Development and Testing of a Cam Disc Comb-Type Picking Machine for Chrysanthemum (Dendranthema morifolium Ramat. Tzvelev)

2021 ◽  
Vol 64 (6) ◽  
pp. 1967-1976
Author(s):  
Rongyan Wang ◽  
Zhian Zheng ◽  
Lei Gao ◽  
Andi Chen ◽  
Shanyu Wang ◽  
...  
Keyword(s):  
Rotational Speed ◽  
Power Transmission ◽  
Three Dimensional ◽  
Field Tests ◽  
Physical Parameters ◽  
List Type ◽  
Three Dimensional Model ◽  
Structure And Motion ◽  
Breakage Rate ◽  
Drop Rate

HighlightsA practical cam disc comb-type chrysanthemum picking machine was developed.A three-dimensional model of the picking machine was designed in SolidWorks.The working principle and motion trajectory of the picking comb teeth were analyzed.The best working parameters of the picking machine were obtained with field tests.Abstract. Aiming at the problems of labor, picking efficiency, and mechanization, a small practical cam disc comb-type chrysanthemum picking machine was designed. The picking machine, mainly composed of a wheeled frame, power transmission system, cam disc, picking comb, and cleaning comb sleeve, uses the pulling force of comb teeth to pick chrysanthemum flowers. The comb teeth rotate on a central shaft, and their swing angle is determined by a groove on the cam disc. One rotation of the comb teeth completes the process of picking, lifting, and unloading. In this study, the parameters of the cam profile were designed using an analytical method. To ensure reliability of the components, the trajectory of the comb teeth and their structure and motion parameters were analyzed, and the conditions for picking chrysanthemums were determined. The physical parameters of chrysanthemum plants were measured, and a prototype picking machine was built. Field tests were conducted using the comb rotational speed, comb teeth spacing, and comb working depth as the test factors and the picking rate, impurity rate, breakage rate, and drop rate as the evaluation indexes. The effects of each factor and the interaction of any two factors on the picking effectiveness were obtained. The test results suggested that the most effective harvesting was achieved when the comb rotational speed was 40 rpm, the comb teeth spacing was 8 mm, and the comb working depth was 200 mm. With these parameters, the picking rate was 93.28%, the breakage rate was 1.21%, the impurity rate was 8.38%, and the drop rate was 6.61%. The prototype machine achieved good picking effectiveness, and this study provides a technical foundation for the realization of mechanized chrysanthemum harvesting. Keywords: Cam, Chrysanthemum, Comb teeth, Motion track, Picking machine.

scholarly journals Numerical study of dispersion and hydrodynamic connectivity of near-surface waters in Lake Huron

2012 ◽  
Vol 47 (3-4) ◽  
pp. 238-251 ◽  
Author(s):  
Jun Zhao ◽  
Yerubandi R. Rao ◽  
Jinyu Sheng
Keyword(s):  
Surface Waters ◽  
Numerical Study ◽  
Three Dimensional ◽  
Coastal Region ◽  
Lake Huron ◽  
Physical Parameters ◽  
Three Dimensional Model ◽  
Near Surface ◽  
Georgian Bay ◽  
Main Lake

A nested-grid hydrodynamic modeling system is used to examine the circulation and dispersion in Lake Huron and adjacent areas with specific attention to physical parameters pertinent to the estimation of hydrodynamic connectivity of near-surface waters. The nested system is forced by monthly mean surface heat flux and 12-hourly wind stress computed from wind speeds extracted from the National Centers for Environmental Prediction of the National Center for Atmospheric Research (NCEP/NCAR) 40-year reanalysis data. The three-dimensional model currents are used to calculate the retention and dispersion of conservative, near-surface particles carried by the currents. The near-surface dispersion is relatively low in Saginaw Bay, eastern Georgian Bay and the eastern North Channel; and relatively high over the western part of the main lake and the coastal region of south Lake Huron. The hydrodynamic connectivity in the surface water and connectivity matrices are calculated from particle movements carried passively by model currents superposed by a random walk process. The model results demonstrate that the hydrodynamic connectivity in the North Channel and Georgian Bay (ranging from 0.9 to 2.2%) is much weaker than those in the main lake (5.3 to 21.9%).

scholarly journals Light curve variation caused by accretion column switching stellar hemispheres

2019 ◽  
Author(s):  
Miljenko Čemeljić ◽  
Michał Siwak
Keyword(s):  
Light Curve ◽  
Hot Spots ◽  
Rotation Axis ◽  
Three Dimensional ◽  
Column Switching ◽  
Stellar Surface ◽  
Physical Parameters ◽  
Stellar Rotation ◽  
Three Dimensional Model ◽  
Ring Section

