PI Control of Proportional Valve-Cylinder Water Hydraulic System

2014 ◽  
Vol 548-549 ◽  
pp. 977-984
Author(s):  
Xin Ba ◽  
Xiao Hui Luo ◽  
Xu Feng Zhao ◽  
Yu Quan Zhu

Water hydraulic components have been developed rapidly in recent years. However many problems such as low lubricity and leakage limited the performance of them, especially water proportional valves. A proportional valve- hydraulic cylinder system with tap water as working medium is chosen as object to investigate the performance of water hydraulic system. With regarding to the weaknesses of the selected 4/3 proportional valve including lag, dead zone and nonlinearity, an integral separation PI arithmetic based close-loop controller is developed. Experiments results verified the electro-hydraulic proportional system of fast response speed and high accuracy.

2011 ◽  
Vol 201-203 ◽  
pp. 2206-2211
Author(s):  
Yan Min Li ◽  
Zhi Hua Liu ◽  
Dong Wang ◽  
Yong Zhang

The paper discusses the performance of a hydraulic system controlling the shifting action of a construction vehicle transmission. Based on the principle of the hydraulic system of the transmission, a simulation model of the hydraulic system is established using AMEsim software. The simulation results indicate that the double-step hydraulic cylinder structure has an advantage of a fast, smooth and reliable shifting. The shifting connecting and separating overlap time of two clutches can be controlled precisely by an electronic joystick. The fast response speed can be ensured because using screw-in cartridge valves acting as the directional valves. Some techniques of improving the shifting quality are obtained. There is a great reference for the construction vehicles’ transmission in the future.


2013 ◽  
Vol 2013.19 (0) ◽  
pp. 497-498
Author(s):  
Toshiki HATAYAMA ◽  
Sho AKAZAWA ◽  
Kenji SUZUKI ◽  
Yohichi NAKAO

2000 ◽  
Vol 41 (12) ◽  
pp. 215-222 ◽  
Author(s):  
S. M. Soini ◽  
K. T. Koskinen ◽  
M. Vilenius ◽  
J. A. Puhakka

Water hydraulics uses tap water or demineralised water as a pressure medium and has fewer environmental impacts than oil-using hydraulics. The applicability is restricted by the microbial quality of the medium. The objectives of this study were to determine whether microbes grow in the pressure medium of a water hydraulic system, biofilm is formed on the surfaces and to describe the diversity of bacteria that survive and grow in water hydraulic systems. A pilot-scale water hydraulic system was used in the experiments. The viable counts in the pressure medium increased in three days from 102 to 3 ×104 cfu/ml followed by a gradual decrease towards the steady-state concentration of 6× 1034 cfu/ml. The total cell numbers decreased from 3×105 to 2 ×104 cells/ml during the three weeks of operation indicating attachment onto the system surfaces as biofilms. The biofilm cell densities on collector slide surfaces varied between 7 ×103 and 1.2 ×104 cells/cm2 after 21 days of operation. The phosphatase activity in the pressure medium was in conformity with the numbers of viable bacteria. The enzymatic activities (α- and β- glucosidase, phosphatase, aminopeptidase) varied between 0.4 and 300 nmol/lh. The diversity of bacteria growing in the system was wide and differed from that of tap water.


Author(s):  
Liu Yinshui ◽  
Yang Yousheng ◽  
Li Zhuangyun

In water-hydraulic power systems cavitation is more likely to happen than in oil-hydraulic power systems because of the high vaporous pressure of water. A multi-stage throttle, which consists of two or more orifices in a throttle, is an effective way to avoid or reduce cavitation damage. In this research, the cavitation characteristics of two-stage throttles are analysed theoretically and compared with a single-stage. Then, experiments are conducted to investigate the flow and cavitation characteristics of multi-stage throttles including two kinds of two-stage throttles and one of a three-stage kind. All the experiments are carried out under the two cases with and without backpressure, respectively. The working medium is tap water. Experimental results show that the shape of the multi-stage throttle and operating conditions have remarkable effects on the flow and cavitation characteristics.


