Nonlinear and Intelligent Control of a Class of Uncertain Systems with Unknown Disturbance Sources
| dc.contributor.advisor | Behjat, Laleh | |
| dc.contributor.advisor | Sun, Qiao | |
| dc.contributor.author | Bagheri, Pedram | |
| dc.contributor.committeemember | Dimitrov, Vassil | |
| dc.contributor.committeemember | Pieper, Jeffrey | |
| dc.contributor.committeemember | Westwick, David | |
| dc.contributor.committeemember | Shi, Yang | |
| dc.date | 2022-02 | |
| dc.date.accessioned | 2022-01-19T18:06:26Z | |
| dc.date.available | 2022-01-19T18:06:26Z | |
| dc.date.issued | 2022-01 | |
| dc.description.abstract | The existence of phenomena such as uncertainties, unknown disturbance sources, input saturation, and non-affine inputs makes an interesting and yet challenging control problem. Taking a nonlinear approach to such problems compounds the complexities as superposition cannot be utilized. One cannot address each of the aforementioned phenomena in isolation and prove stability in combination. This thesis aims to develop novel nonlinear controllers for a class of uncertain and non-affine systems with unknown disturbance sources. To apply the control methods developed in this thesis to a real-world system, variable-speed variable-pitch wind turbines are used in the majority of this thesis. The reason is the complexity of their dynamics such as uncertainties, unknown disturbance source, and non-affine inputs, which make them a perfect candidate for a nonlinear control design leading to performance with higher efficiency. In doing so, in the first chapter of this thesis, an introduction to the current control problem is presented; the second chapter discusses the existing methods in the literature along with existing gaps for improvements. The continuation of this thesis is paper-based composed of four publications where each addresses a complexity associated with the control of nonlinear systems. In Paper 1, a combination of adaptive and Nussbaum-type-function-based controllers is proposed to tackle uncertainties and disturbance sources as well as the non-affine dynamics. Paper 2 builds upon what is developed in Paper 1 and tackles some of the inadequacies; more specifically, the proposed adaptive laws developed in Paper 1 are made more robust. In addition, asymptotic stability is achieved in both torque and pitch phases. In Paper 3, input saturation is added to the existing unfavorable phenomena such as uncertainties, unknown disturbance sources, and non-affine dynamics. In paper 4, as alluded earlier, although wind turbines are used in the previous chapters, the proposed approaches in this thesis can be applied to a wide range of nonlinear systems with uncertainties and unknown disturbance sources. Hence, to showcase this, the control methodology in this thesis is used to develop a novel way to improve the modeling and control of flexible manipulators. Finally, in the last chapter, a summary of the contributions and suggestions for further research on the current topic are presented. | en_US |
| dc.identifier.citation | Bagheri, P. (2022). Nonlinear and intelligent control of a class of uncertain systems with unknown disturbance sources (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. | en_US |
| dc.identifier.doi | http://dx.doi.org/10.11575/PRISM/39525 | |
| dc.identifier.uri | http://hdl.handle.net/1880/114310 | |
| dc.publisher.faculty | Schulich School of Engineering | en_US |
| dc.publisher.institution | University of Calgary | en |
| dc.rights | University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission. | en_US |
| dc.subject.classification | Artificial Intelligence | en_US |
| dc.title | Nonlinear and Intelligent Control of a Class of Uncertain Systems with Unknown Disturbance Sources | en_US |
| dc.type | doctoral thesis | en_US |
| thesis.degree.discipline | Engineering – Electrical & Computer | en_US |
| thesis.degree.grantor | University of Calgary | en_US |
| thesis.degree.name | Doctor of Philosophy (PhD) | en_US |
| ucalgary.item.requestcopy | true | en_US |