2WD Tractor Research Articles

Development and implementation of a raspberry Pi-based IoT system for real-time performance monitoring of an instrumented tractor

The tractor serves as a crucial power source in agricultural operations. However, the tractor's power often remains underutilized due to a mismatch between the tractor and implement, considering specific field conditions. To enhance system output, it becomes vital to acquire data on performance-related parameters for the tractor-implement combination. In this study we develop a real-time Instrumented Tractor Performance Monitoring System (ITPMS) using the Internet-of-Things (IoT). This system consists of a Raspberry Pi, a GPS sensor, a proximity sensor, a rotary potentiometer, and a three-point hitch dynamometer. The rotary potentiometer measures tillage depth, while the three-point hitch dynamometer used to measure data on draft force. Proximity sensors are installed on a two-wheel drive (2WD) tractor to measure forward speed and drive-wheel slip. We establish a dedicated web server using a Google® Firebase® project to store data from all sensors through Raspberry Pi. Additionally, we design a web interface and a mobile application to provide real-time data generated from the sensors. Field experiments were done to evaluate and monitor the performance parameters of the tractor-implement combination utilising the developed ITPMS. The results demonstrate that the system effectively monitors the performance parameters necessary for tractor-implement combination. Furthermore, the system's capability to update data to the IoT server in real-time is validated. Overall, the development and implementation of this Raspberry Pi based IoT system, provides a reliable and efficient solution for real-time performance monitoring of instrumented tractors.

Development of PTO torque transducer based on an embedded digital wireless system for the 2WD tractor

Development of PTO torque transducer based on an embedded digital wireless system for the 2WD tractor

Definition of linear regression models to calculate the technical parameters of Italian agricultural tractors

As it is known, the modern agricultural tractor is no longer just a machine capable to pull agricultural trailers and to operate implements but has evolved into a multi-purpose and mobile energy source with standardized interfaces (mechanical, hydraulic and electronic) to connect to a several typologies of agricultural operating machines. It follows that the selection of the most appropriate tractors for the specific production realities is a crucial aspect for farmers, advisors, contractors and farm machinery experts. The tractors choice thus must consider different parameters, concerning not only the cost of the machines but also their dimensions, power, weight, technological level, etc. The availability of simplified models for estimating the purchase investment and sizing the machine in relation to its mechanical characteristics could be a useful tool in the choice of the tractor more suitable for the specific agricultural context. The aim of this study was to collect and to analyse the technical parameters of tractors present on the Italian market (more than 1300 models), divided into: i) four wheel-drive (4WD) standard tractors, ii) two wheel-drive (2WD) standard tractors, iii) narrow track 4WD tractors, iv) Isodiametric specialized 4WD tractors, v) crawler tractors and vi) rubber-tracked tractors), in order to define the most relevant parameter-to-parameter and parameter-to-price relations for updating reference models to calculate the machine price and the weight to engine power ratio. Other relations, including the three-point hitch efficiency with respect to tractor’s weight and the relationship between the rated engine power and its displacement, are proposed in order to provide synthetic tools to characterise and to compare - from the mechanical point of view - the different categories of agricultural tractors.

Assessment of the Performance of Agricultural Tires Using a Mobile Test Bench

The performance of agricultural tires varies with the characteristics of both the terrain and the tractors on which they are mounted, which differently affect the rolling resistance, the traction capacity, and the slip. To reduce the variability of test conditions, CREA developed an original mobile test (MTB) bench which consists of a dynamometric single axle trailer pulled by a tractor and can be used both in traction performance tests (driving wheels) and in rolling resistance tests (driven wheels). A control system alternatively operates the adjustment of traction force or slip, so that each test is performed maintaining constant the desired values. The MTB underwent tests under different conditions (type of surface, pre-set values of force of traction and slip) aimed at verifying its accuracy and reliability. In a final test, two pairs of identical new tires were simultaneously mounted on the MTB and on the rear axle of the 2WD tractor that pulled it, to discover information on the different interactions occurring, under the same traction conditions, between the soil surface and each pair of tires, with reference to the relationship between the slips and the load transfers observed on the MTB and on the tractor rear axle. The results evidenced the capability of the MTB to guarantee repeatable test conditions, including field conditions, allowing comparison among the performance of different tires.

