I'm looking for an easy way to tell me if the gripper has a part or not

scasey19 2017-03-20

what is the exact programming code to determine if the robotiq gripper has a part or not.

I want the robot to stop if it does not detect a part.

Annick_Mottard 2017-03-16

@scasey19 you can use the script command "rq_is_object_detected()". It returns True if an object has been picked or False otherwise.

All the script functions you can use are found in your instruction manual section 4.8.2. Note that you have some other interesting features described there. For example, you can also get a feedback on the size of the object you have picked.

Post below if you have more questions!

scasey19 2017-03-16

Thanks for the suggestion, but I tried this and it didn't work, I am picking up a very small part so the gripper is very close to closed even with a part.

matthewd92 2017-03-16

@scasey19 There is a minimum size that is required to be detected, how thin is the part you are trying to detect? Do you need the full opening width of the jaws on your application?

scasey19 2017-03-16

the distance between closed without part and closed with part is about .020" (.50mm)

matthewd92 2017-03-16

The minimum thickness that can be reliably detected is 1.2 mm according to this thread. If you are opening and closing your gripper all the way each bit in the register results in moving the gripper approximately .39 mm for the 2F85 and 0.65mm for a 2F140. If you could limit the amount the gripper is opening and closing you still get the same number of steps but they would now be a thinner slice, for instance if you limited the gripper to 20mm each bit in the register becomes approximately 0.17mm and may help you to register if you have a part or not, hard to say though without trying it.

David_Gariepy 2017-06-02

@scasey19
I don't know if you still need this but we just released a program template that contain a CAD of custom fingertips that will allow you to detect a part of any size. Check the post here

Best regards

RodWong 2017-07-12

Is there a way to change the threshold of the "object detect" function? The gripper is having trouble detecting a soft plastic part consistently. Sometimes it errors out thinking it doesn't have the part, but in fact it does. I do understand some of the problem has to do with consistency of the plastic. I can only increase the force or position to a certain point before breaking the part.

David_Gariepy 2017-07-18

No, it is not possible to change the threshold. But you could check using the current position of the finger to see if it is fully closed.
When using full force and speed, the position of the finger is 230.
If you are using low force and speed, you might need to change to lower the count a bit. may be 227, 226.

it would work somewhat like this:

if rq_current_pos()<230
  part_detected = True