Design And Application Of The Precision Environmental Control System For The Artificial Light Seedling Raising

Robust seedlings are the foundation of high and stable yield of crops.Modern agriculture widely adopts factory centralized seedling raising technology.At present,most of the seedling companies in China are still in the stage of artificial management.According to the personal seedling experience of the administrator,they irrigate,supplement light and heat the seedlings.Under such traditional seedling management,not only lack of rigorous scientific theoretical basis,but also waste a lot of human resources.In this paper,ZigBee technology is used to design the precision environment control system of all artificial light seedling,and the design of precision environment control system of all artificial light seedling and the optimization of seedling environment parameters are carried out.The main research is as follows:1.The design of precision environment sensing system for all artificial light seedling.The temperature,humidity and illuminance sensor are used to collect the environmental parameter information,and send the parameter information to the main controller of the system.The temperature measurement accuracy of the sensor is≤0.3℃,the humidity measurement accuracy is≤2%,and the illuminance measurement range is 0～120000 lx.2.The design of precise environment control system for all artificial light seedling.The control system consists of temperature control system,lighting system and humidity control system.When the sensor temperature is greater than the upper limit temperature or lower than the lower limit temperature,the air conditioning relay in the corresponding room will be opened;when the sensor temperature is within the set temperature threshold,the relay will be closed.When the sensor humidity is less than the lower limit humidity,the humidifier relay in the corresponding room will be opened;when the sensor humidity is greater than the set upper limit humidity,the relay will be closed.When the sensor illuminance is less than the lower limit illuminance,the LED fill light relay in the corresponding room will be on;when the sensor illuminance is greater than the set upper limit of illuminance,the relay will be off.3.The software interface design of the precise environment control system for all artificial light seedling.The interface function has four modules:homepage,current status,address setting and threshold setting.The function of"home page"is used for login of administrator account.Current status is used to display the current parameter information of seedling environment.Address settings are used to control zone binding terminal devices.Threshold setting is used to set the threshold value of relevant environment parameters.4.The application of precision environment control system for all artificial light seedling.Under the normal operation of the control system,through the LED fill light experiment,the frequency and duty ratio of LED fill light were obtained.L₉（3⁴）was used as an interactive orthogonal experimental design.The experimental results showed that when the duty ratio was 25%～50%,it could promote the growth of pumpkin seedlings.The optimal light conditions were:frequency 1 Hz,duty ratio50%,and had significant energy-saving effect.