mobile operated lawnmower - ijmerr · all the above systems are controlled by the micro controller....

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Int. J. Mech. Eng. & Rob. Res. 2014 K Prasada Rao et al., 2014

ISSN 2278 – 0149 www.ijmerr.com

Vol. 3, No. 4, October, 2014

© 2014 IJMERR. All Rights Reserved

Research Paper

MOBILE OPERATED LAWNMOWER

K Prasada Rao1* V RamBabu1, K Santa Rao1 and D Venkata Rao1

*Corresponding Author: K Prasada Rao � [email protected]

Lawnmowers are the grass cutters which are used to cut the grass in the fields. Now a daysgrowing grass became interior decoration for the companies, colleges, and various other places.But to maintain this grass in a proper way we need grass cutters. In the early 1827’s lawnmowersare used as conventional grass cutters. Later, in order to improve its efficiency and automatethe process of grass cutting various new technologies such as remote operated lawnmowersarrived. In remote operated lawnmowers the range of grass cutting equipment is limited as thesignal strength is very weak and also the equipment required for these lawnmowers issophisticated and expensive. In this work to overcome these limitations remote controlled lawnmower is incorporated with a mobile phone which acts as a link between user and grass cutter.Inthis work, two mobile phones are used in which one acts as a transmitter and the other as areceiver. Mobile phone that makes a call to the mobile phone attached to the circuit of lawnmower.In the course of a call, if any button is pressed, a tone corresponding to the button pressed isheard at the other end of the call. This tone is called ‘dual-tone multiple-frequency’ (DTMF)tone. The microcontroller perceives this DTMF tone with the help of the phone stacked in thelawn mower. The received tone is processed by the microcontroller with the help of DTMFdecoder MT8870. The decoder decodes the DTMF tone into its equivalent binary digit and thisbinary number is sent to the microcontroller. The microcontroller is preprogrammed to take adecision for any given input and output. It’s decision to motor driver in order to drive the motorfor forward or backward motion or a turn. The cutter is turned on or off with the help of a mobilephone by a number which is instructed in the program. The mobile that makes a call to themobile phone stacked in the lawn mower acts as a remote and performs the function of a grasscutter.

Keywords: Lawn Mower, Mobile phones, Rechargeable, Cutting Efficiency, Surgical Blade

INTRODUCTION

The aesthetic value of this environment is asimportant as food and shelter to the modernman. In general, grasses are found to survive

1 Department of Mechanical Engineering , GMRIT-Rajam, INDIA-532127.

in a variety of conditions and thus the needto curtail their growth in order to enhance thebeauty of our habitat environment. As manevolved intellectually, grass cutting inevitably

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developed to an art. As technology advancedgrass cutting developed, away from use ofmachetes, hoes and cutlasses to motorizedgrass cutters. Technology had continued toadvance and better techniques of grasscutting has been invented and constantlyimproved upon. This gave birth to theinvention of lawn mower. A lawn mower is amachine used for cutting grass or lawns. Alawn is any area of grass; mostly tough grasswhich is neatly cut like in a private garden ora public park.

The first lawn mower was invented in 1830by Edwin Beard Budding.(Passmore, EverettG et al., 1879). He said that he obtain theidea after watching a machine in a local clothmill which used a cutting cylinder mountedon a bench to trim clothes for a smooth finishafter weaving. Budding realized that a similarconcept could be used to cut grass if themechanism is mounted in a wheel frame toenable the blades rotate close to the lawnssurfac.

Thomas Green patented the first lawnmower to be driven by chains, a fundamentaldevelopment named Silent Messer whichimplies silent running. In 1861 Ransomes re-entered the lawn mower market with theirnow improved machine. Although Ransomesin 1867 introduced a totally new design ofmower, the Automaton which became aninstant success with over 1,000 machinesbeing sold in the first season. This designwas to put Ransomes level with the other twomain producers, Shanks and Green. Followsand Bates entered the market in 1869 with amower called the Climax. This machine wasa major innovation - the land roller wasremoved and replaced by two land wheels

placed on the outside of the side-frames. Agear inside the land wheel drove the cuttingcylinder andthe machine had fewer parts andwas much lighter and cheap in costs.It wasshown at the International Exhibition of 1862along with Shanks, Ferrabee and Green.(Hall and Duck Trust et al., 2011).

