During the harvesting process of Cerasus humilis, the fruits are susceptible to compression and impacts from the combing teeth, leading to internal damage to the pulp and rupture of the peel. This compromises the quality of the harvested fruits and subsequent processing, resulting in significant economic losses. To investigate the mechanical behavior of Cerasus humilis fruit, this study measured the geometric parameters as well as the mechanical properties (failure load, elastic modulus, compressive strength, and fracture energy) of the peel, pulp, and core in both the axial and radial directions. A geometric model of Cerasus humilis fruit was constructed using three-dimensional reverse engineering technology. The rupture process of the fruit under compressive loading was simulated and analyzed using Abaqus software (Version 2023). The damage mechanisms were investigated, and the accuracy and reliability of the finite element model were validated through compression experiments. The experimental results indicated that the mechanical properties of the peel of Cerasus humilis fruit exhibited no significant differences between the axial and radial directions, allowing it to be regarded as an isotropic material. In contrast, the mechanical properties of the pulp and core showed significant differences in both directions, demonstrating anisotropic characteristics. Additionally, the axial compressive strength of the Cerasus humilis fruit was higher than its radial compressive strength. The simulation results revealed that during axial compression, when the surface stress of the peel reached 0.08 MPa, the fruit completely fractured. The location and morphology of the cracks in the simulation were consistent with those observed in the experimental results. Furthermore, under different compression directions, the force–displacement curves obtained from actual compression tests closely aligned with those from the finite element simulations. The finite element model established in this study effectively simulates and predicts the cracking and internal damage behavior of Cerasus humilis fruit under compressive loads. This research provides a theoretical foundation and technical guidance for reducing mechanical damage during the harvesting process of Cerasus humilis.

In this study,the mechanical properties of three varieties of cerasus humilis at different temperatures were systematically investigated by whole fruit puncture test, exocarp uniaxial tensile test and mesocarp uniaxial compression test.It was found that puncture test could not only reflect the shear mechanics of the exocarp in vivo at the tissue level, but also characterize the resistance level of fruit to puncture damage at the macro level.The environmental temperature had significant negative and positive effects on puncture failure stress and puncture failure deformation of cerasus humilis (p<0.05).The stress and elastic modulus of exocarp tension and mesocarp compression were significantly affected by ambient temperature (p<0.05).This study combined with temperature change to study the mechanical properties of cerasus humilis provides a necessary theoretical basis for the prediction of fruit damage and the development of postharvest treatment equipment.

This paper addresses the problem of the lack of intrinsic and contact parameters when applying the discrete element method to simulate and analyze the key aspects of white kidney bean seed sowing, harvesting and clearing. The experiment took white kidney bean seeds as the research object, measured the intrinsic parameters of white kidney bean seeds by using the universal testing machine, and measured the collision recovery coefficient of 0.445, static friction coefficient of 0.452 and rolling friction coefficient of 0.091 between white kidney bean seeds and Q235 steel plate by physical test and EDEM discrete element simulation parameter calibration. The stacking experiment was carried out by the cylinder lifting method, numerical processing was performed with MATLAB, and the actual stacking angle of white kidney bean seeds was 31.28°. The steepest climbing test was designed with the interspecific contact parameters as factors and the relative error between the actual and simulated stacking angles as indicators. The optimal combination of the interspecific contact parameters of white kidney bean was determined by response surface optimization analysis, and the interspecific collision recovery coefficient of white kidney bean was obtained as 0.39, static friction coefficient was 0.53, rolling friction coefficient was 0.092. Using the optimal parameters for the simulation test, the relative error between the actual stacking angle of white kidney bean seeds and the simulated stacking angle was 1.63%, indicating that the calibrated simulated contact parameters were reliable and could provide reference for the discrete element simulation of white kidney bean seeds.

