Design of Vegetable Pot Seedling Pick-up Mechanism with Planetary Gear Train

Abstract It has been challenging to design seedling pick-up mechanism based on given key points and trajectories, because it involves dimensional synthesis and rod length optimization. In this paper, the dimensional synthesis of seedling pick-up mechanism with planetary gear train was studied based on the data of given key points and the trajectory of the endpoint of seedling pick-up mechanism. Given the positions and orientations requirements of the five key points, the study first conducted a dimensional synthesis of the linkage size and center of rotation. The next steps were to select a reasonable solution and optimize the data values based on the ideal seedling trajectory. The link motion was driven by the planetary gear train of the two-stage gear. Four pitch curves of noncircular gears were obtained by calculating and distributing the transmission ratio according to the data. For the pitch curve with two convex points, the tooth profile design method of incomplete noncircular gear was applied. The seedling pick-up mechanism was tested by a virtual prototype and a physical prototype designed with the obtained parameter values. The results were consistent with the theoretical design requirements, confirming that the mechanism meets the expected requirements for picking seedlings up. This paper presents a new design method of vegetable pot seedling pick-up mechanism for an automatic vegetable transplanter.

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Novel approach for planetary gear train dimensional synthesis through kinematic mapping

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406219832912 ◽

2019 ◽

Vol 234 (1) ◽

pp. 273-288 ◽

Cited By ~ 1

Author(s):

Liang Sun ◽

Zhenfei Wang ◽

Chuanyu Wu ◽

Guofeng Zhang

Keyword(s):

Angular Displacement ◽

Planetary Gear ◽

Gear Ratio ◽

Gear Train ◽

Transmission Ratio ◽

Dimensional Synthesis ◽

Open Chain ◽

Planetary Gear Train ◽

Kinematic Mapping ◽

Noncircular Gears

The synthesis of a kinematic trajectory traversed by an output link (planet gear) and posture of a planetary gear train with noncircular gears can be divided into two phases: dimensional synthesis of the open-chain 2R mechanism (planetary carrier) and optimization of the transmission ratio of noncircular gear pairs. According to kinematic mapping theory, more than one closed coupler trajectory can be obtained by five preset poses. Simultaneous consideration of the trajectory shape, posture, and gear ratio is difficult during planetary gear train synthesis. This work therefore proposes a new method for the synthesis of planetary gear train in which different path segments in different trajectories are selected and a group of same-type 2R mechanisms is employed to pass through them in order to rebuild a new, closed trajectory. Subsequently, the transmission ratio of noncircular gear pairs can be determined using the relative angular displacement of the 2R mechanism. To improve the roundness of the pitch curves of noncircular gears, two optimization steps are implemented using a genetic algorithm without alternating the data points of the requisite open trajectories. For example, a mechanism for rice pot seedling transplanting is obtained by using the method.

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A novel planar motion generation method based on the synthesis of planetary gear train with noncircular gears

Journal of Mechanical Science and Technology ◽

10.1007/s12206-019-0933-6 ◽

2019 ◽

Vol 33 (10) ◽

pp. 4939-4949 ◽

Cited By ~ 1

Author(s):

Jun Ye ◽

Xiong Zhao ◽

Ying Wang ◽

XinCheng Sun ◽

JianNeng Chen ◽

...

Keyword(s):

Planetary Gear ◽

Gear Train ◽

Planar Motion ◽

Motion Generation ◽

Planetary Gear Train ◽

Noncircular Gears

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Geometric design and kinematics analysis of coplanar double internal meshing non-circular planetary gear train

Advances in Mechanical Engineering ◽

10.1177/1687814018818910 ◽

2018 ◽

Vol 10 (12) ◽

pp. 168781401881891 ◽

Cited By ~ 1

Author(s):

Chao Lin ◽

Xiguang Xia ◽

Peilu Li

Keyword(s):

Design Method ◽

Planetary Gear ◽

Gear Train ◽

Prototype Model ◽

Kinematics Analysis ◽

Planetary Gear Train ◽

Kinematics Simulation ◽

Adams Software ◽

New Type ◽

Internal Meshing

A new type of non-circular planetary gear train is proposed, in which the planetary gear is internally meshed with the sun gear and the ring gear at the same time. The structural form and transmission principle are analyzed, and the design method of non-circular gear pitch curves and related parameters of the gear train are discussed. The input–output relationship under various working conditions of the gear train is deduced. The precise tooth profile of the non-circular gears is obtained by the Boolean operation of MATLAB, then the virtual prototype model of the planetary gear train is established, and the kinematics simulation is carried out in the ADAMS software. The simulation results verify the correctness of the transmission principle and the theoretical analysis of the motion law.

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Research on design method of non-circular planetary gear train transplanting mechanism based on precise poses and trajectory optimization

Advances in Mechanical Engineering ◽

10.1177/1687814018814368 ◽

2018 ◽

Vol 10 (12) ◽

pp. 168781401881436

Author(s):

Xiong Zhao ◽

Mengyan Chu ◽

Xingxiao Ma ◽

Li Dai ◽

Bingliang Ye ◽

...

