ALIVE HUMAN BEING DETECTOR ROBOT

2012-05-07T02:04:00.001-07:00

1.INTRODUCTION

Disasters can disrupt economic and social balance of the society. Because of high rise buildings and other manmade structures urban and industrial areas are considered to be more susceptible to disasters. These disasters can be categorized into natural and human induced disasters. Natural disasters include floods, storms, cyclones, bush fire, earthquakes etc whereas human induced disasters include transportation accidents, industrial accidents, major fires etc.

During these emergency situations, and especially in urban disaster, in order to prevent loss of life and property, various essential services (like policeman, fire fighters and medical assistance etc) are deployed. They need to cooperate to save lives, protect structural infrastructure, and evacuate victims to safety. In such situations, human rescuers must make quick decisions under stress, and try to get victims to safety often at their own risk. They must gather determine the location and status of victims and the stability of the structures as quickly as possible so that medics and firefighters can enter the disaster area and save victims. All of these tasks are performed mostly by human and trained dogs, often in very dangerous and risky conditions. But the rescue operations with the help of trained humans or dogs are greatly time consuming and one can never guarantee the success of such operation. Moreover there are chances for the loss of lives of rescuers during such risky and dangerous operations. Due to the above reasons mobile robots have been proposed to help the rescuers and to perform tasks that neither humans, dogs nor existing tools can do. Such simulated robots should have the capability to determine its current location in real-time and to wirelessly communicate with the rescue team.

Hence in this project, we focus on a system named as ‘Alive Human Being Detector’ which will work in disaster environments of manmade structures like collapsed buildings, war fields etc. It can assist firemen, police, and disaster agencies with reconnaissance, site evaluation, human detection etc.

The aim of this work is to provide a low cost, semi-autonomous, heterogeneous, and user friendly sensor suite for human detection in the disaster environment. Conditions in a disaster area are extreme with many unknown parameters. Victims may be covered in debris, trapped in voids, or entombed, making it difficult to find them and determine their state of health. This is why it will be important to choose a set of different sensors which are complementary and able to operate in these conditions.

A rescue robot is a robot that has been designed for the purpose of aiding rescue workers. Common situations that employ rescue robots are mining accidents, urban disasters, hostage situations, and explosions. Rescue robots were used in the search for victims and survivors after the September 11 attacks in New York.The benefits of rescue robots to these operations include reduced personnel requirements, reduced fatigue, and access to otherwise unreachable areas.

Our project aims to develop an economic robot, which works in dtmf technology. It can be used in areas were rescue needed, the robot senses the temperature and alarm will be produced when it detects alive body and rescue operation can be done in following areas.

2. SYSTEM FEATURES

2.1 BLOCK DIAGRAM

Fig 2.1.1 Block diagram

2.2 BLOCK DIAGRAM EXPLANATION

The first block is the mobile phone, from which the DTMF technology is being used. The output of the mobile is given to the DTMF decoder IC MT8870.The PIC microcontroller used here is 16F873A. Output of the IC is given to the PIC from where which it goes to the motor driver.L293A is used here. According to the instructions given through the mobile ,robot can be moved in respective directions. For temperature sensing LM 35 is used.3 motors are there. A feedback switch is also provided.

2.2.1 DTMF KEYPAD

The DTMF keypad is laid out in a 4×4 matrix, with each row representing a low frequency, and each column representing a high frequency. Pressing a single key (such as '1' ) will send a sinusoidal tone for each of the two frequencies (697 and 1209 Hertz (Hz)). The original keypads had levers inside, so each button activated two contacts. The multiple tones are the reason for calling the system multi frequency. These tones are then decoded by the switching center to determine which key was pressed.

DTMF keypad frequencies (with sound clips)
	1209 Hz	1336 Hz	1477 Hz	1633 Hz
697 Hz	1	2	3	A
770 Hz	4	5	6	B
852 Hz	7	8	9	C
941 Hz	*	0	#	D

Table 2.2.1.1 DTMF keypad

2.2.2 DTMF DECODER

This circuit detects the dial tone from a telephone line and decodes the keypad pressed on the remote telephone. The dial tone we heard when we pick up the phone set is call Dual Tone Multi-Frequency, DTMF in short. The name was given because the tone that we heard over the phone is actually make up of two distinct frequency tone, hence the name dual tone. The DTMF tone is a form of one way communication between the dialer and the telephone exchange.

A complete communication consist of the tone generator and the tone decoder. In this article, we are use the IC MT8870DE, the main component to decode the input dial tone to 5 digital output. These digital bits can be interface to a computer or microcontroller for further application (eg. remote control, phone line transfer operation, etc...).

Detection of dial tones is reflected on the bit TOE, while the output Q4, Q3, Q2, Q1 indicate the dial tone that is being detected on the telephony system. A complete table of the decoded digital output for individual dial tone is available in the coming section.

