Ventilation Duct Fault Detector

8/8/2019 Ventilation Duct Fault Detector

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CHAPTER 1

INTRODUCTION

1.1. INTRODUCTIONThe detection of faults inside a HVAC (Heating, Ventilating and Air-

Conditioning) duct is very difficult. The conventional system involves dismantling

of the whole duct to inspect for faults. In recent times, some efforts have been

taken to remove this difficulty with the help of robots. But, these Wireless-

controlled Robots use RF circuits, which have limited working range. Use of a

mobile phone for robotic control can overcome these limitations.

In this project, the robot is controlled by a mobile phone that makes call

to the phone attached to the robot. In the course of call, if any button is pressed,

control corresponding to the button pressed is heard at the end through DTMF.

The received tone is processed by the microcontroller (ATmega16) with

the help of DTMF decoder, which decodes the DTMF tone in to its equivalent

binary digit and this binary numbers are then send to the microcontroller. The

microcontroller is programmed to take a decision for any given input and outputs

it decisions to the motor drivers in order to drive the motors for forward or

backward motion or a turn.

The mobile that makes a call to the mobile attached to the robot acts as a

remote, so this does not require any transmitter or receiver units.

In addition to this DTMF communication, the recent advent in 3G technology

enables us to have video communication between two destinations. Hence enabling

a view of the interior of the ventilation duct.

1.2. OBJECTIVETo design and fabricate ventilation duct fault detector to reduce the

difficulties in ventilation duct maintenance procedures. In conventional system,

dismantling the ventilation duct for maintenance is a cumbersome process and hence

this project aims at simplifying these maintenance procedures.


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CHAPTER - 2

PROBLEM DEFINITION

2.1. EXISTING MODELS

In the existing system, detecting the faults in the ventilation ducts requires

dismantling of the ventilation duct setup.

2.1.1. Manual method

In this method, the ventilation duct has to be taken apart to enable the human

inspection.

2.1.2. Robotic method

In this method, a wired robot is sent into the duct for inspection. In this method

too, the range of operation is constrained by the wires and the physical structure of

the ventilation duct.

2.2. PROPOSED SYSTEM

This project is an enhanced version of the robotic method. In this system, the

ventilation duct fault detector has to be placed inside the duct. For this, only a part ofthe duct structure has to be taken apart and it can be restored to its original shape

later. Then the motion of the detector system can be controlled by the DTMF signals

sent through the hand-held mobile phone. The interior of the ventilation duct can be

viewed with the help of a 3G enabled video call facility in the hand-held phone.

2.3. ADVANTAGES

No need to dismantle the whole ventilation duct. Reduces manpower requirement for maintenance operation. Interior structure of the duct can be seen and also recorded for future

reference.


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CHAPTER - 3

FEASIBILITY STUDY

3.1. ECONOMIC FEASIBILITY

This system can be implemented all over the world because of its simple

architecture, flexibility and low implementation cost.

3.2. OPERATIONAL FEASIBILITY

It is easy to operate. Even unskilled labour can operate this system easily. Because,

the system is programmed in such a manner that the key locations are analogous to the

direction of control with respect to the centre key.

3.3. TECHNICAL FEASIBILITY

In Software side we used simple programming tool called WinAVR which will

compile the written C program into a microcontroller program. In the hardware side we used

only simple components like Microcontroller, DTMF receiver, a motor controller and a

mobile phone.


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CHAPTER 4

DESIGN AND DESCRIPTION

4.1. DESIGN SPECIFICATIONS

Typical Heating, Ventilating, and Air Conditioning (HVAC) ducts used in

industries those supplying 500 litre/hour of conditioned air are in dimensions of

about 180cm*110cm.

Therefore, the proposed model should have thickness and width less than the

ventilation duct.

HEIGHT - less than 110cm WIDTH - less than 180cm

4.2. WHEEL SPECIFICATION

Number of wheels to be used 2

Distributed weight for each wheel 0.7kg

Material to be used Poly Vinyl Chloride

Minimum wheel diameter 65mm

Table 1. WHEEL SPECIFICATION

4.3. MATERIAL USED

Since, the model has to work even under extremely cold temperatures, the

chassis must be made of PVC in order to avoid rust formation.


