**3. COBOTs**

*Collaborative and Humanoid Robots*

**Figure 1.**

tive robotics.

*Four industrial revolutions.*

logical advances of the time [3].

**2. Cyber-physical systems**

other, through networks and software.

productive, sustainable and efficient factories [4].

electronics and computer science to make automated production possible. Finally, industry 4.0 emerges as a new industrial revolution incorporating the new techno-

In **Figure 1**, it is observed how the 4th industrial revolution, has a presence with robotics, intelligent technology and interconnectivity, thus giving way to collabora-

Cyber-physical Systems (SCF) incorporate and coordinate physical processes with computational elements, communication networks and remote storage of information, both interact at different scales of space and time, with different operation processes and configuration and reconfiguration resources. In addition, SCF works through "systems of systems" that interact and communicate with each

The key functions of Cyber-Physical Systems in the industry are the development of sensors and actuators to perform control actions, monitoring, generation of new knowledge, self-learning and reconfiguration based on the condition of the process. The mobile internet and the internet of things (IoT) have allowed to extend the adaptability, capacity, resilience, scalability, usability, and security of current industrialsystems. For example, wind-solar energy systems are an application of Cyber-Physical systems in industry, these wind and solar farms have their physical share while the data is obtained through monitoring sensors. The data is transferred through communication networks and processed by software in operation centers to monitor and control the physical environment, and thus obtain the most benefit from renewable sources. Also, CFS have been applied in different fields such as in the manufacture of intelligent robots, to perform human welfare services, in medical or healthcare equipment, vehicular and transport systems, surveillance systems, smart cities and video games. The SCF contributed significantly to the industrial revolution, because in the former there were no intelligent factories where components, people and production systems communicated with each other through a network and their production was autonomous. In today's industry, CFS allow the monitoring of the condition of machines or processes in real time, the detection of anomalies, the predictions of failures, the cloud as a service increasing the realization of more

**4**

With the rise of the industry due to the introduction of cyber-physical systems (SCF) and the Internet of Things (IoT) within manufacturing and automation systems. SCF represent self-controlled physical processes, with strict network capabilities and efficient interfaces for human interaction. The interactive dimension of SCF reaches its maximum when defined in terms of natural human-machine interfaces (NHMI), i.e. those that reduce the technological barriers required for interaction [5].

A collaborative robot or Cobot is defined according to ISO/TC 299 as a robot designed to interact directly with humans in a defined collaborative space. Cobots are systems or robots of an industrial nature, designed to work in robot-human environments, that is to say that it is in contact with human operators, which allows the operator's work to be complemented with the characteristics of the machine. The automotive industry, surgery, training devices and rehabilitation are some of the applications in which Cobots have been used.

The industry is currently looking to take advantage of mass customization, a task that industrial robots pre-programmed for large-scale production are not focused on, so Cobots aim to address the changes that occur in large-scale customization processes. Companies are using them because they can work alongside humans on the same assembly lines using small spaces, the necessary security measures are much less than in simple robots, they are very flexible to work on short consignments without having to invest much time in programming them and they are ideal to replace operators in repetitive or poorly ergonomic tasks.

The digitization and intelligence of the manufacturing process is the need of today's industry. Rapid advances in manufacturing technologies and applications in industries help increase productivity. Industry 4.0 as a new level of organization and control over the entire value chain of the product life cycle; it is geared towards the requirements of increasingly individualized customers. Industry 4.0 is still a hypothetical concept, but with real development that includes the Internet of Things, industrial Internet, smart manufacturing, and cloud-based manufacturing. Industry 4.0 refers to the strict integration of the human being in the manufacturing process to have a continuous improvement and focus on value-added activities and avoid waste [6].

The collaborative robotics of industrial automation has adapted to the context of rapid industrial development. The collaboration of humans and robots in close proximity in a single workspace is a novel concept of Industry 4.0. Research topics in the field of industrial robotics include safety in human-machine interaction systems, due to the close collaboration between humans and robots many of the problems of industrial robotics are associated not only with technical issues, but also with social aspects. They also include the optimization and automation of production through the introduction of robotic solutions, with which it is expected that in the future Cobots will become the basis of a large commercial development [7].

Robots are tough, fast and very accurate machines that can complete their tasks faster, with better quality and for a lower price than humans. However, some operations must be adapted to real events, but robots are not able to think, execute commands and performpre-learnedmovements, being limited by their programming. Manipulation robots are usually designed to have six or seven degrees of freedom (axes of motion), while the upper extremity of the human body has around thirty. This results in another precise manipulation limitation with a wide range of motion.

With mass custom production becoming mainstream, agile manufacturing strategies have been adopted by small and medium-sized industries (SMEs), driving the use of collaborative robots in today's factories. The main challenges in the adoption of Cobots in the industry are the lack of a highly skilled workforce to program the robot to perform complex tasks and the integration of robotic systems to other smart devices in the factory. In addition, teaching and simulation by nonrobotics experts of many collaborative robot systems is a great challenge, because these systems are designed to be programmed by experts and not by ordinary workers [8].

The main goal ofhuman-robotcollaboration (HRC) is to create an environment for safe collaboration between humans and robots. There is an area between manual manufacturing and fully automated production where a human worker comes into contact with the machine. This area has many limitations due to security restrictions. The machine can be in automatic operation only if the operational staff is outside their workspace. Collaborative robotics establishes new opportunities in cooperation between humans and machines, where staff share the workspace with the robot helping with non-ergonomic, repetitive, uncomfortable, or even dangerous operations. The robot monitors its movements by using advanced sensors so as not to limit, but mainly not to endanger the worker [9].
