目的 低成本实现南方中小型田块中农业机械田间精确定位，降低农机操作人员劳动强度、提高农机作业效率。方法 采用超宽带(Ultra wide band，UWB)技术对作业机械进行实时定位，通过位置解算算法，得到定位标签的三维精确位置坐标；利用位置校正算法，修正作业机械车身倾斜引起的田间定位误差；设计基于AB线的路径规划算法，实时规划作业路径并计算作业偏差；通过可视化人机交互界面为农机操作人员提供实时辅助驾驶信息。结果 水田环境中，分别以0.5、1.0和1.5 m/s的速度沿规划路径行驶时，系统平均横向定位偏差均小于7 cm；当行驶速度大于1.0 m/s时，利用位置校正算法平均横向定位偏差降低了52.79%，标准差降低了49.82%，最大横向定位偏差降低了50.04%。搭载辅助导航系统进行田间插秧试验，各行作业轨迹与自身行拟合直线的平均横向偏差为5.90 cm，标准差为3.64 cm；各行作业轨迹与其规划直线路径的平均横向偏差为6.98 cm，标准差为4.95 cm。结论 辅助导航系统具有较高的定位精度和良好的稳定性，成本低且通用性强，能够满足南方中小型田块中农业机械田间作业要求。研究结果可为农业机械田间精确定位提供参考。
Objective To achieve low-cost agricultural machinery field positioning for small and medium-size farmland in southern China, so as to reduce labor intensity for machine operator, and improve the working efficiency of agricultural machinery. Method This system utilized ultra wide band (UWB) technology to accomplish real-time positioning of operating machinery, and the precise three-dimensional coordinates of the positioning labels were calculated using the localization algorithm. The position correction algorithm was then used to correct the field positioning error resulted from the body tilt of working machinery. A path planning algorithm based on AB line was designed to plan the operation path and calculate the operation deviation in a real-time manner. This system provided real-time driving assistance information for agricultural machinery operators through the visual human-computer interaction interface. Result In the paddy field environment, the average lateral deviations were less than 7 cm when agricultural machinery traveled along the planned path at speeds of 0.5, 1.0 and 1.5 m/s, respectively. When the travel speed was above 1.0 m/s, the average lateral deviation, the average standard deviation and the maximum lateral deviation were reduced by 52.79%, 49.82% and 50.04% respectively, based on the position correction algorithm. When the agricultural machinery equipped with the auxiliary navigation system was tested in the field transplanting experiment, the average lateral deviation between each operating trajectory and its fitting line was 5.90 cm and the average standard deviation was 3.64 cm. The average lateral deviation between each operating trajectory and its planned path was 6.98 cm and the average standard deviation was 4.95 cm. Conclusion The auxiliary navigation system has high positioning accuracy and good stability, as well as low-cost and strong universality, which can address the requirements of agricultural machinery field operation for small and medium-size farmland in southern China. The research results can provide a valuable reference for precise positioning of agricultural machinery in the field.