of wounds, is less than two litres.


2005 ◽  
Author(s):  
Hans True ◽  
Mark Hoffmann ◽  
Per-Anders Jo¨nsson

In the paper we present the three most common European standard freight wagon suspensions. It is characteristic for the European suspensions that they are all primary suspensions without a bolster. The design and the function of their single elements are described. New results on the nature of dry friction and its influence on the damping characteristics are presented. Finally a few theoretical investigations of the dynamics of European freight wagons are surveyed with emphasis on the calculations of the critical speed. The results are compared with corresponding results for American wagons.


Author(s):  
MATTHIAS BOOK ◽  
VOLKER GRUHN ◽  
MALTE HÜLDER ◽  
ANDRÉ KÖHLER ◽  
ANDREAS KRIEGEL

When considering the addition of a mobile presentation channel to an existing web-based application, a key question that has to be answered even before development begins is how the mobile channel's characteristics will impact the user experience and the cost of using the application. If either of these factors is outside acceptable limits, economical considerations may forbid adding the channels, even if it would be feasible from a purely technical perspective. Both of these factors depend considerably on two metrics: The time required to transmit data over the mobile network, and the volume transmitted. The PETTICOAT method presented in this paper uses the dialog flow model and web server log files of an existing application to identify typical interaction sequences and to compile volume statistics, which are then run through a tool that simulates the volume and time that would be incurred by executing the interaction sequences on a mobile channel. From the simulated volume and time data, we can then calculate the cost of accessing the application on a mobile channel, and derive suitable approaches for optimizing cost and response times.


1937 ◽  
Vol 51 (2) ◽  
pp. 75-83 ◽  
Author(s):  
R. G. Herb ◽  
D. B. Parkinson ◽  
D. W. Kerst

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Wai-Yoong Ng ◽  
Chin-Pin Yeo

Clot activator serum tubes have significantly improved turnaround times for result reporting compared to plain tubes. With increasing workload and service performance expectations confronting clinical laboratories with high-volume testing and with particular emphasis on critical analytes, attention has focussed on preanalytical variables that can be improved. We carried out a field study on the test performance of BD vacutainer rapid serum tubes (RSTs) compared to current institutional issued BD vacutainer serum separator tubes (SSTs) in its test result comparability, clotting time, and stability on serum storage. Data from the study population (n=160) of patients attending outpatient clinics and healthy subjects showed that results for renal, liver, lipids, cardiac, thyroid, and prostate biochemical markers were comparable between RSTs and SSTs. Clotting times of the RSTs were verified to be quick with a median time of 2.05 min. Analyte stability on serum storage at 4°C showed no statistically significant deterioration except for bicarbonate, electrolytes, and albumin over a period of 4 days. In conclusion, RSTs offered savings in the time required for the clotting process of serum specimens. This should translate to further trimming of the whole process from blood collection to result reporting without too much sacrifice on test accuracy and performance compared to the current widely used SSTs in most clinical laboratories.


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