基于GPS的农田坡面平整技术与试验

设计了一种基于GPS的农田土地坡面平整系统,该系统由自主差分GPS接收设备、车载式工控机、控制转换器、液压系统、铲运装备等几部分硬件组成,以Visual C++60为系统软件开发环境；系统可对农田进行动态地势测量及坡面平整作业．首先,将GPS接收设备安置在铲运设备上,利用拖拉机牵引铲运设备对农田进行动态蛇形测量,并通过相应的校正算法对测得的GPS数据进行误差校正;然后,根据校正后的数据,对农田进行三维地形成图及坡面建模,得到农田坡面期望高程;最后,将实时接收的农田实际高程与坡面期望高程进行比较,通过控制转换器输出液压控制信号驱动铲运设备进行挖填土方的平地作业．在田间试验条件下,根据农业工作者要求对纵向长度为180 m的地块进行1／1 000纵向坡降的平地试验,结果表明,平地后标准偏差值在5 cm左右,坡低的平均相对高程约为4062 m,坡顶的平均相对高程约为4078 m,坡面高差为16 cm,其理论坡面高差为18 cm,有效改善了农田坡面地形．

GPS based land slope leveling technique and its implementation

In order to improve the land slope leveling accuracy and achieve high quality irrigation, a GPS Based land slope leveling system was developed. The system consists of GPS receiver, vehicle mounted IPC, control conversion module, hydraulic system and earth moving equipment. And the software of the system is programmed in Visual C++ 6.0. The system can measure farmland topography instantaneously, and perform land slope leveling. First of all, the GPS receiver is installed in the earth moving equipment to measure farmland topography in a serpentine path; the topography data are corrected with a correction algorithm to reduce the error. Then, a three dimensional topography is vi sualized and a farmland slope model is established by using the corrected data to obtain the expected slope reference elevation. Finally, the real time elevation is compared with the slope reference elevation, the comparison result is input to the control conversion module, and its output signals are used to drive the hydraulic system for leveling the land. The land slope leveling implementation was carried out in a land with 180 m longitudinal size and 1/1 000 longitudinal slope. The results showed that the standard deviation is about 5 cm, the mean elevations at top and bottom of the slope is about 40.62 m and 40.78 m, respectively, causing a 16 cm difference in elevation compared with 18 cm theoretical differences. Thus, the preliminary goal has been achieved.