solar grass cutter machine paper presentation in NACCTEST-2018

1. Impact factor: 3.441 e-ISSN: 2456-3463
National Conference on Current Trends in Engineering, Science and Technology (NACCTEST- 2018)
Organized by GF’s Godavari College of Engineering, Jalgaon
International Journal of Innovations in Engineering and Science, Special Conference Issue, 2018
www.ijies.net
1
SOLAR BASED GRASS CUTTER MACHINE
Sachin Maheshri1
, Ritesh Patil 2
, Hemant Avasrmal 3
, Shubham Bhad 4
1
Assistant Professor Of Electrical Department
2,3,4
Student, Electrical Department
Gf’S Godavari College of Engineering, Jalgaon, India, 425003
1) rdpatil1803@gmail.com 2) shubhambhad76@gmail.com
Abstract – In today’s generation the major problems are
the pollutions, cut of power etc. Thus overcome to these
problems we have thought about device which can be
work efficiently without causing any types of problem. So
we work on the project of grass cutter machine which
performing fully automated and using renewable source
of energy that is solar power. The main object of this
project is to invent solar operated grass cutting machine
which is operated on the solar power. There is power
shortage therefore we decide to work on the device
which operated on solar power. And if the some
condition there is solar power will be not done we use
the external power supply, for that we make the external
power supply circuit. This project working is easy and
simple in construction. In this project we use the solar
panel which is connected to the battery where the battery
supplies the power to the whole arrangement. In this
project we connect the four motors where the two motors
for moving action and other two motors for the cutter
blades. So from this paper we present the daily purpose
robot which cuts the lawn.
Keywords- Solar Plate, Battery, Blades, Atmega8
Microcontroller, Sensors, DC Motor, Voltage
Regulator, Sensor.
INTRODUCTION
Solar energy is the form of renewable energy source
and this source is characterized as either passive
solar or active solar depending on how they capture and
distribute solar energy or convert it into solar power.
Basically solar energy is the free energy source which
can be used easily. Then by using this free solar energy,
solar based grass cutter machine will be operating
automatically. Generally in the market there are many
grass cutter machines are available like electrical and
gasoline based. The gasoline grass cutter machine fully
depends on the fuel means it works on the fuel which
increases the air pollution. And the electrical grass cutter
machine fully depends on the electricity provide by the
electrical motor that is induction motor.
For this cutter machine long wire required for the
power supply and due to the high weight of induction
motor, it is difficult to operate. If think about these
problems, try to make grass cutter machine on fully
automated based on the solar power. In this project the
10 watt solar panel used for the power supply and 12V
battery used for storing the solar power.
There are four motors are used which are controlled
by the Atmega8 microcontroller. Where the two motors
are used for the moving action and the other two motors
used for grass cutting purpose. For avoiding the
obstacles during the operation the ultrasonic sensor is
used for avoiding action. There is no need of fuel and
any wire extension for the power supply therefore it is
pollution less and eco-friendly project.
METHODOLOGY
The solar panel mounted on the grass cutter machine
receives the solar power from the sun. This solar power
stored in the battery. The battery provides power supply
by using the solar charge controller. The main function
of the solar charge controller is to increase the current
from the panels while batteries are charging, it also
disconnects the solar panels from the batteries when they
are fully charged and also connects to the panels when
the charging in batteries is low [2].
The solar grass cutter machine is start operation by
the switch connected on the board which allows the flow
of current to the motor which in turn drive the blades
used for moving[5]. In this solar grass cutter machine
the four dc 12v motors are connected to the both side of
the machine, per side two motors are connected in
parallel connection so they works as a single unit on
both side [1]. Other additional motors are connected at

2. Impact factor: 3.441 e-ISSN: 2456-3463
National Conference on Current Trends in Engineering, Science and Technology (NACCTEST- 2018)
Organized by GF’s Godavari College of Engineering, Jalgaon
International Journal of Innovations in Engineering and Science, Special Conference Issue, 2018
www.ijies.net
2
the front of the frame; these motors have connected
blades on the motor shaft so that the grass is cut by turn
on these motors. These motors are operated by the
Atmega8 micro-controller; it gives the forward moving
command to the motors. During the operation of this
grass cutter if the obstacle comes in front of machine the
Atmega8 micro-controller give the command to the
SR04 ultrasonic sensor and this sensor detect that
obstacles and avoid them and change the direction of
grass cutter machine. The components used in this
project are 12V 10watt solar panel, 12V battery,
LM7805 voltage regulator, Atmega8 micro-controller,
SR04 ultrasonic sensor, DC motors.
I. Block Diagram
The block diagram show in the below is present the
constructional block diagram and the required
components to the solar grass cutter machine.
Fig.1 Block diagram of solar grass cutter machine
In the above constructional block diagram, the solar
panel mounted on the battery where the battery charge
by the solar power which captured from the solar panel.
There are LM7805 voltage regulator connected to the
battery which generate the fixed output voltage to micro-
controller. The two motors connected to the driver
circuit and the blades connected to the other two motors
that is cutter motors.
Components used in this project are as follows:
I. Solar Panel:
The typical 12V 10 watt 6x10 solar panel is used in
this project. The solar panel can be used as a component
of a larger photovoltaic system to generate and supply
electricity in commercial and residential applications [2].
In order to run a mechanism the motor required 12 volt.
And Variable current so that we are storing that power in
to battery in order to run the mechanism.
Our battery capacity is 12 volt and 7.5 amps.
Hence power is calculated by = Voltage*current
= 12*7.5
=90 watt (In a single battery)
In order to store this much of power in battery we
required time.
Total battery power =Power generation of panel per
hour*Time
Hence 90watt. =10*Time
Time=9 Hour [5]
Fig. 2 Solar panel
The specification of this solar panel are;
1) AP Mono crystalline Blue Solar Cell
2) Peak Voltage ( ): 12V
3) Open Circuit Voltage ( ): 6.0V - 6.8V
4) Peak Current ( ): 400mA
5) Short Circuit Current ( ): 400mA - 432mA
6) Maximum Power ( ): 2.5W [1]
II. Atmega8 micro-controller :
The micro-controller used in this project is Atmel
AT89S52 microcontroller. This micro-controller is a
powerful microcontroller which provides a highly-
flexible and cost-effective solution to many
embedded control applications.

