Development of an artificial neural network model with graphical user interface for predicting contact area of bias-ply tractor tyres on firm surface

Rajesh Yadav, Hifjur Raheman

Journal of Terramechanics, Volume 107, 2023, Pages 1-11, ISSN 0022-4898

https://doi.org/10.1016/j.jterra.2023.01.004. (https://www.sciencedirect.com/science/article/pii/S0022489823000046)

Abstract: An Artificial Neural Network (ANN) model was developed for predicting the contact area and ground pressure of bias-ply tractor tyres. A Graphical User Interface (GUI) using Tkinter was created to deploy the developed ANN model. A total of 538 datasets for the 12.4–28, 13.6–28, 14.9–28 and 16.9–28 tyres by varying load on tyres (600 to 1950 kg) and inflation pressure (69 to 234 kPa) were collected from the experimental trials and divided in a ratio of 70:30 for the training and testing of the ANN model, respectively. Another 50 new datasets of all tyres were used for validation purpose. The nominal width and overall diameter of tyre, normal load, and inflation pressure were considered as input parameters for the developed ANN model and the contact area of the tyre was taken as the output parameter. All the input parameters significantly affected the contact area of the tyre, as evident from the sensitivity analysis. The well-trained ANN model coupled with GUI predicted contact area and ground pressure beneath the tyre on firm surface at any inflation pressure and load with a maximum deviation of 2 % from the actual values measured as compared to 10 % and −9% in case of Komandi model.

Keywords: Artificial Neural Network (ANN); Contact area; Graphical User Interface (GUI); Ground pressure; Tkinter

Improvement of the design of the plow-subsoiler-fertilizer to increase soil fertility

Nikolay Romanyuk, Valery Ednach, Sayakhat Nukeshev, Irina Troyanovskaya, Sergey Voinash, Marat Kalimullin, Viktoriia Sokolova

Journal of Terramechanics, Volume 106, 2023, Pages 89-93, ISSN 0022-4898

https://doi.org/10.1016/j.jterra.2023.01.001.(https://www.sciencedirect.com/science/article/pii/S0022489823000010)

Abstract: The use of intensive technologies for the cultivation of agricultural crops provides for the application of fertilizers in the process of tillage. This reduces the compaction of the soil, increases its fertility and the quality of the crop. The purpose of these studies is to develop a universal working tool that allows you to combine several technological operations in one pass of the unit. The authors have developed an original design of a plow-subsoiler-fertilizer. This combined working body includes a reversible plow and a vibratory subsoiler with fertilizer ducts. This solution allows you to combine the application of fertilizers when plowing the field, loosening the subsoil layer and mixing the soil. As a result of the work, the dependences of the geometric dimensions of the structure on the traction resistance to movement in the soil were obtained. To implement the developed idea into a real design, the main parameters of the plow-subsoiler-fertilizer are determined. Particular attention is paid to the calculation of the spring mechanism that ensures the vibration of the subsoiler. The optimal number and location of belleville springs in the block and shock absorber were selected, at which the subsoiler will perform self-oscillations with a given amplitude.

Keywords: Plow Sole; Vibrating Subsoiler; Combined Working Body; Spring Mechanism Force

Vehicle design for terrain mobility: A modeling technique of powertrain power conversion and realization

Vladimir V. Vantsevich, David J. Gorsich, Dmytro O. Volontsevych, Ievhenii A. Veretennikov, Jesse R. Paldan, Lee Moradi,

Journal of Terramechanics, Volume 106, 2023, Pages 75-88, ISSN 0022-4898,

https://doi.org/10.1016/j.jterra.2023.01.003.(https://www.sciencedirect.com/science/article/pii/S0022489823000034)

Abstract: Vehicle terrain mobility characteristics, provided by the powertrain and running gear, are realized in dynamic interactions between the wheels and terrain. Approaches to modeling and simulation of vehicle-terrain interaction and mobility characteristics as well as engineering approaches to design powertrain sub-systems together pre-determine a vehicle’s technical success or failure before it touches the ground. This article develops a vehicle mobility design technique, applicable to both manned and unmanned platforms, concerned with powertrain power conversion and realization in tire-terrain interactions. The modeling component is based on multi-drive-wheel vehicle longitudinal dynamics combined with terramechanics and powertrain characteristics. The approach advances the conventional dynamic factor by introducing the conjoint effect of the engine, transmission, and driveline system on vehicle traction and acceleration performance in terrain conditions where circumferential wheel forces and tire slippages may differ from each other. The vehicle design component of the proposed technique introduces drivetrain, driveline, and powertrain design factors that assess the influence of the drivetrain and driveline systems on traction, acceleration performance, power conversion, and realization at the wheels. The vehicle-design-for-mobility technique is completed by examining indices of mobility margins and performance. An analysis of several 8x8 armored personal carriers and 4x4 off-road vehicles illustrates the proposed technique.

