How do you define a robot

When is a robot a robot?

Categorizing humanoid robots like the ASIMO from Honda is easy: they clearly belong to the robot family. Source: Wikipedia, public domain.

It's not too long ago when robots were mere science fiction. In the meantime they have become reality and make our lives easier in many ways. They help in industry, science and medicine. Modern space travel would be inconceivable without autonomous robots. But we also come across robots more and more frequently in everyday life: for example, as toy robots or as household helpers, where they vacuum the floor or clean windows. In the future, however, robots will not only serve humans as multifunctional work machines, but will also be capable of social interaction. Even today there are a number of humanoid robots that not only interpret human facial expressions, but also master their own facial expressions.

While these humanoid robots can unequivocally be classified as robots, the distinction between machine, automaton and robot is much more difficult with other types. For example, combat drones are commonly assigned to military robots. But can a remote-controlled aircraft even be a robot? Doesn't the term robot suggest an independent control? And what about the autonomously working machines used in industry? These are mostly firmly anchored and therefore cannot move freely. But isn't the robot's freedom of movement an important characteristic? If this is not the case, can a computer even count as a robot in the end?
What a robot is and what isn't is far from clear. In the following, we would like to explain which components and capabilities a machine must have in order to be called a robot.

Origin of the word "robot"

The term robot is derived from the Slavic word robota from and means something like compulsory labor. As a word for human-like machines, it was coined by the Czech writer Karel Ĉapek (1890-1938), who used it for the first time in his drama Rossum's Universal Robots used. In the play, which premiered in 1921, a company creates artificial people to serve their inventors. Ultimately, the robots rebel against the knuckle of slavery and destroy all humanity. Due to the success of the play, the word “robot” soon found use in everyday language and initially referred to humanoid robots, i.e. machines that are similar to humans in terms of shape and physiognomy.

Karel Capek coined the term robot with his play Rossum’s Universal Robots. As the story progresses, the robots take control of humanity. Source: Wikipedia, Public Domain.

The robot stories of the Russian-American science fiction writer Isaac Asimov (1920-1992) also contributed to the establishment of the term. His literary work influenced the pop-cultural confrontation with robots and solidified the idea of ​​the robot as a human-like machine with artificial intelligence.

Autonomy and multifunctionality are fundamental to robots

While both Ĉapek and Asimov limited the term “robot” to humanoid robots, it has changed over time and now includes a variety of devices that can perform mechanical work. Thomas Christaller defines the robot more generally as “Sensorimotor machines to expand human ability to act. They consist of mechatronic components, sensors and computer-based monitoring and control functions. The complexity of a robot differs significantly from other machines in that it has a greater number of degrees of freedom and the variety and scope of its forms of behavior. " The decisive characteristics of the robot are therefore a greater scope of behavior and a higher degree of autonomy compared to a conventional machine. What does this mean in concrete terms?

The difference between automatons and robots

The predicate autonomous is made up of two Greek words: cars, which means "self" in Greek and nomos for "law". The translation of autonomous is therefore "making one's own law".
The word is also in the machine cars. Composed with maiesthai (German: strive, strive, seek) this gives the word automatoswhich can be translated as "moving itself" or "happening by itself". According to the term automaton, just like a robot, it works independently. Indeed, this is the case: when triggered by a trigger, it is able to carry out a mechanical process without human effort. Examples of this are vending machines or coffee machines.

In 1738 Jacques de Vaucanson designed the automatically moving mechanical duck. Although the forerunner of modern robots, it is 'just' an automaton. Source: Wikipedia, public domain

However, while the robot can work independently within the framework of its specifications in its environment and adapt the mechanical process, the machine only repeats the predefined work process. If this process is no longer required, the machine is useless. In contrast, a robot is programmable and can therefore be used for a number of tasks. This universality of the robot is emphasized in the guidelines of the Association of German Engineers:
“Industrial robots are universally usable automatic motion machines with several axes, the movements of which are freely programmable with regard to the sequence of movements and paths or angles (i.e. without mechanical or human intervention) and, if necessary, sensor-controlled. They can be equipped with grippers, tools or other production means and can carry out handling and / or production tasks. " (VDI guideline 2860)
Similarly, the Robotic Industries Association defines a robot:
“A robot is a programmable multi-purpose handling device for moving materials, workpieces, tools or special devices. The freely programmable sequence of movements makes it usable for a wide variety of tasks. "
But when were the technical requirements for machines of this type given?

Invention of the transistor marks the beginning of the robot era

While the idea of ​​transferring physical work from humans to machines goes back to antiquity - the ancient Greeks, for example, developed temple gates that opened by themselves - it wasn't until the middle of the 20th century that humans were able to dream of universally applicable and programmable machines fulfill. Only when, as a result of the invention of the transistor in 1947, integrated circuits became possible and thus ever more powerful and smaller computers could be built, was it possible to develop robots that independently carry out more complex work processes according to programming specifications. The first machine to which this applied was the Universal Automation (short: Unimation), a programmable manipulator that could be used in industrial production. The corresponding patent was applied for in 1954 by the American inventor George Devol. The robot was born.

So let's be clear: A robot is a programmable machine equipped with several freely movable axes that performs a wide variety of tasks and activities automatically. In contrast to remote-controlled machines, robots do not need continuous external inputs, but act autonomously within the framework of their programming specifications. Automatic machines are not robots either. Because they only master one work process and cannot be programmed. Computer robots are also not considered to be robots, since freely moving axes are another characteristic of robots. However, firmly anchored robots also deserve the designation 'robots', provided they have free axes.


  • Christaller, Thomas et al., Robotics. Perspectives for human action in future society, Berlin et al. 2001.
  • Ichbiah, Daniel, robot. History, technology, development, Munich 2005.
  • Brillowski, Klaus, Introduction to Robotics, Aachen 2004.
  • Krüger, Hardy, Robotics and Ethics, Potsdam 2009.