Wengang Zheng

National Engineering Research Center for Information Technology in Agriculture

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Daming Dong

Beijing Academy of Agricultural and Forestry Sciences

Leizi Jiao

Beijing Academy of Agricultural and Forestry Sciences

Xiande Zhao

Beijing Academy of Agricultural and Forestry Sciences

Chunjiang Zhao

National Engineering Research Center for Information Technology in Agriculture

Shirui Zhang

Institute of Rock and Soil Mechanics

Luyu Ding

National Engineering Research Center for Information Technology in Agriculture

Alan Gallagher

University of Colorado Boulder

Yinkun Li

Beijing Academy of Agricultural and Forestry Sciences

Weihong Ma

National Engineering Research Center for Information Technology in Agriculture

Jingxin Yu

Electric Power Research Institute

Cooperative Institutions

National Engineering Research Center for Information Technology in Agriculture

Beijing Academy of Agricultural and Forestry Sciences

University of Colorado Boulder

Chinese Academy of Sciences

Ministry of Agriculture and Rural Affairs

Laboratory for Atmospheric and Space Physics

China Agricultural University

Jiangsu University

National Central University

Zhejiang University

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Detection Method and Experimental Research of Leafy Vegetable Seedlings Transplanting Based on a Machine Vision

Agronomy (2022)

Wei Fu Jinqiu Gao Chunjiang Zhao Kai Jiang Wengang Zheng

In view of the need to remove empty cells and unqualified seedlings for automatic transplanting of leafy vegetable seedlings, this paper proposes a method to detect the growth parameters of leafy vegetable seedlings by using machine vision technology. This method uses the image processor PV200 to perform image grayscale, threshold segmentation, corrosion, expansion, area division, etc. to obtain the pixel value of the leaf area of the seedling and compare it with the set standard value, which provides guiding information for eliminating empty cells and unqualified seedlings. Lettuce seedlings at 17 days, 20 days, and 22 days of seedling age were used as the test objects, and the growth status and test results of the seedlings were analyzed to determine the optimum seedling age for transplanting. The test results show that there is basically no leaf cross-border between the lettuce seedlings at the age of 17 days, the average pixel area of the leaves is 3771.74, and the detection accuracy rate is 100%; the seedlings at the age of 22 days grow 5–6 leaves, the detection accuracy of unqualified seedlings and qualified seedlings was 62.50% and 88.16%, respectively, and the comprehensive detection accuracy was 85.71%. The comprehensive detection accuracy rate showed a downward trend with the increase of seedling age, mainly due to the partial occlusion between leaves. The transplanting of leafy vegetable seedlings is a sparse transplanting operation, and the seedling spacing increases after transplanting. Therefore, the detection of seedlings in the process of transplanting can greatly improve the recognition accuracy and solve the problem that the leaves of the seedlings in the seedling tray are obscured by each other and affect the detection accuracy. The research results can provide a theoretical basis and design reference for the development of the visual inspection system and the transplanting actuator of the leafy vegetable seedlings transplanting robot.

Transplanting

Machine Vision

Leafy vegetables

Leafy

10.3390/agronomy12112899

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Citations (8)

Determination of the mass transfer coefficient of ammonia emissions from dairy open lots using a scale model

Biosystems Engineering (2020)

Luyu Ding Qifeng Li Chaoyuan Wang Guoqiang Zhang Ruixiang Jiang

Volatilisation

Mass transfer coefficient

10.1016/j.biosystemseng.2019.12.008

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Citations (7)

Effects of irrigation scheduling on the yield and irrigation water productivity of cucumber in coconut coir culture

Scientific Reports (2024)

Y. Li Siqi Zhang Wenzhong Guo Wengang Zheng Qian Zhao

Optimum irrigation scheduling is important for ensuring high yield and water productivity in substrate-cultivated vegetables and is determined based on information such as substrate water content, meteorological parameters, and crop growth. The aim of this study was to determine a precise irrigation schedule for coconut coir culture in a solar greenhouse by comparing the irrigation, evapotranspiration (ET), substrate water content (VWC), as well as the crop growth indices and yield of cucumber, and irrigation water productivity (IWP) under three irrigation schedules: the soil moisture sensor-based method (T-VWC), the accumulated radiation combined with soil moisture sensor-based method (Rn-VWC), and the crop evapotranspiration estimated method using the hourly PM-ETo equation with an improved calculation of Kc (T-ETc). The results showed that the daily irrigation and evapotranspiration amount were the highest under T-VWC treatment, while the lowest under T-ETc treatment. In different meteorological environments, the change in irrigation amount was more consistent with the ET,and the VWC was relatively stable in T-ETc treatment compared with that under T-VWC or Rn-VWC treatments. The plant height, leaves number, leaf area, and stem diameter of T-VWC and Rn-VWC treatments were higher than those of the T-ETc treatments, but there was no significant difference in cucumber yield. Compared with the T-VWC treatment, total irrigation amount under Rn-VWC and T-ETc treatments significantly decreased by 25.75% and 34.04%, respectively ([Formula: see text]). The highest IWP values of 25.07 kg m[Formula: see text] was achieved from T-ETc treatment with significantly increasing by 44.33% compared to the T-VWC treatment (17.37 kg m[Formula: see text]). In summary, the T-ETc treatment allowed more reasonable irrigation management and was appropriate for growing cucumber in coconut coir culture.

