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The Tire Pressure Monitoring System (TPMS) has evolved into an essential element of contemporary vehicles, playing a pivotal role in enhancing road safety and the overall driving experience. Traditionally, TPMS systems rely on dedicated hardware components for the collection and transmission of tire pressure data to the vehicle's onboard computer and the data is visible only to the driver. In this research, we have developed a wireless communication system between TPMS and a server, enabling tire pressure data to be accessible not only to the driver but also remotely traceable by others. To build a reliable communication system, we utilized a combination of Orthogonal Frequency Division Multiplexing (OFDM) and Convolutional Code technologies. This system is implemented using Software-Defined Radio (SDR) technology. This communication method employs OFDM to enhance data throughput and integrates Convolutional Code to mitigate errors in received data. Consequently, this approach achieves a maximum throughput of 119.19MBps when utilizing the OFDM system alongside 16QAM modulation. The bit error rate for received data without coding stands at 5.77%, but the application of Convolutional Code with a 1/2 code rate effectively reduces this error rate to 3.85%. This system improves the reliability of TPMS communication with the server while also ensuring a consistently high throughput. It enhances road safety and remote monitoring capabilities.

The paper presents research on measuring and the possibility of prediction of noise levels on the left and right sides of the operator within the cabin of an agricultural tractor when moving across various agrotechnical surfaces, considering movement velocity and tire pressures while employing machine learning techniques. Noise level measurements were conducted on a LANDINI POWERFARM 100 type tractor, and aligned with standards (HRN ISO 5008, HRN ISO 6396 and HRN ISO 5131). The obtained noise values were divided into two data sets (left and right set) and processed using multiple linear regression (mlr) and three machine learning methods (gradient boosting machine (gbm); support vector machine using radial basis function kernel (svmRadial); monotone multi-layer perceptron neural network (monmlp)). The most accurate method, considering surfaces, from the left side data set—(R2 0.515–0.955); (RMSE 0.302–0.704); (MAE 0.225–0.488)—and the right side—(R2 0.555–0.955); (RMSE 0.180–0.969); (MAE 0.139–0.644)—was monmlp predominantly, and to a lesser extent svmRadial. On analyzing the total data sets from the left and right sides regarding surfaces, gbm emerged as the most accurate method. The application of machine learning methods demonstrated data accuracy, yet in future research, measurements on certain surfaces may need to be repeated multiple times potentially to improve accuracy further.

The paper presents research on measuring and the possibility of prediction of noise levels on the left and right sides of the operator within the cabin of an agricultural tractor when moving across various agrotechnical surfaces, considering movement velocity and tire pressures while employing machine learning techniques. Noise level measurements were conducted on a LANDINI POWERFARM 100 type tractor, and aligned with standards (HRN ISO 5008, HRN ISO 6396 and HRN ISO 5131). The obtained noise values were divided into two data sets (left and right set) and processed using multiple linear regression (mlr) and three machine learning methods (gradient boosting machine (gbm); support vector machine using radial basis function kernel (svmRadial); monotone multi-layer perceptron neural network (monmlp)). The most accurate method, considering surfaces, from the left side data set—(R2 0.515–0.955); (RMSE 0.302–0.704); (MAE 0.225–0.488)—and the right side—(R2 0.555–0.955); (RMSE 0.180–0.969); (MAE 0.139–0.644)—was monmlp predominantly, and to a lesser extent svmRadial. On analyzing the total data sets from the left and right sides regarding surfaces, gbm emerged as the most accurate method. The application of machine learning methods demonstrated data accuracy, yet in future research, measurements on certain surfaces may need to be repeated multiple times potentially to improve accuracy further. [ABSTRACT FROM AUTHOR]

