70/LM-0088 - AUTOMATIC MEASUREMENT SYSTEMS
Academic Year 2021/2022
Free text for the University
PAOLO ATTILIO PEGORARO (Tit.)
- Teaching style
- Lingua Insegnamento
|[70/83] ELECTRONIC ENGINEERING||[83/00 - Ord. 2018] PERCORSO COMUNE||6||60|
The course “Automatic Measurement Systems” is designed to provide first year students of the “Laurea Magistrale” Degree in Electronic Engineering (Bachelor graduated students) with a deeper understanding of electronic measurement area, with specific attention to digital signal processing of measurement signals and measurement uncertainty evaluation.
The course aims at providing deep knowledge of software tools useful for designing and using automated measurement systems.
In details, the aims can be presented by the following five descriptors:
- Knowledge and understanding
Deep knowledge and understanding of theoretical and applicative topics in the field of automated measurement systems. Knowledge of devices and techniques to design and implement an automated measurement system.
- Applying knowledge and understanding
Ability to design and manage complex automated measurement systems, by choosing measurement techniques that are appropriate from a technical point of view. Ability to integrate advanced measurement techniques with tools aimed at performance analysis.
- Making informed judgements and choices:
Ability to evaluate results, select relevant information and appropriate approximations to design and implement measurement systems. The student must test her/his capability to perform design choices and justify them.
Capability to communicate technical information both orally and in writing. Ability to present and justify design choices. Ability to discuss problems and solutions with specialists and non-specialists. Anility to be either concise or accurate depending on the context.
-Continuous learning skills
Capability of continuous learning, through the proper interpretation of scientific and technical literature, manuals of manufacturers and technical standards.
The prerequisites are those indicated in the regulations of the "Laurea Magistrale in Ingegenria Elettronica" for admission to the first year.
Basic knowledge of electronics and conventional instrumentation for electrical quantities
Knowledge of the fundamental measuring methods and uncertainty evaluation and propagation.
Introduction(3 hours -lessons)
Course presentation (expected skills, examination guidelines, reference materials).
Digital measurement system, components and performance.
Automatic Measurement Systems (4 hours - lessons)
Automatic measurement systems: concepts.
Automatic measurement systems: components and architectures.
Information Quality (5 hours - lessons)
Review of probability and uncertainty theory.
Signal Processing (10 hours – lessons)
Data acquisition and AD/DA conversion: concept overview.
Oversampling and Sigma-Delta converters
Digital processing of measurement signals.
Noise and other interference signals.
Weighted Least Squares.
Sine fit algorithms.
Measurements in the Frequency Domain (18 hours – lessons)
Review on of theory and problems of Fourier Analysis. Discrete Fourier Transform (DFT and FFT)
Aliasing and leakage reduction techniques. Smoothing windows.
Amplitude, phase and frequency measurements for sinusoidal signals. Interpolated DFT.
Digital filters: fundamentals on theory and design.
Virtual instrumentation and automatic measurement systems design – Laboratory (20 hours – laboratory)
The LabVIEW graphic environment.
Development of Virtual Instruments (VIs) and SubVIs for signal processing.
Examples of digital filters implementation.
Laboratory experience for automatic measurement system design and simulation, intended to be faced also by students grouped by 2 to 3.
Data acquisition cards: properties and specifications.
Ph.D students' and/or industry people's lectures.
The course is composed of 40 hours of theory lessons and 20 hours of practice, for a total of 60 hours. During the theory lessons, the teacher sets out the topics in the program; during the practice sessions, students, working in small groups under the supervision of the teacher, learn how to design and implement using the techniques of virtual instrumentation their own solution to an assigned measurement project (for instance, the synchronized measurements of amplitude, phase angle and frequency of a sinusoidal signal with dynamic parameters).
Verification of learning
The examinations are carried out in two stages.
Students have to develop, in a team of up to three people, a project (an example of Automatic Measurement System in LabVIEW environment) on a topic covered during the course. A report on the laboratory activity is required. A discussion on the project and on theoretical issues is also required.
During the lessons (laboratory lessons), the aims of the project, related international standards and regulations, methods and results of validation tests are discussed.
The report, together with the project code, must be sent to the professor before the second stage.
The final exam (second stage) consists in an oral exam aimed at discussing the report and the project outcomes and at verifying the preparation of the student in other topics included in the course.
The final mark to pass the exam ranges from 18/30 to 30/30. The final evaluation considers both the stages and maximum 15 points are for the first one (project discussion is part of the first stage) and maximum 15 points for the second one, which are summed to define the final mark. The evaluation rewards student’s autonomy during project, capability to rethink the theoretical lessons in applications, defend personal choices and strategies in the project, communicate clearly acquired information.
In this regard, the questions of the oral are organized to highlight the following aspects:
- Acquired knowledge of theoretical topics;
- The applied knowledge and understanding, with particular attentio to practical cases;
- The capacity to apply methods and to make judgements on the obtained results, with particular attention to the achieved accuracy of the automatic measurement system designed for the project.
Teaching material provided during the course.
This is the reference material covering all the topics and aspects.
Useful book about digital signal processing of measurement signals:
Gabriele D'Antona, Alessandro Ferrero: Digital Signal Processing for Measurement Systems: Theory And Applications, Springer Verlag, 2006.
Useful book on digital signal processing, DFT, Zeta Transform, digital filters:
A. V. Oppenheim, R. W. Schafer: "Discrete-Time Signal Processing", Pearson, 2009.
or its previous editions or versions.
Other textbooks for supporto and/or deeper learning:
AA. VV.: “Phasor Measurement Units and Wide Area Monitoring Systems”, Eds. C. Muscas, A. Monti, F. Ponci, Academic Press, 2016 (Synchronization methods and amplitude, phase and frequency measurements for sinusoidal signals. Support to the project.)
The teacher provides the slides used for the presentation of lessons in electronic format.
Datasheets of measurement devices and international standards are also presented and discussed.