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beagleboard / librobotcontrol

Robotics Focused library for embedded Linux computers. Mirror of https://git.beagleboard.org/beagleboard/librobotcontrol
https://beagleboard.org/librobotcontrol
MIT License
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Bring back the manual about discrete time SISO filters #147

Closed d01010101 closed 5 years ago

d01010101 commented 5 years ago

Searching for this does not give much but specialized literature and the manual from StrawsonDesign. Yet you use these in MIP sources. Would it be possible to bring the manual back?

StrawsonDesign commented 5 years ago

I don't follow. The only manual I wrote on the topic is the primary documentation here

http://strawsondesign.com/docs/librobotcontrol/group___s_i_s_o___filter.html

d01010101 commented 5 years ago

Yes, it is preliminary, and I hoped for some continuation. Google shows this:

www.strawsondesign.com/content/manual-discrete-siso Discrete-Time SISO Filters In this modern age of low cost microcontrollers its is now the norm to control continuous time dynamic systems with ...

but in reality this page does not exist. Of course you can find generic manuals like https://www.ethz.ch/content/dam/ethz/special-interest/mavt/dynamic-systems-n-control/idsc-dam/Lectures/Digital-Control-Systems/Slides_DigReg_2013.pdf but I thought that you have something more specific to the library, usage of buffers etc.

If it never existed, I will just try to use the API docs.

StrawsonDesign commented 5 years ago

Ah yes, I remeber that page now, thats was 3-4 years ago and was very brief. The new doxygen docs are many times more detailed.

I highly suggest Thomas Bewley's book, Numerical Renaissance, for learning about SISO filters. It's available as a free PDF at http://numerical-renaissance.com/

d01010101 commented 5 years ago

I browsed the API and indeed it looks like canonical filters, where history size is determined by filter type, not much to tinker.

StrawsonDesign commented 5 years ago

Correct, although if you want more history you can use rc_ringbuf_alloc to allocate more space in the rc_filter_t struct input/output buffers without affecting filter behaviour.

StrawsonDesign commented 5 years ago

What would you want to tinker with? Perhaps there is an easy feature I could add.

d01010101 commented 5 years ago

I would not want to tinker, it is the advantage of these filters that they work out of the box. When I initially read something about handling buffers, I was afraid that I need to tinker more than normally with filters like that and I asked about docs. It is a good set of classic filters, which has all the features I want.