Constant Rad/s to Revoluate Joint in Simscape multibody

ı done full parametric crank mechanism by using vectors and I want to create a fixed signal and connect with revoluate from the RAD/S unit but I don't know how to do it

Answer 1

[Pramil]

Hi Enis,

To obtain a constant physical signal like a constant "Rad/s" signal, there are two common ways:

1. Use a "PS Constant" block and in its dialog box, select unit as "rad/s".
2. Use a "Constant" block along with a "Simulink-PS" block and in it's dialog box select unit as "rad/s".

Here is the link to "PS Constant" block and "Simulink-PS" block for your reference:

https://www.mathworks.com/help/simscape/ref/simulinkpsconverter.html

https://www.mathworks.com/help/simscape/ref/psconstant.html

Hope it helps.

[Enis]

I created a connection like this to provide fixed angular and changed all units to rad/s. Then I set the joint tork=automatically computed

and motion=provided input and I did not get any error, the approach seems to be correct.

[Pramil]

If the above configuration is what you want, the better way would be to make the setup like this:

[Enis]

I made the connection as above but

ı got that error;

Invalid unit specified by converter block 'untitled1/Simulink-PS Converter'.

Caused by:

Cannot convert 'rad/s' to 'rad'. Unit expressions are not commensurate.

Stack trace

Component:Simulink | Category:Model error