Improving drone collision avoidance technology

AUTOMATION has led to an increase in the use of unmanned aerial vehicles (UAVs), commonly known as drones, in many fields, ranging from the film industry to agricultural applications and military operations.

This boom has created new challenges for automation to overcome, including the need for UAVs to fly in crowded airspaces and avoid colliding with each other.

To help address the deficiency in inter-UAV collision avoidance capabilities, Dr Lauren Meiring developed and evaluated co-operative collision avoidance algorithms for UAVs that are capable of avoiding short-term collisions with static and dynamic obstacles as well as collisions between UAVs while communicating their positions, velocities and intended flight trajectories in complex environments.

Meiring recently obtained her doctorate in Electronic Engineering at Stellenbosch University. The title of her thesis was Co-operative Collision Avoidance Strategies for Unmanned Aerial Vehicles.

“Currently, there is no commonly implemented collision avoidance system that prevents inter-UAV collisions. Some commercially available UAVs do implement collision avoidance, but only for static obstacles. When UAVs are equipped with inter-UAV collision avoidance, it is normally to achieve a specialised task and, as such, is not applicable to independent UAVs performing individual tasks,” said Meiring.

“These UAVs are assumed to be following long-term routes, such as flying between warehouses. When a collision is predicted along these routes, all UAVs co-operate to plan and execute short-term collision avoidance trajectories. The UAVs use horizontal, vertical, or three-dimensional manoeuvres to avoid collisions with one another, with static terrain and with dynamic obstacles.”

According to Meiring, current collision avoidance technologies used in commercial airspace, namely TCAS (Traffic Alert and Collision Avoidance System) and GPWS (Ground Proximity Warning System), are rules-based, non-co-operative and decoupled approaches that are not suitable for UAV collision avoidance in extremely congested airspace with complex terrain.

Meiring said her approach did not require the UAVs to be working together towards the same goal. They merely had to be in communication with each other.