The aim of this study was to develop an obstacle avoidance system using a 3D camera. A noise filtering algorithm was used to detect corrupted pixels and a background removal method was used to distinguish obstacles from the background. A clustering algorithm based on a 2D histogram back-projected obstacle pixels onto the ground plane for image segmentation and analysis. Experiments showed that this system had a maximum error of 10 cm and an RMS error of 5.6 cm for position accuracy under static conditions and an RMS error of 7.1 cm in distance detection under moving conditions. Field tests showed that the developed system could effectively detect obstacles in real-time.

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This paper describes a new method for extracting the agricultural land use pattern around the Miyajimanuma inland wetland based on remote sensing imagery. A land parcel and particle swarm optimization (PSO) K-means-based minimum distance classification (MDC) (LP-PSOK-MDC) method was developed. This method includes three steps: 1) considering the diversity of crop planting and growth state, a training sample pre-classification-based MDC method was developed; 2) the land parcels information was extracted by using watershed transform algorithm; finally, 3) pixels in the same land parcel were re-classified. Results of the study suggest that using this method the classification result was easily up to 96 %, much better than results obtained by using traditional supervised classification methods such as MDC and unsupervised classification method.

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Unshu citrus were sorted by fluorescence imaging in a commercial packinghouse and undamaged-appearing unshu that had been rejected by the packinghouse due to fluorescence appearing on their peel were studied. We examined the various visible patterns, based upon fluorescence and microscopic images, to provide a categorization of physical reasons for the observed fluorescence. The categorization classes were: 1) slight physical damage: thin scar, hole and flow, shrunken at calyx; 2) rubbing against decayed fruits; 3) green spots; and 4) rind puffing. The percentage of observation for each of the four classes was 22 %, 15 %, 42 % and 21 %, respectively. Storage of the classes indicated that, except for the green spot class, the injured area expanded quickly and caused the fruits to rot within a week.

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The study aims to apply an autonomous path-following control for a head-feeding combine robot. A real-time kinematic global positioning system (RTK-GPS) and a GPS compass are used as navigation sensors. These sensors provide the combine robot with the position and heading information required to steer along a target path. To control steering, we applied a Kalman filter that estimates the lateral and heading errors contained in the position, heading, and traveling-speed data. Through field experiments, we demonstrated that the combine robot is capable of automatically following a target spiral path and harvesting rice crops.

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Carbon sequestration through agricultural soil is increasingly promoted as a win-win strategy for mitigating climate change and improving farmers' livelihoods, especially in dry land. A better understanding of agricultural management for paddy fields that can increase both soil carbon and household income is therefore necessary. Using a DeNitrification–DeComposition (DNDC) model, this paper evaluates different farming management practices both by their capacity of carbon sequestration and contribution to household income, thereby to identify the optimal carbon-capturing farming practices for paddy fields. A real-time soil sensor and several comprehensive field surveys were employed for data collection. The farming practices of no-till, reduced tillage combing increased organic fertilizers were identified as cost-effective strategies to increase carbon sequestration in the paddy fields of Matsuyama.

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This study provides an overview of soil mechanical conditioning and the development of a low-cost stone-clod separator for a new cultivation system (NCS) of potatoes in Hokkaido. Field tests showed that the soil-crushing performance and the working hours of the developed separator were the same as those of an expensive imported machine. The quantity of clods conveyed to the furrows and the working hours of the developed separator were 5.6 t / ha and 0.45 ha / h, respectively. The NCS had several advantages over the conventional cultivation system, such as significantly (p ≤ 0.01) fewer distorted potatoes and significantly (p ≤ 0.01) fewer stone-clods mixed with potatoes during machine harvesting. The NCS also reduced labor input for potato harvesting by approximately 28 %.

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