**2. New era of industrial robots**

Robotics has played an essential role in manufacturing industries for so many years. They are tough, fast, and very accurate to perform specific tasks. In terms of speed and accuracy, robot performance is way much better than human workers. However, those robots have left significant gap because it takes hundreds of hours to program [30]. They are employed mainly for specific tasks that involve dangerous tasks and monotonous operation with great precision. Some of these applications are paint and sealant applications, welding, assembly, material handling, inspection, and so on [31]. In old-fashioned and traditional robot in industries as depicted in **Figure 2**, the working space of robots are isolated from human workers because it may harm humans if they work near robots or within the working area of robots. At present, with advanced robotics technologies, humans and robots can work side by side collaboratively. The collaboration between humans and robots is still in primitive way, in the sense that the robot is able to detect collision or foreign object and then a corresponding response is executed, for example, by reducing its speed or stopping immediately. Another collaborative robot such as Baxter robot which

**Figure 2.** *Conventional automation factory using KUKA robotics [33].*

#### *Computer Simulation of Human-Robot Collaboration in the Context of Industry Revolution 4.0 DOI: http://dx.doi.org/10.5772/intechopen.88335*

is designed as an industrial robot can work very closely with people. However, the precision of this robot is still limited [32], and for now it cannot compete with other popular industrial robots, for example, KUKA, ABB, FANUC, Universal Robots, etc., in terms of repetitive tasks. Nevertheless, the usability of this robot is its suitable application as a robot assistant in which the precision can be tolerated.

Collaborative robots are also known as cooperative robots, cobots, or robot assistants [30]. They are mechanical devices that provide guidance through the use of servomotors, while a human operator provides motive power [34]. Generally speaking, it can be denoted as a robot that works side by side in a safe way either with another robot or with human workers to complete specific tasks. Thus, safety and productivity are the two important issues and become the main factors for design of robotic collaborative behaviors [35]. In human-robot collaboration, this behavior is related to how robots react when human physical contact occurs during execution. On the other hand, human-robot interaction in the general sense is a study of robotic systems for use by or with humans which concern with understanding, designing, and evaluating robots [36]. In physical human-robot interaction, human safety is the main concern and must be considered when evaluating robot setups in a workspace [37]. This interaction is related to a form of communication whether the robots and humans are positioned near to each other or not. Obviously, this interaction term does not necessarily mean collaborating, but merely how the two parties are communicating or interacting with each other in a certain way, while the other term means working together to achieve shared goals. Although these two terms are different in meaning, the human-robot interaction in fact can be used for collaborating. Thus, human and robot collaboration stands between the lines of manual manufacturing (where humans work manually) and full automation (where robots work independently) [30]. By collaborating between humans and robots (or machine), it is widely known that they become more productive than if each party work individually.

Collaborative robots at least have several elements, namely, the ability to detect any object within its work space and then react in order to prevent any collision [30], flexibility and situational task sharing [34], and cooperation on a mutual workplace [34]. These three elements differentiate collaborative robots from traditional robots even though the appearance between those industrial robots is the same. Their structural forms of multi-degree of freedom (multi-DOF) are intended to have the capability of reaching every specific coordinate of their workspace. In the case of task complexity or challenge situation, the collaborative robot tends to have more joints, for example, as given in **Figures 3** and **4**, that is, ABB YuMi IRB 14000 has 14 joints in total or 7 joints for each arm, while KUKA LBR iiwa has 7 joints, respectively. The structural models are reasonable because collaborative robots are designed to be ergonomic. For robotic system with many joints, the complexity of such control system becomes more difficult. Thus, research in control system for such robot is challenging problem.

The competition to bring up the elements of industry 4.0 is still under way between companies in Asia, Europe, and America [38]. There are two successful robotic implementation in industries that link to industry 4.0, namely, robotic application in automobile factories of BMW and Tesla [14]. In BMW group factory, the autonomous mobile robots are used for smart transport systems in supply logistics, while KUKA collaborative robots are utilized to work side by side with humans, for example, for lifting and positioning heavy components and welding operations [39]. On the other hand, Tesla's factory also has utilized robots with other technologies in their production lines to support smart and intelligent products [14]. One example is the use of industrial robots for repetitive tasks such as applying an even layer of paint for automobiles. For several types of repetitive tasks, fully automated production with robots is chosen instead of human workers, but for other specific

*Becoming Human with Humanoid - From Physical Interaction to Social Intelligence*

**Figure 3.** *ABB YuMi IRB 14000 [40].*

tasks, human workers can not be replaced by robots because humans have skills, knowledge, and intuition. Which tasks that should performed by robots or human workers must be analyzed, otherwise the robot utilization in the industry can lead to production delays [39]. Indeed, robotic technologies must be incorporated with

#### *Computer Simulation of Human-Robot Collaboration in the Context of Industry Revolution 4.0 DOI: http://dx.doi.org/10.5772/intechopen.88335*

any other emerging technologies to improve efficiency and productivity, but this utilization must be well prepared, properly designed, and carefully implemented for end-to-end production lines.

