design and fabrication of tire pressure management system

8/18/2019 Design and Fabrication of Tire Pressure Management System

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DESIGN AND FABRICATION OF TIRE

PRESSURE MANAGEMENTSYSTEM

PROJECT REPORT

Submitted by

KARTHICK.S (730713114060)

A.SATHISKUMAR (730713114323)

In partial fulfillment for the award of the degree

Of

BACHEOR OF ENGINEERING

In

MECHANICA ENGINEERING

DEPARTMENT OF MECHANICA ENGINEERING

E!CE COEGE OF ENGINEERING AND TECHNOOGY

PAAKAPAAYAM

ANNA UNI"ERSITY# CHENNAI$600 02%

APRI 2016


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ANNA UNI"ERSITY# CHENNAI$ 600 02%

BONAFIDE CERTIFICATE

Certified that this project report “DESIGN AND FABRICATION OF TIRE PRESSURE

MANAGEMENT SYSTEM” is a bonafide work of

KARTHICK.S (730713114060)

A.SATHISKUMAR (730713114323)

Who carried out the project work under my supervision.

SIGNATURE SIGNATURE

D&.M.MURUGAN'M.E.'P.D.'

M&.N."ENKATACHAAM'M.E.'

FIE.' PGDCA.'(P.D).'

HEAD OF DEPARTMENT SUPER"ISOR

epartment of !echanical "ngineering# $ssociate %rofessor&!"C'

ept.#

"(cel College of "ngineering and "(cel College of "ngineering and

)echnology# )echnology#

%allakapalayam. %allakapalayam.

S*+,--/ & - &- 5,5 5 / 8.......................................

INTERNA E!AMINER E!TERNA E!AMINER


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ABSTRACT

Improper tire pressure is a safety issue that is often overlooked or ignored. $ drop in tire

pressure by just a few pounds per s*uare inch +%,I- can result in the reduction of gas mileage#

tire life# safety# and vehicle performance. )o address this problem# an automated system that

will alleviate the need for actively maintaining tire pressure was designed. )his report

documents the design process for an onboard tire pressure management system +)%!,-

consisting of a centralied processor# air compressor# air control valves and rotary seals near

each wheel. )he

/otary seals allow the air line to transfer from the chassis to the wheel without entanglement.

)he system takes periodic tire pressure readings and makes adjustments according to the

desired pressure setting. )%!, comes with several pre0defined tire pressure settings and allows

the user to enter their own pressure setting if needed. %ressure settings# current pressures and

flat&leak notifications are all displayed on a li*uid crystal display +1C- located in the dash.

)his system

Will take the maintenance out of upholding tire pressure and increase tire life# fuel efficiency

and vehicle safety and performance.


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iACKNO9EDGEMENT

We would like to e(press our sincere thanks to our honorable chairman P&.D&.A.K.N-:8M.C+.' MBA.' M.P,.' P.D.' FTA.' PHF.' and all the members of ,ri /engaswamy#

"ducational )rust.

We e(press our whole hearted thanks to D&.E.P8,:;+


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ii

CONTENT

CHAPTER

NO.

TITE PAGE NO.

$bstract i2 Introduction 23 %roblem ,tatements 34 ,cope 45 /e*uirement ,pecification 5

5.2 )echnical /e*uirements 55.3Weidhting 6actors 75.4 /otary ,eal $ssembly 7 5.4.2 8eometric imension $nd )olerance 7 5.4.3 !anufacturing 95.5 $ir %ressure !onitoring ,ystem Of :ehicle

)ire $nd Identification !ethod Of :ehicle )ire

;y Wei $nd 'ong ling

9

5.< )ire %ressure !onitoring +)%!- ,ystem ;y

1aurens $nd =ill

>

5.7 "lectrical esign > 5.7.2 'ardware > 5.7.3 ,oftware 22 5.7.4 ?ser Interface 24

< irect )pms 8eneral Operation Of )raditional

)pms

2<

Cost of the project 32A ;ibliography 33

2B Image of the project 34iii

TABE OF THE FIGURE

FIGURE TITE PAGE NO

2 $ssembly Of /otary ,eal 9


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3 6unctional ecomposition 22

4 !ain screen 24

5 ,chematic diagram of general operation of a

direct )%!,

27

< ;loke diagram for pressure monitoring system 2>

iv

CHAPTER 1

INTRODUCTION

)he majority of automobile drivers do not ade*uately maintain their tire pressure# even

though they lose appro(imately one to two pounds per s*uare inch +%,I- of air pressure a


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month. ?nderinflated tires cause a greater contact surface area with the road# resulting in higher

friction between the road and tire. )his significantly decreases tire life and fuel economy.

