Car Park Report

Automatic Car Parking System

Chapter 1

Introduction

1


INTRODUCTION

Due to tremendous advancement in technology the prices of vehicles are

now economical to have it. But in comparison with this in cities there is shortage

of parking zones and because of this every body tries to park his vehicle properly,

which creates chaos at parking place. Therefore in today’s fast growing

technological world, regulation of parking is very important issue. With the

growing number of vehicles and the consequent shortage of parking space, there is

haphazard and totally unregulated parking of vehicles all over. The situation calls

out for an automated parking system that not only regulates parking in given area

but also keeps manual control to a bare minimum.

To cater to the need, here we present a miniature model of an automated

car parking system that regulates number of cars that can be parked in an area at

any given time based on the parking space availability. The entry and exit of

vehicles are facilitated using totally automated gate. Status signals indicate

whether space is currently available in the parking lot, and whether a car is

currently in the process of entering or leaving the parking space. Our system also

guides the driver by indicating which parking slot is vacant at any given time.

This feature saves the time of parking and also fuel.

After the initial installation, the system requires no manual control.

Everything, right from maintaining the count of vehicles to opening and closing

the gate, is automatically controlled. As the circuit uses low cost easily available

discrete ICs, it is cost effective.

2


Chapter 2

Block Diagram Description

3


BLOCK DIAGRAM DESCRIPTION

Figure 1 shows the block diagram of Automated Car Parking System. The

system consists of transmitter, receiver and demultiplexer, up-counter, down-

counter and display sections.

The transmitter section comprises two infrared transmitters (IR1 TX1 and

IR2 TX2), which transmit infrared beams as shown in figure 2. These light

becomes are incident on the corresponding infrared receiver modules (IR3 RX1

and IR4 RX2), which produce an output of 0 volt if the beam is received

uninterrupted and +5 volt if the beam is interrupted by a car.

Whenever a car enters the parking area, it interrupts the infrared beams in

a definite sequence. This sequence is given to the up-count sequence detector,

which generates a high output only if the correct sequence has been detected.

Similarly, when the car leaves the parking area, it generates a fixed sequence,

which is given to the down-count sequence detector. The down-count sequence

detector generates a high output only if the correct sequence is produced by

exiting car.

The outputs of the up-count, down-count blocks are given to the display

section. The display sections as a counter a 7-segment display along with driver

IC to display the count. Depending on the sequence detector that generates an

actuating signal, the count is either incremented or decremented. The display

section consists of status signals, which include:

1. A yellow signal to indicate that a car is currently in the processing of

entering or leaving the parking space.

2. A green signal is indicate that the parking lot has not reached its maximum

capacity, and that space is available the parking of a car in the parking

area.

3. A red signal to indicate that the parking space is full. The activation of this

signal coincides with the disabling of the green signal, and is a companied

by the disabling (closing) of the gate for vehicles trying to enter the

parking lot.

4


Fig.1 Block diagram of automated car parking

5


Chapter 3

System Overview

6


SYSTEM OVERVIEW

A gate has been provided at the entering of the parking space, which opens

on the arrival or departure of a car.

A display section has been provided, which consists of status signals and a

display showing the number of car present in the parking space at any point of

time.

A display section also provides the information regarding the vacancy of

parking slot by glowing the corresponding LED this assist the driver while

driving.

After the maximum numbers of cars have entered the parking space, the

gate is automatically disabled (closed) for vehicles seeking entry into the parking

lot.

A logic circuit distinguishes between the cars and persons / two wheelers,

so that persons and two wheelers are not included in the count of cars.

7


Chapter 4

Circuit Operation

8


CIRCUIT OPERATION

The automated car parking circuit as shown in figure 2 and figure 3. The

circuit primarily uses two NE555 timer ICs, four 74LS74 D flip-flop, 74155 2: 4

decoder, up/down binary counter 74193, 7-segment display driver L293D. In

addition, the circuit uses six TSOP 1738 infrared receiver modules, six infrared

transmitting LEDs, 7-segment display and green, red and yellow LEDs, along

with three-push-to-on switches.