One of the promising steps to improve the environment in various industrial sectors is the transfer of specialized technical means to alternative clean energy. Agriculture is not an exception, because the introduction of an electric drive on tractors of small traction classes, which are designed to perform traction, as well as small transport work, is relevant today. Such an implementation is implemented by replacing the internal combustion engine with an electric drive, in connection with this; the task of observing the traction properties of the tractor arises. Therefore, the material of this type aims to increase the traction efficiency of the wheeled lowpower tractor by optimizing its design features. The implementation of the outlined goal occurs due to the use of multi-criteria optimization when conducting a simulated numerical experiment of traction test cycles. When solving the set goal, the method of dynamic tests of the German Agricultural Society DLG-PowerMix is used, this includes 12 traction tests of an agricultural tractor. The result is a justified selection of the distribution of the total weight of the low-power tractor in combination with the tire pressure in conditions of compliance with the maximum average integral values of the speed and efficiency of the tractor, as well as the minimum average integral value of skidding, as those that should be implemented in an electric tractor. The practical significance of the work consists in providing specific values of weight distribution on the axle of the low-power tractor and tire pressure when aggregating with a plow, a cultivator, a rotary cutter and a hay mower, as well as taking into account the operation of a manure spreader and a hay baling. The scientific novelty of the work is the establishment of a relationship between the design parameters of the low-power tractor and the change in traction indicators during traction work, namely between the tractor weight distribution, tire pressure, speed, tractor efficiency and wheel slip. [ABSTRACT FROM AUTHOR]

An experimental investigation was conducted in this study to assess the effect of the front toe angle and tire pressure on the fuel efficiency of light-duty vehicles. According to the investigations, increasing the toe angle results in an increase in rolling resistance, which has an impact on the fuel efficiency of the vehicle. It was observed that due to misalignment of the front toe-in angle (0.00° to 5.06°) and front toe-out angle (0.00° to −5.06°), the car had traveled approximately 7.38 km and 7.63 km less for the same amount of fuel. The rate of increase in fuel consumption was found to be about 74 % and 79.31 %, respectively. Also, it was shown that under steady-state conditions, the rolling resistance varies nonlinearly with tire inflation pressure while the fuel consumption varies nearly linearly. As the tire pressure lowered (under-inflation, 22 psi), it was observed that the vehicle's rolling resistance rose at a rate of nearly 85.10 % and fuel consumption increased at a rate of nearly 40.29 %. In contrast, the rolling resistance and fuel consumption were considerably reduced as the tire pressure increased from 33 psi to 42 psi (over-inflation). Finally, a regression model was proposed using test data. Such a model would be useful to explain the relationship between the related factors and determine the rate of fuel consumption. [ABSTRACT FROM AUTHOR]

Abstract Selection of optimum platoon pattern based on types of trucks inside the platoon, the number of trucks in the platoon, headway distance, interplatoon distance as well as the use of different lateral wander modes for autonomous trucks has been analyzed. The objective of this research is to study the impacts of axle configurations, truck grouping, headway distance and lateral wander options on the performance of truck platoons. Four different headway distances from 2 to 5 m are compared. The first platoon PT-1 only consists of semi trailers, the second platoon PT-2 only consists of rigid body trucks and the third platoon PT-3 consists of equally distributed random traffic mix. Analysis has been conducted using the dload subroutine for projecting zero wander and uniform wander movements for each truck in the platoon on a three layered pavement crossection at vehicle speeds of 90 km/h for a total of 15 years of pavement lifetime consisting of 1.4 million equivalent single axle loads in finite element software ABAQUS. Results show that PT-3 platoon yields the minimum accumulation of damaging strains when compared against other platoon types. A headway distance of 5 m is suggested when using a zero wander mode and 3 m when using a uniform wander mode. In case of zero wander mode, fatigue life of the pavement decreases by 1.2 years and the use of uniform wander mode delays the rutting by 1.6 years, thereby increasing lifetime of the pavement.

Intensive agricultural practices affect soil compaction, and their indirect and direct effects on crop growth and development are an increasingly important focus of scientific research. The objective of this study was to determine the influence of different tillage systems on soil compaction and to observe the influence of tractor tire pressure on penetrometer resistance during sowing. The three-year study was conducted on the heavy pseudogley soil of Brod-Posavina County in the Republic of Croatia. During the research, crops were observed in the following cropping sequence: soybean (Glycine max L.) in the first year, maize (Zea mays L.) in the second year and winter wheat (Triticum aestivum L.) in the third year. The tillage systems as the main study factor were conventional tillage (CT) plowing to a depth of 35 cm, disc tillage (DH) to a depth of 15 cm, loosening (CH) to a depth of 30 cm, and undermining (SS) to a depth of 50 cm. The following pressures were used as a subfactor of this study, namely the pressure of the front and rear tires of the tractor during sowing: p1 (front 1.0 bar/rear 0.8 bar), p2 (front 2.0 bar/rear 1.6 bar), and p3 (front 3.0 bar/rear 2.4 bar). The tillage systems applied resulted in different soil compaction, thus the deepest tillage SS had the lowest resistance and the DH tillage had the highest resistance in all three experimental years. Penetrometer measurements showed the influence of tire pressure p1 on reducing compaction as early as the first year in 2017, while in the last year of research in 2019, tractor tire pressure p3 during sowing contributed to a significant increase in soil compaction. [ABSTRACT FROM AUTHOR]

