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QUADRATIC OPTIMIZATION METHOD AND ITS APPLICATION ON OPTIMIZING MECHANISM PARAMETER

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Chinese Journal of Mechanical Engineering 2006年第4期19卷 519-523页

作者： ZHAO yun CHEN Jianneng yu Yaxin yu gaohong ZHU Jianping College of Mechanical Engineering and Automation Zhejiang Sci-Tech University Hangzhou 310018 China College of Biosystem Engineering and Food Science Zhejiang University Hangzhou 310029 China Modem Agricultural EquipmentHuzhou Combine Harvester Co. Ltd Huzhou 313000 China

In order that the mechanism designed meets the requirements of kinematics with optimal dynamics behaviors, a quadratic optimization method is proposed based on the different characteristics of kinematic and dynamic optimization. This method includes two steps of optimization, that is, kinematic and dynamic optimization. Meanwhile, it uses the results of the kinematic optimization as the constraint equations of dynamic optimization. This method is used in the parameters optimization of transplanting mechanism with elliptic planetary gears of high-speed rice seedling transplanter with remarkable significance. The parameters spectrum, which meets to the kinematic requirements, is obtained through visualized human-computer interactions in the kinematics optimization, and the optimal parameters are obtained based on improved genetic algorithm in dynamic optimization. In the dynamic optimization, the objective function is chosen as the optimal＇ dynamic behavior and the constraint equations are from the results of the kinematic optimization, This method is suitable for multi-objective optimization when both the kinematic and dynamic performances act as objective functions.

关键词： Quadratic optimization Parameter optimization Kinematics Dynamics

取秧侧向零偏移的空间轨迹再生稻分插机构设计与试验

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农业机械学报 2024年第2期55卷 101-108页

作者：孙良姜凯雯周斌俞高红崔荣江薛向磊浙江理工大学机械工程学院杭州310018 浙江省种植装备技术重点实验室杭州310018 杭州职业技术学院杭州310018 浙江省农业科学院杭州310018 农业农村部东南丘陵山地农业装备重点实验室杭州310018

为了解决现有空间行星轮系式分插机构在再生稻宽窄行机械化种植取秧过程中出现侧向偏移量和侧向偏转角的技术难题,本文提出一种具有局部平面轨迹特性的空间轨迹不等速行星轮系机构,并开展基于取秧口和机构回转中心位置约束下的宽窄行分... 详细信息

为了解决现有空间行星轮系式分插机构在再生稻宽窄行机械化种植取秧过程中出现侧向偏移量和侧向偏转角的技术难题,本文提出一种具有局部平面轨迹特性的空间轨迹不等速行星轮系机构,并开展基于取秧口和机构回转中心位置约束下的宽窄行分插机构综合研究。构建了基于关键位姿点(取秧起始点、取秧结束点、推秧点)的空间轮系机构运动综合模型,利用关键位姿点求解机构杆长参数与空间交错轴信息,并通过优选二杆相对角位移参数实现机构传动比分配。将不完全非圆齿轮副引入空间行星轮系机构,利用间歇机构锁止弧约束行星轴,实现机构取秧过程侧向零偏移量、侧向零偏转角的平面轨迹段。通过仿真分析与机构样机试验验证了机构实际作业性能与理论设计相一致,结果表明:分插机构取秧侧向零偏移量,取秧侧向零偏转角,推秧侧向总偏移量为50.24 mm、取秧角为5.18°、推秧角为71.56°、推秧侧向角为16.26°、插秧穴口宽度为22.43 mm、轨迹高度为289.76 mm,满足预期设计要求。最后通过田间试验验证,分插机构可实现等行距取秧口和既定机构回转中心下宽行(40 cm)与窄行(20 cm)间隔机插,满足再生稻宽窄行种植要求。

关键词：再生稻分插机构零偏移量零偏角宽窄行不完全非圆齿轮系

Optimization design and test of rice plug seedling transplanting mechanism of planetary gear train with incomplete eccentric circular gear and non-circular gears

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International Journal of Agricultural and Biological Engineering 2017年第6期10卷 43-55页

作者： Ye Bingliang Yi Weiming yu gaohong Gao Yang Zhao Xiong Faculty of Mechanical Engineering and Automation Zhejiang Sci-Tech UniversityHangzhou 310018China Zhejiang Province Key Laboratory of Transplanting Equipment and Technology Hangzhou 310018China