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4.4.DETAILED DRAWING OF EACH COMPONENT

Figure 4.1. CHASIS

Figure 4.2. BASE


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Figure 4.3. WHEEL

Figure 4.4. CASTER WHEEL


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4.5. ASSEMBLY DRAWING OF THE MODEL

Figure 4.5. ASSEMBLY DRAWING OF THE MODEL

4.6. PHOTOGRAPH OF THE MODEL

Figure 4.6. PHOTOGRAPH OF THE MODEL


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CHAPTER 5

FABRICATION OF MODEL

5.1.PROCESS DESCRIPTION

Figure 5.1. Block diagram of the process

Figure 5.1. shows the block diagram of the circuit of this microcontroller

based robot. The major components of the system are DTMF decoder, microcontroller

(ATmega16) and motor driver (L293D).

An MT8870 series DTMF decoder is used in this circuit, which uses the

digital counting techniques to detect and decode all sixteen DTMF tone pairs into a four

bit code output. The built-in dial tone rejection circuit eliminates the need for pre-

filtering. When the input signal is given at pin2 (IN-) single ended input

configuration is recognized to be effective, the correct four bit decode signal of the

DTMF tone is transferred to Q1 (pin11) through Q4 (pin14) outputs.

The ATmega16 is a low-power, high-performance CMOS 8-bit

microcomputer with 8K bytes of Flash programmable and erasable read only memory

(EPROM). The device is manufactured using Atmels high-density non-volatile

memory technology and is compatible with the industry-standard 80C51 and 80C52

instruction set and pin out.

The on-chip flash allows the program memory to be reprogrammed in-system

or by a conventional non-volatile memory programmer.


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5.2. FEATURES

5.2.1.DTMF communication

DTMF assigns a specific frequency (consisting of two separate tones) to

each keys that it can easily be identified by the electronic circuit. The signal

generated by the DTMF encoder is the direct algebraic submission, in real

time of the amplitudes of two sine or cosine waves of different frequencies i.e.,

pressing 5 will send a tone made by adding 1336 Hz and 770 Hz to the other end

of the mobile phone. The table below shows the corresponding frequencies

generated by the numbered buttons.

Table 2. DTMF& ITS CORRESPONDING FREQUENCY

Thus, DTMF input given from the mobile phone is identified based on the

frequency generated.


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5.2.2. DTMF - Circuit diagram

Figure 5.2. DTMF CIRCUIT DIAGRAM


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5.2.3. 3G TechnologyInternational Mobile Telecommunications-2000 (IMT--2000), better known as

3G or 3rd Generation, is a generation of standards for mobile phones and mobile

telecommunications services fulfilling specifications by the International Tele-

communication Union.

The salient features of 3G technology are

The 3G (UMTS and CDMA2000) research and development projects started in1992. In 1999, ITU approved five radio interfaces for IMT-2000 as a part of the

ITU-R M.1457 Recommendation; WiMAX was added in 2007.

There are evolutionary standards that are backwards-compatible extensions to pre-existing 2G networks as well as revolutionary standards that require all-new

networks and frequency allocations.

The latter group is the UMTS family, which consists of standards developed forIMT-2000, as well as the independently developed standards DECT and WiMAX,

which were included because they fit the IMT-2000 definition.

Application services include

Mobile TVa provider redirects a TV channel directly to the subscriber's phonewhere it can be watched.

Video on demanda provider sends a movie to the subscriber's phone. Video conferencingsubscribers can see as well as talk to each other. Tele-medicinea medical provider monitors or provides advice to the potentially

isolated subscriber.

Location-based servicesa provider sends localized weather or traffic conditionsto the phone, or the phone allows the subscriber to find nearby businesses or friends.

Compared to the older 2G and 2.5G standards, a 3G system must allow

simultaneous use of speech and data services, and provide peak data rates of a minimum of

200 kb/s according to the IMT-2000 specifications.


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5.2.4. AVR development boardThe ATmega16 is a low-power, high-performance CMOS 8-bit

microcomputer with 8K bytes of Flash programmable and erasable read only memory

(EPROM).

The device is manufactured using Atmels high-density nonvolatile memory

technology and is compatible with the industry standard 80C51 and 80C52 instruction

set and pin out.

The on-chip Flash allows the program memory to be reprogrammed in-system

or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit

CPU with Flash on a monolithic chip, the Atmel ATmega16 is a

powerful microcomputer which provides a highly-flexible and cost-effective solution

to many embedded control applications.

