Hello,
I want to read the value of the force applied at the gripper when it close and open with a part and without part.
I tested using function get_tcp_force, the values are keep changing. No constant value to tell what is the force.
How can I measure the force value applied when robot pick the part?
Thank you
If you’re trying to determine how much clamping force your gripper is asserting, you’ll have to figure that out on your own if it’s not already provided. It would come down to reading the torque or pressure or something of the actual servo/motor/valve/vacuum/etc.
If you’re just trying to figure out if a part is gripped or not, you can likely use the “force()” expression to do so. You’ll first want to run the “zero_ftsensor()” script command to tare the sensor prior to picking the part. Then after picking, the force() command should have a value above 0. You’ll still notice minor fluctuations, so you’ll want to set your logic to something like “if force() >= 1” or something. Something significantly above the background noise so you don’t get a false positive.
Thank you for the reply.
I tried, below is the program I used:
Robot Program
- Gripper Open
- zero_ftsensor() (script)
- MoveJ
- Waypoint_1
- Waypoint_2
- Gripper_close
- Wait 1.0
- Waypoint_1
- var_1:=force()
When I tried this, I can see the value of force but it is fluctuating, such as 1.28931, 0.80439, 1.43469, 1.30844, 1.26084, 1.41728, 1.28007, 1.03932, 0.99602…
Is the result going to look like this only?
Is it possible to make it some stable?
Thank you
I would run my zero_ftsensor() immediately before closing the gripper, followed by a very short wait, per the manual’s recommendation. They recommend a wait of 0.02 seconds after issuing a zero_ftsensor() command. Then move up to your waypoint and check the force like you’re doing. I would advise you do this both with and without a part so you can see the difference in values (if there is one). If your part is not heavy enough to produce a noticeable value, you can optionally choose to move straight down until tool contact, then check how far you’ve gone. If there was no part in your gripper, you will have traveled down farther. You should be able to use this as a distinct value, but it would add cycle time
This helped. Thank you Eric