Problem. In the scientific and methodological recommendations of forensic institutions and in the scientific and technical literature there are currently no universal methods for determining the braking parameters of cargo multi-axle vehicles that have wheels with double tires, which affects the results of drawing up the conclusions of the motor-technical expertise. The lack of universal methods is due to the difficulty of determining the actual braking, especially when the tires of dual wheels interact with the road surface. Goal. The goal is justification of the method of determining the average torsional stiffness of tires of a double vehicle wheel during its interaction with the road surface. Methodology. The approaches adopted in the work to achieve the set goal are based on the theoretical foundations of the deformation of elastic elements, which are located parallel to each other. Results. Equations are determined that allow you to calculate the value of the average torsional stiffness of the tire for wheels that have double, triple or quadruple tires. Originality. The results of the research provide a general idea of the effect of the pressure in the tires of a double wheel on the value of its average torsional stiffness. Practical value. The obtained results can be recommended to expert motor technicians when drawing up a conclusion of an expertise or an expert study. Besides, the results of the study can be used in the educational process during the training of specialists in the field of transport or mechanical engineering.

The changes in tire pressure will cause braking force to significantly vary due to the change in the tire-to-road contact during hard braking. The most important reason of this issue is the changes in road contact because of the changes in the vertical stiffness and slip stiffness of tire, as tire pressure varies. Therefore, in this study, it was aimed to investigate the effects of the tire pressure on anti-lock brake system (ABS) control performance through vertical and slip stiffness of tire. For this, first, the friction coefficient extended to tire pressure was integrated into the braking dynamics equations using the magic tire model. In this way, the effects of tire pressure were analytically revealed on braking performance. Then, taking into account the theoretical results, ABS braking tests were carried out with three different tire pressures: higher (38 psi) and lower (25 psi) tire pressure than the nominal (33 psi) tire pressure. In experimental studies, tests were carried out for braking initial speeds 30 and 60 km/h with the same tire pressures in µ-jump road conditions. In this way, the effects of the tire pressure were experimentally investigated on control performance of ABS under critical road conditions. At 33 psi tire pressure, the highest brake pressure was observed when switching to wet roads. At 25 psi tire pressure, the brake pressure did not build up in time. This showed that low tire pressure causes brake pressure to increase with a delay. On the slippery part, the lock-up limit is closer at 38 psi tire pressure. Therefore, it was seen that the decrease and increase in tire pressure have great effect on control performance of ABS under µ-jump road conditions. [ABSTRACT FROM AUTHOR]

The rolling friction of a road bicycle tire was measured as a function of changing tire pressure. Five different tire pressures, ranging from 40 to 120 psi, were tested in increments of 20 psi. The power input to the pedals and wheel speed were collected using a crank-based power meter and speed sensor. It was found that rolling friction increases with decreasing tire pressure in an inversely proportional relationship.

Protecting the soil, which serves as the basis for crop production, is a major challenge in view of the increasing weight of agricultural machinery. In the context of soil compaction, track depth is an important measure. As part of the ARDopt research project, the suitability of various ultrasonic sensors and photogrammetric methods for measuring the track depth was investigated. In addition, the influence of the parameters tire pressure, driving speed and soil moisture on the track depth was investigated. The continuous measurement of the track depth with commercially available ultrasonic sensors and the calculation of the track depth from digital surface models show a close correlation with the reference measurements. The tire pressure had the strongest influence on the measured track depth. Likewise, as expected, the influence of soil moisture on the track depth could be observed. [ABSTRACT FROM AUTHOR]