2021 ◽  
Vol 67 (5) ◽  
pp. 223-234
Author(s):  
Mingxing Han ◽  
Yinshui Liu ◽  
Yitao Liao ◽  
Shucai Wang

As the key control component of the water hydraulic systems, the water hydraulic proportional valve has a significant influence on the control performance of the systems. Due to the poor viscosity and lubricity of water, the valve spool resistance is large and non-linear. In this study, a novel fast-response water hydraulic proportional valve is presented. The actuator of the valve adopts a voice coil motor (VCM), which has the advantages of fast response, high control precision and small volume. In order to realize the fast control of the valve, a lever amplifier is designed to obtain enough actuation force. A detailed and precise non-linear mathematical model of the valve considering both the valve’s structural parameters and VCM electromagnetic characteristics is developed. A comprehensive performance simulation analysis has been carried out, mainly divided into an electromagnetic simulation, an analysis of the characteristics of the lever magnifier, and a dynamic performance simulation of the valve. The simulation results show that the adjusting time is about 28ms, and the maximum overshoot is about 5 %. The step response rise time is about 15 ms. The test rig of the valve and VCM have been built. The test results of the prototype show that the optimal stroke range of VCM is 4 mm to 15 mm. The maximum overshoot of the valve is around 10 %; the adjusting time is about 30 ms in the opening process and 35 ms in the closing process. The test results prove that the valve has good static and dynamic control performance.


2012 ◽  
Vol 2012 (0) ◽  
pp. _J113026-1-_J113026-3
Author(s):  
Toshiki HATAYAMA ◽  
Sho AKAZAWA ◽  
Kenji SUZUKI ◽  
Yohichi NAKAO

2013 ◽  
Vol 668 ◽  
pp. 420-425 ◽  
Author(s):  
Ning Xie ◽  
Xi Chen ◽  
Jin Jin Guo

Focusing on the performance of proportional valve controlled cylinder, by using AMESim simulation software, dynamic performance of the system has been simulated. Starting by the control strategy, using Genetic Algorithm,the PID parameters which can affect the hydraulic cylinder position accuracy will be optimized. The simulation results show that the optimized parameters can improve system performance, and achieved excellent results.


Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 648
Author(s):  
Aijie Liang ◽  
Jingyuan Ming ◽  
Wenguo Zhu ◽  
Heyuan Guan ◽  
Xinyang Han ◽  
...  

Breath monitoring is significant in assessing human body conditions, such as cardiac and pulmonary symptoms. Optical fiber-based sensors have attracted much attention since they are immune to electromagnetic radiation, thus are safe for patients. Here, a microfiber (MF) humidity sensor is fabricated by coating tin disulfide (SnS2) nanosheets onto the surface of MF. The small diameter (~8 μm) and the long length (~5 mm) of the MF promise strong interaction between guiding light and SnS2. Thus, a small variation in the relative humidity (RH) will lead to a large change in optical transmitted power. A high RH sensitivity of 0.57 dB/%RH is therefore achieved. The response and recovery times are estimated to be 0.08 and 0.28 s, respectively. The high sensitivity and fast response speed enable our SnS2-MF sensor to monitor human breath in real time.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Ting Zhang ◽  
Shibin Li

AbstractIn this manuscript, the inorganic perovskite CsPbI2Br and CsPbIBr2 are investigated as photoactive materials that offer higher stability than the organometal trihalide perovskite materials. The fabrication methods allow anti-solvent processing the CsPbIxBr3−x films, overcoming the poor film quality that always occur in a single-step solution process. The introduced diethyl ether in spin-coating process is demonstrated to be successful, and the effects of the anti-solvent on film quality are studied. The devices fabricated using the methods achieve high-performance, self-powered and the stabilized photodetectors show fast response speed. The results illustrate a great potential of all-inorganic CsPbIxBr3−x perovskites in visible photodetection and provide an effective way to achieve high performance devices with self-powered capability.


2021 ◽  
Vol 9 (14) ◽  
pp. 4799-4807
Author(s):  
Yong Zhang ◽  
Weidong Song

P-CuZnS/n-GaN UV photodetector is prepared by a simple chemical bath deposition, showing excellent self-powered properties, including ultrahigh on/off ratio (3 × 108), fast response speed (0.14/40 ms) and large detectivity of 3 × 1013 Jones.


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