This has been fixed for a while, but unfortunately the fix is not yet included in an official release.

If you contact me via email, I can send you a link to a preview release that includes the fix.

With regards to controllers: yes, it is possible to implement .scone controllers directly using sconepy. It is also possible to use .scone controllers in combination with sconepy. The advantage of the latter approach is that .scone controllers have higher performance than Python alternatives. You ca...

If the error occurs only rarely, you can adjust the max_errors setting the CmaOptimizer: https://scone.software/doku.php?id=ref:cma_optimizer This will allow the optimization to continue in the case of errors. Use negative numbers if you want to specify the minimum number of successful evaluations (...

Great! While this approach can be useful depending on your purpose, please keep the following in mind: The result from this measure is always positive, i.e. you will get the absolute value of the acceleration; The "symmetric = 1" computes the acceleration for left and right sides. If you want only o...

Unfortunately, you cannot directly access the Dof accelerations in SconePy at this time. You can however quite easily compute the accelerations by taking the dof velocities, subtracting the dof velocities of the previous frame, and dividing by the frame time, e.g.: current_dofs = model.dof_velocity_...

All the examples you mention use the same reflex-based control strategy, which consists of a combination of force, length and velocity reflexes, with a constant excitation. The difference between the examples is that the control parameters are optimized for different objectives, hence the difference...

Yes, this is possible: open a .scone scenario that uses an OpenSim4 model, and go to Tools -> Convert to Hyfydy... This will work only for supported elements, so you might need to manually adjust the .hfd model afterwards. For example, cylindrical wrapping surfaces are not supported in Hyfydy. It sh...

In that case, you can use the same approach as in the backpack example. You would need to apply an external force instead of a moment in your script, based on how far the backpack is from the target position and how fast it is moving. Alternatively, if you're using Hyfydy, you can set the position o...

I see, but what should be causing the backpack to move up and down? Is there a motor in the backpack, or is it due to the motion of the torso?

Can you explain a bit which movement your backpack should perform? There are various ways to control the position, both directly and indirectly, but it depends on your use case which is best. For example, there already is a tutorial on how to maintain balance by controlling a backpack with gyroscope...