Draft Prediction of Combination Tillage Implements

8/13/2019 Draft Prediction of Combination Tillage Implements

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DRAFTPREDICTIONOFCOMBINATIONTILLAGEIMPLEMENTS

Presented by: Shweta Singh

13AG61R07

Agricultural and food

engineering department

Hifjur Raheman

Rohit K. Sahu

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OVERVIEW

Introduction

Objective

Materials and method

Experimental procedure Results and discussion

Conclusion

References

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INTRODUCTION

Combination tillage: multiple tillage operations in a single

pass.

Reduces number of field passes resulting in reduction of

labor, fuel cost and time.

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Combination

tillageimplements

Active-Passive

Passive-Passive

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5

Working pattern of a combined tillage machinery


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OBJECTIVE

To develop draft prediction equation for passive-passive

combination tillage implement.

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MATERIALSANDMETHODS

Based on the theoretical approach for activepassive

combination tillage implements as proposed by Bernacki et

al. (1972), this study on draft prediction of passivepassive

combination tillage implements was carried out.

Rc = Rfc + Rrc

where,

Rc = specific draft of combination tillage implement

Rfc = specific draft of front passive tillage implement

Rrc = specific draft of rear passive tillage implement

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CONTD..

Specific draft can also be expressed as:

Rc = Rf + Rr

where,

Rf = specific draft of front passive set operatingindividually( Rf = Rfc, because draft encountered by frontimplement will same in both cases)

Rr = specific draft of rear passive set operating individually

= draft utilization factor8


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CONTD..

=Rrc

=Drc

Ar=Arc

where,

Arc and Ar = cross sectional area for combination tillage

and individual tillage

=

So,

Dc = Df + Dr

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DRAFTOFINDIVIDUALTILLAGETOOL

=

where

Dp = draft of any prototype/scale-model implement

Dr = draft of the reference tillage tool

w= wet bulk density of soil

ws= wet bulk density of reference soil (1.28 g/cm)

CI = cone index of soil

CIs = cone index of the reference soil condition(472kPa)

Wp = prototype/scale model implement width

Wt = reference tillage tool width

and a, b and c are regression coefficients for soil. 10


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DRAFT OF REFERENCE TILLAGE TOOL

The draft of the reference tillage tools in the reference soil

condition at different speeds and depths can be given as:

=(+1V)d

where,

V = speed of operation, km/h,

d = depth of operation, cm

and , and 1 are soil and tool specific regression

coefficients.

For a given combination tillage implement, can be

expressed by the following function:

= f(d, V, Wi, CI, , w)11


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=

where

p = draft utilization ratio of the rear passive set of

prototype modelr= draft utilization ratio of the reference rear passive set

in reference soil condition,

Wrp = width of the rear passive set of prototype

combination tillage implement,

Wrr = width of the reference rear passive set,

and g, h and i are soil and combination tillage implement

specific regression coefficients.12


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the draft utilization ratio of a reference rear passive set in a

reference soil at different speeds and depths can be

expressed by the following function (Glancey and

Upadhyaya, 1995; Sahu and Raheman, 2004):

r = (d, V)

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EXPERIMENTALPROCEDURE

EXPERIMENTAL SITE:

Laboratory experiments were conducted to find the various

regression coefficients in the soil bin of the Agricultural and

Food Engineering Department, Indian Institute of

Technology, Kharagpur, India.

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SOILBIN

The soil bin comprised of:

a stationary bin,

a common carriage that supports the implement

and soil processing trolleys, power transmission system,

control unit and the required instrumentation

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EXPERIMENTALSETUP

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SOILBINSPECIFICATIONS

The bin was 15.0 m long, 1.8 m wide and 0.6 m deep.

The soil processing trolley comprised of:

a. frame,

b. rotary tiller,

c. leveling bladed. roller

e. water sprayer

A control unit, placed outside the soil bin, controlled the

direction of movement of the soil processing trolley.

The testing tool/implement was mounted on the frame of

the implement trolley, where screw jack arrangements

were provided to vary the depth of operation.17


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SOILDESCRIPTION

The soil at the research farm of the department was an

acid lateritic sandy clay loam.

In order to quantify the soil conditions core sampler and

hand operated soil cone penetrometer were used

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Soil texture Sandy clay loam

sand 57.1 %

silt 19.9 %

clay 23 %

Particle density 2.65 g/cm3

Moisture content 10.3 g/(100 g of dry soil)

cohesion 11.76 kPa

Frictional angle 22.8


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SOILBINPREPARATION

The real soil (sandy clay loam) was collected from the

research farm and filled in the bin up to a depth of 0.5 m

with layers of 10 cm.

