Authors

Abstract

How to accurately and efficiently measure the profiles of the terrain on which agricultural machines operate has been an ongoing research topic. In this study, a surface profiling apparatus (profiler) was developed to measure agricultural terrain profiles along parallel tracks. The profiler is mainly composed of sensor frames, an RTK-GNSS system (Real Time Kinematics-Global Navigation Satellite Systems), laser sensors, an Inertial Measurement Unit (IMU) sensor and a data acquisition system. Along with a full description of how the terrain profiles were produced, a methodology to compensate for the tractor motion was included in the sensor data analysis. In field profiling validation, two trapezoidal bumps with known dimensions were used to assess the ability of the terrain profiler to reproduce the vertical profiles of the bumps, resulting in root mean square error (RMSE) of 3.6-4.7 mm and 4.5-5.1 mm with profiling speeds of 1.02 and 2.56 km/h, respectively. In addition, a validation test was also conducted on an asphalt road by profiling a flat road with the measuring wheels of the profiler rolling on the flat section but with the tractor wheels driving over a trapezoidal bump to excite the tractor pitch and roll motion. The measured profiles then also exhibited a flat road, which showed the ability of the profiler to remove the tractor motion from the profiling measurements.

Abstract in Chinese

如何准确、高效地测量农业机械所接触的农田地面不平度一直是研究者们关注的问题。本文设计了一种可并排测量农田地面不平度的装置，主要由传感器架、RTK-GNSS系统、激光传感器、IMU传感器和数据采集系统等部分组成。在数据分析中，除了对地面不平度的生成进行了完整描述外，提出了一种补偿拖拉机运动的方法。农田试验中，利用两个尺寸已知的梯形凸台检验不平度测试装置再现凸台垂直剖面的性能，当测试速度分别为1.02和2.56 km/h时，不平度均方根误差范围分别为3.6-4.7 mm和4.5-5.1 mm。另外，在沥青路面上也开展了验证试验，方法是对平坦沥青路面进行不平度测试，使不平度测试装置的地轮在平坦路面上滚动，而拖拉机车轮经过一个梯形凸台，以激励其产生俯仰和侧倾运动。测量的不平度结果依然反映的是一条平坦的路面，证明了不平度测试装置从测量值中去除拖拉机运动成分的有效性