Greenhouse Cluster Control System Design And Implementation

The main agriculture greenhouse used in China is plastic greenhouse canopy. The advantage of this kind canopy is low investment and high efficiency, the shortcomings is low automation and high labor force need. Develop economic applicable automatic control system for plastic greenhouse canopy is the active demand in Chinese agriculture. This paper developed this kind control system for greenhouse canopy, and supported by the project "greenhouse cluster control system design" from one company focused in dendrobium candidum planting.First, the features of environment factors and environment adjust equipment are introduced, and then en overall structure of greenhouse cluster control system based on RS485bus is designed.Then, hardware platform is developed, combined with techniques such as sensors, communication and automatic measurement. Design philosophy of universalization, modularization and standardization are also adopted in the development. The hardware platform includes field controller, environment factor collector and electrical system of greenhouse canopy.Software in the system includes PC management software, client application software and local controller software. PC management software based on Lab VIEW in this paper can realize data management, user operation interface, history and real-time curve. Local user can operate the software to check greenhouse environment factor and equipment state, and set control parameters. When sever whether comes, users can also handle the equipment by the software. By client application software, remote users can access local PC and realize remote management of greenhouse cluster. Local controller software takes in charge of auto control and human-machine interface in greenhouse canopy.At last, a temperature and humidity model which is based on heat transfer relations between greenhouse canopy and ouside environment. The model can simulate the relation between environment changes and work state of the equipment. Fuzzy control which simulates manual control is used in this paper. Fuzzy control is of much robust and stability, the performance of the controller is similar with manual control so the goal is achieved.