Development of a GPC control strategy for a continuous frying process based on product quality attributes /
The dynamics of a continuous frying process making a snack
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| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1996.
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| Subjects: |
| Summary: | The dynamics of a continuous frying process making a snack product were modeled and a controlled developed to automatically control product quality attributes on-line. The process was modeled using X (erogenous input), ARX (autoregressive with erogenous input), and ARMAX (autoregressive moving average with erogenous input) model structures. For control purposes, a Generalized Predictive Controller (GPC) was used. The X, ARX, and ARMAX models with the lowest Aikaike's Information Criteria (AIC) values were chosen as the best ones to predict the process dynamics. The process was modeled as a MIMO (multiple-input multiple- output) and as a MISO (multiple-input single-output). The inputs were the oil temperature [C], the submerger conveyor speed [%], and the takeout conveyor speed [%]. The outputs, or product quality attributes, were the color b moisture content [% wb]. the oil content [% wb], and the moisture []. The Generalized Predictive Controller developed in this research employs the models mentioned above to calculate future changes in manipulated variables. Physical constraints of the continuous fryer were also imposed to the controller. These restrict the inputs to a certain range regardless of the optimal value. A tracking test was designed using typical industry values. The output setpoints were changed to see how well the inputs tracked the variation. The response time was adequately short. The input variations were within industry standards. The yielded output signals were smooth and showed little or no overshoot for the different setpoint changes. |
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| Item Description: | Vita. "Major subject: Agricultural Engineering". |
| Physical Description: | xvi, 158 leaves : illustrations ; 28 cm. Issued also on microfiche from Lange Micrographics. |
| Bibliography: | Includes bibliographical references. |