In order to solve the problem of the high-speed mechanized transplanting of rice plug seedlings,the design requirements of transplanting mechanism for rice plug seedlings were analyzed and a kind of rice plug seedling transplanting mechanism of planetary gear train based on the drive with incomplete eccentric circular gear and non-circular gears was designed innovatively.The laboratory kinematics was examined.The working principle of the transplanting mechanism for rice plug seedlings was studied,kinematics analysis of the transplanting mechanism was carried out and its kinematic model was set up.A human-computer interaction optimization method was used to optimize the parameters of the transplanting mechanism.The computer aided analysis and optimization software of the transplanting mechanism based on Visual Basic 6.0 was developed.Through analyzing the influence of design variables on the optimization objectives of the transplanting mechanism,a set of parameters of the transplanting mechanism which meet the requirements of transplanting trajectory and posture for transplanting rice seedlings were obtained by means of human-computer interaction.The structure of the transplanting mechanism was designed according to this set of parameters,and its virtual prototype and physical prototype were set up and manufactured,respectively.The kinematic simulation test and high-speed photography kinematic test of the transplanting mechanism were conducted to obtain its kinematic performances,such as transplanting trajectory and posture.The results of bench test,simulation analysis and theoretical analysis were almost in agreement,which verified the correctness of the theoretical model and design results of the transplanting mechanism,indicating that the optimized transplanting mechanism can satisfy the requirements of transplanting rice seedlings and be applied in the rice plug seedling transplanter.

关键词： plug seedling transplanting mechanism incomplete eccentric circular gear non-circular gear planetary gear train optimization design

改进DeepLabV3+算法提取无作物田垄导航线

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农业工程学报 2024年第10期40卷 168-175页

作者：俞高红王一淼甘帅汇徐惠民陈逸津王磊浙江理工大学机械工程学院杭州310018 浙江省种植装备技术重点实验室杭州310018

机器视觉导航是智慧农业的重要部分,无作物田垄的导航线检测是旱地移栽导航的关键。针对无作物田垄颜色信息相近、纹理差距小,传统图像处理方法适用性差、准确率低,语义分割算法检测速度慢、实时性差的问题,该研究提出一种基于改进DeepL... 详细信息

机器视觉导航是智慧农业的重要部分,无作物田垄的导航线检测是旱地移栽导航的关键。针对无作物田垄颜色信息相近、纹理差距小,传统图像处理方法适用性差、准确率低,语义分割算法检测速度慢、实时性差的问题,该研究提出一种基于改进DeepLabV3+的田垄分割模型。首先对传统DeepLabV3+网络进行轻量化设计,用MobileNetV2网络代替主干网络Xception,以提高算法的检测速度和实时性;接着引入CBAM(convolutional block attention module,CBAM)注意力机制,使模型能够更好地处理垄面边界信息;然后利用垄面边界信息获得导航特征点,对于断垄情况,导航特征点会出现偏差,因此利用四分位数对导航特征点异常值进行筛选,并采用最小二乘法进行导航线拟合。模型评估结果显示,改进后模型的平均像素精确度和平均交并比分别为96.27%和93.18%,平均检测帧率为84.21帧/s,优于PSPNet、U-Net、HRNet、Segformer以及DeepLabV3+网络。在不同田垄环境下,最大角度误差为1.2°,最大像素误差为9,能够有效从不同场景中获取导航线。研究结果可为农业机器人的无作物田垄导航提供参考。

关键词：机器视觉导航语义分割导航路径最小二乘法无作物田垄

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青菜高密度移栽机植苗机构的设计与试验

浙江理工大学学报（自然科学版） 2024年第1期51卷 100-111页

作者：鲍李旭俞高红赵雄王磊浙江理工大学机械工程学院杭州310018 浙江理工大学浙江省种植装备技术重点实验室杭州310018

目前国内移栽机尚无成熟的适用于青菜等多行密植蔬菜移栽的植苗机构;针对小株距小行距、高效率的密植移栽要求,设计了一种非圆齿轮行星轮系八行同步植苗机构,并进行了运动学仿真和田间移栽试验。对非圆齿轮行星轮系进行了运动学建模与分... 详细信息

