Martin Enqvist: Research

At the moment, Martin Enqvist is mainly working within the Vinnova Industry Excellence Center LINK-SIC, where he is area coordinator for the aerial vehicles and marine vessels research projects, within the EU project MarineUAS, and in a CENIIT project about Adaptive linearization of electronic devices, where he is project leader. Previously, he has worked in projects funded by the Swedish Research Council and by the Flemish and Belgian governments.

Martin Enqvist's main research interests concern system identification, i.e., data-based modeling of dynamical systems based on measurements of their input and output signals. This is an important topic within the research field of automatic control since most modern control-design methods are model-based. Actually, control-oriented modeling of an unknown system can be much more time-consuming and challenging than the actual control design in many cases.

Some of the research topics that Martin Enqvist has worked on or is investigating right now are:

• Approximation issues in system identification (e.g., linear approximations of nonlinear systems, estimation based on incomplete statistical information)
• Nonlinear system identification (e.g., block-oriented systems, nonparametric models, nonlinearity detection)
• System identification in closed-loop and network settings
• Dimension reduction
• Estimation of inverse models
• Unknown input problems
• Applications: aircraft/rotorcraft, cars, ships, electronic amplifiers

Supervision of PhD students

At the moment, Martin Enqvist is supervising the following PhD students:

• Fredrik Ljungberg: Research topic: Ship modelling for estimation and control (Martin Enqvist main supervisor since Sep. 2017).
• Du Ho: Research topic: UAV modeling and diagnosis (Martin Enqvist main supervisor since Oct. 2015).
• Roger Larsson (Industrial PhD student): Research topic: Aircraft system identification (Martin Enqvist main supervisor since Apr. 2012, co-supervisor Sept. 2007 - Apr. 2012).

Previously, Martin Enqvist has been supervisor for:

• Ylva Jung (Martin Enqvist main supervisor Apr. 2012 - Jan. 2019, co-supervisor Jan. 2010 - Apr. 2012)
• Jonas Linder (Martin Enqvist main supervisor Oct. 2012 - Mar. 2017).
• Christian Lyzell (Martin Enqvist main supervisor Apr. - Nov. 2012, co-supervisor Mar. 2008 - Apr. 2012).

PhD theses

[PhD3]:

Y. Jung. Inverse System Identification with Applications in Predistortion. PhD thesis, Linköping University, Linköping, Sweden, 2019.

[PhD2]:

J. Linder. Indirect System Identification for Unknown Input Problems: With Applications to Ships. PhD thesis, Linköping University, Linköping, Sweden, 2017.

[PhD1]:

C. Lyzell. Structural Reformulations in System Identification. PhD thesis, Linköping University, Linköping, Sweden, 2012.

Licentiate's theses

[Lic5]:

D. Ho. Some Results on Closed-loop Identification of Quadcopters. Licentiate's thesis no. 1826, Department of Electrical Engineering, Linköping University, Linköping, Sweden, 2018.

[Lic4]:

J. Linder. Graybox Modelling of Ships Using Indirect Input Measurements. Licentiate's thesis no. 1681, Department of Electrical Engineering, Linköping University, Linköping, Sweden, 2014.

[Lic3]:

Y. Jung. Estimation of Inverse Models Applied to Power Amplifier Predistortion. Licentiate's thesis no. 1605, Department of Electrical Engineering, Linköping University, Linköping, Sweden, 2013.

[Lic2]:

R. Larsson. System Identification of Flight Mechanical Characteristics. Licentiate's thesis no. 1599, Department of Electrical Engineering, Linköping University, Linköping, Sweden, 2013.

[Lic1]:

C. Lyzell. Initialization Methods for System Identification. Licentiate's thesis no. 1426, Department of Electrical Engineering, Linköping University, Linköping, Sweden, 2009.

Editorial work

Furthermore, Martin Enqvist is also Associate Editor for Automatica (since December 2008) and IEEE Control Systems Letters (since January 2017) and a frequent reviewer of papers that have been submitted to scientific journals and conferences.