Keywords: Driveline; Dynamic factor; Mobility performance; Power conversion; Powertrain; Terrain mobility; Tire slippage

Gradeability of ‘Zhu Rong’ Mars rover based on the simulated Martian terrain

Yansong Liu, Yingchun Qi, Dong Pan, Zhen Chen, Baofeng Yuan, Meng Zou

Journal of Terramechanics, Volume 106, 2023, Pages 57-73, ISSN 0022-4898

https://doi.org/10.1016/j.jterra.2023.01.002.(https://www.sciencedirect.com/science/article/pii/S0022489823000022)

Abstract: Due to the long-term weathering and erosion climate, many craters terrains on the surface of Mars are covered with loose weathered sedimentary debris, and Mars rovers traversing these slope-like terrains with soft soils will easily slip or even sink, and may affect the survey missions. Therefore, it is important to study the climbing ability of Mars rovers for Mars exploration missions. This work testes the climbing capability of 'Zhurong' Mars rover based on active–passive suspensions under the simulated Martian terrain and soil parameters were adequately measured. The maximum climbing distance (MCD), slip rate, power, current, energy, and efficiency are analyzed to explore the climbing abilities under different climbing methods, soil states and dynamic parameters (speeds, angular velocity) settings. The test results show that the peristaltic mode is able to continue climbing after a direct climb failure, and the MCD per period is influenced by angular velocity. The power and current data can effectively reflect the difficulty of the rover climbing. Under the same dynamic parameters, the greater the slip rate of the rover, the larger the output power and current. In addition, the speed should be minimized to prolong the climbing distance, no matter it is direct or peristaltic climbing.

Keywords: Mars rover; Climbing mode; Gradeability; Simulated Martian soil

A novel evaluation method for rolling energy losses of tacked vehicle road wheels using experimental modal analysis

Chengwei Zhu, Ye Zhuang, Weiguang Fan, Zhenxin Long, Shuyu Zhang

Journal of Terramechanics, Volume 106, 2023, Pages 47-56, ISSN 0022-4898

https://doi.org/10.1016/j.jterra.2022.12.003.(https://www.sciencedirect.com/science/article/pii/S0022489822000878)

Abstract: A novel evaluation method for rolling energy losses of road wheels of tracked vehicle is proposed, in which damping of road wheel surface is identified based on single vibration excitation and single point picking up frequency response function using a simplified modal experiment with an acceleration sensor. Three road wheels of tracked vehicle with different tread rubber are utilized as specimens during the modal experiments. The half power bandwidth method is employed to identify the viscous damping parameters. The damping parameters of road wheels are ranked by their values, and then these values of every road wheels are compared with their corresponding rolling energy losses to validate their correlative relationship. Moreover, the nonlinear deformation and stiffness of road wheels are investigated about their correlation with the rolling energy losses through model development and experimental validation. The results prove that the damping ratios of road wheels are correlated well with the rolling energy losses for all the three road wheels. The proposed evaluation method could effectively evaluate the rolling energy losses of road wheels, which suggests a simplified and economical alternative over the conventional rolling energy losses experimental method of road wheels.

Keywords: Road wheels; Energy losses; Normal stiffness; Experimental modal analysis

Numerical analysis of steady-state mechanical characteristics of the flexible spoke non-pneumatic tire under multiple working conditions

Laiyun Ku, Hongxun Fu, Kai Chen, Jinyan Zhang, Senyu Bi, Lei Zhou

Journal of Terramechanics, Volume 106, 2023, Pages 35-45, ISSN 0022-4898

https://doi.org/10.1016/j.jterra.2022.12.002.(https://www.sciencedirect.com/science/article/pii/S0022489822000866)

Abstract: Since the research on the steady-state mechanical characteristics of the non-pneumatic tire is not perfect at present, in order to comprehensively explore the steady-state mechanical characteristics of a new flexible spoke non-pneumatic tire (FSNPT), the steady-state mechanical simulations under multiple working conditions are carried out. The three-dimensional model and numerical analysis model of the new FSNPT are established, the reliability and accuracy of the simulation model are validated by the bench test. Combined with the tire steady-state rolling theory, simulation tests of steady-state mechanical characteristics of the FSNPT under pure longitudinal slip, pure lateral slip, pure camber and compound working conditions are completed. The steady-state mechanical characteristic curves of the FSNPT under pure and compound working conditions are obtained, the steady-state mechanical characteristic laws are analyzed. The results show that: Under the pure working condition, the tire force or torque has a certain trend with the change of the tire motion state under the same load, with the increase of the load, the longitudinal stiffness, lateral stiffness, aligning stiffness and camber stiffness of the non-pneumatic tire and their corresponding peak values all tend to increase. Under the compound working condition, the influence of the camber on lateral force and aligning moment is directional, that is, it will promote or inhibit the generation of lateral force and aligning moment, but has little influence on the longitudinal force. At the same time, the longitudinal force and lateral force under the compound working condition are mutually restricted; compared with the pure working condition, the generation of the aligning torque under the compound working condition is greatly influenced by the camber and longitudinal slip, and the trend with the lateral slip angle changes significantly. This study provides a theoretical guidance for structural design and performance optimization of the FSNPT.

