Pub Date : 2024-11-15DOI: 10.1016/j.jterra.2024.101028
Anthony T. Fragoso
Autonomous vehicles can experience extreme changes in performance when operating over winter surfaces, and require accurate classification to transit them safely. In this work we consider acoustic classification of winter terrain, and demonstrate that a simple and efficient frequency-space analysis exposed to a small convolutional neural network, rather than recurrent architectures or temporally-varying spectrogram inputs, is sufficient to provide near-perfect classification of deep snow, hardpacked surfaces and ice. Using a dual-microphone configuration, we also show that acoustic classification performance is due to a combination of vehicle noises and vehicle-terrain interaction noises, and that engine sounds can serve as a particularly powerful classification cue for offroad environments.
{"title":"Acoustic winter terrain classification for offroad autonomous vehicles","authors":"Anthony T. Fragoso","doi":"10.1016/j.jterra.2024.101028","DOIUrl":"10.1016/j.jterra.2024.101028","url":null,"abstract":"<div><div>Autonomous vehicles can experience extreme changes in performance when operating over winter surfaces, and require accurate classification to transit them safely. In this work we consider acoustic classification of winter terrain, and demonstrate that a simple and efficient frequency-space analysis exposed to a small convolutional neural network, rather than recurrent architectures or temporally-varying spectrogram inputs, is sufficient to provide near-perfect classification of deep snow, hardpacked surfaces and ice. Using a dual-microphone configuration, we also show that acoustic classification performance is due to a combination of vehicle noises and vehicle-terrain interaction noises, and that engine sounds can serve as a particularly powerful classification cue for offroad environments.</div></div>","PeriodicalId":50023,"journal":{"name":"Journal of Terramechanics","volume":"117 ","pages":"Article 101028"},"PeriodicalIF":2.4,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142650960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-14DOI: 10.1016/j.jterra.2024.101027
Andries J. Peenze, P. Schalk Els
This paper investigates improvements that can be made to predictive control methods for off-road vehicles by adding of realistic steering preview. The objective of this study is to improve the performance and efficacy of predictive controllers by accounting for significant time delays in active and semi-active systems on vehicles. Traditional zero-order and first-order hold methods for steer preview are compared to a more realistic steer preview method. Semi-active suspension, rear wheel steering, and individual brake actuation are used as the actuators on this off-road vehicle. The results show that the addition of a realistic steering preview improves the handling performance of the vehicle in a severe double lane change manoeuvre on rough roads. Up to 10% reduction in roll angle can be achieved with semi-active suspension control. A 34% reduction in side-slip angle is possible with rear wheel steering control and a 15% reduction in side-slip angle is achieved with differential braking control. The controllers can pre-empt and consider the effect of the actuator time delays, and the preview states from the predictive controller are more representative over the prediction horizon. The findings suggest that the addition of a realistic steering preview can improve the performance of predictive controllers on vehicles. Further investigation of other disturbances and their preview effects on the system should be conducted to find further improvements for predictive control strategies on vehicles.
{"title":"Investigation of steer preview methods to improve predictive control methods on off-road vehicles with realistic actuator delays","authors":"Andries J. Peenze, P. Schalk Els","doi":"10.1016/j.jterra.2024.101027","DOIUrl":"10.1016/j.jterra.2024.101027","url":null,"abstract":"<div><div>This paper investigates improvements that can be made to predictive control methods for off-road vehicles by adding of realistic steering preview. The objective of this study is to improve the performance and efficacy of predictive controllers by accounting for significant time delays in active and semi-active systems on vehicles. Traditional zero-order and first-order hold methods for steer preview are compared to a more realistic steer preview method. Semi-active suspension, rear wheel steering, and individual brake actuation are used as the actuators on this off-road vehicle. The results show that the addition of a realistic steering preview improves the handling performance of the vehicle in a severe double lane change manoeuvre on rough roads. Up to 10% reduction in roll angle can be achieved with semi-active suspension control. A 34% reduction in side-slip angle is possible with rear wheel steering control and a 15% reduction in side-slip angle is achieved with differential braking control. The controllers can pre-empt and consider the effect of the actuator time delays, and the preview states from the predictive controller are more representative over the prediction horizon. The findings suggest that the addition of a realistic steering preview can improve the performance of predictive controllers on vehicles. Further investigation of other disturbances and their preview effects on the system should be conducted to find further improvements for predictive control strategies on vehicles.</div></div>","PeriodicalId":50023,"journal":{"name":"Journal of Terramechanics","volume":"117 ","pages":"Article 101027"},"PeriodicalIF":2.4,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142650957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-08DOI: 10.1016/j.jterra.2024.101030
Dávid Körmöczi , Péter Kiss
Accurate modeling or simulation of the vehicle-terrain interaction is critical for effective off-road vehicle navigation. While several high-accuracy methods exist (for example FEM simulation) they typically require computational capacity that exceeds what can be installed in a vehicle. Therefore, they are not applicable for real-time off-road vehicle navigation purposes, where computer hardware capacity is limited by the need for onboard installation. To address this challenge, simplified and less detailed models must be developed for real-time applications. This paper compares three different two-dimensional static terrain-vehicle models, considering accuracy and computational capacity requirements. Results of the comparison provide insights into the suitability of each model for real-time navigation of off-road vehicles.
{"title":"Comparison of selected tire-terrain interaction models from the aspect of accuracy and computational intensity","authors":"Dávid Körmöczi , Péter Kiss","doi":"10.1016/j.jterra.2024.101030","DOIUrl":"10.1016/j.jterra.2024.101030","url":null,"abstract":"<div><div>Accurate modeling or simulation of the vehicle-terrain interaction is critical for effective off-road vehicle navigation. While several high-accuracy methods exist (for example FEM simulation) they typically require computational capacity that exceeds what can be installed in a vehicle. Therefore, they are not applicable for real-time off-road vehicle navigation purposes, where computer hardware capacity is limited by the need for onboard installation. To address this challenge, simplified and less detailed models must be developed for real-time applications. This paper compares three different two-dimensional static terrain-vehicle models, considering accuracy and computational capacity requirements. Results of the comparison provide insights into the suitability of each model for real-time navigation of off-road vehicles.</div></div>","PeriodicalId":50023,"journal":{"name":"Journal of Terramechanics","volume":"117 ","pages":"Article 101030"},"PeriodicalIF":2.4,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142650959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-05DOI: 10.1016/j.jterra.2024.101029
Mohamed A.A. Abdeldayem , Mehari Z. Tekeste
The discrete element method (DEM) has become a valuable computational technique for simulating soil dynamic loading during bulldozer cutting processes. It allows for the virtual design of Ground Engaging Tools (GETs) and predicting energy expenditure during earthmoving operations. Few studies exist for modeling dynamic soil-cutting processes of soils exhibiting elasto-plastic behavior with stress-history-dependent cohesive soil behavior. The study aimed to calibrate an elasto-plastic DEM soil model, with cohesion, for a cohesive-frictional artificial soil and predict soil reaction forces from soil-to-blade interaction. Plackett-Burman screening design of experiment (DOE) and inverse profiling techniques were applied to calibrate the elasto-plastic DEM soil model, with cohesion, predicting soil compaction energy with a percent relative error (PRE) of 3 % and maximum normal stress (PRE of 1 %) using cohesive-frictional artificial soil in a uniaxial confined compression test. Validation of the calibrated DEM soil model resulted in good prediction of soil reaction forces versus blade displacement for a narrow planar blade, a wide planer blade, and a geometrically scaled curved bulldozer blade, with RMSE values of 2.04 N, 14.89 N, and 7.42 N, respectively. The findings showed that elasto-plastic soil behavior with stress-dependent cohesion can be modeled using DEM for simulating the cutting and moving of earthen materials, offering valuable insights for optimizing GET design and development of digital twins of earthmoving operations.
离散元素法（DEM）已成为模拟推土机切割过程中土壤动态载荷的重要计算技术。它可以虚拟设计地面掘进工具 (GET)，并预测推土作业过程中的能量消耗。针对具有弹塑性行为和应力历史依赖性粘性土壤行为的土壤动态切削过程建模的研究很少。本研究旨在校准具有内聚力的弹塑性 DEM 土壤模型，用于内聚摩擦人造土壤，并预测土壤与刀片相互作用产生的土壤反作用力。应用 Plackett-Burman 筛选实验设计（DOE）和反剖面技术校准了具有内聚力的弹塑性 DEM 土壤模型，在单轴约束压缩试验中使用内聚摩擦人造土壤预测土壤压实能，相对误差百分比（PRE）为 3%，最大法向应力（PRE 为 1%）为 1%。对校准的 DEM 土壤模型进行验证后，可以很好地预测窄平面叶片、宽平面叶片和几何比例弯曲推土机叶片的土壤反力与叶片位移的关系，RMSE 值分别为 2.04 N、14.89 N 和 7.42 N。研究结果表明，可以使用 DEM 模拟土质材料的切割和移动，对具有应力相关内聚力的弹塑性土壤行为进行建模，从而为优化 GET 设计和开发土方工程数字孪生模型提供宝贵的见解。
{"title":"Simulation of cohesive-frictional artificial soil-to-blade interactions using an elasto-plastic discrete element model with stress-dependent cohesion","authors":"Mohamed A.A. Abdeldayem , Mehari Z. Tekeste","doi":"10.1016/j.jterra.2024.101029","DOIUrl":"10.1016/j.jterra.2024.101029","url":null,"abstract":"<div><div>The discrete element method (DEM) has become a valuable computational technique for simulating soil dynamic loading during bulldozer cutting processes. It allows for the virtual design of Ground Engaging Tools (GETs) and predicting energy expenditure during earthmoving operations. Few studies exist for modeling dynamic soil-cutting processes of soils exhibiting elasto-plastic behavior with stress-history-dependent cohesive soil behavior. The study aimed to calibrate an elasto-plastic DEM soil model, with cohesion, for a cohesive-frictional artificial soil and predict soil reaction forces from soil-to-blade interaction. Plackett-Burman screening design of experiment (DOE) and inverse profiling techniques were applied to calibrate the elasto-plastic DEM soil model, with cohesion, predicting soil compaction energy with a percent relative error (PRE) of 3 % and maximum normal stress (PRE of 1 %) using cohesive-frictional artificial soil in a uniaxial confined compression test. Validation of the calibrated DEM soil model resulted in good prediction of soil reaction forces versus blade displacement for a narrow planar blade, a wide planer blade, and a geometrically scaled curved bulldozer blade, with RMSE values of 2.04 N, 14.89 N, and 7.42 N, respectively. The findings showed that elasto-plastic soil behavior with stress-dependent cohesion can be modeled using DEM for simulating the cutting and moving of earthen materials, offering valuable insights for optimizing GET design and development of digital twins of earthmoving operations.</div></div>","PeriodicalId":50023,"journal":{"name":"Journal of Terramechanics","volume":"117 ","pages":"Article 101029"},"PeriodicalIF":2.4,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-02DOI: 10.1016/j.jterra.2024.101023
David Gorsich , Vladimir Vantsevich , Jesse Paldan , Lee Moradi
For many decades, different approaches, fundamentals, and expressions have been developed in various countries for military vehicle modelling and simulation (M&S) as a core component of ground vehicle design for mobility. The political division of the world into the West and East that existed before the Soviet Union breakdown in 1991 had not facilitated collaboration between researchers and engineers of both sides, and, thus, they created and practiced their own approaches. The war in Ukraine urgently prompted analysis of the origins and essence of the Western and Eastern technical paradigms, which being conceptually different to ground vehicle mobility, had predetermined the development of vehicle M&S methods and techniques in their parts of the world, specifically for studying dynamic interactions of vehicles with severely uncertain terrains, which impact vehicle behavior and performance, and, thus, may either facilitate mission accomplishment or lead to its failure. Furthermore, this analysis of the technical paradigms aims to further advance M&S fundamentals for next generation combat vehicles as described in the U.S. Army’s 2019 Modernization Strategy. Part I of this article considers the Eastern approach and the Western approach is presented in Part II.
{"title":"Modelling and simulation fundamentals in design for ground vehicle mobility Part II: Western approach","authors":"David Gorsich , Vladimir Vantsevich , Jesse Paldan , Lee Moradi","doi":"10.1016/j.jterra.2024.101023","DOIUrl":"10.1016/j.jterra.2024.101023","url":null,"abstract":"<div><div>For many decades, different approaches, fundamentals, and expressions have been developed in various countries for military vehicle modelling and simulation (M&S) as a core component of ground vehicle design for mobility. The political division of the world into the West and East that existed before the Soviet Union breakdown in 1991 had not facilitated collaboration between researchers and engineers of both sides, and, thus, they created and practiced their own approaches. The war in Ukraine urgently prompted analysis of the origins and essence of the Western and Eastern technical paradigms, which being conceptually different to ground vehicle mobility, had predetermined the development of vehicle M&S methods and techniques in their parts of the world, specifically for studying dynamic interactions of vehicles with severely uncertain terrains, which impact vehicle behavior and performance, and, thus, may either facilitate mission accomplishment or lead to its failure. Furthermore, this analysis of the technical paradigms aims to further advance M&S fundamentals for next generation combat vehicles as described in the U.S. Army’s 2019 Modernization Strategy. Part I of this article considers the Eastern approach and the Western approach is presented in Part II.</div></div>","PeriodicalId":50023,"journal":{"name":"Journal of Terramechanics","volume":"117 ","pages":"Article 101023"},"PeriodicalIF":2.4,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-26DOI: 10.1016/j.jterra.2024.101024
Varsha S. Swamy , Alba Yerro , Corina Sandu , Rashna Pandit , David Gorsich , Katherine Sebeck
Modeling and performance prediction of tires on wet, plastic, cohesive soils is challenging. In wet soils, the undrained shear strength reduces as water content increases. This work aims to model highly deformable saturated clay (plastic state) to predict the short-term effect on the soil due to a single pneumatic tire pass. The external loads on the soil (total stresses) can be carried by the soil skeleton (effective stress) and/or water (pore water pressure). Fundamentally, effective stresses determine soil failure. Hence, material models can be defined using two frameworks: total and effective stress. In total stress analysis, commonly found in literature, soil and water are modeled as one medium to address rapid loading. In effective stress analysis, pore pressure evolution can be tracked through hydromechanical formulations with different drainage conditions (dry and fully saturated soils). Further, different numerical techniques (FEM, ALE, and SPH) are compared. The effective stress model captures an accumulation of excess pore water pressure after one tire pass resulting from soil non-linear behavior, which may potentially affect the tire performance of later passes. In addition, the FEM model fails at higher normal loads and slip ratios due to excessive deformation; ALE and SPH give more stable solutions for large deformations.1
{"title":"Numerical analysis of tire mobility on deformable plastic clay in saturated conditions using total and effective stress frameworks","authors":"Varsha S. Swamy , Alba Yerro , Corina Sandu , Rashna Pandit , David Gorsich , Katherine Sebeck","doi":"10.1016/j.jterra.2024.101024","DOIUrl":"10.1016/j.jterra.2024.101024","url":null,"abstract":"<div><div>Modeling and performance prediction of tires on wet, plastic, cohesive soils is challenging. In wet soils, the undrained shear strength reduces as water content increases. This work aims to model highly deformable saturated clay (plastic state) to predict the short-term effect on the soil due to a single pneumatic tire pass. The external loads on the soil (total stresses) can be carried by the soil skeleton (effective stress) and/or water (pore water pressure). Fundamentally, effective stresses determine soil failure. Hence, material models can be defined using two frameworks: total and effective stress. In total stress analysis, commonly found in literature, soil and water are modeled as one medium to address rapid loading. In effective stress analysis, pore pressure evolution can be tracked through hydromechanical formulations with different drainage conditions (dry and fully saturated soils). Further, different numerical techniques (FEM, ALE, and SPH) are compared. The effective stress model captures an accumulation of excess pore water pressure after one tire pass resulting from soil non-linear behavior, which may potentially affect the tire performance of later passes. In addition, the FEM model fails at higher normal loads and slip ratios due to excessive deformation; ALE and SPH give more stable solutions for large deformations.<span><span><sup>1</sup></span></span></div></div>","PeriodicalId":50023,"journal":{"name":"Journal of Terramechanics","volume":"117 ","pages":"Article 101024"},"PeriodicalIF":2.4,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Japan has many active volcanoes, and a large eruption can cause ash fall over a wide area. The accumulation of volcanic ash on paved roads affects the driving of vehicles. Therefore, we collected data by driving over volcanic ash accumulated on paved surface with a vehicle equipped with devices that can measure the force applied to the running tires. Vehicle driving tests were conducted at constant speed, rapid acceleration, and rapid deceleration. Data were collected on flat straight roads as well as on roads with grades and curves. In addition to longitudinal, lateral, and vertical tire forces, camber angle, rotation speed, and ground speed were measured. This paper discusses the effects of volcanic ash covering paved roads on driving by processing the tire data obtained. The relationship between the sideslip angle and side force can be obtained by processing turning driving data, and these effects were modeled using a neural network and Gaussian process that can consider multiple variables such as tire sideslip angle, camber angle, and vertical force.
{"title":"Analysis of tire characteristics driving on asphalt paved roads covered with volcanic ash","authors":"Junya Yamakawa , Ryosuke Eto , Yasuhiro Ichikado , Mitsuhiro Yoshimoto , Tatsuji Nishizawa , Tomohiro Kubo , Hiroyuki Yamada","doi":"10.1016/j.jterra.2024.101025","DOIUrl":"10.1016/j.jterra.2024.101025","url":null,"abstract":"<div><div>Japan has many active volcanoes, and a large eruption can cause ash fall over a wide area. The accumulation of volcanic ash on paved roads affects the driving of vehicles. Therefore, we collected data by driving over volcanic ash accumulated on paved surface with a vehicle equipped with devices that can measure the force applied to the running tires. Vehicle driving tests were conducted at constant speed, rapid acceleration, and rapid deceleration. Data were collected on flat straight roads as well as on roads with grades and curves. In addition to longitudinal, lateral, and vertical tire forces, camber angle, rotation speed, and ground speed were measured. This paper discusses the effects of volcanic ash covering paved roads on driving by processing the tire data obtained. The relationship between the sideslip angle and side force can be obtained by processing turning driving data, and these effects were modeled using a neural network and Gaussian process that can consider multiple variables such as tire sideslip angle, camber angle, and vertical force.</div></div>","PeriodicalId":50023,"journal":{"name":"Journal of Terramechanics","volume":"117 ","pages":"Article 101025"},"PeriodicalIF":2.4,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-19DOI: 10.1016/j.jterra.2024.101020
Vladimir Vantsevich , David Gorsich
For many decades, different approaches, fundamentals, and expressions have been developed in various countries for military vehicle modelling and simulation (M&S) as a core component of ground vehicle design for mobility. The political division of the world into the West and East that existed before the Soviet Union breakdown in 1991 had not facilitated collaboration between researchers and engineers of both sides, and, thus, they created and practiced their own approaches. The war in Ukraine urgently prompted analysis of the origins and essence of the Western and Eastern technical paradigms, which being conceptually different to ground vehicle mobility, had predetermined the development of vehicle M&S methods and techniques in their parts of the world, specifically for studying dynamic interactions of vehicles with severely uncertain terrains, which impact vehicle behavior and performance, and, thus, may either facilitate mission accomplishment or lead to its failure. Furthermore, this analysis of the technical paradigms aims to further advance M&S fundamentals for next generation combat vehicles as described in the U.S. Army’s 2019 Modernization Strategy. Part I of this article considers the Eastern approach and the Western approach is presented in Part II.
