Analysis of key technologies for UAV conflict-free four-dimensional trajectory planning in controlled airspace*

At present, with the development of UAV technology, its flight capability and frequency of use continue to increase, making the integration of UAV operation into manned airspace has become an inevitable trend. This paper reviews the research status of conflict-free four-dimensional trajectory planning of manned and unmanned aerial vehicles in controlled airspace. In view of the urgent need for the application of refined air traffic control in the mixed operation environment of manned aircraft and unmanned aerial vehicles, and combining with the concept of global operation of the development frontier of air traffic control technology based on four-dimensional trajectory operation, this paper focus on the analysis of the key technical issues of conflict-free four-dimensional trajectory planning in the mixed operation of manned and unmanned aerial vehicles in controlled airspace. Conflict-free 4D trajectory planning for the mixed operation of manned-aircraft/UAV in the controlled area requires the research work on calculation of the minimum safe interval for the mixed operation of manned-aircraft/UAV, the real-time prediction of 4D trajectory of UAV , and the conflict-free 4D trajectory based on 4D digital airspace grid. etc.