Can the stepper motor with stepper driver be used in a Simscape Multibody model?

Hello,

I'm trying to create a simulation model of a feed drive system, based on a test rig I have built of a 2-axis gantry feed drive system.

The mechanical system is created in Simscape Multibody from a CAD model of a the linear guide. The joints are primarily revolute, prismatic,leadscrew or bearing joints which have springs/dampers connected with the multibody interface blocks to represent a lumped mass system.

It shows promising results when I connect it with the "Rotational electromechanical converter" block and works relatively smoothly with some zero crossings.

However the real system is driven by stepper motors and it would be ideal if I could simulate it using the Simscape stepper motor models. But when I try to connect them to the multibody with only a single axis model it takes forever to simulate. Even with a really slow pulse period.

Additionally I can't seem to get the stepper motor model to run faster than ~50 RPM.

Is this simply a limitation between simscape 1D to 3D or can I make this work with certain settings? I'm currently using the ode23t solver.

I'll post some pictures of the system just to give an overview. Since it's based on CAD models I can't provide a file that can be executed easily.

The overall system.

The motor input to the mechanical system.

The electrical part of the system.

The way I implement joints.

Answer 1

[Adeline]

Hi,

Thank you for sharing reference images of the model. I understand you are trying to execute a Simscape Multibody model which includes a stepper motor and its driver.

The motor can be connected to a revolute joint in the multibody model using the “Rotational Multibody Interface” block.

In the shared images I noticed that the simulation mode is set to “Normal”. Slowing the pulse may not necessarily speed up the simulation but it can affect the RPM which depends on the control pulse frequency. Instead, try optimizing the model performance by switching the simulation mode to “Rapid Accelerator”.

For details regarding the speed control of the stepper motor, please refer to the following link:

https://www.mathworks.com/help/sps/ug/stepper-motor-with-control.html

For more understanding about the Rapid Accelerator mode, please refer to the following link:

https://www.mathworks.com/company/newsletters/articles/speed-up-your-simulations-with-rapid-accelerator-mode.html

For more ways to optimize performance, please refer to the frequently viewed topics in the following link:

https://www.mathworks.com/help/simulink/performance.html?s_tid=CRUX_lftnav

Hope this helps with the model simulation.