Coir

Irrigation scheduling

10.1038/s41598-024-52972-x

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Citations (2)

Analyzing Strawberry Spoilage via its Volatile Compounds Using Longpath Fourier Transform Infrared Spectroscopy

Scientific Reports (2013)

Daming Dong Chunjiang Zhao Wengang Zheng Wenzhong Wang Xiande Zhao

The volatile compounds from fruits vary based on the spoilage stage. We used FTIR spectroscopy to analyze and to attempt to identify the spoilage process of strawberries. To enhance the sensitivity of the measuring system, we increased the optical pathlength by using multi-reflecting mirrors. The volatile compounds that were vaporized from strawberries in different spoilage stages were tested. We analyzed the spectra and found that the concentrations of esters, alcohols, ethylene and similar compounds changed with deterioration. The change patterns of the infrared spectra for the volatiles were further examined using 2D correlation spectroscopy. We analyzed the spectral data using PCA and were able to distinguish the fresh, slightly spoiled strawberries from the seriously spoiled strawberries. This study demonstrates that FTIR is an effective tool for monitoring strawberry spoilage and for providing status alerts.

Fourier transform spectroscopy

10.1038/srep02585

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Citations (47)

DualSPHysics simulations of spillway hydraulics: a comparison between single- and two-phase modelling approaches

Journal of Hydraulic Research (2022)

Shenglong Gu Wengang Zheng Haitao Wu Chen Chen Songdong Shao

This technical note presents the DualSPHysics application to spillway hydraulics, and an extensive comparison has been made between the single-water and two-phase water–air modelling approaches. It has been found that the DualSPHysics code based on the smoothed particle hydrodynamics method could provide a promising design tool for spillway flows in the engineering field. The model is first validated on a documented skimming flow and the numerical results are also compared with those computed from a smoothed spillway flow. Then the model is further validated by a laboratory experiment for a nappe flow, where the computed flow depth and velocity are validated against the physical measurements. It has been disclosed that for a skimming flow, the single- and two-phase SPH modelling approaches lead to small differences, while for a nappe flow with more serious free surface motion, the two-phase model clearly improved the simulation accuracy. After the model is fully validated, it is applied to investigate a practical spillway flow under different flow discharges, bed slopes and step numbers, covering two distinct spillway flow regimes. From the simulation results, the flow energy dissipation features are investigated with regards to the different flow rates and spillway configurations. It has been found that the energy dissipation efficiency of a spillway is proportional to the number of the steps but inversely proportional to the flow discharge and the spillway slope.

Spillway

Hydraulics

10.1080/00221686.2022.2064343

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Citations (19)

Numerical investigation on effects of side curtain opening behavior on indoor climate of naturally ventilated dairy buildings

International journal of agricultural and biological engineering (2020)

Qifeng Li Chuanxia Yao Luyu Ding Ligen Yu Weihong Ma

The side-curtain is popular in cattle buildings to regulate indoor climates and ventilation rates by adjusting the opening ratio. It normally had three different adjusting strategies relate to the position of rollers, i.e. central roller (S1), top roller (S2) and bottom roller (S3), which result in different opening behaviors to generate the same opening ratio but different opening positions in the side wall for a full-curtain house. Numerical simulations were conducted using computational fluid dynamics (CFD) to investigate the effects of the eight potential opening behaviors of side curtains on the indoor climates and airflow rates in winter for a typical naturally ventilated dairy house in China when the opening ratio were 8.5% and 17%. Airflow patterns, wind chilled temperature (WCT) and age of air were analyzed in the animal occupied zone (AOZ) by taking reference planes. Openings at the very bottom of side walls had more efficient ventilation due to the younger air age, more effective air disturbing, more uniformly distributed indicators in AOZ. However, it will result in a lower WCT in AOZ although a lower ventilation rate was observed in this case. Openings on the very top of side wall would generate a better thermal comfort in AOZ but with very poor air quality and nonuniformly distributed airflows in the dairy house. S1 was not recommended to the practical application due to the poor indoor climate and the higher cost of the mechanical structure. Based on the comprehensive evaluations of the analytic hierarchy process, the most satisfaction opening positions were at the bottom of the side curtains and the optimized adjusting strategy is S2. Keywords: thermal comfort, age of air, ventilation rate, computational fluid dynamics, analytic hierarchy process DOI: 10.25165/j.ijabe.20201305.5805 Citation: Li Q F, Yao C X, Ding L Y, Yu L G, Ma W H, Gao R H, et al. Numerical investigation on effects of side curtain opening behavior on indoor climate of naturally ventilated dairy buildings. Int J Agric & Biol Eng, 2020; 13(5): 63–72.

