Traction Performance Research Articles

Measurement and Analysis of the Vertical Stress Distribution within a Cultivated Soil Volume under Static Conditions

Abstract. One of the important considerations of soil-tire interaction research is the stress distribution in the topsoil and within the cultivated soil volume due to tires. This stress distribution influences trafficability, ride performance, and tractive performance. In this study, a two-wheel-drive tractor and a group of piezoelectric pressure sensors were used at different tire loads and inflation pressures to (1) measure the vertical stress under three tire loads with three inflation pressures and determine the influence of these two parameters on the vertical stress in the topsoil, as measured by sensors with their upper surfaces at an initial depth of 50 mm within the soil volume; (2) develop an empirical relationship between the vertical stress and the depth beneath the soil surface, the tire load, the inflation pressure, and the lateral sensor distance from the tire centerline using multiple linear regression; and (3) analyze the effects of tire load and inflation pressure on vertical stress to contribute to the understanding of soil compaction processes based on the equation we developed. All vertical stress measurements were conducted when traffic was applied to the soil by the left front tire of the tractor, with forward motion of the tractor stopped before the left rear tire reached the sensors. The results indicated that (1) when the inflation pressure decreased, the soil-tire interface stress curve became smooth and the peak value of stress gradually moved to a point near the edge of the tire, whereas when the inflation pressure was higher, the peak stress value occurred in the center of the tire; (2) low inflation pressure significantly reduced the maximum vertical stress; (3) the vertical stress was influenced by all four factors investigated in this study; and (4) the stress within the soil volume varied as a quadratic function of the inflation pressure at a given tire load, and it varied as a linear function of tire load at a given inflation pressure. Keywords: Stress distribution, Tire load, Tire inflation pressure.

Design of active yaw controller integrated with ABS and TCS for multi-wheeled vehicles

Prodigious improvements have been attained in active vehicle safety systems region depending on different control systems. Active yaw control is one of these systems which target the vehicle stability in case of any rapid and/or severe manoeuvre. This paper presents the design of active yaw control system for (8 × 8) multi-wheeled vehicle and its integration with other safety control systems such as anti-lock braking system (ABS) and traction control system (TCS). A simplified vehicle model 'bicycle model' is employed to predict the desired vehicle yaw behaviour depending on road condition and driving situation. TruckSim-MATLAB/Simulink vehicle model was developed to verify the proposed integrated safety control system. The developed integrated active yaw controller with ABS and TCS succeeded in improving vehicle directional stability and traction performance. Furthermore, it should be mentioned that the road friction affects the controller efficiency as it limits the available braking torque to be used by the controller.

Расчет тягово-сцепных свойств движителя лесной машины при работе на заснеженной опорной поверхности

Расчет тягово-сцепных свойств движителя лесной машины при работе на заснеженной опорной поверхности

Enhancing the Passing Ability of Unmanned Vehicles Using a Variable-Wheelbase Driving System

A six-wheel driving system with a variable wheelbase is proposed to improve the passing ability of unmanned vehicles. As the first step, the effect of the wheelbase variation on the axle load distribution is analyzed. Next, the relationship between the wheelbase variation and rolling resistance is obtained by numerical calculation combined with the theory of terramechanics, and it shows that the traction performance of the vehicle can be optimized by adjusting the wheelbase. Considering the deformation of tires and soil, the mechanism of the effect of the change in wheelbase on the ability of the vehicle to overcome an obstacle and cross a trench is studied, and a variable-wheelbase strategy for a vehicle overcoming an obstacle and crossing a trench is then proposed on the basis of theoretical calculations. Finally, the rationality of the variable-wheelbase strategy is verified in simulation experiments.

