New robot mimics insect optic-neuron pathway

Equipped with brains the size of a pinhead, insects perform fantastic navigational feats. They avoid obstacles and move through small openings. How do they do this with their limited brain power? Understanding the inner workings of an insect’s brain can help us in our search for energy-efficient computing; physicist Elisabetta Chicca from the University of Groningen demonstrates this with her most recent result: a robot that acts like an insect.

It’s not easy to use the images that pass through your eyes to decide what your feet or wings should do. A key aspect here is the apparent movement of things when you move. “Like when you’re on a train,” Chicca explains. “Nearby trees appear to move faster than distant houses. Insects use this information to infer how far away objects are. This works well when they move in a straight line, but the reality is not so simple.”

Moving around curves makes the problem too complex for insects. To keep things manageable for their limited intelligence, they adjust their behavior: they fly in a straight line, make a turn, then make another straight line. Chicca explains: “What we learn from this is: if you don’t have enough resources, you can simplify the problem with your behavior. »

In search of the neural mechanism that determines insect behavior, Ph.D. student Thorben Schoepe developed a model of its neural activity and a small robot that uses it to navigate. All this was done under Chicca’s supervision and in close collaboration with neurobiologist Martin Egelhaaf from the University of Bielefeld, who helped identify the computational principles of insects.

Schoepe’s model is based on one main principle: always move towards the area where movement is least apparent. He took his robot through a long “hallway” consisting of two walls with a random print and the robot was centered in the middle of the hall, as insects tend to do.

In other (virtual) environments, such as a space with obstacles or small openings, Schoepe’s model also showed insect-like behavior. “The model is so good,” concludes Chicca, “that once installed it will work in all kinds of environments.” That’s the beauty of this result.”

The fact that a robot can navigate in a realistic environment is not new. Rather, the model provides insight into how insects do their work and how they manage to do it so efficiently. Chicca explains: “A lot of robotics is not concerned with efficiency. We humans tend to learn new tasks as we grow, and in robotics this is reflected in the current trend of machine learning. But insects are able to fly immediately upon birth. An effective way to do this is written into their brains. »

Likewise, you could make computers more efficient. Chicca shows off a chip that her research group previously developed: a strip whose surface area is smaller than a key on your keyboard. In the future, she also hopes to integrate this specific insect behavior into a chip. She comments: “Instead of using a general-purpose computer with all its possibilities, you can build specific hardware, a small chip that does the job, keeping things much smaller and energy efficient.”

The results are published in the journal Natural communications.