Nonlinear differential equations in Chuas circuit - frequency control.
Hi,
I've been following the research on Chuas circuit by this chap: https://chuaosc.wordpress.com and so far I've managed to do implement it in Gen (see attached). However, understanding the math to implement a frequency controller is beyond me. Anyone with an advanced knowledge in dynamics of nonlinear oscillators/nonlinear differential equations who could help implement a means of changing the frequency would be much appreciated.
Thanks,
Hi ! I remember this article, pretty great ! Here's the patch and subpatch I did with freq control + scaling factor if used as a LFO.
gen_chua-circuit abstraction
Test patcher :
Hi .QUASAR,
Thanks for getting back to me this, I've spent some time over lockdown experimenting with the oscillator. My next question is, do you know if there is a way to 'force' the oscillator into particular resonances?
My approach is as follows:
Route the x output of the chua oscillator into a bank of resonant bandpass filters, the summed output is then fedback into the chua oscillator. However, this sends the x value into infinity and it doesn't force oscillations at particular frequencies. Any idea how to go about achieving this? I've uploaded the patch here:
Hey, happy to help and thanks for the patch, sending the Chua output to a Bandpass filter is indeed a way to get a pitch out of the chaos.
=> It reminds me of the approach of this artist who used a Multi Duffing System sent to different bank of BP resonators which sounds great ! Here is the github page :
https://github.com/tommmmudd/guttersynthesis
Otherwise there is the "coupled nonlinear system" approach which work great to get pitches out of chaos, as exemplified by this Faust DSP / Max Msp paper and code. You can use the Faust Code to either get the block diagram and adapt it to gen with the Faust Online Compiler or just generate with the same Faust Online Compiler an msp external :
https://bitbucket.org/no_lem/kuroscillators/src/master/Kuroscillators-audio/faust-gen-files/
Finally there's a great topic in the gen forum on a driven Duffing System which sounds just awesome.
Anyway, tons of inspiration out there to adapt chaotic systems to gen (forgot to mention Van der Pol oscillators which could also be coupled)
Looking forward to exploring more coupled NL systems + resonator banks in gen!