Observer Synthesis for the Adhesion Estimation of a Railway Running Gear

The presented work illustrates an investigation on the observer synthesis for a highly nonlinear railway running gear system. The specific focus is on the longitudinal dynamics and the associated adhesion effects, i.e. the friction conditions between wheel and rail. This interface strongly influences the brake and the traction performance of trains and, thus, its detailed consideration is of crucial importance in terms of safety and comfort.The observer design is accomplished for the experimental running gear developed at the German Aerospace Center (DLR). The article focuses on the first steps of the observer synthesis: (i) the set-up of the observer model, (ii) the selection of an appropriate observer method, (iii) and the validation of the observer in a simulation environment. The determining aspect of the model implementation is the consideration of the nonlinear wheel-rail contact. To cover this nonlinear behavior an Extended Kalman Filter (EKF) is used in combination with a parameter estimator for the friction characteristics in the wheel-rail interfaces. In the end, the received results prove that the observer accurately estimates the system behavior and provides reliable information on the adhesion characteristics and related longitudinal dynamics.Based on this findings one of the upcoming steps at the DLR is to validate the observer in the real-time environment of the test rig. Regarding the use of the presented approach in a train some significant improvements of traction control systems are enabled. A first application could be an enhanced brake control to narrow down the variance of brake distances in daily operation. Furthermore, an advanced usability of the condition based monitoring of traction and brake systems is facilitated with the additional information on the friction conditions.

Design and Optimization of Traction IPMSM With Asymmetrical Damper Bars for Integrated Charging Capability Using Evolutionary Algorithm

The 3-phase windings of interior permanent magnet synchronous machines (IPMSMs) used in electric vehicles (EVs) for traction can also be utilized for charging a battery. This integrated charging technology eliminates the on-board charger, leading to a significant reduction in the overall weight and cost of the EV. However, during integrated charging, the induced magnetic fields across the IPMSM windings are unbalanced, which could lead to addition of harmonic current components at the battery side, demagnetization, noise, and vibrations. This paper provides a novel design solution by implementing asymmetrical damper bars in the IPMSM rotor to mitigate unbalanced magnetic fields during integrated charging, and, thus, overcome the aforementioned issues. However, the bars introduced could affect the useful torque production of the machine during traction. Therefore, a magnetic equivalent circuit model based differential evolutionary algorithm is proposed and implemented to optimize the IPMSM rotor structure with dampers to achieve balanced magnetic fields during integrated charging operation and satisfactory traction performance. A comprehensive performance analysis of the optimally designed traction IPMSM equipped with integrated charging capability under both operating conditions is presented in this paper using finite element analysis.

Modeling, kinematics and traction performance of no-spin mechanism based on roller-disk type of traction drive continuously variable transmission

Modeling of no-spin mechanism based on roller-disk type of traction drive continuously variable transmission (t-CVT) is conducted by redesigning the working generatrix of the original disk to meet the no-spin condition, and a novel basic no-spin Conical CVT mechanism is acquired. According to the structural characteristics of Half Toroidal CVT(HT-CVT), the no-spin Swing Conical CVT(NSC-CVT) and no-spin Rolling Conical CVT(NRC-CVT) are developed by configuring the structural symmetry and speed changing motion form of the no-spin Conical CVT. Furthermore, the kinematics of NSC-CVT is studied and compared with HT-CVT. The result demonstrates that the actual spin ratio of the NSC-CVT are smaller than that of HT-CVT, and the half cone angle of NSC-CVT is recommended. At last, a computational method has been proposed to compute the efficiency of the NSC-CVT. Comparing with HT-CVT, the better efficiency is achieved by the NSC-CVT, whereas the advantage of no-spin characteristic is proved. But the torque capacity of NSC-CVT is not as good as that of HT-CVT, which will limit its use to high torque applications.

