Transactions of the ASABE最新文献

{"title":"A Proposed Method for Quantifying Thermal Exposure Incurred during Rough-Rice Drying","authors":"S. Graham‐Acquaah, T. Siebenmorgen","doi":"10.13031/TRANS.14063","DOIUrl":"https://doi.org/10.13031/TRANS.14063","url":null,"abstract":"HighlightsDrying conditions affect rice end-use functionality.Thermal exposure incurred by rough rice may differ depending on drying conditions.A framework is proposed for deriving an index that can show how much heat exposure rough rice incurs during drying.Abstract. Heated air is used to dry most rice in the U.S. Thus, commercial rice drying can be considered a thermal process that aims to remove moisture from rough rice until a desired moisture content is reached. Parallels can be drawn between rice drying and thermal sterilization that is targeted at reducing microbial load because moisture content reduction during drying follows similar decay rate kinetics as the reduction in microbial load during thermal sterilization. Given the different combinations of drying air conditions (air temperature and relative humidity), as well as drying and tempering durations, employed in various dryer designs for rice drying and the impact that these conditions have on rice end-use functionality, this study sought to derive a thermal treatment index (drying process values) that is similar to the F0 value concept used in thermal sterilization for quantifying and comparing the thermal exposure incurred by rice during drying under various scenarios. Using data collected from rough-rice drying experiments, a decimal desorption value (Dmv) that represents the duration required to cause a 90% reduction in moisture ratio during drying at a specified temperature was determined, from which a thermal desorption constant (Zmv) that represents the increase in temperature necessary to cause a 90% reduction in Dmv during drying was established. Subsequently, a thermal desorption value (Fmv) was derived to express the duration that a rice lot would have been heat treated at a reference temperature during drying to produce an equivalent effect on moisture content as that produced by the actual drying process. Keywords: End use, Moisture content, Peak viscosity, Postharvest, Relative humidity, Rice, Temperature.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74560343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of a Robotic Harvesting Mechanism for Button Mushrooms","authors":"Mingsen Huang, Xiaohu Jiang, Long He, D. Choi, J. Pecchia, Yaoming Li","doi":"10.13031/TRANS.14194","DOIUrl":"https://doi.org/10.13031/TRANS.14194","url":null,"abstract":"HighlightsA robotic mushroom picking mechanism was developed, including positioning, picking, and stipe trimming.The picking end-effector was designed based on a bending motion around the stipe-substrate joint.The overall success rate of the developed picking mechanism reached 91.4%.Acting time and air pressure for the suction cup were studied in mushroom bruise level tests.Abstract. Button mushroom (Agaricus bisporus) harvesting mainly relies on costly manpower, which is time-consuming and labor-intensive. Robotic harvesting is an alternative method to address this challenge. In this study, a robotic mushroom picking mechanism was designed, including a picking end-effector based on a bending motion, a four degree-of-freedom (DoF) positioning end-effector for moving the picking end-effector, a mushroom stipe trimming end-effector, and an electro-pneumatic control system. A laboratory-scale prototype was fabricated to validate the performance of the mechanism. Bruise tests on the mushroom caps were also conducted to analyze the influence of air pressure and acting time of the suction cup on bruise level. The test results showed that the picking end-effector was successfully positioned to the target locations. The success rate of the picking end-effector was 90% at first pick and increased to 94.2% after second pick. The main reason for the failures was inclined growing condition of those mushrooms, resulting in difficulties in engaging the mushroom cap with the suction cup facing straight downward. The trimming end-effector achieved a success rate of 97% overall. The bruise tests indicated that the air pressure was the main factor affecting the bruise level, compared to the suction cup acting time, and an optimized suction cup may help to alleviate the bruise damage. The laboratory test results indicated that the developed picking mechanism has potential to be implemented in automatic mushroom harvesting. Keywords: Bruise test, End-effector, Mushroom, Robotic harvesting.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80900855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating Daily CO2 Concentrations in SWAT-VSA to Examine Climate Change Impacts on Hydrology in a Karst Watershed","authors":"K. M. Gunn, A. Buda, H. Gall, R. Cibin, C. Kennedy, T. Veith","doi":"10.13031/TRANS.13711","DOIUrl":"https://doi.org/10.13031/TRANS.13711","url":null,"abstract":"Abstract. Highlights We used SWAT-VSA to assess the effects of climate change with rising CO2 on the water balance of a karst basin. For future climate, SWAT-VSA with rising CO2 yielded 7.1% less ET and 6.3% more runoff than standard SWAT-VSA. Rising CO2 also affected variable source areas, with greater ET declines and runoff increases in the wettest soils. Findings suggest CO2 effects on water balance should be included in future climate change studies with SWAT-VSA. Characterizing the effects of climate change on hydrology is important to watershed management. In this study, we used SWAT-VSA to examine the effects of climate change and increasing atmospheric CO2 (CO2) on the water balance of Spring Creek watershed, a mixed land-use karst basin in the Upper Chesapeake Bay watershed. First, we modified the stomatal conductance and leaf area index (LAI) routines of SWAT-VSA‘s Penman-Monteith evapotranspiration (ET) procedure and enabled the model to accept daily CO2 data. Using downscaled climate projections from nine global climate models (GCMs), we then compared water balance estimations from baseline SWAT-VSA against two modified versions of SWAT-VSA. One SWAT-VSA version integrated daily CO2 levels (SWAT-VSA_CO2), while another version added flexible stomatal conductance and LAI routines (SWAT-VSA_CO2+Plant) to the dynamic CO2 capacity. Under current climate (1985–2015), the three SWAT-VSA models produced generally similar water balance estimations, with 51% of precipitation lost to ET, and the remainder converted to runoff (10%), lateral flow (9%), and percolate (30%). For future climate (2020–2065), water balance simulations diverged between baseline SWAT-VSA and the two modified SWAT-VSA models with CO2. Notably, variable stomatal conductance and leaf area index (LAI) routines produced no detectable effects beyond that of CO2. For the 2020–2065 period, baseline SWAT-VSA projected ET increases of 0.7 mm yr-1, while SWAT-VSA models with CO2 suggested annual ET could decline by approximately -0.4 mm yr-1 over the same period. As a result, the two CO2-based SWAT-VSA models predicted streamflow increases of almost 1.6 mm yr-1 over the 2020–2065 period, which were roughly double the streamflow increases projected by baseline SWAT-VSA. In general, SWAT-VSA models with CO2 effects produced 22.4% more streamflow in 2045–2065 than the SWAT-VSA model without CO2. Results also showed that adding daily CO2 to SWAT-VSA reduced ET in wetter parts of the Spring Creek watershed, leading to greater runoff losses from variable source areas compared to baseline SWAT-VSA. Findings from the study highlight the importance of considering increasing atmospheric CO2 concentrations in water balance simulations with SWAT-VSA in order to gain a fuller appreciation of the hydrologic uncertainties with climate change.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81062614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of Soil Moisture Sensing Technologies in Silt Loam and Loamy Sand Soils: Assessment of Performance, Temperature Sensitivity, and Site- and Sensor-Specific Calibration Functions","authors":"K. Sharma, S. Irmak, M. Kukal, M. Vuran, A. Jhala, Xin Qiao","doi":"10.13031/trans.14112","DOIUrl":"https://doi.org/10.13031/trans.14112","url":null,"abstract":"Reliable soil moisture information is vital for optimal irrigation management, farm-level agronomic decisionmaking, hydrologic studies, and cropping systems modeling. A wide range of soil moisture sensing technologies is commercially available, but their performance must be evaluated for diverse conditions of use. In this research, we investigated nine soil moisture sensors based on time-domain reflectometry, capacitance, and electrical resistance principles in production field conditions with two installation orientations, i.e., vertical (V) and horizontal (H), in two soils (silt loam and loamy sand) and two growing seasons (2017 and 2018). Performance parameters deduced from the 2017 datasets revealed that sensor type and soil type significantly affected the soil moisture sensor performance under factory calibration (F.C.); however, sensor installation orientation did not. Thus, the sensors were only evaluated based on their performance in horizontal orientation in both soils. Precision and accuracy were considered targets to assist in appropriate sensor selection. To improve sensor accuracy, site-specific calibration (S.S.C.) functions were developed and validated using independent datasets from 2018. Considering mean bias error (MBE), all sensors overestimated volumetric soil water content (v) in both soils, with the exception of TEROS 21 (MPS-6) in silt loam and JD probe in loamy sand. On average, sensor performance was 67% better in loamy sand than in silt loam. Overall, the sensors showed higher precision in silt loam (R2 = 0.53 to 0.93) than in loamy sand (R2 = 0.25 to 0.82). Substantial post-S.S.C. improvement (32% to 89%) was observed in all sensors’ performance relative to F.C. in silt loam. In loamy sand, while most sensors performed reasonably well with F.C., considerable improvements (28% to 85%) were observed with S.S.C. Significant differences (p < 0.05) were observed in sensors’ sensitivity to soil temperature (Tsoil), which ranged from 14°C to 23°C in silt loam and from 14°C to 25°C loamy sand during the experiments. The CS655, 10HS, 5TE, and TEROS 21 (MPS-6) sensors showed significant (p < 0.05) sensitivity to Tsoil fluctuations, with Tsoil explaining a maximum of 17% of the variance observed in sensor performance. No statistically significant (p > 0.05) sensitivity was detected for any of the sensors in loamy sand. TEROS 21 (MPS-6) had the highest sensitivity to Tsoil with a slope of -4.25. In contrast, while statistically significant (p < 0.05), 5TE was the least sensitive to Tsoil variability with a slope of 1.81. The information, data, and analyses presented here can be instrumental for informed sensor selection and use in decision-making in production fields with similar soil textures and soil water regimes.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81226173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Development of a GIS-Based Framework to Locate Biomass and Municipal Solid Waste Collection Points for an Optimal Waste Conversion Facility","authors":"Prashant Patel, M. Vaezi, R. Sebastian, Amit Kumar","doi":"10.13031/trans.14253","DOIUrl":"https://doi.org/10.13031/trans.14253","url":null,"abstract":"HighlightsAn integrated GIS-based tool was developed for optimally locating bioenergy facilities.Waste and lignocellulosic biomass potential and distribution were assessed for Alberta.A case study for Alberta’s Industrial Heartland identified facility locations for two scenarios.Ten optimal locations were identified across Alberta for bioconversion of waste and biomass feeds.Abstract. Quantifying the availability of feedstock and determining an optimal location are key to ensuring the sustainability of a waste to value-added (W2VA) facility. This study aims to identify lignocellulosic biomass (agricultural and forest residues) and municipal solid waste (MSW) potential, find geographical point-source locations for the distributed biomass, and identify optimal locations for W2VA facilities across the province of Alberta, Canada, using an integrated geographic information system (GIS) based approach. MSW potential is estimated using population and average annual waste generation per capita, while agriculture and forest residue are estimated using production data and harvesting residue factor. A GIS-based framework is developed to locate biomass collection points by latitude and longitude for distributed biomass and to estimate their associated biomass potential. An integrated framework is subsequently developed to optimally locate W2VA facilities that have minimal environmental, economic, and social impacts. An array of geographical constraints is then considered in a suitability analysis and network analysis framework. An estimate of the annual availability of feedstock using the most recent data shows MSW, agricultural residue, and forest residue potentials of 4,330,000 wet megagrams (Mg), 4,060,000 dry Mg, and 2,070,000 dry Mg, respectively, in Alberta. Optimal W2VA facility locations are identified for Alberta’s Industrial Heartland (AIH) considering waste heat from the areas as an additional energy source. Ten other locations where facilities can be operated sustainably are identified across the province. This study can be used as a framework by municipalities and communities in any jurisdiction in the world to geographically locate biomass source and collection points, along with their annual capacity, and the corresponding optimal site for a W2VA facility. Keywords: Biomass, Biorefinery, GIS, suitability analysis, Integrated methodology, Municipal solid waste, Sustainability, Waste management, Waste-to-energy.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77739500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ammonia Concentrations and Emissions at Two Commercial Manure-Belt Layer Houses with Mixed Tunnel and Cross Ventilation","authors":"Xinjie Tong, Lingying Zhao, R. Manuzon, M. Darr, R. M. Knight, Chaoyuan Wang, A. Heber, J. Ni","doi":"10.13031/trans.14634","DOIUrl":"https://doi.org/10.13031/trans.14634","url":null,"abstract":"HighlightsAnnual average NH3 concentrations in two retrofitted manure-belt layer houses were 4.0 ±3.3 and 5.2 ±3.0 ppmv.Seasonal and diurnal variations were observed for NH3 concentrations (higher in colder seasons and early morning).Annual average NH3 emission rates from the two layer houses were 0.081 ±0.004 and 0.099 ±0.004 g d-1 hen-1.No consistent pattern was found for either seasonal or diurnal variations in NH3 emission rates.Abstract. Ammonia emission measurements at poultry houses are necessary to assess air quality and emission factors associated with poultry operations, but no data have been reported for manure-belt layer houses retrofitted from high-rise layer houses. Two commercial retrofitted manure-belt layer houses (both 121.9 m long, 19.5 m wide, and 7.7 m high; 170,000 bird nominal capacity each) in Ohio with mixed usage of tunnel and cross ventilation systems were continuously monitored for one year. The daily averages of the exhaust NH3 concentrations varied from 0.03 to 17.7 ppmv in house 1 and 0.37 to 14.4 ppmv in house 2 with annual means (±SD) of 4.0 ±3.3 and 5.2 ±3.0 ppmv, respectively. The NH3 emission factors based on the full year of data for houses 1 and 2 were 0.081 ±0.004 and 0.099 ±0.004 g