馬鈴薯播種機的性能評估外文翻譯@中英文翻譯@外文文獻翻譯

中國地質(zhì)大學(xué)長城學(xué)院 本科畢業(yè)論文外文資料翻譯 系 別： 專 業(yè)： 姓 名： 學(xué) 號： 20* 年 03月 10 日 外文資料翻譯譯文 馬鈴薯播種機的性能評估 大多數(shù)馬鈴薯播種機都是通過勺型輸送鏈對馬鈴薯種子進行輸送和投放。當種植精度只停留在一個 可接受水平的時候這個過程的容量就相當?shù)汀Ｖ饕南拗埔蛩厥牵狠斔蛶У乃俣纫约叭∈砩椎臄?shù)量和位置。假設(shè)出現(xiàn)種植距離的偏差是因為偏離了統(tǒng)一的種植距離，這主要原因是升運鏈式馬鈴薯播種機的構(gòu)造造成的 . 一個理論的模型被建立來確定均勻安置的馬鈴薯的原始偏差，這個模型計算出兩個連續(xù)的馬鈴薯觸地的時間間隔。當談到模型的結(jié)論時，提出了兩種假設(shè)，一種假設(shè)和鏈條速度有關(guān)，另一種假設(shè)和馬鈴薯的形狀有關(guān)。為了驗證這兩種假設(shè)，特地在實驗室安裝了一個種植機，同時安裝一個高速攝像機來測量兩個連續(xù)的馬鈴薯在到達土壤表層時的時間間隔以及馬鈴薯 的運動方式。 結(jié)果顯示：（ a）輸送帶的速度越大，播撒的馬鈴薯越均勻；（ b）篩選后的馬鈴薯形狀并不能提高播種精度。 主要的改進措施是減少導(dǎo)種管底部的開放時間，改進取薯杯的設(shè)計以及其相對于導(dǎo)種管的位置。這將允許杯帶在保持較高的播種精度的同時有較大的速度變化空間。 介紹說明 升運鏈式馬鈴薯種植機（圖一）是當前運用最廣泛的馬鈴薯種植機。每一個取薯勺裝一塊種薯從種子箱輸送到傳送鏈。這條鏈向上運動使得種薯離開種子箱到達上鏈輪， 在這一點上， 馬鈴薯種塊 落在 下一個取薯勺的背面 ，并局限于金屬導(dǎo)種 管 內(nèi) . 在底部，輸送鏈通過下鏈 輪獲得足夠的釋放空間使得種薯落入地溝里。 圖一，杯帶式播種機的主要工作部件：（ 1）種子箱；（ 2）輸送鏈；（ 3）取薯勺；（ 4）上鏈輪；（ 5）導(dǎo)種管；（ 6） 護種壁 ；（ 7）開溝器；（ 8）下鏈輪輪；（ 9）釋放孔；（ 10）地溝。 株距和播種精確度是評 價機械性能的兩個主要參數(shù)。高精確度將直接導(dǎo)致高產(chǎn)以及馬鈴薯收獲時的統(tǒng)一分級 (McPhee et al, 1996； Pavek & Thornton, 2003)。在荷蘭的實地測量株距（未發(fā)表的數(shù)據(jù)）變異系數(shù)大約為 20%。美國和加拿大早期的研究顯示，相對于玉米和甜菜的精密播種，當變異系數(shù)高達 69%(Misener, 1982； Entz & LaCroix, 1983； Sieczka et al, 1986)時，其播種就精度特別低。 輸送速度和播種精度顯示出一種逆相關(guān)關(guān)系，因此，目前使用的升運鏈式種植機的每條輸 送帶上都裝備了兩排取薯勺而不是一排。雙排的取薯勺可以使輸送速度加倍而且不必增加輸送帶的速度。因此在相同的精度上具有更高的性能是可行的。 該研究的目的是調(diào)查造成勺型帶式種植機精度低的原因， 并利用這方面的知識提出建議，并作設(shè)計上的修改 。例如在輸送帶的速度、取薯杯的形狀和數(shù)量上。 為了便于理解，建立一個模型去描述馬鈴薯從進入導(dǎo)種管到觸及地面這個時間段內(nèi)的運動過程，因此馬鈴薯在地溝的運動情況就不在考慮之列。由于物理因素對農(nóng)業(yè)設(shè)備的強烈影響 (Kutzbach, 1989)，通常要將馬鈴薯的形狀考慮進模型中。 兩種零假 設(shè)被提出來了：（ 1）播種精度和輸送帶速度無關(guān)；（ 2）播種精度和篩選后的種薯形狀（尤其是尺寸）無關(guān)。這兩種假設(shè)都通過了理論模型以及實驗室論證的測試。 材料及方法 2.1 播種材料 幾種馬鈴薯種子如圣特、阿玲達以及麻佛來都已被用于升運鏈式播種機測試，因為它們 有不同的形狀特征。對于種薯的處理和輸送來說，種薯塊莖的形狀無疑是一個很重要的因素。許多形狀特征在結(jié)合尺寸測量的過程中都能被區(qū)分出來 (Du & Sun, 2004； Tao et al, 1995； Zdler, 1969)。在荷蘭，馬鈴薯的等級主要是由馬鈴薯 的寬度和高度（最大寬度和最小寬度）來決定的。種薯在播種機內(nèi)部的整個輸送過程中，其長度也是一個不可忽視的因素 。 形狀因子 S 的計算基于已經(jīng)提到的三種尺寸： 此處 l 是長度， w 是寬度， h 是高度（單位： mm） ，且 hw001 m 時，這種關(guān)系是線性的。 ，測量數(shù)據(jù) ； ，數(shù)學(xué)模型 的數(shù)據(jù)； ，延長 到 R 0 01 米 ； -，線性關(guān)系 ； R2，決定系數(shù) 。 3.2 馬鈴薯的尺寸和形 狀 實驗數(shù)據(jù)由表三給出。顯示固定進料率為每分鐘 400 個種薯的時間間隔的標準偏差。這 些結(jié)果與期望值剛好相反，即高的標準偏差將使得形狀因子增加。球狀馬鈴薯的結(jié)果尤其令人吃驚：球的標準偏差高過阿玲達馬鈴薯 50%以上。時間間隔的正態(tài)分布如圖七所示，球和馬鈴薯之間的差異明顯。兩個不同品種的馬鈴薯之間的差異不明顯。 表三 馬鈴薯品種對種植間距的精確度的影響 品種 標準偏差 ， ms CV, % 阿玲達 8.60 30 麻佛來 9.92 35 高爾夫球 13.24 46 圖七，固定進料率下不同形狀的沉積的馬鈴薯時間間隔的正態(tài)分布。 球狀馬鈴薯的這種結(jié)果是因為球可以以不同的方式在取薯勺背部定位。臨近杯中球的不同定位導(dǎo)致沉積精度降低。杯帶的三維視圖顯示了取薯勺與導(dǎo)種管之間的間隔的形狀，顯然獲得不同大小的開放空間是可行的。 圖八，取薯勺呈 45 度時的效果圖；馬鈴薯在護種壁的位置對其釋放具有決定性影響。 阿玲達塊莖種薯在沉積時比麻佛來的精度高。通過對記錄的幀和馬鈴薯的分析，結(jié)果表明：阿玲達這種馬鈴薯總是被定位平行于最長的軸線的護種壁。因此，除了形狀因子外，寬度與高度的高比例值也將造成更大的偏差。阿玲達的這個比例是 1.09，麻佛來的為 1.15。 3.3 實驗室對抗模型測試平臺 該數(shù)學(xué)模型預(yù)測了不同情況下的流程性能。相對于馬鈴薯，該模型對球模擬了更好 的性能，然而實驗測試的結(jié)果卻恰然相反。 另外實驗室試驗是為了檢查模型的可靠性。 在該模型里，兩個馬鈴薯之間的時間間隔被計算出來。起始點出現(xiàn)在馬鈴薯開始經(jīng)過 A 點的時刻，終點出現(xiàn)在馬鈴薯到達 C 點的時刻。通過實驗平臺，從 A 到 C 點的馬鈴薯的時間間隔被測出。每個馬鈴薯的長度、寬度和高度也通過測量獲得，同時記錄了馬鈴薯的數(shù)量。