Application of a 3D tractor-driving simulator for slip estimation-based path-tracking control of auto-guided tillage operation

Successful adoption of auto-steering agricultural vehicles in Korean paddy fields depends on the ability to accurately follow a full path, including straight and curved paths for agricultural tasks and headland turning in each row, in the presence of sliding caused by wet ground conditions in relatively small fields. To improve the performance of an autonomous tillage tractor originally developed in our previous study, this article describes a simulation study, conducted using a 3D computer simulator, that accounts for the slippery motion of a virtual tractor on ground with varying adherence properties, In addition, this study performed field evaluation of an auto-guided tillage tractor equipped with a slip estimation-based path-tracking algorithm that is robust to slippage in paddy fields. The test platform was built with a 60-kW tractor equipped with an RTK-GPS (real-time kinematic-global positioning system) and IMU (inertial measurement unit) system, a navigation controller that could estimate the sideslips of the tractor in real-time, and a three-point hitch dynamometer that could measure tillage drafts. The results of the computer simulation confirmed that the slip estimation-based path-tracking algorithm was superior in guiding the tractor along curved paths on the ground with relatively low coefficients of cornering stiffness by reducing the lateral deviations as compared with those obtained with the conventional look-ahead distance method. In field tests run in an arable field, the autonomous tillage tractor equipped with the slip observer algorithm demonstrated improved performance as compared to the previously developed system by reducing the RMSE (root mean square error) for lateral deviation on curved paths from 29 cm to 15 cm.

Refurbishment and evaluation of a two-wheeled tractor

The refurbishment of GUTBROD-WERKE/80 two-wheeled tractor for better functioning and subsequent field performance evaluation was carried out. Physical and mechanical inspections were done to ascertain the state of the tractor. The observed faults were; rusted and stuck carburetor, damaged induction coil, rusted fuel control, stuck wheels, worn out tires, and no implement attachment base. The faults were corrected by designing coupling flanges for implement attachment; replacement of carburetor and worn-out parts. The tractor was tested by conducting a field evaluation using standard equations and procedure. The results obtained showed that the field efficiency and effective field capacity were 61.50%, and 0.032ha/hr respectively. The fuel consumption was 0.43L/hr at a depth and width of cut of 8.94cm and 27.46cm respectively at an average soil moisture content of 13.2%. The implement draft and drawbar pull were 1.13kN and 0.43kW respectively. The tractor performance shows its suitability for small farm work.Keywords: two-wheel tractor, refurbishment, effective field capacity, field efficiency

Determining the Traction Characteristic of a Tractor in Operating Conditions

One of the most important aspects in terms of increasing the efficiency of agricultural production is the improvement of the methods and tools of determining the main operating indicators of tractors as they influence the productivity, efficiency and ecological safety of machine­tractor units. (Research purpose) To develop a method for obtaining traction characteristics of a tractor, which make it possible to reduce the time needed for measurements under operating conditions, and to design an instrument for economical obtaining of tractors’ traction characteristics under specific farm conditions. (Materials and methods) the authors have chosen a method for determining the energy performance of tractors under operating conditions in a transient mode. They have conducted traction tests of tractors for various modes and soil backgrounds to evaluate its traction­dynamic and fuel­economic indicators. The traction characteristic of a tractor is the dependence of the tractor performance (traction power, speed, hourly and specific fuel consumption, and slipping) on the load at various speeds against a given soil background. However, traction tests require expensive equipment, as well as significant costs and time to prepare and conduct, which leads to their implementation only in the conditions of machine testing stations. (Results and discussion) The authors have developed a method for obtaining traction characteristics of a tractor under operating conditions. Instantly increasing the fuel supply to the maximum, during the tractor acceleration, the engine crankshaft speed and track­measuring wheel were measured at a given speed and against the corresponding soil background ­ with load and without load. It has been revealed that the fuel and economic indicators can be determined using cyclical fuel supply by the fuel pump at the maximum mode on the bench for checking and adjusting the fuel equipment. The authors have developed and assembled a measuring and computing installation that allows processing arrays of data from two inductive sensors. (Conclusions) The proposed method for determining the traction­dynamic and fuel­economic indicators of tractors and the measuring­computing installation that implements it allow obtaining a traction characteristic (speed, slipping, traction power, hourly and specific fuel consumption depending on the load at various speeds against a given soil background) in operating conditions, thus reducing the time and cost of operation.

