Tools and methods to develop and validate soil-wheel interaction model and knowledge

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1 Tools and methods to develop and validate soil-wheel interaction model and knowledge P. Heritier a *, D. Miclet a, E. Piron a, M. Chanet a, R. Lenain a a Irstea, AgroTechnoPôle, Centre de Clermont-Ferrand - Montoldre 1st AXEMA-EurAgEng Conference Feb 25,

2 Introduction Losses = f (tyre, soil): GP NP Tire parameters - structure, - Vertical load, - Inflation pressure, - Tyre diameter, width. Soil parameters - texture, - Temperature, - Humidity, - Cone Index. Losses On soft surface (agricultural soil) On hard surface (asphalt) Impact Soil Tyre - Tyre deformation. Impact Tyre Soil - Rutting, - Soil compaction. - Rolling Resistance - Slippage - Tire efficiency - Rolling Resistance - Tire efficiency 2

3 Agenda I ) Tyre efficiency measurement II ) Tyre deformation measurement and tyre-sensor III ) Tyre Soil compaction comparison using different tools and method Conclusion 3

4 I ) Tyre efficiency measurement Issues: - Input Power =? Efficiency issue Output Power - Applied weight influence - Tyre type, inflation, etc, influences - Soil type, humidity, hardness, influence The Single-wheel tester 4

ω i - Gross Power Electrohydraulic control unit

avoided) Deformable parallelogram Every tyre

5 I ) Tyre efficiency measurement The Single-wheel tester Net traction (NT) : - Horizontal forces only - Max. = 15000daN Torque «(T) : Max. = 2000daN. Allows calculation: NP i = NTi. Vr i - Net Power GPi = Ti. ω i - Gross Power Electrohydraulic control unit Vertical known, constant weight (weight report avoided) Deformable parallelogram Every tyre (depending sizes) Wheel angular velocity (ω) 3 points linkage Real speed (Vr): - dgps - Centimeter resolution Static load support 5

6 I ) Tyre efficiency measurement The Single-wheel tester Electrohydraulic control unit 2 different control mode: - apply a Constant Torque / Measure NT, Vr and ω - apply a Constant NT / Measure T, Vr and ω (can be defined using CT = NT : Coef. Traction) W NT =?? Vr =?? T = Cte ω =?? 6

7 I ) Tyre efficiency measurement The Single-wheel tester Result examples for 4 increasing CT (0 / 0,2 /,3 / 0,4) NT maintained constant during each CT level CT - Vr - Torque - Vth NP and GP Which efficiency? 7

I ) Tyre efficiency measurement The Single-wheel tester / Performance indices ENTAM actual work: * Pull loss index (PLI): Traction case Pull_Loss_Index PLI = «smaller is better» GP NP NP The same

8 I ) Tyre efficiency measurement The Single-wheel tester / Performance indices ENTAM actual work: * Pull loss index (PLI): Traction case Pull_Loss_Index PLI = «smaller is better» GP NP NP The same than efficiency, but with the relative value = used value NP * Carry loss index (CLI): Self-propelling case: NT = 0. Carry_Loss_Index CLI = «smaller is better» T ω W V Input 150 Case of PLI = 50%: Transmitted Slippage = f (CT) 50 Lost Output 100 Main losses: - Rolling (soil and tyre deformation) - Slippage 8

9 I ) Tyre efficiency measurement 9

II ) Tyre deformation / «Sensitive tyre»

can slid on rim) Good accuracy (around 1 mm), High

10 II ) Tyre deformation / «Sensitive tyre» Measurement devices embedded: Potentiometric linear displacement sensor Measurement point Strengths / Weaknesses: Technic with contact (tyre can slid on rim) Good accuracy (around 1 mm), High acquisition frequency (100Hz and more) Gives X, Y et Z deformations. 10

II ) Tyre deformation / «Sensitive tyre» Deformation during rolling at constant speed on flat ground Rolling direction Zmin Contact patch Some observations : No forces on lateral axe = No