Tyre Configuration and Axle Load of Front-Wheel Assist and Four-Wheel Drive Tractors Effects on Soil Compaction and Rolling Resistance under No-Tillage

Selecting the appropriate tyre configuration and settings for heavy farm vehicles is important to ensure that soil compaction and power loss in rolling resistance are minimised and traction is optimised. This study investigated the effect of front-wheel assist (FWA, ≈75 kN) and four-wheel drive (4 WD, ≈100 kN) tractors fitted with different tyre configurations (single, dual), tyre sizes and inflation pressures on soil strength (a proxy for soil compaction), and rolling resistance. Single-pass tests were performed on a Typic Argiudoll (≈23% clay, bulk density: 1305 kg m−3) managed under permanent no-tillage. Results showed that average power losses in rolling resistance were 7.5 kN and 5 kN for the 4 WD and FWA tractors, respectively. The average rut depth increased by approximately 1.4 times after a pass of the 4 WD compared with the FWA tractor. The soil cone index (0–600 mm depth) increased from 2023 kPa (before traffic) to 2188 and 2435 kPa after single passes of the FWA and 4WD tractors, respectively (p < 0.05). At the centreline of the tyre rut, dual tyres reduced the soil cone index a little compared with single tyres, but they significantly increased the volume of soil over which soil strength, and therefore soil compaction, was increased. For both tractors (regardless of tyre configuration or settings), soil strength increased to the full measured depth (600 mm), but relative changes before vs. after traffic became progressively smaller with increased soil depth. The power loss in rolling resistance was consistently greater with the heavier tractor, and rut depth was directly related to tyre inflation pressure.

Development and Evaluation of Automated Slip and Draft Control System for Tractor

A microcontroller-based Automatic Slip Control System (ASCS) and Automatic Draft Control System (ADCS) for 2WD tractors was devised to automatically alter the depth of operation to keep the wheel slip and implement draft within a pre-specified range. An electro hydraulic lift link system was devised to control the depth of the implement's operation. The technology continuously checks wheel slip and draft in the field and notifies the hydraulic system, which changes the implement's depth if the wheel slip and draft exceeds the specified range. Experiments were conducted with defined slip ranges of 10–15, 15–20, and 20–25% for ploughing and cultivating activities. Field capacity and drawbar specific fuel consumption were measured as performance criteria. With the ASCS, the slip was found to range from 15–24%, versus the desired range of 15–20%, while with the current draft control system, it was found to range from 12–48% Tractor Draft Control System (TDCS). Fuel consumption was determined to be 20.13, 21.11, and 22.98 l/ha for ploughing operations with TDCS at initial depth settings of 150, 180, and 220 mm, respectively. However, ASCS resulted in a significant increase in fuel efficiency, with an 11.2% reduction in consumption. When compared to the TDCS, it consumed 4 to 14% less fuel during ploughing operations. Field capacity was increased by 3.4–14.5% due to ASCS and ADCS. The measuring efficiency of the devised system was determined to be greater than 99%.

Prediction of Specific Fuel Consumption of 60 HP 2WD Tractor Using Artificial Neural Networks

In this study, specific fuel consumption was determined at different axle load, tire pressure and drawbar force for a 60 HP tractor. In addition, the results were also estimated with the help of Artificial Neural Networks (ANN), which is one of the machine learning methods. The testings were carried out on the Tractor Draft Test Track. In the study; three different drive tire inner pressures (P) (160 kPa, 120 kPa and 80 kPa), four different dynamic axle loads (W) (1796 daN, 2076 daN, 2276 daN, 2476 daN) and four different traction forces (500 daN,1000 daN, 1500 daN, 2000 daN) were tested. Specific fuel consump-tion values varied between 290.7-542.1 g/kWh depending on the draft force in the testings Despite the 38% increase in the axle load, a 3.5% decrease occurred in the specific fuel consumption values. Specific fuel consumption values in-creased when increased tire inner pressure. Specific fuel consumption in-creased by 1.03% when a 100% increase in tire pressure. In ANN, the most suc-cessful 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 consump-tion were found to be 0.005331, 0.007551 respectively.