Performance of tractor operated two row sugarcane cutter planter for sugarcane planting in Andhra Pradesh State, India

Sugarcane is an important agro-industrial crop requiring more labour force for planting. Presently, in traditional cultivation of sugarcane, all the operations are being done manually or semi mechanized stage, 60 per cent of the cost incurred towards labour charges. Sugarcane planting involves cutting of setts, opening of furrows, placing the setts in furrows and covering the setts with soil which is tedious, time consuming process and labour intensive. Introduction of mechanized planter will perform all these operations simultaneously and reduce dependency on labour and complete the farm operations in time. A field experiment was conducted at Regional Agricultural Research Station, Anakapalle, Andhra Pradesh to evaluate the performance of tractor mounted two row sugarcane cutter planter. The field capacity of the equipment was found to be 0.16 ha/h. The biometric parameters viz., diameter of the cane, height of the cane and yield of mechanically planted sugarcane was on par with the manually planted sugarcane where as single cane weight and root spread area were found to be significantly different (p<0.05). Similarly, the juice quality of mechanically planted sugarcane in terms of degree Brix, sucrose per cent was on par with conventionally planted sugarcane. Economic analysis revealed that cost of planting with sugarcane cutter planter was Rs.15,400 per ha as against Rs. 6750 with traditional method of planting. The saving in labour cost, seed quantity and planting time with sugarcane cutter planter were to the tune of 51 per cent, 68 per cent and 58 per cent, respectively compared to conventional method of planting.

Effect of Calcium Chloride as a Coagulant on the Properties of ESBR/Silica Wet Masterbatch Compound.

When designing rubber compounds for high-performance tires, increasing the silica content can improve the wet traction performance but decreases the fuel efficiency. This trade-off relation makes it difficult to improve the two factors simultaneously. One approach is the development of silica wet masterbatch (WMB) technology for producing compounds containing a high silica content with good dispersion. The technology involves a step to mix surface-modified silica and rubber latex. The technique requires a coagulant to break up the micelles of the rubber latex and cause the surface-modified silica and the rubber molecules to co-coagulate due to van der Waals forces. In this study, the effect of coagulant type on the characteristics of silica surface, and the mechanical properties of the emulsion styrene-butadiene rubber (ESBR)/silica WMB compounds was investigated, as well as the abrasion properties and the viscoelastic properties of the vulcanizates.

Experimental Investigation of the Tractive Performance of Pneumatic Tires on Ice

ABSTRACTThis investigation was motivated by the need for performance improvement of pneumatic tires in icy conditions. Under normal operation, the pneumatic tire is the only force-transmitting component between the terrain and the vehicle. Therefore, it is critical to grasp the understanding of the contact mechanics at the contact patch under various surfaces and operating conditions. This article aims to enhance the understanding of the tire-ice contact interaction through experimental studies of pneumatic tires traversing over smooth ice. An experimental design has been formulated that provides insight into the effect of operational parameters, specifically general tire tread type, slip ratio, normal load, inflation pressure, ice surface temperature, and traction performance. The temperature distribution in the contact patch is recorded using a novel method based on thermocouples embedded in the contact patch. The drawbar pull is also measured at different conditions of normal load, inflation pressure, and ice temperatures. The measurements were conducted using the Terramechanics Rig at the Advanced Vehicle Dynamics Laboratory. This indoor single-wheel equipment allows repeatable testing under well-controlled conditions. The data measured indicates that, with the appropriate tread design, the wheel is able to provide a higher drawbar pull on smooth ice. With an increase in ice surface temperature, a wet film is observed, which ultimately leads to a significant decrease in traction performance.

