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Ho, D., Hendeby, G. & Enqvist, M. (2020). A sensor-to-sensor model-based change detection approach for quadcopters. In: Proceedings of the 21st IFAC World Congress, 2020: . Paper presented at IFAC World Congress 2020, July 11-17, Germany (pp. 712-717). Elsevier, 53, Article ID 2.
Öppna denna publikation i ny flik eller fönster >>A sensor-to-sensor model-based change detection approach for quadcopters
2020 (Engelska)Ingår i: Proceedings of the 21st IFAC World Congress, 2020, Elsevier, 2020, Vol. 53, s. 712-717, artikel-id 2Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

This paper addresses the problem of change detection for a quadcopter in the presence ofwind disturbances. Different aspects of the quadcopter dynamics and various flight conditions have beeninvestigated. First, the wind is modeled using the Dryden wind model as a sum of a low-frequent and aturbulent part. Since the closed-loop control can compensate for system changes and disturbances andthe effect of the wind disturbance is significant, the residuals obtained from a standard simulation modelcan be misleading. Instead, a sensor-to-sensor submodel of the quadcopter is selected to detect a changein the payload using the Instrumental Variables (IV) cost function. It is shown that the mass variationcan be detected using the IV cost function in different flight scenarios.

Ort, förlag, år, upplaga, sidor
Elsevier, 2020
Serie
IFAC PapersOnline
Nyckelord
sensor-to-sensor model, change detection, quadcopter, instrumental variables
Nationell ämneskategori
Elektroteknik och elektronik
Identifikatorer
urn:nbn:se:liu:diva-170123 (URN)10.1016/j.ifacol.2020.12.820 (DOI)000652592500116 ()
Konferens
IFAC World Congress 2020, July 11-17, Germany
Anmärkning

Funding: VINNOVA Competence Center LINK-SIC

Tillgänglig från: 2020-09-29 Skapad: 2020-09-29 Senast uppdaterad: 2021-10-04
Ho, D. & Enqvist, M. (2018). On the equivalence of inverse and forward IV estimators with application to quadcopter modeling. In: 18th IFAC Symposium on System Identification (SYSID), Proceedings: . Paper presented at 18th IFAC Symposium on System Identification (SYSID), Stockholm, Sweden, July 9-11, 2018 (pp. 951-956). Elsevier, 51(15)
Öppna denna publikation i ny flik eller fönster >>On the equivalence of inverse and forward IV estimators with application to quadcopter modeling
2018 (Engelska)Ingår i: 18th IFAC Symposium on System Identification (SYSID), Proceedings, Elsevier, 2018, Vol. 51, nr 15, s. 951-956Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

This paper concerns the estimation of a dynamic model from two measured signals when it is not clear which signal should be used as input to the model. In this case, both a forward and an inverse model can be estimated. Here, a basic instrumental variable approach is used and it is shown that the forward and inverse model estimators give identical parameter estimates provided that corresponding model structures have been used. Furthermore, it is shown that this scenario occurs when properties of a quadcopter are estimated from accelerometer and gyro signals and, hence, that it does not matter which signal is used as input.

Ort, förlag, år, upplaga, sidor
Elsevier, 2018
Serie
IFAC papers online
Nationell ämneskategori
Teknik och teknologier Reglerteknik
Identifikatorer
urn:nbn:se:liu:diva-152269 (URN)10.1016/j.ifacol.2018.09.071 (DOI)000446599200161 ()
Konferens
18th IFAC Symposium on System Identification (SYSID), Stockholm, Sweden, July 9-11, 2018
Anmärkning

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 642153.

Tillgänglig från: 2018-10-24 Skapad: 2018-10-24 Senast uppdaterad: 2018-10-30Bibliografiskt granskad
Ho, D. (2018). Some results on closed-loop identification of quadcopters. (Licentiate dissertation). Linköping: Linköping University Electronic Press
Öppna denna publikation i ny flik eller fönster >>Some results on closed-loop identification of quadcopters
2018 (Engelska)Licentiatavhandling, monografi (Övrigt vetenskapligt)
Abstract [en]

In recent years, the quadcopter has become a popular platform both in research activities and in industrial development. Its success is due to its increased performance and capabilities, where modeling and control synthesis play essential roles. These techniques have been used for stabilizing the quadcopter in different flight conditions such as hovering and climbing. The performance of the control system depends on parameters of the quadcopter which are often unknown and need to be estimated. The common approach to determine such parameters is to rely on accurate measurements from external sources, i.e., a motion capture system. In this work, only measurements from low-cost onboard sensors are used. This approach and the fact that the measurements are collected in closed-loop present additional challenges.

First, a general overview of the quadcopter is given and a detailed dynamic model is presented, taking into account intricate aerodynamic phenomena. By projecting this model onto the vertical axis, a nonlinear vertical submodel of the quadcopter is obtained. The Instrumental Variable (IV) method is used to estimate the parameters of the submodel using real data. The result shows that adding an extra term in the thrust equation is essential.

In a second contribution, a sensor-to-sensor estimation problem is studied, where only measurements from an onboard Inertial Measurement Unit (IMU) are used. The roll submodel is derived by linearizing the general model of the quadcopter along its main frame. A comparison is carried out based on simulated and experimental data. It shows that the IV method provides accurate estimates of the parameters of the roll submodel whereas some other common approaches are not able to do this.

In a sensor-to-sensor modeling approach, it is sometimes not obvious which signals to select as input and output. In this case, several common methods give different results when estimating the forward and inverse models. However, it is shown that the IV method will give identical results when estimating the forward and inverse models of a single-input single-output (SISO) system using finite data. Furthermore, this result is illustrated experimentally when the goal is to determine the center of gravity of a quadcopter.

Ort, förlag, år, upplaga, sidor
Linköping: Linköping University Electronic Press, 2018. s. 98
Serie
Linköping Studies in Science and Technology. Licentiate Thesis, ISSN 0280-7971 ; 1826
Nationell ämneskategori
Teknik och teknologier Reglerteknik
Identifikatorer
urn:nbn:se:liu:diva-152701 (URN)10.3384/lic.diva-152701 (DOI)9789176851661 (ISBN)
Presentation
2018-11-30, Ada Lovelace, B-huset, Campus Valla, Linköping, 10:15 (Engelska)
Opponent
Handledare
Forskningsfinansiär
EU, Horisont 2020
Anmärkning

This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 642153.

Tillgänglig från: 2018-11-21 Skapad: 2018-11-15 Senast uppdaterad: 2019-10-12Bibliografiskt granskad
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