11 II ) Tyre deformation / «Sensitive tyre» Deformation during rolling at constant speed on flat ground Rolling direction Zmin Contact patch Some observations : No forces on lateral axe = No deformation on Y axis Z axis : peak corresponding to the tire max. deflection = increase of tyre radius outside the surface in contact with the ground X axis : deradialization deformation 11

12 II ) Tyre deformation / «Sensitive tyre» 1000 Deformation during rolling at constant speed on flat ground Y position (mm) Just the Torque consequency X position (mm) Y position (mm) Y position (mm) X position (mm) X position (mm) 12

13 II ) Tyre deformation / «Sensitive tyre» Radial deformation Without Torque With Torque dx (mm)

14 II ) Tyre deformation / «Sensitive tyre» Load estimation from radial deformations (ActisurTT project) 14

15 III ) Soil compaction measurement 3D laser Scanner FARO Focus 3D X130 R=130m Resol. = 1mm 15

16 III ) Soil compaction measurement 3D laser Scanner Results examples 2700daN Identical load 2700daN Transversal position (cm) Transversal position (cm) Depth (cm) Natural soil level 16

17 III ) Soil compaction measurement 3D laser Scanner Results examples Narrow tire 3D view Low pressure tire Depths distribution Thread background frequency Thread Frequency Thread background thread Non compacted soil Non compacted soil Sinkage > 10cm Depth (cm) Sinkage = 4cm Depth (cm) 17

III ) Soil compaction measurement Automatic penetrometer Many measurements each 2cm local measurements, with high accuracy and high resolution

18 III ) Soil compaction measurement Automatic penetrometer Many measurements each 2cm local measurements, with high accuracy and high resolution recording force during the lowering of the rod section that can be achieved is 120 cm 115 cm (width height) Local pressure measurement out / in footprint 18

19 III ) Soil compaction measurement Automatic penetrometer: Example of results 2700daN Identical load 2700daN Depth (cm) Depth (cm) Deformation Compaction Transversal position (cm) Transversal position (cm) Depth (cm) Pressure (bar) Natural soil level 19

20 III ) Soil compaction measurement Scattering device measurement : OCPS Sensor 3 points linkage Support 3 points linkage Support Rotation axis Depth control wheel 30cm blade 40cm blade 10cm 40cm 20cm 20

21 III ) Soil compaction Example of use for track vs tyre: Low pressure tyres Both technologies used to reduce impact on agricultural soils Rubber tracks Highlighted commercial advantages: - low pressure operation - greatly increases the footprint Highlighted commercial advantages: - easy to install, - greatly limits stress on the soil, Front axle equipment: 3 tested modalities: - Tyres: inflation pressure influence, - Tracks vs tire compaction with same loading. 22

22 III ) Soil compaction Example of use for track vs tyre: 1st step: Use of different harvester equipment on an agricultural field Harvester trajectories all record using centrimetric GPS 2nd step: Measure the hardness to «cut the soil» Using OCPS device 3rd step: Data treatment 4th step: Results Hardness Mean Value for all repetitions = One steel blade Displacement axis 23

23 III ) Soil compaction measurement Scattering device measurement: OCPS Field hardness map Measured hardness (dan) Hardness (dan) 24

24 Conclusion - Set of complementary tools around Tyre / Soil - Usefull to: - Compare technologies (tyres) - Know more about phenomena - Validate models - Available at Irstea AgroTechnoPôle Montoldre for research collaborations 25

Axema-EurAgEng Conference 2017 February 25

Axema-EurAgEng Conference 2017 February 25 A VIRTUAL SPREADER TO OVERCOME EXPERIMENTAL LIMITS: EXAMPLE OF USE TO DEEPEN THE MEANING OF THE TRANSVERSE COEFFICIENT OF VARIATION S Villette (1*), E Piron (2),