By late 1890, motorized mowers appearedas light weight petrol engines and smallsteam power units became available.Gasoline powered lawn mowers were first,manufactured in 1914 by Ideal Power. IdealPower Mower also introduced the world’s firstself-propelled, riding lawn tractor in 1922,known as the “Triplex. In US, Colonel EdwinGeorge produced the first gasoline poweredmower in 1919. Electric powered mowers androtary cutting machines emerged in the1920’s and 1930’s.

The objective of this paper, is to controlthe motion of robot by a mobile phone (astransmitter) that makes call to the mobile-phone (as receiver) attached to the robot.Control of rover is done by any mobile devicethat does not restrictits motion. Mowing thelawn with a standard motor powered lawnmower is an inconvenience, and no one takespleasure in it and cannot be easily accom-plished by elderly, younger, or disabledpeople because they can some- times causedanger. The blades of self-powered pushmowers (gas oline or electric) can injure acareless or in attentive operator; as such,many come equipped with a dead man’sswitch to immediately disable the bladerotation when it is not being operated. In theUnited States, over 12,000 people per yearare hospitalized as a result of lawn moweraccidents (Costilla V and Bishai D M, 2006)

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Motor powered push lawn mowers and ridinglawn mowers create noise pollution due tothe loud engine, and local air pollution due tothe combustion in the engine. Also, a motorpowered engine requires periodic main-tenance such as changing the engine oil.Even though electric lawn mowers are envi-ronmentally friendly, they too can be aninconvenience. Along with motor poweredlawn mowers they also hazardous and cannotbe easily used by all. Also, if the electric lawnmower is corded, mowing could prove to beproblematic and dangerous. The transitionfrom traditional hand-guided or ride-onmowers to automaticelectric mowers isbeginning to take place, with the growth inrobotic lawn mower sales of 2012 (Kinnanderand Ola, 2012). The self-propelling electricand mobile operated lawn mower is roboticuser friendly, cost efficient, safe to use,efficient to use, environmentally friendlyandcan reduce noise pollution and no need offuel and engine (Cheryl Springfels et al.,2011).

Along with the various ages of users, thislawn mower can also be used by people whohave disabilities and are unable to use aregular push, or riding lawn mower. Theprototype will also be automatic and will runon a charged battery with no cords to interferewith operation this cordless electric lawnmower includes control capability throughmobile phones which is less expensive thana robotic lawn mower with sensor capability(Hollis and Scott, 2005). With its controlcapability the lawn mower stays within theboundaries of the lawn because the user isable to have control over the lawn mower withthe controller.

The main objective to extend the designof currently used lawn mower, and to improvethe capabilities of standard robotic lawnmowers by increasing its range as well asassuring cost efficiency. Most consumers willbe able to use this device as it is safe to use,as well as efficient because it electricpowered and cordless.

All the above systems are controlled bythe Micro controller. In our project we areusing the popular 8 bit micro controller AT89C51. It is a 40 pin micro controller. TheMicro controller AT89C51 is used to controlthe dc motors. It gets the signals from theDTMF decoder and it drives the moto rsaccording to the DTMF in puts. Two D Cmotors a reused to drive the rover in fourdirections i.e. Front, Back, Right, Left. Withthe instructions given to micro controllerthrough program it is moved along the lawnand performs the grass cutting operation byusing a two surgical blades which acts as acutter which are separated by 180 degrees.

BLOCK DIAGRAM DESCRIPTION

The block diagram of the micro controllerbased mobile operated lawn mower. In thisthe total equipment is run through the 2mobile phones which are equipped with theheadset in which one mobile act as trans-mitter and the other as a receiver. The impor-tant components used to run the cutter alongwith moment of chassis is micro controllerwith DTMF decoder and motor driver. An MT8870 Series DTMF decoder is used here.DTMF signaling is used for telephonesignaling over the line in the voice frequencyband to the call switching center. The versionof DTMF used for telephone dialing them

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obilet hat makes a call to th e mobile phonestacked in the robot acts as a remote is knownas touch tone. DTMF assigns a specificfrequency (consisting of two separate tones)to each keys that it can easily be identifiedby the electronic circuit. Here the decoderconverts the input signal into output signalsinform of the hex file which is programmedby using the KILE software. And the inputprogram used is instructed according to theinformation that is given to mobile phonesthat is the directions are controlled throughbuttons on the mobile phone. And the outputis received through another mobile which actsas a receiver. According to the outputreceived by mobile phones the motor driverdrives the cutter and the wheels and performsthe operation of cutting or the moment of thechassis in desired directions. (PRaghavendra Prasad and K Susram Rahul,2008).

