vnegnev
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Hello,
I am currently trying to remove a peak in the noise spectrum of a particular control variable. The noise is around 40dB above the noise floor, peaking at ~1 MHz with a width of ~300 kHz. I would like to reduce the noise in this region by ~40 dB; the rest of the noise spectrum is less important so I can tolerate noise peaking elsewhere.
It will be tough to use a conventional feedback controller (eg PID) because the delay of my actuator causes a 2*pi phase shift at around 3 MHz. I don't think I can design a stable conventional controller that sufficiently attenuates my noise, given this constraint.
I was wondering, what other kinds of DSP/control algorithms would people suggest I look into? I have looked into adaptive filtering briefly, but in my case there is no 'information' buried in my noise (i.e. my desired signal is zero, when AC-coupled) so I do not imagine an adaptive filter would converge. To my untrained mind, it seems like my best bet is to use pure feedforward techniques - but the phase shift still limits what I can do.
Any advice is much appreciated.
Vlad
(For those who are curious, I am trying to reduce the intensity noise of a laser beam.)
I am currently trying to remove a peak in the noise spectrum of a particular control variable. The noise is around 40dB above the noise floor, peaking at ~1 MHz with a width of ~300 kHz. I would like to reduce the noise in this region by ~40 dB; the rest of the noise spectrum is less important so I can tolerate noise peaking elsewhere.
It will be tough to use a conventional feedback controller (eg PID) because the delay of my actuator causes a 2*pi phase shift at around 3 MHz. I don't think I can design a stable conventional controller that sufficiently attenuates my noise, given this constraint.
I was wondering, what other kinds of DSP/control algorithms would people suggest I look into? I have looked into adaptive filtering briefly, but in my case there is no 'information' buried in my noise (i.e. my desired signal is zero, when AC-coupled) so I do not imagine an adaptive filter would converge. To my untrained mind, it seems like my best bet is to use pure feedforward techniques - but the phase shift still limits what I can do.
Any advice is much appreciated.
Vlad
(For those who are curious, I am trying to reduce the intensity noise of a laser beam.)