Keywords: Non-pneumatic tire; Flexible spoke structure; Multiple working conditions; Steady-state mechanics; Numerical analysis

Analyzing mobility trends of tracked vehicles on fine-grained soils in a progressive slip condition using full-scale test data presented in DROVE 3.0

Arman Borazjani, Isaac L. Howard, Zach Griffing, Ashley S. Carey, Farshid Vahedifard, George L. Mason, Jody D. Priddy

Journal of Terramechanics, Volume 106, 2023, Pages 21-34, ISSN 0022-4898

https://doi.org/10.1016/j.jterra.2022.12.001.+(https://www.sciencedirect.com/science/article/pii/S0022489822000854)

Abstract: In 2013, an extensive effort began to create a consolidated off-road vehicle mobility database named DROVE (Database Records for Off-road Vehicle Environments). DROVE consists of over 8,500 experimental test records measured over several decades for wheeled and tracked vehicles over various terrains. This paper introduces the third release of DROVE, which adds results from 193 tests primarily consisting of data for tracked vehicles on fine-grained soils in a progressive slip condition. Performance parameters considered in DROVE 3.0 include drawbar pull, torque, sinkage, and traction. These parameters were compared to mobility numerics, such as soil-track mobility number, contact pressure to cone index ratio, and mean maximum pressure. These parameters were used to develop mobility trends in this paper. DROVE is intended to be a resource for the mobility community applicable to many situations, including evaluating and advancing numerical simulations, improving closed-form algorithms, and understanding vehicular trends that can be used for development or purchase specifications.

Keywords: DROVE; Off-Road Mobility; Database; Wheeled Vehicle; Tracked Vehicle; Fine-Grained Soil; Drawbar Pull; Torque; Sinkage

Development of a mathematical model for determining the draft force of ard plow in silt clay soil

Thomas Gebre, Zewdu Abdi, Amana Wako, Teshome Yitbarek

Journal of Terramechanics, Volume 106, 2023, Pages 13-19, ISSN 0022-4898

https://doi.org/10.1016/j.jterra.2022.11.004.(https://www.sciencedirect.com/science/article/pii/S0022489822000763)

Abstract: Due to Ethiopia's rising population, the prediction of a draft force has several crucial in improving tillage performance in smallholder farmland. It helps in proper usage of animal draught; minimizes operator tragedy and full input data for the ard plow designer. This study aimed to develop an effective mathematical model by selecting appropriate soil properties, tool geometries, and tillage operating conditions for estimating the draft force of the ard plow. A mathematical equation was established using dimensional analysis related to PI-Buckingham-pi theorem. The model was verified and validated using the IBM SPSS statistical software. The correlation between draft force between the measured and predicted value of R2 was 0.877. The developed model was effective in predicting the draft force success for ard plow as much as 87.70%. No significant difference existed between the measured and predicted values at a 0.05 significance level. The scoring standard of the measured draft and the anticipated draft force is normally distributed with a level of confidence of 99%. Investigation consequence showed a developed mathematical formula for estimating the draft force of ard plow in silt clay soil is effective.

Keywords: Dimensional analysis; Tool geometry; Draft force; Mathematical Model

Off-road terrain classification

Lafras Fritz, Herman A. Hamersma, Theunis R. Botha

Journal of Terramechanics, Volume 106, 2023, Pages 1-11, ISSN 0022-4898

https://doi.org/10.1016/j.jterra.2022.11.003.(https://www.sciencedirect.com/science/article/pii/S0022489822000751)

Abstract: Road traffic accidents place a burden on the global economy. This impact is reduced by the development of safer vehicles. Advanced Driver Assist Systems (ADAS) aim to reduce the frequency and severity of accidents. ADASs are designed to operate in well-defined environments, such as first world urban areas. However, 93% of fatal accidents occur in developing countries; areas often without properly maintained roads. ADAS regularly fail to perform as intended in these challenging environments. Terrain classification may improve the performance of ADAS. A lot of research has been conducted on on-road terrain classification, but few studies focus on off-road terrain classification. This study classifies several off-road terrains, based on road roughness using the ISO8608:2016 standard, using a convolutional neural network (CNN). A database of images over different terrains with known road roughness was created using forward and downward facing cameras. Two different classification models were built: one is brand new and the other made use of transfer learning on pretrained model. Terrain data was captured on several on-road and off-road tracks. Results indicate that off-road terrain classification with cameras can be done with high accuracy before a vehicle drives over a specific part of a road.

Keywords: Off-road terrain classification; Road profiles; Off-road vehicle dynamics; Convolutional neural networks; Supervised learning; Image data