城市低空物流无人机航迹规划模型研究

为提高物流无人机在城市低空环境下配送的安全性和公众接受程度，保证运输经济性，提出一种考虑运行风险、噪声水平和运输成本的城市低空物流无人机航迹规划方法。采用栅格法进行空域环境表征，建立基于风险的城市空域环境模型。结合物流配送要求，建立多目标、多约束的物流无人机航迹规划模型。采用改进A*算法进行求解：为降低航迹代价，设计估价函数预估成本；为保证飞行安全，引入安全保护区确保间隔；为提升搜索效率，采用动态步长加快搜索进程。仿真结果表明：本文模型和算法所得航迹的运行风险小、噪声水平低、运输成本低，能够实现多目标优化。分析模型参数可知，当各子目标代价权重分别为0.6、0.1和0.3时，规划航迹最优。 保证其余参数不变，增大安全间隔，则风险代价、运输成本代价总体呈增加趋势，噪声代价减少。 在本文规划环境下，参考大疆经纬200无人机参数，在安全间隔取15 m时，综合代价最小。

Track Planning Model for Logistics Unmanned Aerial Vehicle in Urban Low-altitude Airspace

To improve the delivery safety and public acceptance of logistics unmanned aerial vehicle (UAV) in urban low-altitude airspace, and ensure the transportation economy, this paper proposed a track planning method for logistics UAV in urban low-altitude and considered the operational risk, noise level and transportation cost. The airspace was characterized by the grid method, and a risk-based urban airspace model was developed. A multi-objective and multiconstraint model of logistics UAV track planning was established combined with the requirements of logistics distribution. The improved A* algorithm was used to solve the problem. The evaluation function was designed to estimate the costs. The safety protection area was introduced to ensure separation and flight safety. To improve the search efficiency, a dynamic step length method was adopted to speed up the search process. The simulation results show that the proposed model and algorithm can achieve multi-objective optimization with low operational risk, low noise level, and low transportation cost. By analyzing the model parameters, when the cost weights of each sub-target are respectively 0.6、0.1 and 0.3, the planned flight track is optimal. If the remaining parameters remain unchanged and the safety separation is improved, the risk cost and transportation cost would generally increase, and the noise cost would decrease. In the planning environment of this paper, with reference to the parameters of DJI Matrice200, the comprehensive cost is minimum when the safety separation is set at 15 meters.