scholarly journals Formalization of dynamic model of pneumatic drive with variable structure

2018 ◽  
Vol 226 ◽  
pp. 02022
Author(s):  
Elena N. Obukhova ◽  
Vyacheslav I. Grishchenko ◽  
Grigoriy A. Dolgov
Keyword(s):  
Mathematical Model ◽  
High Speed ◽  
Low Cost ◽  
Technical Problem ◽  
Variable Structure ◽  
Pneumatic Cylinder ◽  
Pneumatic Drive ◽  
Environmental Friendliness ◽  
Pneumatic Valves ◽  
Speed And Accuracy

The work is devoted to solving the actual technical problem of increasing the speed and accuracy of pneumatic servo drives. Pneumatic drives have a large number of advantages (high speed of the output link, environmental friendliness, low cost, etc.). But having a high compressibility of compressed air limits the possibility of realizing optimal trajectories of motion of control objects. The complexity in the organization of controlling the follow-up pneumatic drive is also introduced by a mathematical apparatus that takes into account the thermodynamic processes during the filling and emptying of the working cavities of a pneumatic cylinder. In connection with this, the goal of this work was the development of a mathematical model of a servomotor with a variable structure that takes into account the various structures of pneumatic valves with proportional control. The proposed mathematical model will make it possible to use the synergetic approach in controlling the pneumatic drive. This makes it possible to take into account not less important drive parameters such as energy efficiency, etc., with increasing speed and accuracy of the drive.

scholarly journals Application of Gas Foil Bearings in China

2021 ◽  
Vol 11 (13) ◽  
pp. 6210
Author(s):  
Yu Hou ◽  
Qi Zhao ◽  
Yu Guo ◽  
Xionghao Ren ◽  
Tianwei Lai ◽  
...  
Keyword(s):  
High Speed ◽  
Low Cost ◽  
Small Scale ◽  
Environmental Friendliness ◽  
Wear Resistant Coatings ◽  
Foil Bearings ◽  
Foil Bearing ◽  
Turbo Machinery ◽  
Principle Theory ◽  
Rotor Dynamic

Gas foil bearing has been widely used in high-speed turbo machinery due to its oil-free, wide temperature range, low cost, high adaptability, high stability and environmental friendliness. In this paper, state-of-the-art investigations of gas foil bearings are reviewed, mainly on the development of the high-speed turbo machinery in China. After decades of development, progress has been achieved in the field of gas foil bearing in China. Small-scale applications of gas foil bearing have been realized in a variety of high-speed turbo machinery. The prospects and markets of high-speed turbo machinery are very broad. Various high-speed turbomachines with gas foil bearings have been developed. Due to the different application occasions, higher reliability requirements are imposed on the foil bearing technology. Therefore, its design principle, theory, and manufacturing technology should be adaptive to new application occasions before mass production. Thus, there are still a number of inherent challenges that must be addressed, for example, thermal management, rotor-dynamic stability and wear-resistant coatings.

scholarly journals Femtosecond System with Pulse Pumping of Seed Laser and Amplifier by Using a Single Power Unit

2021 ◽  
Vol 12 (1) ◽  
pp. 23-29
Author(s):  
S. A. Tikhomirov
Keyword(s):  
Power Unit ◽  
High Speed ◽  
Low Cost ◽  
Laser System ◽  
Technical Problem ◽  
Ultrashort Pulses ◽  
Pulse Mode ◽  
Practical Implementation ◽  
Laser Head ◽  
Single Power

