In this thesis, a sliding mode controller employing a new sliding surface for
antilock brake system (ABS) is proposed, its stability is proven formally and its
performance is compared with existing sliding mode controllers. The new sliding
mode controller uses the integral-derivative surface, which includes error, its
derivative and its integral, all at the same time. This and the already existing
derivative surface, which includes error and its derivative only, are named zerothorder
sliding surfaces. Their stability analysis is done using first-order auxiliary
surfaces. Auxiliary surfaces equal the sliding surfaces when derivative of the error
becomes zero. The first-order error surface, which includes only the error, and the
integral surface, which includes error and its integral, were also designed for
comparison. During design, tire brake force response is modelled as an
uncertainty. Controllers are simulated on a road with an abrupt change in road
coefficient of adhesion. Controller parameters used are optimized, which results in
comparable stopping distances while braking on a constant coefficient of adhesion
road. Effect of first order actuator dynamics with varying time constants and
actuator absolute time delay were considered. Reaching and sliding properties of
controllers were also investigated, using results on a constant coefficient of
adhesion road. It is observed that zeroth-order sliding surfaces give smoother
response for both derivative and integral-derivative cases. As the controllers
employing error and derivative surfaces get unstable in the presence of actuator
time delay, the integral-derivative surface, proposed in this study, stands as the
best controller.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12613568/index.pdf |
| Date | 01 August 2011 |
| Creators | Okyay, Ahmet |
| Contributors | Cigeroglu, Ender |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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