莲子机械自动去芯自适应定心技术与样机试验
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摘要
针对莲子在自动化去芯过程中的钻偏问题,提出了莲子自适应定心方法,该方法基于一种由曲柄滑块机构与平行四边形机构组合而成的自适应定心装置,能实现去芯钻头位置随莲子大小变化而自动调整。利用随机优化算法对机构中的连杆参数进行了优化,实现去芯钻头轴线保持与莲子轴线同轴,理论定心偏差为0.0448 mm。研制了一种自适应莲子去芯机,进行了未分级莲子的去芯试验,结果表明:自适应莲子去芯机钻正率达91.25%,远高于现有去芯设备,初步验证了自适应定心方法的有效性与实用性。研究结果为莲子优质钻芯设备设计、与莲子形状类似物料的优质钻孔设备研发提供参考。
Lotus seed has very high nutritional and medicinal value, which consists of lotus shell, lotus kernel and lotus core. Because of the bitter taste, the lotus cores need to be removed before eating. The existing equipment for removing core can remove the lotus core fast by operating the coring bit. Before drilling, the lotus kernel has to be centered in the centering working position. The centering device generally consists of two rotating rollers. Under the action of gravity and friction force, the lotus kernel can be centered in the rotating process. However, the position of the coring bit is fixed in the centering working position, and therefore the drilling deviation occurs due to the diameter variation of lotus kernels, and the lotus cores cannot be removed effectively, which lowers the quality of lotus kernels directly. To solve the above problems, the classification process is applied widely. However, it is ineffective owing to the inaccuracy of the classification process and the high requirement for staff and equipment. In order to avoid this situation, the shape parameters of lotus kernels are firstly measured and analyzed in this paper. The results show that the maximum cross section of the lotus kernel is almost round with a mean roundness deviation of 0.46 mm and the diameter ranges from 9 to 16 mm; the average chordwise curvature radius is 7.764 mm, and the average longitudinal curvature radius is 5.177 mm, therefore, the shape of a lotus kernel can approximate to an ellipsoid. Moreover, the centering deviation of the double roller rolling centering method presents a maximum value of 6.654 mm. Aiming at solving the problem of drilling deviation in the automated coring of lotus seeds, this paper proposes a self-adaptive centering method for lotus seeds based on a slider-crank mechanism and a parallel crank mechanism. By utilizing this method, the position of the coring bit can be automatically adjusted according to the lotus kernel size. A mathematical model of self-adaptive centering is established by the complex number vector method. Once the parameters of the linkages are selected, the centering deviation value is determined. For the self-adaptive centering mechanism, the optimization of the linkage parameters is complicated and difficult to meet the demand through traditional optimization methods. Therefore, in order to make the centering deviation minimum, by utilizing the stochastic optimization algorithm of Cuckoo Search, this paper optimizes the linkage parameters in MATLAB. The initial parameters are as follows: the nest number is 25, the probability of detection is 0.25, and the maximum iteration number is 4×105. The optimized parameters of connecting rod are 88.51, 135.72, 0.12828, and 125.35 mm respectively, and the coaxial deviation between the coring bit axis and lotus kernel axis is lower than 0.05 mm. Based on the above study, a self-adaptive machine for removing core of lotus seed was developed and a coring experiment with 400 samples of lotus seeds was carried out. The experimental parameters were as follows: the working cycle was 1.5 s, the roller's rotating speed was 238 r/min, the pressure of the pressing wheel was 25 N, the coring bit diameter was 2.5 mm and the drill speed was 2800 r/min. By measuring the circle run-out value at the maximum cross section of the lotus kernel, the drilling accuracy of lotus seeds were calculated. The results show that the drilling accuracy of a self-adaptive machine for removing core of lotus seed is 91.25%, much higher than that of the existing equipment, which is 60%-70%; moreover, this machine can handle different sizes of lotus kernels. The experimental results verify the effectiveness and practicability of this self-adaptive centering method.