For several decades development of methods for generating ultrashort pulses has been an  independent urgent scientific and technical problem. There is a constant improvement both in the methods of such pulses receiving and in methods of their use. The aim of this work was to investigate the possibility of realizing the coordinated  operation  of  two  fundamentally  different  types  of  pump  lasers for the femtosecond oscillator and amplifier based on one single-lamp laser head and to create on this basis a compact high-power femtosecond system with pulsed pumping and one power unit.The practical implementation of two types of pulsed lasers (nano- and picosecond ones operating, respectively, in Q-switch and modelock regime) on a single laser head with two active elements and one pump lamp is carried out. The required synchronization in time the pump pulse femtosecond amplifier formation and quasi-stationary region of generated pulses in the output radiation of a femtosecond Ti:sapphire is obtained.On this basis a compact, pulse pumped monoblock laser system has been developed that can generate femtosecond pulses with a duration of 50–150 fs with an energy up to 1 mJ and a high enough pulse repetition rate (up to 1 kHz which is determined by the type of laser head and pump unit used). In the developed laser system a compact scheme of a stretcher-compressor with a single common diffraction grating is used.Laser systems of this type characterized by a relatively low cost due to the use of a single power supply unit for simultaneous pumping  of  the  amplifier  and  oscillator,  as  well  as  lower  requirements for the quality of optical elements and usage conditions due to the pulse mode of operation, are quite practical and  can  be  used  both  in  scientific research  in  the  field  of  ultra-high-speed kinetic spectroscopy and nonlinear optics, as well as in numerous technical applications, particular in the precision processing of materials, as optical  simulators  of  the  action  of  heavy  charged  particles  in  testing the radiation resistance of integrated circuits and electronic modules.

Hybrid Fuzzy Logic Algorithm for Position Control of Pneumatic Actuator With 3/2-Way Solenoid Valves

1996 ◽  
Vol 210 (2) ◽  
pp. 167-176 ◽  
Author(s):  
H Wang ◽  
J P T Mo ◽  
N Chen
Keyword(s):  
Fuzzy Logic ◽  
High Speed ◽  
Pulse Width Modulation ◽  
Position Control ◽  
Small Deviation ◽  
Low Cost ◽  
Pneumatic Cylinder ◽  
Control Element ◽  
Fuzzy Logic Algorithm ◽  
Accuracy And Repeatability

Pneumatic positioning devices are inexpensive and also have the advantages of high speed and cleanliness. However, due to the non-linearity of the working medium, pneumatic actuators are not commonly used in industry for programmable positioning applications. Recent researches in this area are mainly concentrated on using expensive servo valves as the control element. However, the systems generally have the problems of instability and load sensitivity. In this paper, a pneumatic cylinder is controlled by a series of low-cost two-state solenoid valves. The components in the system are taken from commercial stock items that do not have the tight tolerance demanded by traditional control methodologies. The inaccuracies of the components are compensated by a hybrid fuzzy logic algorithm which incorporates additional fuzzy pulse width modulation and small deviation control logics to achieve high accuracy and repeatability at all stroke positions.

Development and production experience of the multilayer curtain-coated linerboard of Ji’an PM No. 3,

TAPPI Journal ◽  
2014 ◽  
Vol 13 (2) ◽  
pp. 17-25
Author(s):  
JUNMING SHU ◽  
ARTHAS YANG ◽  
PEKKA SALMINEN ◽  
HENRI VAITTINEN
Keyword(s):  
Titanium Dioxide ◽  
High Speed ◽  
Food Packaging ◽  
Production Efficiency ◽  
Positive Impact ◽  
Low Cost ◽  
Board Structure ◽  
Flexographic Printing ◽  
Curtain Coating ◽  
Coating Formulations

