Urban air mobility (UAM) is emerging as a new alternative to solve the traffic problem in the metropolitan area. Industries and government agencies are preparing for the future UAM system and operation. A new ATC (Air Traffic Control) strategy or aircraft separation method that reflects flight characteristics of multicopter VTOL (Vertical Take-off and Landing) aircraft is required. Particularly, approach control around the vertiport is one of the essential issues for the safe and efficient operation of UAM, and strict safety standards are required for service in populated urban areas. In this study, the concept of holding points where multicopter aircraft can hover is introduced, and three scheduling strategies for arriving aircraft are developed and evaluated by comparing the on-time performance (OTP) with hovering time and ground time. BQA (Branch Queuing Approach), SBA (Sequence-based Approach) and, SBAM (sequence-based approach with moving circles) models are proposed and compared. BQA model prioritizes airspace safety by limiting the aircraft’s travel path; SBA model allows the aircraft to move freely within the airspace and prioritizes aircraft’s arrival sequence; and finally, SBAM adds the moving circle concept to the SBA model. For each model, OTP and loss of separation (LOS) risk of the proposed models are found and they are compared by simulations. The simulation result shows that SBA and BQA have similar punctuality performance and BQA model with no LOS risk is the most efficient approach control model for multicopter VTOL aircraft of UAM.

城市空中交通（UAM）作为解决城市交通问题的一种新的替代方案正在兴起。行业和政府机构正在为将来的UAM系统和操作做准备。需要一种新的ATC（空中交通管制）策略或飞机分离方法，以反映多直升机VTOL（垂直起降）飞机的飞行特性。特别是，垂直通道周围的进场控制是UAM安全高效运行的基本问题之一，在人口稠密的城市地区服务需要严格的安全标准。在这项研究中，引入了多旋翼飞机可以悬停的保持点的概念，并通过将准时性能（OTP）与悬停时间和地面时间进行了比较，制定并评估了三种到达飞机的调度策略。提出并比较了BQA（分支排队方法），SBA（基于序列的方法）和SBAM（基于带动圈的基于序列的方法）模型。BQA模型通过限制飞机的行进路径来优先考虑空域安全；SBA模型允许飞机在空域内自由移动并确定飞机的到达顺序。最后，SBAM将动圈概念添加到SBA模型中。对于每个模型，发现了所提出模型的OTP和分离损失（LOS）风险，并通过仿真对其进行了比较。仿真结果表明，SBA和BQA的守时性能相似，无LOS风险的BQA模型是UAM多直升机VTOL飞机最有效的进近控制模型。提出并比较了SBAM（带动圈的基于序列的方法）模型。BQA模型通过限制飞机的行进路径来优先考虑空域安全；SBA模型允许飞机在空域内自由移动并确定飞机的到达顺序。最后，SBAM将动圈概念添加到SBA模型中。对于每个模型，发现了所提出模型的OTP和分离损失（LOS）风险，并通过仿真对其进行了比较。仿真结果表明，SBA和BQA的守时性能相似，无LOS风险的BQA模型是UAM多直升机VTOL飞机最有效的进近控制模型。提出并比较了SBAM（带动圈的基于序列的方法）模型。BQA模型通过限制飞机的行进路径来优先考虑空域安全；SBA模型允许飞机在空域内自由移动并确定飞机的到达顺序。最后，SBAM将动圈概念添加到SBA模型中。对于每个模型，发现了所提出模型的OTP和分离损失（LOS）风险，并通过仿真对其进行了比较。仿真结果表明，SBA和BQA的守时性能相似，无LOS风险的BQA模型是UAM多直升机VTOL飞机最有效的进近控制模型。最后，SBAM将动圈概念添加到SBA模型中。对于每个模型，发现了所提出模型的OTP和分离损失（LOS）风险，并通过仿真对其进行了比较。仿真结果表明，SBA和BQA的守时性能相似，无LOS风险的BQA模型是UAM多直升机VTOL飞机最有效的进近控制模型。最后，SBAM将动圈概念添加到SBA模型中。对于每个模型，发现了所提出模型的OTP和分离损失（LOS）风险，并通过仿真对其进行了比较。仿真结果表明，SBA和BQA的守时性能相似，无LOS风险的BQA模型是UAM多直升机VTOL飞机最有效的进近控制模型。