【摘要】 针对集装箱植物工厂体积小、可控性强的特征,利用最适化控制原理,针对控制成本低、控制效果好的营养液管理、人工补光、箱内环境温度3个因子,基于可编程控制器建立了一套自动控制系统。该系统将人机交互触摸屏作为上位机,采用开关量控制原理进行营养液循环和LED周期补光的管理;利用闭环PID控制原理,进行箱内温度的调节,可实时监测集装箱内部温度和营养液特征变化过程。同时,采用人机友好的工作方式,通过调用管理者输入的各类参数,自动进行控制决策并执行控制程序。试验验证表明:该系统能够根据人工设定的控制参数,实现营养液分层循环、定时供液;能够按照设定时间自动控制LED光源的闭合/断开,实现不同光照周期的转换;能够实时监测温度,并根据目标温度调节制冷/供暖机构,使集装箱内温度持续保持在适宜作物生长的范围内。参照系统在集装箱植物工厂内使用情况,可以确定本系统成本低、运行稳定,能够满足集装箱植物工厂中农作物管理需求。更多还原

【Abstract】 For the Container- type Plant Factory,an automatic control system,which contains the cycle of nutrient solution,the artificial light and the tempreture inside,was established. This system aims at the feature of small volume and easy control of container. Simultaneously,sues three low cost and better effect factors as controlled object,according to optimal control theory. System is developed,based on the Programmable Logic Controller( PLC) and a touch screen is used as the master computer. Programs make use of swich signal control principle to manage the nutrient solution and LED. At the same time,adjust temperature inside container on the basis of closed- loop PID control. The screen will monitoring the whole process of the real- time changes about the environment inside and the nutrient solution. Meanwhile,control policy is determined automatically through various parameters invocation and computer programs are executed by mans of human- machine coordination. The experiment verified that the system could implement the layered cycle of the nutrient solution and regularly supply according to the control parameters manually set. And it could implement the conversion of different photoperiod by turning the LED on and off automatically,referring the time managers given. In addition,the tempreture could be controlled in a range which is suitable for the growth of plants by adjusting the temperature regulates organization. Thus,this low- cost and reliable control system could meet the demands crops need in Container- type Plant Factory.更多还原