The article presents the results of research on the influence of the pressure in car tires on the braking distance. Tires with lower than nominal pressure, higher than nominal pressure and for comparison with nominal pressure were analyzed. The tests were carried out on a bituminous surface typical for most road surfaces in Poland. Six tests were carried out on a dry surface, a wet surface, and a surface covered with snow. The cars were equipped with sets of summer and winter tires. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the study is to find out whether and to extent the change of selected parameters of the system, such as the type of tires, tire pressure and axle load, changes the result of the technical test of the analysed vehicle in the field of measuring braking forces. Design/methodology/approach: Diagnostic tests, tire pressure measurements, axle load measurements, braking force measurements on a roller device were carried out. Findings: The relationships between the pressure in the tires and the braking force measured on the wheel as well as between the braking force and the load acting on the vehicle axle have been demonstrated. Research limitations/implications: Mathematical relationships between tire pressure and vehicle braking force can be derived in the future. Practical implications: In the course of the tests, it was found that the technical tests made it possible to determine the braking forces only while maintaining the nominal ±1×105 Pa tire pressure. Changes to this parameter may influence the measurement results. Moreover, the influence of tire pressure on the change of the measured braking force values was found, which translates into the safety of the vehicle in road traffic. Originality/value: approach to brake system. [ABSTRACT FROM AUTHOR]

In India, the axle loads have increased substantially in the recent decades and a majority of such overloaded vehicles are expected to have increased tire pressure. Increased tire pressures have a significant impact on the performance of the pavement as the load is applied over a concentrated area. Very little data is available related to the magnitude of tire pressures currently observed in India and its impact on the rutting (Nr) and fatigue (Nf) life of bituminous pavements. This study aims at quantifying such information for India. A field survey was conducted at five weighbridges for 100 vehicles to measure the tire pressures and the corresponding axle loads. Considering all the rear axles, it was observed that the mean tire pressure was 833 kPa and about 50% of the vehicles operated with a tire pressure greater than 800 kPa. To illustrate the combined influence of axle load and tire pressure, pavement sections available in IRC: 37-2018 were chosen and evaluated for their rutting and fatigue performance. For instance, for 10% CBR and 50 Million Standard Axles (MSA) traffic, when the tire pressure was increased from 500 kPa to 1200 kPa, it was observed that Nf reduced by 41% and Nr reduced by 5%. The fatigue life of the surface layer is seen to be more sensitive to variation in tire pressure. Moreover, the magnitude of influence exerted by the tire pressure depended on the axle load to a large extent. [ABSTRACT FROM AUTHOR]

The evaluation of road roughness plays a critical role in the life-long maintenance of the highway system. This study proposes a Kalman Filter-based scheme to evaluate the road roughness indirectly from the response of a moving adapted monitoring vehicle. Key feature of the scheme is the use of measurements from dynamic tire pressure of unsprung mass components that directly interact with roads. Combination of ideal gas law and elastic contact model results in a nonlinear relationship between the tire pressure and the contact force, in which the parameters are calibrated by the Extended Kalman Filter. Identification of vehicle's physical parameters adopts the power spectrum method with a known-size bump test. Subsequently, the road roughness is treated as unknowns in the vehicle's state-space equation and solved by the Discrete Kalman Filter with unknown inputs. The estimated road roughness profiles are then used to calculate the International Roughness Index and compared with that provided by the standardized laser profilometer, an outer-systematic comparison. On the other hand, available measurements are split into groups that measurements of tire pressure are used to predict the accelerations of the car body and wheels and compared with these accelerations directly measured from accelerometers, an inner-systemic comparison. Field tests are carried out on a 900 m long standardized road under two scenarios of with and without the bump and four different vehicle running speeds from 20 to 50 km/h. Consistence of comparison from different perspectives proves the reliability of the proposed scheme. In addition, the results unveil that the scenario with a lower running speed can offer a better estimation of road roughness. [ABSTRACT FROM AUTHOR]

Occurrence of top down and bottom up fatigue cracking in asphaltic pavements is common. Conventional pavement analysis methods ignore the existence of cracks in asphaltic layers. However, it seems that the responses of cracked pavement would not be the same as a pavement without crack. This paper describes effects of crack type, position and length, and vehicles tire inflation pressure and axle load on the performance of cracked asphalt pavement. Tensile strain at the bottom of asphaltic layer, the vertical strain on subgrade, maximum deflection on the surface, rut depth and the stress intensity factors of cracked pavement, with top down and bottom up crack have been computed using 3D Finite Elements method in ABAQUS. Moving load of standard single axle with different loads and tire pressures have been used in the analysis. Standard 8.2 ton single axle load at different tire pressures of 552(80), 690(100), 828(120) and 1035(150) kPa(psi) and single axle at different loads of 5, 8.2 and 15 ton, all at the same tire pressure of 690 kPa, have been used. Results show that the pavement responses increase with increasing tire pressure and axle load with higher values and rate of increase with increasing tire pressure and axle load for the cracked pavement compared with the pavement without crack. For the pavement structure investigated in this study, it was found that, in general, top down crack results in higher responses than bottom up crack.