3. Impact factor: 3.441 e-ISSN: 2456-3463
National Conference on Current Trends in Engineering, Science and Technology (NACCTEST- 2018)
Organized by GF’s Godavari College of Engineering, Jalgaon
International Journal of Innovations in Engineering and Science, Special Conference Issue, 2018
www.ijies.net
3
The AT89S52 micro-controller provides the
following standard features:-
1) 8K bytes of Flash
2) 256 bytes of RAM, 32 I/O lines
3) Watchdog timer
4) Two data pointers
5) Three 16-bit timer/counters
6) A six-vector two-level interrupt
architecture
7) A full duplex serial port
8) On-chip oscillator
9) Clock circuitry.
III. DC motors:
The 12V permanent magnet dc motors are used in
this project. If the current carrying conductor placed
in the magnetic field, it cuts the magnetic field and
produce magnetic flux. It experiences the torque and
the tendency of moving action therefore it has called
as motoring action.
Fig.3 dc motor
IV. LM7805 voltage regulator:
Here the three terminal voltage regulator are used
for the stable dc voltage. The LM7805 is the three
terminal positive regulators available in the TO-220
package and with several fixed output voltages,
making them useful in a wide range of application.
Depending on the design, it may be used to regulate
one or more AC or DC voltages. Any difference is
amplified and used to control the regulation
element. [1]
V. Power Supply:
The designed power supply is made up of solar
panel, which gives 12V 10W as output. This 12v
output is capable of running motors, relays blades
and pumps. All the other circuitry is given a
regulated voltage of +5V. [1]
VI. Ultrasonic sensor:
The sensor used in this project is SR04 ultrasonic
sensor for detection of the obstacles. This device
generates the ultrasound waves by using the
electrical energy. It also converts ultrasound
vibrational energy into electrical signals. Normally
in the ultrasound switches the barium titanate
transducer applying piezoelectric effect is used.
Fig.4 Ultrasonic sensor
VII. Circuit Diagram
Fig.5 Circuit Diagram Of The System
This circuit is implemented by making use of the
transformer (220V/12V), Rectifier, Filter, Voltage
regulator, Comparator, Transistor and Relays. The
selection of equipment with proper rating is done by
calculating their minimum and maximum rating of
voltage and current across them under normal as well as
abnormal operating conditions and proper care is taken
in selection of the transformer as it is acting like
interface between the electrical and electronics circuit
used. The protection of delicate ICs must be ensured.

