Is it possible to converte ideal angular velocity source signal rad/s to rpm ?

My input signal is in rad/s for ideal angular velocity source but I want to feed my incremental shaft encoder in rpm. Also we don't connect mechanical rotational conserving port via gain or unit conversion block. I didn't find any solution yet

Answer 1

[Fangjun Jiang]

Do the conversion using a Gain block or use this block

https://www.mathworks.com/help/releases/R2019b/simulink/slref/unitconversion.html

[Adeel Ashraf]

Problem is that you can't connect in between mechanical rotational conserving port via gain or unit conversion block.

[Fangjun Jiang]

where is that connection in your diagram?

[Adeel Ashraf]

Now you can see in between these R-R port we can't add gain block or unit conversion

[Fangjun Jiang]

would inserting a pair of "PS-Simulink Converter" and "Simulink-PSConverter" block and a Gain block in between solve the problem?

[Adeel Ashraf]

This is the problem they won't connect with R port.

[Fangjun Jiang]

I don't believe that the conversion is necessary. These are physical "conserving" ports and should be connected directly. Do an experiment, give your control signal "s" a value in rad/s, observe if the encoder gives you matching rpm.

[Adeel Ashraf]

I checked the encoder giving me the result in 'rad/s' but I want the result in 'RPM' for my post processing.

[Fangjun Jiang]

Is the result correct? If your control signal "s" is given a value of 2*pi*10 rad/s, does the encoder give a value of 10 or 2*pi*10 (or whatever value based on its settings)? If it gives a value that corresponds to 2*pi*10 rad/s or 10 rpm, it means it is correct. You just need to convert the unit of the output of the encoder.

[Adeel Ashraf]

I gave my control siganl a constant value of '20' and ideal angular velocity assume it 20 rad/s so when I check the encoder signal and do the conversion period => frequency => rad/s so answer is same in rad/s.

How we suppose to convert the unit of the output of the encoder?

Also I'm attaching the .slx file kinldy check it once.

Thanks

[Fangjun Jiang]

In your model, set the constant to be 2*pi rad/s, that is 1 rev per second. Change the encoder setting to be 10 pulses per rev, run simulation for 1 seconds (that means it turned one rev). Connect a Scope block to the Simulink "Outport" 3 and "Outport" 1.

"Outport" 3 is the "A" output of the encoder, it shows 10 pulses. It is correct.

"Outport" 1 is the "Z" output of the encoder, it shows 1 pulse. It is also correct.

So the model is correct as desired. To measure the output of the encoder, you need to count the pulses of "Outport" 3 or "Outport" 1. That is the same as in physical world that you need to count the pulse output of the encoder. 10 pulses per second on "Outport" 3 means 1 rev per second based on the setting. Then you can convert your processed output to rad/s or rpm.

Keep in mind that in physical world, the physical device just rotates, it does not carry a unit. You observe it and quatify it with a unit.

[Adeel Ashraf]

I got your point the point thank you so much.