The Experts below are selected from a list of 29676 Experts worldwide ranked by ideXlab platform
Chun-taek Rim - One of the best experts on this subject based on the ideXlab platform.
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uniform power i type inductive power transfer system with dq power supply rails for on line electric vehicles
IEEE Transactions on Power Electronics, 2015Co-Authors: Changbyung Park, Gyuhyeong Cho, Sungwoo Lee, Seog Y. Jeong, Chun-taek RimAbstract:A narrow-width power-invariant inductive power transfer system (IPTS) along the Driving Direction is newly proposed in this paper. The conventional I-type power supply rail for on-line electric vehicles (OLEVs) has a very narrow power supply rail with 10-cm width and exposes pedestrians to a very low electromagnetic field due to its alternatively arranged magnetic poles along the Driving Direction of electric vehicles; however, it has a major drawback: Sinusoidal variation of the induced pick-up voltage depending on pick-up positions on the power supply rail along Driving Direction. To overcome this disadvantage, a dq -power supply rail fed by two high-frequency ac currents of the d -phase and q -phase is introduced in this paper. The d -phase and q -phase magnetic poles are alternatively arranged in a line; hence, the induced voltage of a pickup becomes spatially uniform. The power invariant characteristic of the proposed IPTS for OLEV has been verified by analysis, simulations, and experiments. A practical winding method is suggested as well.
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uniform power i type inductive power transfer system with dq power supply rails for on line electric vehicles
IEEE Transactions on Power Electronics, 2015Co-Authors: Changbyung Park, Gyuhyeong Cho, Sungwoo Lee, Seog Y. Jeong, Chun-taek RimAbstract:A narrow-width power-invariant inductive power transfer system (IPTS) along the Driving Direction is newly proposed in this paper. The conventional I-type power supply rail for on-line electric vehicles (OLEVs) has a very narrow power supply rail with 10-cm width and exposes pedestrians to a very low electromagnetic field due to its alternatively arranged magnetic poles along the Driving Direction of electric vehicles; however, it has a major drawback: Sinusoidal variation of the induced pick-up voltage depending on pick-up positions on the power supply rail along Driving Direction. To overcome this disadvantage, a dq -power supply rail fed by two high-frequency ac currents of the d -phase and q -phase is introduced in this paper. The d -phase and q -phase magnetic poles are alternatively arranged in a line; hence, the induced voltage of a pickup becomes spatially uniform. The power invariant characteristic of the proposed IPTS for OLEV has been verified by analysis, simulations, and experiments. A practical winding method is suggested as well.
Changbyung Park - One of the best experts on this subject based on the ideXlab platform.
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uniform power i type inductive power transfer system with dq power supply rails for on line electric vehicles
IEEE Transactions on Power Electronics, 2015Co-Authors: Changbyung Park, Gyuhyeong Cho, Sungwoo Lee, Seog Y. Jeong, Chun-taek RimAbstract:A narrow-width power-invariant inductive power transfer system (IPTS) along the Driving Direction is newly proposed in this paper. The conventional I-type power supply rail for on-line electric vehicles (OLEVs) has a very narrow power supply rail with 10-cm width and exposes pedestrians to a very low electromagnetic field due to its alternatively arranged magnetic poles along the Driving Direction of electric vehicles; however, it has a major drawback: Sinusoidal variation of the induced pick-up voltage depending on pick-up positions on the power supply rail along Driving Direction. To overcome this disadvantage, a dq -power supply rail fed by two high-frequency ac currents of the d -phase and q -phase is introduced in this paper. The d -phase and q -phase magnetic poles are alternatively arranged in a line; hence, the induced voltage of a pickup becomes spatially uniform. The power invariant characteristic of the proposed IPTS for OLEV has been verified by analysis, simulations, and experiments. A practical winding method is suggested as well.
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uniform power i type inductive power transfer system with dq power supply rails for on line electric vehicles
IEEE Transactions on Power Electronics, 2015Co-Authors: Changbyung Park, Gyuhyeong Cho, Sungwoo Lee, Seog Y. Jeong, Chun-taek RimAbstract:A narrow-width power-invariant inductive power transfer system (IPTS) along the Driving Direction is newly proposed in this paper. The conventional I-type power supply rail for on-line electric vehicles (OLEVs) has a very narrow power supply rail with 10-cm width and exposes pedestrians to a very low electromagnetic field due to its alternatively arranged magnetic poles along the Driving Direction of electric vehicles; however, it has a major drawback: Sinusoidal variation of the induced pick-up voltage depending on pick-up positions on the power supply rail along Driving Direction. To overcome this disadvantage, a dq -power supply rail fed by two high-frequency ac currents of the d -phase and q -phase is introduced in this paper. The d -phase and q -phase magnetic poles are alternatively arranged in a line; hence, the induced voltage of a pickup becomes spatially uniform. The power invariant characteristic of the proposed IPTS for OLEV has been verified by analysis, simulations, and experiments. A practical winding method is suggested as well.