4. Impact factor: 3.441 e-ISSN: 2456-3463
National Conference on Current Trends in Engineering, Science and Technology (NACCTEST- 2018)
Organized by GF’s Godavari College of Engineering, Jalgaon
International Journal of Innovations in Engineering and Science, Special Conference Issue, 2018
www.ijies.net
4
DESIGN ANALYSIS
Theoretical
I. General analysis:
The shearing force of most annual and perennial grasses
found on most lawns is usually between 9.2N ~ 11.51N
(Yong and Chow, 1991)[3].
Force required by cutting blade to shear the grass is
given by;
F =T/R…………………………….. (1)
Where T = Shaft torque; R = Radius of cutting blade
But shaft torque is given by;
T = P/2πN ………………………… (2)
Where P = Power developed by shaft; T = Torque
required; and N = Shaft speed in Rev/min [3].
II. Power Transmission
Power transmitted from the motor to the blade is given
by;
P = (T1 – T2) v
(Khurmi, 2003)
Where T1 = Tension on tight side of belt
T2 = Tension on slack side of belt, and P = 932.5 N
Use was made of group A, v-belt design having a power
transmission range of 0.7 ~ 3.5 kW.
2.3 log (T1/T2) = μθcosecβ
(Khurmi, 2003)
Sinα = (R1 – R2) /C = (60 – 40) /180 = 0.1111; α = 6.380
Where R1 and R2 are rad. of pulleys 1 and 2
respectively.
Angle of contact,
θ = 180 - 2α = 180o – 2(6.38) = 167.240
θ = 167.240
(π/1800
) = 2.92 rad.
2.3 log(T1/T2) = μθ cosecβ;
where μ = 0.2 and 2β = 340
Thus, T1/T2 = 7.379; T1 = 7.379T2
P = (T1 – T2) v ;
where P and v are transmitted power and peripheral
velocity respectively.
932.5 = (T1 – T2) x 15.71
T1 – T2 = 59.36 N
7.379 T2 – T2 = 59.36;
T2 = 9.3N and T1 = 68.66N
Centrifugal tension in the belt is given by;
= mv2
where m = mass of belt per meter, and v = peripheral
velocity.
= (1.06/9.81) kg/m x 15.712 = 26.67N
[3].
III. Power Selection
The force required to cut grass by a sharp object should
not be less than 10Newtons, this is subjected by factors
such as: the height of the grass, type as well as grass
density in the area. However a slightly bigger force will
be required (or selected) for high efficiency.
Considering the blade in concept three;
Area of blade = 0.24m2
Volume of blade = Area of blade x Thickness
= 0.00176m3
Density = mass/volume
= 1001.7 kg/m3
Thus, Mass of blade = 1.763kg;
Force = 1.763 x 9.81= 17.295N
Torque required to turn the blade = Force x Radius of
blade
= 17.295 x 0.331
= 5.725 Nm
Thus, depending on the density of grass, the minimum
power required to move the blade in 1 second is
1.8Watts. Tanimola, et al (2014). This is quite a small
value, but it plays an important role in selecting the
power needed. According to Tanimola, et al (2014), the
greater the power, the greater the efficiency. Hence,
considering the power required to move the blade. [6]

5. Impact factor: 3.441 e-ISSN: 2456-3463
National Conference on Current Trends in Engineering, Science and Technology (NACCTEST- 2018)
Organized by GF’s Godavari College of Engineering, Jalgaon
International Journal of Innovations in Engineering and Science, Special Conference Issue, 2018
www.ijies.net
5
The strength and density of grass as well as efficiency
and factor of safety in design, 2.1 kW is selected. This
will be able to handle different types of grass at
expectedly high efficiency. [6]
IV. Design of Blades
In order to cut the grass the peripheral speed of the blade
was calculated by the formula,
V = π d N
60
Where,
V= blade speed, m/s; d = diameter of cutting area.
N = shaft speed, rpm. [4]
PROJECT IMPLIMENTATION PICTURE
CONCLUSION
This project provides a design method of an
automated grass cutter operated on solar power, whose
task is to cut grass with no need of user interaction. This
task is expected to be made possible by using sensors to
provide an arduino with controlling.
The obstacle is automatically avoided; here for
obstacle avoidance the ultrasonic sensor is used. The
system also provides power backup by using inverter.
The proposed system will be cost efficient with higher
reliability.
ACKNOWLEDGMENT
I has been sincere desire of every individual to get
an opportunity to express his views, skills, attitude and
talent in which his proficient to give his satisfaction and
confidence in his ability to do or produce something
useful for humankind. A project is one such avenue
through which an engineer gives vent to his feeling and
expressions.
We wish to thank our project guide PROF.
SACHIN MAHESHRI (Asst. prof. of electrical dept.)
for his valuable suggestion and inspiring guidance. We
are thankful to honorable Principal DR.
V.G.ARAJPURE for their precious time whenever we
wanted any help from them. They are also helpful in
giving professional ideas and technical references.
We also express deepest thanks to HOD of
electrical dept. PROF. ATUL BARHATE & staff
members concerned who have meticulous planning
created a comfortable co-existence of the projects and
college schedule.
Last but not least we are also thankful to our
friends who gave us their help and great co-operation to
make our project successful directly and indirectly.
REFERENCES
[1] International Journal on Recent and Innovation Trends
in Computing and Communication ISSN: 2321-8169
Volume: 4 Issue: 3.
[2] International Journal of Research in Advent
Technology (IJRAT) (E-ISSN: 2321-9637) Special Issue
National Conference CONVERGENCE 2016”, 06th-
07th April 2016.
[3] International Journal of Engineering and Technology
Volume 3 No. 10, October, 2013 ISSN: 2049-3444 ©
2013 – IJET Publications UK. All rights reserved. 933
“ Simple Design of Self-Powered Lawn Mower
[4] International Journal of Agriculture Sciences ISSN:
0975-3710&E-ISSN: 0975-9107, Volume 9, Issue 40,
2017, pp.-4638-4641
[5] International Journal For Technological Research In
Engineering Volume 3, Issue 10, June-2016 ISSN
(Online): 2347 – 4718
[6] Elk Asia Pacific Journal Of Mechanical Engineering
Rresearch Issn 2394-9368 (Online); Eapjmer/Issn.
2394-9368/2016; Volume 2 Issue 1 (2016).