In view of the booming of flight flow of urban logistics UAVs and low airspace utilization due to isolation mode of operation, safe and efficient cross-operation needs to be implemented. The crossing separation model was constructed by studying the crossing operation collision risk at the same altitude, and the core parameters such as lateral error, vertical error and longitudinal proximity rate were determined. By introducing the Event model method and constructing separation model, the failure probability of airborne CDR system was further considered. By using event tree analysis method, a comprehensive model of urban logistics UAV crossing separation was proposed and constructed. Results show that the required crossing separation is 158 m for the target safety of level 1.5×10-8 and 155 m for the target safety of level 1×10-6 when the route angle is 60 degrees. With the increase of crossing angle, the required separation generally shows an upward trend. When it approaches 180°, that is, opposite direction operation, the required separation increases sharply, which is consistent with the actual cognition.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |