Experimental Study on Tensile Properties of Sugarcane Leaves

Highlights This article focuses on the tensile properties of sugarcane leaves. The moisture content and sheath diameter were selected as test factors, and the test index was the stalk-leaf connecting force. The load-displacement curves of stalks and leaves were plotted. Two-way ANOVA was also discussed. Abstract . The tensile properties of sugarcane leaves are critical factors affecting the harvesting quality of sugarcane harvesters. Thus, it is important to investigate the tensile properties of sugarcane stalks and leaves. The selected test factors were leaf moisture content and sheath diameter, and the stalk-leaf connecting force was selected as test index. The tests were conducted with two moisture content levels of 15% and 20%, and three sheath diameters of 22, 26, and 30 mm. The stress-strain curves of stalks and leaves were plotted to show how the tensile force varied during the tensile test. The results showed that there was a strong linear correlation between the stalk-leaf connecting force and diameter of leaf sheath, and the connecting force also increased with the increasing moisture content. In addition, leaf tensile forces in longitudinal direction were much larger than in transverse direction. Two-way ANOVA revealed that both of the moisture contents (A) and sheath diameters (B) had significant effects on the stalk-leaf connecting force (p < 0.01), however, the interaction between A and B was not significant (p > 0.1). This study provides a theoretical reference for the design and improvement of crop dividers of sugarcane harvester. Keywords: Moisture content, Sheath diameter, Stalk-leaf connecting force, Sugarcane leaves, Universal testing machine, Tensile properties.

Effects of Moisture Content and Compaction Pressure on Bulk Density of Rye

HighlightsRye grain compaction was measured for three different moisture contents (8%, 12%, and 16% wet basis) at five different compaction pressures (7, 14, 34, and 55 kPa)Bulk densities were found to be statistically significantly dependent (p < 0.0001) on both the moisture content and applied pressure.Compacted bulk densities increased with increasing applied pressure for all moisture contents.Abstract. Bulk density of agricultural grains is needed to determine the quantity of grain in storage structures and to calculate grain pressures. The objective of this study was to investigate the effects of moisture content and applied pressure on bulk density of rye grain at moisture contents and pressures typical of those seen in storage structures. Rye compaction was measured for three moisture contents (8%, 12%, and 16% wet basis) at four compaction pressures (7, 14, 34, and 55 kPa) using a square box (based on the design used by Thompson and Ross, 1983). Data from the compaction tests were used to calculate the bulk densities for the three moisture contents and four compaction pressures. The bulk densities were found to be significantly dependent (p <0.0001) both on moisture contents and the pressure applied. Bulk densities varied with increasing moisture content as has been observed in similar studies for rye and other agricultural grains such as wheat and soybeans. These results provide guidance for estimating bulk density of rye in bins and other storage structures. Keywords: Grain compaction, Grain storage, Kernel rearrangement, Kernel elasticity.

Portable Wireless Yield Monitoring System on Conventional Rice Combine

A simple, portable, and rugged instrumentation system has been successfully developed and field demonstrated to monitor, measure, and record the harvested crop yield and selected machine field performance parameters from the typical rice combines in Malaysia. The complete system comprises of two ultrasonic sensors located at the combine header to measure the cutting width, microwave solid flow, and microwave moisture sensors at the combine clean grain auger to measure the flow rate and moisture content of the cleaned grains going into the grain tank, electromagnetic detector on the combine grain elevator drive shaft to monitor the grain elevator rotational speed, and lastly a DGPS receiver on the combine console roof to indicate the travel speed and geo-position in the field. All these measured parameters were made to display in-real time on the touch panel screen of the embedded system on-board the combine for the interest of the combine operator and also made to display in-real time on the monitor of the toughbook at the on-ground base station for the interest of the system controller. Static calibrations on the individual sensors showed excellent measurement linearity having R2 values within 0.8760 to 1.000 ranges. The wireless communication between the embedded system on-board the combine and the toughbook at the on-ground base station could be sustained to a maximum distance of 185 m apart. Site specific variability maps of crop yield, harvested grain moisture content, combine cutting width, combine traveling speed, combine field capacity, and combine field efficiency within the harvested area could be produced from the data obtained with the instrumentation system using a GIS software. Keywords: Grain harvesting, Paddy mechanization, Precision farming, Wireless data transmission, Yield monitoring.

Research and Experiment on Path-Tracking Control of Autonomous Tractor Based on Lateral Deviation and Yaw Rate Feedback

HighlightsAutomatic navigation technology in autonomous tractors is one of the key technologies in precision agriculture.A path-tracking control algorithm based on lateral deviation and yaw rate feedback is proposed.The modified steering angle was obtained by comparing the ideal yaw rate with the actual yaw rate.The results demonstrate the efficiency and superior accuracy of the proposed algorithm for tractor path-tracking control.Abstract. The performance of path-tracking control systems for autonomous tractors affects the quality and efficiency of farmland operations. The objective of this study was to develop a path-tracking control algorithm based on lateral deviation and yaw rate feedback. The autonomous tractor path lateral dynamics model was developed based on preview theory and a two-degree-of-freedom tractor model. According to the established dynamic model, a path-tracking control algorithm using yaw angular velocity correction was designed, and the ideal steering angle was obtained by lateral deviation and sliding mode control. The modified steering angle was obtained by a proportional-integral-derivative feedback controller after comparing the ideal yaw rate with the actual yaw rate, which was then combined with the ideal steering angle to obtain the desired steering angle. The simulation and experimental results demonstrate the efficiency and superior accuracy of the proposed tractor path-tracking control algorithm, enabling its application in automatic navigation control systems for autonomous tractors. Keywords: Autonomous tractor, Path-tracking control, Sliding mode control, Yaw rate feedback.

An Open-Sourced Web Application for Aerial Applicators to Avoid Spray Drift Caused by Temperature Inversion

HighlightsA web application for guiding data calculated from distributed weather data through open-source cloud service.A design scheme of portable weather stations built from inexpensive open-source electronics.Integration of open-source hardware and software for online guiding data to avoid drift caused by temperature inversion.Abstract. It is important for agricultural chemical applicators to follow proper spray procedures to prevent susceptible crops, animals, people, or other living organisms from being injured far downwind. Spraying during stable atmospheric conditions should be avoided to prevent surface-temperature inversion-induced off-target drift of crop protection materials. Previous statistical analysis determined times of high likelihood of stable atmospheric conditions, which are unfavorable for spraying, during the day under clear and cloudy conditions in hot summer months in the Mississippi Delta. Results validated the thresholds of temperature increase in the morning and temperature drop in the afternoon with wind speeds and the transition between stable and unstable atmospheric conditions. With this information, an algorithm was developed to calculate if atmospheric conditions were favorable for spraying based on field temperature and wind speed at any instant. With this algorithm, a web application was built to provide real-time determination of atmospheric stability and hourly online recommendation of whether aerial applications were appropriate for a location and time in the Mississippi Delta. This study further developed another web application specifically for Stoneville, Mississippi, with data measured from weather stations constructed from inexpensive open-source electronics, accessories, and software for more accurate online guidance for site-specific drift management. The web application is adapted for accessing on mobile terminals, such as smartphones and tablets, and provides timely guidance for aerial applicators and producers to avoid spray drift and air quality issues long distances downwind in the area. Keywords: Open-source hardware, Open-source software, Spray drift, Temperature inversion, Web application.

Growth Characteristics of Summer Cover Crop Grasses and their Relation to Soil Aggregate Stability and Wind Erosion Control in Arid Southwest

HighlightsFour summer cover crops under two irrigation regimes were tested for soil wind erosion control.Soil aggregate stability and wind erosion losses were improved with plant cover in the peak summer.Sorghum sudan is a prominent summer species for wind erosion control in the arid southwest. Abstract. Cover crops can have significant impacts on minimizing soil erosion by wind, which is a common problem in the arid southwest. A study was conducted at NMSU Leyendecker Plant Science Center, Las Cruces, New Mexico, to evaluate the impacts of selected summer cover crops on soil loss during wind erosion events. Four summer grass species [Japanese millet (Echinochloa esculenta), pearl millet (Pennisetum glaucum), brown top millet (Urochloa ramosa (L.) Nguyen), and sorghum sudangrass (Sorghum bicolor × S. bicolor var. Sudanese)] were randomly assigned to four blocks under two irrigation regimes (full-irrigation and deficit-irrigation). Results showed significant effect of grasses on horizontal soil flux compared to control under both irrigation regimes. When comparing the grasses, sorghum sudan grass performed better than the other tested summer cover crops for soil surface protection from wind erosion with its higher ground coverage, higher plant density, taller plant height and higher amount of biomass, while brown top millet was least effective in terms of plant and erosion control characteristics (P=0.05). Pearl millet and Japanese millet performed better than brown top millet, but was as effective as sorghum sudan as barriers against the wind erosion. Therefore, sorghum sudan is a prominent cover crop for summer in the arid zones of desert southwest. Producers of this region can be significantly benefited from the current research recommendations about cover crops choices for summer season. Keywords: Arid climates, Cover cropping, Summer grasses, Wind erosion control.

Optimal Design of Photovoltaic Irrigation System with Different Nozzle Numbers

HighlightsWhen the photovoltaic irrigation system is loaded with different numbers of nozzles, the working pressure of the nozzle will change. This is because the pipeline characteristics have changed with the variation of nozzle number. So the pump operating point changes and its head will also change, which leads to the change of working pressure of nozzle. To solve this problem, by theory analysis based on the test results, it is feasible to make the pump flow rate/head curve flatter. In this case, when the system pipeline characteristics change, the pump head changes little.This article presents a new optimization method to improve the performance of photovoltaic irrigation systems under variable load. The method just needs to optimize the four pump impeller structure parameters, which can make the pump flow rate/head curve flatter. So the pump head changes a little when the system is loaded with different numbers of nozzles, which can make the working pressure of the nozzle stable and improve the system performance.Taking the slope of flow-head curve as the optimization objective, and the impeller blade outlet angle ß2, blade outlet width b2, blade number Z, and rear cover diameter D2min as the optimization variables, the performance of the photovoltaic irrigation system is optimized by orthogonal test design optimization scheme. After optimization, when the system is loaded with a different number of nozzles, it can provide relatively similar pressure under different ranges of light intensity.Abstract. The performance of the photovoltaic irrigation system under variable load were obtained and analyzed through test measurement. The adaptability of the system under variable load could be improved by optimizing the pump impeller structure, and then the irrigation uniformity of the photovoltaic irrigation system under different loads could be improved. Taking the slope of flow-head curve as the optimization objective, and the impeller blade outlet angle ß2, blade outlet width b2, blade number Z, and rear cover diameter D2min as the optimization variables, the performance of the photovoltaic irrigation system is optimized by orthogonal test design optimization scheme and the test verification was carried out. The range method was applied to analyze the simulation results. It can be found that when the geometric parameters of the impeller are D2 = 86 mm, ß2 = 41°, b2 = 4.0 mm, and Z = 9, the slope of the pump flow-head curve is the highest. The system performance after optimization was measured and compared with the original scheme. By comparison, it was drawn that when the system is loaded with different numbers of nozzles, the nozzle pressure can be maintained near the optimal pressure of the nozzle within a wider light intensity. After optimization, when the system is loaded with a different number of nozzles, it can provide relatively similar pressure under different ranges of light intensity. Keywords: Nozzle, Orthogonal test, Optimal design, Photovoltaic irrigation, Pump.

River Dissolved Oxygen Prediction Based on Random Forest and LSTM

HighlightsRandom Forest (RF) and LSTM were developed for river DO prediction.PH is the most important feature affecting DO prediction.The model base on RF is better than the model not on RF, and the dimensionality of the input data is reduced by RF.RF-LSTM model is outperformed SVR, RF-SVR, BP, RF-BP, LSTM, RNN models in DO prediction.Abstract. In order to improve the prediction accuracy of dissolved oxygen in rivers, a dissolved oxygen prediction model based on Random Forest (RF) and Long Short Term Memory networks (LSTM) is proposed. First, the Random Forest performs feature selection, which reduces the input dimension of the data and eliminates the influence of irrelevant variables on the prediction of dissolved oxygen. Then build the LSTM river dissolved oxygen prediction model to fit the relationship between water quality data and dissolved oxygen, and finally use real water quality data in the river for verification. The experimental results show that the mean square error (MSE), absolute error (MAE), mean absolute percentage error (MAPE), root mean square error (RMSE), and coefficient of determination (R2) of the RF-LSTM model are 0.658, 0.528, 13.502, 0.811, 0.744, respectively, which are better than other models. The RF-LSTM model has good predictive performance and can provide a reference for river water quality management. Keywords: Dissolved oxygen prediction, LSTM, Random forest, Time series, Water quality management.

Indoor Climate and Energy Model Calibration with Monitored Data of a Naturally Ventilated Dairy Barn in a Cold Climate

HighlightsIndoor climate and energy model of a dairy barn is constructed and calibrated with collected data.Long-term monitoring of indoor conditions and electricity consumption greatly facilitates the model calibration process.Statistical benchmarks given by guidelines confirm the usability and reliability of the model.Abstract. This study demonstrates an application of ICE model calibration by using sensor building metrics in a naturally ventilated dairy house in a cold climate. The barn, at the time of the study, had 70 lactating cows and 30 calves with a total animal area of 1922 m2 and other auxiliary areas of 268 m2. Indoor condition data were collected by four integrated sensors inside the barn for six months, from March to August 2019. IDA ICE 4.8 SP1 simulation software was used to build and simulate the model, with calibration steps conducted first manually, then statistically. Actual weather and indoor condition data during the monitored period were used for calibration; statistical indices of the calibrated model were confirmed by the benchmarks given from ASHRAE Guideline 14-2014, IPMVP version 2016, and FEMP version 4.0 2015. The yielded result was a baseline ICE model, which can be further utilized in the study of energy conservation measures (ECMs), retrofitting feasibility, and ammonia and other contaminant gas emission mitigation. The abovementioned calibration practice and the proposals built on it open a pathway to achieve a higher level of energy efficiency for this type of livestock building. Keywords: Cold weather, Dairy farms, Model calibration, Natural ventilation.