基于改进蚁群算法的农田平地导航三维路径规划方法

为解决农田平地机无人驾驶作业时缺乏局部规划，进而实现平地路径在线调整的问题，以平地作业土方合理运卸且路径最短为目的，提出了一种基于改进蚁群算法的农田平地导航三维路径规划方法。基于农田三维地势模型，采用改进的蚁群算法规划三维路径：以平地作业土方运载为决策方向，建立新的路径搜索节点，对比平地机作业时平地铲运载土方量和经过栅格计算所需的挖填土方量，根据土方运载任务设置信息素更新规则和启发函数，获取农田平地的最佳三维路径；基于平地机的运动学模型，设置农田平地机转向约束条件，根据约束条件对路径进行平滑优化，并建立三维路径规划的效果评价标准。仿真结果表明：相比于原始蚁群算法，该方法的路径规划效果评价指标提高33.3%以上，可以更好地指导农田平地机实现局部平地任务，而且大大缩短了路径生成时间和路径长度，使路径更为平滑，更适用于辅助农田平地的自动导航作业。

Three Dimensional Path Planning Method for Navigation of Farmland Leveling Based on Improved Ant Colony Algorithm

In order to solve the problem of land grader in unmanned operation lacks local planning to realize on-line adjustment of leveling path, a three dimensional path planning method for automatic navigation of farmland leveling based on improved ant colony algorithm was proposed for the purpose of reasonable loading and unloading of earthwork and the shortest path in land leveling operation. Based on the three dimensional terrain model of farmland, the improved ant colony algorithm was used for three dimensional path planning. A new path search node was established based on the decision direction of earthwork transportation in leveling operation. The pheromone updating rules and heuristic functions of land leveling were set up by comparing the earthwork carried by the leveling shovel and the excavation and filling volume required by grid calculation, and then the optimal three dimensional path for earthwork transportation was obtained. The path was smoothed and optimized according to the steering constraints of land leveler, which was based on the kinematical model of the land leveler. And the effect evaluation standard of three dimensional path planning was established. The simulation results showed that compared with the original ant colony algorithm, the path planning effect of this method was improved by more than 33.3%, which could better guide the land leveler to realize the local leveling task. Moreover, this method shortened the path generation time and path length, making the path smoother, and was more suitable for automatic navigation of farmland leveling.