Abstract
In this paper, a method for process frequency response identification is proposed, which can identify multiple points on process frequency response from a single relay feedback test. The process input and output transients resulting from a relay feedback cannot be directly converted to the frequency domain to obtain a process frequency response using FFT. A decay exponential is then proposed to modify the process input and output, so that the process frequency response can be identified with the help of FFT. Real-time testing of the method on various processes gives quite accurate process frequency responses, especially in the frequency range [0,ω(c)], which is important for control design and process modelling. The method inherits and extends the advantages of the original relay auto-tuning technique. It can be easily applied to PID auto-tuning and to transfer function modelling.
Original language | English |
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Pages (from-to) | 1293-1302 |
Number of pages | 10 |
Journal | Control Engineering Practice |
Volume | 5 |
Issue number | 9 |
DOIs | |
Publication status | Published - Sept 1997 |
Externally published | Yes |
Keywords
- FFT
- auto-tuning
- frequency responses
- identification
- relay feedback
ASJC Scopus subject areas
- Control and Systems Engineering
- Computer Science Applications
- Electrical and Electronic Engineering
- Applied Mathematics