巻号一覧
45 巻 (1989 - 1990)
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- 3 号 p. 137-
- 2 号 p. 87-
- 1 号 p. 1-
45 巻, 2 号
選択された号の論文の8件中1～8を表示しています
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庄野 浩資, 天羽 弘一, 高倉 直1989 年 45 巻 2 号 p. 87-92
発行日: 1989/09/10
公開日: 2010/02/25
ジャーナル フリーA method to detect cucumber fruits in the canopy using image processing technique has been studied, with the aim of robotic harvesting. This method distinguishes a fruit from the other parts of the plant, not by the difference in their colors, but by the difference in shapes.
The brightness in the digitized image was differentiated in horizontal direction, and clipped into three values (+, 0, -) by two thresholds. Then ridge-lines were drawn between (+) value area and (-) value area.
The ridge-line images ordinarily contain some noise from the other parts of the plant. Accordingly, two images for the same scene were taken, one was illuminated from the left and the other was illuminated from the right. The center line image was obtained by comparing the two ridgeline images in consideration of the shift of the fruit's ridge-line which was calculated by a model. After the noise was reduced in the center line image, the center line of the fruit remained.
This method contains four unknown parameters, and it was found that these parameters have the optimum value. But there were some deviations in the optimum values obtained from different images. The deviations were not so severe as to make the detection impossible in our experiment, but in general it is necessary to determine the optimum values applicable to many other scenes.
This method was applied to some images taken in the field, and showed that it was able to detect the fruit when it was fully illuminated from both sides. The detection, however, became difficult when the light was intercepted by leaves and the illumination for the fruit was not enough.抄録全体を表示PDF形式でダウンロード (2196K) -
天羽 弘一, 高倉 直1989 年 45 巻 2 号 p. 93-97
発行日: 1989/09/10
公開日: 2010/02/25
ジャーナル フリーA robotic hand for harvesting cucumber fruits has been developed. The hand is capable to follow the curved shape of a located fruit and to detect and cut its peduncle.
The hand consists of three parts, the gripper, the sensor and cutter, and the free connector. The gripper serves to grasp and hold a fruit. The sensor and cutter travels up following the shape of the grasped fruit. The sensor detects where the peduncle is by measuring the diameter of the fruit continuously until the diameter is sensed to be less than 8 (mm), at which point, it is judged to be the peduncle. The cutter then rotates and cuts the peduncle to release the fruit from the canopy. If the fruit is curved, the sensor and cutter can move upwards following the curved shape by means of the free connector. The free connector has two degrees of freedom of rotation and one of expansion and contraction. The hand is also designed to handle fruits gently without inflicting damage.
Motion tests have been made with real cucumber fruits in the laboratory. The fruits in these tests were placed in the hand manually. It was concluded as follows.
1) The hand could follow the shape of most fruits except for those that were very curved.
2) The sensor could detect all peduncles except for those that were heavily curved, which the hand could not follow.
3) The cutter was successful in cutting the peduncles.
It is necessary to improve the hand so that severely curved fruits can be followed, and to do additional motion tests with randomly selected fruits in order to establish the percentage of fruits which can be harvested. The most important subject for future study would be to test the hand in a real canopy.抄録全体を表示PDF形式でダウンロード (1875K) -
1989 年 45 巻 2 号 p. 98
発行日: 1989/09/10
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (178K) -
星 岳彦, 岡野 利明, 寺添 斉, 吉原 利一, 斎木 博1989 年 45 巻 2 号 p. 99-104
発行日: 1989/09/10
公開日: 2010/02/25
ジャーナル フリーNutrient solution in hydroponics is usually covered with the shading material, plate or film. A hydroponic vegetable production system which uses a movable vegetable supporting mechanism for varying the space among vegetables according to the growth stage, called “spacing”, was developed. For easy spacing, it is desirable not to use the shading material on the nutrient solution. Then, the nutrient solution is exposed to the light. There are a number of unclarified points concerned with the effects of the lighted nutrient solution on vegetables growth.
Two experiments were performed. In experiment 1, to observe the effects on vegetables growth, spinach (Spinacia oleracea) and Senpoh-sai (Brassica×hybrida) were planted in two hydroponic beds. One bed was covered with the shading plate to keep the nutrient solution dark, and the other bed was not covered to expose the solution to the light. In experiment 2, to investigate hourly changes of the composition of the nutrient solution, the nutrient solution was illuminated with white fluorescent lamps.
The top fresh weight of spinach 17 days after transplanting to the lighted nutrient solution decreased to 36% of the control. The primary cause of vegetable growth inhibition was considered to be iron deficit induced by changing of soluble iron (EDTA-Fe) into insoluble one (FePO4).
94% of soluble iron in the nutrient solution under the lighting intensity of 240μmol/m2/sec changed into insoluble iron for 42 hours. When the lighting intensity in the nutrient solution is reduced to 11.8μmol/m2/sec by shading, the change of soluble iron into insoluble one is controlled at 5% increase per day compared with case of quite dark condition.
These results will provide clues for studying on soluble iron condition of nutrient sterilization using ultra violet lay and tissue culture medium of a transparent vessel.抄録全体を表示PDF形式でダウンロード (2738K) -
小沢 聖, 斉藤 祥子, 島根 茂雄1989 年 45 巻 2 号 p. 105-109
発行日: 1989/09/10
公開日: 2010/02/25
ジャーナル フリーExperiments were conducted to confirm that roots stemming from a tomato plant could possess different function to ease adverse environmental effects.
Three lateral shoots of forth foliage stage tomato were forced to grow continuously, other growing points being removed. Two of these shoots were then allowed to roots in humid sand media. The original plant roots were cut off, and the plants were grown hydroponically with rooted lateral shoots in nutrient solutions of either single or two concentrations.
Plant hight, leaf water potential, water and nutrient uptake decreased substantially when their roots were immersed in water or single higher concentrated solution. These responses, however, recovered up to nearly normal level in plants having the roots separately dipped in two solutions of different concentrations. This fact suggest that when roots are separated into two parts and grown in solutions of different concentrations, the roots in a better environment decrease the damage.抄録全体を表示PDF形式でダウンロード (1889K) -
鈴木 義則, 早川 誠而1989 年 45 巻 2 号 p. 111-115
発行日: 1989/09/10
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (4683K) -
信 廼詮1989 年 45 巻 2 号 p. 117-119
発行日: 1989/09/10
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (422K) -
若手研究者の会1989 年 45 巻 2 号 p. 121-122
発行日: 1989/09/10
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (274K)
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