{"title":"Modelling and simulation fundamentals in design for ground vehicle mobility part I: Eastern approach","authors":"Vladimir Vantsevich , David Gorsich","doi":"10.1016/j.jterra.2024.101020","DOIUrl":"10.1016/j.jterra.2024.101020","url":null,"abstract":"<div><div>For many decades, different approaches, fundamentals, and expressions have been developed in various countries for military vehicle modelling and simulation (M&S) as a core component of ground vehicle design for mobility. The political division of the world into the West and East that existed before the Soviet Union breakdown in 1991 had not facilitated collaboration between researchers and engineers of both sides, and, thus, they created and practiced their own approaches. The war in Ukraine urgently prompted analysis of the origins and essence of the Western and Eastern technical paradigms, which being conceptually different to ground vehicle mobility, had predetermined the development of vehicle M&S methods and techniques in their parts of the world, specifically for studying dynamic interactions of vehicles with severely uncertain terrains, which impact vehicle behavior and performance, and, thus, may either facilitate mission accomplishment or lead to its failure. Furthermore, this analysis of the technical paradigms aims to further advance M&S fundamentals for next generation combat vehicles as described in the U.S. Army’s 2019 Modernization Strategy. Part I of this article considers the Eastern approach and the Western approach is presented in Part II.</div></div>","PeriodicalId":50023,"journal":{"name":"Journal of Terramechanics","volume":"117 ","pages":"Article 101020"},"PeriodicalIF":2.4,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-09DOI: 10.1016/j.jterra.2024.101018
Leonardo Angelucci , François Pinet , Andrea Vertua , Michele Mattetti
A reliable testing procedure is needed to benchmark different vehicle and tyre parameters. Several testing procedures within two main families – transient and steady states – were adopted to evaluate drawbar performance of tractors. The two procedural families were not hitherto compared using a full vehicle. This article aims to fill this gap. The transient and steady-state procedures were tested using a tractor rated of 230 kW sets in different configurations and equipped with sensors for evaluating the tractive parameters. In the transient procedure, the drawbar load was continuously increased to maintain a fixed ground speed. In the steady-state procedure, the drawbar load was gradually increased by reducing the ground speed. The maximum drawbar force generated by the tractor differed little between procedures, but a difference was observed in power delivery efficiency, mostly for the transmission’s influence during transient conditions leading to variable transmission efficiency. The results of the steady-state procedure for different vehicle configurations were more consistent with findings in the literature than those of the transient procedure. The steady-state procedure is better than the other but it requires more land and therefore it is less convenient when drawbar performances must be quickly evaluated for many vehicle and soil configurations.