:ehicle handling characteristics are also adversely affected due to low tire pressures. ,topping

distances increase and the driver e(periences a loss of steering precision and cornering stability

With all these undesirable effects# proper tire pressure should be of greater concern.

)he ational 'ighway )raffic ,afety $dministration +'),$- statistics show that 77B

fatalities and 44#BBB injuries occur every year as a result of low0tire pressure0related crashes.

)he main reasons for incorrectly inflated tires include vehicle owners not knowing proper tire

pressures for certain conditions# difficulty finding an air pump# lack of a pressure measuring

device# and a general lack of concern. )he /ubber !anufacturers $ssociation has estimated that

only about 2A percent of drivers properly check their tire pressure.

)hese facts show that a system is needed to maintain proper tire pressure for optimal

performance in a variety of driving conditions. )his report will discuss the design of a system

that makes pressure adjustments to the front and rear tires separately through the use of a user

control interface. )he system consists of a centralied air compressor# a reservoir storage tank#

and solenoid valves to control the direction of air flow.

2

CHAPTER 2

PROBEM STATEMENTS

)he first problem statement is the location of the system. )he transmitting and detection

unit will be located inside the tire. )he location of the system is crucial for safety aspect and

precision of the data that will be gained. )he second problem statement is the sie of the system


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which the sie of the transmitting and detection unit needs to be small enough if it were to

locate inside the tire. )he third is wire transmissionD when tire is rotating# the transmitting and

detection unit will be transposed. )ire identification might be miscorrelated and the information

displayed on the screen about the pressure and temperature as correlated with the tire is wrong.

)he fourth problem statement is sensor is using battery. )raditional direct )%!, re*uires

battery in each tire to power the sensor and the circuits# but the use of batteries raise potential

problems including limited life span# temperature0dependent capability# added weight

environmental concerns# and larger maintenance cost. )he fifth and the last problem statement

is self0generating power. In this project# self0generating power system is to be designed to

replace the batteryEs function as main power supply .

2

CHAPTER 3

SCOPE

)here are many ways to design and develop a )%!,. )his project re*uires e(tensive

research that might widen up the scope. 'ence# the projectEs scope needs to be defined first in

order for this project to reach its objectives. )ransmitting and detection unit could be installed


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outside the tire# but this will increases the risk of being damaged by e(ternal environment and

even get stolen. 'ence# the proper position of the unit would be inside the tire where the

measurement of the pressure value is directly obtained. In order to place the transmitting and

detection unit inside the tire# considerations of sie of the unit needs to be taken. )he sie

should be small enough to fit in inside the tire.

)here are many ways to achieve wireless transmission. ;ut this project will be dedicated

in using radio fre*uency method# where receiver and transmitter are needed. ,ensor is

integrated with the transmitting and detection unit# thus it re*uires power supply. )raditional

direct )%!, using battery as the solution but it has a few problems. 'ence# this project will

design a system that does not re*uire battery. One of the alternatives is by using pieoelectric

method. When stress or pressure is applied on the pieoelectric material# electric current will be

produced. )his current will be used to power the transmitting and detection unit.

3

CHAPTER 4RE?UIREMENT SPECIFICATION

)he driving force behind the tire pressure management system +)%!,- was to solve the

incorrect tire pressure situation. ,everal key objectives were set forth in order to design a

product which satisfies the problem and customerEs needs.


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4.1 TECHNICA RE?UIREMENTS

Ideally# the general re*uirement of )%!, was to maintain an automobileEs tire pressure

to the manufacturers suggested tire pressure +around 43 %,I-. ,ince pressure in the tire varies

with surface temperature# it was practical to maintain the pressure within 2 %,I of the desired

value. In conjunction with maintaining tire pressure# )%!, also needed to display the current

tire pressure of all four tires within F2 %,I of the desired value.

)%!, needed to have preset pressure settings for different operating conditions. 6or

pulling a heavy load out of an incline at slow speeds# crawling out of soft dirt# or maneuvering

through challenging terrain# a lower tire pressure is desired in order to ma(imie traction. On

the other hand# when traveling with no e(ternal vehicle loading# the tire manufacturerEs

recommended pressure setting needed to be used for optimal performance

and gas mileage. ,imilarly# when towing a heavier e(ternal load at average to higher speeds# a

slightly higher tire pressure was desired.

