HuggieBot 3.0 – Robot Uses Science to Deliver the Perfect Hug

HuggieBot 3.0 is the third iteration of a robot designed by a team at the Max Planck Institute for Intelligent Systems to deliver the perfect hug.

Hugging probably isn’t the first thing that comes to mind when thinking about things that robots could help humankind with, but a team of scientists at the Max Planck Institute for Intelligent Systems disagrees. Alexis E. Block and her colleagues have been involved in the HuggieBot project for years, trying to create a robot that could deliver human-like hugs and thus replace actual people in various scenarios like providing comfort to the lonely, or replacing someone who just can’t deliver a hug in person for some reason. Their third iteration, the HuggieBot 3.0, is apparently quite the hugger…

Photo: Institute for Intelligent Systems/Project HuggieBot

The creators of HuggieBot 3.0 claim that it is “the first fully autonomous human-sized hugging robot that recognizes and responds to the user’s intra-hug gestures”. It features a custom sensing system called ‘HuggieChest’ which incorporates two inflated chambers of polyvinyl chloride to imitate a soft chest. But there’s a lot more than a soft chest to the HuggieBot 3.0.

The advanced robot delivers hugs using a pair of Kinova JACO arms mounted to a custom metal frame that were selected for being anthropomorphic, quiet, and safe. As a hug takes place, a barometric pressure sensor and microphone inside the artificial chest detect human touch and begin transmitting data via an Arduino Mega microcontroller board to a Robot Operating System (ROS)-based computer located in the HuggieBot 3.0’s 3D-printed head.

The team used feedback from 512 real people over 32 trials to train a machine learning system capable of detecting and classifying a range of gestures performed during a hug and responding appropriately. The HuggieBot 3.0 can stay still, move slightly vertically, tap or pat a person’s back and squeeze with varying degrees of pressure.

Rather than maximizing user acceptance for each robot gesture, which would result in the robot only squeezing the user, our behavior algorithm balances exploration and exploitation to create a natural, spontaneous robot that provides comforting hugs,” the team behind HuggieBot 3.0 wrote in a recent study.


Alexis E. Block started working on the original HuggieBot back in 2016 while studying for a Master’s degree in robotics. The first iteration was built on six “hugging commandments”, such as the need for the robot to be soft and warm, and to autonomously enter into and end an embrace.

The HuggieBit 2.0 took the project a step further by incorporating haptic perception to deliver adaptive hugging, but the 3.0 iteration is the most advanced version yet, with five added hugging commandments designed to deliver a human-like hugging experience.


In a recent test on 16 participants who had also tried previous versions of the HuggieBot, 12 participants who hugged the robot for longer declared that they felt significantly more understood by the machine and that it was “significantly nicer to hug” than previous iterations.

The HuggieBot 3.0 isn’t perfect, and its creators point out that it isn’t quite like hugging a real person just yet, but they are already working on a fourth version that should come with improved hug positioning and techniques. They hope that one day HuggieBot will be able to replicate the sensation of human hugging to perfection.

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