Lotus seed has very high nutritional and medicinal value, which consists of lotus shell, lotus kernel and lotus core. Because of the bitter taste, the lotus cores need to be removed before eating. The existing equipment for removing core can remove the lotus core fast by operating the coring bit. Before drilling, the lotus kernel has to be centered in the centering working position. The centering device generally consists of two rotating rollers. Under the action of gravity and friction force, the lotus kernel can be centered in the rotating process. However, the position of the coring bit is fixed in the centering working position, and therefore the drilling deviation occurs due to the diameter variation of lotus kernels, and the lotus cores cannot be removed effectively, which lowers the quality of lotus kernels directly. To solve the above problems, the classification process is applied widely. However, it is ineffective owing to the inaccuracy of the classification process and the high requirement for staff and equipment. In order to avoid this situation, the shape parameters of lotus kernels are firstly measured and analyzed in this paper. The results show that the maximum cross section of the lotus kernel is almost round with a mean roundness deviation of 0.46 mm and the diameter ranges from 9 to 16 mm; the average chordwise curvature radius is 7.764 mm, and the average longitudinal curvature radius is 5.177 mm, therefore, the shape of a lotus kernel can approximate to an ellipsoid. Moreover, the centering deviation of the double roller rolling centering method presents a maximum value of 6.654 mm. Aiming at solving the problem of drilling deviation in the automated coring of lotus seeds, this paper proposes a self-adaptive centering method for lotus seeds based on a slider-crank mechanism and a parallel crank mechanism. By utilizing this method, the position of the coring bit can be automatically adjusted according to the lotus kernel size. A mathematical model of self-adaptive centering is established by the complex number vector method. Once the parameters of the linkages are selected, the centering deviation value is determined. For the self-adaptive centering mechanism, the optimization of the linkage parameters is complicated and difficult to meet the demand through traditional optimization methods. Therefore, in order to make the centering deviation minimum, by utilizing the stochastic optimization algorithm of Cuckoo Search, this paper optimizes the linkage parameters in MATLAB. The initial parameters are as follows: the nest number is 25, the probability of detection is 0.25, and the maximum iteration number is 4×105. The optimized parameters of connecting rod are 88.51, 135.72, 0.12828, and 125.35 mm respectively, and the coaxial deviation between the coring bit axis and lotus kernel axis is lower than 0.05 mm. Based on the above study, a self-adaptive machine for removing core of lotus seed was developed and a coring experiment with 400 samples of lotus seeds was carried out. The experimental parameters were as follows: the working cycle was 1.5 s, the roller's rotating speed was 238 r/min, the pressure of the pressing wheel was 25 N, the coring bit diameter was 2.5 mm and the drill speed was 2800 r/min. By measuring the circle run-out value at the maximum cross section of the lotus kernel, the drilling accuracy of lotus seeds were calculated. The results show that the drilling accuracy of a self-adaptive machine for removing core of lotus seed is 91.25%, much higher than that of the existing equipment, which is 60%-70%; moreover, this machine can handle different sizes of lotus kernels. The experimental results verify the effectiveness and practicability of this self-adaptive centering method.
引文
[1]郑宝东.中国莲子(Nympheaceae Nelumbo Adans)种质资源主要品质的研究与应用[D].福建:福建农林大学,2004.Zheng Baodong.The Research and Application of Chinese Lotus-Seed(Nympheaceae Nelumbo Adans)Germplasm Resources[D].Fujian:Fujian Agriculture and Forestry University,2004.(in Chinese with English abstract)
[2]Xie Lijuan,Zong Li,Li Xiaoyu.Experimental study onmechanical properties of lotus seed[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2005,21(7):11-14.
[3]郑宝东,曾绍校,李怡彬,等.莲子淀粉品质对莲子汁流变特性和保质期影响的研究[J].农业工程学报,2005,21(12):167-170.Zheng Baodong,Zeng Shaoxiao,Li Yibin,et al.Effect of lotus-seed starch quality on lotus-seed juice rheological property and shelf life[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2005,21(12):167-170.(in Chinese with English abstract)
[4]Zeng Hongyan,Cai Lianhui,Cai Xiling.Amino acid profiles and quality from lotus seed proteins[J].Journal of the Science of Food and Agriculture,2013,93(5):1070-1075.
