set the decelerate

weisheng

hello, everyone

We know that the velocity of robot move from p1 to p2 is accelerate ,constant speed and then decelerate.

I want to set the decelerate to zero. 

It's mean that  robot moving to next position is only accelerate and constant speed.

How to do it? 

thanks

shahaboid

I would be interested in knowing that as well. Speed is a very sensitive parameter in our process and having full control on that is critical. 

weisheng

For now, I use the instruction,"PathAccLim".

It can set the deceleration to limit, 0.5m/s^2.

But it also has the deceleration.

So, Does anyone know to do this?

Marcel

Hi

If you use a zone (not fine) the robot doesn't stop and decelerate exept for the kinematik if the path has a other direction at a high speed. You can even use z0 to go very close to the position p2.

Best regards

Marcel

John Wiberg

I would say that the answer would be very process specific, as in, what is it you do at the targets, before and in between? Then also the angle between the targets at the position where you want to keep the speed. And whether the process is linear motion only or if it allows some rounded motion.

 

As Marcel said, the ordinary way to do this would be using zones. But with that it would still be normal to have a deceleration when the robot switches direction. So it would depend on angle and process. Also depending on that, it could be solved with a curved motion (MoveC) in the "corner", if the process allows that.

 

There is a great tool in RobotStudio where you can detect speed. If you turn on the Simulation Monitor you can set Alerts for speed. You can get the Alerts both visually in the graphics using the trace function so that you can see exactly where among the targets you are below&above the threshold and get a readout in the output window as well.

I've recommended that approach several times for paint projects and got very good feedback on the costs saved.

So you could test different solutions offline before trying them out online.

 

John Wiberg

By coincidence this weeks blog post was about zones.

http://www.abb.com/cawp/gad00540/592a8dba95ea8b0ac12579dc006fec12.aspx?single=1

note that on top of that information the program pointer executes the next line as soon as it reaches the zone. So if I have

Move to p10- with zone

Set IO

Move to p20

the IO will trigger the zone distance from p10.