Tractor Speed Research Articles

Auxiliary power supply systems for high speed maglev vehicles with linear synchronous traction motors

Introduction. In linear traction drives of high speed vehicles moving with velocities about 350 - 450 km/h it is expedient to use synchronous motors with stator winding located on track structure and constant magnetic field sources (permanent magnets, superconducting windings or bulk superconductors) located on the vehicle. Such high speed traction system does not require the moving contact for its power supply and it means a considerable advantage of system. Lack of a moving contact on the vehicle involves also the use of contactless system for auxiliary power supply. Purpose. The purpose of the paper is to analyze the versions of contactless auxiliary energy consumers power supply of high speed maglev vehicles with synchronous traction motors. Method. Weight, size and energy parameters of maglev vehicles power supply sources for auxiliary consumers are discussed and their areas of use are analyzed. Results. For contactless power supply of auxiliary energy consumers of maglev vehicles with electrodynamic suspension it is expedient to use linear induction generators and rechargeable batteries. For maglev vehicles with electromagnetic suspension it is expedient to use linear generators, linear transformers and rechargeable batteries. Practical significance. Results may be used for creation of national commercial high speed maglev transport. Conclusion. The choice of combination of power supply sources for auxiliary consumers is determined by vehicle magnetic suspension type. For vehicles with electromagnetic suspension it is expedient to use linear transformers, linear induction generators and rechargeable batteries. For vehicles with electrodynamic suspension use superconducting magnetic systems it is expedient to use linear generators and rechargeable batteries.

Development of tractor operated bund former-cum-packer for increasing resource productivity

In mechanized farm, bund is prepared by a bund former either operated by tractor or animals for irrigation purposes and also to demarcate the fields. Tractor operated bund formers are normally either disc -or mould board or forming board type. If bund is formed with the help of traditional bund former, however, shaping and packing of bunds is done manually using spade and feet. This activity is time consuming and labour intensive. To overcome the drudgery involve in these operations, a tractor operated bund former-cum-packer was designed and developed. An attempt is made for enabling the combined operations of bund forming and packing in single pass that can save fuel, time and other resources further. The bund former-cum-packer consisted of commercially available disc type bund former, rectangular tool bar frame, and packing unit (concentric cylindrical roller, drive shaft, conical discs, compressive shanks etc). The bund formed by bund former-cum-packer was field tested and found neither water seepage nor breakage of bund during flood irrigation. The field capacity with the equipment was 1.4 ha/h at tractor speed of 2.93 km/h in 2nd low gear. The bund former-cum-packer can reduce about 96% dependency on labour requirement for packing the bund. Overall use of the equipment is having potential to increase the resource productivity by 38 %.

IMPROVEMENT OF ROAD-HOLDING ABILITY FOR “BELARUS” TRACTORS

Introduction of new efficient braking systems for energy-packed tractors is of great importance for agricultural production. Foreign tractor manufacturing companies are implementing brake systems and in addition to their main function they fulfil function for holding of the given driving direction. The paper considers achievements in the field of electronic systems for tractor road-holding ability. A diagram on proportion of high-power tractors in total export volume of tractors and machinery manufactured in Belarus in the period of 2007–2010 has been drawn in the paper. The paper also proposes a comparative diagram on tractor speeds of international manufacturers which can serve as indicators of speed and road-holding ability of tractors with special electronic systems and without them. The paper contains an analysis of various braking mechanisms of planetary gears and detailed description of their design. A scheme of a laboratory facility for investigation of planetary gear usage as a breaking mechanism while changing conditions of jamming has been presented in the paper. The paper provides description on graph dependencies of current strength and voltage on as a function of the braking torque which is applied to a planetary gear. Nowadays energy-packed “Belarus”-tractors of Class 5 do not have a separate braking for each of four wheels. Therefore, it is proposed to use planetary gearbox of the rear-axle drive being available in every wheel as the basis of a service brake with the purpose to implement the described design. Using such scheme it is possible to execute an introduction of electronic systems for road-holding ability. A generalized scheme of an electronic system for tractor road-holding ability which can ensure separate breaking of all tractor wheels has been drawn out on the basis of the existing automotive electronic systems .

