升運鏈式馬鈴薯播種機的設計,鏈式,馬鈴薯,播種機,設計 山 西 農 業(yè) 大 學 本科生畢業(yè)論文（設計）選題審批表 畢業(yè)論文（設計）題目 馬鈴薯播種機具設計 指 導 教 師 左月明 職 稱 教授 學生具備條件 熟練做圖的能力、演算的能力，以及獨立分析問題的能力 選題完成形式 畢業(yè)設計說明書和圖紙 內 容 簡 要： 馬鈴薯是我國主要的糧食作物之一，在我國得到大面積栽種。2007年，我國馬鈴薯種植面積和產量都位居世界首位，然而盡管總產量大，但是單產量卻很低。造成這一原因的主要因素是種植方式和機械化水平的落后。因此，當前的主要任務就是提高馬鈴薯種植的單產量。提高馬鈴薯單產量有兩個途徑：一是改進種植方式；二是提高機械化種植水平。而提高機械化生產水平是最有效的方式，這就要求各種性能先進，種植效率高，通用性和適應性強，結構簡單易于制造與維修的馬鈴薯種植機不斷被設計出來并得到大力的推廣與應用。升運鏈式馬鈴薯播種機是一種塊狀馬鈴薯播種機，其結構簡單，工作可靠，效率高，不傷種，在國內外正逐漸得到廣泛的應用。 系主任簽字： 年 月 日 院長簽字： 年 月 日 2 山西農業(yè)大學 本科生畢業(yè)論文(設計) 開題報告 題 目 馬鈴薯播種機具設計 學院名稱 工程技術學院 專業(yè)名稱 機械設計制造及其自動化 年 級 2005級 學生姓名 郭小君 學 號 03 指導教師 左月明 職 稱 教授 2009年6月12日 選題的依據及意義（包括課題的理論價值和實踐價值；國內外的研究概況等）： 馬鈴薯是一種高蛋白農作物，在我國得到廣泛地栽種。2007年我國馬鈴薯種植面積約8000萬畝，總產量超過6800萬噸，占世界總產量的22%左右（www.potatoweb.cn ，2007年）。單從總產量來說我國已經是世界第一，但是單產量卻遠遠低于歐美和澳洲的水平。例如，2003年，我國馬鈴薯的單產量是每公頃14842公斤，低于世界平均水平每公頃16448 公斤，還不到單產量最大的國家新西蘭每公頃44248 公斤的三分之一（www.potatoweb.cn ，2007年）。 我國馬鈴薯種植單產量很低這已是不爭的事實，因此，我國應該把提高馬鈴薯的單產作為目前提高馬鈴薯產量的首要任務。提高馬鈴薯單產的措施除了提高機械化生產水平外，還應該改進馬鈴薯的種植方式。 提高單產量，首要任務就是提高機械化生產水平。當前，除少部分地區(qū)已經實現馬鈴薯機械化或半機械化種植以外，我國大部分的馬鈴薯種植方式一直停留在傳統(tǒng)種植的水平上，傳統(tǒng)的種植方式主要依靠人力和畜力進行生產，從開溝到覆土鎮(zhèn)壓，整個過程勞動強度大，生產效率低，種植效果也遠遠低于機械化種植水平；而且我國地域廣闊，擁有多種地型，因此需要的播種機的機型也相對不一，設計出具有較強適應性的播種機將成為未來播種機發(fā)展的必然趨勢；播種機的通用性也是一個不可忽略的重要因素，提高播種機的通用性有助于提高播種機的使用性能，使得播種機得到充分的利用。雖然從當前的情況來看，我國在播種機這塊領域還不能一下子縮小同國外發(fā)達國家之間的差距，但是正在將這種差距正在不斷縮小。 傳統(tǒng)的馬鈴薯種植方式也是一個制約馬鈴薯單產量提高的重要因素，主要體現在：（1）馬鈴薯種子的質量不高，我國種植馬鈴薯的大部分地區(qū)，馬鈴薯種子一般是自留的，沒有經過消毒，殺菌以及其它提高種植質量的技術處理，因此種出來的馬鈴薯質量和產量不高；（2）種薯的品種不全，不同的地區(qū)，不同的氣候往往需要不同的馬鈴薯種子，在這方面，我國所作的研究還遠遠不能滿足其需求，因此，在今后更應該加大對馬鈴薯品種的研制；（3）傳統(tǒng)的種植方式主要靠人力和畜力，工作量大而且工作效率低，對土壤的壓實比較嚴重，這對種子的發(fā)芽和生長極為不利。 本課題研究內容 （1）馬鈴薯播種機具的總體設計 （2）馬鈴薯播種機傳動機構的設計 （3）馬鈴薯播種機開溝裝置的設計 （4）馬鈴薯播種機排種裝置的設計 （5）馬鈴薯播種機輸種管、鎮(zhèn)壓裝置以及行走輪的設計 本課題研究方案 總體方案擬將開溝裝置、施肥裝置、排種裝置、覆土裝置及鎮(zhèn)壓裝置與選用拖拉機融為一體，使之能一次性順利完成開溝、施肥、播種、覆蓋、鎮(zhèn)壓等功能，懸掛機構要有效的控制工作部件作業(yè)時的播深以及運輸時的通過性，開溝器除了能開出平整的地溝外還具備自動覆土的功能；排種裝置確保在播種過程中出現漏播、重播等現象的幾率不超過3%。鎮(zhèn)壓輪要求鎮(zhèn)壓效果好，作業(yè)后的地面平整。 研究的創(chuàng)新之處 該馬鈴薯播種機由機架、開溝器、輸種管、輸肥管、覆土器、種箱、肥箱、排種器以及鎮(zhèn)壓輪構成，在機架的前梁上有上、下懸掛架用于與拖拉機連接；種、肥箱側板固定在機架中間橫梁的上方，前邊為肥箱，后邊為種箱，下邊固定排肥、排種裝置；在肥箱前面有一根安裝開溝器的梁，通過U型螺栓將開溝器的扁鋼鎖住，從而可以調節(jié)開溝深度，開溝器在橫梁上可根據需要進行橫向移動來調節(jié)行距；機架的后梁用來連接鎮(zhèn)壓輪。 地輪隨拖拉機前進而轉動，由地輪傳遞動力，在地輪軸的兩端各裝一個傳動鏈輪, 通過鏈條將力矩傳給中間傳動鏈輪，再由中間鏈輪將動力傳給排種排肥裝置,通常情況下地輪直徑較大，工作時不易發(fā)生打滑等現象，并且傳動可靠。 播種機工作時，拖拉機通過動力輸出軸將動力傳遞給行走輪，行走輪上的主動軸將動力傳遞給中間軸，行走輪隨拖拉機前進而轉動，通過鏈條將動力傳給施肥、播種機構，排出的化肥和種子經輸肥管與輸種管進入開溝器，先后進入開好的地溝中，為了避免燒壞種薯，化肥應位于種子下方5 cm 處，覆土器進一步覆蓋種溝，鎮(zhèn)壓輪的圓錐滾筒隨即以均勻適當的壓力壓密種床 7 研究過程(含完成期限) 第5周——查閱相關馬鈴薯播種機的設計資料，并進行概述和文獻綜合。 第 6周——完成馬鈴薯播種機排種施肥機械傳動原理圖。 第7-9周——完成傳動部分的機械設計并繪制裝配圖。 第10-12周——完成鎮(zhèn)壓輪及行走輪的機械設計并繪制裝配圖和部分零件圖。 第13周——完成所有的圖紙并進一步修改。 第14-15周——在以上基礎上完成畢業(yè)論文一篇。 第16周——翻譯一篇與論文相關的外文資料。 第17周——答辯。 指導教師意見 指導教師簽名： 年 月 日 教研室意見 教研室主任簽名： 年 月 日 院系意見 主管領導簽名： 年 月 日 畢 業(yè) 論 文 論文題目 學 院 專 業(yè) 年 級  姓 名 指導教師  職 稱  （200 年 月） 山西農業(yè)大學教務處制 畢業(yè)論文（設計）指導教師評審標準 序號 評審項目 指 標 滿分 1 工作量、工作態(tài)度 按期圓滿完成規(guī)定的任務，難易程度和工作量符合教學要求，體現本專業(yè)基本訓練的內容；工作認真，遵守紀律；作風嚴謹務實。 20 2 調查論證 能獨立查閱文獻和調研；能正確翻譯外文資料；能較好地作出開題報告；有綜合、收集和正確利用各種信息的能力。 15 3 設計、實驗方案 與實驗技能 設計、實驗方案科學合理，方案具體可行；能獨立操作實驗，數據采集、計算、處理正確；結構設計合理、工藝可行、推導正確或程序運行可靠。 20 4 分析與解決 問題的能力 能運用所學知識和技能及獲取新知識去發(fā)現與解決實際問題；能對課題進行理論分析，并得出有價值的結論 20 5 論文（設計）質量 立論正確，論據充分，結論嚴謹合理；實驗正確，分析、處理問題科學；綜述簡練完整，結構格式符合論文（設計）要求；文理通順，技術用語準確，規(guī)范；圖表完備、制圖正確。 20 6 創(chuàng) 新 具有創(chuàng)新意識；對前人工作有改進、突破、或有獨特見解，有一定應用價值。 5 各教學單位可結合本專業(yè)特點和要求，制定相應的評價標準。 11 畢業(yè)論文（設計）評閱人評審標準 序號 評審項目 指 標 滿分 1 選 題 選題達到本專業(yè)教學基本要求，難易程度、工作量大小合適。 20 2 綜述材料 調查論證 根據課題任務，能獨立查閱文獻資料和從事有關調研。有綜合歸納、利用各種信息的能力，開題論證較充分。翻譯外文資料的水平較高。 15 3 設計、推導、 計算、論證 方案設計合理，具有可操作性；推導正確；計算準確；結構合理、工藝可行；圖樣繪制與技術要求符合國家標準及要求。 45 4 論文設計質量 論點明確，論據充分，結論正確；條理清楚，文理通順，用語符合技術規(guī)范；圖表清楚，書寫格式規(guī)范。 15 5 創(chuàng) 新 對前人工作有改進、突破、或有獨特見解；有一定應用價值。 5 各教學單位可結合本專業(yè)特點和要求，制定相應的評價標準。 畢業(yè)論文（設計）答辯評審標準 序號 評審項目 指 標 滿分 1 報告內容 思路清新；語言表達準確，概念清楚，論點正確；實驗方法科學，分析歸納合理；結論嚴謹，論文（設計）有應用價值。 40 2 報告過程 準備工作充分, 具備必要的報告影像資料；報告在規(guī)定的時間內作完。 10 3 答 辯 回答問題有理論依據，基本概念清楚。主要問題回答簡明準確。 45 4 創(chuàng) 新 對前人工作有改進或突破，或有獨特見解。 5 各教學單位可結合本專業(yè)特點和要求，制定相應的評價標準。 山 西 農 業(yè) 大 學 畢業(yè)論文（設計）成績單 院系 專業(yè) 入學時間 學號 學生姓名 班級 周數 起止日期 指導教師 職稱 論文（設計）題目 指 導 教 師 評 語 建議成績 指導教師簽名 年 月 日 評 閱 人 評 語 建議成績 評閱人簽名 年 月 日 答辯與評分 綜合成績 答辯小組 負責人簽名 年 月 日 本成績單一式二份，一份裝訂在畢業(yè)論文（設計）中，一份入學生學籍檔案。 優(yōu)秀畢業(yè)論文（設計）推薦表 論文題目 　 學生姓名 　 學 號 　 專 業(yè) 　 學 院 　 　指導教師 　 審稿說明： 1.對論文內容、論文質量、學術水平（含文字、圖表、公式）的評價。 2.對論文具體說明推薦的理由。 3.推薦的論文稿件是否符合編寫規(guī)范要求。 推薦人意見： 推薦人簽字： 年 月 日 院長簽字： 年 月 日 14 山西農業(yè)大學學士學位論文（設計）文獻綜述 馬鈴薯播種機具的現狀與發(fā)展 摘要：綜述了國內外播種機的發(fā)展現狀，并通過對國內外幾種典型播種機的各種參數進行系統(tǒng)的對比并加以分析，從中發(fā)現國產播種機與國外播種機的差距，并在此基礎上去闡述我國播種機在研發(fā)和應用上所存在問題并展望未來播種機的發(fā)展趨勢，同時明確馬鈴薯播種機的設計方向。 關鍵詞：播種機具 馬鈴薯 精量播種機 排種器 1. 馬鈴薯在我國的生產現狀 馬鈴薯是一種高蛋白農作物，在我國得到大面積的栽種，盡管我國年產量早已躍居世界第一，然而和世界除非洲以外的其他國家和地區(qū)比起來，單產量卻很低，因此在提高單產的措施上除了提高機械化生產水平外，還應該改進馬鈴薯的種子質量以及種植方式。 1.1我國馬鈴薯的生產現狀 300多年前，原產自美洲的馬鈴薯被引進中國并且逐漸成為僅次于小麥、水稻和玉米的第四大糧食作物。目前，我國的馬鈴薯無論是種植面積還是總產量都處于全球領先地位。從中國馬鈴薯網上獲得的資訊：2007年我國馬鈴薯種植面積約8000萬畝，預計總產量將超過6800萬噸，占世界總產量的22%左右。單從總產量來說我國已經是世界第一，但是單產量卻遠遠低于歐美、澳洲的水平。例如，2003年，我國馬鈴薯的單產量是每公頃14842公斤，低于世界平均水平的每公頃16448 公斤，還不到單產量最大的國家新西蘭的每公頃44248 公斤的三分之一。 1.2國外馬鈴薯的生產水平 單產量排名前六位的國家：新西蘭、比利時、丹麥、美國、英國、荷蘭等歐美發(fā)達國家，他們的單產量都超過了每公頃40000 公斤（中國馬鈴薯網，2007）。除了地域、氣候方面外，更重要的是栽培技術以及機械化生產水平的影響。顯然，這些國家的農業(yè)生產機械化水平都遠遠高過我國。反觀我國，大部分地區(qū)的馬鈴薯生產都還停留在人工或者半機械化生產的水平上，因此單產量低也就不足為奇。 1.3目前急需解決的措施以及會遇到的困難 要想提高單產量，首要的就是提高機械化生產水平。我國地域廣闊，擁有多種地型，因此不可能同時提高生產機械化，所以應該根據不同的地形，不同的氣候和種植方式，從而設計符合當地的農業(yè)生產機械，盡量推廣播種機在農業(yè)生產中的應用。其次應該改進種植方式，我國的馬鈴薯種植方式一直停留在傳統(tǒng)種植的水平上，這是急需改變的。先進的種植方式應該從改進種子質量，改進播種方式等方面進行，同時在此基礎上設計相應的機械也就顯得至關重要。 2. 國內外播種機發(fā)展及應用的現狀 2.1我國播種機發(fā)展現狀 現目前，我國大約有500家播種機生產企業(yè)，但是這些企業(yè)中能夠生產與大中型拖拉機配套的播種機的企業(yè)只有西安農業(yè)機械廠、石家莊市農業(yè)機械廠等區(qū)區(qū)10多家，其余的企業(yè)生產的都是與小型拖拉機和畜力配套的拖拉機。這種與小型拖拉機和畜力配套的播種機機的產量占全國播種機總產量的90%以上（國委文，2007）。由此可以看出當前我國已實現機械化播種的大部分地區(qū)的播種機仍以小型播種機進行傳統(tǒng)的谷物條播為主，大中型播種機的發(fā)展遠遠跟不上農業(yè)生產的需要，而且大中型生產機械（包括播種機）的研制和生產水平也遠遠落后于發(fā)達國家的水平。 2.2國外播種機發(fā)展現狀 相對我國而言，國外許多發(fā)達國家在第二次世界大戰(zhàn)前后，先后完成了由傳統(tǒng)農業(yè)向現代農業(yè)的過度和轉化，經過幾十年的發(fā)展，其農業(yè)機械化水平已經相當完善，現在正朝著大型化、智能化、精量化以及多功能聯(lián)合型方向發(fā)展（陶衛(wèi)民，2001）。美國，德國，英國等西方發(fā)達國家的發(fā)展水平已經走在世界的前列。 在國外許多發(fā)達國家，精密播種機經過幾十年的發(fā)展和應用，其技術水平應經達到了相當完善的程度，無論是工作速度、生產效率、工作性能、播種質量以及播種機具的通用性和適應性上都做得比較好。這對減少播種過程中的漏種率、種子損傷率和提高單產量都有很大的促進作用?，F在一些發(fā)達國家正把不斷更新播種機的工作原理、盡量完善其結構、延長機具使用壽命、降低制造價格和維護費用的同時提高其工作效率以及提高播種機的通用性和適應性作為未來更先進的播種機研制的發(fā)展方向。 2.3與國外播種機相比，我國播種機存在的不足 和國外如美國、德國、英國等發(fā)達國家的播種機比起來，我國的播種機工作效率低，工作幅寬小，通用性和適應性低，使用可靠性不高，生產率也遠較國外的低。另外，由于我國工業(yè)起步晚，因此在新技術的研制和在播種機上的應用上依舊落后于國外發(fā)達國家。下面以我國幾種典型的播種機和國外的播種機作一個對比，以便從中發(fā)現我國播種機和國外先進播種機的不足。 首先，從工作效率方面來看，我國播種機的工作速度低。國外播種機的工作速度大都要求達到15㎞／h，有的甚至達到20㎞／h，受到土地，氣候和一些其它因素的影響，工作速度大多采用8～12㎞／h，而我國工作速度大約為4～7㎞／h，一般工作速度為5～6㎞／h。比如德國早期生產的GL34T和GL36T兩種機型的工作速度為7.5㎞／h(韓文鋒等，2006），而我國普遍采用的2BM-2以及2BMF-2型都達不到德國這兩種機型的水平。 其次，我國播種機的工作幅寬小。和國外發(fā)達國家比起來這個環(huán)節(jié)顯得非常薄弱。例如西歐一些國家的生產的播種機的工作幅寬一般為5～6m，美國，加拿大等國家的現用機型大多可以達到10～15m（陳興田，1999）。而我國所使用的播種機的工作幅寬絕大多數低于3.5m，例如較先進的2BF-24A谷物條播機的工作幅寬為3.6m，其余的大都低于這個水平，工作幅寬低這個瓶頸在很大程度上限制了播種機的工作效率。 再次，排種器的排種效率低。我國很多使用播種機的地區(qū)在農業(yè)生產中依舊使用傳統(tǒng)的排種方式即“一器一行”，一個排種器只能播一行種子，顯然這樣的效率是非常低的，即使有較先進的“一器多行”的排種器，但是技術上也表現得不夠成熟，也沒能進行大規(guī)模的推廣及應用。國外發(fā)達國家在這方面的技術和經驗就比我國先進得多，而且許多新技術已經得到廣泛的應用，許多核心部件尤其是排種器無論是結構還是工作原理都還有很多值得我國學習和借鑒的地方。 最后，我國的播種機的通用性和適應性和國外發(fā)達國家比起來也還有很大的差距。在通用性方面，國外發(fā)展得比較早，技術也比較成熟，一套設備只需經過簡單的更換即可實現不同種子的播種，而我國大部分播種機還都是“一機一種”，一種播種機只能夠播撒一種種子，這樣既浪費制造材料，又沒能使播種機得到充分利用。另外，我國地域遼闊，不同的土壤條件和氣候條件嚴重限制了播種機的適應性，在保證適應性方面的技術還很落后，而且我國研制生產的播種機很少考慮到適應性這一方面的影響。 3. 我國播種機的發(fā)展趨勢 雖然可以通過引進國外先進的播種機可以暫時彌補我國播種機的不足之處，但是從長遠 出發(fā)，我國必須走自主研發(fā)的道路，通過不斷吸收國外先進技術的同時再結合我國的國情走出一條自主創(chuàng)新的路子，研制出具有我國特色的先進播種機。 