Keyword(s):

Trajectory Optimization ◽

Design Method ◽

Planetary Gear ◽

Trajectory Control ◽

Gear Train ◽

Control Points ◽

Transmission Performance ◽

Planetary Gear Train ◽

Precise Position ◽

Solution Domain

Among all kinds of transplanting mechanisms which are the important parts of transplanters, the planetary gear train transplanting mechanism is widely used for its excellent transmission performance, but it is difficult to design the gear pitch curves and structural parameters according to the trajectory and pose requirements of transplanting. The current design method of the non-circular planetary gear train transplanting mechanism cannot ensure the precise position and posture in the crucial points of transplanting trajectory, nor take both the anticipated trajectory and the smoothness of the gear pitch curves into account, it will only get one solution which is available for mechanism design. In order to solve those problems, the non-circular planetary gear train transplanting mechanism is analyzed as a combination of the bar-group and gear train system. According to the transplanting requirements, three points with precise position and posture which called pose points in the trajectory are given to obtain the solution domain of the parameters of bar-group, and then trajectory shape control points are inlet to design the desired shape of the transplanting trajectory and obtain the transmission ratio curve which can be used to get the gear pitch curve. The most suitable parameters of bar-group in solution domain are selected based on the smoothness of the gear pitch curves. This article establishes three-dimensional model of the mechanism and utilizes the ADAMS to carry out a motion simulation; all simulation results are consistent with theoretical design results, which confirm that the design method based on prescribed pose points and trajectory control points is adequate for the transplanting mechanism. With the proposed method, the selectivity of the mechanism’s parameters solution is increased, and transmission performance benefits from the integrated design of trajectory control and the smoothness of the pitch curves.

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ON THE NEW MECHANICAL PRESS WITH A PLANETARY GEAR TRAIN

Transactions of the Canadian Society for Mechanical Engineering ◽

10.1139/tcsme-2016-0004 ◽

2016 ◽

Vol 40 (1) ◽

pp. 45-58 ◽

Cited By ~ 1

Author(s):

Ren-Chung Soong

Keyword(s):

Dynamic Performance ◽

Planetary Gear ◽

Cost Effective ◽

Gear Train ◽

Dimensional Synthesis ◽

Linkage Mechanism ◽

Planetary Gear Train ◽

The Press ◽

Mechanical Press ◽

Crank Mechanism

A new 1-DOF mechanical press with a geared eight-bar linkage mechanism is presented. The proposed press can generate the required kinematic and dynamic performance for drawing, stamping, deep drawing, and precision cutting processes by simply adjusting the offset of the ram. The press consists of an elementary planetary gear train with a pair of planet gears, a slider-crank mechanism, and a slider-crank mechanism with a variable-length crank. The configuration and a solid model are described, and a kinematic analysis, dynamic analysis, and optimized dimensional synthesis of the press are discussed. Examples are provided to verify the feasibility and effectiveness of the design methodology. The proposed press could lead to more flexible and cost-effective applications.

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Analysis and Design of a Spatial Planetary Noncircular Gear Train for Rice Seedling Transplanting Based on Three Given Positions

Transactions of the ASABE ◽

10.13031/trans.13498 ◽

2020 ◽

Vol 63 (1) ◽

pp. 165-176

Author(s):

Liang Sun ◽

Yuzhu Zhou ◽

Hengmin Huang ◽

Chuanyu Wu ◽

Guofeng Zhang

Keyword(s):

Lateral Displacement ◽

Kinematic Model ◽

Planetary Gear ◽

Gear Train ◽

Transmission Ratio ◽

List Type ◽

Gear Pair ◽

Planetary Gear Train ◽

Analysis And Design ◽

Noncircular Gears

HighlightsA method for solving a spatial transplanting mechanism with noncircular gears is proposed.A new mechanism for transplanting rice pot seedlings is proposed.A trajectory with a small lateral displacement at the preparation phase is obtained.The working performance is validated by simulations and field tests.Abstract. This study proposes a method of solving the parameters of a spatial planetary gear train with noncircular gears to meet the requirements of wide-narrow row pot seedling transplanting (WPST). First, the planetary gear train was simplified to a spatial open-chain 2R mechanism (planetary carrier). A kinematic model of the 2R mechanism was derived from the three given homogeneous matrices describing the spatial position and attitude information of grasping, extracting, and planting seedlings. Second, the length of each link, attitude of each rotation axis, and relative initial angles were calculated. The model for solving the transmission ratio was deduced. A spatial planetary gear train configuration with a single planet carrier and two-stage driving was derived, in which the middle axis could be determined by combining the selected configuration, represented trajectory, and transmission ratio of each gear pair. Finally, a planetary gear train combining a noncircular gear pair and a helical gear pair was used in the WPST mechanism design. Simulations and tests conducted on a prototype confirmed the correctness of the theoretical model and the practicality of the design. Keywords: Noncircular gear, Planetary gear train, Spatial trajectory, Transmission ratio, Transplanting mechanism.

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Dynamic Characteristics of Double Helical Planetary Gear Train With Tooth Friction

Volume 10: ASME 2015 Power Transmission and Gearing Conference; 23rd Reliability, Stress Analysis, and Failure Prevention Conference ◽

10.1115/detc2015-48022 ◽

2015 ◽

Cited By ~ 1

Author(s):

Fengxia Lu ◽

Rupeng Zhu ◽

Haofei Wang ◽

Heyun Bao ◽

Miaomiao Li

Keyword(s):

Degrees Of Freedom ◽

Sliding Friction ◽

Planetary Gear ◽

Gear Train ◽

Variable Step Size ◽

Step Size ◽

Planetary Gear Train ◽

Gear Mesh ◽

Meshing Stiffness ◽

Nonlinear Dynamics Model

A new nonlinear dynamics model of the double helical planetary gear train with 44 degrees of freedom is developed, and the coupling effects of the sliding friction, time-varying meshing stiffness, gear backlashes, axial stagger as well as gear mesh errors, are taken into consideration. The solution of the differential governing equation of motion is solved by variable step-size Runge-Kutta numerical integration method. The influence of tooth friction on the periodic vibration and nonlinear vibration are investigated. The results show that tooth friction makes the system motion become stable by the effects of the periodic attractor under the specific meshing frequency and leads to the frequency delay for the bifurcation behavior and jump phenomenon in the system.

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