If none of the preset settings were satisfactory for the user# )%!, needed to have the

capability of setting the tire pressure between 2< and 5< %,I. In support of being user friendly

the system needed to be built to be automatic# re*uiring no user input. )he system also needed

to have the capability of inflating or deflating four 3> inch tires from 2< to 4B %,I within 23

minutes.6or safety and performance concerns# )%!, needed to be capable of notifying the user

of a flat or slow leak condition. When any tire was measured at a pressure of less than 2B %,I or

any tire is 3BG below the pressure of any other tire a warning for flat or possible leaks would be

displayed respectively. )his would allow the user an opportunity to have the tire serviced or

replaced before failure.

5

In order to avoid modification to the vehicles current electrical supply# the system needed

to be capable of operating off a 23 volt source. )able I reviews the tire pressure management

systemEs technical re*uirements# goal values# and how those values were verified.


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<4.2 9EIGHTING FACTORS

When three proposed solutions were drafted# with the capabilities to meet the technical

re*uirements# certain design criteria were weighted to help aide the prototype selection. It was

important that )%!, was user friendly. ,ince the primary customer for )%!, was the

automotive market# it was vital that the system would have a relatively high air flow rate# so the


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customer would not wait long periods of time between pressure alterations. $lthough noise was

a bigger concern for cars than trucks# )%!, would need to be relatively *uiet and present no

sound discomfort to the user.

ue to the potential for operating in many environments# it was important that )%!, had

the ability to be isolated from the environment. 6or instance# when a truck would be pulling a

boat out of the water from a launch ramp or driving in off road environments such as snow

mud# sand# dust# and rocks# )%!, would still need to function properly.

$nother criterion of importance was the budget of the system. )he prototype cost needed

to be no more than H3#BBB and production costs of the system needed to be less than H


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the a(le ring was built# it was pressed onto the a(le. 6or final assembly the seals were installed

to the /,$ housing using the recommend grease# from %arker !anufacturing# for proper

lubrication. )hen the housing slid onto the a(le and over the a(le ring. 6inally# all the wheelEs

components were placed in their perspective positions.

6ig 2 $ssembly of rotary seal

4.4 A,& P&::& M8,-&,8= S


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of low fre*uency +16- signal in 16 wake0up being disturbed in transmitting by the

electromagnetic noise in the automobile and essentially solves the disturbance problem.

4.% T,& P&::& M8,-&,8= (TPM) S


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of one conversion start signal. ?pon completion of all the measurements the !,%54B issued

another interrupt to notify the system the $C was done. $t the assertion of this interrupt the

system then evaluated the measurements and made the appropriate decisions.

)he $C within the !,%54B was a successive appro(imation register converter

+,$/-.)his meant that the input voltage was sampled to a capacitor array. )his sampling

produced transient currents that re*uired current to either be sourced to or from the $C input

pins. )his transient current could have created an error on the output of the pressure sensors if

the sensors were connected directly to the $C inputs. )he preferred method for driving a

,$/$C is with an operational amplifier +opamp- used to buffer the input.

)I produces many opamps# so picking one was a challenging task. %art of the challenge

was not just choosing one opamp of many# but finding the correct one to suit the needs of the

design. )he output of the pressure sensorsE aLwere in the range of B.< to 5.


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of eight arlington pair transistors that could run on up to


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,hown in fig. 3.

6ig 3 6unctional ecomposition

4.6.2 SOFT9ARE

)he !,%54B had the advantage of having many different interrupt modes that could be

programmed. 6or this reason an event style of coding was used for the system. ?sing one of the

internal timers of the !,%54B# an interrupt was set to happen every


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)his leak condition was not meant to determine of a tire was damaged# only toward the user that

a problem could have been present.

If neither of the two previous conditions were found# then the algorithm determined if the

system needed to adjust the pressure of any of the tires. )his determination was made based on

a moving average of each tire. $ total of 23> measurements was averaged and used to evaluate

what adjustments needed to be made. )his number of measurements gave a total time of 7.5

seconds. )his time was long enough that any impulses generated in the system# such as hitting

pot holes in the road# would be filtered out. )his filtering mechanism was one method used to

help increase the stability of the system.

uring adjustments of the tires# the averaging of the tire pressures was reduced to eight

data points. )his was done to ensure the pressure of each tire was not adjusted too far above or

below the target value. )he system was designed to be within F 2 %,I of the target value.