3.1加大大中型播種機的研制和開發(fā) 要想盡快縮小我國馬鈴薯等農作物的單產與國外水平的差距，大中型播種機將起到至 關重要的作用。我國的幾大平原地勢平坦，比較適合大中型播種機的推廣和應用。大中型播種機械除了可以節(jié)約人力，提高工作效率外還能減少種子的損傷率和漏種率，而且大中型播種機都是朝著聯(lián)合作業(yè)和直接播種技術的方向發(fā)展，這種機械的優(yōu)點在于：一次可以完成多項作業(yè)，作業(yè)效率高；保證及時播種，提高產量；節(jié)約能源，降低成本。 3.2采用新的排種原理和排種裝置 排種裝置是播種機最關鍵的部件，先進的排種器和排種原理對播種機的效率的提高有 著很重要的作用，迄今為止，我國學者幾乎涉獵了世界上所有的排種器：如外槽輪式排種器、離心式排種器、各種圓盤式排種器等，而具有我國獨創(chuàng)特色的窩眼輪式排種器、紋盤式排種器、錐盤式精量排種器也獲得了廣泛的應用，但是在馬鈴薯播種機上，先進的排種器和排種方式依然制約播種機效率的一個瓶頸。因此在已經解決種子和播種方式的情況下研制相應的播種機顯得是關重要。顯然，在排種器方面，我國應該朝著氣流輸送式條播排種器、孔帶式精密排種器、氣力式精密排種器以及傾斜圓盤指夾式排種器的方向發(fā)展。新的排種原理包括氣力式排種原理和機械式排種原理也應得到廣泛的采用（陳興田，1999）。 4. 小結 一個比較先進的播種機主要取決于其幾個關鍵的部件，如：開溝器、仿形機構、覆土器以及排種器。尤其是排種器在整個播種機結構中顯得尤為重要，排種器的好壞直接關系到播種機的播種效率，因此，現在國內外播種機研制的重點依舊是放在排種器的研制上。我國在這方面也有不少的研究，尤其在氣吸式排種器，窩眼式排種器還有氣力式排種器的研究上有了一定的突破，但是和國外先進水平還有一定的差距，因此，我國還必須加大研制的力度。 新型馬鈴薯已經研制成功并將實現大力推廣，在將來的幾年內，相應的馬鈴薯播種機將對這種新型馬鈴薯的推廣起到極大的推動作用。新型的馬鈴薯將徹底改變傳統(tǒng)的馬鈴薯塊莖式播種方式，其播種方式將和玉米，油菜籽等顆粒的播種方式更為相似，但還是存在很多不同的地方，因此不能直接選用像玉米播種機或者油菜籽播種機這些現成的播種機型。由于現目前新型馬鈴薯還沒有開始實現大面積推廣，相應的馬鈴薯播種機具還是一片空白?；诖?，對現有的馬鈴薯播種機和其余各類顆粒式播種機進行改進優(yōu)化并在此基礎上設計一種適合新型馬鈴薯的機械式或者氣吸式播種機就成了當前以及未來相當一段時間內播種機的研制方向，同時研制的重點也將放在馬鈴薯播種機的排種器的研制上。 參考文獻： [1] 李寶筏．農業(yè)機械學．北京：中國農業(yè)出版社， 2003 [2] 朱秉蘭．簡明農機手冊．鄭州：河南科學技術出版社，2001 [3] 張波屏．編譯．播種機械設計原理．北京：機械工業(yè)出版社，1982 [4] 馮小靜．精少量播種機械使用與維修．鄭州：河南科學技術出版社，1998 [5] 馬大敏．王俊民，王秀．新型農機具使用與維修．北京：高等教育出版社，1996 [6] 程興田．播種機械的現狀及發(fā)展前景．農機與食品機械，1999，6：1～2 [7] 陶衛(wèi)民．國外農業(yè)裝備發(fā)展趨勢．新農村，2001，7：25 [8] 劉林生．英國農業(yè)機械化與農業(yè)現代化．湖南農機，1999，2：25 [9] 姜宗昌．2BMF—2型馬鈴薯研制成功．農業(yè)機械化與電氣化，2000，5：34 [10] 魯濱，薛理，閏洪山等．2BS—5型馬鈴薯播種機的研制，2004，6：33 [11] 幾種馬鈴薯播種、種植機械．www.potatoweb.cn ，2007 [12] 聶延輝 江濤．夾持式馬鈴薯播種機的探討，2007，2：41 [13] 周桂霞，張國慶 ，張義峰等．2CM一2型馬鈴薯播種機的設計．黑龍江八一農墾大學報，2004，16（3）：53～56 [14] 趙滿全，趙有杰，竇衛(wèi)國等．2BM—9型免耕播種機關鍵部件的設計與研究．中國農機化，2006，6： [15] 韓文鋒，王淑紅．徐長征．GL3 4T／3 6 T型馬鈴薯播種機簡介，2007， 1：41 [16] 馮小靜，劉俊峰，楊欣等．排種器排種均勻性分析與研究．河北農業(yè)大學學報，2003， 1：14～16 [17] 趙滿全，竇衛(wèi)國，趙士杰，等．2BSL一2型馬鈴薯起壟播種機的研制．內蒙古農業(yè)學學報，2001， (3)：l02～l04 [18] 閏建英，樊文憲，馮占懷．馬鈴薯施肥播種機的實驗研究．農機科技推廣，2004，4：34 [19] 王廣勝，王玉忠，樊文憲．2BXSM—IB型馬鈴薯施肥播種機的研究．農機與食品機械 ，1999，(3)：l5～17． [20] 國委文．播種機的現狀及發(fā)展趨勢。農業(yè)機械化與電氣化，2007，5：3～4 [21] KACHMAN S D．Acternative Measures of Accuracy in Plant Spacing for Planters Using Single Seed Metering．Translation of the ASAE，1995,38(2),pp.371～375 [22] E．U．Odigboh．and．C．O．Akubuo ．A two—row automatic cassava cuttings planter：Development、Design and Prototype construction．Journal of Agricultural Engineering Research，Volume 50，September—December．50(1991),pp.13—18． [23] Tao et al., 1995 Y. Tao, C.T. Morrow, P.H. Heinemann and H.J.S. Ill, Fourier based separation technique for shape grading of potatoes using machine vision, Transactions of the ASAE 38 (1995), pp. 949–957. [24] H． Buitenwerf，W．B．Hoogmoed，P．Lerink and J．Müller Assessment of the Behavior of Potato in a Cup—belt Planter．Biosystems Eigineering，95 (2006),35—41． [25]Siecska et al., 1986 J.B. Sieczka, E.E. Ewing and E.D. Markwardt, Potato planter performance and effects on non-uniform spacing, American Potato Journal 63 (1986), pp. 25–37 4 Biosystems Engineering (2006) 95(1), 3541doi:10.1016/j.biosystemseng.2006.06.007PMPower and MachineryAssessment of the Behaviour of Potatoes in a Cup-belt PlanterH. Buitenwerf1,2; W.B. Hoogmoed1; P. Lerink3; J. Mu ller1,41Farm Technology Group, Wageningen University, P.O Box. 17, 6700 AA Wageningen, The Netherlands;e-mail of corresponding author: willem.hoogmoedwur.nl2Krone GmbH, Heinrich-Krone Strasse 10, 48480 Spelle, Germany3IB-Lerink, Laan van Moerkerken 85, 3271AJ Mijnsheerenland, The Netherlands4Institute of Agricultural Engineering, University of Hohenheim, D-70593 Stuttgart, Germany(Received 27 May 2005; accepted in revised form 20 