Course detail

Measurement and Experiment

FSI-ZEM Acad. year: 2019/2020 Winter semester

The course familiarizes students with procedures and principles of technical experiment in work of a mechanical engineer. It defines the basics of the modern methods applied for measuring of mechanical quantities, and explains the structure of the measuring and control chain. The course deals with the analysis of the analog and digital signals in time and frequency domain too. A part of the course is also dedicated to the measurement of kinematic quantities, forces, torques, pressure and noise. The course is divided into the following blocks: acoustic measurements in engineering, fundamentals of experimental modal analysis, monitoring of a machine technical condition and service life tests of mechanical units.

Language of instruction

Czech

Number of ECTS credits

4

Learning outcomes of the course unit

An overview of the contemporary experimental detection possibilities of selected mechanical quantities needed for an assessment of failure-free operation of machines and their parts. They will be provided with fundamental practical knowledge and experience with methods of non-electrical physical quantities measurement. Students gain general knowledge of state-of-art measurement technology and methods of evaluation and interpretation of the experimental results.

Prerequisites

Fundamental knowledge in area of mathematics, numerical mathematics, statistics and probability, physics, mechanics and electrical engineering.

Planned learning activities and teaching methods

The course is taught through lectures explaining the basic principles and theory of the discipline. Teaching is supplemented by practical laboratory work.

Assesment methods and criteria linked to learning outcomes

Course-unit credit is awarded on the following conditions: active participation in the seminars, good results of elaborated laboratory exercises.
Examination: course is finished by the final test during 5th week. In the test, the student has to prove knowledge of basic terms, important principles and their application.

Aims

The aim of the course is to present contemporary methods, experimental instrumentation and computer technology for measurement of physical quantities to the students. Measured physical quantities are usually used as input parameters for mathematical modeling of machines and machine parts. Verification of such models is also possible by comparison of measured and simulated data. The course deals with analysis of the kinematic quantities, forces, moments, pressures and noise and with processing of obtained results by using of CAT/CAME methods (computer aided testing/computer assisted measurement and evaluation).

Specification of controlled education, way of implementation and compensation for absences

Attendance at lectures is recommended; attendance at laboratory practicals is obligatory and checked by the lecturer. One absence can be compensated by attending a seminar with another study group in the same week, or by elaboration of substitute tasks. In case of longer absence, compensation of missed lessons depends on the instructions of course supervisor – special task elaboration.

The study programmes with the given course

Type of course unit

 

Lecture

16 hours, optionally

Teacher / Lecturer

Syllabus

1. Technical experiment.
• Process of the technical problem solution.
• Technical experiment as a source of knowledge.
• Fundamentals of the experiment and measurement methods.
• Measurement chain.
2. Transducers of physical quantities.
• Measurement of the physical quantities, classification of the transducers.
• Technical specifications of the transducers.
• Temperature sensors, non-contact pyrometers.
• Accelerometers and gyroscopes with iMEMS technology.
3. Digital signals and data.
• Classification of the analog and digital signals.
• Digital sampling, sampling theorem, aliasing phenomenon.
• Discrete Fourier transformation, FFT fundamentals.
• Aliasing phenomenon in the frequency domain.
4. Time-domain signal analysis.
• Mean, variance, root mean square.
• Crest factor.
• Trend analysis.
• Digital filtration, synchronous detection.
5. Frequency-domain signal analysis.
• Fourier transformation with resampling.
• Application of multispectrum.
• Order analysis, tracking.
• Cepstral analysis.
6. Sound measurement
• Free field, near field, diffusion field.
• Measured quantities, ISO acoustic weighting filters.
• Noise source identification.
• Mapping of the acoustic fields.
7. CAT/CAME systems.
• Measurement chain.
• Plug-in modules (AD, DA, DIO, Count).
• Global Positioning System.
• Methods of localization, GPS errors.
8. Fundamentals of the experimental modal analysis.
• Signal analysis, mechanical system analysis.
• Mechanical and analytical model.
• Classification of the exciters.
• Methods of the oscillation data analysis.

Laboratory exercise

16 hours, compulsory

Teacher / Lecturer

Syllabus

1. Lab of technical diagnostics – safety of operation, excursion.
2. Lab of technical diagnostics – brief about currently solved projects.
3. Crash test – calculation of crash velocity.
4. Crash test – experimental verification by accelerometer.
5. Transducers of the physical quantities.
6. Calibration of the accelerometers and microphones.
7. Specific instruments – LabVIEW, Dewesoft.
8. Programming of the measuring application with LabVIEW, Dewesoft.
9. Acoustic measuring – test of a free field conditions.
10. Acoustic measuring in a semianechoic chamber.