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Speed limits: does RoboDK know not to exceed robot joint speed limits?
#1
Hi, 

I am new to RoboDK, and am wondering whether RoboDK stores information about robot joint speed limits in its robot models, and whether it knows not to exceed them when planning robot motions. 

For instance, I'm looking at milling a piece using the ABB IRB 6700, which lists maximum axis speed for axes 1-6 in deg/sec as [100, 90, 90, 170, 120, 190]. I'm using the robot machining functionality, which sets speed to say 1000 mm/s for a certain operation. I take it this is speed of the TCP. Does RoboDK calculate the resulting speeds at each axis and check that those are within limits? 

Thanks!
#2
Hi JCC,

It's a good question, but kind of a trick question.
RoboDK don't really need to know the speed limits of each joint, this is mostly the job of the robot controller.
It's especially true for machining projects.

Machining projects are composed of a high amount of MoveL packed together. Therefore the linear speed is more important than the angular speed.
Once the robot controller receive a TCP speed, let's say 1000 mm/s, it will TRY to reach that speed. I say TRY because it can possibly be limited by external factors like "acceleration and deceleration ramps" or by the speed limit of a joint. In other words, the controller will try to bring the TCP to a speed as close as 1000 mm/s, but won't go faster than that.

By the way, it's the exact same behavior as what you would get if you were to program your ABB robot manually.

Have a great day.
Jeremy
  




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