Scientists from the Department of Cybernetics at the Faculty of Electrical Engineering of the Czech Technical University in collaboration with colleagues from the University of Colorado Boulder and the Istituto Italiano di Tecnologia in Genoa, who are researching the interaction between robots and humans, conducted an experiment with the board game Bubbles. A humanoid robot, iCub, and a human sit across from each other at a table and play a game with three dice and six face-up cards. The dice are rolled and the fastest person to point to the correct card wins: the colour of the highest number on the dice must match the colour of the largest bubble on the cards.
The goal was to demonstrate not only the robot's cognitive abilities, but more importantly the progress scientists have made in enabling robots to safely navigate in human-populated environments. A major contributor to this is a new reactive motion controller controlling the upper half of the humanoid. Thanks to the developed algorithm, the iCub robot is capable of smooth movement and empathetic behaviour,
and humans can feel completely safe around it.
This is also evident in the experiment in the video, where the human figure consciously prevents the robot from moving, pushes its hands away, and the robot obediently submits to its manipulation. Without these human interventions, the robot would clearly have the upper hand in the game: the humanoid, equipped with a camera, two thousand tactile receptors and a proximity sensor identifying nearby objects, analyses everything unerringly within milliseconds and the movement of its joints is immediate. A human wouldn't stand a chance in a game aimed at children from school age upwards, which requires players
to concentrate and react quickly.
The reactive motion controller, which the researchers called Harmonious, gives the robot the ability
to move very naturally and respond appropriately to environmental stimuli. "These are characteristics that have so far been attributed to organisms rather than machines. In robotics, the emphasis has so far been on planning the robot's movement, but this can only be applied in an unchanging and predictable environment, such as we are able to create in a manufacturing plant. However, if we deploy a robot in
an unstructured dynamic environment, in which we normally move around, this approach fails and it is necessary that the robot is able to behave like a human, i.e. adapt to obstacles and change the trajectory of movement according to the current situation," explains the fundamental change in the approach to humanoid interactions doc. Matěj Hoffmann, head of the humanoid robotics group at the Faculty of Electrical Engineering of CTU.
An empathetic robot inspired by nature will be able to engage with real-world environments
iCub is the first robot that can be said to be equipped with touch as well as hearing and sight. Its ability to sense touch is enabled by tactile sensors embedded in its electronic skin. Thanks to his senses, he creates a "protective bubble" around his body, which is controlled by 53 electric motors, allowing him to control space in a very similar way to a human. Based on his previous experience of visual and tactile sensations, the artificial intelligence guides him to the right solution when a ball is flying at him or someone is obstructing his movement.
"The iCub learns to perceive its surroundings similarly to the child it resembles in appearance. However, even a child-sized humanoid has a force in its motors that could potentially harm its surroundings, which is why we set the goal of developing the Harmonious controller to ensure that the robot learns the ability to react appropriately and safely," says Assoc. Matěj Hoffmann, who collaborated on the development of the controller with Ing. Jakub Rozlivek. The PhD student from the Department of Cybernetics at FEE CTU is listed as the lead author of a paper published in the November issue of IEEE Transactions On Robotics, one of the most prestigious scientific journals in the field of robotics.
To ensure the robot's smooth and natural movement, the researchers investigated, among other things, the kinematics of human movement, for example, in terms of what happens when we pick up objects. They then translated the analysed characteristics of human movement into an algorithm that controls
the robot's motion.
The Harmonious controller controls the upper half of the iCub robot's body, a total of 17 joints on the arms and torso, the largest number of degrees of freedom ever achieved in current robotics. However,
the algorithm is general and can be applied to a higher number of joints/motors and sensors/senses. This opens up a large space for the application of empathic robots in the real world and direct interaction with the environment. Humanoids will be able to share working and living spaces with humans, for example in parcel delivery, social services for communication, or in the home, where they can gradually take over selected tasks such as cleaning, elderly care or social contact.
Other robotics tasks - natural look and walk of the robot
After mastering the natural movement of the robot's upper body, the humanoid robotics group set another goal. "We are working with Jakub Rozlivek to get iCub to master the ability to see naturally. If you analyse the way he currently observes his surroundings, for example during a card experiment, it shows that he is only looking at the cards on the table, which doesn't feel natural. Ordinarily, a person will also occasionally glance at his opponent or look around him. We want to enrich the existing algorithm so that the robot can naturally change its gaze and act more naturally than before," says Matěj Hoffmann, describing the next tasks of his research group.
As a separate topic is then the walking of the robot. In the case of iCub, the Istituto Italiano di Tecnologia in Genoa, with which the Prague group is in close contact, is working on it.
The full scientific paper is available via the link https://arxiv.org/abs/2312.02711
