Study On The Dynamic Simulation Of Morphological Structure Model Concerned On Overground Part Of Rape

The research of virtual crop which concerns on the morphological structure of crop organs,individuals,and groups simulates the changes and growth processes of morphological structure in a three-dimensional space on the computer.An important aspect of the research on virtual crops has focuses on the analysis and extraction of crop morphological characteristics.At present,the common rape morphological model simulation mostly show interest on the aerial part and root system of rape.This paper mainly analyzed and extracted morphological characteristics of rape based on three-dimensional laser scanning technology,aimed at providing new methods on the management of rape cultivation,the control of plant type and genetic breeding.In this paper,two models were used to obtain rape growth parameters based on three-dimensional laser scanning data.The three-dimensional reconstruction model of rape was adopted to extract the leaf area and the model based on middle leaf vein and leaf curve was employed to extract the length and angle of leaf,in order to realize the goal of non-destructive measurement and monitoring of growth processes.This paper mainly carried out research on virtual rape in the following three aspects:(1)Three-dimensional reconstruction of rape blades.The following steps were used to perform three-dimensional reconstruction of rape leaves: rape point cloud denoising,point cloud simplification,and three-dimensional shape reconstruction.Firstly,the spatial topological relationship between point cloud data of rape was established by the KD tree,and the K-nearest neighbor algorithm and manual assisted de-noising measure were used to eliminate the noise of point cloud data.Secondly,two simplification algorithms separately based on the uniform distribution of point space distance and the leaf curvature were proposed to simplify the blade point cloud data.It could apparently improve the operating efficiency on computer.And the curvature-based point cloud simplification algorithm preserved the detail features of rape plants to the utmost,especially on the veins of the leaves.(2)Curve fitting of rape leaves.In this paper,four kinds of equations were used to fit the midrib of rape: the general quadratic equation,the general cubic equation,Fourier function and sine cluster functions.Through the verification and comparison of the testing parameters,the determination coefficients of model fitting were all up to 0.9700,and LTS-HD could be controlled within 2.0mm.It proved that the fitting results are satisfactory and the fitting goodness of this model is acceptable.Based on the fitting function,the length of rape leaf was calculated by the formula of arc length.Through the statistical test on the simulated results and measured values of the rape leaf,the four functions obtained good fitting effects on the leaf length,which was not significantly different from the measured value.The correlation coefficients were all higher than 0.9.The simulation effect on the leaf length of rapes was acceptable,and the fitting effect of the sine cluster functions proved to be best.It provided a better method for precision measurement of rape.(3)Based on the rape three-dimensional model and leaf curve model,the rape growth parameters of leaf area,leaf length and leaf inclination angle were extracted.Based on the analysis and comparison of rape physiological parameters in different periods,the non-destructive measurement of rape plant was accomplished.The experimental results proved the feasibility of the two models for extracting morphological parameters.