In this study, a central unloading reel structure was proposed to achieve continuous harvest of Cerasus humilis, and an indoor test bench was constructed to carry out the combing test of branches. The cross-section of the comb was made of an isosceles triangle, and an orthogonal test was carried out with tooth gap, winch rotational velocity and cross-section base angle as test factors, and fruit breakage rate and leakage rate as test indicators. The results show that the tooth gap and winch rotational velocity have a significant influence on the breakage rate, and the tooth gap and section bottom angle have a significant influence on the fruit leakage rate. Considering the comprehensive loss rate, the appropriate deformation of the comb teeth and the manufacturing difficulty, the optimal values of the three test factors are 10 mm, 130 r/min, and 45°, respectively. At the same time, the maximum combing force of a single branch through the comb is 240 N through the pressure sensor of the test bench. The experimental results can be used as the basis for the structural design of continuous harvesting head.

A sunken solar greenhouse is the original type of greenhouse in China, its soil wall thermal storage performance is better and low cost. Higher benefits of stereoscopic planting in sunken solar greenhouses, while repeated use of the substrate can produce pathogens, so high-temperature smothering is used for sterilization in the summer months of June to August. To investigate the mechanism of indoor temperature and humidity variation and fungicidal effect in a sunken solar greenhouse, a single cross-sectional test of temperature and humidity in sunken solar greenhouse during the smothering period was conducted using wireless sensors. The results showed that: The maximum value of indoor temperature at noon was 69.5°C the temperature value of all measurement points was greater than 50°C for 3h, when removing the measurement points at the upper surface of the ground, the relative humidity value of other measurement points was less than 60% for 5h. During the daytime period, when the indoor temperature is greater than 28°C in the interval 7:00-12:00, the initial relative humidity value of each measurement point is located at 70%-85%; when the weighted temperature of each measurement point starts to rise at a rate of 1.1°C/10min, the weighted humidity of each measurement point declining is 1.3%/10min; the determination of the rate of change of indoor temperature and humidity during the daytime and the starting value can provide a basis for indoor plants to take measures to sterilize at high temperature.

The contact parameters between calcium fruit and comb teeth are the key to the virtual picking test. In this paper, the physical test of free-falling impacting plate on the self-built test bench and the centre rotation composite simulation test of rigid body dynamics were carried out. The relationship between the contact parameters and dynamic characteristics was obtained, and the contact model was optimized. The contact stiffness k=0.868, force index e=1.91 and damping C=5.56E-4 were obtained when the height of the free falling body was 500 mm. The model was applied to lower free-fall simulation test, and the obtained results were in good agreement with the physical test results. The contact model can be used in the subsequent picking simulation.

The sunken solar greenhouse is suitable for the development of vertical planting, which results in higher yield. In order to investigate the effect of temperature on photosynthesis of plants, an experimental study was conducted on the temperature and photosynthesis of strawberry plants at different heights in the sunken solar greenhouse. The study showed that when the indoor temperature was higher than 25.5℃, the photosynthesis of plants was inhibited; the transpiration rate decreased by 3.89 and photosynthesis rate decreased by 3.95 when the air temperature increased from 25.5℃ to 33.3℃ and then decreased to 25.4℃ at a height of 1.8m from the indoor floor; there were temperature differences in the vertical direction between the indoor temperatures of the sunken heliostat. The maximum temperatures at 0 m, 0.6 m, 1.0 m, 1.4 m, and 1.8 m height were 20.6°C, 24.1°C, 25.4°C, 25.4°C, 33, and 3°C, respectively, and different temperatures would have different photosynthetic characteristics of plants. This study can provide basic support for greenhouse regulation.

针对机械原理课程采用传统考核形式与新教学模式不匹配,无法充分培养学生工程能力的问题,突出课程性质及学生主体地位,发挥考核方式激励作用.从具体实践出发,在保障学生适应性良好的前提下,考核中引入多项侧重于培养学生工程能力和创新能力的措施.学生对实践项目的关注度、课业成绩及大赛成绩较以往有明显提升,在一定程度上反映此次探索的成效.