d-1 hen-1 (12.5 ±10.1 and 15.2 ±10.6 kg d-1 house-1 or 24.9 ±20.0 and 31.1 ±23.4 g d-1 AU-1), respectively. Seasonal variations were observed for NH3 concentrations, with higher concentrations in winter and lower concentrations in summer. Within a day, NH3 concentrations were highest from 4:00 to 8:00 and lowest from 16:00 to 20:00. No consistent pattern was observed for seasonal or diurnal variations of NH3 emission rates. Higher NH3 concentrations and emissions were observed at the east and west exhaust air streams of the houses compared to the north and south exhaust air streams due to the unique configuration of the ventilation systems. NH3 emission was correlated with exhaust absolute humidity, hen caloric intake, feed consumption, and protein percentage of feed. Keywords: Ammonia emission factor, Diurnal variation, High-rise, Retrofitted poultry house, Seasonal variation, Spatial variation.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81192719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Intelligent Carbon Fiber Heater on Pig Behavior, Production Performance, and Energy Consumption","authors":"Li Xiusong, Zhangying Ye, Guo-Qun Li, Pan Shen, Songming Zhu, Zhao Shiguang, Dezhao Liu, Zhang Jie, Shen Zhongyin, Gao Weiwei","doi":"10.13031/TRANS.14104","DOIUrl":"https://doi.org/10.13031/TRANS.14104","url":null,"abstract":"HighlightsIntelligent carbon fiber heaters (ICFH) increased the tendency of sows to expose their udders toward the heating area.During the first week after birth, piglets with ICFH used the heating area more frequently and spent less time in the areas close to sows than piglets with incandescent heat lamps (IHL).ICFH helped to reduce the piglet crushing rate.Farrowing houses with ICFH can save 40.6% of the electricity usage compared to IHL.Abstract. Current Chinese heating systems (primarily incandescent heat lamps, IHL) for piglets are energy-consuming, fragile, and short-lived. To overcome these disadvantages, the objectives of this study were to (1) develop an intelligent carbon fiber heater (ICFH) and (2) conduct field experiments to evaluate the performance of the developed heater. The ICFH mainly consisted of an intelligent control unit, a carbon fiber tube, and a heater cover. Three treatments, i.e., ICFH, ICFH with light (ICFHL), and IHL, were respectively assigned to three farrowing pig houses. Pig behaviors, production performance, and electricity usage were recorded in two complete farrowing batches. The results showed that the sows in the ICFH and ICFHL treatments exposed their udders toward the heating area more often than their backs (p < 0.01). Piglets at 1 to 3 days of age in the ICFH and ICFHL treatments increased their time in the heating area by >4.3% (p < 0.01). The proportion of piglets within 0.08 m of the sows was highest for the IHL treatment during 1 to 3 days of age (p < 0.01) but similar among the treatments after day 3 (p = 0.45). The piglet crushing rate in the ICFH and ICFHL treatments was reduced by >2.2% (p < 0.01), while daily weight gain was not significantly different among the treatments (p = 0.16). Using ICFH and ICFHL can reduce electricity usage by 40.6%. It is concluded that the newly developed heater is beneficial for pig thermal comfort, production, and energy savings. Keywords: Automatic sensor technology, Carbon fiber heater, Piglet crushing, PLF.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80286384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling Soil-Metal Sliding Resistance","authors":"D. Robbins, Clarence E. Johnson, R. Schafer, T. Way","doi":"10.13031/TRANS.13978","DOIUrl":"https://doi.org/10.13031/TRANS.13978","url":null,"abstract":"HighlightsA model was developed to express soil-metal sliding resistance in terms of normal stress and sliding path length.Soil-metal sliding resistance data, different from those used to develop the model, were acceptably simulated.The model is expected to be useful in the design and development of soil-engaging equipment.Abstract. Most previous soil-material sliding resistance studies have focused on the measurement and formulation of only qualitative relationships between sliding resistance and the material type, applied normal stress, sliding path length, and/or soil-properties. Few studies have attempted to formulate quantitative mathematical relationships between soil-material sliding resistance and these factors, or to mathematically express the relative contributions of the frictional and adhesive components to the total sliding resistance. In this study, a mathematical model was developed to express the components of soil-metal sliding resistance for a clay soil as functions of applied normal stress and sliding path length. The model is restricted to soil containing enough moisture to exhibit cohesive strength, but not so much moisture to exhibit gross plastic behavior. Soil-metal sliding resistance data, different from those used to develop the model, were acceptably simulated, as the mean square error between the simulated sliding resistance and the measured sliding resistance ranged from 0.653 to 2.44. Keywords: Adhesion, Friction, Normal stress, Sliding path length, Sliding resistance.