Levels of Collaboration Case Study: Sequential Collaboration
- Post By : Zeta Group Engineering
- August 26, 2022
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Human/Robot Collaboration
The future of robotics and automation is not about replacing workers with robots. Instead, it is about allowing humans and robots to collaborate efficiently to improve manufacturing lines.
Collaborative robots (or cobots) are one prominent example of how humans and robots collaborate. These types of robots allow the two to work side by side without additional need for safety sensors or scanners. This is because of the internal safety of the robot.
However, automated solutions that include industrial robots can have collaborative features as well. These systems utilize other measures to ensure that the worker is collaborating safety. These include, safety scanners, light curtains, and hard fencing with interlocking doors.
Levels of Collaboration Between Humans and Robots
In a previous blog post we described the 5 human/robot levels of collaboration. Simply stated they are:
- Fenced Robot
- Coexistence
- Sequential Collaboration
- Cooperation
- Responsive Collaboration

Case Study: Sequential Collaboration
In a recent project that Zeta Group Engineering designed, built, and installed for a cheese manufacturer, a part of the system included sequential collaboration.
What is Sequential Collaboration?
Sequential collaboration is the middle level of collaboration. It occurs when a worker and robot utilize a shared workspace, but each occupies that workspace at separate times.
Typically, the robot will utilize safety rated electrical scanners and controls to know when to occupy a space and when to not occupy a space.
Real Life Example
Zeta Group’s Zeus Automation Series is a fully automated depalletizing/palletizing solution. In this specific example, Zeus was depalletizing and palletizing frozen cheese cases that had freezer sheet layers and a base & riser layer.

The customer did not want to automate the removal of the base & riser at the moment. Instead, a worker is responsible for removing the base & riser manually.
The worker and robot share a workspace, but each occupies the space at different times. When the robot gets to the base & riser layer, it returns to a safe home position and a red light turns green. This signals to the worker that it is safe to enter the cell.
Once the worker removes the layer, they ensure the cell is clear and restart the depalletizing application from the HMI. The light turns back to red, signaling that it is not safe to enter the workspace and that the robot is occupying the space.
While the robot is running, there is an area scanner that monitors the non-fenced portion of the depalletizing cell. If a worker is sensed in the shared zone when the robot is using the workspace, the robot immediately shuts down and holds its position.

LEARN MORE ABOUT THE LEVELS OF COLLABORATION: https://www.zetagroupengineering.com/levels-of-collaboration-robots/
LEARN MORE ABOUT ZEUS AUTOMATION SERIES: https://www.zetagroupengineering.com/automation/zeus-depalletizing-palletizing-system/
