Simscape Multibody: Noise in Acceleration Measurement of Transform Sensor

Hey All,

in my Simscape Multibody Model i use transform sensors. The accelaeration mesurements of them are really noisy, the position measurements also have vibrations but not as bad.

I tried different solvers and also ajusted the max step size but both unfortunately didn´t work.

I know that if you calculate a derivative of a somewhat noisy signal the noise power is increased.

So my question is: Is there any setting or anything i can do to get a smooth accelertion signal in Simscape Multibody? Or is the only solution to filter the noisy signals?

Thanks in advance.

Best Regards

Nicholas

[Yifeng Tang]

Any chance that the noise is "real" in the model? Things like hardstop and springs can introduce vibrations and the acceleration signal tends to be noisy when there is vibration. Or maybe the springs needs to be part of the model but dampers are neglected so the vibration will never die out. Similarly if you have hydraulic cylinders but nearly no flow resistance. Just something to look into.

Answer 1

[Steve Miller]

The "noise" is either part of the dynamics of your system or it is "numerical", meaning the solver is not reaching a converged result. If you use a variable step solver and shrink the maximum step size by many factors of 10 and are still seeing noisy signals, then it is part of your model.

If you post your model, we can take a look.

--Steve

[Ben Navon]

@Steve Miller

If I understand correctly, the Simscape Multibody Transform Sensor block is an ideal sensor.

Does block report the true kinematic state (position, velocity, and orientation) without any measurement noise, sensor lag or time delay?