Thomas Keller - One of the best experts on this subject based on the ideXlab platform.
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rubber track systems for conventional tractors effects on soil compaction and traction
Soil & Tillage Research, 2011Co-Authors: Johan Arvidsson, Thomas Keller, Hugo Westlin, Mikael GilbertssonAbstract:Abstract Traditionally, tractors have been built either for tracks or wheels, with tracks mainly on heavy tractors with high power. Today, it is possible to retrofit four separate track units on a conventional agricultural tractor, creating interesting possibilities for agriculture. The objective of the present study was to compare soil compaction and traction for tracks, single and dual wheels mounted on the same tractor type. Measurements were made on two clay soils (Eutric Cambisols) in Sweden in 2009, using an 85 kW tractor with a total weight of 7700 kg. The rubber track system consisted of four tracks mounted on the conventional wheel axles of the tractor. The measured stresses were similar for the tracks and dual wheels at all depths studied (15, 30 and 50 cm), but were considerably higher for the single wheels at all depths. Simulations of soil stresses correlated closely to measured values for the tracks and the dual wheels, but underestimated soil stresses in the topsoil compared to measured values for the single wheel. Bulk density and penetration resistance were consistently highest and saturated hydraulic conductivity lowest after wheeling with single wheels, while there were no statistically significant differences between tracks and dual wheels. With single wheels and the tractor loaded, saturated hydraulic conductivity decreased to 0.01 m h −1 from 0.13 m h −1 in the control, while bulk density increased from 1.24 to 1.36 Mg m −3 . The stress distribution in the Driving Direction was relatively even along the front and rear tracks, which is an advantage compared with a long single track, which often has an uneven longitudinal stress distribution. Slip was significantly higher for the dual and single wheels compared with tracks. To utilise the large contact area of the tracks, the tractor should have a low weight in relation to the engine power.
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modelling effects of tyre inflation pressure on the stress distribution near the soil tyre interface
Biosystems Engineering, 2008Co-Authors: Per Schjonning, Mathieu Lamandé, Johan Arvidsson, Frede Aakmann Togersen, Thomas KellerAbstract:Several investigations have shown that the distribution of vertical stress in soil just below a loaded tyre is not uniform. The stress distribution and the size and form of the tyre–soil interface are decisive for the stress propagation in the soil profile. We measured the distribution of vertical stress in the contact area for two radial-ply agricultural trailer tyres (650/65R30.5 and 800/50R34) loaded with ∼60 kN. The study took place on a sandy soil at a water content slightly less than field capacity. We tested the effect of three different inflation pressures (50, 100 and 240 kPa) in a randomised block design with three replicates. The vertical stress was measured with load cells located in 0.1 m soil depth. The vertical stress data were used also for identifying the soil area in contact with the tyre, i.e. the tyre footprint. A model (named FRIDA) is proposed that describes the tyre footprint by a super ellipse and the stress distribution by a combined exponential (perpendicular to the Driving Direction) and power-law (along the Driving Direction) function. The contact area doubled when the inflation pressure was reduced from 240 to 50 kPa. For both tyres, the measured peak stress increased significantly with tyre inflation pressure and was generally about 90 kPa higher than tyre inflation pressure. The model-fitted maximum stress was about 50 kPa higher than the inflation pressure. The 650/65R30.5 tyre displayed a longer footprint and a more uniform stress distribution in the Driving Direction and performed better at non-recommended inflation pressures than the 800/50R34. At the recommended inflation pressure, both tyres displayed a stress distribution across the width of the wheel that could be evaluated as optimal with regard to a minimised topsoil compaction. The suggested model seems very well suited for describing real stress distributions at the soil–tyre interface, but should be validated also with other tyres, wheel loads, and soil conditions. It has the potential to improve soil compaction models considerably and also for use to evaluate important features of tyres with scope to improve future designs.
