Industry 4.0

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The role of cobot in Industry 4.0 
José Gaspar Domingos 
Department of Mechanical Engineering, University of Porto, Portugal 
Up202104489@up.pt 
Abstract. In today's increasingly competitive landscape, companies must 
continually adapt to modern industry trends to stay ahead and generate added 
value. Collaborative robots (cobots) have been increasingly adopted in industries 
to facilitate human–robot collaboration. This report gives us an overview of 
recent developments in Industry 4.0 in the field of Cobots and their application 
in industrial tasks, which is followed with detailed review on Cobots 
programming classified into communication, optimization and learning, its safety 
measure as well as collaborative scenarios. 
Keywords: Cobots; Collaborative robots; Industry 4.0; Human-Robt 
Collaboration; 
1 Introduction 
Digital transformation is related to Industry 4.0 particularly when the goal is to reduce 
costs, enhance quality, and promote innovation. These goals can become a challenging 
journey to achieve, and it becomes obvious that to be successful, engineers and process 
must leave the traditional path of the past [1, 2]. So, the promise of the revolution 4.0 
in industry is to enable the factory of the future, including new types of intelligent 
information systems and automation as well as more flexible collaborative robots called 
“cobots” [3]. These collaboratives robot play a very important role in the context of 
Industry 4.0 revolution, as they have the ability to interact with humans safely and 
efficiently, assisting in repetitive operations performed by humans that may have 
consequences such as repetitive strain injuries, muscle pain, decreased productivity, etc. 
As a result, they are increasingly being used in industries to help workers in a wide 
range of tasks. 
 
2 Smart manufacturing in the era of Industry 4.0 
The first steps towards the fourth industrial revolution came from Germany in 2011 [1]. 
These steps aimed to promote digitalization and innovation in manufacturing, promote 
product, value chain, business model network, and as well as to promote the country’s 
position as a leader in industrial technology. 
 
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The goal of the fourth industrial revolution initially focused on the implementation of 
specific digital technologies in manufacturing [1] to perform integrated tasks, including 
real-time collection, processing, analysis, and storage of a substantial amount of data, 
and also to respond in real time to changing demands and conditions, supply networks 
and customer needs. This full integrated collaborative system is a subset of Industry 
4.0 which can be considered as a Smart manufacturing [4]. 
 
 
 
3 Robot collaborations in industry 4.0 
Collaboratives robots, or “cobots”, were developed with the aim of working alongside 
humans in a shared workplace to perform manufacturing processes on workpieces, such 
as pick-and-place, assembly, screwdriving or inspection [5, 6]. Cobots tend to help 
human in a variety of ways, such as to perform tasks that would be dangerous for human 
or repetitive tasks that may cause repetitive strain injuries and, the most important thing 
is that they increase the quality and quantity of the production line. 
Industry 4.0 brings capabilities to cobots in the following areas: 
3.1 Collaborative scenarios of robots in Industry 4.0 
All kinds of work situations in which human operators and Cobots will cooperate 
together, such as simple tasks and collaborative tasks, are combined into a collaborative 
system [7]. 
 
According to research, definitions of collaborative robot scenarios in industry have 
varied on what constitutes human-robot “collaboration” versus “interaction” and 
“cooperation” [6]. One scenario defines the physical proximity between human and a 
robot, with cooperative robot working in closer proximity to a human than to a 
collaborative robot. The other scenario states that a human can contact a cooperative 
robot if it is stationary, while the collaborative robot can be contacted by a human even 
if it is moving [8]. In this report was taken into account the a idea coming from Zaatari, 
Marei and Usman et al. [6] which states that any robot operating without a fence 
alongside a human is a collaborative robot. 
The types of collaborative scenarios are listed here [7]: 
• Independent 
• Simultaneous 
• Sequential 
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• Supportive 
 
Figure 1: Degrees of collaboration in industrial scenarios [6] 
 
As shown in this figure, the first scenario shows us a Cobot and Operator working 
independently doing different manufacturing process for a different work piece. 
According to Zaatari, Marei and Usman et al. [6] & Bisen and Payal et al. [7] , the 
interactive aspect results from the inclusion of the robot in the same workplace along 
with the operator; there is no barrier of space or force keeping someone out. Safety is 
provided by a robot’s inherent safety, or by incorporating hardware or software 
elements that add to the robot’s or expand the machine’s safety. 
 
The second one is related to a Simultaneous scenario where the Cobot and Operator are 
working in different processes for the same work piece at the same time. For this case, 
does not matter how long it takes for each of one to complete their tasks because there 
is no time or task dependency between them [6]. The only thing that matter is how far 
the cobot and Operator are from each other; It also does not matter where the work is; 
only that the robot is aware of the operator’s requirements [7]. 
 
