Simscape - Combine Harmonic Drive Driveline and Multibody

Hi,

using Simscape Multibody to Simulate a Harmonic Drive I tried to combine the Harmonic Drive Module "Simscape / Driveline / Gears / Harmonic Drive" with Multibody elements like the Revolute Joint and Solids.

My aim is to combine these module in a way that I can input and/or measure at each revolute joint:

• Torque/Speed of the Wavegenerator (B)
• Torque/Speed of the Flex Spline (F)
• Torque/Speed of the Circular Spline (C)

... and combine transfer this energy/motion to other Multibody Elements.

My problem is that I am used to Multibody and Driveline which I never used before is quite different.

If my understanding is correct this should be possible by using the elements below and maybe some other. However, I don't really know how to combine them properly. For example: 3 Revolute Joints connected to the World Frame and each Harmonic Drive Part. The Revolute Joints are then connected to the Driveline Elements with input/output torque/speed. One of the will have to get an external Speed/Torque input as Reference.

Can someone explain to me if/how this could be done?

I know there will be 3 or more possible outcomes. One of them would really help me to understand, how this works. Thank you!

Answer 1

[Kothuri]

Hi Jannik,

To integrate the “Harmonic Drive” block from Simscape Driveline with Simscape Multibody joints and solids, you can follow the below steps:

• The Harmonic Drive block has three connection ports: “Wave Generator (B)”, “Flex Spline (F)” and “Circular Spline (C)”. These represent the three main rotating parts of the harmonic drive.
• Revolute Joints in Simscape Multibody can represent the rotational motion of rigid bodies. You can use them to model the rotation of the Wave Generator, Flex Spline, and Circular Spline.
• You can use the “Rotational Multibody Interface” to bridge between Simscape Driveline rotational ports and Simscape Multibody rotational joints.
• Connect the “B”, “F” and “C” ports of the Harmonic Drive each to a Rotational Multibody Interface.
• Connect these interfaces to the corresponding Revolute Joints in your Multibody model that represents the rotation of the wave generator, flex spline and circular spline in the Multibody model.
• To measure torque or speed at any joint, use the Ideal Torque Sensor or Ideal Rotational Motion Sensor connected between the Rotational Multibody Interface and the corresponding joint.
• To input torque or speed, use the Ideal Torque Source or Rotational Motion Source.
• Ensure all connected joints have a common mechanical reference point.
• Use the “Mechanical Rotational Reference” to ground the driveline connections properly.