Continuous order tracking
Continuous order tracking
(OP)
Does anyone have a reference (still can't type that word first time!) for this, or a method?
I have a stream of crank angle, time and sensor data. I want to track a specific order as the data arrives - don't want to go through all that resampling and FFT malarkey. I should be able to use the crank angle signal to construct the appropriate multiplier for my data, but just can't get quite get my head around doing it in transient. It's the summation bit that's bogging me down. Ok for steady-state, but transient?
I have a stream of crank angle, time and sensor data. I want to track a specific order as the data arrives - don't want to go through all that resampling and FFT malarkey. I should be able to use the crank angle signal to construct the appropriate multiplier for my data, but just can't get quite get my head around doing it in transient. It's the summation bit that's bogging me down. Ok for steady-state, but transient?
- Steve





RE: Continuous order tracking
As to the rest of it, you've managed to confuse me about what you are confused about.
What I'd do is create a fake sampling interval in crank angle, resample the incoming data using interp1 (or is it 2?) to give me crank angle based data and then bandpass that directly.
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Continuous order tracking
re = 2*sum(signal.*cos(order*2*pi*theta))/numpoints;
im = 2*sum(signal.*sin(order*2*pi*theta))/numpoints;
For steady-state speeds, the summations give the real and imag parts of the line at the chosen order, no filters required (assuming of course that signal is cyclic within the period).
Maybe I just need to sample and reset the summation at the end of each cycle?
- Steve
RE: Continuous order tracking
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Continuous order tracking
- Steve
RE: Continuous order tracking
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Continuous order tracking
- Steve