[5]张羽,郑铁松,陈静.莲子蛋白质提取工艺研究[J].食品科学,2007,28(9):144-147.Zhang Yu,Zheng Tiesong,Chen Jing.Study on protein extraction technology from lotus seed[J].Food Science,2007,28(9):144-147.(in Chinese with English abstract)
[6]曾绍校.莲子淀粉品质特性的研究与应用[D].福州:福建农林大学,2007.Zeng Shaoxiao.Studies on Qualitative Characteristics of Lotus-Seed(Nelumbo nueifera Gaertn)Starch and its Application[D].Fuzhou:Fujian Agriculture and Forestry University,2007.(in Chinese with English abstract)
[7]郑宝东,郑金贵,曾绍校.我国主要莲子品种营养成分的分析[J].营养学报,2003,25(2):153-156.Zheng Baodong,Zheng Jingui,Zeng Shaoxiao.Analysis of the nutritional composition in chinese main lotus seed varieties[J].Acta Nutrimenta Sinica,2003,25(2):153-156.(in Chinese with English abstract)
[8]张永林,易启伟,余群,等.多联辊刀式莲子剥壳机的结构与工作原理[J].农业工程学报,2008,24(12):76-79.Zhang Yonglin,Yi Qiwei,Yu Qun,et al.Structure and working principle of de-huller with multiple cutter units for lotus seeds[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2008,24(12):76-79.(in Chinese with English abstract)
[9]邹晓丹.莲子剥壳机研究现状[J].机电技术,2013(1):158-160.Zou Xiaodan.Research status of Lotus Seed shelling[J].Mechanical and Electrical Technology,2013(1):158-160.(in Chinese with English abstract)
[10]徐谐庆,饶洪辉,李涛,等.全自动莲子剥壳去皮机的设计与试验[J].农业工程学报,2014,30(13):28-34.Xu Xieqing,Rao Honghui,Li Tao,et al.Design and experiment on automatic husking and peeling machine for lotus seeds[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2014,30(13):28-34.(in Chinese with English abstract)
[11]裴圣华,饶洪辉,刘木华.莲子通芯机研究现状与展望[J].中国农机化学报,2013,34(6):43-45.Pei Shenghua,Rao Honghui,Liu Muhua.Research status and prospect of machine for the coring of lotus seed[J].Journal of Chinese Agricultural Mechanization,2013,34(6):43-45.(in Chinese with English abstract)
[12]童艺成.全自动莲子钻芯机:中国专利,200620051704.2[P].2007-08-01.Tong Yicheng.Automatic Machine of Lotus Seed Drilling:China Patent,200620051704.2[P].2007-08-01.(in Chinese with English abstract)
[13]马秋成,黄伟华,王凌川,等.全自动莲子去芯机:中国专利,200910251231.9[P].2009-12-02.
[14]万伟红,吴鹏辉,苏志伟,等.莲子分级剥壳技术与设备研究进展[J].农机化研究,2014(11):42-45.Wan Weihong,Wu Penghui,Su Zhiwei,et al.Investigation progress of process and equipment in lotus seed grading,shelling and dislodge core[J].Journal of Agricultural Mechanization Research,2014(11):42-45.(in Chinese with English abstract)
[15]杜铮,宗力.莲子分级设备的研究与应用现状分析[J].湖北农业科学,2009,48(4):979-981.Du Zheng,Zong Li.Current studies and applications on grader of lotus seeds[J].Hubei Agricultural Sciences,2009,48(4):979-981.(in Chinese with English abstract)
[16]杜铮,宗力.干壳莲子螺杆分级机设计与分级试验[J].农机化研究,2009,31(9):117-119.Du Zheng,Zong Li.Design and experiment of a screw for granding of lotus seed[J].Agriculture Mechanization Research,2009,31(9):117-119.(in Chinese with English abstract)
[17]张永林,王旺平,余群,等.小型莲子穿心机:中国专利,201210151402.2[P].2012-05-16.