The water was sprayed in the bin to get moisture content

close to field capacity.

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Soil depth

(cm)

Particle size

distribution (%)

Bulk density

(g/cm)

Moisture content

(g/100 g of dry soil)

Sand Silt Clay

0-15 57.7 19.7 22.6 1.61 11.3

15-30 55.2 19.4 25.4 1.56 12.1

30-45 52.5 20.2 27.3 1.59 13.2

45-60 52.2 19.2 28.6 1.63 13.8


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SOILBEDPREPARATION

o First the tiller was used to pulverize the soil after

spraying water as desired.

o Then the soil was leveled with the leveling blade and

compacted by the roller to the desired cone index and

bulk density in layers.o At the end of each soil preparation, a hand-operated soil

cone penetrometer was used for measuring the cone

index to a depth of 15 cm at intervals of 2.5 cm at six

locations in the soil bin following the procedures outlined

in the ASAE Standards (ASAE, 2000b).

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TILLAGEIMPLEMENTSUSED

Reference tillage tool

Scale and prototype model of

1. Mould board plough

2. Cultivator

3. Single disc gang

o The two models of combination tillage implement used

in the experiments were:

1. Front mounted mould board plough and rear mounteddisk gang.

2. Front mounted cultivator and rear mounted disk gang.

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Cultivator with disk gang

combination (CTI-1)

Mould board plough with disk

gang combination (CTI-2)


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SPECIFICATIONSOFTILLAGETOOLS

specifications CTI-1 CTI-2

Cultivator Disk

harrow

MB plough Disk harrow

Cutting width (mm) 350 520

No. of cutting elements 2 3 2 3

Diameter of disk (mm) 300 300

Concavity (mm) 30 30

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A frame of 600 mm500 mm was fabricated with 50mm50mm 5 mm mild steel angle for mounting the tillage

implements during the experiment.


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INSTRUMENTATION

The instrumentation for measuring the draft requirements

of reference tillage tool, scale-model individual and

combination tillage implements in laboratory consisted of

an extended octagonal ring transducer and a four-channel

thermal write-out chart recorder with universal amplifier.

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Instrumented three point linkage for measurement of forces indicating

positions of strain gages (4) strain gauge positions for axial force; (5) strain

gauge positions for bending force; (6) strain gauge positions for top link

compressive force.


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26(a) arrangement of strain gauges on lower links; (b) arrangement of dummy

gauges on a plate; (c) circuit diagram for axial force measurements in lower

links; (d) circuit diagram for bending force measurements in lower links.


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Force measurement in top link of a tractor three point linkage system: (a)

strain gauge arrangement in proving ring (b) circuit diagram for axial

force measurement


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28Measurement of draught of tillage implements in the soil bin:

(a) strain gauge arrangements in EORT

(b) Wheatstone bridge circuit


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COMPUTATIONOFDRAFT

Ht = coscos+ cossin- coscos

Where,

Ht = draught, kN;

= tensile force in the lower link,kN;

= bending force in the lower link, kN;

= compressive force in the top link, kN;

= is angle of lower link in the horizontal plane;

= is angle of lower link in the vertical plane;

= angle of top link in the horizontal plane;

= angle of top link in the vertical plane.29


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EXPERIMENTLAYOUT

Laboratory experiments:

Measure draft requirement:

1. two combination tillage implements

2.

three individual tillage implements3. reference tillage tool

at different depths, speeds, bulk densities and cone

indices.

.

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CONTD..

o Soil data were collected using core sampler and hand-

operated soil cone penetrometer before each tillage

experiment.

o The implement trolley along with implement was pulled

in the soil and the draft data from the calibratedextended octagonal ring transducer were continuously

acquired in a four channel thermal write-out chart

recorder after amplification.

o Simultaneously, the time taken to cover a fixed distance

of 10 m was noted.

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FIELDEXPERIMENTS

Field experiments were carried out with 37 kW 2WDtractor to measure the draft requirements of two developed

prototype combination tillage implements.

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CTI 1 CTI 2

specifications Mbplough

Single diskgang

cultivator Single diskgang

Width of cut (cm) 2 30 84 9 25 168

Depth of operation

(cm)

14.5 and 18.8 6.5 and 10


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CONTD.....

o For hard soil condition:

0.25 ha, land after rainy season was selected.

o For soft soil condition:

0.25 ha, land ploughed followed by twice disking

and twice cultivating.