Abstract We investigate switching of the accretion column between the stellar hemispheres in the magnetosphere of a star with the dipole magnetic field aligned with the stellar rotation axis. We show that such switching can produce “hiccups” in the observed lightcurves. The intensity of emitted radiation from the stellar surface as seen by distant observers is computed from our two dimensional axisymmetric viscous and resistive magnetohydrodynamic numerical simulations. This result is used to construct a three-dimensional model of a star with the ring-shaped hot spots from the accretion columns at the stellar surface. We compute the intensity from such hot spots. To obtain a non-axisymmetric model with arc-shaped hot spots, we remove a ring section in the azimuthal direction from the hot-spots and compute the intensity of the radiated emission. Such models can be used to relate physical parameters in the simulations to the observations. We show an example with the intensity computed from our model compared to observational light curve.

Kinematics Analysis and Trajectory Planning of Segmentation Robot for Chilled Sheep Carcass

2021 ◽  
Vol 37 (6) ◽  
pp. 1147-1154
Author(s):  
Xiulan Bao ◽  
Leng Junsong ◽  
Jincheng Mao
Keyword(s):  
Trajectory Planning ◽  
Automatic Segmentation ◽  
Three Dimensional ◽  
Animal Husbandry ◽  
List Type ◽  
Three Dimensional Model ◽  
Robot System ◽  
Contour Segmentation ◽  
Before And After ◽  
Cutting Path

HighlightsAn automatic sheep segmentation robot system was developed to realize the automatic segmentation of chilled sheep carcass and improve the segmentation efficiency.The mechanical properties of mutton and lamb ribs were analyzed.The motion model of robot was established and the cutting path of sheep carcass was designed.Accurate segmentation of sheep carcass was realized.Abstract. With the quick development of animal husbandry, it is imperative to switch from extensive management to intensive operation. To improve the automation and quality of mutton segmentation, an automatic sheep segmentation robot system was developed in this article, which realizes the automatic segmentation of chilled sheep carcass and improves the segmentation efficiency of chilled sheep carcass. According to the technological requirements of sheep carcass segmentation, the cutting procedure of slaughtering chilled fresh sheep carcass was designed and the three-dimensional model of chilled fresh sheep carcass was established in reverse. A chilled fresh sheep carcass clamp was designed based on the characteristics of the profiling structure. Then the mechanical characteristics of chilled fresh mutton and sheep ribs were analyzed. Specifically, considering that the carcass of chilled fresh sheep is a viscous body, the shear test of chilled fresh mutton tissue was carried out. Thus, the kinematics model of segmentation robot was established. The workspace of the slaughtering robot was analyzed. Furthermore, the dynamic model of a slaughtering robot was established. The cutting track of the segmentation robot was designed and the sheep carcass cutting experiment was completed on the segmentation robot system. The mass of sheep carcass before and after cutting were 15.3 and 14.9 kg, respectively. The loss rate during cutting was 2.61%, which indicates the incision was smooth and the sheep carcass segmentation was accurate. The effectiveness of the sheep carcass segmentation robot was proved by experimental results. Keywords: Cutting force, Reverse modeling, Sheep contour, Segmentation robot, Trajectory planning.

Rigid–flexible coupling dynamics with contact estimator for robot/PTL system

2020 ◽  
Vol 234 (4) ◽  
pp. 635-649
Author(s):  
Xiaoliang Zheng ◽  
Gongping Wu ◽  
Wei Jiang ◽  
Fei Fan ◽  
Jiale Zhu
Keyword(s):  
Power Transmission ◽  
Screw Theory ◽  
Three Dimensional ◽  
Nonlinear Dynamic Analysis ◽  
Rigid Bodies ◽  
Operating Conditions ◽  
Three Dimensional Model ◽  
Flexible Coupling ◽  
Coupling Approach ◽  
Coupling Dynamics

In order to enhance sampling efficiency and security when robot maintains power transmission line (PTL), this article develops a new approach for the rigid-flexible coupling dynamics of robot/PTL system, which decouples the large system into two small systems and solves them separately by estimating the contact force. The robot is modelled as a system of rigid bodies by screw theory, while the PTL system is modelled using absolute node coordinate formulation (ANCF). The integration of screw theory, ANCF and contact estimator trained by artificial neural network has not been accomplished before in the literature. The main contribution of this paper is to achieve this integration with the goal of developing a new and general approach for the nonlinear dynamic analysis of the interaction of the rigid maintenance robot with flexible PTL cable. A simplified two-dimensional example is used to compute the effect of the robot/PTL interaction under different operating conditions to have an understanding of the coupling approach between the two systems. A more detailed three-dimensional model was developed, and the results obtained validate the utility and effectiveness of our approach.