測量過程中馬鈴薯在取薯杯上的位置是已經(jīng)確定好的。這個位置和馬鈴薯的尺寸將作為模型的輸入量，測量過程將阿玲達與麻佛來以 400 個馬鈴薯每分的速率下進行。測量時間間隔的標準偏差如表四所示。測量的標準誤差與 模型的標準誤差只是稍稍不同。對這種不同現(xiàn)象的解釋是：（ 1）模型并沒有把圖八中出現(xiàn)的情況考慮進去；（ 2）從 A 點到 C 點的時間不一致。塊狀馬鈴薯如阿玲達可能從頂部或者最遠距離下落，這將導(dǎo)致種薯到達 C 點底部的時間增加 6ms 表四 通過實驗室測量和模型計算出來的開放時間的標準誤差的差異 品種 形狀因子 標準偏差 , ms 測量值 計算值 阿玲達 326 8.02 5.22 麻佛來 175 6.96 4.40 4. 總結(jié) 這個模擬馬鈴薯從輸送帶開始釋放的運動的數(shù)學(xué)模型是一個非常有用的證實假設(shè)和設(shè)計實驗平臺的工具。 模型和實驗室的測試都表明：鏈速越高，馬鈴薯在零速度水平沉積得更均勻。這是由于開口足夠大使得馬鈴薯下降得越快，這對馬鈴薯的形狀和種薯在取薯杯上 的定位有一定的影響，與鏈條速度的關(guān)系也就隨之明確，因此，在保持高的播種精度時，應(yīng)該提供更多的空間以減小鏈條的速度。建議降低鏈輪的半徑，直至低到技術(shù)上的可行度。 該研究顯示，播種機的取薯勺升運鏈鏈對播種精度（播種的幅寬）有很大的影響。 更規(guī)格的形狀（形狀因子低）并不能自動提高播種精度。小球（高爾夫球）在很多情況下沉積的精度低于馬鈴薯，這是由導(dǎo)向的導(dǎo)種管和取薯勺的形狀決定的。 因此建議重新設(shè)計取薯勺和導(dǎo)種管的形狀，要做到這一點還應(yīng)該將小鏈輪加以考慮。 外文原文 Assessment of the Behaviour of Potatoes in a Cup-belt Planter The functioning of most potato planters is based on transport and placement of the see potatoes by a cup-belt. The capacity of this process is rather low when planting accuracy has to stay at acceptable levels. The main limitations are set by the speed of the cup-belt and the number and positioning of the cups. It was hypothesized that the inaccuracy in planting distance, that is the deviation from uniform planting distances, mainly is created by the construction of the cup-belt planter. To determine the origin of the deviations in uniformity of placement of the potatoes atheoretical model was built. The model calculates the time interval between each successive potato touching the ground. Referring to the results of the model, two hypotheses were posed, one with respect to the effect of belt speed, and one with respect to the inuence of potato shape. A planter unit was installed in a laboratory to test these two hypotheses. A high-speed camera was used to measure the time interval between each successive potato just before they reach the soil surface and to visualize the behaviour of the potato. The results showed that: (a) the higher the speed of the cup-belt, the more uniform is thedeposition of the potatoes； and (b) a more regular potato shape did not result in a higher planting accuracy. Major improvements can be achieved by reducing the opening time at the bottom of the duct and by improving the design of the cups and its position relative to the duct. This will allow more room for changes in the cup-belt speeds while keeping a high planting accuracy. 1. Introduction The cup-belt planter (Fig. 1) is the most commonly used machine to plant potatoes. The seed potatoes are transferred from a hopper to the conveyor belt with cups sized to hold one tuber. This belt moves upwards to lift the potatoes out of the hopper and turns over the upper sheave. At this point, the potatoes fall on the back of the next cup and are confined in a sheet-metal duct. At the bottom, the belt turns over the roller, creating the opening for dropping the potato into a furrow in the soil. Capacity