Masters Theses


Ruixiu. Sui

Date of Award


Degree Type


Degree Name

Master of Science


Biosystems Engineering

Major Professor

L. R. Wilhelm

Committee Members

Fred D. Tompkins, Robert S. Freeland


A microcomputer-based measurement system has been developed for plant morphology measurement. Seven ultrasonic sensors and an ultrasonic ranging module were used to scan the plant row for distance-to-plant measurements at three different vertical positions and the top of plant row. An optical incremental encoder was used as a position sensor to measure the forward travel distance of the instrument. The selected horizontal interval between two sample collections was 31 mm. An interface was designed to connect a single board computer (SBC) with the ultrasonic sensor system for data acquisition. The storage capacity of this measurement system is 7,000 data values. A key pad was interfaced with the SBC to input the operation commands. A liquid crystal display (LCD) unit was used to display all results, including cumulative plant volume, maximum and average plant widths at three vertical positions, and maximum and average plant height. The measurement system was tested both in the laboratory and in the field. The results indicate that the unit can be used to obtain accurate measurements for plant morphology analysis.

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