# Experimental Study of the Vibrations of a Roller Shutter Gripper
## 5 Conclusions  
The article presents a study of the characteristics of a roller shutter gripper on a robotic patletizing station. The gripper developed by the authors is dedicated to handling whole layers of products, separators, and pallets. A PLC, which is an integral part of the device, is responsible for the correct operation of the gripper. The PLC's software allows the realization of tasks (handling of products, separators, and pallets) using information from sensors. Communication of the gripper with the robot was implemented via Ethernet.  
Property tests of the developed and built gripper were carried out using a FANUC robot, a vision system and XSENS triaxial sensors. The testing methodology suggested by the authors allows verification of the stiffness of the design and the influence of changes in the robot's motion parameters on its behavior at process points. The presented test results confirm that as the robot's motion speed decreases and the _ACC_ coefficient decreases, the occurring vibration of the gripper structure decreases.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Test No.**} & **Robot Target** & \multirow{2}{*}{**ACC**} & **Maximum Horizontal** & **Maximum Vertical** \\  & **Speed** & & **Displacement** & **Displacement** \\ \hline  & (mm/s) & (\%) & (mm) & (mm) \\ \hline
1 & 4000 & 100 & 0.47 & 0.42 \\ \hline
2 & 3000 & 100 & 0.42 & 0.42 \\ \hline
3 & 2000 & 100 & 0.30 & 0.21 \\ \hline
4 & 1000 & 100 & 0.18 & 0.12 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Maximum gripper displacement for selected robot speeds.  
Figure 23: Approach of the robot to the process point. \(P1\)—start point, \(P2\)—process point, \(P3\)—intermediate point, \(V\)—linear speed of the robot, _ACC_—acceleration coefficient, \(Vd\)—approach linear speed of the robot to the process point, _ACC_—acceleration coefficient to the process point.  
A robot with a higher structural stiffness compared to the gripper shows a change in the maximum acceleration value for the measuring point on the flange. For the measuring point located on the gripper, a disturbance in the decrease in the maximum acceleration value can be observed. This happens when the maximum velocity and the acceleration coefficient (\(ACC\)) change. This could be the result of the appearance of the structure's own vibrations, which have a fading character but are not monotonous.  
The results obtained can be used to support programmers in designing the robot's motion path and selecting downtimes at process points. By adding an additional crossing point, where a change in the motion parameters (speed and acceleration) would occur, there would be an opportunity to effectively reduce vibrations.  
The conducted research proves that the use of triaxial XSENS sensors and high-speed cameras allows to effectively perform determination-related analyses. In further work, the authors will focus on the possibility of using the proposed analysis technique to reduce vibrations of selected robotic manufacturing processes (e.g., spot welding).  
Conceptualization, S.B., W.K. and J.P.; methodology, W.K., J.P. and S.B.; software, P.P., S.B. and W.K.; validation, W.K. and J.P.; formal analysis, W.K. and J.P.; investigation, W.K., J.P., S.B., M.S. and P.P.; resources, W.K., J.P., S.B. and M.S.; data curation, W.K., S.B. and P.P.; writing--original draft preparation, W.K. and S.B.; writing--review and editing, S.B., W.K., P.P., M.S. and J.P.; visualization, W.K, M.S. and P.P.; supervision, W.K., J.P., S.B. and P.P.; project administration, W.K. All authors have read and agreed to the published version of the manuscript.  
This work was cofinanced by the Military University of Technology under research project UGB 893/2021.  
Not applicable.  
The authors declare no conflict of interest.