I am working on a project where we are using a special pickup microphone to record .wav files of the valvetrain of a diesel engine (running). We are analyzing the audio file to identify if the engine has a problem. I have numerous recordings of engines with and without the a problem. My employer is looking for someone who has the expertise to make a plug in or some other system where a .wav file could be loaded and processed and a colormap or spectral analysis is the output. The end user would be able to tell if the engine had a problem by using the .wav analysis application developed by the programmer. I attached a couple .wav files
While I can see and hear the differences between those waveforms, writing software that can analyze engine health from the sound is likely to be very difficult and very costly (thousands of dollars), and without doing a lot of research first, it will not be possible to predict how the health assessment will be.
This sounds like a good area for the use of heuristic learning algorithms but the trouble with that is that accurate results could not be achieved without enough samples for the system to learn what is good and what is bad. Computer AI is much discussed but in some respects its not so different to what in terms of human expertise we call learning from experience.
I suppose the first step would be to subdivide the audio output in synchronization with the engine cycle but I’m not volunteering! Many years ago I was party to some experiments for using oscilloscope based Sun testers on diesels by clamping a pressure sensor around an injector line as an easy way of triggering the time base and there may well be a modern electronic version of this which would provide synchronization of the cycle with the audio signal. After all the samples in a wav file are really just pressure values derived from a transducer at fixed intervals.
Good luck with this interesting idea.
Thanks for your response. I too worked with the diesel clamp on transducers in the 80’s! And yes i can synch this with a scope using the camshaft position sensor signal are you sure your not interested! 