Conceptual design of sleeve rotor synchronous reluctance motor for traction applications

Synchronous reluctance machines are very appealing for high speed traction motor design due to their robustness, simple structure, absence of magnets, and simple control. The absence of magnets means that synchronous reluctance (SynRel) machines are not susceptible to price variability and sustainability of rare-earth materials. Moreover, there are no concerns about demagnetisation or uncontrolled generation mode. However, the challenge of achieving a good constant power to speed ratio is dependent on the mechanical aspects of the design. Conventional SynRel designs perform poorly compared with the permanent magnet machines due to the presence of bridges and/or centre posts in absence of the magnets to help saturate these regions. In this case, the challenge of rotor mechanical retention is addressed with the help of a sleeve on the rotor to reduce the need for bridges and/or centre posts. Design optimisation including the mechanical aspects of the sleeve is presented in this study. The final design with a sleeve will be shown to be superior to a conventional design in terms of power density, rotor losses, saliency and torque ripple.

MEASURING VIBRATION AT TRACTOR PLATFORM , STEERING WHEEL AND SEAT EFFECTIVE AMPLITUDE TRANSMISSIBILITY FACTOR DURING OPERATION TILLAGE

Field experiment conducted to measure vibrations on three axes longitudinal X, lateral Y and vertical Z on steering wheel, platform tractor and vertical vibration in seat tractor and seat effective amplitude transmissibility (SEAT) factor during operation tillage in silt clay loam soil with depth 18 cm in Baghdad. Split – split plot design under randomized complete block design with three replications least significant design 5 % used. Three factor were used in this experiment included two types of plows included chisel and disc plows which represented main plot, three tires inflation pressure was second factor included 1.1 ,1.8 and 2.7 bar, and three forward speeds of the tillage was third factor included 2.35 , 4.25 and 6.50 km/hr. Results showed disc plow recorded higher vibration values for three axes X,Y and Z on platform, steering wheel and vertical vibration seat tractor. No significant effect between chisel and disc plows in (SEAT) Factor. Tier pressure 2.7 bar recorded higher vibration values in all measurements. Speed tractor 6.50 km/hr recorded higher vibration values in all measurements. Vibration values increasing when increasing tiers inflation pressure and tractor speed. All interaction among treatments significant. Level of vibration in these experiment a cross legislated permissible vibration exposure limits in the world except the vibration transmitted to steering wheel and tractor seat during tillage under 1.1 bar and tractor speed 2.35 km/hr.

ESTIMATING ECONOMICAL COSTS FOR OPERATING AGRICULTURAL MACHINES AND EQUIPMENT DURING PLOWING OPERATIONS

This study was conducted in a field of Al-mahmodia Region in Baghdad , 2014 to estimate the costs of operating Massy Ferguson tractor and tillage equipment in a clay loam soil. Three factors studied through the experiment included:- Three linear speeds for tractor were 2.85, 3.77 and 5.83 km/hr. Two types of plows included moldboard and chisel plow and two systems of plowing included one passage and orthogonal passage for each type of plows. The properties which were studied included fuel consumption, oil costs, maintenance and repair costs, labor costs per hectare. The research was done by applying the factorial experiment according to randomized complete block design with four replications and data were analyzed statistically, mean values of each treatment were compared using LSD at the 0.05 level of confidence to test significance. The results showed the following: Using chisel plow in the orthogonal pass led to increase the rate of fuel consumption, oil costs, maintenance and repair costs and labor costs per hectare, while moldboard plow in one passage achieving decrease the fuel consumption, oil costs, maintenance and repair costs and labor costs . Increasing linear speeds of tractor from 2.85 to 3.77 and 5.83 km/hr caused decreasing in fuel consumption, oil costs, maintenance and repair costs and labor costs per hectare. Linear speed of tractor 5.83 km/hr in one passage indicated significant superiority up on 2.85 and 3.77 km/hr. in achieving decrease the rate of fuel consumption for one hectare.