Improving the performance of a ploughing tractor by means of an auxiliary carriage with motorized axle

The article describes the analysis of results from field tests on ploughing units based on a modular draft device (MDD). This device is named MDD-100 and consists of an energy module and a technological module. The energy module is a universal tractor with a rated draft resistance of 16 kN. The technological module is an additional axle, equipped with an active wheel drive, a threepoint hitch linkage, and a saddle-type semi-trailer. During the working process, the draft resistance of the energy and the technological modules of the MDD-100 add up. As a result, the draft resistance of the latter may reach 26 kN, and more. This allows the MDD-100 to be classified as a draft device in traction class 3 and be used with agricultural machines with a large working width. The MDD-100 was tested with a five-bottom mounted plough with a working width of 1.75 m and a draft resistance of 24-28 kN. The best option for driving the MDD-100 with a plough was its movement with the right-side wheels in the furrow. The draft resistance of the plough would decrease by 12.0%, if the option of the MDD-100 outside the furrow is used. This ensured a 12.8% reduction in the skidding of the MDD-100 wheels and a 13.1% decrease of fuel consumption for the ploughing unit. Compared to a 4WD tractor, the use of a modular draft device with a 6WD wheel arrangement offered a greater stability of the ploughing depth.

Mechanical Devices for Mass Distribution Adjustment: Are They Really Convenient?

Since the introduction of four-wheel drive (4WD) and especially front wheel assist (FWA), many studies have been conducted on the optimal weight distribution between tractor front and rear axles because this influences traction efficiency. The aim of this paper is to evaluate the traction and efficiency advantages in the adoption of mechanical ballast position adjustment devices. The tested device is an extendable ballast holder mounted on the front three-point hitch of the tractor, able to displace the ballast up to 1 m away from its original position. An estimation of the fuel consumption during ploughing with the extendable ballast holder in different configurations was performed. Tractive performance was evaluated through drawbar tests, performed on loam soil with a 4WD tractor having a maximum engine power of 191 kW and a ballasted mass of 9590 kg. Results show that changing the tractor weight distribution over the range allowed by the extendable ballast holder produces limited effects in terms of tractive performance and fuel saving. The adoption of such devices is thus ineffective if other fundamental factors such as tyre pressure, choice of the front-to-rear wheel combination and lead of the front wheels are not considered during tractor setup.

Effect of hitch distance on haulage performance for 2WD tractors: A theoretical analysis

Aim of study: A computer program was developed in Visual Basic 10 environment for predicting the haulage performance of 2WD tractors using various empirical and theoretical equations.Methodology: Three types of inputs related to tractor, trailer and operating parameters were used to calculate the performance parameters through empirical and theoretical equations. The performance parameters included mainly draft, slip, transport efficiency, transport productivity, fuel economy index, rear and front axle dynamic weight, etc. The program was used to evaluate the haulage performance by varying hitch distance (HD) at various operating conditions.Main results: On one hand lower HD was beneficial in increasing the maximum payload, transport productivity as well as the maximum slope; but at the same time, it reduced the rear axle dynamic load, fuel economy index and actual engine power requirement.Research highlights: There was a markable effect of HD over tractor performance which can play a role to optimize traction and stability.

HAVE TRACTOR MANUFACTURERS BORE IN MIND SOIL COMPACTION OVER THE LAST 40 YEARS?

Soil compaction is the compression of soil particles in a lower volume as a consequence of the reduction of the spaces existing among the particles themselves. This phenomenon is caused by natural forces and, above all, human ones. In order to estimate the field damages that can be caused by the traffic of agricultural machines, the load and the mean pressure applied by the tyres onto the soil can be measured. The research aim is to determine the pressure applied by each considered tractor onto the soil, in order to evaluate the effect of the traffic of tractors onto the soil itself. A total of 783 wheeled tractors manufactured and marketed in the last 35 years (1979-2014) were investigated. Data like construction year, manufacturer, model, power, total weight, weight (load) on the front and rear axle, wheelbase, front and rear type of tyres, as well as the tyre specifications, were collected. The mean pressure applied by each tractor onto the soil was computed by dividing the load applied on each tyre by its contact area. In order to reduce the pressure applied by agricultural machines onto the soil, the vehicle mass and, therefore weight, has to be reduced, or the tyre contact area on the soil has to be increased. Farmers can easily increase the tyre contact area, by decreasing the tyre inflation pressure or increasing the tyre width, i.e. mounting tyres having a larger section width, or Terra Tyres, or twin-tyres. Over the last 40 years: the mean power of mechanical four wheel drive (MFWD) tractors and four wheel drive (4WD) (isodiametric tyres) tractors increased, while that of two wheel drive (2WD) tractors remained constant; the power and the total weight increased, while the weight-power ratio decreased. Practically the reduction of the mean pressure on the soil resulted rather limited, meaning that tractor manufacturers have not bore in mind soil compaction.

