資源目錄里展示的全都有，所見(jiàn)即所得。下載后全都有,請(qǐng)放心下載。原稿可自行編輯修改=【QQ：401339828 或11970985 有疑問(wèn)可加】 Mathematical and Computer Modelling 58 (2013) 684690Contents lists available at SciVerse ScienceDirectMathematical and Computer Modellingjournal homepage: of a whole-feeding and automatic rice thresher forsingle plantChenglong Huang, Lingfeng Duan, Qian Liu, Wanneng YangBritton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology,1037 Luoyu Rd., Wuhan 430074, PR ChinaKey Laboratory of Biomedical Photonics of Ministry of Education, Huazhong University of Science and Technology, 1037 Luoyu Rd., Wuhan 430074, PR Chinaa r t i c l ei n f oArticle history:Received 28 September 2011Accepted 26 October 2011Keywords:Single-plant paddy thresherWhole-feedingHierarchical multi-rollers threshingFish scale sieve plateHigh-precision and automationa b s t r a c tThreshing is an essential pretreatment in rice yield-related traits evaluation and ricethresher is an important study of agricultural machinery automation. However, traditionalthreshers aim at threshing filled grains with simple function, which are inapplicable tohigh-precision and automatic yield-related traits evaluation of rice. And the conventionalthreshing method for the traits evaluation is still manual. To improve it, we developeda whole-feeding and automatic rice thresher for single plant. The thresher adopted ahierarchical multi-roller rolling method to thresh filled and unfilled grains respectively.A fish scale sieve plate was designed to separate the grains from the straw and the wholesystem was controlled by Programmable Logic Controller (PLC) automatically. To evaluatethe threshing system, two batches of rice plants were tested, and the results showed thatthe thresher had the advantages of high precision, low breakage and no residue. Thus,the thresher provides strong support for high-precision and automatic yield-related traitsevaluation of rice.2011 Elsevier Ltd. All rights reserved.1. IntroductionRice is one of the staple foods in the world and approximately half of the world population feed on it 1. The aim ofrice breeding is always to increase rice yield 2. Yield-related traits of rice, such as total spikelet number per plant, filledspikelet number per plant, seed-setting rate, thousand kernel weight, grain length and grain width, directly determine itsproduction 3. However, in order to evaluate the aforementioned traits, threshing is an essential pretreatment. Therefore,it is significant to study on the rice thresher.Since the machine-vision technique is widely used in agriculture 4,5, more and more automated instruments areactualizedforthetraitsevaluationwiththericesamplesthreshedpreviously6.Itisobviousthattheprocedureofthreshinglimits the automation and the efficiency of rice traits evaluation to a large degree. Therefore, in order to achieve the purpose,a type of rice thresher with the features of whole-feeding, no residue, and automation is really needed.Existing paddy threshers for single plant were used to thresh filled grains, the function of which was too simple to servethe needs of high-precision and automatic traits evaluation. Due to the connectivity-force difference between grains andstraw,mostofthesingleplantthresherswerehalf-feedingandsemiautomatic7.Althoughagreatdealofresearchwasdoneto improve it, the threshing precision and automation were still the vital problems. In practice, the conventional threshingmethod for rice yield-related traits evaluation is still manual. Therefore, a single plant thresher designed for high-precisionand automatic traits evaluation is really desirable.This work was supported the Key Program of the Natural Science Foundation of Hubei Province (Grant No. 2008CDA087).Corresponding author at: Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for OptoelectronicsHuazhong University ofScience and Technology, 1037 Luoyu Rd., Wuhan 430074, PR China. Tel.: +86 27 8779 2033; fax: +86 27 8779 2034.E-mail address: (W. Yang).0895-7177/$ see front matter2011 Elsevier Ltd. All rights reserved.doi:10.1016/j.mcm.2011.10.033C. Huang et al. / Mathematical and Computer Modelling 58 (2013) 684690685Fig. 1. The schematic drawing of whole-feeding and automatic rice thresher.Fig. 2. The prototype (A) and the running results (B) of the whole-feeding and automatic rice thresher.To achieve it, we designed a hierarchical multi-rollers threshing unit, which could detach filled and unfilled grains fromstraw with high-precision and this threshing method was applicable to different rice varieties. Moreover, fish scale sieveplate was firstly adopted in single plant thresher and was used to separate the grains from the straw effectively. In addition,the technology