The mechanical parameters of Cerasus humilis are the basic data for subsequent studies on fruit deformation, damage, and movement characteristics during harvesting and transportation, but these parameters are rarely reported. Relevant mechanical parameters of whole fruit compression are calculated by comparing physical tests and virtual simulations. The orthogonal rotating combined experimental design was used to arrange the simulation tests, with the elastic modulus (E), yield limit (Ey), and tangent modulus (Et) as the influence factors and compression force as the result. Response surface optimization was employed to find the closest test point to the force–deformation curve of the physical test. The parameters of the pulp test point are as follows: E = 0.923 MPa, Ey = 0.0897 MPa, and Et = 0.478 MPa. Results show that the step on the force–deformation curve was not the beginning of the pulp yield, which was substantially earlier than the strain rate at the simulation step. The region of increased stress in the pulp first appeared at the junction with the core due to stress concentration. Combining virtual and physical tests to solve the mechanical parameters of fruits is more suitable than testing the standard pulp sample.

为确定蚕豆种子离散元模型仿真参数,采用基本球单元组合方法建立蚕豆种子离散元模型.通过物理试验测定蚕豆种子与钢板间接触参数,在EDEM软件中对蚕豆种子离散元仿真参数进行标定,得到蚕豆种子与钢板间碰撞恢复系数为0.46、静摩擦系数为0.437和滚动摩擦系数为0.053.以种间接触参数为因素,以实测堆积角与仿真堆积角相对误差为指标,进行最陡爬坡试验、3因素二次正交旋转组合设计试验,得到蚕豆种间碰撞恢复系数为0.25、静摩擦系数为0.53和滚动摩擦系数为0.083.利用最佳参数组合进行仿真试验,蚕豆种子堆积角实测值与仿真值的相对误差为1.1％.结果表明,标定的仿真接触参数可用于蚕豆种子颗粒的离散元仿真.

In view of the problem of plant entanglement threshing roller in the process of mechanized flax harvesting, a comb-brush air-suction composite flax capsule harvesting test stand was designed based on the harvesting method of harvesting capsules independently and then breaking the capsules to thresh them. The following four parameters were selected as experimental factors: the shape of comb tooth cross-section, the rotational speed of comb roller, the relative speed of machine travel and the air volume of centrifugal fan. The following four indicators were chosen as the experimental indicators: capsule removal rate, capsule breakage rate, capsule collection rate and plant winding rate. A four-factor and three-level orthogonal test was conducted. The results showed that the optimal combination of test factors was as follows: the shape of comb tooth cross-section was rectangular, the rotational speed of the brush roller was 90 rad/min, the speed of machine travel relative to the plant was 80 mm/s and the air volume of centrifugal fan was 6000 m3/h. Under the condition of better experiment parameters combination, the capsule removal rate was 96.45%, capsule shell breaking rate was 98.79%, capsule collection rate was 95.65% and flax plants winding rate was 2.52%. The comb-brush air-suction composite flax capsule harvesting test bench provided the feasibility scheme for the problem of plant winding thresher roller and capsule collection.

针对亚麻(胡麻)机械化收获过程中植株缠绕脱粒滚筒问题和蒴果收集问题,设计了梳刷气吸式亚麻(胡麻)蒴果收获试验台.以梳齿截面形状、梳刷滚筒转速、机具行进相对速度、离心式通风机风量为试验因素,以蒴果收集率、植株缠绕率为试验指标,进行了4因素3水平正交试验.结果表明,在较优试验因素组合的梳齿截面形状为圆形、梳刷滚筒转速44 r/min、机具行进相对速度80 mm/s、离心风机风量6 000 m3/h作业条件下,蒴果收集率为96.67％、植株缠绕率为0.32％,试验台的梳脱、收集、避免植株缠绕等效果较好.梳刷气吸式亚麻(胡麻)蒴果收获试验台提供了解决植株缠绕脱粒滚筒问题和蒴果收集问题的可行性方案.

