Linear Mover and MoveL speed uneven even though set equal

zzon0nozz

Hello,
my problem is that the speed of the smart component Linear mover and the speed of MoveL arent the same even though I set them equal.
I'm using a Linear Mover with a speed of 1.7mm/s to move an object. I am trying to follow the corner of this object so I did a Path witch goes in the same direction and with the same speed as the object. The Path starts as it goes through a plane sensor, activating "MARCHA"
        MoveL Target_80,v1000,fine,MyTool\WObj:=wobj1;
        WaitDI MARCHA,1;
        MoveL Target_90,vmax\V:=1.7,fine,MyTool\WObj:=wobj1;
I have tested it with 100mm/s (MoveL v100 and the linear mover to 100) with same result. The MoveL is always a bit faster than the object moved by the linear mover.

Can someone explain me why this is so? And maybe how can I get to follow my object accurately?

Best regards,
Lucas Ernst

Pavel Riabichev

Can you upload a pack and go that shows the behavior?
You have to rename it to .zip to be able to upload.

zzon0nozz

Of course, thank you for the fast response.

Pavel Riabichev

Hello
My guess is that the speed calculations for linearMover are done with less precision than the robot. This for the sake of performance since we can have many of these components in a station and that could cause lag.

Your cell looks like a conveyor tracking application. Conveyor tracking is possible in RobotStudio so you should try it for better results. Check the RobotStudio manual for conveyor tracking.

In reality, you would get the same problem following an object by simply setting conveyor and robot speed to the same. This is why there is conveyor tracking option that uses an encoder to sync the speed.

/Pavel

zzon0nozz

Hello,
yes you are right, it is a conveyor tracking application but the problem is that we don't have an encoder at out station. That's why I am trying to simulate it without the conveyor tracking. In real life we use controllers to maintain the speed but I'm finding difficulties doing so in the simulation.

My second thought was to use the conveyor tracking option, to get the object moving, and put the path in an other worktobject (not using the tracking system). This leads to the same problem, the conveyor is slower than the robot.

My only solution so far is to gradually set the speed of the conveyor a bit higher so that they eventually move at the same speed. This happens for: Robot set to 100mm/s and conveyor to 100,8mm/s.

Is there no other way to get the conveyor speed set exactly as I wish?

Best regards,
Lucas Ernst