Buckling Analysis of Large-Scale Transmission Tower Structure

2014 ◽  
Vol 494-495 ◽  
pp. 1678-1681
Author(s):  
Xiang Zan Xie ◽  
Rui Jun Zhang
Keyword(s):  
Transmission Lines ◽  
Large Scale ◽  
Power Transmission ◽  
Flexible Structures ◽  
Three Dimensional ◽  
Transmission Tower ◽  
Three Dimensional Model ◽  
Buckling Mode ◽  
Large Power ◽  
Tower Structure

The high-voltage transmission tower transmission lines is a major component and typically a high steel tower, is a tall, flexible structures. In this paper, the finite element method to establish a large-scale three-dimensional model of the transmission tower space, computational analysis of the transmission tower structure first six buckling modes and critical load, examined the order buckling mode characteristics. Research on the structural stability of large power transmission tower design has some theoretical significance and application value.

Dynamics Simulation of Large Tower Structure Lifting Process Based on CABLE Modeling

2014 ◽  
Vol 533 ◽  
pp. 145-153
Author(s):  
Hong Zhi Zhang ◽  
Xuan Yu Sheng
Keyword(s):  
Steel Wire ◽  
Three Dimensional ◽  
Wire Rope ◽  
Dynamics Simulation ◽  
Physical Parameters ◽  
Dimensional Model ◽  
Analysis Model ◽  
Three Dimensional Model ◽  
Tower Structure ◽  
Eccentric Structure

In this paper, three-dimensional model of the flexible steel wire rope was established by using CABLE software in CATIA software. After defining the physical parameters of the steel wire rope, the dynamics analysis model of wire rope was established in motion workbench. Further fully model was assembled and simulated including cranes, tower, ground in motion workbench. Finally, we obtained hoisting structure of the trajectory curve, dynamic response, eccentric structure, flipping, etc., as well as interference with the surrounding objects.

scholarly journals Experimental and Theoretical Investigation on Nonlinear Behavior of Cable-Stayed Bridges

2009 ◽  
Author(s):  
Guilhem Michon ◽  
Alain Berlioz ◽  
Claude-Henri Lamarque
Keyword(s):  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Nonlinear Behavior ◽  
Physical Parameters ◽  
Three Dimensional Model ◽  
Analytical Treatment ◽  
Secondary Resonances ◽  
Inclined Cable ◽  
Continuation Technique ◽  
Cable Stayed Bridges

This paper deals with experimental study and with understanding via a finite number of degrees of freedom model of the vibrations of an inclined cable linked to a continuous beam. This is a simplified version of deck and cable of a bridge. External excitation is exerted on the beam. The cable attached to the end of the beam is submitted to a vertical sinusoidal solicitation due to the response of the finite stiffness beam. The excitation of the cable though it is more complex looks similar to the excitation used in previous works. A guided device located at the end of the beam ensures the excitation with a variation of the horizontal component of the cable tension that introduces a new parametric excitation. Analysis of preliminary experimental results for main and secondary resonances permits us to consider simple modeling with one degree of freedom systems obtained by projection of the continuous three-dimensional model of the cable on adapted Irvine mode. Analytical treatment of these models involving data from the experimental devices shows a correct qualitative agreement between preliminary experiments and theoretical. Continuation technique are used to highlight the influence of physical parameters.

Three-Dimensional Simulation of the Influences of Operational Parameters on Stability of Formation-Cement Sheath-Casing Combination

2020 ◽  
Vol 980 ◽  
pp. 525-546
Author(s):  
Yong Wen Yuan ◽  
Yan Jun Cheng ◽  
Jin Xin Zhu ◽  
Liu Yi Li
Keyword(s):  
Cross Section ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Physical Parameters ◽  
Dimensional Model ◽  
Operational Parameters ◽  
Three Dimensional Model ◽  
Cement Sheath ◽  
The Stability ◽  
Casing Pressure