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soil stress as affected by wheel load and tyre inflation pressure
Soil & Tillage Research, 2007Co-Authors: Thomas Keller, Johan ArvidssonAbstract:Abstract The relative importance of wheel load and tyre inflation pressure on topsoil and subsoil stresses has long been disputed in soil compaction research. The objectives of the experiment presented here were to (1) measure maximum soil stresses and stress distribution in the topsoil for different wheel loads at the same recommended tyre inflation pressure; (2) measure soil stresses at different inflation pressures for the given wheel loads; and (3) measure subsoil stresses and compare measured and simulated values. Measurements were made with the wheel loads 11, 15 and 33 kN at inflation pressures of 70, 100 and 150 kPa. Topsoil stresses were measured at 10 cm depth with five stress sensors installed in disturbed soil, perpendicular to Driving Direction. Contact area was measured on a hard surface. Subsoil stresses were measured at 30, 50 and 70 cm depth with sensors installed in undisturbed soil. The mean ground contact pressure could be approximated by the tyre inflation pressure (only) when the recommended inflation pressure was used. The maximum stress at 10 cm depth was considerably higher than the inflation pressure (39% on average) and also increased with increasing wheel load. While tyre inflation pressure had a large influence on soil stresses measured at 10 cm depth, it had very little influence in the subsoil (30 cm and deeper). In contrast, wheel load had a very large influence on subsoil stresses. Measured and simulated values agreed reasonably well in terms of relative differences between treatments, but the effect of inflation pressure on subsoil stresses was overestimated in the simulations. To reduce soil stresses exerted by tyres in agriculture, the results show the need to further study the distribution of stresses under tyres. For calculation of subsoil stresses, further validations of commonly used models for stress propagation are needed.
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technical solutions to reduce the risk of subsoil compaction effects of dual wheels tandem wheels and tyre inflation pressure on stress propagation in soil
Soil & Tillage Research, 2004Co-Authors: Thomas Keller, Johan ArvidssonAbstract:Abstract The use of heavy machinery is increasing in agriculture, which induces increased risks of subsoil compaction. Hence, there is a need for technical solutions that reduce the compaction risk at high total machine loads. Three field experiments were performed in order to study the effects of dual wheels, tandem wheels and tyre inflation pressure on stress propagation in soil. Vertical soil stress was measured at three different depths by installing probes into the soil horizontally from a dug pit. In one experiment, also the stress distribution below the tyre was measured. Beneath the dual wheels, vertical stresses at 0.15 and 0.3 m depth were lower between the two wheels than under the centre of each wheel, despite the gap between the wheels being small (0.1 m). At 0.5 m depth, vertical stress beneath the wheels was the same as between the two wheels. The stress interaction from the two wheels was weak, even in the subsoil. Accordingly, measured stresses at 0.3, 0.5 and 0.7 m depth were highest under the centre of each axle centre line of tandem wheels, and much lower between the axles. For a wheel load of 86 kN, tyre inflation pressure significantly affected stress at 0.3 m depth, but not at greater depths. Stress directly below the tyre, measured at 0.1 m depth, was unevenly distributed, both in Driving Direction and perpendicular to Driving Direction, and maximum stress was considerably higher than tyre inflation pressure. Calculations of vertical stress based on Boussinesq's equation for elastic materials agreed well with measurements. A parabolic or linear contact stress distribution (stress declines from the centre to the edge of the contact area) was a better approximation of the contact stress than a uniform stress distribution. The results demonstrate that stress in the soil at different depths is a function of the stress on the surface and the contact area, which in turn are functions of wheel load, wheel arrangement, tyre inflation pressure, contact stress distribution and soil conditions. Soil stress and soil compaction are a function of neither axle load nor total vehicle load. This is of great importance for practical purposes. Reducing wheel load, e.g. by using dual or tandem wheels, also allows tyre inflation pressure to be reduced. This reduces the risk of subsoil compaction.
Johan Arvidsson - One of the best experts on this subject based on the ideXlab platform.
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rubber track systems for conventional tractors effects on soil compaction and traction
Soil & Tillage Research, 2011Co-Authors: Johan Arvidsson, Thomas Keller, Hugo Westlin, Mikael GilbertssonAbstract:Abstract Traditionally, tractors have been built either for tracks or wheels, with tracks mainly on heavy tractors with high power. Today, it is possible to retrofit four separate track units on a conventional agricultural tractor, creating interesting possibilities for agriculture. The objective of the present study was to compare soil compaction and traction for tracks, single and dual wheels mounted on the same tractor type. Measurements were made on two clay soils (Eutric Cambisols) in Sweden in 2009, using an 85 kW tractor with a total weight of 7700 kg. The rubber track system consisted of four tracks mounted on the conventional wheel axles of the tractor. The measured stresses were similar for the tracks and dual wheels at all depths studied (15, 30 and 50 cm), but were considerably higher for the single wheels at all depths. Simulations of soil stresses correlated closely to measured values for the tracks and the dual wheels, but underestimated soil stresses in the topsoil compared to measured values for the single wheel. Bulk density and penetration resistance were consistently highest and saturated hydraulic conductivity lowest after wheeling with single wheels, while there were no statistically significant differences between tracks and dual wheels. With single wheels and the tractor loaded, saturated hydraulic conductivity decreased to 0.01 m h −1 from 0.13 m h −1 in the control, while bulk density increased from 1.24 to 1.36 Mg m −3 . The stress distribution in the Driving Direction was relatively even along the front and rear tracks, which is an advantage compared with a long single track, which often has an uneven longitudinal stress distribution. Slip was significantly higher for the dual and single wheels compared with tracks. To utilise the large contact area of the tracks, the tractor should have a low weight in relation to the engine power.
