• Journal of Biosystems Engineering
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• v.23 no.1
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• pp.75-82
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• 1998

Autonomous speedsprayer operation was conducted using a fuzzy controller combined with a DGPS. The signal of DGPS receiver and signals of four ultrasonic sensors were processed in real time. The speedsprayer was steered with two levers controlled by two hydraulic cylinders. The fuzzy controller has two inputs; direction of running obtained from the DGPS receiver and distance from trees measured by ultrasonic sensors. The operation times of the hydraulic cylinders were inferred as outputs of the fuzzy controller. Field test results showed that the speedsprayer could be autonomously operated by the developed fuzzy controller including turning operation in the end of the tree row. The ultrasonic sensors contributed a little to performance of the autonomous operation, but the speedsprayer could avoid trees or obstacles in emergent situations with them.

• Journal of Biosystems Engineering
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• v.21 no.2
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• pp.175-181
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• 1996

Autonomous speedsprayer operation was conducted using the developed FLC(Fuzzy Logic Controller). Orchard image and signals of ultrasonic sensors were processed in real time. The speedsprayer was modified to be steered by two hydraulic cylinders. The FLC has two inputs, direction of running and distance from obstacles. The operation time of hydraulic cylinders were inferred as output of the FLC. Field test results showed that the speedsprayer could be autonomously operated by the FLC along with the image processing and the ultrasonic sensors. The ultrasonic sensors didn't contribute to the improvement of guidance performance, but the speedsprayer could avoid trees or obstacles in emergent situations with them.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.648-657
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• 1996

Autonomous speedsprayer operation in an orchard was conducted using a fuzzy logic controller (FLC). Orchard image analysis and signals of ultrasonic sensors were processed in real time. The speedsprayer was modified to be steered by two hydraulic cylinders. The FLC has two inputs of direction of running and distance from obstacles. Operation time of the hydraulic cylinders were inferred as output of the FLC. Field test results showed that the speedsprayer could be autonomously operated by the FLC along with the image processing and the ultrasonic sensors. The ultrasonic sensors didn't contribute to the improvement of guidance performance, but the speedsprayer could avoid trees or obstacles in emergent situations with them.

• Journal of Biosystems Engineering
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• v.21 no.2
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• pp.167-174
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• 1996

A Fuzzy Logic Controller(FLC) was developed for the autonomous operation of speedsprayer in an orchard. The autonomous operation with the FLC was graphically simulated under the real condition of the orchard. Image processing was used to find out the direction of running and four ultrasonic sensors were used to detect obstacles for the running. The simulation results showed that the speedsprayer could be operated autonomously with the FLC combined with the image processing and the ultrasonic sensors.

• Journal of Biosystems Engineering
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• v.22 no.4
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• pp.487-496
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• 1997

A fuzzy logic controller(FLC) was developed for the autonomous travel of speedsprayer in an orchard. The autonomous travel with the FLC was graphically simulated under the conditions of an ordinary standard orchard. Differential global positioning system(DGPS) was used to find the direction of running and four ultrasonic sensors were used to detect obstacles during the running. The simulation results showed that the speedsprayer, by the FLC combined with DGPS and the ultrasonic sensors. could overcome the turning problem at comers which could not be solved with such a system as machine vision and might be operated autonomously.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.12a
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• pp.698-703
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• 1999

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06a
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• pp.119-124
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• 1996

• Journal of Biosystems Engineering
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• v.23 no.3
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• pp.291-304
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• 1998

A control algorithm fir the unmanned vehicles was developed using image information received through a CCD camera that acquires more powerful information over the wide range of wave-length comparing with other sensors and was applied to a speed-sprayer. The algorithm consisted of straight mode for passing along with middle of two tree-rows and turning mode for changing from a row to another row. In case of turning mode, two marks of colored papers were employed to indicate turning point and to decide turning direction for various orchard situations. The method of analysis and image would be differed according to camera's tilt-angle and position that is set on the speed-sprayer. Hence, it analyzed the point of difference by making camera's up and downward tilt-angle.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1998.12a
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• pp.487-492
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• 1998