研究分析成熟期花椒的力学特性,旨在为花椒机械采收方式的选择及机构的设计提供理论依据.以山西省临汾市成熟期的大红袍花椒为试验对象,分别测定了花椒果实的压缩力学特性、穗柄的剪切力学特性、花椒果实与果柄连接处及穗柄的拉伸力学特性.结果表明,成熟期花椒的压缩、剪切、拉伸等力学特性指标值的变化范围:花椒果实受压的屈服载荷为31.40～66.34 N,平均屈服载荷为49.01 N;穗柄剪切力为2.18～5.58 N,平均剪切力为4.15 N,平均抗剪强度为1.60 MPa;穗柄抗拉力为5.03～15.04 N,平均抗拉力为8.60 N,平均抗拉强度为4.61 MPa;果实与果柄连接处抗拉力为2.30～4.83 N,平均抗拉力为3.86 N,显著小于穗柄抗拉力,平均抗拉强度为4.08 MPa.因此,机械采收花椒时机构作用在花椒果实上的压缩载荷应低于所测屈服载荷最小值31.40 N,否则会对花椒果实造成损伤;若采用剪切式采收方式,施加在穗柄处的剪切力应不低于2.18 N,采用负压等拉伸式采收方式应尽量选择在果实与果柄连接处进行分离采收.

A comb-type harvesting test bench was designed to address low fruit collection rate and theoretical analysis and simulation analysis of the harvesting process were carried out in this work. Single factor simulation experiment and bench experiment were carried out, and fruit collection rate was used as the evaluation index. The motor speed, bending angle of comb teeth and radial diameter of comb teeth arrangement were selected as the experimental factors. Results showed that the collection rate decreased with the increase of motor speed; and increased with the increase of the bending angle of comb teeth or the radial diameter of comb teeth arrangement. The orthogonal experiment of three-factor and three-level quadratic rotation centre combination was performed. The results showed that motor speed had the largest effect on collection rate, followed by radial diameter of comb teeth arrangement and bending angle of comb teeth. The optimal parameter combination was predicted by the response surface model as follows: motor speed of 25 r/min, bending angle of comb teeth of 120°, radial diameter of comb teeth arrangement of 868.45 mm and correspondingly the collection rate reached 91.51%. Based on actual harvesting efficiency and the machining problems of the test bench, the bench experiment was performed with the motor speed of 25 r/min, the bending angle of comb teeth of 120°, the radial diameter of comb teeth arrangement of 900 mm, and the collection rate was 93.82%. The relative error with the predicted optimal result was 2.48%, achieving the purpose of improving the collection rate.

针对胡麻分离清选过程高损失率、高含杂率问题,设计了风筛式胡麻清选装置.利用EDEM-Fluent耦合方法,对胡麻清选装置清选过程进行仿真分析,探究清选装置作业参数对胡麻籽粒含杂率和清选损失率的影响规律,确定最优的组合参数.基于清选装置气流场胡麻脱粒物料的运动分析,建立了胡麻清选装置简化模型;对风机风速、气流倾角、清选筛振动频率和振幅4个参数进行单因素试验和正交试验.结果 表明,风机风速、气流倾角、清选筛振动频率和振幅是影响清选装置清选性能的显著因素.应用Design-Expert软件建立了籽粒含杂率和清选损失率的数学回归模型,获得最佳工作参数组合:风机风速4.5 m/s、气流倾角4.、清选筛频率6 Hz、清选筛振幅9 mm,最优工作参数组合下胡麻籽粒含杂率为2.97％,清选损失率为2.39％.该研究结果可为胡麻清选装置的设计和优化提供参考.

