The Research Of Greenhouse Environment Monitoring & Controlling System Based On Microcomputer And Fieldbus Network

With the rapid development of sensor computer and communications technologies, the design of intelligent monitoring & controlling systems for greenhouse has become one of the R&D focuses in the field of structured agriculture. The paper is dedicated to the research of greenhouse environment monitoring & controlling system based on microcomputer (MCSM) and fieldbus network.Firstly, this paper introduced the current status of MCSM research in the world with the emphasis on the significance of developing MCSM with independent intellectual property right in this country. Then, the characteristics of various environment parameters in greenhouses are analyzed in detail, and their physical models are set up as the basis of MCSM designing. The substantial part of this paper is to design and develop intelligent temperature & humidity sensor systenu the MCSM and PCS interface in the greenhouse.1. Compared with conventional sensors, the intelligent temperature & humidity sensor system is made up of traditional sensor combined with embedded microcomputer which has functions of signal detection,preconditioning,processing,memorizing,logical reasoning. On top of its conventional activities of signal magnification, reshaping , filtering , sampling , A/D transformation and scale switching, the intelligent sensor system can perform kinds of advanced operations such as on-line storage of parameters, real-time data processing,self-diagnosing of the system and so on. Because of its communication interface with PCS, it serves as intelligent plug & play network sensor.2. The microcomputer-based greenhouse monitoring & controlling system has been developed around an ATMEL microcontroller which is reinforce by multiplex A/D sampling module; large volume data on-line storage module ; real-time clock module ; keyboard & display man-machine interaction module ; system monitoring module and communication interface module and so on.3. Field controlling system technology has been adopted in the design of large greenhouse monitoring & controlling system in the present project. The paper introduces the concepts of PCS , in particular CAN bus and the development of a microcomputer-based greenhouse field controlling system on the basis of CAN.At the end of this paper, some shortcomings and tentative solutions of the present design are summarized for further improvement in the future.