To enhance emotional interactions between robots and users, experts are seeking to increase the number of motors and expressions on robot faces.
Liu Xiaofeng, a professor at Hohai University in Jiangsu Province, eastern China, along with his research team, is developing humanoid robots with highly expressive faces, as reported by Xinhua on August 2. The new research, published in the international journal IEEE Transactions on Robotics, aims to optimize emotional interaction technology between humans and robots.
Professor Liu Xiaofeng discusses humanoid robots with a researcher at Hohai University. (Photo: Xinhua).
Humanoid robots often struggle to convey the complex and realistic facial expressions characteristic of humans. This can hinder their ability to interact with users, Liu stated. “To tackle this challenge, we introduce a comprehensive two-stage method that equips our robots with the ability to express facial emotions richly and naturally.”
Liu explained that in the first stage, their method generates expressive facial images of the robot based on Action Units (AUs). In the next stage, they realize an emotionally rich robot with varying degrees of free facial movement, allowing the robot to express detailed emotions.
People may be more familiar with “digital humans” and “virtual editors” capable of generating numerous real-time expressions, according to Ni Rongrong, an expert at Changzhou University and co-author of the study. However, humanoid robots face certain limitations, such as size and the number of motors, making this more challenging. “For instance, the humanoid robot we previously used had only nine tiny motors beneath its face, far fewer than the muscles in a human face,” Ni noted.
As a result, the research team divided the nine motors on the humanoid robot’s face into 17 AUs to provide richer expressions and smoother transitions through coordinated movements. They plan to continue increasing the number of AUs on the face and equip the robot with the ability to express subtle emotions autonomously.
Liu believes that as the emotional interaction capabilities of humanoid robots continue to advance, robots with high emotional and intellectual indices will be widely used in nursing homes, kindergartens, special education schools, and other facilities. “Humanoid robots will not only assist or replace humans in completing certain tasks but will also bring greater emotional value,” he stated.
