How many steps does it take to peel a banana? Pick up the banana, squeeze the peel with one hand and peel it. Some people may struggle with whether to start with the head or the tail, but peeling the banana without damaging it is an easy and timeless thing to do.
▲ Image courtesy of Gettys Images
Peeling bananas is certainly not a difficult task for people (and it seems to be the same for some orangutans and monkeys). But for robots, not necessarily.
▲Image from: Daily Mail
A team of researchers at the University of Tokyo (researchers including Heecheol Kim, Yoshiyuki Ohmura, Yasuo Kuniyoshi) have developed a robot that can successfully peel bananas without destroying their pulp. However, its current success rate is only about 57%.
▲ Image from: YouTube
Peeling bananas, which seems to us effortlessly, is actually a delicate process. Every time you peel, the banana in your hand will vary in shape, size, ripeness, and overall condition, but the brain reacts quickly and makes decisions each time it peels.
For robots, this process of reacting and deciding requires a long period of learning.
▲ Image from: YouTube
The two-arm robot developed by the research team at the University of Tokyo has two UR5 (general robot) manipulators and two controllers with the same kinematic parameters as the UR5, and a ZED mini stereo camera is installed on the gimbal, and the camera is fixed in a position where bananas can be observed.
When a human operator controls the robot, the image in the stereoscopic camera is seen through a head-mounted display (HMD). An eye tracker is mounted on the display for real-time measurement of the operator's gaze position.
▲ Image from: arXiv
To train the robot to peel bananas, the researchers used a large number of human demonstrations of the banana peeling process, using this data to train through "deep imitation learning" . During the robot's 13-hour training session, the process of peeling bananas was broken down into 9 steps:
Grab the banana; lift the banana that was caught; reach out your right hand to grasp the tip of the banana; peel off the tip of the banana; the right hand near the right peel; hold the peel in the right hand and peel it; rotate the banana to reposition it so that the right hand can touch the left peel; the right hand is close to the left peel; the right hand holds the left peel and peels it off.
▲ Image from: arXiv
After a long period of deep learning, in successful tests, the robot was able to peel a banana in about 3 minutes. Of course, there are also times of failure, bananas may slide down from the hands of the machine, and may squeeze the pulp when peeling... So the current chance of successful skinning is only 57%.
▲ Image from: arXiv
These data show that there is still a lot of room for improvement in the robot from having this skill. So the research team's goal now is to improve the robot's skills, increase its speed and reliability, and also hope that it can play a role in other delicate tasks besides banana peeling, thus helping to solve the problem of labor shortages in certain industries.
Chippy of Chipotle Restaurant, picture from: cnBeta
For example, it can be a "machine worker" in a labor-starved restaurant industry. In fact, there are already restaurants using robots in the kitchen for assistance, such as Chippy at Chipotle Restaurant and Flippy in White Castle. If this robot that can peel bananas can perform more delicate operations, it will surely bring more possibilities.