| Artificial rainfall simulation system is an effective test method for major researches, such as water cycle & related land surface processes, high-efficiency utilization of rainfall, and soil and water conservation, etc. With artificial rainfall simulation system, test conditions could be controlled to simulate various rainfall environments (including different rainfall, intensity, time and space, underlying surface, and slope composition, etc.), to make up results which cannot reached under natural rainfall conditions or further prove research results under natural rainfall conditions. Artificial rainfall simulation could also reduce test cycle, and speed up research progress on water infiltration and soil erosion. The combination of different requirements on rainfall system from relevant tests could not only meet test requirements, but also get preparation for overall system tests. Therefore, the development of artificial rainfall system is with very important significance under current social situation with great advocation on establishing harmonious society and increasing attention on ecological environment protection.Fieldbus is a complete digital communication network with two-way transmission and multiple branching constructions, connecting intelligent field equipment and control room system. It's not only a basic network, but also an open and complete distribution control system, and an integrated technology mainly with contents including intelligent sensing, control, computer and digital communication, etc. Openness, diversity and digital communication are the most distinctive characters of this network. The fieldbus applied in this thesis is controller area network (CAN). With advantages including abound chips, high reliability, low R&D cost, real-time performance and flexibility, it's mainly applicable for small-scale system with relatively high requirement on real-time capability.In accordance with design requirements, the system applies distributed control method for clients and servers. With the application of industrial control computer for clients and modular design for servers, communications between clients and servers are realized with CAN. All parameters in the system and server module control parameters could be set and transmitted with clients. With the application of configuration software in monitoring with clients and the basis of engineering application, picture fabrication, animation linking, real-time database and failure alarm, etc. are realized to meet real-time monitoring requirement on artificial rainfall process and monitor field operating conditions for artificial rainfall vividly.The research content of this thesis is about a monitoring system with the application on artificial rainfall simulation. With the basis on industrial control software and application of current test facilities on artificial rainfall simulation, it combines common test equipment and industrial control software, improves automatic control links, solves the problem of inconvenience on manual adjustment of rainfall intensity by modifying the control system, and realizes both manual control and automatic control on artificial rainfall simulation system for various period, rainfall intensity and distribution. The application of configuration software system could not only reduce labor intensity and improve test efficiency, but also meet demands on artificial rainfall simulation in a better way.The result shows that artificial rainfall simulation system has met the set target:1. The rainfall intensity range is relatively wide as 12～300mm/h; 2. It's with great sensitivity while starting and stopping raining, and sensitive to intensity change. It's less than 10 seconds from starting the valve to stable rainfall, and less than 5 seconds from closing the valve to complete stopping raining.3. Industrial control software on artificial rainfall system. |
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