DETERMINATION OF TRANSMISSION GEAR RATIO IN MECHANICAL PART OF TRACTOR ELECTRO-MECHANICAL TRANSMISSION

A methodology has been developed for selection of gear number and transmission gear ratios in mechanical part of a wheel-type tractor with electro-mechanical transmission containing a propulsion asynchronous electric motor with variablefrequency control. The paper proposes to determine a transmission gear ratio on the basis of the following: provision of wheel torque dependence on tractor speed which is the best one for a traction process and during transfer from one gear to the other; provision of nominal operational mode of the electric motor for all tractor operations where it is working for a long period of time; provision of minimum possible number of gears; complete realization of internal combustion engine power on the tractor wheels at limit operational mode of the electric motor. As a characteristic of the asynchronous electric motor with variable-frequency control contains various portions which can be used either completely or partially due to operating conditions, the gear number is determined in the process of transmission gear ration finding but not prior to this. A wheel torque of the tractor with electro-mechanical transmission can be limited according to the following factors: grip of wheel with supporting surface; maximum power of an internal combustion engine which can be transferred to the wheels and a torque which is developed by a propulsion electric motor. It is not proposed to exceed nominal operational mode of the propulsion electric motor for all the operations of the tractor if it is working for a long period of time because in the case of significant excess of the nominal operational mode of the asynchronous electric motor its rather long operation leads to low efficiency and high losses in power, large heat liberation and consequently requires to develop more complicated system for electric motor cooling. An excess of nominal electric motor torque can be justified for short-term operational modes because in this case there is no need to select more powerful electric motor and create an additional gear in the gear-box.

Rearward Visibility Issues Related to Agricultural Tractors and Self-Propelled Machinery: Contributing Factors, Potential Solutions.

As the size, complexity, and speed of agricultural tractors and self-propelled machinery have increased, so have the visibility-related issues, placing significant importance on the visual skills, alertness, and reactive abilities of the operator. Rearward movement of large agricultural equipment has been identified in the literature as causing both fatalities and injuries to bystanders who were not visible to the operator and damage to both the machine and stationary objects. The addition of monitoring assistance, while not a new concept, has advanced significantly, offering agricultural machinery operators greater options for increasing their awareness of the area surrounding the machine. In this research, we attempt to (1) identify and describe the key contributors to agricultural machinery visibility issues, i.e., operator-related and machine-related factors, and (2) enumerate and evaluate the potential solutions being offered that address these factors. Enhanced operator safety and efficiency should result from a better understanding of the efforts to solve the visibility problems inherent in large tractors and self-propelled agricultural machinery.

Design method and theoretical analysis for wheel-hub driving solar tractor

Burning fossil fuels to produce greenhouse gases, leading to global climate change. The sustainable development requires to design a environmentally benign tractor, which have no or little air pollution during operation. Considering these constraints, Presents a wheel-hub driving solar tractor design method, includes the integral structure design and the main components choose,such as hub moter, battery, gearbox, etc.,and put forward cumulative operation time throughout the day (COTTD) as solar tractor working ability evaluation index. Combined with the local meteorological, predicted the generation capacity of photovoltaic (PV) array in different time of the year, 1.19 kWh/d in winter and 3 kWh/d in summer. Analysis the COTTD relationship with speed of tractor, mass of tractor, slope of road under different work conditions. When the operating speed increases, the trend of COTTD is shortened. Under the same conditions, the COTTD in winter is significantly shorter than the summer. When the speed is 6 km/h on flat road, the COTTD will decrease with the total mass increase. The slope of the road has great influence on COTTD. This research provides valuable technology reference for solar tractor system design and optimize control.

Electric Tractor Motor Drive Control Based on FPGA

Abstract: The electric tractor represents the development trend of sustainable and modern agriculture. With the higher energy efficiency and lower pollution, electric tractor research is significant to modern agriculture. As the electric tractor’s critical technology, motor drive control directly affects the stability of tractor speed and the accuracy of field work. So this paper presented an electric tractor motor drive control system which was suitable for tractor work characteristic based on Brushless DC (BLDC) motor. Double closed loop PID control with outer speed and inner current loop combined with PWM control was implemented as the motor drive control strategy. The motor controller was designed based on FPGA technique, so hardware used NI myRIO as control core which integrated ARM with Xilinx FPGA, and control program used Lab VIEW as development environment. Indoor experiment was conducted to validate the electric tractor motor drive control design.

