Experimental Study On Temperature And Humidity Environment Control In Plant Factory With Artificial Light Source

Plant factories as the highest level of facility agriculture,are one of the most dynamic and potential fields in the process of agricultural industrialization to absorb and apply high-tech achievements,and represent the future development direction of agriculture.The key to the sustainable and healthy development of plant plants is to break through these bottlenecks,such as high initial construction cost,high energy consumption of light source and air conditioning,and low economic benefit.Environment control technology is the core of the plant factory production technology,is a contemporary agriculture biology,environmental science,the integrated application of computer control and management science,is a comprehensive adjustment and control of environmental factors of technology,it's different for the growth of crops,breeding a comfortable environment,to achieve energy saving system running at the same time.In this paper,the environmental mechanism model of plant plant was established,the environmental parameters affecting temperature and humidity were identified by the random deep forest algorithm,and the environmental parameter controller was designed and applied in plant plant by the multivariable decoupled internal model control method.The main contents are as follows:(1)The temperature and humidity environmental mechanism model of a typical plant plant with artificial light source was constructed,and the random forest theory was put forward to identify the parameters of environmental temperature and humidity model.Based on the theory of energy balance and mass balance theory,the establishment of a typical artificial light type plant factory temperature and humidity environment mechanism model,puts forward the theory of random forests for temperature,humidity,identifying the parameters obtained for practical model,control temperature and humidity environment to affect the internal temperature and the humidity of the main environmental parameters.(2)Establish the dynamic nonlinear mathematical model of temperature and humidity control system and the transfer function matrix of the control system,and determine the control strategy after decoupling the temperature and humidity system.The dynamic nonlinear model of temperature and humidity control system is determined,and the model is verified and analyzed.The accuracy of the model is determined by comparing the output value of the system with the measured value of the actual steady-state operating point in the field.The transfer function matrix of temperature and humidity control system of plant plant plant based on artificial light source was established.The relative regularization gain matrix and coupling index were used to decouple the temperature and humidity dynamic system,and the decoupled control strategy of the temperature and humidity system was established.(3)A multivariable decoupled internal model control method of setting a filter in the feedback channel is presented,and the process of internal model control is simulated and verified.Based on the theory of internal model control,the environmental controller is designed to solve the coupling problem of temperature and humidity environment and the time delay problem.The constraints on the time delay and the number of non-minimum phase zeros of each element in the decoupled controller are discussed respectively.A multivariable decoupled internal model control method is proposed to set the filter in the feedback channel.With static working point when A dynamic system of environmental physical parameters and test parameters,for example,the process of internal model control for resistance to external disturbances condition simulation,system response speed conditions,working condition of system stability,the simulation and test system in the condition of output signal change situations timely tracking and the ability to overcome the external disturbance.(4)Field control tests of temperature and humidity under both steady and variable conditions were carried out in plant plants with artificial light source.The experiment of temperature and humidity control in plant plant with artificial light source can be divided into two conditions: steady state and variable state.The control effect can be explained by the actual operation curve.Through the verification test,the indoor temperature is controlled by the air supply flow,indoor humidity is controlled by the moisture content of the air supply,and the temperature is controlled by the cold water flow.The internal model controller has stable working performance,good decoupling effect of the control system,and good set value tracking and disturbance resistance performance,which can meet the production requirements of plant factories.