碩士 / 國立臺灣大學 / 生物產業機電工程學研究所 / 89 / ABSTRACT
The objectives of this study were to develop an automatic system for underwater ultrasonic sorting of potatoes, through the application of LabVIEW, a graphical programming software containing automatic acquisition of ultrasonic signals, calculation of power spectral moments, and building functions for the classifications of potatoes. The output results from running the program was adopted to control the potato sorting mechanism.
In the experiment, fresh potato samples were purchased from fruit market . After measuring weight, volume, density, and other characteristics of the potatoes the samples were placed between a pair of underwater ultrasonic probes and then the LabVIEW program was initiated to acquire the received ultrasonic signals and calculate power spectral moments. Potato was artificially cut through the long axis of it by a driller in order to simulate different levels of porosity in potato flesh criterion.
The results showed that the bigger the potato's density, the greater the power spectral moments is. The correlation between density and power spectral moments was analyzed and a critical value of power spectral moments was chosen for sorting.
The critical value was stored in the program and compared with the measured power spectral moments of each potato. If the measured power spectral moments is greater than the critical value, the potato has small porosity, and vice versa. A sorting mechanism based on this software will achieve the goal of classifying potatoes automatically in underwater ultrasonic system.
Keywords:Potato, Ultrasound, Underwater, Automatic sorting,
Graphical programming，Spectral moments.
| Identifer | oai:union.ndltd.org:TW/089NTU00415016 |
| Date | January 2001 |
| Creators | Chian-Jen Huang, 黃千珍 |
| Contributors | Fu-Ming Lu, 盧福明 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 114 |
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