Acquisiton And Analysis Device On The Operation Data Of Agricultural Machinery For Weak Network Environment

In response to the poor wireless communication quality and weak satellite positioning signals encountered by small and medium-sized agricultural machinery during mountain operations in China,this paper investigated and analyzed the means to achieve stable communication transmission and reliable trajectory positioning.It studied a device for agricultural machinery operation data acquisition and analysis that is suitable for weak network environments.With the STM32 series processor as the core,this paper designed hardware circuits for data acquisition and transmission,realized the development of vehicle-mounted hardware systems,and based on satellite,inertial navigation,and odometer positioning,achieves agricultural machinery operation trajectory fitting and area calculation.The research and testing of agricultural machinery operation data acquisition,operation trajectory fitting,and operation area calculation evaluation were carried out in a real application environment.The main research work of this paper includes:(1)To design a hardware system for a device for agricultural machinery operation data acquisition and analysis suitable for weak network environments,this paper analyzed the methods for agricultural machinery operation data acquisition and transmission in weak network environments,and built a hardware circuit with STM32 as the core.The main modules include a main controller module,a data acquisition module,a communication and storage module,a power supply module,and a human-machine interaction module,which are used to collect eight pieces of data(rotary tillage depth,furrow depth,longitude,latitude,odometer,heading angle,pitch angle,and roll angle).(2)To design a software system for a device for agricultural machinery operation data acquisition and analysis,this paper analyzed the positioning and communication methods for agricultural machinery in weak network environments,and adopted the method of automatic switching between satellite positioning and inertial navigation positioning.When the number of available satellites is insufficient,the system switches to inertial navigation combined with odometer positioning.In order to realize data transmission in weak network environments and ensure that the order and authenticity of uploaded data are consistent with the actual situation,the data and timestamp were first saved to the local SD card,and the data in the SD card is automatically uploaded to the cloud when communication is restored.Through the core processor,the sensor is controlled to obtain agricultural machinery operation data,and data acquisition and transmission are realized.(3)To calculate the trajectory fitting and area of agricultural machinery operation in different network environments,this paper calculated the agricultural machinery operation area based on Gauss projection,Kalman filtering,and polygon area method based on latitude and longitude coordinates in the network environment.In weak network environments,the relative position of agricultural machinery is calculated based on the heading angle,pitch angle,and odometer using trigonometric functions.The coordinate points are fitted into a surface by interpolation and grid division,and the area of each small grid is calculated using the Heron formula,thus obtaining the area of the entire surface.(4)To test the functions and performance of the device for agricultural machinery operation data acquisition and analysis,agricultural machinery operation information was collected in a weak network environment,and the test results were comprehensively analyzed and evaluated.For flat farmland,the maximum calculation error of the operation area calculated by the polygon area method is 7.17%.To solve the problem of the inability to accurately measure the actual area of irregular farmland,this paper respectively adopted the method of calculating the standard semi-spherical area and verified the accuracy of the grid method.The surface of the same irregular farmland is fitted and the standard deviation of the area of the farmland and the starting point is calculated respectively by traveling from different starting points,to test the accuracy of the area calculation method.The results showed that the maximum error of the accuracy of the grid method is 8.62%,and the accuracy test standard deviation is 4.71.