[18]薛玉君,畅为航,雷贤卿,等.圆度误差评定的研究与展望[J].机床与液压,2008,36(12):183-185.Xue Yujun,Chang Weihang,Lei Xianqing,et al.Research and advances about evaluation of roundness error[J].Machine tool and Hydraulics,2008,36(12):183-185.(in Chinese with English abstract)
[19]曾绍校,张怡,梁静,等.中国22个莲子品种外观品质和淀粉品质的研究[J].中国食品学报,2007,7(1):74-78.Zeng Shaoxiao,Zhang Yi,Liang Jing,et al.Studies on appearance quality and starch quality of 22 kinds of lotus-seed[J].Journal of Chinese Institute of Food science and Technology,2007,7(1):74-78.(in Chinese with English abstract)
[20]孙桓,陈作模,葛文杰.机械原理[M].北京:高等教育出版社,2010:37-38.
[21]Kennedy J,Eberhart R,Li Xiaoyu.Particle Swarm Optimization[C]//IEEE int.Conf.on Neural Networks,Perth,Australia,1995:1942-1948.
[22]Yang X S,Deb S.Engineering optimization by cuckoo search[J].International Journal of Mathematical Modelling and Numerical Optimisation,2010,1(4):330-343.
[23]李煜,马良.新型元启发式布谷鸟搜索算法[J].系统工程,2012,30(8):64-69.Li Yu,Ma Liang.A new metaheuristic cuckoo search algorithm[J].Systems Engineering,2012,30(8):64-69.(in Chinese with English abstract)
[24]刘守祥,杨友平,张善彪,等.6CB-5.4型莲籽穿芯脱壳机的研究[J].食品与机械,2003(4):23-25.Liu Shouxiang,Yang Youping,Zhang Shanbiao,et al.Research on the automatic machine of the lotus seedsdrilling and peeling[J].Food and Machinery,2003(4):23-25 .(in Chinese with English abstract)
[2]Xie Lijuan,Zong Li,Li Xiaoyu.Experimental study onmechanical properties of lotus seed[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2005,21(7):11-14.
[3]郑宝东,曾绍校,李怡彬,等.莲子淀粉品质对莲子汁流变特性和保质期影响的研究[J].农业工程学报,2005,21(12):167-170.Zheng Baodong,Zeng Shaoxiao,Li Yibin,et al.Effect of lotus-seed starch quality on lotus-seed juice rheological property and shelf life[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2005,21(12):167-170.(in Chinese with English abstract)
[4]Zeng Hongyan,Cai Lianhui,Cai Xiling.Amino acid profiles and quality from lotus seed proteins[J].Journal of the Science of Food and Agriculture,2013,93(5):1070-1075.
[5]张羽,郑铁松,陈静.莲子蛋白质提取工艺研究[J].食品科学,2007,28(9):144-147.Zhang Yu,Zheng Tiesong,Chen Jing.Study on protein extraction technology from lotus seed[J].Food Science,2007,28(9):144-147.(in Chinese with English abstract)
[6]曾绍校.莲子淀粉品质特性的研究与应用[D].福州:福建农林大学,2007.Zeng Shaoxiao.Studies on Qualitative Characteristics of Lotus-Seed(Nelumbo nueifera Gaertn)Starch and its Application[D].Fuzhou:Fujian Agriculture and Forestry University,2007.(in Chinese with English abstract)
[7]郑宝东,郑金贵,曾绍校.我国主要莲子品种营养成分的分析[J].营养学报,2003,25(2):153-156.Zheng Baodong,Zheng Jingui,Zeng Shaoxiao.Analysis of the nutritional composition in chinese main lotus seed varieties[J].Acta Nutrimenta Sinica,2003,25(2):153-156.(in Chinese with English abstract)
[8]张永林,易启伟,余群,等.多联辊刀式莲子剥壳机的结构与工作原理[J].农业工程学报,2008,24(12):76-79.Zhang Yonglin,Yi Qiwei,Yu Qun,et al.Structure and working principle of de-huller with multiple cutter units for lotus seeds[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2008,24(12):76-79.(in Chinese with English abstract)
[9]邹晓丹.莲子剥壳机研究现状[J].机电技术,2013(1):158-160.Zou Xiaodan.Research status of Lotus Seed shelling[J].Mechanical and Electrical Technology,2013(1):158-160.(in Chinese with English abstract)
[10]徐谐庆,饶洪辉,李涛,等.全自动莲子剥壳去皮机的设计与试验[J].农业工程学报,2014,30(13):28-34.Xu Xieqing,Rao Honghui,Li Tao,et al.Design and experiment on automatic husking and peeling machine for lotus seeds[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2014,30(13):28-34.(in Chinese with English abstract)
[11]裴圣华,饶洪辉,刘木华.莲子通芯机研究现状与展望[J].中国农机化学报,2013,34(6):43-45.Pei Shenghua,Rao Honghui,Liu Muhua.Research status and prospect of machine for the coring of lotus seed[J].Journal of Chinese Agricultural Mechanization,2013,34(6):43-45.(in Chinese with English abstract)
[12]童艺成.全自动莲子钻芯机:中国专利,200620051704.2[P].2007-08-01.Tong Yicheng.Automatic Machine of Lotus Seed Drilling:China Patent,200620051704.2[P].2007-08-01.(in Chinese with English abstract)
[13]马秋成,黄伟华,王凌川,等.全自动莲子去芯机:中国专利,200910251231.9[P].2009-12-02.
