iRonCub3: World’s 1st jet-powered humanoid could transform disaster relief

Roboticists at the Italian Institute of Technology (IIT) have provided a sneak peek into the experimental area and preliminary validations of the world’s first jet-powered humanoid robot.

Named iRonCub, the humanoid is equipped with four compact jet engines, which gives it the ability to fly and carry out advanced missions.

The researchers think that the ability to fly may benefit these robots in specific applications, including disaster relief, as it is currently an unknown area of research for humanoids.

With experiments initiated in 2021 , the team at IIT has faced challenges during testing, as they’ve struggled to prevent their robot from catching fire or even exploding due to engine exhaust.

Next-gen robotics

The team has developed prototypes of the iRonCub, built on the iCub v2.5 and v3.0 platforms. iCub is a research-grade humanoid robot , created by IIT, designed to help develop and test embodied AI algorithms.

The iCub has 53 degrees of freedom, nine in each hand and most in the upper torso. It is equipped with a full-body skin, force/torque sensors, cameras, microphones, gyros, accelerometers, and encoders in each joint.

Moving to iRonCub, both versions feature four jet engines —two mounted on the arms and two on a jetpack attached to the robot’s back. Current experiments are focused on the iRonCub version 3.

Significant modifications were made to the iCub’s hardware design to accommodate the external engines, including the creation of a new titanium spine and the addition of heat-resistant covers for protection.

iRonCub3, equipped with jet engines, weighs approximately 154 pounds (70 kilograms). The turbines generate a maximum thrust of over 1000N, and the exhaust temperature can exceed 600 degrees Celsius.

The team is currently testing iRonCub3 in a newly developed flight and control area, marking significant progress compared to the work done on iRonCub2. iRonCub3 introduces several advancements over its predecessor.

Built on the iCub3 platform, this version has removed tendons and integrated force-torque sensors into the jetpacks. Additionally, new electronics have been designed, and the control systems and planners are now of a new generation, operating at higher frequencies.

According to researchers, these improvements collectively enhance the robot’s capabilities and performance.

Humanoid flight control

A key challenge in aerial humanoid robotics is planning trajectories for both flight and walking, including the transitions between them.

A momentum-based trajectory planning algorithm was developed in Python using a direct multiple-shooting approach to tackle this. This planner has been validated through simulation and will soon be tested on the actual robot.

For flight control, algorithms were designed to manage the robot’s attitude and position, employing constrained Quadratic Programming optimization. According to researchers, the framework is adaptable to varying numbers of jet turbines and ensures compliance with physical constraints.

The team claims the research presents complexities far beyond traditional humanoid robotics challenges.

Thermodynamics plays a crucial role, with turbine exhaust gases reaching around 800 degrees Celsius and nearly the speed of sound. Aerodynamics of multi-body systems requires neural networks with physics-informed components for real-time evaluation.

Controller settings must integrate high- and low-bandwidth actuators, including joints and turbines. Planners are tasked with generating trajectories for both motor dynamics and turbines.

Researchers claim that experimental validation is critical and hazardous, leaving minimal room for improvisation.