The Ji’an PM No. 3 is the first linerboard machine in China to use multilayer curtain coating technology. Since successful startup at the end of 2011, further development has been carried out to optimize running conditions, coating formulations, and the base paper to provide a product with satisfactory quality and lower cost to manufacture. The key challenges include designing the base board structure for the desired mechanical strength, designing the surface properties for subsequent coating operations, optimizing the high-speed running of the curtain coater to enhance production efficiency, minimizing the amount of titanium dioxide in the coating color, and balancing the coated board properties to make them suitable for both offset and flexographic printing. The pilot and mill scale results show that curtain coating has a major positive impact on brightness, while smoothness is improved mainly by the blade coating and calendering conditions. Optimization of base board properties and the blade + curtain + blade concept has resulted in the successful use of 100% recycled fiber to produce base board. The optical, mechanical, and printability properties of the final coated board meet market requirements for both offset and flexographic printing. Machine runnability is excellent at the current speed of 1000 m/min, and titanium dioxide has been eliminated in the coating formulations without affecting the coating coverage. A significant improvement in the total cost of coated white liner production has been achieved, compared to the conventional concept of using virgin fiber in the top ply. Future development will focus on combining low cost with further quality improvements to make linerboard suitable for a wider range of end-use applications, including frozen-food packaging and folding boxboard.

Low-Cost High-Speed Techniques for Real-Time Simulation of Power Electronic Systems

2007 ◽  
Author(s):  
R. E. Crosbie ◽  
J. J. Zenor ◽  
R. Bednar ◽  
D. Word ◽  
N. G. Hingorani
Keyword(s):  
Real Time ◽  
High Speed ◽  
Low Cost ◽  
Electronic Systems ◽  
Power Electronic ◽  
Real Time Simulation ◽  
Time Simulation

scholarly journals A review of biomass materials for advanced lithium–sulfur batteries

2019 ◽  
Vol 10 (32) ◽  
pp. 7484-7495 ◽  
Author(s):  
Huadong Yuan ◽  
Tiefeng Liu ◽  
Yujing Liu ◽  
Jianwei Nai ◽  
Yao Wang ◽  
...  
Keyword(s):  
Recent Progress ◽  
Low Cost ◽  
High Abundance ◽  
Chemical Adsorption ◽  
Environmental Friendliness ◽  
Lithium Sulfur Batteries ◽  
Biomass Materials ◽  
Physical And Chemical ◽  
Lithium Sulfur

This review summarizes recent progress of biomass-derived materials in Li–S batteries. These materials are promising due to their advantages including strong physical and chemical adsorption, high abundance, low cost, and environmental friendliness.

High-speed electro-optic switch using buried electrode structure in polymer Mach–Zehnder waveguide

2016 ◽  
Vol 30 (06) ◽  
pp. 1650063 ◽  
Author(s):  
Jingwen Sun ◽  
Jian Sun ◽  
Yunji Yi ◽  
Lucheng Qv ◽  
Shiqi Sun ◽  
...  
Keyword(s):  
Insertion Loss ◽  
Rise Time ◽  
High Speed ◽  
Low Cost ◽  
Characteristic Parameters ◽  
Electrode Structure ◽  
Processing Cost ◽  
Electro Optic ◽  
Disperse Red 1 ◽  
Excellent Photostability

A low-cost and high-speed electro-optic (EO) switch using the guest–host EO material Disperse Red 1/Polymethyl Methacrylate (DR1/PMMA) was designed and fabricated. The DR1/PMMA material presented a low processing cost, an excellent photostability and a large EO coefficient of 13.1 pm/V. To improve the performance of the switch, the in-plane buried electrode structure was introduced in the polymer Mach–Zehnder waveguide to improve the poling and modulating efficiency. The characteristic parameters of the waveguide and the electrodes were carefully designed and the fabrication process was strictly controlled. Under 1550 nm, the insertion loss of the device was 12.7 dB. The measured switching rise time and fall time of the switch were 50.00 ns and 54.29 ns, respectively.

