Research on the specific solution of intelligent water conservancy remote monitoring system

　　1、 Overall system structure

　　The intelligent remote monitoring system proposed in this paper mainly collects the field real-time water level and rainfall data in a certain period, and then transmits it to the central control center of the system by the lower computer. Combined with the irrigation data of the irrigation area in recent years, the fuzzy theory method is adopted and the relevant information processing software is used to calculate the most suitable water supply, Then realize the remote control of front irrigation water pump through GPRS, so as to maximize the benefit of farmland irrigation, and then realize the intelligent control of irrigation system. The system remotely controls the water pump and valve by computer, collects the synchronous data of multiple instruments, and then carries out relevant processing. The system adopts a distributed control system composed of sensor, field control module (including digital output control valve and water pump), control host computer and RS-485 fieldbus. RS-485 fieldbus is the link connecting the equipment of intelligent system. Rrs-485 network uses two twisted pairs to receive and send data. The maximum distance of its interface transmission equipment is more than 1mk. Repeaters can be used to extend the transmission distance of the system and expand the system. The framework of intelligent control system in irrigation area is: each sub irrigation area is equipped with corresponding control instruments, which are connected by RS-485 fieldbus, and the data is transmitted to the remote control system through GPRS interface through the Internet. According to the function, the intelligent remote control system can be divided into three subsystems: irrigation area data acquisition, fuzzy theory decision-making and database. The specific modules include eight modules: pump station control, gate control, rainfall acquisition, irrigation area water level acquisition, key equipment detection, communication, query and decision-making. The data acquisition system is in the lower computer of the irrigation area, while the data processing and decision-making subsystem is in the client.

　　2、 Irrigation area data acquisition system

　　The data acquisition system in the irrigation area adopts the configuration software design to control the irrigation site, which includes L6 relay output modules to control a water pump and 50 solenoid valves; Three irrigation area instrument control modules measure and read one rainfall sensor and two water level sensors respectively; There are 7 open channel flow calculators to collect the flow at the corresponding place in the irrigation area. Because the interface communication protocol of the controller software configuration software is different from that of the field instrument control module and the digital quantity module, and the open channel flow meter is self-developed and designed, and a single RS-485 fieldbus should be used. Therefore, the data transmission of the data acquisition subsystem in the irrigation area should be realized by three RS-485 fieldbuses. The control interface uses the form of animation to explain the system process, and users can understand the scope of the control area in real time. If the hardware is damaged or abnormal, an automatic alarm will be generated inside the system.

　　3、 Database system '

　　1. GPRS Remote Transmission

　　1.1 establishing connections

　　In the field control system, GPRS users will automatically log in to the corresponding network of GPRS after authentication, and then use the wireless base station system to connect with the GGSN of the switching center and the Internet. At this time, the field controller can use GRPS to send a connection request to the remote control center. At this time, the remote control center and field control equipment can realize the two-way transmission of data through GPRS.

　　2 server / client mode

　　The system studied in this paper is an intelligent remote control system, so the system model can adopt distributed structure. The server client service mode is a representative asymmetric distribution system. The connection request between the field control device and the server can be realized through this mode. Once the server receives the request from the field control device, it can communicate normally. Generally, the server will start from the sleep state after the client sends the connection request, and handle the request service of the client accordingly. Since the system adopts GPRS for two-way transmission, data flow service should be selected.

　　1.3 data storage and forwarding design

　　The information control and management of remote monitoring center can only be completed correctly with the help of reliable data communication. The system sends a request from the client to the server, and the server then performs the design of relevant data storage and forwarding, that is to say, the client can realize the functions of data monitoring and information management of the remote monitoring center. However, the on-site operation control equipment and the receiving on-site control equipment

　　The information transmitted by the standby equipment can be managed by the client only after being forwarded by the server, that is, the server is the communication link between the client and the field control equipment.

　　1.4 remote control operation

　　The client first sends the on-site control status command with the purpose of query to the server. After receiving it, the server will transfer it to the on-site control equipment, transmit the feedback information of the on-site control equipment to the database, and synchronously transmit the feedback information to the client. Once the client receives the feedback information from the on-site control, it will process the next operation in combination with the water conservancy information of the irrigation area over the years. During the implementation of remote control, the control query instruction sent by the client is sent to the field control equipment through the server, and a receipt command is confirmed to the server after it is processed. At this time, the server transmits the user's operation information and user name to the database for recording. At this time, the client receives the receipt information of successful operation and completes the remote control operation.

　　2. Database processing

　　The system chooses to use SQL Server database and Microsoft ADO database engine. System users can access the database through ADO to query and analyze various water regime information, and can realize the function of automatic production of relevant charts to facilitate printing and output analysis. The specific query functions include: rainfall information query, that is, the rainfall statistics of a day in a year or the average rainfall statistics of a month in a year; For flow information query, enter the corresponding query date or a certain interval in the interface to obtain the flow information of all collection points on this date or time period; Query the historical information of water level, and customize different query intervals according to different needs to obtain the corresponding historical information of water level.

　　4、 Fuzzy control decision system

　　First of all, the rainfall, water consumption and other data information of the irrigation area over the years should be fully analyzed to form an empirical rule base (knowledge base). Considering the convenience of modification and maintenance, the knowledge base and its subordinate function table can be stored in the database. Then the real-time information such as the growth date of crops in the irrigation area, the rainfall in a certain period of the year and the field water level are taken as the input. After obtaining the input variables of the fuzzy controller, the fuzzy reasoning and judgment are made according to the calculation principles of fuzzy theory such as taking the big and taking the small, combined with the built knowledge base.