The researchers directed the robot head to twist and turn its face in all directions while analysing its own facial expressions using a video camera and software called Computer Expression Recognition Toolbox (CERT), developed at UCSD. This process, which took place on an Intel-based Mac Mini, essentially taught the bot the correlation between facial expressions and the muscle movements required to make them. It then could build on that know-how to form its own expressions.
For example, the robot learned eyebrow narrowing, which requires the inner eyebrows to move together and the upper eyelids to close a bit to narrow the eye aperture.
"As far as we know, no other research group has used machine learning to teach a robot to make realistic facial expressions," said Tingfan Wu, a computer science PhD student from UCSD's Jacobs School of Engineering and one of the researchers on the project.
