Satakunta University of Applied Sciences has a Universal Robots 5 (UR5) robot arm, which is utilized for educational purposes by students as well as for school demonstrations. A demonstration that has proven popular at public events includes UR5 dispensing drinks. Through code, the robot is directed to use its machine vision to take a bottle from a bottle rack, pour the drink into the cups and drop the bottle into the trash. One major issue with this demonstration is that the bottles need to be manually opened. The number of drinks served at these public events range from tens to hundreds, depending on the audience, so it made more sense to use a machine for opening bottles.
This case was given to the students of the Robotics Academy to solve. After examining and analyzing the current situation, they discovered that the robot’s own grip strength was not enough to be able to spin the cap open and separate it from the bottle. The group responsible for this case mapped possible solutions, taking programming, mechanical and functional needs into account.
The biggest challenge was designing a gripper/opening head, which would suit the majority of bottle types and would also work for the robot, in terms of possible features. From the mechanical implementation point of view, the multifunctionality of the opening mechanism presented a challenge. The opening head had to rotate to remove the cap and then the cap had to be removed from the device before the next beverage bottle was brought to the machine. Used caps and bottles had to be deposited in the trash to make the presentation table ready for the next bottle.
The body of the device is constructed of an aluminum profile and the cage was designed from plexiglass. SolidWorks -3D design software was used to design mechanical parts, each track and gear carefully modelled to fit together. When the models were ready, they were printed on the school’s 3D printers. We chose biodegradable and inexpensive PLA plastic. In this way, making the new parts was as easy with the ability to print more parts, if needed.
For programming the opener, we chose Ardo’s Uno. It is a small microcomputer that is programmed in C ++ programming language.
The working solution: The robot takes the bottle under the opening head and the attachment removes the cap. The necessary equipment was made to place the removed cap in the garbage. We tested the operation of the device, and after the adjustments we got it to work consistently.