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Soil condition (g/cm) Moisture content Cone index (kPa)

Hard 1.49 12.5 1433

Soft 1.19 11.16 658


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CONTD..

o The draft was measured by employing the electrical

strain gauges on the three-point linkage system of the

tractor.

o The experimental data from the force measuring system

were logged with HP data logger.o Simultaneously, the time taken to cover a fixed distance

of 50 noted was .

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RESULTSANDDISCUSSION

Effect of depth and speed on draft utilization ratio of

reference tillage tool:

Both orthogonal and multiple regression analyses were

performed using a computer-based software (SPSS)package on the average values of the reference tillage

tool (single disk) to determine the speed-depth response

curve in the reference soil conditions.

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REGRESSIONCOEFFICIENTSOFDRAFTUTILIZATIONRATIOFORSINGLEDISKINTHE

REFERENCESOILCONDITION

Regression

coefficients

Orthogonal regression Regression

coefficients

Multiple regression

CTI-1 CTI-2 CTI-1 CTI-2

0.371 0.344 0.478 0.468

1 -0.019 -0.021 1 -0.007 -0.008

0.0 0.0 0.0 0.0

-0.009 -0.011 -0.019 -0.022

4 0.0 0.0 4 0.0 0.0

0.0 0.0 0.0 0.0

R 0.947 0.982 R 0.947 0.982

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Considering the result of multiple regression analysis, the

draft utilization ratio of the reference tillage tool in the

reference soil condition can be calculated:

= +1d+V


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EFFECTOFSCALEFACTORSONDRAFT

UTILIZATIONFACTOR

The value of prototype/scale-model implements at any

speed, depth and soil conditions could be predicted

using

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Combination tillage

implement

g h i R

CTI-1 0 -0.19 0.0 0.897CTI-2 0 -0.38 0.0 0.966

Multiple regression constants of draft utilization ratio for single

disk-disk gang combination based on the reference soil condition


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VALIDATIONOFTHEDEVELOPED

EQUATION

The developed equation predicted the values of the CTI-

1 and CTI-2 with average absolute variation of 2.2 and

4.3%, respectively, from the observed values.

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COMPARISONOFOBSERVEDANDPREDICTED

VALUESOFDRAFTUTILIZATIONFACTOR

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Effect of depth and speed on draft of

combination tillage implements


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From these experimental results, it was found that the

draft contribution of the front passive set to the total draft

of a combination tillage implement was 7585% and 65

80% for the CTI-1 and CTI-2 combination tillage

implement, respectively, and it increased with increasein either bulk density, cone index, depth or speed of

operation.

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VALIDATIONOFTHEDEVELOPED

DRAFTEQUATION

In laboratory:

developed regression equation predicted the draft of the

CTI-1 and CTI-2 combination tillage implement with an

average absolute variation of 14.5 and 13.4%,

respectively.

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COMPARISONOFTHEOBSERVEDANDPREDICTED

DRAFT

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In field:

The developed regression equation predicted the draft of

the C-DH an MBP-DG combination tillage implement with

an average absolute variation of 18.0 and 12.8%,

respectively.

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CONCLUSION

1. New methodology was developed to estimate the draft

requirements of combination tillage implements from the

knowledge of the draft requirements of individual tillage

implements in the same soil and the draft utilization ratio of

the rear passive sets of these combination tillageimplements.

2. From the experimental results it was found that the total

draft requirements of combination tillage implements and

the draft utilization ratio of the rear passive set were

significantly affected by depth, speed of operation and soilcondition.

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3. The developed draft equation estimated the draft

requirements of both combination tillage implements within

an average absolute variation of 18.0 and 13.5%,

respectively, in both laboratory and field conditions.

Hence, the concept of reference tillage tool and referencesoil condition could be used successfully to predict the

drafts of various combination tillage implements and draft

utilization ratio for rear passive set of the combination

tillage implement in field conditions. This concept could

save time, energy and cost by reducing the number of fieldexperiments.

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REFERENCES

Sahu, R.K., Raheman, H., 2004. Possibility of using

passivepassive combination tillage implements for

Indian farming system. In:Proceedings of International

Conference on Emerging Technologies in Agricultural

and Food Engineering (Etae-2004), vol. (1), IIT,Kharagpur, 1417 December, pp. 100106.

ASAE Standards, 2000a. ASAE D497.4. Agricultural

machinery ASAE Standards, 2000b. ASAE S313.3. Soil

cone penetrometer. St. Joseph, Mich.: ASAE.

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Documents

Draft Prediction of Combination Tillage Implements