How to Determine the Best Motor Speed and Minimum Interval for a Stable MDO Simulation

Hi everyone,

I am simulating the attached link mechanism (car seat flip-up with leg folding) in Creo MDO.

(To get operating torque for seat flip up at each angle)

However, the measured motor torque varies significantly depending on the flip-up motor speed and the minimum interval settings.

In my current model, I observed the following: 

 Motor speed: 10 deg/s
 Minimum interval: 1 to 0.01
 Result: Motor torque oscillates significantly.

 Motor speed: 1 deg/s
 Minimum interval: 1 or 0.1
 Result: Stable torque results.

 Motor speed: 0.1 deg/s
 Minimum interval: 1 to 0.01
 Result: Simulation fails because the slot connection breaks.

Based on these results, it seems that using a slower motor speed and a smaller minimum interval does not always improve simulation stability.

Could anyone explain why this behavior occurs and share any recommendations for improving the stability of MDO simulations? Any best practices for selecting motor speed, interval settings, or other solver parameters would be greatly appreciated.

(I was able to find a set of conditions to run successfully. However, I would like to better understand the underlying factors affecting simulation stability so that I can troubleshoot similar issues in future models.)

Thank you in advance for your help.