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, whic which h creat creates es chao chaoss at park parkin ing g place place.. Ther Therefo efore re in toda today’ y’ss fast fast grow growin ing g technol technologi ogical cal world, world, regula regulatio tion n of parkin parking g is very very import important ant issue. issue. With 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 vehicl vehicles es are facilit facilitated ated using using totall totally y automa automated ted gate. gate. Status Status signal signalss indicat indicatee 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, downcounter 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 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. 9


VC C

R1

R3

3.3kOhm

7

1.8kOhm

4

8

RS T

VC C 7

DIS IC12

D1 R2 1N4148

6

THR

8

OU T

RS T

VC C

IC13 R4

1N4148

IR1

DI S

D2 3

3.3kOhm

6

TH R

R5 OU T

3

1.8kOhm

100

LM555CM 2

4

Ohm

LM555CM 2

TRI

TR I

A CO N

GN D

To

CO N

GN D

5

1

IC5 5

1

IR2

C1

C2

C3

C4

0.22uF

0.01uF

0.01uF

0.01uF

GN D

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 4.7 µ F 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 22 µ F 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 the sensor section goes to the sequence detection section.

10


Fig. 3 : Circuit Diagram of Automated car parking system

11


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 Pin 13 Pin 3 (A) 0 1 1 0

(B) 0 0 1 1

Enable Pin 1 Pin 2 E1 H H H H

Pint 7

E1 L L L L

1Y0 L H H H

Outputs Pin 6 Pin 5

Pin 4

1Y1 H L H H

1Y3 H H L H

1Y2 H H H L

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 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. 12


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 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 13


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 a t 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 Yellow Red Green

Indication Car is in the process of parking No vacancy 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. 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. 14


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

Pin 13

Pin 5

Pin 9

(D1) 0

(D2) 1

Q1 0

Q2 0

1

0

1

0

1

0

1

0

1

0

0

0

0

1

0

1

The gate starts closing and upper switch S1 is released. The gate continues to close. The gate pushes lower switch S2 and

0

1

0

1

0

1

0

0

State Default. Lower switch S2 closed. First sensor cut. The gate starts opening and lower switch S2 is released. The gate keeps opening. The upper switch S1 closed. The gate stops opening. Car completely enters the parking area.

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. 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 H

Enable * H

15

Output H


L H L

H L L

I Z 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. VCC +5V IR

R1

LED

1K 4

8

7 VR1

R2

6

3

555

20K 2

1K

IC1

1

T1 BC547

5

R3 22

C1 0.001uF

C2

ohm

0.01uF

Fig. 4 : IR Transmitter 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

16


module. We have used two identical circuits are used for the two infrared transmitters. VCC +5V

R1 100 ohm R2 1M

2

TSOP 1738

ohm

3 R3 330 ohm

1 C1

C2

4.7uF

22uF

16V

16V

LED1

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 4.7 µ F 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. 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 22 µ F 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

17


(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.

18


Chapter 5

Preparation of PCB

19


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.

20


Chapter 6

Applications &

Limitations

21


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.

22


Chapter 7

Conclusion

CONCLUSION 23


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.

24


Chapter 8

Component List

25


COMPONENT LIST

1. Semiconductors Component Name IC1 IC2 IC3 IC4 IC5 to IC8 IC9

IC10 IC11 IC12, IC13 D1, D2 LED1 LED2 LED3 IR1, IR2 IR3, IR4 DIS1

Specification 74LS155 dual 2:4 decoder 7404 hex inverter 7400 NAND gate 7432 OR gate 74LS74 dual ‘D’ flip-flop 4511 7-segment trigger 74193 4-bit up/down

counter L293D push-pull 4-channel driver without motor NE555 timer 1N4148 diode 5mm yellow LED 5mm red LED 5mm green LED Infrared transmitter LED Infrared receiver module (TSOP1738) LTS-543 common cathode 7-segment display

Quantity ONE (1) ONE (1) ONE (1) ONE (1) FOUR (4) ONE (1)

ONE (1) ONE (1) TWO (2) TWO (2) ONE (1) ONE (1) ONE (1) TWO (2) TWO (2) ONE (1)

2. Resistors (all ¼ watt, +/-5% carbon unless stated otherwise): Component Name R1, R2 R3, R4 R5, R6, R8 R7, R9

Specification 3.3Kohm 1.8Kohm 100Kohm 1Mohm

26

Quantity TWO (2) TWO (2) THREE (3) TWO (2)


R10 to R19

330Kohm

TEN (10)

Specification 0.22 µ F, ceramic disk 0.01 µ F, ceramic disk 0.47 µ F, 16V electrolytic 22 µ F, 16V electrolytic

Quantity ONE (1) THREE (3) TWO (2) TWO (2)

Specification Push-to-on tactile switch 8-pin bases 14-pin bases 16-pin bases 5V, 1A regulated

Quantity THREE (3) TWO (2) SEVEN (7) FOUR (4) ONE (1)

3.Capacitors Component Name C1 C2 to C4 C5, C7 C6, C8

4. Miscellaneous Component Name S1 to S3 IC Bases IC Bases IC Bases Power supply Flexible wire

D.C. Motor

Motor up to 600mA output convert capability

Chapter 9 27

ONE (1)


Bibliography

28


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

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Car Park Report

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