Axis Compliant Linear Insertion

MendellSB

I am wondering if anyone has a good way to do a linear insertion with compliance in the other axis. I have a long round part that I am inserting into a collet up to a stop. The problem I am having is the part is so long that if the part is not perfectly aligned with the collet the part can bind on the way in. What I would like is to have the robot move in one direction (in this case X+) until it reaches the stop but I want the other axis (Y, Z, Ry, Rz) to be able to float a bit to accommodate any misalignment. The Force Control feature looks like what I want but I can't use the insertion function within the Force Control. Any ideas?

bcastets

@MendellSB
I would recommend to:

1. make sensor zero before starting insertion
2. use an insertion node to insert the little portion of the part (3mm, 10mm,... depending of what you can manage)
3. Use a force control node to push to the bottom while giving rotation compliance

Here below are suggestion of settings for a vertical insertion.



Sometime waiting in a force control node with compliance and help to align the part with the hole before pushing toward the bottom.

That being said correcting alignment for an insertion is a challenging task.

MendellSB

@bcastets

Thanks for the feedback. I was experimenting a bit more with it yesterday and came to the same conclusion. It would be nice to be able to jump out of the force control function after reaching a set force but using the the wait command seems to be working. Having the extra compliance helped make the insertion a lot smoother.

In my case I am pushing in the X+ direction so I made the Force 20N and set the deviation range to -0 to 150 mm. For me setting the stiffness of Y, Z, Ry and Rz to 50% worked well. I also set the limits for Y, Z to +/- 3mm and the limits of Ry and Rz to +/- 1° to prevent any extreme moves. My part actually starts about 3mm from the collet and the collet has a healthy chamfer on it. By setting the deviation limits pretty low I was able to insert the part completely without using an Insertion feature before the Force Control feature.