Many companies do not use cobots for assembly because they are too difficult to adjust. A new research project will develop robot technology tailored for small-scale production, where cobots can be easily instructed in new assembly processes.
Although the development of cobots and easy integration is in full swing, it is still difficult to reprogram cobots for assembly processes. This is primarily due to the fact that there are many small tolerances and force effects between robots, workpieces and fixtures that need to be taken into account. Therefore, many assembly processes with frequent adjustment are still performed manually.
In this project, which is supported with DKK 10.5 million by the Innovation Fund, the University of Southern Denmark, Universal Robots, Terma and the Danish Technological Institute will develop a robot technology to meet this problem - specifically targeted at small series sizes. The project is named PIRAT, which stands for Programming Ignition for Robotic Assembly Tasks.
- In many productions with small series sizes, we unfortunately still see a low degree of automation, especially in assembly processes. It simply does not pay to automate, because companies then have to get hold of an expensive expert to program or adjust the robot process when a new item is to be produced, says Technology Manager at the Danish Technological Institute, Mikkel Rath Hansen.
It is very easy to program a cobot to move items from one place to another. This can be done, for example, by grabbing the robot and dragging it to the positions where it should pick up and bring the items. It immediately becomes more complicated when assembly processes - and thus contact with the surroundings - are involved. And the Danish production companies that have invested in cobots know this well.
- The goal is for everyone to be able to code our robot. It is coded for new tasks by an employee grabbing the robot arm and physically showing the robot the desired action. The computer stores the pattern. Maybe the action needs to be repeated a few times before the robot is completely sharp on the desired action, says Anders Billesø Beck, Innovation Manager at Universal Robots.
Assembly processes are very common industrial tasks, yet are only automated to a very small extent - especially in the typical Danish production, which is characterized by small series and frequent updates.
The robot must learn from its mistakes
The overall goal of the project is that an unskilled employee should be able to program assembly processes by guiding the robot through the process - very similar to what is possible for simple operations today. The robot must also continuously learn from its mistakes and adapt the process.
- Part of the technology's stability lies in the fact that force sensors measure whether the robot guides the pieces correctly in the assembly process. If the robot misses the spot when it has to put two things together, the sensors notice and send information to the robot's computer, so the robot is adjusted and hopefully is more accurate in the next attempt, explains associate professor at the University of Southern Denmark Christoffer Sloth, who is project manager for the project.
During the project we work with Terma on assembly processes with increasing complexity, from click assembly of components, to screwing and deburring. The project's results and the tools developed are continuously demonstrated and evaluated at Terma, where employees can try out the new tools.