The Use of the PEMS Equipment for the Assessment of Farm Fieldwork Energy Consumption

<abstract> <b><sc>Abstract. </sc></b>This article presents investigations of fuel consumption and CO₂ emission of a farm tractor operating with a cultivator. The cultivator has been designed to operate at greater speeds of up to 15 km/h. During the tests, the tractor operated with different speeds, which influenced the fuel consumption and the time of operation. An increase in the cruising speed resulted in greater fuel consumption and a reduced time of operation. A fuel consumption curve was determined depending on the tractor speed. At the same time, the authors assessed the quality of the cultivation through soil analysis after the cultivation. The fuel consumption was measured with the carbon balance method – the most accurate method available. Such measurements were performed by the Portable Emission Measurement System (PEMS) equipment. The investigations utilizing the PEMS equipment enable measurements of the exhaust emissions under actual operating conditions, during fieldwork. The methodology used in the research is the most accurate and most reliable one currently available. It takes into account all of the variables of actual operation. This method is a state-of-the-art achievement in exhaust emissions measurement and has great potential. It may be successfully used for research related to assessment of energy consumption of farm tractors depending on the analyzed factors, e.g. type of soil, design of tools, and method of fieldwork. The performed tests allowed formulating conclusions related to the influence of the speed of the farm tractor with the cultivator on fuel consumption and emission of CO₂. From the test, it follows that upon reaching a certain operating speed the increment of the fuel consumption is getting smaller while the time efficiency increases. The authors also observed that the above did not have impact on the quality of the cultivation. The presented results of the investigations and their analysis confirm the usefulness of the applied methodology in the assessment of energy consumption of farm tractors and machines during fieldwork operation.

Determination of the influence of the driving speed on the application parameters of orchard sprayers

Orchard sprayers with air transported fine droplets need an exact adjustment of the airflow and the spray nozzles in order to reduce the drift of pesticides. The adjustment is made on one hand side by the manufacturer and on the other hand side by the farmer in the orchard by choosing the tractor speed, the PTO shaft rotation speed and the pump pressure. For testing two test beds have been in charge in the region of Styria since almost 2 decades. One of them is able to measure the flow field in a vertical plane representing the tree row in a distance of approx. 1.5 m from the middle of the track. The second measures the water distribution in the same vertical plane. Both are stationary so that the influence of the driving speed can hardly be assessed. High driving speeds up to 12 km/h and the increasing height of the orchards impose additional uncertainties. This was the reason for the present research project, which was intended to investigate the influence of the driving speed. A new air flow measurement test bed has been build, which is able to measure the flow field also during tractor movement in the described vertical plane up to 5 m above ground. Four different sprayers have been investigated in an orchard with and without leaves by visual method for four different speeds to determine the optimal application parameters. The same sprayers have been tested with the moveable flow field test bed. Results show a reasonable correlation between the measurements for all investigated speeds. The differences between the sprayers are evident, nevertheless a method has been found to deduce the correlation between the stationary measurement and the optimal parameters for the orchard. So the stationary flow test bed can be directly used to develop sprayers.

The Application of Genetic Algorithm on the Traction Speed Curve Optimizing of the Monorail Train

The Application of Genetic Algorithm on the Traction Speed Curve Optimizing of the Monorail Train