June 2006; published online 2 August 2006)The functioning of most potato planters is based on transport and placement of the seed potatoes by a cup-belt. The capacity of this process is rather low when planting accuracy has to stay at acceptable levels. Themain limitations are set by the speed of the cup-belt and the number and positioning of the cups. It washypothesised 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 a theoretical model wasbuilt. The model calculates the time interval between each successive potato touching the ground. Referring tothe results of the model, two hypotheses were posed, one with respect to the effect of belt speed, and one withrespect to the influence of potato shape. A planter unit was installed in a laboratory to test these twohypotheses. A high-speed camera was used to measure the time interval between each successive potato justbefore they reach the soil surface and to visualise the behaviour of the potato.The results showed that: (a) the higher the speed of the cup-belt, the more uniform is the deposition of thepotatoes; 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 byimproving the design of the cups and its position relative to the duct. This will allow more room for changes inthe cup-belt speeds while keeping a high planting accuracy.r 2006 IAgrE. All rights reservedPublished by Elsevier Ltd1. IntroductionThe cup-belt planter (Fig. 1) is the most commonlyused machine to plant potatoes. The seed potatoes aretransferred from a hopper to the conveyor belt with cupssized to hold one tuber. This belt moves upwards to liftthe potatoes out of the hopper and turns over the uppersheave. At this point, the potatoes fall on the back of thenext cup and are confined in a sheet-metal duct. Atthe bottom, the belt turns over the roller, creating theopening for dropping the potato into a furrow in thesoil.Capacity and accuracy of plant spacing are the mainparameters of machine performance. High accuracy ofplant spacing results in high yield and a uniform sortingof the tubers at harvest (McPhee et al., 1996; Pavek &Thornton, 2003). Field measurements (unpublisheddata) of planting distance in The Netherlands revealeda coefficient of variation (CV) of around 20%. Earlierstudies in Canada and the USA showed even higher CVsof up to 69% (Misener, 1982; Entz & LaCroix, 1983;Sieczka et al., 1986), indicating that the accuracy is lowcompared to precision planters for beet or maize.Travelling speed and accuracy of planting show aninverse correlation. Therefore, the present cup-beltplanters are equipped with two parallel rows of cupsper belt instead of one. Doubling the cup row allowsdouble the travel speed without increasing the belt speedand thus, a higher capacity at the same accuracy isexpected.ARTICLE IN PRESS1537-5110/$32.0035r 2006 IAgrE. All rights reservedPublished by Elsevier LtdThe objective of this study was to investigate thereasons for the low accuracy of cup-belt planters and touse this knowledge to derive recommendations fordesign modifications, e.g. in belt speeds or shape andnumber of cups.For better understanding, a model was developed,describing the potato movement from the moment thepotato enters the duct up to the moment it touches theground. Thus, the behaviour of the potato at the bottomof the soil furrow was not taken into account. Asphysical properties strongly influence the efficiency ofagricultural equipment (Kutzbach, 1989), the shape ofthe potatoes was also considered in the model.Two null hypotheses were formulated: (1) the plantingaccuracy 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. Thehypotheses were tested both theoretically with the modeland empirically in the