and accuracy of plant spacing are the main parameters of machine performance.High accuracy of plant spacing results in high yield and a uniform sorting of the tubers at harvest (McPhee et al., 1996； Pavek & Thornton, 2003). Field measurements (unpublished data) of planting distance in The Netherlands revealed a coefficient of variation (CV) of around 20%. Earlier studies in Canada and the USA showed even higher CVs of up to 69% (Misener, 1982； Entz & LaCroix, 1983； Sieczka et al., 1986), indicating that the accuracy is low compared to precision planters for beet or maize. Travelling speed and accuracy of planting show an inverse correlation. Therefore, the present cup-belt planters are equipped with two parallel rows of cups per belt instead of one. Doubling the cup row allows double the travel speed without increasing the belt speed and thus, a higher capacity at the same accuracy is expected. The objective of this study was to investigate the reasons for the low accuracy of cup-belt planters and to use this knowledge to derive recommendations for design modifications, e.g. in belt speeds or shape and number of cups. For better understanding, a model was developed, describing the potato movement from the moment the potato enters the duct up to the moment it touches the ground. Thus, the behaviour of the potato at the bottom of the soil furrow was not taken into account. As physical properties strongly inuence the efficiency of agricultural equipment (Kutzbach, 1989), the shape of the potatoes was also considered in the model. Two null hypotheses were formulated: (1) the planting accuracy is not related to the speed of the cup-belt； and (2) the planting accuracy is not related to the dimensions (expressed by a shape factor) of the potatoes. The hypotheses were tested both theoretically with the model and empirically in the laboratory. Fig 1. Working components of the cup-belt planter: (1) potatoes in hopper； (2) cup-belt； (3) cup； (4) upper sheave； (5) duct； (6) potato on back of cup； (7) furrower； (8) roller； (9) release opening； (10) ground level 2 .Materials and methods 2.1. Plant material Seed potatoes of the cultivars (cv.) Sante, Arinda and Marfona have been used for testing the cup-belt planter, because they show different shape characteristics. The shape of the potato tuber is an important characteristic For handling and transporting. Many shape features, usually combined with size measurements, can be distinguished (Du & Sun, 2004； Tao et al., 1995； Zodler,1969).In the Netherlands grading of potatoes is mostly done by using the square mesh size (Koning de et al.,1994),which is determined only by the width and height (largest and least breadth) of the potato. For the transport processes inside the planter, the length of the potato is a decisive factor as well. A shape factor S based on all three dimensions was introduced: (1) Where/ is the length, w the width and h the height of