As for saving the data, I would suggest using a "To File" block (under the "Sinks" folder). In the image below, I used a vector concatenate block to form a vector which goes into the "To File" block. You can also use a Mux block as well in this case.
If you use the "To File" block, make sure you have the right "Save Format" selected. You can either save it as an Array (which automatically add the model time as the first row in the data) or a Timeseries object (link to documentation for Time Series Objects )
To differentiate the encoder position to get its velocity, I first assume you are using a fixed-step or discrete model. (If you are not, there are continuous versions of these blocks that you can use). The velocity can be found by modeling the following equation in Simulink:
velocity = (sample(n) - sample(n-1))/Ts
You can perform this a few ways ( Note: items correspond with the picture below):
- Write the equation above using basic Simulink blocks (e.g., Add, Unit Delay, Gain).
- Use a Discrete Derivative Block (under the "Discrete" folder). The input to this block would be the samples coming from the encoder. The output would be your velocity.
- Use a Difference block (from the "Discrete" Folder) followed by a gain block
Hope this helps!
