This presentation has covered the following topics related to Agricultural Engineering: Machine performance, Time efficiency, Factors affecting field efficiency, Field shape and size, Ergonomics, Rolling resistance.

1. WEL-COME

2. PRESENTATION
ON
FACTORS AFFECTING FIELD PERFORMANCE,
ERGONOMIC PERFORMANCE &
ROLLING RESISTANCE
Course title: Farm Power & Machinery
Management
College of Agricultural Engineering and
Technology, Dr. PDKV Akola, 444104 (M.H.)

3. CONTENTS
oMachine performance
oTime efficiency
oFactors affecting field efficiency
oField shape and size
oErgonomics
oRolling resistance

4. MACHINE PERFORMANCE
 Measures of machine performance are :
I. Rate &
II. Quality at which operations are
accomplished.
 Rate is reported in terms of quantity per
time.
 Quality as well as quantity must be
considered when evaluating machine
performance.

5. TIME EFFICIENCY
 Time efficiency is a percentage
reporting the ratio of time a machine is
effectively operating to the total time a
machine is committed to the operation.
 Any time the machine is not actually
processing the field is counted as time
waste .

6. FIELD EFFICIENCY
 Definition:
 They are not constant values for specific
machines and varies widely.
 Examples : Field efficiency of MB plow=88-74%
Combine harvester =90-93%.

7. FACTORS AFFECTING FIELD EFFICIENCY
Theoretical capacity
Machine maneuverability
Field patterns
Field shape
Field size
Yield
Soil and crop conditions
System limitations

8. FIELD SHAPE
The field efficiency decreases with
irregularities in field shape.
It is expected significantly less in irregularly
shaped fields than in rectangular fields
because of excessive turning time.
Even if the field boundaries of irregular
shaped fields are straight the ratio of
turning time to operation time will be
high.

9. All the patterns are possible in the irregularly
shaped fields.
Continuous pattern used with two way plow
has greatest efficiency.
A headlands pattern if selected, headlands
should be perpendicular to back furrows.
The 3π/2-rad circuitous type pattern is almost
impossible from centre of field, but pattern
may be started from the boundaries of field.
POSSIBLE FIELD PATTERNS

10.  Long fields improve the field efficiency significantly.
 E. S. Renoll (Auburn University) Found sizable
differences in the proportion of turning time required for
irregular fields with different row length:
Field A Field B
Range in row
length, ft
165-400 1000-1060
Turning time, %
total time
20 3
Field capacity,
a/hr
1.9 2.9

11. Comparison illustrates a general truth-
If two sides of field are perpendicular, the
machine pattern should be operated parallel to
the longer of as these two sides for greater
efficiency as only one angled headland is
encountered.
If triangular field has no right angles, the
machine pattern should be parallel to the longest
side to reduce the number of angled headlands.

12. For right angled fields the machine swath is
parallel to the hypotenuse.

13. FIELD SIZE
Large fields do not necessarily have greater
efficiency than the smaller ones.
If dimension of field is doubled and width of a
tillage implement is also doubled.
The pattern efficiency remains the same if
forward speed remains the same and turning
radii are identically proportional to width.
But if the width of implement remains
unchanged, the field efficiency will improve
because the proportion of implement operating
time increases with respect to its turning time.

14. ERGONOMICS
What is ergonomics?
Ergonomics is an applied science for
adjusting work to man in the light of his anatomy,
physiology and psychology.
OR
Ergonomics is study for people’s efficiency in
their working environment.
o It aims at:
 To enhance effectiveness & efficiency with which
work is carried out
 To maintain or enhance such human values as safety,
health & job satisfaction.

15. CONSIDERATIONS IN DESIGN
The various considerations can be grouped into
3 major categories:
1. Man-machine system
2. Physical environment
3. Safety and health
Man-machine systems:
There are 4 types of systems:
1) Manual system
2) Man-animal-machine system
3) Mechanical system
4) Automatic system

16. WORKLOAD
 Physical workload:
 The human body provides a power to locomotors
system(muscles & skeleton tissues) using oxygen and
food.
 The efficiency of this human machine is only 25%.
 Physical workload is expressed in terms of cardio-
respiratory responses of the workers.
 The main physiological parameters measured are-
(a) Heart rate
(b) Oxygen consumption.

17.  The heart has been referred to as the primary indicator
of the strain or the physiological reaction of a specific
person to a stress of environment.
 Heart rate is the number of ventricular beats taken by
the subject per minute.
 H. R. can be measured & analyzed easily in practice
without disturbance to the worker by USING POLAR
HAERT MONITOR.
 It consist of a chest belt & wrist receiver.
 The chest belt having inbuilt electrodes fitted on the
chest and the wrist receiver of the monitor is fitted on
the wrist of the subject.
HEART RATE

18. Before the start of the experiment the subject are
given a rest of 30 min for getting normal starting
heart rate.
The heart rate during working is noted which is
called as working heart rate.
The difference between the working H. R. &
starting H. R. is called as increase in heart rate
or work pulse.
With the polar heart rate monitor, the heart rate
can be recorded per sec.
MEASURING HEART RATE

19. OXYGEN CONSUMPTION
 The difference between the oxygen content of the
inhaled & exhaled air multiplied by the volume the air
passing through the gas meter gives a measure of the
total oxygen consumed.
 The consumption of oxygen by subject in a given
time(per minute) is termed as oxygen consumption
rate expressed in lit/min.
 It is correct variable for measuring the physiological
work load but it is difficult to measure it while
performing the work.

20. MEASUREMENT OF OXYGEN CONSUMPTION
Indirect method i.e. estimation of oxygen
consumption using correlation using correlation
between heart rate and oxygen consumption is
used.
The oxygen consumption from the heart rate can
be determined by using following equation:
Y = 0.0162X – 1.314
where,
Y= Oxygen consumption rate, lit/min
X= Heart rate in beats/min

21. HUMAN LIMITS
 Human limit are nothing but the physical
and physiological capabilities of individuals.
 It depends on anthropometry, edurance
limit metabolic process and maximum
aerobic power physics and stamina.

22. ROLLING RESISTANCE
.Rolling resistance or rolling friction is the force
resisting the motion when a body is rolls on a
surface.

25. The operation of equipment over typical
farm ground involves concepts of rolling
resistance & weight components.
Rolling resistance is the force required to
keep the equipment moving at a constant
speed and is proportional to equipment
weight.
Need of force- To provide the energy
required to deflect rubber tires, to
compress or push aside soft soil, to
overcome wheel- & axle-bearing friction.

26.  Coefficient of rolling resistance – The ratio
of the horizontal force(draft) required to a
pull a loaded wheel over a horizontal
surface to the vertical force on that wheel’s
axle.
 In customary units this ratio is pull/weight.

28. THANK YOU