Abstract :Recently we witnessed an increasing trend for autonomous aerial vehicles in the city’s sky to deliver goods, transport passengers, attend medical support and more. These vehicles perform high mobility for point-to-point missions, but to do so, they should cruise across the sky with minimum interference. As these trends grow, more vehicles will demand these safe routes as more potential collisions require resolution.
Here we give some insights to a preliminary novel concept of a low-altitude air transport system (LAAT) that supplies the infrastructure for the aerial vehicles to move in the urban area. Inspired by the well-researched ground transportation methods, the suggested LAAT system is based on the natural relation between density and accumulation of the vehicles in a given area – as described in the macroscopic fundamental diagram (MFD), and then using a flow control method called perimeter control to regulate the inter-regional flow from adjacent regions.
A micro-simulation of a LAAT vehicle was designed, including mission definition and collision avoidance mechanism, and then it was implemented in an aggregated simulation to show that an MFD-like relation exists in a given region of LAAT system similarly to ground traffic MFD. Then, an adaptive perimeter controller is designed and tested in several multi-regional simulations. The controller performance was measured in the meaning of network congestion avoidance in different scenarios, including different number of connected regions, different regional and inter-regional flow demand (attraction) and tested on the plant model – either original non-linear model or simplified partially-linearized model.
The simulations show that the aerial vehicles flow indeed perform a MFD relation, and the extracted MFD was used to design a perimeter controller. The simulations show that the controller successfully prevents congestion on the partially-linearized model of the multi-regional scenarios and extends the stability of the system to harsh demand in the original non-linear model of the multi-regional scenarios.
Afterwards, robustness research was performed on the designed perimeter controller to evaluate the dependency of the solutions improvement on several key parameters under expected real-life implementation difficulties such as controller-plant channel delay and control communication constraints.