{"title":"Towards more efficient tractors: Assessing and refining traction test procedures for agricultural tractors","authors":"Leonardo Angelucci , François Pinet , Andrea Vertua , Michele Mattetti","doi":"10.1016/j.jterra.2024.101018","DOIUrl":"10.1016/j.jterra.2024.101018","url":null,"abstract":"<div><div>A reliable testing procedure is needed to benchmark different vehicle and tyre parameters. Several testing procedures within two main families – transient and steady states – were adopted to evaluate drawbar performance of tractors. The two procedural families were not hitherto compared using a full vehicle. This article aims to fill this gap. The transient and steady-state procedures were tested using a tractor rated of 230 kW sets in different configurations and equipped with sensors for evaluating the tractive parameters. In the transient procedure, the drawbar load was continuously increased to maintain a fixed ground speed. In the steady-state procedure, the drawbar load was gradually increased by reducing the ground speed. The maximum drawbar force generated by the tractor differed little between procedures, but a difference was observed in power delivery efficiency, mostly for the transmission’s influence during transient conditions leading to variable transmission efficiency. The results of the steady-state procedure for different vehicle configurations were more consistent with findings in the literature than those of the transient procedure. The steady-state procedure is better than the other but it requires more land and therefore it is less convenient when drawbar performances must be quickly evaluated for many vehicle and soil configurations.</div></div>","PeriodicalId":50023,"journal":{"name":"Journal of Terramechanics","volume":"117 ","pages":"Article 101018"},"PeriodicalIF":2.4,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soil deformation is one of the parameters affecting the performance of off-road vehicles, including traction, mobility, and steering. This study offers an examination of soil deformation resulting from interactions with pneumatic and track wheels. Experiments were conducted using a soil bin with a single-wheel test rig, equipped with both a standard agricultural tire and a customized track wheel. Three distinct levels of vertical loads (2, 3, and 4kN) and forward velocities (1, 2, and 3 km/h) were applied using the wheel tester. The displacement and deformation of the soil layers, visualized as a vertical cross-section along the motion path, were consistently prepared and photographed for all experiments. Image analysis was undertaken with MATLAB software to scale images and extract graphical data. The highest deformation, with a value of 60.86 mm, is associated with the interaction of a pneumatic wheel with a force of 4 kN, while the lowest deformation occurs when the soil interacts with a track wheel with a force of 2 kN, with a value of 25.05 mm. Furthermore, the fitted surfaces obtained using the optimization algorithm showed good convergence with the experimental data, with R2 values of 0.9783 and 0.9516 for the pneumatic tire and tracked tire, respectively. The results demonstrated that the TRR model performs well in accurately predicting soil deformation induced by various types of wheels. A comparison between soil deformations caused by track wheels and pneumatic wheels revealed that track wheels result in less deformation and disturbance, particularly in the upper soil layers. These findings underscore the importance of considering the type of traction device and loading conditions when assessing soil deformation in agricultural environments.
{"title":"Predicting terrain deformation patterns in off-road vehicle-soil interactions using TRR algorithm","authors":"Behzad Golanbari , Aref Mardani , Adel Hosainpour , Hamid Taghavifar","doi":"10.1016/j.jterra.2024.101021","DOIUrl":"10.1016/j.jterra.2024.101021","url":null,"abstract":"<div><div>Soil deformation is one of the parameters affecting the performance of off-road vehicles, including traction, mobility, and steering. This study offers an examination of soil deformation resulting from interactions with pneumatic and track wheels. Experiments were conducted using a soil bin with a single-wheel test rig, equipped with both a standard agricultural tire and a customized track wheel. Three distinct levels of vertical loads (2, 3, and 4kN) and forward velocities (1, 2, and 3 km/h) were applied using the wheel tester. The displacement and deformation of the soil layers, visualized as a vertical cross-section along the motion path, were consistently prepared and photographed for all experiments. Image analysis was undertaken with MATLAB software to scale images and extract graphical data. The highest deformation, with a value of 60.86 mm, is associated with the interaction of a pneumatic wheel with a force of 4 kN, while the lowest deformation occurs when the soil interacts with a track wheel with a force of 2 kN, with a value of 25.05 mm. Furthermore, the fitted surfaces obtained using the optimization algorithm showed good convergence with the experimental data, with R<sup>2</sup> values of 0.9783 and 0.9516 for the pneumatic tire and tracked tire, respectively. The results demonstrated that the TRR model performs well in accurately predicting soil deformation induced by various types of wheels. A comparison between soil deformations caused by track wheels and pneumatic wheels revealed that track wheels result in less deformation and disturbance, particularly in the upper soil layers. These findings underscore the importance of considering the type of traction device and loading conditions when assessing soil deformation in agricultural environments.</div></div>","PeriodicalId":50023,"journal":{"name":"Journal of Terramechanics","volume":"117 ","pages":"Article 101021"},"PeriodicalIF":2.4,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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