Green water-based binders for LiFePO4/C cathode in Li-ion batteries: a comparative study

2021 ◽  
Author(s):  
Xiaojing Zhang ◽  
xinyi Ge ◽  
Zhigang Shen ◽  
Han Ma ◽  
Jingshi Wang ◽  
...  
Keyword(s):  
Comparative Study ◽  
Polyvinylidene Fluoride ◽  
Low Cost ◽  
Green Water ◽  
Li Ion Batteries ◽  
Environmental Friendliness ◽  
Water Based ◽  
Li Ion

Compared with environmentally harmful binder polyvinylidene fluoride (PVDF) in Li-ion batteries (LIBs), water-based binders have many advantages, such as low cost, rich sources and environmental friendliness. In this study, various...

scholarly journals A New Method to Verify the Measurement Speed and Accuracy of Frequency Modulated Interferometers

2021 ◽  
Vol 11 (13) ◽  
pp. 5787
Author(s):  
Toan-Thang Vu ◽  
Thanh-Tung Vu ◽  
Van-Doanh Tran ◽  
Thanh-Dong Nguyen ◽  
Ngoc-Tam Bui
Keyword(s):  
Phase Change ◽  
High Speed ◽  
Measurement Accuracy ◽  
Slow Motion ◽  
New Method ◽  
Virtual Displacement ◽  
Electro Optic ◽  
Lock In ◽  
Speed And Accuracy ◽  
Electro Optic Modulator

The measurement speed and measurement accuracy of a displacement measuring interferometer are key parameters. To verify these parameters, a fast and high-accuracy motion is required. However, the displacement induced by a mechanical actuator generates disadvantageous features, such as slow motion, hysteresis, distortion, and vibration. This paper proposes a new method for a nonmechanical high-speed motion using an electro-optic modulator (EOM). The method is based on the principle that all displacement measuring interferometers measure the phase change to calculate the displacement. This means that the EOM can be used to accurately generate phase change rather than a mechanical actuator. The proposed method is then validated by placing the EOM into an arm of a frequency modulation interferometer. By using two lock-in amplifiers, the phase change in an EOM and, hence, the corresponding virtual displacement could be measured by the interferometer. The measurement showed that the system could achieve a displacement at 20 kHz, a speed of 6.08 mm/s, and a displacement noise level < 100 pm//√Hz above 2 kHz. The proposed virtual displacement can be applied to determine both the measurement speed and accuracy of displacement measuring interferometers, such as homodyne interferometers, heterodyne interferometers, and frequency modulated interferometers.

scholarly journals Reinforcement of Recycled Aggregate by Microbial-Induced Mineralization and Deposition of Calcium Carbonate—Influencing Factors, Mechanism and Effect of Reinforcement

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 887
Author(s):  
Chunhua Feng ◽  
Buwen Cui ◽  
Haidong Ge ◽  
Yihong Huang ◽  
Wenyan Zhang ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Global Economy ◽  
Low Cost ◽  
High Water ◽  
Strengthening Mechanism ◽  
Recycled Aggregate ◽  
Strengthening Effect ◽  
Calcium Carbonate Precipitation ◽  
Environmental Friendliness ◽  
Advantages And Disadvantages

Recycled aggregate is aggregate prepared from construction waste. With the development of a global economy and people’s attention to sustainable development, recycled aggregate has shown advantages in replacing natural aggregate in the production of concrete due to its environmental friendliness, low energy consumption, and low cost. Recycled aggregate exhibits high water absorption and a multi-interface transition zone, which limits its application scope. Researchers have used various methods to improve the properties of recycled aggregate, such as microbially induced calcium carbonate precipitation (MICP) technology. In this paper, the results of recent studies on the reinforcement of recycled aggregate by MICP technology are synthesized, and the factors affecting the strengthening effect of recycled aggregate are reviewed. Moreover, the strengthening mechanism, advantages and disadvantages of MICP technology are summarized. After the modified treatment, the aggregate performance is significantly improved. Regardless of whether the aggregate was used in mortar or concrete, the mechanical properties of the specimens were clearly improved. However, there are some issues regarding the application of MICP technology, such as the use of an expensive culture medium, a long modification cycle, and untargeted mineralization deposition. These difficulties need to be overcome in the future for the industrialization of regenerated aggregate materials via MICP technology.

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