In this work we programmed to have left,right, front, backward directions for thenumerical key 4,6,2,8 respectively. And soon and off the motor we have used 5 and toswitch on or off the cutter 0 is used. Thus thecontrolled movement of the chassis isperformed.

HARDWARE COMPONENTS

• Chassis

• Wheels

• Grass Cutter

• DC Motors

• Power Supply

• Arduino-uno

• 2 Mobile Phones

Chassis

The material of the Chassis is of plywoodbecause and it is rectangular shaped. And itis provided with spaces for mounting compo-nents. Ithas more strength and has moreresistant to vibrations which are created dueto the moments of chassis and it has morestiffness than that of Steel. And it is excellentcorrosion resistance. The main physicalproperties are low density, durable, ductile,malleable. It has the temperature resistanceupto 100-1600c and does not affect toplywood size. The front wheels to drive, andback wheels to make a turn. And the wholemoment of the chassis is dependent on thecircuit of Arduino - Uno.

Table 1: Mechanical Properties of Wood

S.No.1

2

3

4

5

TERMSMoisture content

Glue shear strength in dry condition

Glue shear strength in wet condition

Glue shear strength in

Tensile strength1.Parallel to gain direction2.Right angle to gain direction3.Sum of two directions

ISI REQUIREMENTS15%

Individual Min-1078.7 NAverage Min.- 1329.9 N

Individual Min- 784.5 NAverage Min.- 580.7 N

Individual Min- 784.5NAverage Min.- 580.7N

Min - 470 Kg/cm2

Min - 250 Kg/cm2

Min - 845 Kg/cm2

RESULTS7.20%

1450 N1700 N

1250 N1420 N

1120 N1300 N

645 Kg/cm2

395 Kg/cm2

1040 Kg/cm2

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Figure 1: Block Diagram of MobileOperated Lawnmower

Figure 2: Chassis

Figure 3: Straight Type Tyres

Wheels

When constructing any robot, one majormechanical constraint is the number there atwo-wheel drive or a four-wheel drive. Thoughfour-wheel drive is more complex than two-wheel drive, it provides more torque and goodcontrol. Two-wheel drive, on the other hand,is very easy to construct.

Wheels are classified based on theirDesign of land. The Various types are straighthelical. And they are also classified Basedon their applications Such as Tuberouswheels which are used on hilly areas andhighly stone areas.

In this work used helical types of wheelsso that they can easily move on high hill areasand heavy bush places without any obstruct.

Grass Cutter

A Lawn mower is a machine that uses one ormore revolving blades to cut a lawn to aneven height. The blades may be poweredeither by hand by pushing the mower forward,or may have an internal combustion engineto spin their blades. Some mowers alsoinclude other abilities, like mulching orcollecting their clippings.

Two main styles of blades are used in lawnmowers. Lawn mowers employing a singleblade that rotates about a single vertical axisare known as rotarymowers, while thoseemploying a multiple blade assembly thatrotates about a single horizontal axis areknown as cylinders or reel mowers.

There are several types of mowers, eachsuited to a particular scale and purpose. Thesmallest types are pushed by a human userand are suitable for small residential lawns

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and gardens. Riding mowers are larger thanpush mowers and are suitable for large lawns.The largest multi-gang mowers are mountedto tractors and are designed for large expan-ses of grass such as golf courses and muni-cipal parks.

Figure 4: Surgical Blades

In this work 2 surgical blades are usedwhich is carbon steel and low weight. Sandvikprovides hardened and tempered cold-rolledstrip steel used for surgical scalpel blades.Here we use single blade cutter and corrosiveresistances and it has excellent edge proper-ties, and enables grinding, high sharpness,tough and stable edge. Even with low speedthe grass can be cut very easily. And thus itincreases the efficiency of grass cutting.

Grade and their Description

Sandvik Bio line 13C26: Martensiticstainless chromium steel which afterhardening is characterized by very high hard-ness and wear resistance and good corrosionresistance.

Sandvik 13RM19: An austenitic stainlesssteel combining high mechanical strength

with a non-magnetic structure. The grade hasgood fatigue properties and excellent ductility.

Sandvik Bio line 4C27A: The hardenedstainless chromium steel characterized byvery good machinability. It has highhardnessand high wear resistance after hardening.