Once an adjustment was made and the tires were set to the correct pressures# the running

average was reset. It took another 7.5 seconds before any further adjustments would be made.

Once a decision for adjustment was made by the system a wait state was implemented. )he

implementation of the wait state was needed to ensure stability of the system. It was found that

the sensors would not take accurate readings of the pressures when air was flowing to or from

the tires. )his error was caused by the gradient of the pressure# from the high or low pressurereservoir to the tires. )he errors would cause e(treme overshoots and

?ndershoot within the system. )his created oscillation in the algorithm and the port that

drove the ?13>B4. )his oscillation was too fast for the solenoid valves to react to and so they

would not respond. )he wait state consisted of making an adjustment decision. )hen allowing

that decision to run for a fi(ed period of time. Once the time elapsed the adjustment was

discontinued and the air flow was stopped. $t this time the sensors were able to produce correct

readings. )he algorithm would them make new decisions once a new average was completed.

23

$nother event that took place within the system was the user supplying inputs through

the use of the keypad. $ key press on the key pad generated an interrupt signal to the system.

)he system then evaluated the input and acted accordingly.


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4.6.3 USER INTERFACE

)o provide a functional system# a well planned user interface needed to be designed. )his

interface consists of both a keypad and a li*uid crystal display +1C-. )hrough this setup# the

user can monitor the current pressure settings in each individual tire# manually change the

pressure# or change the pressure by selecting one of four presets.

)he main display shows four circles on the left hand side of the 1C with the pressure of

each tire written within the circle. $lso within the circles will be a reference to which tire

pressure it is displaying. )he codes are 6/# 61# //# and /1 for front right tire# front left tire#

rear right tire# and rear left tire respectively. On the right side# the target pressures for the front

and rear tires are displayed. If a flat or leak is detected# a warning will be displayed in the

bottom right corner of this screen. 6igure 4 shows this display.

6ig 4 !ain screen

If a user wishes to change the pressure by just selecting a new number# a new set of

screens will be shown. 6irst# the K key is entered# which takes the user to an a(le selection

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,creen. )his screen will display three options# both a(les# rear a(le# and front a(le. )he user

then presses which letter corresponds to their selection. )hen# the main screen is displayed. If

the user wishes to just type in a number without choosing an a(le# the last a(le selection will be

used.


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Once the user presses the first digit# another screen is displayed. On this screen the use

renters the desired pressure# which will appear on the display when they press the keys. Once

the correct pressure is shown# the K key is again pressed to confirm the change in pressure. )hen

the main screen will be displayed again# reflecting the changes.

)he second method of changing the tire pressure is by choosing a preset. If the user

presses the M key# a new screen will display a menu of presets including normal# highway

snow&ice# and off0road. )he user must press the letter corresponding to their selection. )hen the

display is returned to the main screen again with the new changes reflected.

With this user interface# the user has control of the system. )hey are able to make

changes to the system and view when these changes take effect. )hey should be able to easily

understand how the system is responding to the inputs. )his level of interaction should give the

user confidence of the systemEs functionality.

25

CHAPTER %

GENERA OPERATION OF TRADITIONA TPMS


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$n automobile tire pressure monitoring system and tire identification method includes a

transmitting and detection unit provided on each tire# as well as a receiving and display unit that

includes a receiving unit# a main control unit and a display unit. $ plug0in encoding memory is

plugged into the receiving and display unit. One fi(ed identification +I- code# which is the

same as that for the encoding memory# is provided for each transmitting and detection unit.

When the power is on# the receiving and display unit reads the I code in each plug0in

encoding memory plugged into the socket of the display unit# and saves the information on the

corresponding relationships between I codes saved in memories entire identity. )he receiving

and display unit reads the I codes in it# and determines whether these codes are identical with

those in the memories. If the signal is valid# the receiving and display unit compares the

corresponding relationships# determines which tire the detection unit is transmitting the signal#

and displays the information about pressure and temperature in corresponding display areas.

$s shown in 6igure 5# an automobile tire pressure monitoring system generally consists

of a transmitting and detection unit A3 and a receiving and display unit A2# which thereupon

comprises display unit A2B2# receiving unit A2B3 and receiving antenna A2B4.)he left side of

6igure 5 is a front sketch diagram of the display unit# i.e.# the screen that is displayed on the

automobile instrument panel. )he display unit A2AB2 of an ordinary automobile includes four

data display areas A2B22 that display the parameters of the four tires respectively. )he brokenlines in 6igure 5 represent the correlations between the display area A2B22 and the respective

tires.

