Development Of Greenhouse Distributed Control System

Confronting with the present need for industrialized greenhouse development, a distributed, cheap and intelligentized control scheme of greenhouses is put forward in this thesis. Then this kind of control system consisted of slave notes of MCU controllers and monitoring server of PC is developed based on RS-485 BUS network.After analyzing characteristic and demand of greenhouse environment control, a control strategy of three control modes is established and some arithmetic of greenhouse environment control are designed. Finally, the distributed greenhouse control system including hardware and software is developed. The hardware is made of multi-function MCU controllers and a RS-485 communication network, while the software made of program of controllers, monitoring and management software and program of communication. The multi-function MCU controllers possessing friendly interfaces for man-machine can work at two modes, i.e. online pattern and offline pattern, and all of them can complete data collecting, disposing, saving and so on and greenhouse actuating equipment are controlled automatically by following them. The controllers at online pattern can receive up-layer configuration parameters from the monitoring server by the method of serial communication. Monitoring and management software developed rapidly by Visual Basic 6.0 and monitoring server can control, manage and maintain as much as 64 control salve notes. Functions of the software are data collecting and saving, controllers configuration, fault diagnose for equipments, environment parameters setting, real-time data refreshing and historical data displaying and printing. Advanced technique of ADO is employed to develop monitoring database system based on MS SQL Server 2000. At the end of the thesis, local debugging experiments and an integrated control effect experiment of greenhouse turn out that the system has met the expected demands.To a great extent, the system of distributed greenhouse control will promote the transition of greenhouse agriculture from demonstrated agriculture to industrialized agriculture in present China. It is a beneficial try for product development of current greenhouse control system. Remarkably, the development process of the entire system process a high reference value for product development of greenhouse control system or related product development.