Effect of Hitch Height on Wheel Slip and Stability of 2WD Tractor

A S-type load cell was installed below the front axle of a 2WD tractor to record the dynamic load of the front axle. The load was recorded with the help of a data logger (DT800). Theoretical and actual speeds of the tractor were measured with proximity sensor and non-contact type radar sensor, respectively to calculate the wheel slip. The test was conducted on two types of road surfaces namely tarmacadam surface with slopes of 0°, 3.4° & 4.8° and unpaved surfaces with slopes of 0°, 2.86° and 5.61° with payload of 2, 2.5 and 3 tons on trailer at hitch heights of 45, 55 and 60 cm above the ground. It was observed that dynamic load on the front axle and slip decreases from 603 kg to 438 kg and 8.65 to 5.49 %, respectively on raising the hitch height from 45 cm to 60 cm above the ground at a payload of 2 tons on the trailer. Similar results were obtained on all payloads at different slopes and road surfaces. Lowering the hitch height resulted in the reduction of weight transfer from the front to the rear axle from 32 to 7 % of the static weight of the front axle thereby improving the stability of the tractor.

Automatic tractor slip-draft embedded control system

A microcontroller-based embedded system for automatic slip-draft control was designed, developed and tested for a 2WD tractor. The system synchronously measures and controls the wheel slip and implement′s draft closer to the set ranges under varying field conditions. Actual and theoretical speeds were digitally acquired through the controller-Hall Effect combination employed on front and rear wheels for the digital accession of the wheel slip. Implement draft was recorded using a three-point linkage dynamometer placed between the tractor and implement. The developed system was evaluated with test tractor and analogized with the existing draft control system. A maximum slip variation of 2% was witnessed between the computed and the indicated values in the developed system. The novel intelligent slip-draft control system also amounted to improve the tractive performance of 9.17% and 6.05% during ploughing and harrowing respectively when analyzed against an existing draft control system. It also minimizes operator fatigue and improves the operation efficiency resulting from a minimum intervention for depth and draft control under dynamic field conditions.

Effect of Ploughing Depth, Tractor Forward Speed, and Plough Types on the Fuel Consumption and Tractor Performance

Cost of fuel has a significant impact on the input costs of agricultural production, especially during primary tillage. It is affected by several parameters including tractor forward speed, depths of ploughing, and plough types. The experiment was performed in a Soil Hall at Harper Adams University, United Kingdom, in April 2015. A Massey Ferguson 8480 4WD tractor was used for investigating objectives of this study. The experiment was performed in a sandy loam soil texture at 11.73% soil moisture content and 1.35 (g/cm3) dry bulk density to study the amount of fuel consumption (l/ha) and the performance of tractor with effect of moldboard and disc ploughs as ploughs type, 15 and 20 cm as ploughing depth and 5 and 7 km/h as tractor forward speeds. The results showed that fuel consumption with a disc plough 5% was higher compared to the moldboard. Fuel consumption decreased approximately 8% when tractor at 7 km/h. Fuel consumption significantly decreased about 34% when ploughing depth increased from 15 to 20 cm. The power requirement to operate moldboard plough was higher by about 14% than a disc. The power requirement at speeds of 7 km/h was higher compared to the speeds of 5 km/h by about 27%. When the depth of ploughing increased from 15 to 20 cm, the power requirement increased by about 1.5%.

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.

Embedded digital drive wheel torque indicator for agricultural 2WD tractors

A microcontroller based embedded system was developed to measure and display the dynamic wheel axle torque and drawbar power of agricultural tractor for tillage research. The device includes a special transducer to measure dynamic drive wheel torque of tractor, an embedded wireless digital system to receive process and display data digitally as well as record in SD card module near the dash board of the tractor. The embedded system mainly consists of an amplifier to amplify the transducer signal, a transmitter unit to process the amplifier data, and a receiver unit to receive and display the transmitter unit data. The developed system was rigorously tested under laboratory and actual field conditions. It was found that, a maximum variation of ±320Nm torque between the theoretically calculated and experimentally observed values under field conditions. With the developed devices the real time power requirement of various agricultural operations could be known to help the tillage researchers. The developed device and systems are simple and accurate and can be used for any range of agricultural tractors.