Table 2: Components and theirPercentges in Carbon Steel

Components

C

Fe

MN

P

Pb

S

Weight%

Max 0.15

97.91 - 98.7

0.85 - 1.15

0.04 - 0.09

0.15 - 0.35

0.26 - 0.35

Table 3: Mechanical Propertiesof Carbon Steel

Hardness, Rockwell B

Density

TensileUltimateStrength

Tensile Yield Strength

Elongation at Break

Modulus of Elasticity

Bulk Modulus

Poisson's Ratio

Shear Modulus

84

0.284 lb/in³

540 MPa

415 MPa

10%

200 GPa

140 GPa

0.29

80 GPa

Motor

A unit which creates mechanical energy fromelectrical energy and which transmits mecha-nical energy through the gear box at a reduc-ed speed is a Gear motor. A gear head andmotor combination is to reduce the speed ofthe motor to obtain the desired speed ortorque.

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Figure 5: Motor

Gear motors of all types and sizes includesingle/ multiphase, universal, servo, inductionand synchronous types. DC gear motors areconfigure dinmanyty pes and sizes, includingbrushless and servo. A DC gear motorconsists of a rotor and a permanent magneticfield stator and an integral gearbox orgearhead. The magnetic field is maintainedusing either permanent magnets or electromagnetic windings. DC motors are mostcommonly used invariable speed and torqueapplications. ADC servo motor has an outputs haft that can be positioned by sending acoded signal to the motor.

As the input to the motor changes, theangular position of the output shaft changesas well. Servo motors are generally small andpowerful for their size, and easy to control.Common types of DC servo motors includebrushless or gear motor types. Steppermotors are classes of motors that provideincremental motion, or steps, in response topulses of current that alternately change thepolarity of the stator poles; step motors donot require feed back and are sometimesused in “Open Loop,”

Important performance specifications toconsider when searching for gear motorsinclude shaft speed, continuous torque, andcontinuous current and continuous outputpower. The terminal voltage is the design DCmotor voltage. The continuous torque is theoutput torque capability of the motor underconstant running conditions.

Continuous current is the maximum ratedcurrent that can be supplied to the motorwindings without over heating. Continuousoutput power is the mechanical powerprovided by the motor output.

Important DC motor specifications toconsider include terminal voltage, motorconstruction and commutation. The terminalvoltage is the design DC motor voltage. Motorconstruction choices include permanentmagnet, shunt wound, series wound, compound wound, discarmature, and coreless orslotless. Important gearing specifications toconsider for gear motors and gear headsinclude the gearing arrangement, gearboxratio, and gearbox efficiency. Gearingarrangement choices for gear motors orgearheads includes pur, planetary, harmonic,worm, and bevel. Gearbox ratio is the ratioof input speed to output speed. A ratio greaterthan one, therefore, indicates speedreduction, while a ratio less than oneindicates speed increase. Efficiency is thepercentage of power or torque that istransferred through the gearbox. Lossesoccur duet of actors such as friction andslippage inside the gearbox.

In this work two types of motors are used

• Cutter motor: 12000 rpm motor withtorque less and should resist the cutterweight

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• Drive motor: 200 rpm with 5 kg torqueand it should resist the weight of thechassis and can able to resist thevibrations during operation

Power Suuply

Here using rechargeable batteries as meansof power supply. There are 2 batteries, inwhich one battery is of a 12v 1.3AH batteryto run motor which used drive the chassisthat is 4 wheels and cutter. And we are using.

When acsign alisgivent ot he primary ofthe transformer due to the magnetic effect ofthe coil magnetic flux is induced in the coil(primary) and transfer to the secondary coilof the transformer due to the transformeraction. Transformer is an electro mechanicalstatic device which transforms electricalenergy from one coil to another withoutchanging its frequency.

Figure 6: Battery

Arduino Uno

Arduino is a single-board micro controllerintended to make the application of interactiveobjects or environments more accessible.Thehardware consists of an open-source hard-ware board designed aroundan 8-bit AtmelAVR microcontroller, or a 32-bit Atmel ARM.Current models feature an USB interface, 6

analogue input pins, as well as 14 digital I/Opins which allow to attach various extensionboards.

It is a microcontroller board based on theATmega328. It has 14 digital input/output pins(of which 6 can be used as PWM outputs), 6analogue inputs, a 16 MHz crystal oscillator,a USB connection, a power jack, an ICSPheader, and a reset button. It contains every-thing needed to support the microcontroller.