Tire pressure monitoring is essential to driving safety. Indirect tire pressure monitoring system (TPMS) is a cost-effective alternative to direct tire pressure monitoring system. Its performance depends on the algorithm for data pre-processing and analysis which is normally complicated, sensitive to initial calibration with limited working range. In this work, four tests were carried out with Baojun 530 with a different deflated tire in each case. Speed data read through ABS CAN bus was analyzed and traditional frequency based method was employed to identify the deflated tire. To simplify the data pre-processing and improve response speed and working range, a new artificial neural network (ANN) based method was also proposed to identify deflated tire based on speed data point collected through antilock brake system (ABS) sensors in tests. A long short-term memory (LSTM) network was developed to locate the deflated tire with an accuracy of 0.83 after training for individual data points. And performance of this method can be further improved by employing a soft voting mechanism with 3 LSTM networks. In proposed ANN based method, benchmark data from properly inflated tire is not required, which makes it a promising solution for multiple deflated tires cases which is challenging for traditional frequency-based method.

The tire pressure state directly affects the safety and economy of the vehicle. Its monitoring is gradually becoming a necessary function for all types of vehicles. However, the existing sensor-based monitoring method is costly and without any redundancy when the sensor fails, which hinders its wide applications. This article proposed a machine learning-based framework without any additional sensors. First, the rigid tire model is introduced for feature extraction. Then, the manufacturing error in speed gear is calculated and removed by the recursive least square method. Next, the features in time- and frequency-domain of speed signals are extracted. Finally, based on the suitable signals filtered by the decision tree, the normal and pressure-loss judgment are given out by support vector machine and final synthesis. The results show that the proposed framework has 96.18% report accuracy and has the potential for further estimation of the characteristics in tires and roads. [ABSTRACT FROM AUTHOR]

The road damage coefficient β is a significant indicator to estimate the degree of the road damage caused by vehicles. The existing calculation method of β is not convenient for the engineering application. To effectively evaluate the damage degree and facilitate the engineering application, this paper studied the simple and reliable analytical calculation method of β. Firstly, a dynamic model of the vehicle–road system was created. The tire pressure and the tire damping were considered in the model. Moreover, the relationship between the tire vertical stiffness and the tire pressure is approximated as a linear function. Secondly, based on the dynamic model, according to the definition of β , a concise analytical formula of β was derived and verified by numerical simulations. The relative errors of the analytical calculation results are all less than 0.1%. Thirdly, the influences of the tire pressure p , the damping ratio ξ s of the suspension system, and the damping ratio ξ t of the wheel system on β were analyzed. Moreover, based on the analytical formula of β , a mathematical model of the optimal damping matching for the suspension system was established and a case study was also given. The research results show that the larger the tire pressure p , the larger the value of β is. For each p , there is an optimal damping ratio ξ s . If the tire damping is ignored, it will lead to the design error for ξ s . Finally, some important conclusions were drawn. The analytical formula of β and the conclusions can provide valuable references for the analysis of the road damage and the initial design of vehicle suspensions. [ABSTRACT FROM AUTHOR]

In this study, we aimed to determine the reliability of estimating the specific fuel consumption by using ANN instead of long and costly testing approaches. For this purpose, specific fuel consumption was determined at different axle loads, tire pressures and drawbar forces for a 60 HP tractor. In addition, the results were also estimated with the help of Artificial Neural Networks, which is one of the machine learning methods. The tests were carried out on the Tractor Draft Test Track. In the study, three different drive tire inner pressures (160 kPa, 120 kPa and 80 kPa), four different dynamic axle loads (1796 daN, 2076 daN, 2276 daN, 2476 daN) with adding extra loads and four different traction forces (500 daN, 1000 daN, 1500 daN, 2000 daN) were tested for their effects on specific fuel consumption. Specific fuel consumption values varied between 290.7-542.1 g/kWh depending on the draft force in the tests. Despite the 38% increase in the axle load, a 3.5% decrease occurred in the specific fuel consumption values. Specific fuel consumption values increased when tire inner pressure increased. Specific fuel consumption increased by 1.03% when a 100% increase in tire pressure was realized. In ANN, the most successful model was determined by trying different training algorithms, transfer functions and the number of neurons in the hidden layer. In the most successful network model, MAE, RMSE values for the prediction of specific fuel consumption were found to be 0.005331,0.007551 respectively. [ABSTRACT FROM AUTHOR]

