A PLC-based control system associated with ultrasonic sensors and an electro-gyro allows an implementation for the direction-speed control of an automatic vehicle in field
| Autor: | Kuo-Hao Wu, 吳國豪 |
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| Rok vydání: | 2010 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 98 The purpose of this thesis was to develop a programmable logical controller (PLC)-based control system associated with an electro-gyro and two ultrasonic sensors to allow an implementation for the direction-speed control of an automatic vehicle in a multi-row crop environment. By connecting an analog to digital converter (ADC) to a PLC, analog signals of sensors could be digitalized into the virtual comparators of a PLC to form multiple logical outputs as the input logical variables. In accordance with the functions of input logical variables to group into straight and turning programs, the Boolean algebra algorithm was employed to deduce the complex logical issues existing in the direction-speed control of an automatic vehicle to obtain the Boolean relations between input and output logical variables of the PLC. The virtual relays of the PLC were used to connect each group program to construct a complete control system. While the vehicle moves along plant row banks in the field, two ultrasonic transducers equipped in the vehicle could sense the distance between two-side banks as the floating computations to instruct the direction-speed control system to create a middle traveling path for regulating motional direction of the vehicle. By integrating the angular velocity determined by an electro-gyro, the turning angles of the automatic vehicle could be calculated as an indication to command the turning motion at the headland. The experimental results showed that the automatic vehicle could smoothly move in the straight path, where the path width was between 70cm and 100cm, and precisely operate the turning motion at the headland. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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