Cats and robots are a winning combination, as evidenced by all those videos of kitties riding on Roombas. And now we have Cat Royale, a "multispecies" live installation in which three cats regularly "played" with a robot over 12 days, carefully monitored by human operators. Created by computer scientists from the University of Nottingham in collaboration with artists from a group called Blast Theory, the installation debuted at the World Science Festival in Brisbane, Australia, last year and is now a touring exhibit. The accompanying YouTube video series recently won a Webby Award, and a paper outlining the insights gleaned from the experience was similarly voted best paper at the recent Computer-Human Conference (CHI’24).
"At first glance, the project is about designing a robot to enrich the lives of a family of cats by playing with them," said co-author Steve Benford of the University of Nottingham, who led the research. "Under the surface, however, it explores the question of what it takes to trust a robot to look after our loved ones and potentially ourselves." While cats might love Roombas, not all animal encounters with robots are positive: Guide dogs for the visually impaired can get confused by delivery robots, for example, while the rise of lawn mowing robots can have a negative impact on hedgehogs, per Benford et al.
Blast Theory and the scientists first held a series of exploratory workshops to ensure the installation and robotic design would take into account the welfare of the cats. "Creating a multispecies system—where cats, robots, and humans are all accounted for—takes more than just designing the robot," said co-author Eike Schneiders of Nottingham's Mixed Reality Lab about the primary takeaway from the project. "We had to ensure animal well-being at all times, while simultaneously ensuring that the interactive installation engaged the (human) audiences around the world. This involved consideration of many elements, including the design of the enclosure, the robot, and its underlying systems, the various roles of the humans-in-the-loop, and, of course, the selection of the cats.”
Based on those discussions, the team set about building the installation: a bespoke enclosure that would be inhabited by three cats for six hours a day over 12 days. The lucky cats were named Ghostbuster, Clover, and Pumpkin—a parent and two offspring to ensure the cats were familiar with each other and comfortable sharing the enclosure. The enclosure was tricked out to essentially be a "utopia for cats," per the authors, with perches, walkways, dens, a scratching post, a water fountain, several feeding stations, a ball run, and litter boxes tucked away in secluded corners.
As for the robot, the team chose the Kino Gen3 lite robot arm, and the associated software was trained on over 7,000 videos of cats. A decision engine gave the robot autonomy and proposed activities for specific cats. Then a human operator used an interface control system to instruct the robot to execute the movements. The robotic arm's two-finger gripper was augmented with custom 3D-printed attachments so that the robot could manipulate various cat toys and accessories.
Each cat/robot interaction was evaluated for a "happiness score" based on the cat's level of engagement, body language, and so forth. Eight cameras monitored the cat and robot activities, and that footage was subsequently remixed and edited into daily YouTube highlight videos and, eventually, an eight-hour film.
A typical interaction looked something like this: On the ninth day, the decision engine directed the robot to engage with Ghostbuster, offering a "helicopter prey game" (a three-winged propeller toy with feathers at the end of a string). The robot removed the toy from the rack and began rotating it toward the center of the room while all three cats watched intensely. Pumpkin pounced first and was soon joined by Ghostbuster (the intended target), while Clover watched them play from an elevated platform. Pumpkin soon lost interest, but Ghostbuster continued to bat at the toy for several minutes. When Ghostbuster also lost interest, the robot returned the toy to the rack.
Overall, the experimental installation proved to be a success, although the authors cautioned that the size, cost, and need for humans in supporting roles means such installations are unlikely to end up in the average home. The cats stayed in the enclosure for the full 12 days without being injured or becoming so stressed that they had to be removed. The cats voluntarily chose to play with the robot for several minutes at a time when games were offered, and their body language indicated they enjoyed it—based on assessments by both an animal welfare officer and the cats' owner. And humans seemed to enjoy watching the cats play during the Brisbane installation.
There were a few wrinkles that demonstrated the importance of keeping human actors in the loop to intervene when necessary. For instance, the robot was instructed to offer a simple game with the feather boa targeted at Pumpkin, who was particularly fond of that toy. This involved the robot moving the boa counter-clockwise toward the center of the room by rotating on its base. The boa passed the ball run system and collided with one of the pipes. The human operator activated the kill switch since either the boa could break or the robot arm could break the tubes, possibly injuring the cat. The team shortened the feather boa string for future sessions to resolve the issue.
And as any cat owner will tell you, cats can learn new tricks and complicate matters in unpredictable ways. Notably, 10 days into the experiment, Clover figured out that she could physically overpower the robot's joints by pulling from a particular angle. When the robot tried to take away her favorite orange bird toy before she was ready to relinquish it, Clover pulled on the joint and unlocked it so that the human operator lost control. Clover then took the orange bird toy away from the robot and dragged it away. The string connecting the toy and the stick the robot was holding then got stuck in the water fountain, tipping the fountain over.
While the incident required human intervention to relock the joint and clean up the tipped water fountain, the authors noted that it was ultimately a good experience for Clover, whose ingenuity was rewarded by acquiring her favorite toy. "Unlike many digital interactions, the physical embodiment of the robot allowed the cats to 'disassemble' it by taking the toys from it," they wrote. "This allowed the interaction to fuel the cat's biological drive stimulated by the robot (i.e. hunting), allowing them to grab, manipulate, and drag objects (i.e., prey), this positively impacting Clover's welfare."
Proceedings of the CHI Conference on Human Factors in Computing Systems, 2024. DOI: 10.1145/3613904.3642115 (About DOIs).
