Humanoid Robots

Humanoid robots are machines with a human-like body structure. Typical features are two legs, two arms with hands, and a head with cameras. The reason for this form is practical: our world is built for humans. Stairs, door handles, shelves, and drills are suited to a human body, not to wheels or gripping claws. A machine in human form can, in principle, use these things without any modifications. A humanoid robot is far removed from humans with machine parts in their bodies, i.e., cyborgs from movies: it consists entirely of metal, plastic, motors, and electronics.

Why the human form is becoming interesting right now

Walking robots have existed for decades. For a long time they were mainly research objects that barely did anything useful. What’s new is that they are now also supposed to understand what is happening around them. This is made possible by large AI models that have learned from huge amounts of image, text, and motion data. A robot can thus receive a spoken instruction and derive a suitable action from it.

Economically, the promise is huge. In many countries there is a shortage of workers in warehouses, in care, and in manufacturing. An industrial robot in a car factory is bolted down and can do exactly one task. A humanoid robot, by contrast, is supposed to do something different tomorrow than today, simply by being given a new instruction. That is why car manufacturers, chip makers, and start-ups are investing billions in this technology.

A typical mistake here is to infer market-readiness from a video. Many demonstrations are often rehearsed, sped up, or controlled remotely by a human. Between a successful demo run and a robot that works reliably for eight hours, there are still years of development.

Balance, grasping, and trained movement

A humanoid robot can be broken down into three levels. The sensors capture the environment: cameras, depth sensors, and orientation sensors that detect tilt and rotation. The controller calculates from this what needs to be done. The actuators carry it out, usually electric motors in the joints. A modern humanoid often has 30 to 50 such movable joints.

The most difficult problem is balance. A two-legged body is inherently unstable and would fall over while standing still. The controller therefore corrects the joint angles hundreds of times per second — similar to how you constantly make imperceptible adjustments when standing on one leg. If this control fails, the machine tips over immediately.

Movements today are usually no longer programmed line by line. Instead, software practices in a simulation, i.e., a physically calculated computer model of the world. There it can perform thousands of virtual trials per hour without damaging real hardware. What is learned is then transferred to the real robot. Because simulation and reality never fully match, some of the performance is often lost in the process.

From the warehouse to the auto show

In everyday life, you rarely encounter humanoid robots so far. Most likely in the news, in factory halls as test devices, or as crowd magnets at trade fairs and in shopping malls. First pilot projects are running in logistics warehouses, where robots move boxes around. These are controlled environments with flat floors and few surprises.

In business news, the same names keep coming up. Tesla is working on Optimus, the US company Figure on models for factories, Boston Dynamics on Atlas. From China come providers like Unitree, who sell comparatively affordable devices. Quoted prices range, depending on the model, from a few tens of thousands to several hundred thousand euros.

An important distinction: not every service robot is humanoid. A vacuum robot, a delivery robot on wheels, and a robotic arm solve their tasks without human form, often more cheaply and robustly. The human form is only worthwhile where many different activities occur in an unmodified environment. Whether this case occurs often enough is the industry’s actual open question.