MECHANICAL THINNING OF 'LUCAS' AND 'CONFERENCE' PEAR IMPROVES FRUIT QUALITY

In the absence of any chemicals approved in Europe for flower thinning pears there is a market demand for large particularly ‘Conference’ fruit. The objective of the present study was to improve fruit quality i.e., achieve large fruit sizes. Therefore, 18-year-old ‘Conference’ and ‘Lucas’ pear trees, trained as super spindles, on quince A rootstock with a spacing of 4A—0.4 m were used in Klein-Altendorf near Bonn, Germany; un-thinned adjacent trees served as control. These pear trees with intense flowering were blossom-thinned on 15 April 2009 with rotor speeds of either 300 or 400 rpm both at 5 km h-1 tractor speed. The device with three horizontal rotors and front mounting of the tractor has been developed at the University of Bonn in 2005-2007. By selecting a range of combinations of brushes, rotor speeds (300-450 rpm) and tractor speeds (4-8 km h-1), its vertically operating brushes remove ca. 25-33% of flowers. Due to its use at early developmental stages, i.e., during flowering (between pink bud and petal fall), mechanical thinning on its own can break or prevent alternate/biennial bearing. Mechanical thinning on its own or in combination with either chemical or hand-thinning may improve fruit quality, particularly fruit size (by improving the source sink relationship and enlarging the photo-assimilates partitioned to the remaining fruit, sugar (taste), and sometimes firmness for better storability. June drop was stronger reduced in ‘A. Lucas’ (by -38%) than in ‘Conference’ (by -27% relative to the control). Mechanical blossom thinning reduced the June drop with increasing rotor speed. In ‘A. Lucas’, the natural June drop was as strong as mechanical thinning and resulted in large-sized 80-mm pear fruit in the control; mechanical thinning with 400 rpm further increased fruit mass by 16 g relative to the un-thinned control or 6 g larger than in the thinning with 300 rpm. In ‘Conference’, fruit fell within the next larger fruit size class after the stronger mechanical thinning with 400 rpm at 5 km h-1: the portion of pear fruit in the 75/80 mm size class was 2-fold and in the 80/85 mm size class was 6-fold that in the control. The portion of small fruit such as <60, 60/65 and 65/70 mm was halved relative to the control; the average fruit mass was increased by 40 g without affecting vegetative growth. The risk of both over-sized fruit and over-thinning appeared small, since mechanical thinning reduced the natural June drop without inducing a subsequent fruit drop after thinning. Mechanical thinning was more efficient in ‘Conference’, as intended, despite more intense flowering in ‘A. Lucas’. Overall, the results indicate the potential of mechanical thinning as a substitute or combination partner for chemical fruit thinning if approved such as BA in pear. The device saves labour costs, otherwise required for hand-thinning, in the order of 30-60 h ha-1, equivalent to € 150-300 ha-1, i.e., almost twice as much as the cost of mechanical thinning of ca. 120 € ha-1, based on 20 ha and 10 years depreciation.

A PV Module Surface Dust Removal Device Simulation

In this paper, PV module parameters of dust removal equipment are analyzed; the dust removal device model is established by using solidworks software; the motion simulation of removal process is conducted directly in solidworks motion simulation interface; a comparison of dust removal effects is made between the top-down and the left-to-right dust removal device at the same traction speed and brush dust removal brush rotation speed; a conclusion is drawn that brush traction speed, rotation speed, and helix angle have impact on dust removal effect and the two devices are close to each other in terms of dust removal effect, which provides some theoretical evidence for further design.

Studying Characteristics of Traction Induction Motors for Variable-Speed Mine Electric Locomotive

The analysis of torque-speed characteristics of induction motors has been carried out in order to choose the base design for variable speed traction electric drives of underground mine electric locomotives. For constant dimensions of active part of series-produced electric motors the influence of the diverse conductivity’s materials for manufacturing the squirrel-cage rotor on speed-torque and speed-current characteristics. The designs are compared according to speed-up dynamics, power indexes and key design features of the studied electric motors.