The research included a standard study of the age of the which tires are (80%) and (50%) of standard condition and the inflation of the rear tire of the boat are (32) psi and (27) psi and the affect in both of the following properties(draft force, loss power to slippage, fuel consumption, effective field capacity, energy utilization efficiency, volume of soil disturbed, soil penetration resistance, dry bulk density) The experiment was carried out in a global experiment by using the Duncan test with experimental design (RCBD) was used to show the significance of the differences between the average transactions. The result showed a significant effect of the age of the tires in all the studied traits except for the description of the apparent density and showed a significant effect of the pressure factor of the tire bulge in all studied traits except of effective field capacity, volume of soil disturbed, dry bulk density. All the studied traits were significantly affected by the dual interference between the age of tires and pressure of bulge except for the dry bulk density which did not affect significantly.

Three bump sizes, six pressures and five placement angles of bump were used in this paper to conduct enveloping stiffness experiments. The experimental tire displacement-load curves showed that the enveloping stiffness of the tire under the same pressure did not change with changes of the bump size. And the enveloping stiffness of the tire were changed with changes of pressures and placement angles; Models consider pressure and placement angle of bump were established respectively, and established a model consider pressure and placement angle simultaneously by least squares, those models can be used to estimate enveloping stiffness force without experiments. Abaqus finite element software simulations showed that the stress distribution in the tread is H-shaped and the deformation distribution in the tread is oval; By analyzing the force distribution of the ply found that the distribution of force changes with the change of placement angles. The lateral displacement(U1) of the belts increases linearly with increasing angle. The end of cord is prone to failure at 0° and 45°, and the cord near middle of ply is also prone to failure at all angles.

Determining the exact values of the rolling radii of the wheels is extremely important in terms of the functioning of the safety systems of modern vehicles. It is on the basis of the rotational speed of the vehicle wheels that the traction parameters of the vehicle are determined, as well as the warning about the existence of low tire pressure. The precision of determining the turning radius significantly improves the accuracy of calculations of the slip value, driving force, and also plays a key role in determining the linear speed of a motor vehicle. This article presents the method of determining the value of the rolling radius of a tire and tests of changes in its value under the influence of changes in the value of vertical load and tire pressure. Based on the performed measurements, a mathematical model of changes in the value of the effective wheel rolling circumference from the above-mentioned parameters was determined. The results of the regression analysis indicate a very good fit of the developed model to the results of the conducted experimental research. [ABSTRACT FROM AUTHOR]

The value of tire pressure affects a number of important vehicle features. The article pays attention to assessing the impact of the change in the tire pressure on both the rolling resistance and fuel consumption. The measurements were performed with four different values of tire pressure. The impact of the change in the tire pressure on the rolling resistance was measured during the driving tests. In order to measure the rolling resistance during tests, the measurement methodology was devised and a device for measuring the rolling resistance was constructed. The measurement of the impact the tire pressure change on the fuel consumption was performed via vehicle dynamometer. The result showed a linear dependence between the tire pressure and rolling resistance. These results measured points to the importance of keeping the correct value of the tire pressure in relation to the fuel consumption. [ABSTRACT FROM AUTHOR]

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The transmission of mechanical front-wheel drive tractors normally has a front axle lead ratio, which is equal to 1.5…2.5%. Naturally, when ballast masses are added to the tractor or when inflation pressure in the tires is reduced, distortion of the tires is inevitable, which changes the lead of the front wheels. In this paper, we present the impact of tire inflation pressures on the lead front drive wheels and movement resistance force when the tractor travelled with a front drive axle enabled and was engine braking with the fuel supply off. It was found that the variation in front and rear tires inflation pressure combination can significantly change the lead of the front drive wheels. For the tested tractor up to 6.9%. The result is that when the tractor travelled with the front axle enabled and was engine braking, the engine-braking efficiency decreases with increasing lead of the front wheels. Front (slipping) wheels create the opposite-direction torque, which is transferred to the rear wheels through the tractor’s front-rear axle drive system. Additional losses of the engine braking occur in transmission due to power circulation, and the result is that the tractor wheels receive less braking torque from the engine. First published online 8 October 2019