Curtain wall

Natural Ventilation

10.25165/j.ijabe.20201305.5805

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Citations (5)

A Hybrid Prediction Model for CatBoost Tomato Transpiration Rate Based on Feature Extraction

Agronomy (2023)

Zhaoyang Tong Shirui Zhang Jingxin Yu Xiaolong Zhang Baijuan Wang

The growth and yield of crops are highly dependent on irrigation. Implementing irrigation plans that are tailored to the specific water requirements of crops can enhance crop yield and improve the quality of tomatoes. The mastery and prediction of transpiration rate (Tr) is of great significance for greenhouse crop water management. However, due to the influence of multiple environmental factors and the mutual coupling between environmental factors, it is challenging to construct accurate prediction models. This study focuses on greenhouse tomatoes and proposes a data-driven model configuration based on the Competitive adaptive reweighted sampling (CARS) algorithm, using greenhouse environmental sensors that collect six parameters, such as air temperature, relative humidity, solar radiation, substrate temperature, light intensity, and CO2 concentration. In response to the differences in crop transpiration changes at different growth stages and time stages, the t-Distributed Stochastic Neighbor Embedding (t-SNE) algorithm was used to identify three characteristic intervals: florescence stage, fruiting stage daytime, and fruiting stage night-time. Based on this, a greenhouse tomato Tr prediction model (CARS-CatBoost model) based on the CatBoost machine learning algorithm was constructed. The experimental verification shows that the coefficient of determination (R2) of the constructed CARS-CatBoost single model for the whole growth stage is 0.92, which is higher than the prediction accuracy of the traditional single crop coefficient model (R2 = 0.54). Among them, the prediction accuracy at night during the fruiting stage is the highest, and the Root Mean Square Error (RMSE) drops to 0.427 g·m−2·h−1. This study provides an intelligent prediction method based on the zonal modeling of crop growth characteristics, which can be used to support precise irrigation regulation of greenhouse tomatoes.

Light intensity

10.3390/agronomy13092371

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Citations (1)

An Olfaction Monitoring System for Malodorous Gases

Applied Engineering in Agriculture (2013)

Shi-Rui Zhang Jihua Wang Daming Dong Wengang Zheng Xiande Zhao

<italic>Abstract. </italic> Malodorous gases in animal housing are harmful to human being and animals and extremely difficult to measure. In this work, constant potential electrochemical sensors were used to establish an olfaction monitoring system for animal housing. The system can give an odor level index value based on the concentrations of ammonia and hydrogen sulfide. The system consists of an electrochemical sensor, signal conditioning circuit, data acquisition module, and signal processing unit. The working principle of the system is described in this article. As for hardware and software design solutions, we introduced the details of each module. In addition, we discussed the calibration methods and odor level index determination method. The validation experiment proved that the concentrations of ammonia and hydrogen sulfide could reflect the odor level index in swine building. In the control test, we compared the results of olfactometry with the results of the system. The comparative experiment showed that coincidence rate of the system with the olfactometry was 76.2% with the testing error of less than 1 level. The malodorous gas olfaction monitoring system allows real-time measurement of the malodorous gases in the swine building.

SIGNAL (programming language)

10.13031/aea.29.9846

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Citations (1)

Water Utilization Strategy of Tomato Grown on East-West Ridges in Solar Greenhouses Revealed Based on Hydroxide Isotopes

Furong Han Lili Zhangzhong Wengang Zheng Jingjing Li Kaili Shi

Solar greenhouse

10.2139/ssrn.4991966

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Citations (0)

Waterworks comprehensive monitoring management system design based on T-S model

Advances in engineering research/Advances in Engineering Research (2016)

Yan Bai Wengang Zheng

This paper designs a set of PLC technology, network information technology, configuration technology in the integrated monitoring and management system, which has the advantages of unified management, reasonable open source, optimizing the configuration and overall saving.In the process of water treatment, T-S model and PID algorithm are combined to solve the problem of nonlinear and time delay.

Network monitoring

10.2991/icmmct-16.2016.1

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Citations (0)