Impact of sensor placement on mode observability and LQG control of a thermoacoustic system

Xiaoling Chen, Hosam Kadry Fathy, Jacqueline O'Connor

Research output: Contribution to journalConference articlepeer-review

2 Scopus citations


This paper investigates the effect of sensor placement on the observability and LQG control of a thermoacoustic model. This model describes combustion instability in a one-dimensional combustor, called a Rijke tube. The transfer function describing this model is transcendental because of the time delay terms in the heat release dynamics. We apply Padé approximation to achieve a finite-dimensional transfer function and truncate the system by neglecting states with low Hankel singular values. We then analyze the impact of the placement and number of sensors on the observability of each mode of the resulting reduced-order model. Next, we design an LQG controller for suppressing pressure oscillations in the simplified thermoacoustic system. We find that placing sensors near the model's pressure nodes slows down the rate at which LQG control attenuates pressure oscillations, increases the control effort required for this attenuation, and worsens the controller's robustness.

Original languageEnglish (US)
Pages (from-to)4214-4221
Number of pages8
StatePublished - 2020
Event21st IFAC World Congress 2020 - Berlin, Germany
Duration: Jul 12 2020Jul 17 2020

All Science Journal Classification (ASJC) codes

  • Control and Systems Engineering


Dive into the research topics of 'Impact of sensor placement on mode observability and LQG control of a thermoacoustic system'. Together they form a unique fingerprint.

Cite this