CAJ | 학술논문

为了精确测量拖拉机在农田作业时的作业面积，以评价拖拉机的作业效率。该文选用双星定位（GPS 卫星和伽利略卫星）接收机采集定位数据，采用自适应卡尔曼滤波算法提高接收机单点定位精度，利用高斯投影算法将GPS接收机采集经纬度转化成平面坐标来计算面积。选用回耕法、梭形耕法、套耕法3种方法旋耕地块，利用安装拖拉机上的GPS识别出作业轨迹，利用图像处理计算3种方法的有效作业面积、实际作业面积和重漏耕面积。试验表明：卡尔曼滤波提高了GPS单点定位精度；面积测量相对误差为2.09%；地块1（回耕法）漏耕率为14.29%，重耕率为6.19%，地块2（梭形耕法）漏耕率为10.72%，重耕率为5.54%，地块3（套耕法）漏耕率为1.80%，重耕率为6.82%。随测量面积增加，测量精度越高；套耕法效率最高，梭形耕法其次；回耕法的漏耕率最大，作业效率最低。
위료정학측량타랍궤재농전작업시적작업면적，이평개타랍궤적작업효솔。해문선용쌍성정위（GPS 위성화가리략위성）접수궤채집정위수거，채용자괄응잡이만려파산법제고접수궤단점정위정도，이용고사투영산법장GPS접수궤채집경위도전화성평면좌표래계산면적。선용회경법、사형경법、투경법3충방법선경지괴，이용안장타랍궤상적GPS식별출작업궤적，이용도상처리계산3충방법적유효작업면적、실제작업면적화중루경면적。시험표명：잡이만려파제고료GPS단점정위정도；면적측량상대오차위2.09%；지괴1（회경법）루경솔위14.29%，중경솔위6.19%，지괴2（사형경법）루경솔위10.72%，중경솔위5.54%，지괴3（투경법）루경솔위1.80%，중경솔위6.82%。수측량면적증가，측량정도월고；투경법효솔최고，사형경법기차；회경법적루경솔최대，작업효솔최저。
The rapid development of modern agriculture in China has put forward higher requirements for agricultural machinery operation. In terms of area measurement, GPS (global positioning system) has become an important measuring tool, completely changed the traditional mode of operation, liberated the labor force, and improved the operation efficiency. Field operation is still basically in the stage of manual operation, so it is inevitable that there is much repetitive operation and missing operation. How to accurately measure the area of operation, this is a necessary issue. In this paper, the adaptive Kalman filter was used to improve GPS positioning accuracy for accurately measuring the tractor operation area. The adaptive Kalman filtering algorithm was mainly to solve the problem of the degradation of the system’s filtering accuracy and the divergence of the system in the case of noise statistics being unknown or not accurate. In order to achieve the system noise estimation of adaptive filtering, we used the covariance matching technology and the Kalman filter residual error to realize the algorithm. In this research, the LABVIEW software was used to get latitude and longitude data of GPS receiver. And then the Gauss projection algorithm was used to change the longitude and latitude data into plane coordinates to calculate the area. To test and verify the influence of different ways of operation on the operation efficiency, back tillage, spindle tillage and alternative plough method were chosen. Firstly, this research used MATLAB to identify the operation trajectory, then used different color to show the area of operation, and used the image processing method to calculate the effective operation area, the actual operation area, and the missed and repeated tillage rate, which were used to evaluate the operation efficiency of the tractor. In order to verify the feasibility of the algorithm, the accuracy of single point positioning and the accuracy of area measurement were tested. The single point positioning experiment showed that the Kalman filter improved the accuracy of GPS single point positioning. The numerical changes at thex andy direction before filtering had relatively big fluctuation, and became flat after filtering. The mean value of coordinates changed after filtering, and the mean square error became smaller. Thex coordinate reduced from 0.06317 to 0.05807 m after filtering, and they coordinate reduced from 0.07901 to 0.04097 m after filtering. In the test of GPS area measuring precision, which was the preparation for its work in the measurement of field area, this research used the GPS to measure some regular and irregular figures. The result showed that the relative error of area measurement was 2.09%. Finally, the field experiment was conducted. The result showed that Block 1 missed tillage rate was 14.29%, and repeated tillage rate was 6.19%; Block 2 balk rate was 10.72%, and backset rate was 5.54%; Block 3 balk rate was 1.81%, and backset rate was 6.82%. With the measurement area increasing, the measurement accuracy was higher. The most efficient farming method was alternative tillage, and the second was spindle tillage. Back tillage’s balk rate was the highest, and its operating efficiency was the lowest. Image processing method was used to calculate the backset and balk acreage in this paper. Different colors were used to display normal area, repeated tillage area and missed tillage area, through which it could visually display missed and repeated tillage locations, and then calculate the working efficiency. We can use this method to guide the actual agricultural production operation, and select the operation mode with high efficiency.