Fundamental part: Amplitude characterisation, classification of signals, Fourier analysis and Laplace transforms in signal analysis, discrete signals (sampling, averaging, DFT, FFT, correlation methods, signals and linear systems - frequency response functions, power spectral density, frequency analysis with FFT, frequency analysis with filters, Z-transforms and digital filtering.

The students will get practical training in using the theoretical concepts and signal analysis methods by computer exercises.

Application part: Control of mechanical systems, machine monitoring, active control of sound and vibration. In the computer exercise in machine monitoring it is shown how vibration measurements can be used to detect defects in bearings. In the laboratory exercise on active control of sound digital filtering is used to attenuate sound in a duct.

The aim of the first part of the course is to give the students knowledge about the theoretical foundations of signal analysis, and ability to apply this knowledge for analysis of mechanical systems. The aim of the application part of the course is to acquire knowledge and practical ability in important methods in analysis of mechanical systems.

The student should after finishing the course be able to:

• Use a signal analyser (FFT-analyser) and be able to choose the measurement setup: frequency range, length of time record, time windows, number of averages etc.
• Perform signal analysis on measured time record in Matlab.
• Choose appropriate signal analysis methodology for a given problem. For example choosing between time or frequency domain analysis, one-channel or multi-channel analysis, different types of filtering etc.
• Interpret results from different types of signal analysis, for instance spectra, correlation functions or frequency response functions.
• Be able to extract information about the character of the studied signal such as periodicity, time delays and linearity.

Lectures and self-study

Five lectures overview the theoretical and practical aspects of signal analysis, such as Fourier analysis, FFT, time-frequency analysis, correlation, signals and linear systems, and Z-transforms and digital filters. Each lecture is 2 x 45 minutes long and starts with the academic quarter (HH:15). There is an optional preparatory quiz assessing the students' knowledge before each lecture. The lectures are meant to complement self-study with video snippets in Canvas, which cover the topics in the course book in more detail. The lectures are also meant as opportunities for deeper discussions from the self-study and the quizzes. The fifth lecture is optional and covers real-world applications in academia and industry, highlighting the trends, challenges, and opportunities of signal analysis in the prevailing AI era. 

Home assignments

Four mandatory Matlab-based home assignments are part of the course. For each assignment, there will be an optional tutorial and a mandatory seminar (see below). The assignments will be reported following the template on Canvas, where they must be submitted latest by the time of the seminar. Two students are permitted to cooperate and submit a joint report. Both persons in the group must do the work together, and each student will be examined that they know and understand the assignments during the seminars. This course part has two credits (HP) and is denoted LAB1 in Ladok. 

• Tutorials (optional): A few days before the seminar, there will be four 2-hour computer tutorials (datorövningar), during which you can get support from the TA to solve the home assignments. 
• Seminars (compulsory): Each seminar is 45 minutes long and involves your participation in reviewing and discussing your report and that of the other groups. Around 4-6 pairs of students typically attend each seminar. You can sign up for a seminar on Canvas. The lists can be found under People/Groups/

OBS: The seminar time you sign up for will become the deadline for your assignment. 

Laboratory assignment 

The laboratory assignment is a hands-on opportunity to apply your knowledge in practice. The assignment consists of devising an active noise control system. This course part has one credit (HP) and is denoted LAB2 in Ladok.

• When: The lab lasts up to four hours and starts with the academic quarter (HH:15), but make sure to be at least 5 minutes earlier. You can sign up for one of the lab times offered on Canvas. The lists can be found under People/Groups/. 
• Where: MWL lab on the ground floor of Teknikringen 8 (see Map). The TA will meet you at the entrance on the Vehicle Engineering Lab side (and not on the Munin/Hugin side). 

SD1120 Sound and Vibration 9.0 credits

Main course book

Bodén, H. Ahlin, K., Carlsson, U., Applied Signal Analysis, SD2125 Signals and Mechanical Systems, KTH Royal Institute of Technology, 2018. 

The course book is available as a PDF on Canvas. 

Online learning material

Handouts for each of the chapter sections covered in the Applied Signal Analysis book are also available as PDFs on Canvas. Supplementary online material includes short video snippets on Canvas covering the topics in the handouts. 

Instructions and old exams

Instructions for the home assignments, lab assignment, and examples of old written tests and exams are on Canvas.

A personal computer

Matlab

Students at KTH with a permanent disability can get support during studies from Funka:

Funka - compensatory support for students with disabilities

A, B, C, D, E, FX, F

• LAB1 - Laboratory Works, 2.0 credits, Grading scale: P, F
• LAB2 - Laboratory Works, 1.0 credits, Grading scale: P, F
• TEN1 - Control Test, 3.0 credits, Grading scale: A, B, C, D, E, FX, F

Based on recommendation from KTH’s coordinator for disabilities, the examiner will decide how to adapt an examination for students with documented disability.

The examiner may apply another examination format when re-examining individual students.

Written examination (TEN1; 3 university credits). Computer exercises (LAB1; 2 university credits), Laboratory exercise (LAB2; 1 university credits).

The requirements for a passing grade are:

• One passed laboratory exercise (LAB1).
• Four passed home assignment reports, plus attending four seminars (LAB2).
• Enough scores on two written tests or final exam (TEN1). 

The grade will be set using the results of the written tests. The maximum number of points on each written test is 15. Completing preparatory quizzes gives up to 1 bonus point per written test. To get a passing grade (E), you must get at least 6 points on each written test. Additionally, the following requirements apply to the total result from both tests:

The exam in January is not mandatory if you obtain a sufficient score on the two written tests in the Autumn. It is also possible to take part in the examination corresponding to written test 1 or 2 at the final exam. If you re-take one of the written tests at the exam, the best result is kept. This course part is denoted TEN1 in Ladok and has three credits (HP).

In the case of grade Fx, it is possible to get an E by handing in a correct solution to an extra homework assignment.

• All members of a group are responsible for the group's work.
• In any assessment, every student shall honestly disclose any help received and sources used.
• In an oral assessment, every student shall be able to present and answer questions about the entire assignment and solution.