At present, most of the studies of the stability of the formation-cement sheath-casing combination have been mainly based on the plane, and the three-dimensional model established is only one example. There is no systematic study of the influence of physical parameters and process parameters on the stability of the combined body under the three-dimensional model and the action of triaxial crustal stress. Through the establishment of three-dimensional formation-cement sheath-casing linear elastic combination model, we can study the influence of operational parameters (cement sheath pressure, casing cross section pressure, inner casing pressure, ellipticity of borehole, centrality of casing, thickness of cement sheath) by the two interfaces’ Von Mises stress and the total displacement of the combination body. It is pointed out that the pressure of cement sheath, and casing cross section pressure have no effect on the stability of formation, cement sheath and casing; The higher the ellipticity of the borehole, the eccentricity of the casing (position 1, 2) and the thickness of the cement sheath, the higher the stability of the second interface of the cementing; The higher the inner casing pressure and the eccentricity of the casing(position 3), the lower the stability of the second interface of the cementing; The higher the eccentricity of the casing (position 2,3) and the thickness of the cement sheath, the higher the stability of the first interface of the cementing; The higher the inner casing pressure, the eccentricity of the casing (position 1) and the ellipticity of the borehole, the lower the stability of the first interface of the cementing; The higher the eccentricity of the casing (position 2,3) and thickness of the cement sheath, the higher the stability of the casing; The higher the inner casing pressure, the ellipticity of the borehole and the eccentricity of the casing(position 1), the lower the stability of the casing. Through this study, according to the formation stress, the formation physical parameters (elastic modulus, Poisson's ratio, density), optimize the operational parameters, ensure the long-term integrity of the combination.

scholarly journals Research on Mechanical Properties of High-Pressure Anhydrite Based on First Principles

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 240
Author(s):  
Xianren Zeng ◽  
Shihui You ◽  
Linmei Li ◽  
Zhangli Lai ◽  
Guangyan Hu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Bulk Modulus ◽  
Young’S Modulus ◽  
First Principles ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Three Dimensional ◽  
Poisson's Ratio ◽  
Physical Parameters ◽  
Three Dimensional Model

This article focuses on the elucidation of a three-dimensional model of the structure of anhydrite crystal (CaSO4). The structure parameters of anhydrite crystal were obtained by means of first principles after structure optimization at 0~120 MPa. In comparison with previous experimental and theoretical calculation values, the results we obtained are strikingly similar to the previous data. The elastic constants and physical parameters of anhydrite crystal were also studied by the first-principles method. Based on this, we further studied the Young’s modulus and Poisson’s ratio of anhydrite crystal, the anisotropy factor, the speed of sound, the minimum thermal conductivity and the hardness of the material. It was shown that the bulk modulus and Poisson’s ratio of anhydrite crystal rose slowly with increasing pressure. The anisotropy characteristics of the Young’s modulus and shear modulus of anhydrite crystal were consistent under various pressure levels, while the difference in the anisotropy characteristics of the bulk modulus appeared. The acoustic velocities of anhydrite crystal tended to be stable with increasing pressure. The minimum thermal conductivity remained relatively unchanged with increasing pressure. However, the material hardness declined gradually with increasing pressure.

A Test of the Simulation of Tropical Convective Cloudiness by a Cloud-Resolving Model

2009 ◽  
Vol 22 (11) ◽  
pp. 2834-2849 ◽  
Author(s):  
Mario A. Lopez ◽  
Dennis L. Hartmann ◽  
Peter N. Blossey ◽  
Robert Wood ◽  
Christopher S. Bretherton ◽  
...  
Keyword(s):  
Rain Rate ◽  
Strong Dependence ◽  
Three Dimensional ◽  
Longwave Radiation ◽  
Physical Parameters ◽  
Model Parameters ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Cloud Resolving Model ◽  
Upper Level

Abstract A methodology is described for testing the simulation of tropical convective clouds by models through comparison with observations of clouds and precipitation from earth-orbiting satellites. Clouds are divided into categories that represent convective cores: moderately thick anvil clouds and thin high clouds. Fractional abundances of these clouds are computed as a function of rain rate. A three-dimensional model is forced with steady forcing characteristics of tropical Pacific convective regions, and the model clouds are compared with satellite observations for the same regions. The model produces a good simulation of the relationship between the precipitation rate and optically thick cold clouds that represent convective cores. The observations show large abundances of anvil cloud with a strong dependence on rain rate, but the model produces too little anvil cloud by a factor of about 4 and with a very weak dependence on the rain rate. The observations also show probability density functions for outgoing longwave radiation (OLR) and albedo with maxima that correspond to extended upper-level cold clouds, whereas the model does not. The sensitivity of the anvil cloud simulation to model parameters is explored using a two-dimensional model. Both cloud physical parameters and mean wind shear effects are investigated. The simulation of anvil cloud can be improved while maintaining a good simulation of optically thick cloud by adjusting the cloud physics parameters in the model to produce more ice cloud and less liquid water cloud.

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