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mikebeauchemin

@Sebastien thanks for sending some parts our way, it is always nice to be able to test our gripping solution on real industrial applications. I even took a video of my testing (see at the end of the post). Here are the steps that I did to evaluate your application:

1. Some books are rigid and others are just like a stack of paper which is quite soft. However, all books or stack of paper are sealed in a weak plastic shell. Suction cup is not an option because the plastic is too weak. It would just break apart when lifting.

2. Manipulating hardcover books seems no problem. When manipulating soft ones, the trick is to grab the pile with a wide and strong grip.

3. So I first decided to try with one 2F85 gripper, which is the strongest Robotiq 2F gripper and added some wide custom fingertips (See below). This works very good. The control that we have on the gripper’s positioning and force allows us to manipulate the pile just like a human would do. However, some stacks were too heavy for the single gripper.


4. Second option I looked at is using dual gripper mounted in parallel on the robot (See below). I used 2x 2F85 grippers but with the 2F140 fingertips because they are longer and would help get a stronger grip on the pile. For the real application I would consider manufacturing custom fingertips that would be long and wide to get a steady grip on a soft pile with both grippers. This setup worked very well. Again the control allows us to really mimic human grasp. 


Here are a couple of tips to watch out for in the real application:

The fit of the books in the box is quite tight. So you need to place the box accurately each time to make sure that positions are repeatable and that you are able to correctly place the books in the box. Once the book dropped in the box, you can close the gripper and move the robot to push against the book until it is correctly placed in the box. Using the UR force function at this point could be useful. Another key point would be the position where you pick the book from. The way I am thinking of doing this would be to activate 2 cylinder that would push the book in place such that it is always positioned the same and that the robot has access to pick the book from the side. Also note that I used the path recording function with the FT300 to program the path as the book is being placed in the box. This was the easiest and fastest way to program this trajectory that contains linear motion and some rotations as you lay the book against the bottom of the box. 

https://youtu.be/Xcjp-5Js2AU