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modelling effects of tyre inflation pressure on the stress distribution near the soil tyre interface
Biosystems Engineering, 2008Co-Authors: Per Schjonning, Mathieu Lamandé, Johan Arvidsson, Frede Aakmann Togersen, Thomas KellerAbstract:Several investigations have shown that the distribution of vertical stress in soil just below a loaded tyre is not uniform. The stress distribution and the size and form of the tyre–soil interface are decisive for the stress propagation in the soil profile. We measured the distribution of vertical stress in the contact area for two radial-ply agricultural trailer tyres (650/65R30.5 and 800/50R34) loaded with ∼60 kN. The study took place on a sandy soil at a water content slightly less than field capacity. We tested the effect of three different inflation pressures (50, 100 and 240 kPa) in a randomised block design with three replicates. The vertical stress was measured with load cells located in 0.1 m soil depth. The vertical stress data were used also for identifying the soil area in contact with the tyre, i.e. the tyre footprint. A model (named FRIDA) is proposed that describes the tyre footprint by a super ellipse and the stress distribution by a combined exponential (perpendicular to the Driving Direction) and power-law (along the Driving Direction) function. The contact area doubled when the inflation pressure was reduced from 240 to 50 kPa. For both tyres, the measured peak stress increased significantly with tyre inflation pressure and was generally about 90 kPa higher than tyre inflation pressure. The model-fitted maximum stress was about 50 kPa higher than the inflation pressure. The 650/65R30.5 tyre displayed a longer footprint and a more uniform stress distribution in the Driving Direction and performed better at non-recommended inflation pressures than the 800/50R34. At the recommended inflation pressure, both tyres displayed a stress distribution across the width of the wheel that could be evaluated as optimal with regard to a minimised topsoil compaction. The suggested model seems very well suited for describing real stress distributions at the soil–tyre interface, but should be validated also with other tyres, wheel loads, and soil conditions. It has the potential to improve soil compaction models considerably and also for use to evaluate important features of tyres with scope to improve future designs.
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soil stress as affected by wheel load and tyre inflation pressure
Soil & Tillage Research, 2007Co-Authors: Thomas Keller, Johan ArvidssonAbstract:Abstract The relative importance of wheel load and tyre inflation pressure on topsoil and subsoil stresses has long been disputed in soil compaction research. The objectives of the experiment presented here were to (1) measure maximum soil stresses and stress distribution in the topsoil for different wheel loads at the same recommended tyre inflation pressure; (2) measure soil stresses at different inflation pressures for the given wheel loads; and (3) measure subsoil stresses and compare measured and simulated values. Measurements were made with the wheel loads 11, 15 and 33 kN at inflation pressures of 70, 100 and 150 kPa. Topsoil stresses were measured at 10 cm depth with five stress sensors installed in disturbed soil, perpendicular to Driving Direction. Contact area was measured on a hard surface. Subsoil stresses were measured at 30, 50 and 70 cm depth with sensors installed in undisturbed soil. The mean ground contact pressure could be approximated by the tyre inflation pressure (only) when the recommended inflation pressure was used. The maximum stress at 10 cm depth was considerably higher than the inflation pressure (39% on average) and also increased with increasing wheel load. While tyre inflation pressure had a large influence on soil stresses measured at 10 cm depth, it had very little influence in the subsoil (30 cm and deeper). In contrast, wheel load had a very large influence on subsoil stresses. Measured and simulated values agreed reasonably well in terms of relative differences between treatments, but the effect of inflation pressure on subsoil stresses was overestimated in the simulations. To reduce soil stresses exerted by tyres in agriculture, the results show the need to further study the distribution of stresses under tyres. For calculation of subsoil stresses, further validations of commonly used models for stress propagation are needed.