A visual basic program for predicting optimum gear and throttle position for best fuel economy for 32 kW tractor

A visual basic program was developed to determine the optimum gear and throttle position on the basis of minimum fuel consumption per hectare for ploughing, cultivating and harrowing operations. The program provides an intuitive interfaces by linking database such as tractor, tyre and implement specifications, draft and tractions model constants, fuel consumption model, soil and operating conditions to predict the minimum fuel consumption of selected model. The fuel consumption model was developed by conducting PTO test under variable throttle and load conditions. The coefficient of determination (R2) value for developed model was found close to 0.99. The program was validated with the data collected from the field experiments conducted with a 32kW PTO power 2WD tractor and 2-bottom reversible MB plough under different operating conditions. It was found that the developed program predicted optimum gear as L3 (6.9km/h) at 2066rpm and on an average under predicted slip values by 50–62%, draft by 4–20% and over predicted fuel consumption by −19 to 52% in the depth range of 18–22cm.

Importance of automatic variable single hitch point for 2WD tractors – A theoretical analysis

Software is developed in Visual Basic 6 environment for predicting the haulage performance of 2WD tractor. Three types of inputs namely tractor, trailer and operating parameters are required to run the software. Various empirical and theoretical equations were used for predicting the haulage performance parameters such as draft, slip, actual speed, transport productivity, transport efficiency, fuel economy index, front and rear wheel utilization factor etc. In addition to this, the software also gives a warning signal when either stability of tractor or engine power fails. It was used to evaluate the haulage performance by varying the hitch height (HH) at various operating conditions. It was observed that there is a significant increase in the maximum payload 78, 300 and 3300% while HH was lowered from 0.7 to 0.1 m at 0, 5 and 10° slope, respectively. However, the dynamic load on rear axle increased from 1470 to 1730 and 1500 to 1820 kg when HH increased from 0.1 to 0.7 m at 800 and 1000 kg payload, respectively. Further, it was observed that fuel economy index was reduced by 6.3% and engine power requirement by 4.23% at 800 kg payload when HH was raised from 0.1 to 0.7 m. It was observed that stability of tractor increases by lowering the HH, however, traction increases by raising the same. Hence, it was concluded that variable HH can meet the requirements of stability as well as traction during transport as per necessity.

Influence of Extra Weight and Tire Pressure on Fuel Consumption at Normal Tractor Slippage

Tire pressure and wheel load are both easily managed parameters which play a significant role in tillage operations for limiting slip which involves energy loss. To a great extent, this aspect affects the fuel consumption and the time required for soil tillage. The study was focused on the tire pressure and extra weight variation effect on fuel consumption and work productivity for soil tillage at normal tractor wheels slippage (7-15%). The experimental research unit composed of an 82.3 kW 4WD tractor and a reversible 4-bodies plough is presented. Tests were carried out on a stubble loam, where slip of tractor driving wheels was < 15%, tractor front ballast mass was varied in the range from 0 to 520 kg and inflation pressure in the tires from 240 kPa to 100 kPa. Dependences of tractor performance indicators on ballast mass and tires inflation pressure are presented. When tractor tire slip varies in the range from 7 to 15 percent (which is normal slip in the soil), reducing the tires inflation pressure decreases the driving wheel slip and fuel consumption, while increases work productivity. Increasing the additional mass of the tractor (adding ballast weights) decreases the driving wheel slip, increases work productivity, but also increases fuel consumption and soil compaction.

How driving wheels of front-loaded tractor interact with the terrain depending on tire pressures

This paper analyzes peculiarities of wheel interaction with the terrain for 4WD tractors working with front-mounted loaders. When tractor wheels are loaded by a vertical forces that do not correspond to the specified proportions, deformations of front and rear tires also do not correspond to the specified proportions, and this leads to a kinematic discrepancy because of change in ratio between driving wheels’ rolling radiuses. In case of kinematic discrepancy, wheel slip/skid is taking place. In the paper test results are presented, how driving wheels’ slip/skid of 4WD tractors with front-mounted loaders depend on the vertical loads acting on the wheels and their tire inflation pressures. It was determined that there are dependences on relation between front and rear tire pressures, which allow avoiding wheel slip/skid for the 4WD tractor with front-mounted loader that runs without a load and transports loads. By preparing a tractor for work with front-mounted loader, it is advisable for operator to select a set of tires that would ensure the lead of front wheels lesser compared to the lead that is commonly used for traction works. In this case, the operator creates conditions for wheels’ interaction with the terrain without slip/skid at higher inflation pressures in the front tires.