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76400637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Maneuverability of Wheeled Poly-Articulated Agricultural Vehicles: Modeling and Field Testing","authors":"A. Yatskul, J. Lemière, F. Cointault","doi":"10.13031/TRANS.14262","DOIUrl":"https://doi.org/10.13031/TRANS.14262","url":null,"abstract":"HighlightsModeling provides the relationships between path, kinematics, geometry, and towed implements.Linear interpolation allows trajectories to be compared if data recording is random.Correction coefficients can be a solution to compensate for soil resistance.Abstract. Automatic guidance systems and autonomous vehicles require tested methods of path generation to ensure successful maneuvers (such as automatic trajectory correction and headland turn management). In this study, an evolution of Zakin’s kinematic modeling, as applied in the automobile industry, is proposed for an agricultural poly-articulated vehicle (representing a tractor or other type of towing vehicle with one or more towed implements attached with an articulated hitch). Geometry, vehicle ground speed, and angular steering velocity are considered in the generation of maneuvering paths. Based on the specifics of real field conditions (slope, plant residue, resistance due to soil compaction, etc.), the initial model was improved by introducing correction coefficients. An experimental setup is proposed using a tractor with two towed implements and a testing method involving point-to-point path comparison. The modeling method has potential for integrating more complex procedures (such as path generation, geolocation, and following) into the design of a maneuvering management system for agricultural machines, which can contribute to the efficiency of field operations. Keywords: Agricultural vehicle, Headland turn automation, Maneuverability, Modeling, Path generation, Path planning, Poly-articulated vehicle.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82400425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reduction of Torsional Vibration in Resonance Phenomena for Tractor Power Take-Off Drivelines Using Torsional Damper","authors":"Dang Ahn, In-Kyung Shin, Jooseon Oh, W. Chung, Hyun-Woo Han, Ji-Tae Kim, Young-Jun Park","doi":"10.13031/TRANS.13971","DOIUrl":"https://doi.org/10.13031/TRANS.13971","url":null,"abstract":"HighlightsRattling of tractor power take-off drivelines can be detrimental to operators.A novel driveline model, which includes a torsional damper, was constructed.The behavior of the model was validated against that of an actual tractor driveline.The validated model was used to determine the optimal torsional damper parameters.These optimal parameters were validated by laboratory tests.Abstract. Rattle noise and high levels of vibration in agricultural tractors lower the productivity of the operators and may cause serious health issues in them. This study examined a method for preventing resonance and reducing the torsional vibration that causes rattling in tractor power take-off (PTO) drivelines in the idle state using a two-stage torsional damper. The PTO driveline was simplified to a 6-DOF model based on the principle of equivalent mass moment of inertia using commercial simulation software. The variations in the angular velocity of the PTO drive shaft in an actual tractor were measured and compared to the simulation results using a single-stage torsional damper to validate the model. Using this validated PTO driveline model, the pre spring of a two-stage torsional damper was investigated to determine its optimal torsional stiffness to minimize torsional vibration. The simulation results showed that the variations in the angular velocity of the PTO drive shaft decreased as the torsional stiffness of the pre spring decreased; accordingly, an appropriate torsional stiffness reduced the variation in the angular velocity delivered to the PTO drive shaft. The optimal torsional stiffness of the pre spring was determined by considering the manufacturing limitations of the torsional damper and the magnitude of the input engine torque. A pre spring with this optimal torsional stiffness was installed on an actual PTO driveline to measure the angular velocity transmissibility, which was the ratio of the variation in the angular velocity of the engine flywheel to the variation in the angular velocity of the PTO drive shaft, and the results were compared with those of the simulation. When the angular velocity of the engine was 850 rpm, the angular velocity transmissibility of the PTO drive shaft was 0.4 in the actual test, similar to the value of 0.29 obtained using the simulation. Thus, the simulation-optimized pre spring was able to avoid the resonance domain, while considerably reducing the torsional vibration that leads to rattling. The results of this study support the safe operation of agricultural tractors and guide the evaluation of torsional damper configurations of different vehicles. Keywords: PTO driveline, Resonance, Simulation model, Torsional damper, Torsional vibration, Tractor rattle.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90088334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}