[目的]对蓝亚麻蒴果离散元模型仿真参数进行标定.[方法]通过查阅文献法、物理试验法测定了蓝亚麻蒴果的基本物理参数(千粒质量、含水率、三轴尺寸、密度、泊松比、剪切模量)和接触力学参数(碰撞恢复系数、静摩擦系数和滚动摩擦系数)的取值或取值范围.以物理试验法测定的各参数为仿真试验参数选择依据,利用Minit-able18软件进行Plackett-Burman试验设计,对物理试验法粗测得的参数进行显著性筛选;进一步以实际休止角与仿真试验休止角的相对误差作为评价指标,对显著性参数进行最陡爬坡试验,通过仿真逼近预测法对显著性参数进行寻优.最后,以较优参数组合进行仿真试验验证,测得对应仿真试验休止角,并与实际休止角进行对比.[结果]Plackett-Burman试验结果表明:蓝亚麻蒴果间的滚动摩擦系数对仿真试验蒴果休止角影响显著;由最陡爬坡试验结果可得蓝亚麻蒴果间的滚动摩擦系数为0.18;仿真试验验证结果表明:仿真试验休止角与实际休止角相对误差为0.95％.[结论]应用上述各方法及优化试验来标定蓝亚麻蒴果离散元模型仿真参数是可行的.

针对钙果收获装置作业后钙果含杂率高的问题,设计了一种钙果风筛式清选装置.运用EDEM-Fluent耦合方法,以风速、振动筛振幅和振动频率为试验因素,钙果的清洁率和损失率为评价指标,对清选过程进行了仿真分析,并依据仿真结果进行台架试验.仿真分析与台架试验表明,随着风速、振动筛振动频率与振幅的增加,钙果清洁率先增大后减小,损失率一直增加.最优工作参数组合为风速10 m/s、振幅10 mm和振动频率9 Hz,最优工作参数组合条件下的钙果清洁率96.3％,损失率3.4％.研究表明,EDEM-Fluent耦合仿真的运用有助于钙果清选研究,研究结果可为钙果清选装置的设计与优化提供理论依据.

[目的]探索解决亚麻(胡麻)脱粒机存在的植株缠绕脱粒滚筒问题的有效方案,提升亚麻(胡麻)的机械化收获水平.[方法]为研究不同工作参数对亚麻(胡麻)机械化收获的影响,设计了梳齿式亚麻(胡麻)蒴果梳刷试验台.阐述该试验台的工作原理与组成结构,对关键零部件偏心摆动机构和梳刷装置进行了结构设计与动力学分析,并进行台架试验.以蓝亚麻(别名宿根亚麻)为试验材料,以蒴果的脱净率和破损率为评价指标,探讨梳刷装置转速、梳齿截面形状、梳齿间隙、导轨输送速度4因素对蒴果的脱净率和破损率的影响,分别进行单因素试验与多因素正交试验研究,获得了梳齿式亚麻(胡麻)蒴果梳刷试验台的最优工作参数,并进行了试验验证.[结果]SAS9.1软件分析表明:梳齿间隙、梳齿截面形状、梳刷装置转速和导轨输送速度4因素对蒴果的脱净率和破损率的影响都极为显著.以蒴果的脱净率较大、破损率较小为目标,得到的较优参数组合为:梳齿间隙为4mm、梳齿截面形状为菱形、梳刷装置转速为10 r/min和导轨输送速度为0.16 m/s.对优化结果进行试验验证,结果显示脱净率为99.26％,破损率为5.33％.各因素对脱净率的影响由大到小依次为梳齿间隙、梳齿截面形状、梳刷装置转速、导轨输送速度;对破损率的影响由大到小依次为导轨输送速度、梳齿截面形状、梳刷装置转速、梳齿间隙.[结论]蓝亚麻植株经过试验台的梳刷可得到完整蒴果,梳齿式亚麻(胡麻)蒴果梳刷试验台为亚麻(胡麻)脱粒机的创新设计提供了一种可行性方案和研究依据.

