The previous chapters revolved around some important critical aspects concerning manufacturing work and the evident improvement brought by universal robot in different field of activity

The previous chapters revolved around some important critical aspects concerning manufacturing work and the evident improvement brought by universal robot in different field of activity. The next step is to integrate this solution in technological way in other word to use others technologies and different ideas in direct connection with industry 4.0 themes.
In this chapter, we will create different scenario with universal robot in order to deepen the knowledge of the cobot capacities. Also the collaborative robot work will be combined with other two important themes which are 3D printing and digital-twins.
2. Creation of Scenarios
Universal robot presents the centre of this internship and the main subject of this research. That’s why; we have dedicated a great time to run experiments and to realize projects touching directly the subject of industry 4.0 and its core element the “Smart factory”.
As UR5 represents a new technology in our lab, it was decided to test its capacities and figure out the possible opportunities that UR can create and provide for manufacturing in the future.

2.1. First Scenario: Difficult Movements with Variation of Speed
We wanted to test the capacity of universal robot to adapt to difficult movements while changing the speed of movement.
We came across a situation where the UR safety system was violated.
In order to avoid this problem in the future, we brainstormed the possible causes and other problem that may arise as follows:
1. Trying to move the robot in different and difficult angle while changing the speed can lead to serious damages on the robot
2. Bumping into hard surface leads to:
• Scratching badly the robot
• Broken joints
3. Joint position limit violation
• Non functioning robot ( impossible to turn it on)
The following figure4.1 shows the Safety message appearing on UR5 teach pendant screen when the violation happened in our labs.

Figure 4.1: Joint position limit violation message
4. Turning the robot arm in tight angle
• The electricity cable of UR can be easily disconnected from its position.
This figure 4.2 below illustrates some dangerous positions that can damage the UR5.

Figure 4.2: Joint position limit violation message

If the robot moves a little bit in its opposite direction, we can easily face the problem related to its cable disconnection which will lead to others dysfunctions and damages at the level of the connectors.
2.2. Second Scenario: Simple Movements with Variation Of Speed
For this scenario the robot will grab an object from point A to move it to point B as presented in the following figures 4.3 And 4.4. UR will perform the same action 3 times but each time with different speed, from slow to fast and fastest rate.

Figure 4.3: UR grabbing an Object from position A

Through each attempt, we have conserved the same motions only the way point was changed in order to match the location of each subject.
We can clearly sense the change of speed not only visually but also at the level of the robot joints, to be more specific the Shoulder joint while changing positions from the two points. It is clearly that the movement sound it becomes louder than the previous attempt.

Figure 4.4: UR5 second position B

When the robot becomes faster and faster, we can sense that this robot also has a similar powerful side like industrial Robot (example KUKA).
à This CoBot is still safer (due to security stop technology) but we need always to take step back to ensure the user safety while using UR in fast mode.
2.3. Third Scenario: Drilling using the UR5
In this Scenario, we are using a drill machine but with a pen on its end in order to test the precision of UR5. The use of pen as replacement for the real machine is to ensure the worker safety in the lab.
We will make a point in three consecutive circles: big, medium then small one (with a ray of 1.5cm the big circle) as shown in the following figures 4.5 And 4.6.
Through the test process, we have noticed that the work of UR is quite precise and barely occurs errors or change at the level of the marked point’s position.