of industrial control was applied to realize paddy threshing automation. The objective of this work was tointroduce a new kind of single plant rice thresher, which would be widely used in rice yield-related traits evaluation andgreatly promote the evaluation efficiency.2. Materials and methods2.1. Whole-feeding and automatic rice thresherThe schematic drawing of the thresher is designed as Fig. 1, consisting of photoelectric switch, panicle conveyor, filledgrain threshing unit, unfilled grain threshing unit, feed plate, centrifugal fan, fish scale sieve plate, vibrating screen unit anda programmable logic controller (PLC, CP1H-Y20DT-D, Omron, Japan).The prototype of the whole-feeding and automatic thresher is shown in Fig. 2A and the running results of the thresherare shown in the Fig. 2B. The panicle samples Fig. 2B(a) were put on the conveyor in sequence, and the panicles weretransmittedintothethresher.Thenthefilledgrainthreshingunitthreshedthefilledgrains,whichweresenttothefishscalesieve plate through the feed plate. And the unfilled threshing unit threshed unfilled grains. The unfilled grains and strawweretransmittedtothefishscalesieveplatetoo.Next,thevibratingscreenunitworkedincollaborationwithcentrifugalfanto separate the straw and grains. Finally, the grains Fig. 2B(b) and straw Fig. 2B(c) exited at different places respectively.686C. Huang et al. / Mathematical and Computer Modelling 58 (2013) 684690Fig. 3. Details of the threshing unit.Fig. 4. The cam vibration mechanism.2.2. Threshing unitAlthough various threshing mechanism were developed, such as axial flow rice thresher 8, and double roller ricethresher, the problem of breakage and separation are serious to satisfy high precision and automatic traits evaluation 9.To improve it, we developed a new kind of threshing unit, the details of which are shown as Fig. 3. The dentate conveyor rantodrivethedentateroller,andtheyworkedincollaborationtothreshgrains.Inaddition,thepressurebetweentheconveyorand the roller was able to be regulated by adjusting the screw. The threshing unit was generally divided into two stages:filled grain threshing unit and unfilled grain threshing unit. And the pressure in unfilled grain threshing unit was greaterthan that in filled grain threshing unit. Therefore, this method was able to thresh the grains with high precision and lowbreakage. Moreover, the thresher was applicable to various rice varieties by adjusting the screw properly.2.3. Sieving unitThe sieving unit in the thresher adopted a kind of cam vibration mechanism, which is shown in Fig. 4. The cam rotated todrive the sieve plate vibratory through the roller wheel and link rod. Besides, it was worth mentioning that the sieve platewas specially designed for grains screening and the holes in the sieve plate were like fish scales, which was shown in Fig. 5.2.4. System controlThe work flowchart of the rice thresher is shown in Fig. 6. The whole working process was controlled by PLC. Thus thethresher was able to thresh the paddy and screen the grains automatically. And the workflow of the thresher includedfollowing steps:(1) Putting the panicles per plant onto the conveyor in a sequence.(2) The photoelectric switch sensing, and the controller deciding whether the photoelectric switch effective. If true, PLCdisabled the photoelectric switch. If not, PLC did not act and the workflow went to step (5).(3) PLC started threshing unit.(4) PLC started vibrating unit and centrifugal fan, and they worked in collaboration.(5) If the whole plant finished threshing, the next plant began. If not, going to step (1).C. Huang et al. / Mathematical and Computer Modelling 58 (2013) 684690687(a) 3D rendering of fish scale sieve plate.(b) Details of fish scale holes.Fig. 5. Design of the fish scale sieve plate.3. ResultsIn order to evaluate the thresher performance, two batches of rice plants (Zhonghua 11, Huageng 295) were tested. Andtheplantnumberswere101and71,respectively.Beforetested,thericeplantsweredriedupinthesunandthenthepanicleswere cut from the plants. And the filled grains, unfilled grains, and broken grains in the straw exit and grains exit p werecounted for each plants, respectively.The threshing results are shown in Fig. 7. The results of threshing loss, filled grains, unfilled grains and broken grains forZhonghua 11 and Huageng 295 were listed in the figure, respectively.ATLP=1nNi=1xlixti(1)ABGP=1nNi=1xbixti(2)ATLPfg=1nNi=1xflixfti(3)ATLPug=1nNi=1xulixuti(4)where the parameters of xli,xti,xbi,xfli,xfti,xuliand xutirepresent threshing loss number, total grains number, broken grainsnumber, filled grains lost number, filled grains total number, unfilled grains lost number, and unfilled grains total