It is simply connected to a computer witha USB cable or powered with an AC-to-DCadapter or battery to get started. The Unodiffers from all preceding boards in that it doesnot use the FTDI USB-to-serial driver chip.Instead, it features the Atmega 8U2 progra-mmed as a USB-to-serial converter.

Figure 7: Arduino-Uno

Technical Specifications

MODEL CALCULATIONS

Chasis

Weight of the chassis = 2kg

Speed of the drive motors = 300 rpm

Diameter of the wheel = 6.8 cm

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We have,

Power required to drive the chassis (P) = F*V

And we know F = M*G

= 2*9.81

=19.62

Where, F= Force

V = Velocity = (π*d*n)/60

M= Mass

G= Acceleration due to gravity

Velocity 'V' = (π*0.068*300)/60

=1.068 m/sec

Power ‘P’ = F*V

= 19.62*1.068

= 20.96 W

Hence power required to drive the Chassis =20.95W

Wheel Motor

Speed of the drive motor = 300 rpm

We have,

Torque (T) = F*R

Where,

F = Force =M*G

R=Perpendicular distance =0.034

Therefore,

Torque ‘T’ = F*R

=1*9.81*0.034

=0.33 N-m

Power Obtained from the Wheel Motor

= (2*π*N*T)/60

=(2*π*30*0.33)/60

= 10.46 W

Hence Power Obtained from the

1 wheel motor = 10.46 W

Therefore power obtained from the

2 wheel motors = 2.092 W

Cutter Specifications

Speed of the Cutter Motor= 12000 rpm

Diameterof the Cutter Shaft= 9cm=0.09m

Torque (T) = F*r

Where,

r = Perpendicular distance to cutter axis =0.045

Therefore, Torque 'T' = 0.275*0.045

=0.0124 N-M

Power required to run the cutter Motor=(2*π*N*T)/60

= (2*π*12000*0.0124)/60

= 15.6 W

Hence, Power required to run the cutter Mo-tor = 15.6 W

Battery Specifications

Voltage of the battery ‘v’ = 12V

Current obtained from battery ‘i’ = 1.3 A

Power obtained from the battery = v*i

= 12*1.3= 15.6 W

Table 4: Technical Specifications

Domain

Micro Controller

Communication Device

Transmitter

Receiver

Battery

Rechargable Battery

Cutter Motor

Driver Motor

Chassis equipped withgrass cutter, Wirelesscommunication

AT89C52

DTMF Decoder

Mobile phone

Mobile phone

9V

12v 1.3AH

12000 rpm, Torque less

200 rpm, 5 kg Torque

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Hence, Power obtained from the

battery = 15.6W

DESIGN PRINCIPLE

The objective of this paper, is to control therobot by a mobilephone (as transmitter) thatmakes call to the mobilephone (asreceiver)attached to the robot. Now after answeringthe call, and in the course of the call, if anybutton is pressed control corres pondingtothebutton pressed is heard at the other endof the call. This tone is called dual tone multifrequency tone (DTMF) robot receives thisDTMF tone with the help of phones tacked inthe robot.

The received tone is processed by the89S52 micro controller with the help of DTMFdecoder MT8870 the decoder decodes theDTMF tone into its equivalent binary digit andthis binary number is send to the microcontroller, the micro controller is pre progra-mmed to take a decision for any give inputand outputs its decision to motor drivers inorder to drive the motors for forward orbackward motion or a turn.

So this simple robotic project does notrequire the construction of receiver andtransmitter units. DTMF signaling is used fortelephone signaling over the line in the voicefrequency band to the call switching center.The version of DTMF used for telephonedialing the mobile that makes a call to themobile phones tacked in the robot acts as aremote is known as touch tone. DTMFassigns a specific frequency (consisting oftwo Separate tones) to each keys that it caneasily be identified by the electronic circuit.

Figure 8: Module Design

Module Block Diagram

The signal generated by the DTMF decoderis the direct algebraic submission, in realtimeof the amplitudes of two sine (cosine) wavesof different frequencies, i.e., pressing 5 willsend a tone made by adding 1336Hz and 770Hz to the other end of the mobile.

The detected application by the DTMFencoder in ther over section is interface tothe personal computer through the DTMFdecoder and micro controller. so the DTMFencoding and decoding is used for thetransmission and receiving of datarespectively.