Figure 5.3. AVR DEVELOPMENT BOARD


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5.2.4.2. Features

Compatible with MCS-51 Products

8K Bytes of In-System Reprogrammable Flash Memory

Endurance: 1,000 Write/Erase Cycles

Fully Static Operation: 0 Hz to 24 MHz

Three-level Program Memory Lock

256 x 8-bit Internal RAM

32 Programmable I/O Lines

Three 16-bit Timer/Counters

Eight Interrupt Sources

Programmable Serial Channel

Low-power Idle and Power-down Modes

Figure 5.4. PIN CONFIGURATION OF ATMEGA16


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5.2.4. Motor Driver (L293D)The L293D is a monolithic integrated high voltage, high current four channel driver

designed to accept standard DTL or TTL logic levels and drive inductive loads (such as

relays solenoids, DC and stepping motors) and switching power transistors.

To simplify use, two bridges as pair of channels is equipped with an enable input. A

separate supply input is provided form the logic, allowing operation at a low voltage and

internal clamp diodes are included.

Features:

1) 600mA. Output current capability per Channel2) 1.2A peak output current (non-repetitive) per channel3) Over-temperature protection4) Logical 0 input voltage up to 1.5V5) High noise immunity

Figure 5.5. MOTOR DRIVER CIRCUIT DIAGRAM


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5.2.5. DC MotorsIn general, DC motors are similar to DC generators in construction. They may, in

fact, be described as generators run backwards. When current is passed through the

armature of a DC motor, a torque is generated by magnetic reaction, and the armature

revolves. The action of the commutators and the connections of the field coils of motors are

precisely the same as those used for generators. The armature revolution thus constitutes

the motor action. In this system, a 9V, 150rpm geared DC motor is used to run the system.

5.2.6. WinAVR SoftwareWinAVR is a freeware which enable us to incorporate the embedded C programs

into a microcontroller chip. The program pertaining to the motion of the robot can be

written in the C programming language. Then it can be loaded to the microcontroller by

uploading the program through programmers notepad window available in the WinAVR

software.

5.2.7. Working Methodology of the Interfacing BoardIn order to control the robot, a call is made to the phone attached to the robot

from any 3G enabled phone. Now the phone is picked up by the phone on the robot

through auto answer mode.Now after the circuit is ready and all codes are fetched the

robot is ready to be controlled.

Number

Pressed

Output of the

DTMF decoder

Input to the

Microcontroller

Output of the

microcontroller

Action

Performed

2 0x02 (00000010) 0xFD (11111101) 0x09 (00001001) Forward

4 0x04 (00000010) 0xFB (11111011) 0x05 (00000101) Turn Left

6 0x06 (00000110) 0xF9 (11111001) 0x0A (00001010) Turn right

8 0x08 (00001000) 0Xf7 (11110111) 0x06 (00000110) Reverse

5 0x05 (00000101) 0xFA (11111010) 0x00 (00000000) Brake

Table 3. WORKING ACTION PERFORMED


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5.2.8. Cost of the projectSl.No. Component Number of units Cost

(in Rupees)

1. AVR Developer (educational) Kit 1 600

2. Chassis & Wheels 1 350

3. DC motors 2 280

4. DTMF module 1 150

5. 9V battery 4 160

Total cost (excluding mobile phones) Rs.1540/-

Table 4. COST OF THE PROJECT

5.2.9. ApplicationsThe project is not only limited to simple functioning of the robot that

is to move forward, backward, right and left, but it can also be

implemented with some other accessories to watch what is going out in

particular location of the floor in a close circuit monitoring with voicetransmission. This definitely requires a difficult circuitry.

Scientific applicationsDTMF controlled robot have various scientific uses including

hazardous environments, working in deep oceans, and space exploration.

The majority of the probes to the other planets in the solar system have

been remote control vehicles, although some of the most recent ones were

partially autonomous.

Military and Law Enforcement applicationsMilitary usage of remotely controlled military vehicles dates back to

the first half of 20th century. Similarly, we can use this system as a spy


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robot by incorporating some advanced features.

Search and Rescue applicationsThese robots can be used in all kinds of locations and situations thus

making it a versatile application to all search and rescue applications. Recreation and Hobby

Small scale remote control vehicles have long been popular among

people.These remote controlled vehicles span a wide range in terms of price and

sophistication. There are many types of radio controlled vehicles. These include

on-road cars, off-road trucks, boats, airplanes, and even helicopters.


