Some people think they're just the protagonists of some of the most famous sci-fi genre films, in reality humanoid robots are somehow already living among us. And, switched on and functioning, they perform different kinds of actions on a daily basis, even non-trivial ones. As the name suggests, a humanoid robot is a machine with its own artificial intelligence that shows similar appearances to humans. In some cases, even very similar, so as to get to talk about androids. A branch of robotics, the humanoid one, which has the ambitious task of reproducing as closely as possible the physical and cognitive activities of the person, even going to improve them where possible.
In fact, we are faced with machines shaped in our image and likeness belonging to a "population" increasingly numerous, with all the technical, ethical and moral implications of the case. And that, in the final analysis, are able to carry out a wide range of activities in place of man in a more or less autonomous way. Since this is such a vast and complex field, in this guide we will try to explain as simply as possible what are the differences between the various types of robots, exploring the "nature" and functions of anthropomorphic robot, humanoid robot and android.
From anthropomorphic robot to humanoid robot
Before focusing on the real protagonist of this our guide - yes, precisely the fascinating and controversial humanoid robot - it is good to clarify what are the variables that come into play to differentiate the different expressions of robotics. Starting, not surprisingly, with anthropomorphic robots. These are machines that have the ability to imitate some of the abilities of humans, such as the ability to move or the perception of the spaces that make up and delimit the world around us.
Nowadays, the largest set of anthropomorphic robotics includes both industrial robotics and humanoid robotics: in the first scenario we are referring to all those robots that imitate human capabilities - think for example of mechanical arms that reproduce the movement and skills of human arms and hands -, while in the second case to those that actually have human features, and are composed of head, torso, arms and legs.
And if it is true that humanoid robots have evolved at an impressive rate only in a handful of years, at the moment there is a tendency to identify anthropomorphic robotics with industrial robotics, in particular with robotic arms - also known as robotic arms -, which are used within companies in place of or alongside humans throughout the cycle of the production chain. In the name of an industrial automation now at levels not even imaginable until a few decades ago.
In the face of such an incisive progress, today in the large family of industrial robotics, collaborative robots are assuming an increasingly important role. In this specific case, we are still talking about industrial robots, but those that do not need to be programmed before being inserted into the production cycle, but in fact go to learn in the field by exploiting a series of sensors and calculation and analysis units. As a result, robotic arms are equipped with the ability to memorize all the movements and operations carried out by a human operator, then subsequently replicated to perfection and with significantly reduced times.
In any case, these "creatures" resulting from research present evident differences with the humanoid robot, which can be defined as an autonomous machine with human features capable of interacting with the surrounding environment. Very often the term is used as a synonym of android: in practice, however, the tendency is to distinguish them using the term humanoid robot for those automata that are inspired by humans, and the term android for those robots that have human features and are simultaneously equipped with sophisticated artificial intelligence systems.
As you can guess, then, an android is to all intents and purposes a humanoid robot equipped with its own AI, which can be more or less advanced. An automaton, in short, in turn different from those futuristic cyborgs that instead propose an "augmented" human being, that is, a biological body improved with various artificial grafts. In the final analysis, it is important to clarify that the term android is used both in the masculine and feminine, although the term gynoid has been coined to describe a humanoid robot with female features.
In all cases, then, this type of machines are made to perceive through sensors the outside world, and made virtually "alive" with artificial intelligence. They also react to external stimuli by means of actuators, i.e. the motor muscles that allow them to move just like we do in our daily lives.
Humanoid robots: the most famous cases
Humanoid robots are now heard of more and more often. Many are the "famous" cases that have colored the chronicles, not only of an exquisitely scientific and strictly technical nature. Among these, it is impossible not to mention Asimo, which appeared for the first time in 2000 as the eleventh evolution of previous prototypes developed by Honda - which only later decided to abandon the project. The dimensions of the most evolved model, produced in 2011, are 130 centimetres in height and 48 kilos in weight, and it is able to walk effortlessly at almost 3 kilometres per hour, even running at almost three times the speed.
Impressive also the dynamic performance, considering that Asimo can go up and down stairs, jump on one leg, move the upper limbs and the five fingers of the hands. On the cognitive level, it can also recognize the surrounding environment, keep under control and follow moving objects, and distinguish human beings, whose body posture and voice intonation it is able to interpret.
Next to the machine dedicated to the incomparable Isaac Asimov - science fiction writer and father of the term robotics - we find Pepper, which can be defined as a semi-humanoid. This robot, in fact, does not have legs, which have been replaced by faster wheels, and that support a total structure of one meter and thirty in height for 28 kilograms of weight. Produced by Softbank Robotics, Pepper features touch sensors at the ends of its upper limbs, sonar, laser and gyroscope in the base to move optimally in the surrounding space.
There are also two cameras on its face and four microphones, while there is a tablet on its chest as an additional interaction interface. All this for a machine that is commonly referred to as a "social robot", considering that its standard artificial intelligence includes an evolved ability to interact with humans. It is therefore no coincidence that it can be spotted in action in various public places, airports or hospitals. Next, we have the humanoid robot Reem C, Spanish-made in the industrious forges of Pal Laboratories. At the moment it has reached its fourth evolution, equipped with an improved locomotion system - passing from a "simple" wheeled cart to real humanoid limbs.
It certainly does not stand out for the speed of movement - fixed at 1.5 kilometers by now -, but its structure of one meter and 65 by 80 kg allows it to lift and carry up to 10 kg of weight. Among the most interesting projects, we should also mention RoboThespian, developed and distributed by the British Engineered Arts. In particular, it is a robot that knows how to act and hold the stage thanks to its strong irony, moreover its facial expressiveness is unique in the world of artificial intelligence.
To continue our overview, a clear example of Italian humanoid robots: iCub. Result of the work of the Italian Institute of Technology (IIT) based in Genoa, is a small robot - we speak of 104 centimeters in height - which replicates the features of a five year old child. With skin that is particularly sensitive because it is covered with numerous tactile sensors, iCub is capable of crawling, walking, sitting, gently manipulating objects and even learning to shoot a bow.
Between robot receptionists, journalists and presenters - just to name a few -, the most representative humanoid robot of all, even today, remains Sophia. A humanoid robot with female features - whose features are inspired by the face of the iconic Audrey Hepburn -, she was activated in 2015 by researchers at Hanson Robotics. Sophia can talk to people and have her own sense of humor, reproduce as many as 62 facial expressions and express emotions. A heated discussion arose around her when, in October 2017, she was presented to the UN and granted citizenship by Saudi Arabia, thus becoming the first robot in history to be a citizen of a state.
With a status other than that of a mere object. She has even successfully participated in several interviews: hearing her answer, interact and laugh makes you imagine an evolved world - and different from the one we live in today - where humans and humanoid robots can live together in harmony.