[luminaaa]

I have recreated a real robot application (UR5) in RoboDK. I extracted the speeds and accelerations from the code of the robot. When I apply these values in the simulation (using set speed), the robot moves much faster than in reality, even though the time ratio is set to 1:1. What could be causing this?

My first guess was that it might be because blending is not shown in the simulation, but I don’t think this is really the issue. The speed difference between the simulation and reality is actually quite significant.
I can provide more information or the RoboDK file if that would be useful.

[Albert]

Did you enter the joint and linear speed limits as well as the acceleration?

Did you apply blending on both robots, the simulated one and the real one?

If you can share your RoboDK project file we can better take a look.

[luminaaa]

Yes, I entered the speed and acceleration values accordingly and also applied blending, both on the real robot and in the simulation. The blending is not visible though, but I read that this is normal?

Please note that the real robot was not programmed via RoboDK, but independently. My simulation therefore only serves as a replication and is not directly linked to the real system.

[Albert]

Thank you for sharing these details. You are correct that blending is applied in RoboDK simulations but is not visually shown, so that is normal. The important factor here is that RoboDK assumes the robot can maintain a constant speed when going through different points using blending. However, the real robot may struggle to maintain that speed and may reduce the speed in the viccinity of the targets where the change of movement happens.

I understand you loaded SCRIPT files from your UR robot controller in RoboDK? Can you send us these files? Did you override the robot speed with the teach pendant?

If you can provide these details we can better troubleshoot.

According to our testing (and assuming the robot can maintain the programmed speed and accelerations), the time estimates in the RoboDK simulations are very accurate for UR robot controllers (less than 5% error estimates in cycle time).

[luminaaa]

Thank you for your feedback. Please find attached the robot code. I have also included a video showing the actual speed of the robot. Please note that the speeds specified in the RoboDK file I sent you are currently not the same as those in the code. I intentionally reduced them so that the simulation speed would match the real robot’s performance. In theory, the simulation should run at the same speed as defined in the code, since the real robot also uses these values. I have additionally tested whether the robot might be operating in a safety mode with reduced speed, but this does not appear to be the case.