Figure 9: Rover Controlling Section

Operation

The operation of transmitter is done using aDTMF decoder, an Arduino Uno and L293DMotor Driver. The transmitter section is rover

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which was controlled by the mobile and it isarranged with certain applications attachedthrough the encoder and Arduino Circuit. Thecontrolled and the desired path are followedby using controller and transmitted usingtransmitter and is furthered operatedaccordingly if any unwanted material isdetected in its surroundings while it moves.

The designed lawn mower can move infour directions forward, backward, left andright. The directions are controlled by theDTMF decoder and the pre programmedArduino and the grass is cut along with themoment of the rover along the desired pathin the lawn. The technique we used here isDTMF technique for the controlling of therover, i.e. we know that each key in the mobilekey pad issum of two frequencies that iscolumn and row frequencies so each key haddifferent frequency. By using DTMF decoderwe can convert the frequency in to thatparticular binary number. Initially the roverconsist a mobile connected with headset. Themobile headset is connected to the DTMFdecoder input. Here the mobile act as areceiver to give a moment for ther over in arequired direction. Initially that is kept in autoanswer mode. By making the call to mobilewhich was attached to the rover from anyother mobile (transmitter) the call was attemp-ted automatically because of the auto answe-ring facility. Now if we press any key in themobile (transmitter) the DTMF decoderdecodes that frequency into its binary form.The out put depends upon the input appliedto it that is the output of the DTMF decoder.The Arduino gives the output based on a preprogrammed logic given to it. The code iswritten in such a way that it enables the

motors to move the rover in required directionand performs the grass cutting operation.(P Raghavendra Prasad and K SusramRahul, 2008).

The output current from the arduino circuitis about 10 mA which is not sufficient todrive the motors. So here L293D, a currentdriver is used. The current driver serves thepurpose by increasing the current to about600m A which is sufficient enough to drivethe motors. An encoder is also attached tothe rover, which is used to transmit the datarelated to the applications provided at thereover. All the outputs of applications are conn-ected to the encoder which transmits this datato the receiver section there by providing usthe required information regarding the envi-ronmental round the rover and the grasscutter.

Figure 10: Circuit

Applicationsof the Circuits

The rover we designed is an applicationthat can detect the presence of the motion,temperature, water and smoke when therover proposed to move in the desired direc-tion. All the above application circuits des-cribed below.

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• Motion Detector

• Smoke Detector

• Temperature Detector

• Water Detector

CONCLUSION

The advantage sex plained earlier in thischapter justify the significance of a mobilebased robotic arm. The application are as areal so vast with the simplest of modifications.Since all we need is a mobile call establish-ment to instruct the robot due to the cellphone’s un ending and cheap availability, thisis highly feasible. Thesignals received at therobot’s mobile are decoded with DTMFdecoder which is easy touse. No heavymotors are employed in the making of therobot, and thus it becomes very light weight.The level of sophistication is quite low andhence its working is user friendly.

This method is having good expectedresults. Thus the proposal should be consi-dered for the most important system for thesafety the costliest human life and the nationproperty. Since this robot is highly flexibleadding components to facilitate applicationspecific working yields a robot that has highuse in vast areas. This project can also besubjected to standardization and hence hasa good future scope.

REFERENCES

1. Passmore, Everett G et al. (1869),“Improvement in Lawn-Mowers”,published 23 February 1869, issued 28January 1879; For a copy, see GooglePatents copy (http://www.google.com/patents Autonomous Lawnmower Controlby Cameron Morland US RE 8560.

3. The Hall & Duck Trust et al.: Lawn MowerHistory Part 2" Retrieved 2011-04-23.

5. Costilla V and Bishai D M (2006),“Medical Researchers et al., 80,000Injuries a Year Attributed to MowerAccidents Landscape Management”.

6. Kinnander Ola et al. (2012), “Rise of theLawn-Cutting Machines”

7. Cheryl Springfels et al. (2011), “Pollutionfrom-gasoline-powered Lawnmowers”

8. Hollis, Scott. “Cordless electric lawnmowers: these battery-poweredmachines are clean, quiet and easy tomaintain”. Mother Earth News 209 (April-May 2005): 67(4). General ReferenceCentre Gold. Gale. Fairfax County PublicLibrary. 7 Apr. 2009.

9. DMOZ - Business: Consumer Goods andServices: Home and Garden: Lawn andGarden: Tools and Equipment: PowerTools

10. P Raghavendra Prasad and K SusramRahul et al. (2008), “Cell phone-OperatedLand Rover”, www.efymag.com

mobile operated lawnmower - ijmerr · all the above systems are controlled by the micro controller....

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