The third scenario is Sequential; the operator and the cobot perform sequential 
manufacturing processes on the same work piece. These processes have different time 
constraints, which creates temporal dependencies between the cobot and the operator. 
In most cases, the cobot is arranged to handle tedious processes to improve the 
operator’s working conditions [6, 7]. 
 
The last scenario is a Supportive way, where an operator and a cobot engage in the 
same activity at the same time with one another, supporting one another. It is important 
that the operator and the Cobots work together as a team to achieve the result [7]. There 
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is dependency between the actions of the cobot and the operator, which means that, 
without one, another cannot perform the task. The cobot needs to understand the 
operator’s intent and the task requirements to provide appropriate assistance [6]. 
Table 1: Some examples of Human-Robot Collaboration scenarios 
Scenario Human Task Cobot task 
Drilling [9] The drill location is specified by 
operator, during run-time 
The cobot drills at the location 
specified by the operator, while 
movement is restricted to the drill 
axis. 
Surface Finish [9] 
 
The human specified surface to 
sand. 
The cobot sands the surface, while 
having motion automatically 
constrained parallel to the surface. 
Screwing [10] The human inserts the screws in the 
holes 
The cobot tightens a bolt om each of 
inserted screws, while the human 
maintains it on the flank 
Pick-and-place [6] The human chooses objects 
randomly to pick and place. 
The cobot chooses objects to pick 
and place while accounting for 
distance, reachability and the 
human’s predicted motion plans. 
Inspection [6] The human screws bolts in holes The cobot inspects if all holes are 
screwed and issues a warning in case 
of missing bolt. 
 
3.2 Safety measures for Human-Robot Collaboration 
 
The main technical narrative surrounding cobots is that their improved safety features 
allow them to be safely operated near human workers without fences or cages [3]. So, 
the safe coexistence between humans and robots is linked to careful planning and 
implementation of technologies that minimize risks and optimize interaction, ensuring 
the health and safety and well-being workers. 
 
In order to make it safe, the collaborationsamong Human-Robot are necessary to put 
in practice some safety measures. Based on the criteria outlined in ISO 10218-1 (2011) 
which is related to Safety Requirements for Industrial Robots, this criterion specifies 
requirements and guidelines for inherent safe design, protective measures and 
information for use of industrial robots [11]. The categorisation for collaboration is 
defined mainly from the perspectives of the safety strategy and the spatial relation 
between a cobot and a human operator [6], that is: 
• Safety Monitored Stop: A cobot operates normally on a work piece in a well-
defined workspace. Work will be disrupted when an operator gets access to 
the workspace, the cobot completely stops so that the operator can perform 
operations on the work piece, and the cobot will only restart working on the 
piece when the operator leaves the workspace [6, 7]. 
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• Hand Guiding: A cobot is compliant and moved manually by a human. This 
allows intuitive easier path teaching. It makes complex and interactive 
collaboration possible [6]. 
• Speed and Separation Monitoring: A cobot’s workspace is divided into 
zones. The closer a human operator gets, the slower the cobot moves. The 
cobot reaches a complete halt at a certain threshold [6]. 
• Power and Force Limiting: Cobots can be operated within limits of force 
and torque, and this keeps the operator from having to lift a heavy weight when 
they are making repetitive movements. An operator can be as spatially close 
to the cobot as needed without relying on external safety sensors [6, 7]. 
 
 
3.3 Cobot programming 
Just like us, human, cobot are also able to be instructed to perform specific tasks; it 
involves writing some cod or using specialized software. 
Programming, traditionally done by human programmer, involves giving the Cobot the 
ability to know the state of the environment in which it will be placed to perform its 
tasks and execute actions that advance the system towards a planned collaborative goal 
[7]. 
 
The programming features identified are listed below: 
• Communication: as we know, effective communication is the lifeblood of 
any organization, having a good communication among the workers, make it 
easy to boost productivity, and it is not different when it comes to a Cobot. 
Cobots are capable of receiving, recognising, and then responding to, when it 
detects a communication from the operator, which can be verbal (speech) or 
non-verbal (gestures, gaze, head pose) defined during the programming [6, 7]. 
• Optimisation: Important aspects of a cobot’s surroundings, such as obstacles 
and tool positions, are mathematically modelled as a function of the cobot’s 
actions. Those form cost functions that are optimised to generate desirable 
performance [6]. 
• Learning: Not just us, cobots also can learn new concepts, practise and give 
feedback about the result. A cobot learns a skill like how a human would, e.g., 
through observing demonstrations, trial and error, receiving feedback and 
asking questions [6, 7]. 
 
4 Conclusion 
 
 
6 
A Appendix 
The appendix should be positioned in front of the references. If it has been placed 
elsewhere, it will be moved by our typesetters. 
References 
 
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