number,respectively.The result analysis for the two of rice plants is listed in the Table 1. The Average Threshing Loss Percent (ATLP), definedby Eq. (1) and Average Broken Grains Percent (ABGP) defined by Eq. (2) for Zhonghua 11 were 4.07% and 3.16%, respectively.And the ATLP and ABGP for Huageng 295 were 4.80% and 3.60%, respectively. And the Average Threshing Loss Percent forFilled Grains (ATLPfg) defined by Eq. (3) and Average Threshing Loss Percent for Unfilled Grains (ATLPug) defined by Eq. (4),were 2.30% and 6.55% for Zhonghua 11, 2.77% and 9.70% for Huageng 295, respectively.688C. Huang et al. / Mathematical and Computer Modelling 58 (2013) 684690Fig. 6. The work flowchart of the rice thresher.Table 1The results analysis for threshing errors.Rice varietyPlant numberABGP (%)ATLP (%)ATLPfg(%)ATLPug(%)Zhonghua 111013.164.072.306.55Huageng 295713.604.802.779.704. Discussions4.1. High precision threshing systemThe results proved that the thresher generally performed high threshing precision, due to the specifically designedthreshing device, in which the threshing units for filled and unfilled grains were separated and the different grains could bethreshedrespectivelywithhighprecision.Anditwasalsodemonstratedthattheunfilledgrainsweremoredifficulttothreshthanfilledgrainsduetotheircharacteristicsdifference.Theoreticallygrainswereabletobethreshedexactlybyadjustingthescrew properly, but the threshing loss and damaged grains were unavoidable in practice. And the threshing loss or threshingbreakage was able to be improved by adjusting the screw, but the threshing loss decrease probably increased the threshingbreakage. And it was believed the threshing system had an optimum threshing effect on filled grains than unfilled grains,because of the connectivity-force difference between grains and straw. In addition, the experiments also showed that therewas no threshing residue in the system, which was crucial to prevent interference for single plant rice traits evaluation.4.2. High separation threshing system with no residuesThe results proved that the thresher generally performed high separation precision, due to the specifically designedthreshing sieving unit, in which the fish scale sieve plate was adopted. In addition, centrifugal fan worked with the sievingunit in collaboration to eliminate the threshing residues. The experiments also showed that there was no threshing residuein the system, which was crucial to prevent interference for single plant rice traits evaluation.C. Huang et al. / Mathematical and Computer Modelling 58 (2013) 684690689Fig. 7. The threshing results of rice (a) Zhonghua 11 and (b) Huageng 295.4.3. Automatically threshing systemThe entire threshing process was controlled by the PLC and the thresher ran automatically. Generally, it took about 20 sforthethreshertofinishariceplantautomatically,whichwouldpromotethedevelopmentforautomatictraitsevaluationofrice. Although the rice thresher realized the function of high precision and automatic threshing, a proper pressure betweenthe conveyor and the roller needed to be obtained for each rice variety by adjusting the screw before threshing. And theprocess was time consuming and tedious. In future, the thresher should be adaptive to different rice varieties automatically,which could be achieved by setting fixed pressure stages for different varieties.5. ConclusionThispaperdemonstratedawholefeedingandautomaticricethresherforsingleplant.Thethresheradoptedahierarchicalmulti-rollersthreshingunitandfishscalesievingunittoachievehighprecisionthreshing.Andtheprogrammablecontrollertechnique was applied to automate the whole threshing. The results proved that the thresher had the advantages of highthreshing-precision, low breakage and no residue. In conclusion, this work provides a novel threshing device for high-precision and automatic rice yield-related traits evaluation.AcknowledgmentsWe deeply appreciated the help from Huazhong Agricultural University for providing sufficient rice plants. This workwas supported by the Key Program of the Natural Science Foundation of Hubei Province (Grant No. 2008CDA087).690C. Huang et al. / Mathematical and Computer Modelling 58 (2013) 684690References1 Jinyan Zhu, Yong Zhou, Yanhua Liu, et al., Fine mapping of a major QTL controlling panicle number in rice, Mol Breed 27 (2011) 171180.2 Qifa Zhang, Strategies for developing green super rice, Proceedings of the National Academy of Sciences of the United States of America 104 (42) (2007)1640216409.3 Yongzhong Xing, Qifa Zhang, Genetic and molecular bases of rice yield, Annual Review of Plant Biology 61 (2010) 11.111.22.4 G. Venora, O.Grillo, R. 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