laboratory.2. Materials and methods2.1. Plant materialSeed potatoes of the cultivars (cv.) Sante, Arinda andMarfona have been used for testing the cup-belt planter,because they show different shape characteristics. Theshape of the potato tuber is an important characteristicfor handling and transporting. Many shape features,usually combined with size measurements, can bedistinguished (Du & Sun, 2004; Tao et al., 1995; Zo dler,1969). In the Netherlands grading of potatoes is mostlydone 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 thetransport processes inside the planter, the length of thepotato is a decisive factor as well.A shape factor S based on all three dimensions wasintroduced:S 100l2wh(1)where l is the length, w the width and h the height of thepotato in mm, with howol. As a reference, alsospherical golf balls (with about the same density aspotatoes), representing a shape factor S of 100 wereused. Shape characteristics of the potatoes used in thisstudy are given in Table 1.2.2. Mathematical model of the processA mathematical model was built to predict plantingaccuracy and planting capacity of the cup-belt planter.The model took into consideration radius and speed ofthe roller, the dimensions and spacing of the cups, theirpositioning with respect to the duct wall and the heightof the planter above the soil surface (Fig. 2). It wasassumed that the potatoes did not move relative to thecup or rotate during their downward movement.The field speed and cup-belt speed can be set toachieve the aimed plant spacing. The frequency fpotofpotatoes leaving the duct at the bottom is calculated asfpotvcxc(2)where vcis the cup-belt speed in ms?1and xcis thedistance in m between the cups on the belt. The angularspeed of the roller orin rad s?1with radius rrin m iscalculated asorvcrr(3)ARTICLE IN PRESS56789104321Fig. 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 levelTable 1Shape characteristics of potato cultivars and golf balls used inthe experimentsCultivarSquare mesh size, mmShape factorSante2835146Arinda3545362Marfona3545168Golf balls42?8100H. BUITENWERF ET AL.36The gap in the duct has to be large enough for a potatoto pass and be released. This gap xreleasein m is reachedat a certain angle areleasein rad of a cup passing theroller. This release angle arelease(Fig. 2) is calculated ascos areleaserc xclear? xreleaserc(4)where: rcis the sum in m of the radius of the roller, thethickness of the belt and the length of the cup; and xclearis the clearance in m between the tip of the cup and thewall of the duct.When the parameters of the potatoes are known, theangle required for releasing a potato can be calculated.Apart from its shape and size, the position of the potatoon the back of the cup is determinative. Therefore, themodel distinguishes two positions: (a) minimum re-quired gap, equal to the height of a potato; and (b)maximum required gap equal to the length of a potato.The time treleasein s needed to form a release angle aois calculated astreleaseareleaseor(5)Calculating treleasefor different potatoes and possiblepositions on the cup yields the deviation from theaverage time interval between consecutive potatoes.Combined with the duration of the free fall and the fieldspeed of the planter, this gives the planting accuracy.When the potato is released, it falls towards the soilsurface. As each potato is released on a unique angularposition, it also has a unique height above the soilsurface at that moment (Fig. 2). A small potato will bereleased earlier and thus at a higher point than a largeone.The model calculates the velocity of the potato justbefore it hits the soil surface uendin ms?1. The initialvertical velocity of the