the potato in mm, with hw0.01 m, measurement data； data from mathematica model； ,extended for r0.01m) and the accuracy of the deposition of the potatoes. The model was used to estimate standard deviations for different radii at a feeding rate of 300 potatoes min -1.The results are given in Fig. 6, showing that the model predicts a more gradual decrease in accuracy in comparison with the measured data. A radius of 0.025 m, which is probably the smallest radius technically possible, should have given a decrease in standard deviation of about 75% compared to the original radius. 3.2 Dimension and shape of the potatoes The results of the laboratory tests are given in Table 3. It shows the standard deviations of the time interval at a fixe feeding rate of 400 potatoes min-1. These results were contrary to the expectations that higher standard deviations would be found with increasing shape factors. Especially the poor results of the balls were amazing. The standard deviation of the balls was about 50% higher than the oblong potatoes of cv. Arinda. The normal distribution of the time intervals is shown in Fig. 7. Significant differences were found between the balls and the potatoes. No significant differences were found between the two potato varieties. The poor performance of the balls was caused by the fact that these balls could be positioned in many ways on the back of the cup. Thus, different positions of the balls in adjacent cups resulted in a lower accuracy of deposition. The three-dimensional drawing of the cup- belt shows the shape of the gap between cup and duct illustrating that different opening sizes are possible (Fig.8). Table 3 Effect of cultivars on the accuracy of plant spacing； CV, coefficient of variation Cultivar Standard deviation, ， ms CV, % Arinda 8.60 30 Marfona 9.92 35 Golf balls 13.24 46 Fig.7. Normal distribution of the time interval (x, in ms) of deposition of the potatoes for different shaps factors at a fixed Fig 8. View from below to the cup at an angle of 45 degrees； position of the potato on the back of the cup is decisive for its release Arinda tubers were deposited with a higher accuracy than Marfona tubers. Analysis of the recorded frames and the potatoes, demonstrated that the potatoes of cv. Arinda always were positioned with their longest axis parallel to the back of he cup. Thus, apart from the shape factor, a higher ratio width/height will cause a greater deviation. For cv. Arinda, this ratio was 1.09, for cv. Marfona it was 1.15. 