For easy understanding the circuit, let’s divide the circuit into the

following four basic sections:

1. Sensor

2. Sequence detector

3. Counter and display

4. Gate control

5. Parking Slot indicator

The sensor section:

This section senses the movement of objects and transfers that information

to IC1 in the main circuit. The sensor section can be further divided into the

transmitter section and the receiver section. The prominent component used in the

design of the transmitter and receiver sections is the IR receiver module TSOP

1738. This is a highly selective receiver, which comprises a photo detector and a

preamplifier with IR filter in a single package to provide demodulated output. It

works efficiently with 1kHz modulation of 38 kHz bursts. This feature of the

receiver determines the composition of the transmitted signal.

For generating approximately 38kHz frequency carrier signal modulated

by a 1kHz square wave, we use too NE555 timer ICs in astable mode in the

transmitter section. One NE555 timer (IC 12) is designed to produce a square

wave of 1kHz with 50% duty cycle, while the second timer (IC 13) is designed to

produce a square wave of 38kHz with 50% duty cycle. In the order to modulate

the 38 kHz wave, output pin 3 of the first NE555 (IC 13). The final output of the

9


cascaded arrangement is given to a pair of IR LEDs through current-limiting

resistor R5, which prevents the IR LED from getting heated and thus damaged.

Fig.2: Circuit Diagram of IR transmitter part

The receiver section consists of two identical receiver circuits, using one

infrared receiver TSOP 1738 each. The output of this receiver is open-collector

type, and hence requires a pull-up resistor, whose value must be much greater than

10k. A 4.7F electrolytic capacitor must be connected between the supply and

ground for this receiver to minimize the interference of spurious signals in the

operation of the receiver.

When the signal is received correctly, the original 1kHz square wave

signal is obtained at the output of the receiver. In the absence of the signal,

however, a +5V DC level is obtained. Since the ICs in the following blocks are of

TTL family, the receiver must be TTL compatible.

The +5V DC level occasionally drops to 0V, even when the signal strength

is quite low, due to the high sensitivity of the receiver. This may lead to false

triggering of the circuit, which must be eliminated. For this, a 22F electrolytic

capacitor is connected between the output of the receiver and ground. This

capacitor bypasses the square wave to ground and holds the DC value of the signal

(which is 0V) in the normal state and +5V when the signal is blocked. In place of

this capacitor, you may also use any capacitor of comparable value.

10


The output of the sensor section goes to the sequence detection section.

11


Fig. 3 : Circuit Diagram of Automated car parking system

12


The sequence detection section:

This section is the heart of the entire system. It consists of a 2:4 decoder and

flip-flops, which are used for the sequence detection. The 74155 dual 2:4 decoder

IC1 receives its select signals at pins 13(A) and 3(B) (for one of the decoders)

from receivers RX1 and RX2, respectively. The other decoder is not used. The

output lines of the enabled decoder are active low.

For convenience, the receiver before the entrance to the gate is connected to

the pin 13 of the IC1. In default state, each receiver is active and inputs 0 to the

decoder, making the Y0 output line low.

When the first sensor is blocked, the Y1 line goes low. The low going Y2 line

indicates that only the second sensor is blocked. A low Y3 line indicates that both

signals have been blocked. Refer truth table of IC1 74155 given in table 1. The

four output lines act as decoding and control signals for the remaining circuits.

TABLE 1: Truth table of 74155 (IC1)

Address/ inputs Enable Outputs

Pin 13

(A)

Pin 3

(B)

Pin 1

E1

Pin 2

E1

Pint 7

1Y0

Pin 6

1Y1

Pin 5

1Y2

Pin 4

1Y3

0 0 H L L H H H

1 0 H L H L H H

1 1 H L H H H L

0 1 H L H H L H

The sequence detection logic circuit consists of three flip-flops for detecting

incoming as well as out going vehicles. The Y0 line is connected to the clear pins

of all the flip-flops, which gives 0 at their respective outputs. A vehicle entering

the parking area must interrupt the first sensor (before entrance), then both

sensors, and finally just the second sensor (after entrance). Thus it must generate

states 1 0, 1 1, and 0 1 necessarily in that sequence.

For identifying the states and the order in which they occur, we give the

Y2, Y3 and Y1 lines after logical inversion to the clock inputs of three successive

flip-flops, respectively. A VCC signal is input to the first flip-flop, while each

subsequent input is the output of the previous flip-flop. The logic states of the

13


three decoded output lines are inverted because these are active low, while the

74LS74 D flip-flops are triggered by a rising edge of the clock signal.

