How to model a DC motor hoist with Simscape Multibody?

I am new to Simscape. I want to model and simulate a simple hoist driven by a DC motor.

A rod is fixed to the wall at one end. Its other end is mounted with a DC motor, and the motor drives a rope spool to lift the load. See the figure.

But I have totally no idea how to connect the DC motor block (from Simscape/Electrical/Electromechanical/Brushed Motors) with the Belt-Cable Spool block (from Simscape/Multibody/Belts and Cables). I don't know how to drive the spool to spin with the DC motor. Any suggestions?

Answer 1

[SYED IMTIAZ ALI SHAH]

Hi, you can use 'Belt-Cable Spool' in Simscape Multibody. The belt cable spool rotates about an axis, you can then attach a DC Motor with it, through 'Rotational Simscape Multibody' found in 'Simscape Multibody Multiphysics Library'.

This my not be much helpful, however now you know where to start from.

[SYED IMTIAZ ALI SHAH]

I have attached the slx file, if you still haven't found any answer, I can help you with a tutorial.

[Weixian Zhang]

Thanks for your answer, but your model does not run in my MATLAB R2019b. I have built a model with Belt-Cable Spool element, see the attached file. In case you cannot open model created in R2019b, here is a screenshot.

But the simulation is incorrect. The load block just flies in disorder. What's possibly wrong with my model?

[SYED IMTIAZ ALI SHAH]

Can you save your file in 2018b version by going to file>export as>previous version>2018b?

[Weixian Zhang]

Here is the R2018b slx file.

[Maadhav Akula]

Assuming that you used Fixed-Step Solver, what exactly do you mean by, 'The load block just flies in disorder.'

[SYED IMTIAZ ALI SHAH]

I looked into your .slx file. The motor and voltage sources were not there (Probably due to conversion from 2019b to 2018b) so I don't know what parameters values you had chosen. I replaced the block you used (Ideal Torque Sensor, and other two, attached to DC motor) with just one block Rotational Simscape Interface (found in Simscape Multibody Multiphysics Library, you need to install it form adon)

Instead of using fixed voltage source, I used controlled voltage source, your can play with the power of your motor and voltage to keep the mass at certain upward velocity. I used PID, due to lack of time I could not perfectly tune it, however it can easily be done.

attached it the 2018b slx file, I hope you can run it with 2019a/b.

[Weixian Zhang]

I'll explain what "fly in disorder" means...

Acutally I'm trying to simulate 4 motors lifting a load. This "fly in disorder" problem happens to the 1-motor model sometimes, but it happens to the 4-motor model more frequently.