The chapter addresses methods to identify a model for a plant from its time response, from its frequency response, or from the phase of its frequency response. This latter option is particularly important for the design of Crone controllers (which are the subject of Chapters 6 and 15), and is developed, for this reason, so as to find models given by integer, discrete-time or fractional transfer functions, while the two former possibilities are developed for models given by fractional transfer functions only: the way of finding integer and discrete-time transfer functions from such data is well known.
Chapter Contents:
- 5.1 Identification from a time response
- 5.1.1 Known commensurability order
- 5.1.2 Non-commensurable model
- [5.1.3 Filtering, 5.1.3 Filtering]
- 5.1.4 Order optimisation
- 5.2 Identification from a frequency response
- 5.2.1 Levy's method
- 5.2.2 Levy's method, first formulation
- 5.2.3 Levy's method, second formulation
- 5.2.4 Making use of data from many frequencies
- 5.2.5 Levy's method: summing matrixes
- 5.2.6 Levy's method: stacking matrixes
- 5.2.7 Weighted Levy's method
- 5.2.8 Iterations of Sanathanan and Koerner
- 5.3 Identification from the phase of a frequency response
- 5.3.1 Integer transfer function
- 5.3.2 Discrete-time transfer function without zeros
- 5.3.3 Discrete-time transfer function without poles
- 5.3.4 Fractional transfer function without zeros
- 5.3.5 Fractional transfer function without poles
- 5.3.6 Solving the four cases above
- 5.3.7 Fractional and discrete-time transfer functions with both poles and zeros
- 5.3.8 The effect of noise
- [Further reading, Further reading]
- Appendix to Chapter 5
Inspec keywords:
control system synthesis;
modelling;
frequency response;
transfer functions;
identification
Other keywords:
discrete-time transfer functions;
frequency response;
fractional transfer functions;
fractional identification;
integer transfer functions;
Crone controller design;
time response
Subjects:
Simulation, modelling and identification;
Control system analysis and synthesis methods