Performance analysis and test of a maize inter-row self-propelled thermal fogger chassis

In view of the difficulties in weeding and plant protection in the middle and late period of maize planting, this paper proposed a self-propelled thermal fogger chassis. According to the theoretical calculation and agronomic requirements for maize planting, the structure and working principles of the self-propelled thermal fogger chassis were introduced. On this basis, the multi-body dynamics model of chassis structure was established, and the chassis traction, steering and obstacle surmounting performances were also analyzed. Then the rationality and the feasibility of the design were verified through the furrow running test and test equipped with thermal fogger. Test results showed that, the traction performance improves with the decrease of soil deformation index and increase of cohesion, and when track pre-tensioning force was about 1000 N, the machine had a good traction performance; with the decrease of the soil deformation index and the increase of cohesive force, the stability of the single side brake turn of the chassis becomes better; on the contrary, with the increase of the tightness of the crawler, the steering radius turns smaller and the steering stability becomes worse. Under heavy clay, with the pre-tensioning of 1000 N, the machine has better steering stability and smaller turning radius. The obstacle-surmounting simulation result shows that on sandy soil road, the maximum climbing angle for the chassis is 42°, the height of vertical obstacle crossing is 170 mm and the trench width is 440 mm. The study provides a reference for the design of plant protection machinery in the middle and late stages of maize planting. Keywords: maize inter-rows, intelligent chassis, traction performance, steering performance, obstacle surmounting performance DOI: 10.25165/j.ijabe.20181105.3607 Citation: Chen L Q, Wang P P, Zhang P, Zheng Q, He J, Wang Q J. Performance analysis and test of a maize inter-row self-propelled thermal fogger chassis. Int J Agric & Biol Eng, 2018; 11(5): 100–107.

TRACTOR PERFORMANCE IN SOWING WITH FURROWER CONFIGURATIONS IN AREAS WITH CONTROLLED TRAFFIC OF MACHINES

ABSTRACT The controlled traffic of machines is a technique that performs the standardization of machine wheel gauges and width of implements, allowing them to move in predetermined places. The objective of this study was to evaluate the performance of an agricultural tractor, pulling seeder with configurations of furrows, in an area with controlled traffic of machines in various intensities. The study was developed in an agricultural area located in the municipality of Carazinho, RS. The experimental design was 3 × 3 randomized blocks, with traffic conditions (tractor traffic, tractor and harvester traffic, other tractor traffic, harvester and sprayer) and three configurations of furrows (double disk, double disk in the rows without traffic and rod in the traffic and double disk in the rows without traffic and without furrower in the lanes of traffic). The variables analyzed were traction force, power in the drawbar, maximum power, speed, skidding, operational capacity and efficiency of the engine. It was concluded that the absence of furrows in controlled traffic lanes provides reduction of traction force. The power demand of the seeder decreases when the rod-type furrow is replaced by double disc and this reduction is even greater when removed from the traffic lanes in situations of higher traffic intensity.

Development and implementation of a human machine interface-assisted digital instrumentation system for high precision measurement of tractor performance parameters

A high precision compact digital instrumentation system was developed to display, collect, and store desirable tractor performance parameters. The system was designed based on the technical capabilities of human machine interface (HMI) technology. A touch screen user friendly HMI-assisted data acquisition unit was developed to control different procedures of the system for continuous measurement of the tractor performance parameters (driving wheel slip, forward speed, fuel consumption, working depth, and required draft force or drawbar pull of implement) with data collection rate of 90 Hz. Commercial transducers used to develop the system were calibrated for desired measurements. The system was mounted on an agricultural diesel tractor (MF-399) and assessed under static and dynamic conditions. Results of calibration trials indicated a high correlation between actual and measured variables. Maximum errors of less than 5% for stationary assessment of the instrumented tractor in two-wheel drive (2WD) and four-wheel drive (4WD) modes proved an acceptable accuracy of the system. Satisfactory operational efficiency of the system under dynamic field conditions resulted in quick response to small changes of the tractor performance parameters. The system is flexible enough to be easily integrated on any 2WD or 4WD tractor. Practically, the system would be very useful for experimental practices, educational and research studies.

