Berlin researchers develop a robot that can learn to navigate through its environment guided by external stimuli
Researchers of Freie Universität Berlin, of the Bernstein Fokus Neuronal Basis of Learning, and of the Bernstein Center Berlin and have developed a robot that perceives environmental stimuli and learns to react to them. The scientists used the relatively simple nervous system of the honeybee as a model for its working principles. To this end, they installed a camera on a small robotic vehicle and connected it to a computer. The computer program replicated in a simplified way the sensorimotor network of the insect brain. The input data came from the camera that—akin to an eye—received and projected visual information. The neural network, in turn, operated the motors of the robot wheels—and could thus control its motion direction.
The outstanding feature of this artifical mini brain is its ability to learn by simple principles. “The network-controlled robot is able to link certain external stimuli with behavioral rules,” says Professor Martin Paul Nawrot, head of the research team and professor of neuroscience at Freie Universität Berlin. “Much like honeybees learn to associate certain flower colors with tasty nectar, the robot learns to approach certain colored objects and to avoid others.”
In the learning experiment, the scientists located the network-controlled robot in the center of a small arena. Red and blue objects were installed on the walls. Once the robot’s camera focused on an object with the desired color—red, for instance—, the scientists triggered a light flash. This signal activated a so-called reward sensor nerve cell in the artificial network. The simultaneous processing of red color and the reward now led to specific changes in those parts of the network, which exercised control over the robot wheels. As a consequence, when the robot “saw” another red object, it started to move toward it. Blue items, in contrast, made it move backwards. “Just within seconds, the robot accomplishes the task to find an object in the desired color and to approach it,” explains Nawrot. “Only a single learning trial is needed, similar to experimental observations in honeybees.”
The current study was carried out at Freie Universität Berlin within an interdisciplinary collaboration between the research groups “Neuroinformatics” (Institute of Biology) led by Professor Martin Paul Nawrot and “Intelligent Systems and Robotics” (Institute of Computer Science) led by Professor Raúl Rojas. The scientists are now planning to expand their neural network by supplementing more learning principles. Thus, the mini brain will become even more powerful—and the robot more autonomous.
Sensors in beehives may capture early signs of disease
To the human ear, the buzz of the honeybee can sound like one unchanging hum. Yet a group of researchers hopes that decoding tiny variations in the noise could help halt the catastrophic decline in the world’s honeybee population.
The researchers, led by a team at Nottingham Trent University in England, believe the changing sounds from a hive indicate swings in the bees’ state of health and that high-tech eavesdropping could provide beekeepers with early-warning signals. Supported by a $1.8-million grant from the European Union, the scientists aim to analyze the buzz from 20 hives kept at a village in rural southeastern France in a five-year experiment that started earlier this spring.
Team leader Martin Bencsik has previously used sensors known as accelerometers to capture a distinct change in bee sounds before the phenomenon known as swarming, which is when the queen quits the hive, taking many of the worker bees with her. The challenge this time is to identify variations in the buzz that can be linked to disease, including colony collapse disorder—a mysterious ailment that has weakened colonies around the world. The researchers’ key tool: industrial sensors designed to pick up subtle changes in vibration patterns. Embedded in the wall of the hive, miniature accelerometers will measure the vibrations in the honeycomb caused by the bees’ activity and the sounds they create. With no ears, bees are generally thought to rely on vibrations—received through their legs—to communicate with one another.