Only the proper sequence of logic states will cause a high logic at the

output of the third flip-flop. Any other sequence will not allowed the transfer of

the high signal through the series of flip-flops. The output of the third flip-flop is

given to the counter and display section, which increments the count. Thus when a

vehicle enters the parking area, the Y0 signal clears all the flip-flops, and this very

instant, the count is incremented.

An identical circuit is used for detecting a vehicle leaving the parking area.

In this case, however, the states generated by the vehicle are 0 1, 1 1, and 1 0,

necessarily in that order. Hence the clock signals for the three successive flip-

flops are derived from Y1, Y3 and Y2 line, respectively.

The working of this circuit is identical to the one for detecting the vehicle

entering the parking area. In this case the final D flip-flop output is given to the

counter and display section for decrementing the count. This occurs at he instant

when the outputs of the flip-flop are cleared by the low going Y0 signal

(explained in the counter and display section).

The counter and display section:

This section consists of up/down counter IC74193, BCD to 7-segment

decoder, display driver IC4511 (to drive a common cathode 7-segment display),

and three LEDs (red, yellow and green).

The counter IC74193 is capable of handling up as well as down counts, if

configured for the same. The count is incremented by one when a rising edge is

encountered on the up pin (pin 5) and decremented by one when a rising edge is

encountered on the down pin (pin4). In our circuit, the former occurs when the

vehicle has entered in the parking area and line Y0 clears the output of the final

flip-flop, causing a transition from the high to low logic state, which, when passed

through an inverter, provides a rising edge. The count decrements in the same

fashion when the flip-flops in question are those used for detecting the vehicle

leaving the parking area.

The preset data pins of the counter IC are connected to VCC, while the

load data pin is connected to one end of a push to on switch whose other pin is

14


grounded. Such an arrangement can be used to reset the counter, and consequently

all drivers and display unit in the circuit. The four output lines of up/ down

counter (74193) are fed to the corresponding pins in the decoder or the driver

4511 (IC9). The active high outputs of the decoder are connected to their

corresponding pins in the 7-segment common-cathode display.

The MSB and LSB lines of the outputs of the counter IC10 are ANDed

using gates N7 and N8. The output from gate 8 is fed to the anode of the red LED,

which indicates that nine vehicles are present in the parking area and there is no

further space. This happens because the output of the binary 9 on the lines makes

the extreme lines high, which gives a high at the otherwise-low anode of the red

LED, thus turning it on.

The same signal after inversion is given to the anode of the green LED,

which indicates the availability of space for at least one vehicle in the parking

area.

The yellow LED indicates that a vehicle is either entering or leaving the

parking area. Hence, this LED must be on when at least one of the sensors is being

cut. For this reason, the Y0 line of the decoder is given at the anode of the LED.

When no signal is being cut, the Y0 line is low, keeping the LED off. But as soon

as any one of the signals is cut, the Y0 line goes high, turning the yellow LED on.

The LED indication for the various situations is depicted in table 2.

TABLE 2: LED Indications

LED Indication

Yellow Car is in the process of parking

Red No vacancy

Green Parking space available

The gate control section:

The gate control section consists of IC5, IC4 and IC11, which provide the

appropriate logic used for controlling operation of the gate/barrier.

Assume that the lower position of the barrier is the default position. Now

whenever the input to motor driver IC11 is 1 0, it causes the motor to rotate,

thereby causing the barrier to move such that it opens the entrance.

15


Similarly, when the input to motor driver is 0 1, the motor rotates in the

opposite direction to lower the barrier, thereby closing the gate. When the input to

the motor driver is 0 0, the motor does not rotate.

When the car as entered the parking area completely, the input to the IC11

is 0 1, causing the motor to rotate such that the gate begins to close till it pushes

the lower switch at which point it stops moving.

Thus, the movement of the gate is automatically controlled on the arrival

or departure of a car. Table 3 gives clear picture of the working of the gate control

section.

TABLE 3: Truth table of 7474 (IC5)

Pin 2

(D1)

Pin 13

(D2)

Pin 5

Q1

Pin 9

Q2

State

0 1 0 0 Default. Lower switch S2 closed.

1 0 1 0First sensor cut. The gate starts opening

and lower switch S2 is released.

