| Greenhouses,as a key component of modern agriculture,can provide the most suitable environment and resist seasonal changes and harsh climate conditions from the outside world.In order to improve crop growth conditions,people continuously conduct in-depth research on greenhouse environmental factors,such as temperature and humidity,in order to achieve the best environmental regulation effect.Due to the large hysteresis,complex nonlinear characteristics,and multi input multi output characteristics of greenhouse gases,it is extremely difficult to establish an accurate mathematical model.In order to effectively improve the greenhouse environment,we must combine traditional control technologies with advanced control ideas in order to better achieve the goal of optimizing greenhouse control.Although it is not necessary to ensure extremely high control accuracy for greenhouse environmental parameters,the stable adjustment and control of greenhouse environmental parameters is a prerequisite for ensuring high and stable crop yields and improving economic benefits.Studying remote greenhouse environmental monitoring and energy-saving technologies is very important for us,as it not only has theoretical significance but also is very practical.Based on the above background,this article discusses the issue of greenhouse environmental control methods and designs a greenhouse remote monitoring strategy based on Lo Ra technology.At the same time,taking temperature and humidity as two important environmental variables as research objects,a greenhouse temperature and humidity control system based on fuzzy predictive control was designed to achieve target value tracking control of greenhouse temperature and humidity.The temperature and humidity of the greenhouse were controlled within the suitable production range,laying the foundation for further exploration of more advanced control decisions and enriching the regulation methods of greenhouse environment in the future.The main research content is as follows:(1)This article delves into the basic principles of conventional PID control,fuzzy control,and predictive control.Based on the characteristics of the greenhouse environment,the greenhouse temperature and humidity control system is analyzed,providing a strong theoretical basis for further improving the greenhouse temperature and humidity control system.(2)A small experimental greenhouse is taken as a mock object to establish a mathematical model,and the temperature and humidity transfer function of the experimental greenhouse is obtained by fitting the unitary regression equation.The fuzzy predictive PID control system model is designed and built by using the simulation tool in Matlab software.The temperature and humidity target value controller that optimizes the quantitative factors and correction coefficients of the fuzzy PID with predictive control algorithm is designed for the model.Thus improving the tracking accuracy and accuracy of the actual temperature and humidity of the greenhouse against the set temperature and humidity values.(3)Exploring remote wireless monitoring technology,based on the basic technical advantages of the Lo Ra module,the communication design for the Lo Ra sending end and Lo Ra receiving end has been mainly completed in the communication system.Introduced the software and hardware implementation process of the Lo Ra wireless communication module in the communication system.Verified that the communication system based on Lo Ra fully meets the command and data transmission requirements of the greenhouse environment.(4)Build a small experimental greenhouse monitoring platform,use PLC as the control core to design the greenhouse temperature and humidity control system.Based on the overall requirements analysis,the overall scheme design was carried out.The implementation of the system is divided into three steps: first,configure the PLC hardware,then conduct programming debugging,and finally complete the wiring work of the executing mechanism and sensors.We used King View software to design the configuration monitoring interface for the upper computer during the development process.The logic and feasibility of the system have been proven through operational verification,data collection,and comprehensive comparison. |