[14]万伟红,吴鹏辉,苏志伟,等.莲子分级剥壳技术与设备研究进展[J].农机化研究,2014(11):42-45.Wan Weihong,Wu Penghui,Su Zhiwei,et al.Investigation progress of process and equipment in lotus seed grading,shelling and dislodge core[J].Journal of Agricultural Mechanization Research,2014(11):42-45.(in Chinese with English abstract)
[15]杜铮,宗力.莲子分级设备的研究与应用现状分析[J].湖北农业科学,2009,48(4):979-981.Du Zheng,Zong Li.Current studies and applications on grader of lotus seeds[J].Hubei Agricultural Sciences,2009,48(4):979-981.(in Chinese with English abstract)
[16]杜铮,宗力.干壳莲子螺杆分级机设计与分级试验[J].农机化研究,2009,31(9):117-119.Du Zheng,Zong Li.Design and experiment of a screw for granding of lotus seed[J].Agriculture Mechanization Research,2009,31(9):117-119.(in Chinese with English abstract)
[17]张永林,王旺平,余群,等.小型莲子穿心机:中国专利,201210151402.2[P].2012-05-16.
[18]薛玉君,畅为航,雷贤卿,等.圆度误差评定的研究与展望[J].机床与液压,2008,36(12):183-185.Xue Yujun,Chang Weihang,Lei Xianqing,et al.Research and advances about evaluation of roundness error[J].Machine tool and Hydraulics,2008,36(12):183-185.(in Chinese with English abstract)
[19]曾绍校,张怡,梁静,等.中国22个莲子品种外观品质和淀粉品质的研究[J].中国食品学报,2007,7(1):74-78.Zeng Shaoxiao,Zhang Yi,Liang Jing,et al.Studies on appearance quality and starch quality of 22 kinds of lotus-seed[J].Journal of Chinese Institute of Food science and Technology,2007,7(1):74-78.(in Chinese with English abstract)
[20]孙桓,陈作模,葛文杰.机械原理[M].北京:高等教育出版社,2010:37-38.
[21]Kennedy J,Eberhart R,Li Xiaoyu.Particle Swarm Optimization[C]//IEEE int.Conf.on Neural Networks,Perth,Australia,1995:1942-1948.
[22]Yang X S,Deb S.Engineering optimization by cuckoo search[J].International Journal of Mathematical Modelling and Numerical Optimisation,2010,1(4):330-343.
[23]李煜,马良.新型元启发式布谷鸟搜索算法[J].系统工程,2012,30(8):64-69.Li Yu,Ma Liang.A new metaheuristic cuckoo search algorithm[J].Systems Engineering,2012,30(8):64-69.(in Chinese with English abstract)
[24]刘守祥,杨友平,张善彪,等.6CB-5.4型莲籽穿芯脱壳机的研究[J].食品与机械,2003(4):23-25.Liu Shouxiang,Yang Youping,Zhang Shanbiao,et al.Research on the automatic machine of the lotus seedsdrilling and peeling[J].Food and Machinery,2003(4):23-25 .(in Chinese with English abstract)