potato u0in m s?1is assumed toequal the vertical component of the track speed of thetip of the cup:v0 rcorcosarelease(6)The release height yreleasein m is calculated asyrelease yr? rcsinarelease(7)where yrin m is the distance between the centre of theroller (line A in Fig. 2) and the soil surface.The time of free fall tfallin s is calculated withyrelease vendtfall 0?5gt2fall(8)where g is the gravitational acceleration (9?8ms?2) andthe final velocity vendis calculated asvend v0 2gyrelease(9)with v0in ms?1being the vertical downward speed ofthe potato at the moment of release.The time for the potato to move from Line A to therelease point treleasehas to be added to tfall.The model calculates the time interval between twoconsecutive potatoes that may be positioned in differentways on the cups. The largest deviations in intervals willoccur when a potato positioned lengthwise is followedby one positioned heightwise, and vice versa.2.3. The laboratory arrangementA standard planter unit (Miedema Hassia SL 4(6)was modified by replacing part of the bottom end of thesheet metal duct with similarly shaped transparentacrylic material (Fig. 3). The cup-belt was driven viathe roller (8 in Fig. 1), by a variable speed electric motor.The speed was measured with an infrared revolutionmeter. Only one row of cups was observed in thisarrangement.A high-speed video camera (SpeedCam Pro, Wein-berger AG, Dietikon, Switzerland) was used to visualisethe behaviour of the potatoes in the transparent ductand to measure the time interval between consecutivepotatoes. A sheet with a coordinate system was placedbehind the opening of the duct, the X axis representingthe ground level. Time was registered when the midpointof a potato passed the ground line. Standard deviationARTICLE IN PRESSxclearrc?release?xreleaseLine ALine CFig. 2. Process simulated by model, simulation starting when thecup crosses line A; release time represents time needed to createan opening sufficiently large for a potato to pass; model alsocalculates time between release of the potato and the moment itreaches the soil surface (free fall); rc, sum of the radius of theroller, thickness of the belt and length of the cup; xclear,clearance between cup and duct wall; xrelease, release clearance;arelease, release angle ; o, angular speed of roller; line C, groundlevel, end of simulationASSESSMENT OF THE BEHAVIOUR OF POTATOES37of the time interval between consecutive potatoes wasused as measure for plant spacing accuracy.For the measurements the camera system was set to arecording rate of 1000 frames per second. With anaverage free fall velocity of 2?5ms?1, the potato movesapprox. 2?5mm between two frames, sufficiently smallto allow an accurate placement registration.The feeding rates for the test of the effect of the speedof the belt were set at 300, 400 and 500 potatoes min?1(fpot 5, 6?7 and 8?3s?1) corresponding to belt speedsof 0?33, 0?45 and 0?56ms?1. These speeds would betypical for belts with 3, 2 and 1 rows of cups,respectively. A fixed feeding rate of 400 potatoes min?1(cup-belt speed of 0?45ms?1) was used to assess theeffect of the potato shape.For the assessment of a normal distribution of thetime intervals, 30 potatoes in five repetitions were used.In the other tests, 20 potatoes in three repetitions wereused.2.4. Statistical analysisThe hypotheses were tested using the Fisher test, asanalysis showed that populations were normally dis-tributed. The one-sided upper tail Fisher test was usedand a was set to 5% representing the probability of atype 1 error, where a true null hypothesis is incorrectlyrejected. The confidence interval is equal to (100?a)%.3. Results and discussion3.1. Cup-belt speed3.1.1. Empirical resultsThe measured time intervals between consecutivepotatoes touching ground showed a normal distribution.Standard deviations s for feeding rates 300, 400 and 500potatoes min?1were 33?0, 20?5 and 12?7ms, respectively.ARTICLE IN PRESSFig. 