The collaboration between humans and robots is a new shift in industrial and service robotics as an element of strategy for industry 4.0 [30]. This strategy has a goal to set up a secure environment for human-robot collaboration. The framework for safety in industrial robot collaborative environments can be found in [20] where CPS is currently included as part of recent development in intelligent manufacturing. The use of CPS helps to bring the sharing of workspace for human-robot collaboration. The shared workspace of robots and human workers can be illustrated in **Figure 5** in which there are three possible configurations: (a) Isolated workspace where robots must be put in a cage in order to prevent any harm to human workers. (b) Some part of the area is shared among humans and robots. (c) Fully shared workspace where humans and robots work side by side to perform several tasks. In the first scenario, there is no interaction or whatsoever between humans and robots when the robot is in operation, while in the last scenario, the human worker may have contact or interaction with the robot in a safe way. Due to safety issue, the robot in the first scenario can be programmed faster than the robot in the last scenario. Thus, these three different scenarios must be designed and evaluated when they are utilized in industry so that the utilization can yield higher efficiency and productivity. This safety issue was also the subject of investigation for the critical requirements of fenceless implementation in human-robot collaboration, specifically in automotive application where the robotic system can be divided into three levels of complexity [42]. However, the new technology capabilities as suggested in [42] are already realized in collaborative robots that are built today.

The humans and robots in **Figure 5(a)** and **(b)** are not interacting with each other. On the other hand, in **Figure 5(c)**, the interaction at least is limited with physical interaction [43]. Human-robot interaction is related to communication between humans and robots whether it is remote interaction or proximity interaction [36]. The elements of human-robot interaction which consist of task structure and user attribute as discussed in [44] probably can also be investigated for future technology in human-robot collaboration. Although this research discussed in [44] is applied in ASIMO (humanoid robot), the research probably can also be implemented for collaborative robots, for example, Baxter robot and ABB YuMi. Some

#### **Figure 5.**

*Illustration of shared human and robot workspace [30]. (a) human worker is totally separated with robot workspace, (b) human worker is partly shared with robot workspace, and (c) human worker is fully shared with robot workspace.*

**Figure 6.** *OTTO 1500 self-driving vehicle [46].*

research have been conducted to incorporate the human-robot interaction with human-robot collaboration to increase the productivity in completion of tasks.

On the other hand, mobile robots have become more compliant with human workers in factory. They work autonomously with self-driving and are able to detect obstacle and be aware of human existence. Some of the examples are KUKA youBot [45], mobile industrial robot (MiR), and OTTO self-driving vehicle (SDV) [46]. **Figure 6** shows OTTO 1500 SDV in which the robot is designed to move pellets, racks, and other large payloads through dynamic production environments with the ability to carry maximum load of 1500 kg. The combination between manipulator and mobile robots for one system can also be found in mobile robot KMR iiwa and mobile manipulator robot CHIMERA. Another form of collaboration between humans and robots in industry application for different tasks such as lift assist or hands on payload can be found in iTrolley module system [47].

In traditional industrial robots, there are several different modes in programming robots, namely, physical setup, lead through or teach mode, continuous walk-through mode, and software modes [2]. In software mode, there are two different approaches, namely, offline programming and online programming. In offline programming, robot simulation is used and set up in advance, while in online teaching, real robot is employed to generate robot program [48]. On the other hand, in collaborative robots, the user may program collaborative robot using task-level programming software tool which is developed based on robot skill concept [48]. The robot simulation as mentioned in programming real robots is totally different from programming robot in robotic simulation studio such as Marilou. In Marilou, the robot model is developed from scratch, and each joint with actuators and sensors is defined, and then, the controller system is designed and implemented using specified language programming. Thus, the robot programming in robotic simulation studio like Marilou is more flexible for different robot models and applications.

**Figure 7** shows a robot that is the so-called Baxter by Rethink Robotics. It is a semi-humanoid robot with limbs of 7 DOF joints to form a dual-armed robot. This robot is a type of industrial robot with several unique features which include the safety for collaboration with human, user-friendliness, ability to train manually with no programming required, and ability to respond to a dynamic environment [49]. The advantage of collaborative robot such as Baxter is the ability to adapt to circumstances because the robot can be adjusted and applied to different applications by reprogramming the robot quickly. Another latest similar version from Rethink Robotics with only one arm is Sawyer. Baxter and Sawyer are both collaborative robots where they can work side by side with human workers and adapt to real-world variability in semi-structured environments.

*Computer Simulation of Human-Robot Collaboration in the Context of Industry Revolution 4.0 DOI: http://dx.doi.org/10.5772/intechopen.88335*

#### **Figure 7.** *A collaborative robot: Baxter robot [52].*

Some research have been conducted which involved Baxter robot for various applications and problems. For example, manipulation-based assistive robotics [50], performance assessment for point-to-point motion problem [32], and collaborative manipulation of a deformable sheet between humans and Baxter robots [51]. It is suggested that Baxter robot has a good potential for future robotic applications for home services or industrial applications.
