| The increasing tension of land resources and the change of environment and climate restrict the traditional agricultural planting methods,and many scholars began to study the methods of soilless cultivation.Soilless cultivation has brought good news to food crop growers and consumers.This cultivation method does not use traditional soil as the planting medium,and intensive management can be used for large-scale production.There is no need to spray pesticides during crop growth,which ensures food safety.However,nowadays,the research on soilless cultivation technology at home and abroad is mostly limited to large-scale tiled cultivation;Most of them still use substrate for cultivation,and the substrate is not reusable,resulting in higher costs;Or only manually open the water pump and valve to start water filling and return operation,which is tedious;Or under the automatic water feeding mode,the automatic and manual modes of nutrient liquid water feeding can be switched conveniently;Power consumption is huge,causing greater pressure on the power grid;The way to judge the growth and maturity of crops can only rely on the experience of relevant personnel,and can not automatically identify the various drawbacks of crop growth through algorithms and many other problems.Based on the above,this paper studies and designs a kind of soilless cultivation container type culture stand and its intelligent control system.This topic focuses on the biological characteristics of butter lettuce,a popular vegetable variety in soilless culture,and carries out analysis and evaluation.The main work is as follows:Four soilless cultivation racks and their supporting intelligent control systems are built in kind.The environmental factors suitable for its growth were analyzed,and the effects of temperature and humidity,carbon dioxide concentration,and light intensity on the growth of butter lettuce were analyzed.A fuzzy PID controller that can quickly adjust environmental variables was designed,and the effect was significantly better than the conventional PID controller.The structural design of soilless planting frame is carried out,and the pipeline layout is completed,which can make the backwater on the nutrient solution go its own way without interfering with each other,and can easily switch the electrical automatic and manual modes.Through calculation,a water pump with a suitable lift is selected,and solar energy power,a clean energy,is introduced to reduce the consumption of the power grid.The circuit diagram and wiring diagram are designed,and the corresponding electrical control box is built,which realizes the sequential feeding and returning of nutrient solution.The reasonable on-off sequence ensures the safety of electrical appliances.The STM32 development board and sensor technology are used to collect the environmental factors in the container where cream lettuce grows.The data is transmitted to the upper computer through the serial port for real-time monitoring.The data is also input as the feedback data of fuzzy PID,and used to adjust environmental variables.The maturity collection system of cream lettuce based on machine vision is introduced,and the algorithm is used to automatically identify the maturity status of leaf spread and plant height of cream lettuce,and the maturity of cream lettuce is classified according to the characteristics of this algorithm. |