-
technical solutions to reduce the risk of subsoil compaction effects of dual wheels tandem wheels and tyre inflation pressure on stress propagation in soil
Soil & Tillage Research, 2004Co-Authors: Thomas Keller, Johan ArvidssonAbstract:Abstract The use of heavy machinery is increasing in agriculture, which induces increased risks of subsoil compaction. Hence, there is a need for technical solutions that reduce the compaction risk at high total machine loads. Three field experiments were performed in order to study the effects of dual wheels, tandem wheels and tyre inflation pressure on stress propagation in soil. Vertical soil stress was measured at three different depths by installing probes into the soil horizontally from a dug pit. In one experiment, also the stress distribution below the tyre was measured. Beneath the dual wheels, vertical stresses at 0.15 and 0.3 m depth were lower between the two wheels than under the centre of each wheel, despite the gap between the wheels being small (0.1 m). At 0.5 m depth, vertical stress beneath the wheels was the same as between the two wheels. The stress interaction from the two wheels was weak, even in the subsoil. Accordingly, measured stresses at 0.3, 0.5 and 0.7 m depth were highest under the centre of each axle centre line of tandem wheels, and much lower between the axles. For a wheel load of 86 kN, tyre inflation pressure significantly affected stress at 0.3 m depth, but not at greater depths. Stress directly below the tyre, measured at 0.1 m depth, was unevenly distributed, both in Driving Direction and perpendicular to Driving Direction, and maximum stress was considerably higher than tyre inflation pressure. Calculations of vertical stress based on Boussinesq's equation for elastic materials agreed well with measurements. A parabolic or linear contact stress distribution (stress declines from the centre to the edge of the contact area) was a better approximation of the contact stress than a uniform stress distribution. The results demonstrate that stress in the soil at different depths is a function of the stress on the surface and the contact area, which in turn are functions of wheel load, wheel arrangement, tyre inflation pressure, contact stress distribution and soil conditions. Soil stress and soil compaction are a function of neither axle load nor total vehicle load. This is of great importance for practical purposes. Reducing wheel load, e.g. by using dual or tandem wheels, also allows tyre inflation pressure to be reduced. This reduces the risk of subsoil compaction.
Seog Y. Jeong - One of the best experts on this subject based on the ideXlab platform.
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uniform power i type inductive power transfer system with dq power supply rails for on line electric vehicles
IEEE Transactions on Power Electronics, 2015Co-Authors: Changbyung Park, Gyuhyeong Cho, Sungwoo Lee, Seog Y. Jeong, Chun-taek RimAbstract:A narrow-width power-invariant inductive power transfer system (IPTS) along the Driving Direction is newly proposed in this paper. The conventional I-type power supply rail for on-line electric vehicles (OLEVs) has a very narrow power supply rail with 10-cm width and exposes pedestrians to a very low electromagnetic field due to its alternatively arranged magnetic poles along the Driving Direction of electric vehicles; however, it has a major drawback: Sinusoidal variation of the induced pick-up voltage depending on pick-up positions on the power supply rail along Driving Direction. To overcome this disadvantage, a dq -power supply rail fed by two high-frequency ac currents of the d -phase and q -phase is introduced in this paper. The d -phase and q -phase magnetic poles are alternatively arranged in a line; hence, the induced voltage of a pickup becomes spatially uniform. The power invariant characteristic of the proposed IPTS for OLEV has been verified by analysis, simulations, and experiments. A practical winding method is suggested as well.
-
uniform power i type inductive power transfer system with dq power supply rails for on line electric vehicles
IEEE Transactions on Power Electronics, 2015Co-Authors: Changbyung Park, Gyuhyeong Cho, Sungwoo Lee, Seog Y. Jeong, Chun-taek RimAbstract:A narrow-width power-invariant inductive power transfer system (IPTS) along the Driving Direction is newly proposed in this paper. The conventional I-type power supply rail for on-line electric vehicles (OLEVs) has a very narrow power supply rail with 10-cm width and exposes pedestrians to a very low electromagnetic field due to its alternatively arranged magnetic poles along the Driving Direction of electric vehicles; however, it has a major drawback: Sinusoidal variation of the induced pick-up voltage depending on pick-up positions on the power supply rail along Driving Direction. To overcome this disadvantage, a dq -power supply rail fed by two high-frequency ac currents of the d -phase and q -phase is introduced in this paper. The d -phase and q -phase magnetic poles are alternatively arranged in a line; hence, the induced voltage of a pickup becomes spatially uniform. The power invariant characteristic of the proposed IPTS for OLEV has been verified by analysis, simulations, and experiments. A practical winding method is suggested as well.
