农田精准平整过程中三维地形实时测量方法研究

为提高农田平整作业过程中平后区域田面地形实时测量精度，本文提出一种农田精准平整过程中三维地形实时测量方法(Real-time 3D terrain measurement, Rt3DTM)。以安装有GNSS双天线和姿态传感器的支撑轮式旱地平地机为地形测量平台，利用卡尔曼滤波器融合GNSS与加速度提高定位精度，通过建立平地铲运动学模型获得支撑轮底点的车体坐标，结合平地铲位姿信息对支撑轮底点进行世界坐标解算，并利用最邻近插值法生成地形图。静态试验表明，Rt3DTM方法能准确解算支撑轮底点坐标，平面测量均方根误差小于10 mm,高程测量均方根误差不大于20 mm。水泥路面试验结果表明，在3组不同车速下测量同一段水泥路面三维地形，与真值的高差均方根误差均小于30 mm。田间试验结果表明，Rt3DTM测量的高程均方根误差为16.5 mm,平整度为16 mm,小于30 mm的高差分布列为95.8%,相比机载GNSS测量方法的均方根误差准确性提高29.5%,平整度准确性提高11.1%,高差分布列准确性提高9.5%。提出的Rt3DTM方法能实时准确地获取平整作业过程中平后区域的地形信息，为无人化农田平...

Real-time 3D Terrain Measurement Method and Experiment in Farmland Leveling

In order to improve the real-time measurement accuracy of field surface topography in the area behind the leveling in the process of farmland leveling operation, a real-time measurement method of 3D topography in the process of farmland precision leveling was proposed.Using a supported-wheel dryland grader installed with GNSS dual antennas and attitude sensors as a terrain measurement platform, the Kalman filter was firstly used to fuse GNSS and acceleration to improve the positioning accuracy and frequency, and then the vehicle coordinates of the bottom point of the supported wheel were obtained by establishing the kinematic model of the grader, and finally the geodetic coordinates of the bottom point of the supported wheel were solved by combining the information of the position of grader and the topographic map was generated by using the nearest neighbor interpolation method.The test verification showed that this method can accurately solve the coordinates of the bottom point of the support wheel, and the root mean square error of the plane measurement was less than 10mm, and the root mean square error of the elevation deviation was not more than 20mm.The test results of cement pavement showed that the root mean square error of the elevation difference between the measured value and the true value was less than 30mm when the three-dimensional terrain of the same section of cement pavement was measured at three different speeds.The field test results showed that the root mean square error of the measured terrain was 16.5mm,flatness was 16mm, and the elevation difference distribution less than 30mm was 95.8%. Compared with the airborne GNSS measurement method, the root mean square error accuracy was improved by 29.5%, flatness accuracy was improved by 11.1%, and height difference distribution column accuracy was improved by 9.5%.The method proposed can obtain the topographic information of the area behind the leveling in real time and accurately during the leveling operation, and provide a basis for the research of real-time path planning of unmanned farmland leveling.