An automatic control device for negative pressure irrigation for continuous low-rate water supply at constant soil wetting

Author(s):  
Kechun Wang ◽  
Haiyu Wang ◽  
Junzeng Xu ◽  
Qi Wei ◽  
Zhe Gu ◽  
...  
Author(s):  
Zhiyong Li ◽  
Sibin Zhang ◽  
Wei Liu ◽  
Yuqing Zhao ◽  
Jianling Gao

2016 ◽  
Vol 2016 (2) ◽  
pp. 167-174
Author(s):  
Михаил Рытов ◽  
Mikhail Rytov ◽  
Сергей Шпичак ◽  
Sergey Shpichak

The problems of access control to information and technological resources of automatic control systems for water supply companies are considered. The formalized model of the process of reliable access to information and technological resources is shown. The model takes into account the existence of a multitude of communication channels and a possibility of the organization of the operative cross access. A method to ensure a reliable access to information and technical resources of automatic control systems by water supply companies on the basis of the access policy combination, a scheme of deposit and a preliminary distribution of access authenticators. As a base example there was adopted Blom’s scheme. The method allows ensuring an operative cross access in case of emergency. To ensure an operative access in the method mentioned there was used a scheme of a complete division of a secret in the combination with authenticator evolution. As a basic example the evolution of authenticators based on Lamport’s protocol is considered.


2013 ◽  
Vol 316-317 ◽  
pp. 719-722
Author(s):  
Huan Huan Wang ◽  
Shu Ming Liu ◽  
Fan Lin Meng ◽  
Lu Bai

High level water tank is a commonly used facility to satisfy water demand for people living in high building, which is also the so-called secondary water supply system (SWSS) in China. Due to lack of maintenance, water quality problem has been frequently reported in the SWSS. In the last few decades, anti-negative pressure facility (ANPF) has emerged as a revolutionary approach for solving the pollution in the SWSS. ANPF makes good use of the municipal pipeline pressure, which is the improvement of traditional water supply. However, most of recent research activities mainly focus on the influence of part of water distribution system (WDS). In this paper, the software of EPANET has been applied in the SWSS calculation and simulation. Besides that, the SWSS with ANPF simulation method is proposed to evaluate the effect of other all nodes pressure in the WDS using hydraulic model. As the cases study, the paper analyzed two WDSs with ANPF. After simulation of the SWSS, the result of WDS, which is smaller, indicates that 6 out of the 9 nodes are affected with ANPF and that of WDS, which is larger, demonstrates that 37 out of the 41 nodes are affected and the affected nodes are focused on the confluent of pipes, especially around the ANPF.


2014 ◽  
Vol 701-702 ◽  
pp. 774-779
Author(s):  
Ze Ding Wei ◽  
Ru Tao Han ◽  
Yong Hui Jia

Opening the almond currently rely on the manual to complete and is unable to meet the requirements of mass production. For the design of almonds opening machine of automatic control device, we determine the morphological changes, vibration characteristics, extrusion force changes and other parameters of the almond of opening moments, so as to provide calculation basis for choosing suitable step motor and determining parameters of circuit’s electrical components. Electromagnetic buzzer as a vibration sensor to detect the vibration signal, the photoelectric sensor to detect the almond’s position signal, the proximity switch sensor to detect the working position and amplified signals to process circuits, under the control of MCU, the step motor driving a load let the almond opening process achieve the automatic.


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