ChLinkMotorRotationAngle::GetMotorAngleDt2() -> wrong acceleration

[Simone]

Hi,

I have a vary basic system consisting of a rotating body, controlled by an infinite stiffness servo, thus being represented by a ChLinkMotorRotationAngle. Even though I am prescribing a constant angular speed, GetMotorAngleDt2() is returning values significantly different than 0. This is happening for various time steppers (HHT, ...) and linear solvers, except for EULER_IMPLICIT time stepper. I also tried changing the tolerances and time steps with no satisfactory results. Is this a known issue, or am I doing or interpreting something wrong?

Thank you in advance, and best regards,

Simone