多约束情形下的农机全覆盖路径规划方法

Full Coverage Path Planning Method of Agricultural Machinery under Multiple Constraints

为满足自主作业农机自动导航作业的需求并优化农机作业效率,在处理多种车辆转弯方式约束和农业地块约束的基础上,基于模拟退火算法提出一种混合规则路径规划方法。在多种作业约束处理方面,引入了农机转弯代价邻接矩阵来量化农机地头转弯方式的影响,通过采用内缩改进的道格拉斯普克(Douglas-Peucker)拟合算法与求解采样点的最小凸包分别处理地块边界及障碍物边界。在使用角平分线的平行偏移法求得转向预留地块后,以转弯代价最小为优化条件对多种形状地块进行了最优作物行生成。在农机遍历顺序方面,利用模拟退火算法求解得到最优路径集,并通过单元拆解及合成的方式求解全覆盖遍历顺序,解决了传统规则遍历走法适应性差和大规模农机作业时经典模拟退火算法易陷入局部最优解的问题。实验表明,本文方法所得路径平均作业覆盖率达90.78%,平均作业占空比达85.10%。在同等作业条件下,利用本文方法所得路径比传统规则路径最多可节约距离消耗30.3%,比模拟退火算法所生成路径节约6.9%。说明本文规划算法可在多种约束下对农机进行作业路径规划,且具有较好的规划效果。

In order to meet the requirements for automatic navigation operations and optimize the efficiency of agricultural machinery operations,a path planning algorithm formed by mixed rules was proposed based on simulated annealing method,after dealing with the constraints of various turning methods and agricultural plots.In terms of multi-constraint processing,the adjacency matrix of agricultural machinery turning cost was introduced to quantify the influence of different turning modes,and the block boundary and obstacle boundary were respectively dealt by using improved Douglas-Peucker fitting algorithm and the minimum convex hull of sampling points was solved.After the reserved area for turning were obtained by using the parallel migration of angle bisectors,the optimal crop rows of multi-shape parcels were generated in order to reduce the cost of turning.In traversal order of agricultural machinery,full coverage traversal order was formed by disassembling crop rows into units,solving the optimal units with simulated annealing method and assembling to a whole path.The algorithm solved the problem that traditional planning methods were hard to adapt to different conditions and classical simulated annealing method fell into local optimal solution easily in large scale planning.The experiment results showed that coverage of the paths obtained by proposed method was up to 90.78%in average and the average duty cycle was 85.10%.Under the same conditions,the proposed path can save up to 30.3%distance consumption compared with the traditional path,and 6.9%compared with the path formed by simulated annealing algorithm.The results showed that the proposed algorithm can plan the operation path for agricultural machinery under various constraints and reach a better planning effect.