目前国内移栽机尚无成熟的适用于青菜等多行密植蔬菜移栽的植苗机构;针对小株距小行距、高效率的密植移栽要求,设计了一种非圆齿轮行星轮系八行同步植苗机构,并进行了运动学仿真和田间移栽试验。对非圆齿轮行星轮系进行了运动学建模与分析,开发了植苗机构辅助分析与优化设计软件;分析了不同机构参数对植苗轨迹姿态的影响,并通过人机交互的方式得到一组满足青菜小株距移栽要求的机构参数;建立了八行同步植苗机构的三维模型,利用虚拟样机仿真技术绘制出仿真轨迹,并与理论轨迹进行对比,以验证植苗机构三维设计的正确性;开展了田间移栽试验,以验证该机构的可行性和实用性。试验结果表明:在作业转速为15r/min、前进速度为55mm/s的情况下,八行植苗机构的作业株距和行距均为110mm,平均植苗成功率为93.9%,移栽密度超过70株/m2,试验移栽效率为240株/min,表明该机构在机械化密植移栽作业中有较高的应用价值。该研究为高密度移栽机植苗机构的研发提供了理论和试验依据,促进了密植型蔬菜钵苗机械化移栽的进程,为密植移栽机的进一步研究提供技术支持和参考。

关键词：密植植苗机构行星轮系运动学分析移栽试验

Design and experimental study of a planetary gearing mechanism based on twice unequal amplitude transmission ratio

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International Journal of Agricultural and Biological Engineering 2022年第1期15卷 155-163页

作者： Jiangang Liu gaohong yu Zhipeng Tong Yao Hua School of Mechanical Engineering&Automation Zhejiang Sci-Tech UniversityHangzhou 310018China College of Mechanical and Electrical Engineering Wuyi UniversityWuyishan 354300FujianChina Zhejiang Province Key Laboratory of Transplanting Equipment and Technology Hangzhou 310018China

To obtain the optimal seedling taking trajectory,this study proposed the adjustment of the total transmission ratio curve by using human-computer interaction.On the basis of this design method,a planetary non-circular gear mechanism was designed that can realize the twice unequal amplitude transmission ratio to meet the seedling harvesting requirements.The cubic non-uniform B-spline curve was used to fit the twice unequal amplitude transmission ratio curve,and the transmission ratio was freely distributed in two levels.The seedling pick-up mechanism was designed by controlling the seedling taking track and the corresponding attitude directly through the local section of the total transmission ratio,and the gear pitch curve was directly controlled by the transmission ratio.The kinematics model of the seedling pick-up mechanism was also established.Furthermore,the influence of the total transmission ratio on the seedling picking track,the ratio of the wave crest to the amplitude,and the mechanism parameters were discussed.A human-computer interactive optimization software was developed using Matlab,and a set of optimal parameters for the seedling pick-up mechanism was obtained to meet the transplanting requirements.By using the Adams software,the virtual prototype simulation of the seedling pick-up mechanism was completed,and the idle experiment for the track and attitude of the prototype was conducted through high-speed camera technology.The theoretical,simulated,and experimental trajectories were consistent with each other.Results revealed that the success rate of the seedling picking exceeded 90%when the rotation speeds were 40 r/min,50 r/min,and 60 r/min,and the qualified rate of the matrix decreased with the increase in rotating speed.Moreover,the number of damaged plants increased with the increase in rotating speed.The experimental results showed that the seedling pick-up mechanism designed using the proposed method demonstrated a good effect and met the required seedling picking performance.

关键词： seedling pick-up mechanism second unequal amplitude planetary gear train seedling picking experiment

Lightweight detection method for lotus seedpod in natural environment

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International Journal of Agricultural and Biological Engineering 2023年第6期16卷 197-206,F0004页

作者： Tao Tang Xu Wang Zenghong Ma Weiwei Hong gaohong yu Bingliang Ye Faculty of Mechanical Engineering Zhejiang Sci-Tech UniversityHangzhou 310018China Key Laboratory of Transplanting Equipment and Technology of Zhejiang Province Hangzhou 310018China Special Equipment Institute Hangzhou Vocational&Technical CollegeHangzhou 310018China

In order to solve the problems of the current target detection algorithms,such as poor discrimination of occluded targets,multiple parameters,complex networks,large amounts of computation,and not conducive to the deployment of mobile terminals,a lightweight lotus seedpod detection method based on YOLOv5s model was proposed in this study.First,the dataset was augmented by using a combination of offline and online augmentation,which improved the adaptability and robustness of the model in complex environments.Then,a lightweight Ghost convolution module was introduced to replace the original convolution,and a lightweight bidirectional feature pyramid network was designed,which could enhance the feature extraction and fusion capability of the network and reduce the amount of calculation and model size;On this basis,the combination of WIoU loss function and Mish activation function was adopted to improve the accuracy of feature extraction.Finally,the knowledge distillation training strategy was used to ensure the proposed lightweight model has the learning ability of a complex network model,improving the recall and precision of model detection.The results of the ablation study show that the proposed method effectively improves the detection performance of the YOLOv5s model for lotus seedpods.The mean average precision of the improved model was 89.7%,compared with the original YOLOv5s model increased by 2.8%,and the parameters and FLOPs were reduced by 2.36M and 7.3G,respectively.Compared with other detection algorithm models,the proposed algorithm model has the advantages of less computation,smaller model size,and higher detection precision.Therefore,the proposed improved optimization method based on the YOLOv5s model can effectively detect lotus seedpods,which provides theoretical research and technical support for intelligent picking of lotus seedpods in the actual operating environment.