1 0 1 0 The gate keeps opening.

1 0 0 0The upper switch S1 closed. The gate

stops opening.

0 1 0 1

Car completely enters the parking area.

The gate starts closing and upper switch

S1 is released.

0 1 0 1 The gate continues to close.

0 1 0 0The gate pushes lower switch S2 and

stops moving. Back to default states.

In order to disable the gate from opening for a vehicle entering the parking

area after the count of the 9, we use a simple combinational logic circuit consists

of NAND and OR gates, whose output is given to enable in 1 of the L293D motor

driver (IC11). In normal condition, the output of this logic circuit is high, enabling

IC11. When the maximum count of the 9 is reached, the output of the logic circuit

becomes low, thereby disabling the motor and keeping the gate closed for all

vehicles seeking entry to the parking area.

16


However, when a vehicle wishes to leave the area IC11 gets enabled, thus

opening the gate. The output current capability per channel of L293D

approximately 600mA. The truth table of L293D is given in table 4.

TABLE 4: Truth Table of L293D

Input Enable * Output

H H H

L H I

H L Z

L L Z

Note:1. Z is high impedance output.2. * For channel under consideration.

Parking Slot Indicator:

This section provides the indication of vacant parking slot at any given

time based on the parking slot availability. This consists of infrared transmitter

and infrared receiver as shown in figure 4 and figure 5. The identical circuit is

placed in the each parking slot so that it indicates whether the car is present in that

slot or not.

Fig. 4 : IR Transmitter

17


The circuit diagram IR transmitter of Parking Slot indicator is shown in

figure 4. This is built around timer IC555, which is used as an astable

multivibrator to generate around 38kHz frequency. The timer output is fed to

transistor T1, which drives IR LED. Note that IR LED1 must be properly oriented

towards the IR sensor module of the receiver circuit. Its transmitting wavelength

of 900 to 1100m lies in the peak receptivity range of the TSOP1738 receiver

module. We have used two identical circuits are used for the two infrared

transmitters.

Fig. 5: IR Receiver

The receiver section consists one infrared receiver TSOP 1738. The output

of this receiver is open-collector type, and hence requires a pull-up resistor, whose

value must be much greater than 10k. A 4.7F electrolytic capacitor must be

connected between the supply and ground for this receiver to minimize the

interference of spurious signals in the operation of the receiver.

When the signal is received correctly, the original square wave signal is

obtained at the output of the receiver. In the absence of the signal, however, a +5V

DC level is obtained. Since the ICs in the following blocks are of TTL family, the

receiver must be TTL compatible.

18


The +5V DC level occasionally drops to 0V, even when the signal strength

is quite low, due to the high sensitivity of the receiver. This may lead to false

triggering of the circuit, which must be eliminated. For this, a 22F electrolytic

capacitor is connected between the output of the receiver and ground. This

capacitor bypasses the square wave to ground and holds the DC value of the signal

(which is 0V) in the normal state and +5V when the signal is blocked. In place of

this capacitor, you may also use any capacitor of comparable value.

The output of IR receiver is given to the LED, which indicates the current

status of the parking slot. IR receiver gives the 5V when any vehicle interrupts the

infrared beam that means LED will glow when there is car in the parking and

LED will not glow when parking slot is vacant.

19


Chapter 5

Preparation of

PCB

20


PREPARATION OF PRINTED CIRCUIT BOARD

The process of preparation of Printed Circuit Board (PCB) is explained as follows:

1. The artwork is prepared of the circuit using software viz. ‘ORCAD 9.1’.

2. Then a negative of this artwork is prepared for further process.

3. Required size of PCB is marked on glass epoxy PCB clad with marker.

4. Using shearing machine the marked portion of glass epoxy PCB clad is

cut.

5. The glass epoxy PCB clad is cleaned using steel wool care should be

taken, so that one cleans it only in one particular direction.

6. Now apply photo resist chemical. This chemical can also be applied by

machine, but we have applied it manually, so as to have a thin even coat of

photo resist chemical over the clad.

7. After the clad has dried off, it is superimposed by the negative and set into

the ultraviolet exposure machine. Care should be taken while

superimposing the negative.

8. Now ‘ON’ the UV exposure for 2 minutes let the clad get exposed to UV

rays wherever required.

