Learning
Resources

A Short Introduction to Robotic Arms

As we watch robotic arms perform their complicated tasks, we often unconsciously develop a particular feeling for them, a kind of compassion for their hard work and dedication. Do we ever show this kind of compassion or empathy for other industrial machines? Our relationship with robotic arms differs from that with other high-precision industrial machines. While all types of industrial machinery are designed to perform precise tasks with accuracy, efficiency and repeatability, robotic arms possess unique characteristics that evoke distinct perceptions and interactions from humans. The difference lies in the fact that they often embody anthropomorphic qualities, resembling the structure and movements of the human arm and hand. This evokes a sense of familiarity, making us relate to them differently.
It was in 1938 that Willard Pollard patented a position controlling apparatus, a precursor to modern robotic arms. This apparatus comprises a spray gun for spraying a liquid coating onto an automobile body or the like. Although Pollard never built this device, his concept of an automated arm capable of performing precise tasks inspired subsequent innovations. Almost at the same time, the American writer Isaac Asimov introduces the word robotics in his novel Runaround, part of the series I, Robot in which he proposes three rules concerning the behaviour that robots should adopt in interaction with humans. These rules became the three Laws of Robotics (1942). Almost ten years later, George Devol files a patent for a Programmable Article Transfer (1954) which represents the basis of what will become one of the first industrial robots in industry, the Unimate. Devol's invention was revolutionary because it was the first programmable robotic arm, capable of being instructed to perform a sequence of movements autonomously. Engelberger, often referred to as the "father of robotics," played a crucial role in commercialising Devol's invention and establishing the company Unimation, which produced the Unimate. This industrial robot was firstly used by General Motors for die-casting handling and welding.
Another breakthrough came from Victor Scheinmann and was called the Stanford Arm. This arm was one of the first to use electric motors rather than hydraulics, providing greater precision and control. The Stanford Arm could move along six axes, which made it highly versatile and suitable for a wide range of tasks​. Almost at the same time Marvin Minsky, an important figure in modern science and artificial intelligence introduced the Tentacle Arm at MIT (1968). It reproduces a human arm with a hand and also offers 6 degrees of freedom. Minsky's vision of intelligent robotics was not merely about creating efficient machines but about exploring the possibilities of machines as intelligent agents capable of nuanced interactions with their environment.

Thus, the foundations were laid for the development and use of industrial robots, and this has continued increasingly since those times. These industrial robots, because of their size, weight and power, were often operated in a protected environment to avoid accidents. Most were programmed to repeat a set sequence of tasks, and consequently have no built-in intelligent system which would enable them to adapt to circumstances or make particular decisions. However, during the last two decades a new type of robotic arm has made its way. These robots are made to co-operate in the proximity of humans and are designed as collaborative robots or cobots. These robots are based on the same principles as their production-line counterparts, but they are designed to work in the presence of and in collaboration with a person. They are therefore equipped with safety systems, are less powerful and have lower payloads. Universal Robots is a pioneering manufacturer of this kind of robot, but they're not the only ones. Other major players include ABB, Fanuc and Kuka.

That is the kind of robotic arms that will be presented and used during the following chapters. Cobots represent a shift in the relation that we can have with a robotic arm as they transition from a mere productivity machine to a creative tool open to experimentation and novel applications.