3. Laboratory test-rig; lower rightpart of the bottom end of the sheet metal duct was replaced with transparent acrylic sheet;upper rightsegment faced by the high-speed cameraH. BUITENWERF ET AL.38According to the F-test the differences between feedingrates were significant. The normal distributions for allthree feeding rates are shown in Fig. 4. The accuracy ofthe planter is increasing with the cup-belt speed, withCVs of 8?6%, 7?1% and 5?5%, respectively.3.1.2. Results predicted by the modelFigure 5 shows the effect of the belt speed on the timeneeded to create a certain opening. A linear relationshipwas found between cup-belt speed and the accuracy ofthe deposition of the potatoes expressed as deviationfrom the time interval. The shorter the time needed forcreating the opening, the smaller the deviations. Resultsof these calculations are given in Table 2.The speed of the cup turning away from the duct wallis important. Instead of a higher belt speed, an increaseof the cups circumferential speed can be achieved bydecreasing the radius of the roller. The radius of theroller used in the test is 0?055m, typical for theseplanters. It was calculated what the radius of the rollerhad to be for lower belt speeds, in order to reach thesame circumferential speed of the tip of the cup as foundfor the highest belt speed. This resulted in a radius of0?025m for 300 potatoes min?1and of 0?041m for 400potatoes min?1. Compared to this outcome, a lineartrend line based on the results of the laboratorymeasurements predicts a maximum performance at aradius of around 0?020m.The mathematical model Eqn (5) predicted a linearrelationship between the radius of the roller (forr40?01m) and the accuracy of the deposition of thepotatoes. The model was used to estimate standarddeviations for different radii at a feeding rate of 300potatoes min?1. The results are given in Fig. 6, showingthat the model predicts a more gradual decrease inaccuracy in comparison with the measured data. Aradius of 0?025m, which is probably the smallest radiustechnically possible, should have given a decrease inARTICLE IN PRESS0.0350.030f (x)0.0250.0200.0150.0100.0050.000180260500340Time x, ms420500 pot min1400 pot min1300 pot min1Fig. 4. Normal distribution of the time interval (x, in ms) ofdeposition of the potatoes (pot) for three feeding rates806448Size of opening, mm321600.000.050.100.15Time, s0.200.250.36 m s10.72 m s10.24 m s1Fig. 5. Effect of belt speed on time needed to create openingTable 2Time intervals between consecutive potatoes calculated by themodel (cv. Marfona)Belt speed,m s?1Difference between shortest and longestinterval, s0?7217?60?3629?40?2442?835302520Standard deviation, ms1510500.000.020.04Radius lower roller, m0.060.08y = 262.21 x 15.497R2 = 0.9987y = 922.1 x 17.597R2 = 0.9995Fig. 6. Relationship between the radius of the roller and thestandard deviation of the time interval of deposition of thepotatoes; the relationship is linear for radii r40?01 m, K,measurement data; m, data from mathematical model; ,extended for ro0?01 m; , linear relationship; R2, coefficient ofdeterminationASSESSMENT OF THE BEHAVIOUR OF POTATOES39standard deviation of about 75% compared to theoriginal radius.3.2. Dimension and shape of the potatoesThe results of the laboratory tests are given in Table 3.It shows the standard deviations of the time interval at afixed feeding rate of 400 potatoes min?1. These resultswere contrary to the expectations that higher standarddeviations 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. Thenormal distribution of the time intervals is shown inFig. 