As the air space becomes more complex due to the introduction of new vehicles and missions using Unmanned Aircraft Systems (UAS), new methods of ensuring air space safety are needed as the risk for mid-air collisions and potential casualties grows. Risk assessments of UAS in the air space have been performed by US DOT Volpe Center and NASA Langley Research Center. They identified hazards, estimated their probabilities and risk mitigations in case a failure occurs. Many of the risks that UAS pose to the air space and ground communities are evolving.
We propose to develop engineering models of the 3-D, time-dependent hazard trajectory volume that travels with the UAS in case of a failure. This volume is larger than a projection of the crash area on the ground as some UAS may glide for a distance while others may spin before crashing. We will focus on the key failure scenarios addressed in prior studies such that our results complement the state-of-the-art by defining the potential severity of the failure as a function of space and time. The actual severity will depend on the intersection of these hazard volumes with other UAS or vulnerable people or assets. As the UAS follows its trajectory, the hazard trajectory volume of a failure change and the risk changes accordingly.
In Phase I, we will develop engineering models of the dynamics and flow characteristics of six failure scenarios that will relate the hazard volume shape and size swept by the UAV. This model will be tied to key parameters of the vehicle, its operation, and environment. This hazard volume will move and evolve with the UAV from the instant of failure to crash.
In Phase II, we will couple our hazard volume model with probability of failure models to identify, quantify, and prioritize risks to the air space. Furthermore, our model will be tied to real-time data collected from the UAVs including their identity and locations as function of time, so the hazard volume evolves in time.
This fast-running model can be used offline in the development stage of the IASMS. This model will be used in the flight planning stage to give an idea of what density of UAS is acceptable as a function of each UAS’s capability and characteristics, as well as environmental variables such as wind velocity and weather. The Hazard Volume model can also be expanded to be used in the IASMS to give risk calculations of the airspace in real time, as a component of an advanced collision avoidance system.
The model can be incorporated into any larger system that involves the autonomous management of more than one UAS in close proximity, such as avoiding catastrophic chain reaction events, as well as identifying the risk of using UAS around vulnerable assets and personnel. This model can be used in construction work, emergency responses (e.g.: firefighting, search and rescue).