When a robot extends an object to a person or, on the contrary, picks it up, people prefer the robot to act with a slight delay, and the movements themselves should be slow or moderate in speed, researchers from Disney Research found out. At the same time, both large and smaller delays reduce warm feelings towards the robot.
A significant part of robotics engineers is not engaged in the creation of robots, but the study of the interaction between humans and robots. They study how people perceive different aspects of robot behaviour, and develop methods that increase the level of confidence in machines and their attractiveness to humans.
For example, the phenomenon of the “sinister valley” is widely known. It lies in the fact that human-like robots, with small deviations from the appearance or behaviour of people, cause much greater hostility and fear than less human-like robots. By exploring such aspects of human perception, engineers will be able to create robots that can coexist with people and help them without causing negative emotions.
In their work, researchers at Disney Research, led by Günter Niemeyer, studied what the robot’s movements should be when it exchanges an object with a person. Usually, after we are given an object, we begin to reach out to him not instantly, but with a slight delay. Robots are technically capable of acting without this delay, but the researchers decided to find out whether to do so.
They used a stand that looked like a humanoid torso with a hand and a bear’s head on top (apparently, in this way, the researchers tried to slightly alienate the image of the robot from the person in order to avoid the manifestation of the “sinister valley” effect due to the human face). In fact, under the clothes of the robot hides a serial robotic manipulator KUKA. The robot could raise and lower its hand, as well as grab or release objects with the fingers. As a model item, the engineer used a ring with sensors for an external tracking system, with which the robot found out that the user had handed him a ring.
During the experiments, the robot and the volunteer (there were 18 in total) transferred the ring to each other, and after that the person evaluated the warmth of the relationship with the robot, its ability to perform its task, as well as the discomfort from interaction, under different modes of operation of the robot. The authors created nine modes, changing the speed of the robot arm (fast, moderate or slow) and the delay before the start of movement (no delay, small and large delay).
The results of the experiment showed that a small delay provides the warmest attitude to the robot, as well as the least discomfort. Regarding speed, the researchers found that people do not like fast movements of the robot arm, but they did not find significant differences between moderate and slow speeds. The authors note that the discomfort of high speed can be associated with the mass, size or appearance of the hand, so these parameters need to be investigated in future works.
Last year, other engineers found out what kind of hugs people like with a robot. It turned out that people prefer the hugs of a soft robot that lets them go immediately after they let him go. In addition, after experiments, people began to evaluate the emotional characteristics of the robot much higher.