Influence of Natural Wear Progression on Shoe Floor Traction – A Pilot Study

Slips and falls in the workplace are a major concern for injuries. Worn shoes are a known risk factor for slips and falls. The purpose of this pilot study was to analyze changes in shoe traction performance under fluid contaminant conditions as the shoes were progressively worn. Four subjects wore two different shoes with varying tread patterns. Shoes were tested after each month of wear. The two types of shoes responded to wear differently; one shoe experienced a substantial decrease in available coefficient of friction (ACOF) while the other shoe showed no substantive change. Loads supported by the fluid during slipping increased with wear of the shoes. Furthermore, ACOF was influenced by the shoe type and the walking distance. This study suggests that the impact of wear on shoe performance is dependent on the shoe design. Thus, future studies are needed to understand specific effects of shoe design.

Mobility Range of a Cable Skidder for Timber Extraction on Sloped Terrain

The use of forestry vehicles in mechanised harvesting systems is still the most effective way of timber procurement, and forestry vehicles need to have high mobility to face various terrain conditions. This research gives boundaries of planning timber extraction on sloped terrain with a cable skidder, considering terrain parameters (slope, direction of skidding, cone index), vehicle technical characteristics and load size (5 different loads) relying on sustainability and eco-efficiency. Skidder mobility model was based on connecting two systems: vehicle-terrain (load distribution) and wheel-soil (skidder traction performance) with two mobility parameters: (1) maximal slope during uphill timber extraction by a cable skidder based on its traction performance (gradeability), and (2) maximal slope during downhill timber extraction by a cable skidder when thrust force is equal to zero. Results showed mobility ranges of an empty skidder for slopes between −50% and +80%, skidder with 1 tonne load between −26% and +63%, skidder with 2 tonne load between −30% and +51%, skidder with 3 tonne load between −34% and +39%, skidder with 4 tonne load between −35% and +30% and skidder with 5 tonne load between −41% and +11%.These results serve to improve our understanding of safer, more efficient timber extraction methods on sloped terrain.

DYNAMIC PROPERTIES AND TIRE PERFORMANCES OF COMPOSITES FILLED WITH CARBON NANOTUBES

ABSTRACT Carbon nanotubes (CNTs) have been widely studied in rubber goods and tire compounds to improve, for example, antistatic and thermal conductivity performances. CNTs were applied in passenger tire tread compounds to improve comprehensive tire performances, especially wet traction. High frequency dynamic properties of CNT-filled compounds were revealed for the first time. There was good correlation between compound dynamic properties and vehicle tire test results. The influence of CNTs on tire performances and their mechanisms was investigated and explained by the dynamic properties and master curve analysis in the frequency domain. Substituting 50 phr carbon black N234 by 20 phr CNTs could maintain hardness but increased static and dynamic moduli, which was beneficial for the tire handling, with 0.25 point improvement in the subjective testing. For the CNT-filled compounds, 1.5% traction improvement on a dry road and 6.5% traction improvement on a wet road can be explained successfully by the increased hysteresis loss (tan δ) and decreased storage modulus (G′) at high frequency domain (104–108 Hz). It is implied by Williams–Landel–Ferry law calculation that a strong interaction between CNTs and rubber resulted in higher temperature dependence; however, the trade-off was a 7% higher tire rolling resistance coefficient and 33% worse wear resistance for the CNT tires. CNT-filled compounds were demonstrated to have superior handling and traction performances suitable for racing and sports car tires.

Effects of Murumuru (Astrocaryum murumuru Mart.) and soybean biodiesel blends on tractor performance and smoke density

Effects of Murumuru (Astrocaryum murumuru Mart.) and soybean biodiesel blends on tractor performance and smoke density