# The Development of an Advanced Air Mobility Flight Testing and Simulation Infrastructure
## 3 Development of the Platforms
### The Co-Simulation Environment  
AAM operations rely on high-level coordination and multiple services with different levels of autonomy for the safe and efficient integration of new platforms into the existing airspace system. Thus, a co-simulation environment is built to integrate and intercommunicate with all of the real and simulated elements of the demonstration. The co-simulation platform consists of three main parts: pre-flight services, a flight plan compiler, and in-flight services. Pre-flight services ensure that a new flight plan can be created easily and that the planned route is away from a geofence or a no-fly zone and has enough separation away from other airspace users by deconficting at the strategic phase and generating flight routes based on risk analysis, dynamic capacity management, and mission priority. A flight plan compiler plays a bridge role to connect pre-flight services and in-flight services. In-flight services track vehicles to ensure they follow their assigned flight routes and update the relevant operators immediately in case of a non-conformance, contingency, or emergency situation, which also may require a tactical deconfiction during the flight. Figure 3 represents the framework of the co-simulation environment. To develop such a platform, the ANRA Technologies' SmartSkies interface and the BlueSky simulator, which is used to develop the co-simulation environment, are integrated. The BlueSky simulator, which is an open air traffic simulator [50], is used to test the autonomous U-space services developed. When an operator intends to conduct a flight, it first goes through the pre-flight services. The operation plan optimization service, which is integrated with the risk analysis assistance service, can assist in proposing a route that balances costs related to the safety and efficiency of the operation by also using the information provided by the SDSP. However, demand must also meet the capacity constraints, which is provided by the dynamic capacity management service. To achieve this, the flight plan is divided into waypoints that form a four-dimensional trajectory consisting of latitude, longitude, altitude, and time. The  
Figure 3: Co-simulation environment framework. generated trajectory is then used to map the predicted traffic demand against the airspace capacity. The resulting trajectory is set as a flight plan and is presented in a specific format that includes the operator's identity, performance volume, and waypoint information for the full trajectory. This flight plan is then evaluated by the strategic conflict resolution service, which checks if it intersects with any other accepted operations. If any conflict is observed, the flight plan is rejected, and the operator is notified. The operator is then required to revise the previous planning and propose a new flight plan that avoids the conflict. This process involves identifying an alternative route that ensures the safety of the operation and satisfies the demand-capacity balancing requirement. The revised flight plan is then again evaluated by the strategic conflict resolution service to ensure that it no longer intersects with any other active operation. This process may be repeated until a satisfactory flight plan is approved and confirmed. Once flight plans are approved, the flight plan compiler steps in for flight plan processing internally, before using in-flight services. The integrated in-flight services are hosted in BlueSky simulator, which requires the stored flight plans to be converted into a useful datasets. This is achieved by using a compiler, which provides relevant simulation data as an output and connects the pre-flight and in-flight stages. There are several steps for the flight compiler module to work. First, the database for operations is parsed, and waypoints are extracted for each flight plan that will be used in conformance monitoring. The compiler then initializes the operator's position and assigns the information regarding the operation's schedule within the simulator.