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CHAPTER 6

CONCLUSION& FUTURE ENHANCEMENTS

A novel design of Ventilation Duct Fault Detector has been fabricated and works

successfully. This system can effectively carry out the maintenance procedures in a

ventilation duct. Thus the necessity to dismantle the whole ventilation duct for fault

detection was eradicated. This project is not only restricted for ventilation ducts but also can

be extended by incorporating any of the following features.

Suction Cups:This project can be aided with suction cups which helps the robot wheel to

climb on slanting surfaces more easily without any slippage.

IR Sensors:IR sensors can be used to automatically detect & avoid obstacles if the

robot goes beyond line of sight. This avoids damage to the vehicle if we are

maneuvering it from a distant place.

Password protection:Project can be modified in order to password protect the robot so that it

can be operated only if correct password is entered.

Alarm Phone Dialer:A project called 'Alarm Phone Dialer' can be built which will generate

necessary alarms for something that is desired to be monitored. For example a

high coolant alarm, low temperature alarm, opening of back window, garage

door, and many more. Thus, when the system is activated it will call a number of

programmed numbers to let the user know the alarm has been activated. This

would be great to get alerts of alarm conditions from home when user is at work.


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REFERENCES

1. R.M. Aynsley, W. Melbourn, and B.J. Vickery,Architecturalaerodynamics, Applied Science Publishers, London 1977

2.

The 8051 Microcontroller and EmbeddedSsystems Using Assembly and C byMuhammed Ali Mazidi , Janice Gillispie Mazidi, Rolin D.McKinley

3. Designer's Guide to Ceiling-Based Room Air Diffusion, Rock andZhu, ASHRAE, Inc., Atlanta, GA, USA, 2002

4. Schenker, L (1960), "Pushbutton Calling with a Two-Group Voice-Frequency Code", The Bell system technical journal 39 (1): 235

255, ISSN 0005-8580

5. "What really is a Third Generation (3G) Mobile Technology" - AnInternational Telecommunication Union press release.

6. Minimum wheel-rotation paths for differential drive mobile robots-Matthew T.Mason(International Journal on Robotics)

7. Feasibility study of DTMF Communications for Robots.-Tho Nyugen and Linda G. Bushnell. (UWEE)

8. http://www.alldatasheet.com9. http://www.wikipedia.org10.http://www.google.com
http://en.wikipedia.org/wiki/ASHRAEhttp://docs.google.com/Doc?docid=accnfh3pfb3_205hfvzk5rshttp://docs.google.com/Doc?docid=accnfh3pfb3_205hfvzk5rshttp://en.wikipedia.org/wiki/International_Standard_Serial_Numberhttp://www.worldcat.org/issn/0005-8580http://www.worldcat.org/issn/0005-8580http://www.itu.int/ITU-D/imt-2000/DocumentsIMT2000/What_really_3G.pdfhttp://www.itu.int/ITU-D/imt-2000/DocumentsIMT2000/What_really_3G.pdfhttp://www.worldcat.org/issn/0005-8580http://en.wikipedia.org/wiki/International_Standard_Serial_Numberhttp://docs.google.com/Doc?docid=accnfh3pfb3_205hfvzk5rshttp://docs.google.com/Doc?docid=accnfh3pfb3_205hfvzk5rshttp://en.wikipedia.org/wiki/ASHRAE


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APPENDIX

Source code:

#include

#include"delay.h"

int main(void)

{

PORTB=0x00;

DDRB=0xFF;

PORTA=0xFF;

DDRA=0x00;

while(1)

{

switch(PINA)

{

case 0xF8:

PORTB=0xf1;

break;

case 0xF4:

PORTB=0x05;

break;

case 0xFC:

PORTB=0x04;

break;


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case 0xF2:

PORTB=0x09;

break;

case 0xFA:

PORTB=0x00;

break;

case 0xF6:

PORTB=0x06;

break;

case 0xFE:

PORTB=0x02;

break;

case 0xF1:

PORTB=0x0A;

break;

case 0xF9:

PORTB=0x08;

break;

default:

PORTB=0x00;

break;

}}}


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Flow-chart (program):

Figure 6. FLOW CHART (PROGRAM)


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SCREENSHOTS

Opening the WinAVR software WinAVR programming

WinAVR ATmega selection

Figure 7. SCREENSHOTS OF WINAVR

Ventilation Duct Fault Detector

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