The course aims to provide a detailed view of measurement techniques of mechanical and thermal variables and to make students able to carry out correctly the digital acquisition of data related to mechanical systems, the pre-processing of the signals and identification and the diagnostics of the main parameters of these systems. If this course is compared to basic courses about measurements, it results to be more focused on signal analysis and signal processing tools in the time and frequency domains (frequency response function, coherence function, Hilbert transform, cepstrum, time-frequency transform, zoom-FFT) are provided to the students. Furthermore, analogic/digital conditioning techniques of signals are treated as well.

Description of topics
Signals in the time domain
Classification of signals and their features: analogic and logic signals, stationary and non-stationary signals, random and deterministic signals.
Analysis in the time domain: statistical parameters and correlation
Statistical parameters are introduced since they are fundamental to describe signals in time domain.
Correlation functions
Advanced techniques for data acquisition
The basic concepts about signal acquisition treated in the course “Misure Meccaniche e Termiche” are recalled and deepened. Different acquisition strategies and high-level sampling approaches are explained
The convolution integral and the theorem of convolution
Dirac function, impulse response
The convolution integral and the theorem of convolution
Frequency response function
Signal analysis in the frequency domain
Fourier transform, direct and inverse transform, aliasing, frequency resolution, leakage, windowing techniques.
Characterisation if systems in the frequency domain: spectra, power-spectra, cross-spectra, coherence function, estimation of the frequency response function
Hilbert transform, cepstrum, time-frequency transform

Fieldbus
Data Transmission, digital communication, protocols and buses

Bibliography
[1] J. Bendat and A.G. Piersol: Engineering applications of correlation and spectral analysis, John Wiley and Sons
[2] J. Bendat and A.G. Piersol: Random Data, John Wiley and Sons
[3] G. D’Antona, Alessandro Ferrero: Digital signal processing for Measurement systems, Springer
[4] A. Brandt: Noise and Vibration Analysis, Signal Analysis and Experimental Procedures, Wiley
[5] Kenneth G. McConnel: Vibration Testing, Theory and Practice, John Wiley & Sons, Inc, 1995
[6] A.C. Neve: Introduzione al Digital Signal Processing (DSP), Schonefeld & Ziegler, 2002

The attendance to the lectures is not mandatory.

The exam is composed by a written and an oral part. Alternatively (and only if explicitly mentioned by the teacher), it could be a discussion about activities carried out by the student during the course.