Simscape Multibody - Spatial Contact Force Block - Interference Fit modeling

Hello,

I wonder if there is a possibility to model an interference fit, like peg-in-hole application.

As far as I see from "Spatial Contact Force" block examples or Simscape Multibody Contact Forces Library (https://www.mathworks.com/matlabcentral/fileexchange/47417-simscape-multibody-contact-forces-library), it is not possible to model this type of contact.

What I need to model is insertation force, friction force and normal forces.

Any help would be appreciated.

Best regards,

Hakan

Answer 1

[Juan Sagarduy]

Hello Hakan

The interference fit is a complex phenomenon to model. I think that I would approach this as a prismatic joint with external friction modelled with pure Simscape.

For that purpose, you need a translational interface linking Multibody and Simscape.

 See link: https://se.mathworks.com/help/physmod/sm/ug/translational-interface-radial-engine-with-gas-force-model.html

Best of Luck Juan

[Hakan Ertugrul]

Hello Juan,

Thank you. Representing the interference fit with prismatic joint is a great idea. I will try.

Actually, I would like to model peg-in-hole robotic manipulator application with interference or close fit. Although your recommendation is more than enough, if you have other recommendations, I will be more than happy to get.

Best regards,

Hakan

Answer 2

[Hakan Ertugrul]

Dear @Juan Sagarduy,

Again, thanks for your answer.

I am using Robotics Toolbox in Simulink and performing dynamical simulation. The simulation consists of a free movement and then a contact arised from a peg-in-hole task.

Because of the contact, I need to pass the reaction forces and moments back to the robot (by multiplying with the transpose of the jacobian of the end-effector of the robot in order to convert them to joint torques) to include contact effects on the robot.

As fas as I see, either Simulink Multibody Contact Forces Libary or Spatial Contact Force Block only gives normal forces in scalar, not vectoral.

Is there a way to get forces and torques in vector format to feed robot for contact dynamics effects?

Thanks in advance.

Best regards,

Hakan