Grasp() doesn't detect Part & triggerCondition doesn't activate on GraspSignal

Python Programming
1

Hi everyone,

I’m trying to Grasp and move a cylinder which has been placed by a robot. Here I’m encountering 2 problems:

  1. I’m trying to trigger the Grasp() function through setting the grasp_signal to True in my PythonScript. Does anyone know why this doesn’t work? (I’ve commented this line in the PythonScript to work-around this and test the Grasp() function)

  2. When I activate the Grasp() function it doesn’t detect the Cylinder even though the TCP is inside the Cylinder. Does anyone know what the problem is?

Please find my set-up attached.

Hopefully someone can assist on one of these questions.

Kind regards, and have a nice weekend,

Niels

TestGrasp.vcmx (230.8 KB)

2

First raycast sensor does not detect part.

image
image604×668 8.64 KB

If I offset the raycast frame a bit on the X-axis, the signal of the sensor will fire.

image
image763×710 13.5 KB

Be aware that changing the value of a vcSignal with a setter does not trigger OnValueChange event. You should use the vcSignal.signal() method.

#grasp_signal.Value = True
grasp_signal.signal(True)

If you make that change and also comment out the delay then your cylinder is grabbed.

image
image892×1677 78.6 KB

If possible, please make things easier on yourself.

3

Hi Zesty,

Thanks for your response!

First, it’s interesting that you found that the Raycast sensor didn’t detect the cylinder because when I download the .vcmx file and open it, it does detect the cylinder. See image below. My VC version is 4.5.0.1 with Delfoi Robotics Software.

Raycast_Sensor2

Second, thank you for the advise on using grasp_signal.signal(True), I wasn’t aware of this but it makes sense!

Third, I adjusted the items as you mentioned but this didn’t seem to make it work completely. It wouldn’t Grasp the cylinder and when I moved the Joint the Cylinder wouldn’t move.

I found that when I adjusted the radius of the cylinder to 25 mm and introduced a delay(0.1) in the GraspActionScript it does work. See attached file. I feel like it might have something to with where the cylinder is attached to, after being released by the robot, and the location & detection volume at the TCP. Would you agree?

TestGrasp2.vcmx (177.6 KB)

Kind regards and hope to hear from you.

Niels Visser