棉田滴灌自动控制系统设计

发布时间：2018-01-06 02:14

本文关键词：棉田滴灌自动控制系统设计　出处：《石河子大学》2017年硕士论文　论文类型：学位论文

【摘要】：自动化的节水灌溉系统是现代农业生产的代表性技术,通过智能控制,满足植物在不同生长环境和时期的水肥需求,在节约水资源,减少环境污染的同时,降低劳动力投入,提高农业生产效益,促进农业生产的可持续发展。本研究针对新疆棉花生长的不同时期对需水量和水肥施放量的需求展开研究,考虑棉田滴灌模式,进行了控制系统的整体方案设计,完成了以8051F410芯片为核心控制器,基于ZigBee无线通讯,土壤水分、管道流量等参数在线检测的自动化节水灌溉模糊控制系统设计,该系统可将灌溉作业的相关信息传输给上位机及云端数据库进行存储和查询,以便使用者能够依据灌区作业情况及时调整模糊控制参数设置,提高系统对棉田复杂环境的适应性,节约水资源。论文主要研究内容如下:(1)完成了系统的总体方案设计确定了以PC机为上位机监控平台,单片机为下位机控制器芯片的总体框架,上位机监控平台主要实现人机交互,包括控制指令发送和数据查询与存储;下位机主要实现信息采集、发送,控制决策生成和指令执行;节点之间基于ZigBee通信。(2)完成了水分及水肥耦合二维模糊逻辑控制器设计和仿真选择棉花生长的关键阶段蕾期为主要研究阶段,以棉株生长的0.5米土层水分控制在60-70%为目标,设计了以土壤水分偏差E和土壤水分偏差变化率?E系统的为输入变量,灌水时间T为输出变量的二维模糊逻辑控制器;考虑水肥耦合作用,相仿地设计了水肥耦合二维模糊逻辑控制器,进行模糊控制器的设计;考虑棉花种苗至出苗期、苗期、开花结铃期等和生长阶段对水肥的需求不同,在上位机设计了水肥控制参数的上下限设置模块。基于Matlab生成了模糊控制查询表,通过Simulink模块进行了模糊控制仿真,结果表明,系统经过20s的震荡逐渐趋于稳定,该条件下灌水时间需150min。(3)完成了上位机和下位机设计与实现进行了上位机硬件配置,利用Java Web技术完成上位机和云端MySQL数据库的设计,上位机软件功能模块包括:显示与查询、本地和云端数据库、参数设置、控制接口。进行了下位机硬件和软件设计,硬件系统核心板选用8051F410单片机,完成模糊控制决策,各阀控节点实时采集土壤水分、管道流量及电磁阀启闭状态等数据,通过ZigBee实现主控与节点及节点之间的通信,控制电磁阀动作,实现滴灌自动控制;最后,完成了控制器程序代码的编写和元器件的选型及电路设计。开发了基于模糊逻辑的智能灌溉控制系统。(4)完成了系统安装调试,进行了传感器的测试和控制系统的田间试验。水分传感器测试值与标准检测仪测试值的最带偏差为0.5%,平均偏差为0.27%,表明传感器选型正确,控制系统能够依据土壤水分需求适时启闭灌溉电磁阀,稳定可靠运行。
[Abstract]:Automatic water-saving irrigation system is the representative technology of modern agricultural production. Through intelligent control, it can meet the water and fertilizer demand of plants in different growing environments and periods, while saving water resources and reducing environmental pollution. Reduce labor input, improve the efficiency of agricultural production, promote the sustainable development of agricultural production. Considering the drip irrigation mode in cotton field, the overall scheme of the control system is designed. The 8051F410 chip is used as the core controller, based on ZigBee wireless communication, soil moisture. The fuzzy control system for automatic water-saving irrigation is designed, which can transmit the relevant information of irrigation operation to the host computer and cloud database for storage and query. In order to improve the adaptability of the system to the complex environment of cotton field, the users can adjust the fuzzy control parameters in time according to the operation situation of irrigation area. The main research contents of this paper are as follows: 1) the overall scheme design of the system is completed. The overall frame of the system is established with PC as the monitoring platform and MCU as the lower computer controller chip. The host computer monitoring platform mainly realizes man-machine interaction, including control instruction sending and data query and storage. The lower computer mainly realizes the information collection, the transmission, the control decision generation and the instruction execution; Based on the ZigBee communication between nodes, the design and simulation of 2-D fuzzy logic controller for water and water fertilizer coupling were completed. The key stage of cotton growth was selected as the main research stage. The soil moisture deviation E and the variation rate of soil moisture deviation were designed to control the soil moisture content of 0.5 meters of cotton plant at 60-70%. Two-dimensional fuzzy logic controller of E system with input variable and irrigation time T as output variable; Considering the coupling effect of water and fertilizer, the 2-D fuzzy logic controller of water and fertilizer coupling is designed, and the fuzzy controller is designed. Different water and fertilizer requirements were considered from seedling to emergence stage, seedling stage, flowering and boll stage, and growth stage. The upper and lower limit setting module of the control parameters of water and fertilizer is designed on the upper computer. The fuzzy control query table is generated based on Matlab, and the simulation of fuzzy control is carried out through the Simulink module. The results show that. After 20 s of oscillation, the system tends to be stable, under this condition, the irrigation time needs 150 min. 3) completed the design and implementation of the upper computer and the lower computer hardware configuration. Using Java Web technology to complete the design of host computer and cloud MySQL database. The function module of upper computer software includes: display and query, local and cloud database, parameter setting. Control interface. The hardware and software of the lower computer are designed. 8051F410 single chip microcomputer is selected as the core board of the hardware system. The fuzzy control decision is completed and the soil moisture is collected in real time by each valve control node. Through the data of pipeline flow and solenoid valve opening and closing, the communication between main control and node and node is realized by ZigBee, the operation of solenoid valve is controlled, and drip irrigation is automatically controlled. Finally, the programming of controller program, the selection of components and circuit design are completed. The intelligent irrigation control system based on fuzzy logic is developed. The test results of the sensor and the field test of the control system show that the maximum deviation between the water sensor and the standard detector is 0.5, and the average deviation is 0.27, which indicates that the sensor selection is correct. The control system can open and close the irrigation solenoid valve according to the soil moisture requirement and operate stably and reliably.
【学位授予单位】：石河子大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S562;TP273

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