The transmission of mechanical front-wheel drive tractors normally has a front axle lead ratio, which is equal to 1.5...2.5%. Naturally, when ballast masses are added to the tractor or when inflation pressure in the tires is reduced, distortion of the tires is inevitable, which changes the lead of the front wheels. In this paper, we present the impact of tire inflation pressures on the lead front drive wheels and movement resistance force when the tractor travelled with a front drive axle enabled and was engine braking with the fuel supply off. It was found that the variation in front and rear tires inflation pressure combination can significantly change the lead of the front drive wheels. For the tested tractor up to 6.9%. The result is that when the tractor travelled with the front axle enabled and was engine braking, the engine-braking efficiency decreases with increasing lead of the front wheels. Front (slipping) wheels create the opposite-direction torque, which is transferred to the rear wheels through the tractor's front-rear axle drive system. Additional losses of the engine braking occur in transmission due to power circulation, and the result is that the tractor wheels receive less braking torque from the engine. [ABSTRACT FROM AUTHOR]

The research included a standard study of the age of the which tires are (80%) and (50%) of standard condition and the inflation of the rear tire of the boat are (32) psi and (27) psi and the affect in both of the following properties(draft force, loss power to slippage, fuel consumption, effective field capacity, energy utilization efficiency, volume of soil disturbed, soil penetration resistance, dry bulk density) The experiment was carried out in a global experiment by using the Duncan test with experimental design (RCBD) was used to show the significance of the differences between the average transactions. The result showed a significant effect of the age of the tires in all the studied traits except for the description of the apparent density and showed a significant effect of the pressure factor of the tire bulge in all studied traits except of effective field capacity, volume of soil disturbed, dry bulk density. All the studied traits were significantly affected by the dual interference between the age of tires and pressure of bulge except for the dry bulk density which did not affect significantly. [ABSTRACT FROM AUTHOR]

Active tire pressure management, through an automatic, electro-pneumatic, central tire inflation system, is here proposed as a means of improving fuel consumption in passenger vehicles, as well as safety and drivability. A brief description of the active tire pressure control system, which has been set up at the Politecnico di Torino, is provided as a reference. Different strategies, aimed at reducing rolling resistance, through inflation pressure management, under specific vehicle working conditions, are then illustrated. The fuel benefits that can be achieved by adopting these strategies in passenger vehicles are studied by means of computer simulations using a proprietary software for vehicle performance and fuel consumption estimation. Coast-down coefficients, evaluated experimentally during deceleration tests on a closed track, are generally available at the reference tire pressure prescribed by the original equipment manufacturer of the vehicle. These fixed coefficients can then be used to describe the vehicle in simulation environments. LaClair's relation, which illustrates the influence of tire inflation pressure on rolling resistance, has therefore been used to recalculate the coast-down coefficients as functions of the tire pressure. This has allowed fuel consumption simulations to be performed on the reference B-segment passenger car under different working conditions. In particular, the following pressure management strategies have been studied: adaptation of the inflation pressure to the vertical load, variation of the inflation pressure during tire warm-up, and adjustment of the inflation pressure, according to the average speed (urban/highway driving). The performed simulations have demonstrated that if the standard tire pressure is maintained, fuel consumption could be reduced by up to 2% in real-world driving; further advantages could be obtained by varying the target pressure as a function of the current working conditions of the vehicle. [ABSTRACT FROM AUTHOR]

This paper presents a theoretical model for prediction of the stress state in agricultural soil under the agricultural tires of a heavy-duty tractor, using the Finite Element Method. Using an acquisition data system and pressure sensors, the theoretical model was experimentally verified in the laboratory. This study highlights the major advantage of using FEM models, which consists mainly in the spectacular reduction of costs for experimental testing and a considerable reduction in the time needed to analyse the possibility of the occurrence of artificial compaction phenomenon in the agricultural soil under heavy-duty tractors. [ABSTRACT FROM AUTHOR]