  Many animals meander in environments and avoid collisions. How the underlying
neuronal machinery can yield robust behaviour in a variety of environments
remains unclear. In the fly brain, motion-sensitive neurons indicate the
presence of nearby objects and directional cues are integrated within an area
known as the central complex. Such neuronal machinery, in contrast with the
traditional stream-based approach to signal processing, uses an event-based
approach, with events occurring when changes are sensed by the animal. Contrary
to von Neumann computing architectures, event-based neuromorphic hardware is
designed to process information in an asynchronous and distributed manner.
Inspired by the fly brain, we model, for the first time, a neuromorphic
closed-loop system mimicking essential behaviours observed in flying insects,
such as meandering in clutter and gap crossing, which are highly relevant for
autonomous vehicles. We implemented our system both in software and on
neuromorphic hardware. While moving through an environment, our agent perceives
changes in its surroundings and uses this information for collision avoidance.
The agent's manoeuvres result from a closed action-perception loop implementing
probabilistic decision-making processes. This loop-closure is thought to have
driven the development of neural circuitry in biological agents since the
Cambrian explosion. In the fundamental quest to understand neural computation
in artificial agents, we come closer to understanding and modelling biological
intelligence by closing the loop also in neuromorphic systems. As a closed-loop
system, our system deepens our understanding of processing in neural networks
and computations in biological and artificial systems. With these
investigations, we aim to set the foundations for neuromorphic intelligence in
the future, moving towards leveraging the full potential of neuromorphic
systems.