Development of stability indicators for dynamic Phase I overturn of conventional farm tractors with front axle pivot

Tractor overturns are serious potential hazards for operators. While rollover protective structures (ROPS) protect operators passively, greater protection can be achieved through theoretical prediction of a potential overturn. Given effective warning, an operator can act to correct a tractor's motion when a tyre is about to lose contact with the ground. Such a loss of contact is associated with the initiation of a Phase I tractor overturn. However, it remains unclear how the initiation of tractor overturn is influenced by certain factors. Furthermore, the current mathematical models for tractors should be further extended for general utilisation. This study was conducted to develop stability indicators based on a more general model for dynamic Phase I tractor overturn. We considered practical tractor configurations and motion characteristics in a three-dimensional (3D) reference frame in formulating the mathematical model. Tractor stability indicators for overturn and sideslip were derived from force calculations. A parametric study was conducted using an example tractor. The tractor speed and slope angle were found to affect the overturning stability significantly. The coefficient of maximum static friction was found to be the main factor contributing to tractor sideslip. Critical tractor speeds for various ground conditions were identified by considering the zero values of the tractor stability indicators. The critical tractor speed was determined as a function of the maximum static friction and the slope angle. By providing a display device based on ergonomics principles, the results of this study can be further implemented in the form of guidance to operators.

Hybrid Control for Bidirectional Z-Source Inverter for Locomotives

Electric traction uses three phase locomotives in main line services. Three phase locomotives consist of voltage source inverters for driving the traction motors. This paper proposes a hybrid algorithm for bidirectional Z-source inverters in accelerating region of operation of locomotives. The speed control method adopted is same as that in the existing three phase locomotives which is variable voltage variable frequency. Bidirectional Z-source inverter is designed for getting the same output power as in voltage source inverter fed locomotives. Simulation is done in all regions of traction speed curve, namely, acceleration, free running, and braking by regeneration. The voltage stress across the devices and modulation index are considered while analyzing the proposed control algorithm. It is found that the modulation index remains at a high value over the entire range of frequencies. Due to the higher value of modulation index the harmonics in the inverter output voltage is reduced. Also the voltage stress across devices is limited to a value below the device rating used in the present three phase locomotives. A small scale prototype of the bi-directional Z-source inverter fed drive is developed in the laboratory and the hybrid control was verified in the control topology.

Simulation of gear change in transmissions of agricultural tractors

The paper deals with the gearshift modeling process in transmissions of agricultural tractors and the method of sectionally continuously variation of tractor speed, based on the rational choice of using only a small range of adjustment characteristics of the engine where the power does not drop below minimal and fuel economy is maintained.

SELECTIVE MECHANICAL THINNING FOR CROP LOAD MANAGEMENT (CLM) OF FRUIT TREES

Re-registration of all agricultural chemicals under Annex 1 of EU 91/414 reduced the number of compounds available for thinning. Additionally, supermarkets in the UK and Germany require growing certificates, which either limit the amount of chemicals used to a maximum number or exclude particular practises or chemicals. Mechanical thinning is an innovative approach for thinning fruit crops trained to any kind of spindle trees, irrespective of species, cultivar, temperature and tree age and is an alternative to or compliments chemical thinning. Four concepts of its implementation are presented here: a) sole use of mechanical thinning to overcome alternate bearing, b) combination of mechanical thinning with chemical (and hand-thinning) in IFP, c) combination with lime sulphur where approved for organic fruit farming, and d) combination of mechanical thinning with hand–thinning where no chemicals are approved. The device with three horizontal rotors and front mounting on the tractor has been developed at the University of Bonn in 2005-2010. Using a range of combinations of brushes, rotor speeds (320-420 rpm) and tractor speeds (5 to 7.5 km/h), its vertically operating brushes remove ca. 25-33% of flowers. Because of its use at early developmental stages, i.e., during flowering (between pink bud and petal fall), mechanical thinning on its own can break or prevent alternate/ biennial bearing. Mechanical thinning on its own or in combination with either chemical or hand-thinning improved fruit quality, particularly fruit size (by improving the source sink relationship and enlarging the photo-assimilates partitioned to the remaining fruit) and colouration (by allowing more light access to the fruit and removal of shade fruits from the inner canopy), sugar (taste), and sometimes firmness for better storability. The device saves labour costs, otherwise required for hand-thinning, in the order of 15-30 hours per hectare, equivalent to € 100-150/ha, i.e., in the same order as the cost of mechanical thinning of ca. 120 €/ha, based on 20 ha and 10 years depreciation.