关键词： lotus seedpod detection deep Learning data augmentation lightweight knowledge distillation natural environment

Kinematic synthesis and simulation of a vegetable pot seedling transplanting mechanism with four exact task poses

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International Journal of Agricultural and Biological Engineering 2023年第2期16卷 85-95页

作者： Liang Sun Haocong Xu yuzhu Zhou Jiahao Shen gaohong yu Huafeng Hu yuejun Miao Faculty of Mechanical Engineering&Automation Zhejiang Sci-Tech UniversityHangzhou 310018China Zhejiang Province Key Laboratory of Transplanting Equipment and Technology Hangzhou 310018China Hunan Xiangyuan Jinsui Intelligent Equipment Co. LtdLoudi 417700HunanChina Hangzhou Anjie Brake Co. LtdHangzhou 310018China

To obtain a picking and planting integrated transplanting mechanism(PITM)with ideal trajectory shape,reasonable operating attitude,and compact structure for vegetable pot seedling transplanting,a symmetrical structural PITM composed of two planetary carriers and driven by a cam-noncircular gear combination mechanism was proposed in this paper.In accordance with the requirements of transplanting agronomy,the shape of the motion trajectory and the attitude of the end tip of the clamping claw at several specific positions(the starting and end points of picking seedling,the starting point of pushing seedling,and a special point on the return segment)were planned.To make the clamping claws of PITM pass through a set of prescribed positions,the mechanism was simplified to an open-chain 3R mechanism.An accurate four-position-based method for solving the open-chain mechanism model was adopted to obtain the curves of its fixed hinge point(central point)and dynamic hinge point(circle point).The ratio of adjacent bars’lengths was analyzed to determine the feasible interval of the central and circle point curves and the reasonable link length.A desired closed transplanting trajectory that goes through the given points and the corresponding transmission ratio model of the open-chain mechanism was established.After the transmission ratio of each stage of gear and cam pairs was calculated and distributed,the prototype of PITM was designed and manufactured.Lastly,the effectiveness and feasibility of the design were verified through a preliminary experiment of the prototype.

关键词： kinematic synthesis transmission ratio non-circular gear planetary carrier

Properties and Applications of the Eccentric-gear Drive

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Chinese Journal of Mechanical Engineering 2011年第2期24卷 323-331页

作者： ZHAO yun SUN Liang yu gaohong College of Mechanical Engineering and Automation Zhejiang Sci-Tech UniversiO Hangzhou 310018 China

The eccentric-gear can be used for variable speed transmission.But,due to the vibrations caused by variation of backlash in working process,the eccentric-gear is seldom applied in engineering project.There is just a little study about the eccentric-gear.And it is necessary to take a further research on eccentric-gear transmission for the applications in the transplanting mechanism of high-speed rice transplanter.The key of this paper is to extend understanding of three following characteristics of this drive：（1） The rotation-center-distance and the geometrical-center-distance of the two meshing eccentric gears are respectively the hypotenuse and the straight edge of a right triangle in a cycle.（2） The geometrical center line of two meshing gears divides the linking-line of the two rotational centers equally.（3） When two times the eccentricity of gear,the rotation-center-distance and the geometrical-center-distance form a right triangle,the optimal value of rotation-center-distance can be determined.In addition,the kinematic analysis,such as the relationship between contact point and midpoint of the linking-line of two gears＇ rotational centers,transmission ratio between the driving-gear and the driven-gear,contact angle and coordinate of contact point are be made,further the formula for calculation of contact force,flow chart for writing optimization program and curve for analysis of data are also be developed.The relationship between the rotation-center-distance and the geometrical-center-distance,which is determined by three characteristics mentioned above, is a key for the rational design and application of eccentric-gear transmission.Particularly,the presented right triangle property of eccentric gear drive is an important reference for effective analysis of dynamic characteristic of eccentric-gear mechanism and its reliable design.

关键词： eccentric gear transmission property variable speed transmission kinematic and dynamic analysis