In this study, the changes of total flavonoids content in Cerasus Humilis fruits during storage periods were detected by using hyperspectral imaging (HSI) technique over the spectral region of 895-1,700 nm, and the spatial distribution of flavonoids was visualized during 24 days storage periods. The hyperspectral images of 240 samples of Cerasus Humilis were collected at different storage times (0, 8, 16, and 24 days). The Monte-Carlo outlier detection method was applied to identify four abnormal samples, three spectral preprocessing methods were used to preprocess the original spectral data, including savitzky-golay, standard normal variate, and baseline correction (BC). The x-loading weights, competitive adaptive reweighed sampling (CARS), uninformative variable elimination (UVE), UVE-CARS and the combination of UVE and successive projections algorithm (UVE-SPA) were used to reduce the dimension of spectral data and extract the characteristic wavelength, respectively. Then multiple linear regression and nonlinear least squared support vector machine (LS-SVM) regression models were developed based on full-spectrum data and selected characteristic wavelength. The results showed that BC was the best preprocessing approach, the LS-SVM models based on the nine effective wavelengths selected by UVE-CARS achieved the best results with correlation coefficient of prediction of .9357, root mean square error of prediction of 2.0107, and residual prediction deviation of 2.2809, respectively. The overall results demonstrated that the HSI technology coupled with chemometric algorithms is feasible to determine total flavonoids content, UVE-CARS-LS-SVM model was the optimal model. Visualization of the total flavonoids content during storage periods distribution map was performed, which clearly showed that the total flavonoids content kept decreasing with storage time. Practical Applications Cerasus Humilis is a fruit tree resource endemic to China. The content of total flavonoids is one of the key factors that affect the edible quality of Cerasus Humilis fruit. With the increase of storage time, the active components of flavonoids are easy to be degraded by oxidation, the quality and commercial value of Cerasus Humilis fruit were negatively affected. Thus, the detection of total flavonoids content during the storage of Cerasus Humilis fruit is of great significance. Traditional methods for determining total flavonoids content (such as the spectrophotometric techniques method) are mostly destructive, inefficient, time-consuming, and environmental pollution, which cannot meet the requirements of online monitoring of total flavonoids content. Hyperspectral imaging (HSI) technology has the advantages of rapid, nondestructive, accurate, and nonpollution. The results indicated that the HSI technology coupled with chemometric algorithms could be used to predict the changes of the total flavonoids content in Cerasus Humilis fruit during storage periods, which provided a theoretical basis for online and real-time monitoring of the quality of Cerasus Humilis fruit during storage.

In order to realize the rapid and non-destructive detection of fresh Cerasus Humilis’ (CH) classification, and promote the deep-processing of post-harvest fresh fruit and improve market competitiveness, this study proposed a nonlinear identification method based on genetic algorithm (GA) optimized back propagation (BP) neural network of different varieties of fresh CH fruit. “Nongda-4”, “Nongda-5”, and “Nongda-7” fresh CH fruit were selected as research objects to collect their visible/near-infrared spectral data dynamically. The original spectra were preprocessed by moving smoothing (MS) and standard normal variate (SNV) methods, for the characteristic wavelengths were extracted with four dimension-reducing methods, namely principal components analysis (PCA), competitive adaptive reweighed sampling (CARS), CARS-mean impact value (CARS-MIV), and random frog (RF) algorithm. Finally, the BP prediction models were established based on full-spectrum and characteristic wavelengths. At the same time, the GA optimization was used to optimize the initial weight and threshold of the BP neural network and compared with the partial least squares’ discrimination analysis (PLS-DA) linear model. Through comparing the MS (7)+SNV was proved to be the best preprocessing method, the CARS-MIV-GA-BP model had the best discriminant accuracy, the prediction set accuracy was 98.76%, of which the variety “Nongda-4” and “Nongda-5” recognition rate were 100%, the variety “Nongda-7” recognition rate was 96.29%. The results show that the GA can effectively optimize the initial weights and threshold randomization of the BP neural network, improve the discrimination accuracy of CH varieties, and the CARS-MIV algorithm can effectively reduce the number of input nodes of the BP neural network model, simplify the structure of BP neural network. This study provides a new theoretical basis for the detection of fresh CH fruit classification.