Companies engaging in manufacturing complete products most likely have an assembly line. This is where they assemble, screw, glue, seal and insert all the different parts together to make a final product. However, as the workforce ages and workers get harder to hire, it can get tougher for the present workers to complete the task at the required pace.
Assembly tasks are therefore becoming more and more automated. With the introduction of robots from Universal Robots that can work alongside workers, the human-robot collaboration is indeed a step up. It is now easier, less risky and a lot faster to use a robot in the assembly lines in order to increase the overall productivity.
A collaborative robot or cobot for short is a robot that is used without safety guarding which means it can be put beside a machine or a person and set to perform a certain task without needing to be fenced off from the surrounding environment.
What to consider when using Collaborative Robots in conducting assembly tasks
That being said, to introduce a collaborative robot to an assembly line and program it to load and unload parts is not as easy as it sounds. One needs to choose a cobot that can accomplish the task while reaching a higher level of performance compared to a human worker.
The robot has to be consistent in its assembly motions in fact, with fragile parts like PCBs (printed circuit boards) there is need for a high repeatability so as to produce quality products and to avoid damaging the parts during the assembly process. In order to accomplish this one needs to choose an ideal robot assembly that meets the application needs in terms of repeatability.
When using the cobot, workers should think about the robot as only having a single arm. This means it needs a mechanical stop to secure one of the two parts being assembled. This jig maintains the repeatability of the assembly process.
The payload is the total weight the robot can comfortably carry. It is therefore very important to weigh your tool and the heaviest part you want to carry in order to determine the robot’s payload.
You ought to consider the power tools or other kinds of tools used. The tools may have a relatively high mass but the robot has to match or exceed this payload. When applying force on a part, you should respect the cobot’s maximum rated payload.
The collaborative robot will at times need to pick a part from somewhere and place it somewhere else (pick and place). One then needs to measure the distance between the two points and divide it by 2. This gives you the minimum reach the cobot must have.
For a large reach, the payload will automatically increase since a larger robot is a stronger robot. When screwing a part ensure the robot has an infinite rotation at the wrist.
The collaborative robot works safely alongside humans but it’s still important to perform a risk assessment before starting up the robot since they still represent some degree of danger. Remember that even if the cobot are safe, if it is carrying a sharp object then ultimately it can still be dangerous.
One may want to move the robot from time to time especially when changing production. Collaborative robots usually use 120V electrical power directly connected to the socket. This means one can move it wherever they want with a rolling base.
All that is needed is plug it in at the new location and adjust the programming for that specific process. Always make sure you secure the position of the cobot if you want it to be repeatable. If you also want to keep on moving the robot to a given number of fixed locations ensure there are mechanical stops or anchors to clip the cobot.