2


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6ig 5,chematic diagram of general operation of a direct )%!,

,ourceN Wei and 'ongling 3BB<

)he operation process is as followsN )he sensor in the transmitting and detection unit A3converts variation of the tire pressure into electric parameters which vary accordingly to

electronic component induction. )hen# the electric parameters are processed by a !C? in the

transmitting and detection unit into digital code signals. $fter identification of the I of the

digital code signals in this unit +used to distinguish it from other units- is completed# these code

signals are transmitted via a carrier fre*uency by a transmitter. )he original data is recovered

after the radio signals are received and demodulated by the receiver antenna A2B4. )hen# after

being processed by the !C? of receiving and display unit# the data is displayed on the

corresponding tire data area of the userEs interface by the display screen installed in the vehicle

In this way# the driver can clearly know the pressure in each tire. When the received data shows

the pressure in the tire lower or higher than the set limit# the !C? will show an alarm icon on

27


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the display screen. )he driver can then take appropriate action for the tire according to the data

of tire pressure shown so as to ensure safe driving.

6i(ed encoding methodN )he correlation between I code in the !C? memory of the

receiving and display unit and the tire identification information is fi(ed at the factory. )he

same I code is also fi(ed in the !C? memory of the transmitting and detecting unit and is

marked on the surface of the transmitting and detection unit. uring the installation# the

transmitting and detection units are installed on the corresponding tires in accordance with the

marks and no change is allowed during application. )his method is *uite simple and its

shortcoming is that wrong installation is not allowed. Otherwise# identification confusion may

arise. !eanwhile# if a transmission unit is damaged# the user has to go to the manufacturer for

repair or replacement. )he transmitting and detecting units must be reinstalled in accordance

with their marked positions when the tires are rotated.

%.1 DIRECT TPMS

)his part will e(plain the present invention of direct )%!,. ;asic principle is still the

same but every invention uses different approach to realie the application. ,ome inventions

used different materials# and some used different circuit.

29


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6ig < ;loke diagram for pressure monitoring system

2>


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CHAPTER 6

AD"ANTAGES

It will used in monitoring the tire pressure in running condition.

It will used in all type of road conditions.

)his system used to control the tire friction. Circuit system is simple.

It will used in the aeronautical and automobiles industries.

It will use in increases the efficiency of vehicle.

DISAD"ANTAGE

)he e(perimental cost is high.

"(tra e*uipments are needed.

APPICATION.

It will used in all type of road conditions.

It will used in the aeronautical and automobiles industries.

It will use in increases the efficiency of vehicle.

2ACHAPTER 7

CONCUSION


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$n automated system was developed that will alleviate the need for actively maintaining

tire pressure. )he rotary seal assembly allows air to transfer from the chassis to the wheel. )he

system comes with several pre0defined tire pressure settings and allows the user to enter their

own pressure setting if needed. %ressure settings# current pressures and flat&leak notifications

are all displayed on an 1C located in the dash. )his system will take the maintenance out of

proper tire pressure resulting in increased tire life# fuel efficiency# vehicle safety and

performance.

3BCHAPTER @

COST OF THE PROJECT


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S.NO PAYING DETAIS AMOUNT

2 )ireiorn rodbearings 2>3B3 1athe works @ welding >3B4 %ressure valvetube 2>B

5 "lectronic circuit 22BB< 1abor cost 9BB

TOTA 4620

32

CHAPTER

REFERENCES

P2Q “=eep our )ires at %roper Inflation.” oran !anufacturing 11C.


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httpN&&www.doranmfg.com&industryRstudies.htm .

P3Q “:ehicle ,afety /esearch.” ational 'ighway )raffic ,afety $dministration.

httpN&&www.nhtsa.dot.gov&.

P4Q “)ire !aintenance and ,afety.” )he /ubber !anufacturers $ssociation.

httpN&&www.rma.org&.

P5Q 6ederal !otor :ehicle ,afety ,tandardsD )ire %ressure !onitoring ,ystemsD Controls and

isplays#” epartment of )ransportation and ational 'ighway )raffic ,afety $dministration#

full document available at www.nhtsa.dot.gov&cars&rules&rulings&)ire%res6inal&

P


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design and fabrication of tire pressure management system

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