7. Significant differences were found between theballs and the potatoes. No significant differences werefound between the two potato varieties.The poor performance of the balls was caused by thefact that these balls could be positioned in many wayson the back of the cup. Thus, different positions of theballs in adjacent cups resulted in a lower accuracy ofdeposition. The three-dimensional drawing of the cup-belt shows the shape of the gap between cup andduct illustrating that different opening sizes are possible(Fig. 8).Arinda tubers were deposited with a higher accuracythan Marfona tubers. Analysis of the recorded framesand the potatoes, demonstrated that the potatoes of cv.Arinda always were positioned with their longest axisparallel to the back of the cup. Thus, apart from theshape factor, a higher ratio width/height will cause agreater deviation. For cv. Arinda, this ratio was 1?09, forcv. Marfona it was 1?15.3.3. Model versus laboratory test-rigThe mathematical model predicted the performanceof the process under different circumstances. The modelsimulated a better performance for spherical ballscompared to potatoes whereas the laboratory testshowed the opposite. An additional laboratory testwas done to check the reliability of the model.In the model, the time interval between two potatoesis calculated. Starting point is the moment the potatocrosses line A and end point is the crossing of line C(Fig. 2). In the laboratory test-rig the time-intervalbetween potatoes moving from line A to C wasmeasured (Fig. 3). The length, width and height of eachpotato was measured and potatoes were numbered.During the measurement it was determined how eachpotato was positioned on the cup. This position and thepotato dimensions were used as input for the model. Themeasurements were done at a feeding rate of 400potatoes min?1with potatoes of cv. Arinda andMarfona. The standard deviations of the measured timeintervals are shown in Table 4. They were slightlydifferent (higher) from the standard deviations calcu-ARTICLE IN PRESS0.0500.0450.0400.0350.0300.0250.020f (x)0.0150.0100.000245255265275285Time x, ms2953053153253350.005Marfonashape factor 168Arindashape factor 362Golf ball (sphere)shape factor 100Fig. 7. Normal distribution of the time interval (x, in ms) ofdeposition of the potatoes for different shape factors at a fixedfeeding rateFig. 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 itsreleaseTable 3Effect of cultivars on the accuracy of plant spacing; CV,coefficient of variationCultivarStandard deviation, msCV, %Arinda8?603?0Marfona9?923?5Golf balls13?244?6H. BUITENWERF ET AL.40lated by the model. Explanations for these differencesare: (1) the model does not take into considerationsituations as shown in Fig. 8, (2) the passing moment atline A and C was disputable. Oblong potatoes such ascv. Arinda may fall with the tip or with the longest sizedown. This may cause up to 6 ms difference for thepotato to reach the bottom line C.4. ConclusionsThe mathematical model simulating the movement ofthe potatoes at the time of their release from the cup-beltwas a very useful tool leading to the hypotheses to betested and to design the laboratory test-rig.Both the model and the laboratory test showed thatthe higher the speed of the belt, the more uniform thedeposition of the potatoes at zero horizontal velocity.This was due to the fact that the opening, allowing thepotato to drop, is created quicker. This leaves less effectof shape of the potato and the positioning of the potatoon