9. Further developing is done using photo resist developer i.e. mild

trichloroethylene.

10. Apply blue color dye and then wash it under flowing water and then let it

dry.

11. The final chemical process is etching. There are three etching chemicals

generally been used for PCB etching viz. Ferric chloride, Ammonium

persulphate and chloric acid. Here we have used Ferric Chloride for

etching process.

12. Finally holes are drilled at the islands of components, lead connections and

for wire connections.

21


Chapter 6

Applications&

Limitations

22


APPLICATIONS AND LIMITATIONS

Applications:

Some of the application is discussed briefly as follows.

Underground Parking

Company Parking

Pay-and-Park scheme.

Limitations:

1. There should be a battery back up for knowing exact number of car

passed.

2. This project caters for 9 cars only. It applies for cars only (not for

cycles / scooters).

3. Proper orientation of receiver and transmitter is very important.

4. The distance between the two transmitted beams should be less

than the length of the longest car to be parked.

23


Chapter 7

Conclusion

CONCLUSION

24


Due to tremendous advancement in technology the prices of vehicles are

now economical to have it. But in comparison with this in cities there is shortage

of parking zones and because of this every body tries to park his vehicle properly,

which creates chaos at parking place. Therefore in today’s fast growing

technological world, regulation of parking is very important issue.

Our project caters this problem by automating parking system so that it

regulates number of cars can be parked in an area. After the initial installation, the

system requires no manual control. Everything, right from maintaining the count

of vehicles to opening and closing the gate, is automatically controlled. As the

circuit uses low cost easily available discrete ICs, it is cost effective.

Future scope of our project is overcome the limitations of i.e. it caters only

nine cars. This can by easily modified by adding extra circuitry to the current

system. By cascading counter and display section, we are able to regulate the 99

vehicles. It is also possible to use microcontroller instead discrete digital IC.

25


Chapter 8

Component List

26


COMPONENT LIST

1. Semiconductors

Component Name Specification Quantity

IC1 74LS155 dual 2:4 decoder ONE (1)

IC2 7404 hex inverter ONE (1)

IC3 7400 NAND gate ONE (1)

IC4 7432 OR gate ONE (1)

IC5 to IC8 74LS74 dual ‘D’ flip-flop FOUR (4)

IC9 4511 7-segment trigger ONE (1)

IC1074193 4-bit up/down

counterONE (1)

IC11L293D push-pull 4-channel

driver without motor ONE (1)

IC12, IC13 NE555 timer TWO (2)

D1, D2 1N4148 diode TWO (2)

LED1 5mm yellow LED ONE (1)

LED2 5mm red LED ONE (1)

LED3 5mm green LED ONE (1)

IR1, IR2 Infrared transmitter LED TWO (2)

IR3, IR4Infrared receiver module

(TSOP1738) TWO (2)

DIS1LTS-543 common cathode

7-segment displayONE (1)

27


2. Resistors (all ¼ watt, +/-5% carbon unless stated otherwise):Component Name Specification Quantity

R1, R2 3.3Kohm TWO (2)

R3, R4 1.8Kohm TWO (2)

R5, R6, R8 100Kohm THREE (3)

R7, R9 1Mohm TWO (2)

R10 to R19 330Kohm TEN (10)

3.Capacitors


C1 0.22 F, ceramic disk ONE (1)

C2 to C4 0.01 F, ceramic disk THREE (3)

C5, C7 0.47 F, 16V electrolytic TWO (2)

C6, C8 22 F, 16V electrolytic TWO (2)

4. Miscellaneous


S1 to S3 Push-to-on tactile switch THREE (3)

IC Bases 8-pin bases TWO (2)

IC Bases 14-pin bases SEVEN (7)

IC Bases 16-pin bases FOUR (4)

Power supply 5V, 1A regulated ONE (1)

Flexible wire

D.C. MotorMotor up to 600mA

output convert capabilityONE (1)

28


Chapter 9

Bibliography

29


BIBLIOGRAPHY

1. Basic Electronics Principle by Malvino

2. Digital Electronics by R.P Jain

3. Electronics Project Section, Electronics For You

4. TTL Data Manual

5. Principles of Basic Electronics by V. K. Mehata

6. www.datasheetcatalog.com

30


Chapter 10

Datasheets

31

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