Study On The Usability Of The Greenhouse Environment Monitoring & Control System And Its Realization

Greenhouse is a kind of construction with its space enclosing structure totally or partly composed of daylighting covering materials,which enable growth of plants that do not adapt to cold climates and open-ground conditions.The greenhouse monitoring and control technology featuring environmental controllability plays a vital role in the automation and high-efficiency operation of greenhouse production.The application and research of greenhouse monitoring and control systems in China have been undergoing a transcending process,from the initial phase of digestion,absorption and simple application to the current phase of practical and comprehensive application.Meanwhile,the application in China has,however,been facing this reality: advanced systems are only applied in greenhouses of governmental research institutes and large enterprises;as of traditional greenhouses,there are only simplified control systems available for a vast number of farmers and common users,and in some cases,only manual control available. The underlying reasons for this phenomenon are as follows.First,the current break-even point of agricultural facilities precludes the application of high-cost technologies.and systems in China.Second,common users in China do not have the appropriate background education to meet the requirements of advanced systems,making even harder the acceptance and implementation of those technologies and systems.Third,the current China's agricultural production environment and the traditionally extensive management both contribute to the special requirement of firmness and durability on the agricultural facilities.Therefore,it is apparent that the greenhouse monitoring and control system discussed herein is not applicable for common users,resulting in the awkward situation that operation of monitoring and control systems still maintains the level of research demonstration and have not yet been widely implemented.The applicability of greenhouse monitoring and control systems is investigated in this project.Definition of the applicability,analyses of the design and evaluation of applicable systems,and thereafter the methodology of establishing design and evaluation of applicable systems are presented.The investigation includes the following six aspects:1) Survey of three types of greenhouse users(scientific research institutes,enterprises and farmers) in three cities(Quzhou,Lishui and Jiaxing) in Zhejiang province.Knowledge of the application of greenhouse monitoring and control systems in those areas and analyses of user features and requirements thereof. 2) Applicability analyses of greenhouse monitoring and control systems based on the theory of Usability Engineering(UE).Specific definition and attribute analyses of the applicability of greenhouse monitoring and control systems.3) Analyses of design principles of applicability of greenhouse monitoring and control systems.Establishment of corresponding methodology.4) Analyses of evaluation method of applicability of greenhouse monitoring and control systems.Illustration of the determination of the evaluation system,weight of every evaluating indicator and the process of modeling and application.Finally,building of a comprehensive model for applicability evaluation of greenhouse monitoring and control systems.5) Analyses of selection of key technology for applicability design of greenhouse monitoring and control systems.Comparative analyses of existing host computer systems(IPC, general PC)and embedded special-purpose computer systems.An improved solution proposed accordingly;Comparative analyses of existing bus platforms(485 bus,CAN bus) and the Ethernet.Appropriate cable systems recommended;Comparative analyses of existing short-range wireless communication technologies.Applicable wireless solutions proposed accordingly.6) Design of functional modules of the monitoring and control system,including embedded special-purpose monitoring and control apparatus modules,smart network sensor modules, smart network actuator modules,NCAP modules and ZigBee-based wireless modules. Establishment of Ethernet-based cable solutions and ZigBee-based wireless solutions. Applicability evaluations of traditional PC-based systems,Ethernet-based cable systems and ZigBee-based wirelesssystems,on the basis of the applicability evaluation model of greenhouse monitoring and control systems.Comparison of the applicability of the three types of monitoring and control solutions presented.