Identification

Higher education teachers: Blažič Sašo, Matko Drago

Subject description

System analysis classification, algorithm division, signal analysis (excitation and disturbance signals), the area of use.

Simple methods:

- Strejc method (based on a step response),

- Åström method with a relay in a closed-loop,

- model adaptation method.

Least squares method, regression method, bias and consistency of estimates.

Dynamical model parameter estimation, model parameterisation, extended least squares method, instrumental variables method, recursive versions of least squares, the adaptation for time varying systems – weighted least squares and exponential forgetting, the influence of unknown steady states, numerical problems.

Identification of non-parametric models (frequency response analysis, Fourier analysis, correlation analysis, spectral analysis).

Identification of unstable models and closed-loop identification, identifiability of parametric and non-parametric models.

Identification with pattern recognition.

Practical aspects of identification, sampling time selection, signal pre-processing, model choice, the test of model validity and its structure, the issue of time delays, robustness, the choice of an appropriate method.

Objectives and competences:

• To present the area of system identification, especially in relation to dynamical systems.
• To present the least squares method and show its applicability in different areas.
• To show the applicability of parameter estimation methods for dynamical systems.
• To present the methods of non-parametric model identification.
• To expose the problems of identification of unstable systems and the problems of identifiability in a closed loop.
• To introduce the practical problems of identification.

Intended learning outcomes:

• Knowledge and understanding
• Deeper understanding of dynamical system identification

Learning and teaching methods:

• Lectures and laboratory work

Study materials

1. Drago Matko, Identifikacije, Univerza v Ljubljani, Fakulteta za elektrotehniko, 1998.
2. Juš Kocijan, Praktikum identifikacij dinamičnih sistemov, Univerza v Ljubljani, Fakulteta za elektrotehniko, 1998.
3. Sašo Blažič, Identifikacije, Zbirka rešenih nalog, Univerza v Ljubljani, Fakulteta za elektrotehniko, 2007.
4. Torsten Söderström, Petre Stoica, System identification, Prentice Hall 1994
5. Lennard Ljung, System identification, Prentice Hall 1999.
6. Rolf Isermann, Identifikation dynamischer Systeme 1, 2, Springer 1992.
7. Karl Johan Aström. Tore Hägglund: PID Controllers: Theory, Design and
8. Tuning. 2nd Edition. Research Triangle Park, NC: Instrument Societyof America 1995.