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ORCID
N/A
Access Type
Open Access Thesis
Document Type
thesis
Degree Program
Mechanical Engineering
Degree Type
Master of Science (M.S.)
Year Degree Awarded
2018
Month Degree Awarded
February
Abstract
This thesis explores the possibility of controller restructuring for improved closed-loop performance of nonlinear plants using a gradient based method of symbolic adaptation- Model Structure Adaptation Method (MSAM). The adaptation method starts with a controller which is a linear controller designed according to the linearized model of the nonlinear plant. This controller is then restructured into a series of nonlinear candidate controllers and adapted iteratively toward a desired closed-loop response. The noted feature of the adaptation method is its ability to quantify structural perturbations to the controllers. This quantification is important in scaling the structural Jacobian that is used in gradient-based adaptation of the candidate controllers. To investigate this, two nonlinear plants with unknown nonlinearities viz., nonlinear valve and nonlinear inverted pendulum are chosen. Furthermore, the properties of restructured controllers obtained for two systems, stability, effect of measurement noise, reachability, scalability and algorithmic issues of MSAM are studied and compared with the starting controller.
DOI
https://doi.org/10.7275/10996429
First Advisor
Kourosh Danai
Second Advisor
Mathew Lackner
Third Advisor
Frank Sup
Recommended Citation
Sahare, Kushal, "Restructuring Controllers to Accommodate Plant Nonlinearities" (2018). Masters Theses. 613.
https://doi.org/10.7275/10996429
https://scholarworks.umass.edu/masters_theses_2/613