3.3. Model versus laboratory test-rig The mathematical model predicted the performance of the process under different circumstances. The model simulated a better performance for spherical balls compared to potatoes whereas the laboratory test showed the opposite. An additional laboratory test was done to check the reliability of the model. In the model, the time interval between two potatoes is calculated. Starting point is the moment the potato crosses line A and end point is the crossing of line C (Fig. 2). In the laboratory test-rig the time-interval between potatoes moving from line A to C was measured (Fig. 3). The length, width and height of each potato was measured and potatoes were numbered. During the measurement it was determined how each potato was positioned on the cup. This position and the potato dimensions were used as input for the model. The measurements were done at a feeding rate of 400 potatoes min-1 with potatoes of cv. Arinda and Marfona. The standard deviations of the measured time intervals are shown in Table 4. They were slightly differen (higher)from the standard deviations calculated by the model. Explanations for these differences are: (1) the model does not take into consideration situations as shown in Fig. 8, (2) the passing moment at line A and C was disputable. Oblong potatoes such as cv. Arinda may fall with the tip or with the longest size down. This may cause up to 6 ms difference for the potato to reach the bottom line C. Table 4 Differences between the standard deviations of the opening time measured in the laboratory and calculated by the model Cultivar Shape factor Standard deviation, ms Measured Calculated Arinda 326 8.02 5.22 Marfona 175 6.96 4.40 4. Conclusions The mathematical model simulating the movement of the potatoes at the time of their release from the cup-belt was a very useful tool leading to the hypotheses to be tested and to design the laboratory test-rig. Both the model and the laboratory test showed that the higher the speed of the belt, the more uniform the deposition of the potatoes at zero horizontal velocity. This was due to the fact that the opening, allowing the potato to drop, is created quicker. This leaves less effect of shape of the potato and the positioning of the potato on the cup. A relationship with the belt speed was found. So, to provide more room for reductions in the cup-belt speeds while keeping a high planting accuracy it is recommended to decrease the radius of the roller till as low as technically possible. This study showed that the accuracy of planting (distance in the seeding furrow) is inuenced for a large part by the cup-belt unit of the planter. A more regular shape lower shape factor) does not automatically result in a higher accuracy. A sphere (golf ball) in most cases was deposited with a lower accuracy than a potato. This was caused by the shapes of the guiding duct and cups. It is recommended to redesign the geometry of the cups and duct, and to do this in combination with a smaller roller. Acknowledgements Acknowledgements are made to Miedema bv for financial support and making available a planting unit for the laboratory test-rig. The Animal Science group of Wageningen University provided the high-speed video camera. References DuCheng-Jin； SunDa-Wen (2004) Recent developments in the applications of image processing techniques for