Define gravity in Simmechanics

I have modeled a multibody robot in solidworks and when i import it in simmechanics, it moves in an unexpected direction. i think it is because i considered the gravity in the -z direction in my CAD model, but the default gravity in simmechanics is in -y direction. how can i change the gravity direction and define it in -z direction in simmech? because its very hard to change it in my CAD model.

Answer 1

[Nicolas Schmit]

In Simscape Multibody the gravity is towards the -z axis by default. However, the definition of the axis in Simscape might be different from the axis in your CAD software (like in SolidWorks where the +y axis is upward). If needed, you can change the orientation of the gravity using the Mechanism Configuration block.

[saeed shekari]

Thanks, it worked.

[Bassim Younis]

Hey Nicolas,

Im trying to model an inverted pendulum using simmechanics. I have imported the model from Autodesk Inventor and defined the gravity vector to be along -z (which is along the negative axis of the pendulum link). The equilibrium position (starting position of the pendulum) however has been defined using Inventor to be when the pendulum is aligned with +ve z..hence inverted pendulum.

The problem Im facing is that the pendulum falls towards -ve z-axis although the equilibrium position has been specified already to be +ve z, and there aren't any outside disturbances. Any idea how I can fix that?

Thanks!