Application Research And Design Of Intelligent Irrigation System Based On LoRa Agricultural

Agricultural irrigation is a key behavior to maintain normal production activities of crops and plays an important role in increasing crop yields.China is a large agricultural country.The traditional artificial flood irrigation method has caused serious waste of water resources due to problems such as control accuracy and low real-time performance,and has also restricted the sustainable development of agriculture.In order to solve the above problems,combining the advantages of sensor technology,long-distance wireless transmission technology(Long Range,LoRa)and fuzzy control theory,a smart agricultural irrigation system based on LoRa was designed.This system is mainly composed of measurement and control subsystem,transmission subsystem and remote master control management subsystem.The main research work of this paper is as follows:1.In the measurement and control subsystem,the design of collection node and execution node are mainly completed.The main task of the collection node is responsible for the collection of soil moisture and environmental parameters around the crop.It is composed of soil moisture sensors and small meteorological stations.The main task of the execution node is responsible for the regulation and control of soil moisture.In order to improve the anti-interference ability of the node circuit and respond to the call of the national environmental protection agriculture,some circuits have been optimized.A rechargeable power circuit,an isolated AD acquisition circuit,an isolated 485 automatic transceiver circuit and an optocoupler isolated relay control circuit are designed.Aiming at the problem of low measurement and control efficiency caused by the large number of measurement and control equipment in the irrigation system in large-scale farmland application scenarios,the data processing scheme of the digital bus was designed based on the data collection and return mechanism of a single bus.2.In the transmission subsystem,the design of LoRa terminal and LoRa gateway are mainly completed.The LoRa terminal is mainly responsible for data transmission between the measurement and control subsystem and the LoRa gateway,and the LoRa gateway is mainly responsible for data transmission between the LoRa terminal and the remote main controlmanagement.Aiming at the problems of large data aggregation delay and high energy consumption of nodes,a low-power data aggregation scheme is designed based on the basic technical advantages of LoRa module.The scheme adopts a star network structure and a regular hexagonal structure to deploy LoRa terminals.The introduction of data interaction protocols based on state machines improves the speed of data processing,and through the adaptive adjustment mechanism of data transmission rate and time division multiplexing Multi-channel data upload method to reduce the energy consumption of data transmission.Through test and analysis,the LoRa module can work steadily for a year under the conditions of an operating frequency of 470 MHz,a spreading factor of 12,and a communication bandwidth of 62.5KHz.3.In the remote main control management subsystem,the visual display,storage,analysis and prediction of the aggregated data are mainly completed.Aiming at the problems of time-consuming,low water resource utilization rate and large overshoot in the traditional irrigation,an intelligent irrigation strategy based on the winter wheat irrigation model in northern Anhui was designed.Firstly,a fuzzy controller of Mamdani type was designed using fuzzy control theory.The controller is mainly used for fuzzy reasoning of the irrigation time of the system.Secondly,combined with the improved crop transpiration calculation formula and soil penetration model,a soil moisture prediction model based on the change function of soil water content was established.The comparison between the actual value and the predicted value verifies that the model can achieve satisfactory prediction results.Finally,MATLAB was used to simulate the intelligent irrigation strategy,and compared with the traditional PID control,the irrigation system with this strategy was obtained.It has the characteristics of short response time,small overshoot and quick start.In summary,the intelligent agricultural irrigation system designed in this paper has the advantages of low power consumption,good stability,fast response,and not obvious overshoot.It provides an efficient and accurate irrigation scheme for the agricultural production field.Improving the current status of agricultural irrigation has extraordinary significance and has broad application prospect.