2.2.3 PIC MICROCONTROLLER

The PIC microcontroller family is manufactured by Microchip Technology Inc. Currently they are one of the most popular microcontrollers, used in many commercial and industrial applications. Over 120 million devices are sold each year. The programmability and the versatile applications for which a PIC microcontroller can be used have made it a first choice in small scale applications and project work.

The PIC microcontroller architecture is based on a modified Harvard RISC (Reduced Instruction set Computer) instruction set with dual-bus architecture, providing fast and flexible design with an easy migration path from only 6 pins to 80 pins, and from 384 bytes to 128 kilobytes of program memory.

PIC microcontrollers are available with different specifications depending on:

• Memory Type

– Flash

– OTP (One-time-programmable)

– ROM (Read-only-memory)

– ROM less

• Input–Output (I/O) Pin Count

– 4–18 pins

– 20–28 pins

– 32–44 pins

– 45 and above pins

• Memory Size

– 0.5–1 K

– 2–4 K

– 8–16 K

– 24–32 K

– 48–64 K

All PIC microcontrollers offer the following features

• RISC instruction set with only handful of instructions to learn

• Digital I/O

• On chip timer

• Power-on-reset

Power-saving sleep mode

• High source and sink current

• Direct indirect and relative addressing modes

• External clock interface

• RAM data memory

• EPROM or flash program memory

Some devices offer the following additional features

• Analog input channel

• Analog comparators

• Additional timer circuit

• EEPROM data memory

• External and internal interrupts

• Internal oscillator

• PWM output

• USART serial interface.

Fig:2.2.3.1 PIC 16F873

2.2.4 MOTOR DRIVER

To rotate the motor as per human instructions we have to interface the motor with a microcontroller. But the output current of microcontroller is not sufficient to drive a dc motor. So we use motor drivers. Usually H bridge is preferred way of interfacing a DC motor.

L293D is a dual H bridge motor driver. The name "H Bridge" is derived from the actual shape of the switching circuit which controls the motion of the motor. It is also known as "Full Bridge". Basically there are four switching elements in the H Bridge as shown in the figure below named as "High side left", "High side right", "Low side right", "Low side left". When these switches are turned on in pairs motor changes its direction accordingly. Like, if we switch on High side left and Low side right then motor rotate in forward direction, as current flows from power supply through the motor coil goes to ground via switch low side right. Similarly, when we switch on low side left and high side right, the current flows in opposite direction and motor rotates in backward direction. This is the basic working of HBridge.

Fig 2.2.4.1 L293D MOTOR DRIVER

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2.2.5 TEMPERATURE SENSOR-LM35

A sensor can be regarded as a transducer which can convert one form of energy in to another form. It can be used to sense the vital signs parameter for checking whether a person is alive or not. Body temperature is one of the most important vital sign parameter which can give information about the condition of a person. So here we use sensor to sense the body temperature. Temperature sensors consist of temperature sensitive resistors whose resistance vary with temperature. Hence such devices can produce output voltages that are proportional to the temperature. This sensor output is processed by the microcontroller .LM35 is a commonly available temperature sensor having positive temperature coefficient of resistance. i.e., the output voltage of the sensor increases with temperature.

Fig 2.2.5.1 LM35

2.2.6 WIRELESS CAMERA

Wireless security cameras are Closed Circuit Television (CCTV) cameras that transmit a video and audio signal to a wireless receiver through a radio band. Many wireless security cameras require at least one cable or wire for power; "wireless" refers to the transmission of video/audio. However, some wireless security cameras are battery-powered, making the cameras truly wireless from top to bottom. Wireless cameras are proving very popular among modern security consumers due to their low installation costs (there is no need to run expensive video extension cables) and flexible mounting options; wireless cameras can be mounted/installed in locations previously unavailable to standard wired cameras.

Fig 2.2.6.1 Wireless camera

Wireless security cameras function best when there is a clear line of sight between the camera(s) and the receiver. Outdoors, and with clear line of sight, digital wireless cameras typically have a range between 250 to 450 feet. Indoors, the range can be limited to 100 to 150 feet. The signal range varies depending on the type of building materials and/or objects the wireless signal must pass through.

2.2.7 ALARM

The alarm will be activated if and only if the human body is alive.

3. HARDWARE IMPLEMENTATION

3.1 CIRCUIT DIAGRAM

fig3.1.1 circuit diagram

3.2 CIRCUIT EXPLANATION

3.2.1 DTMF SECTION

The very first section is the DTMF section.DTMF can be expanded as Dual Tone Multi Frequency.Every key in the mobile phone keypad has a particular frequency associated with it,which is the combination of an upper frequency(coloum) and a lower frequency(row).When a particular key is pressed a combinatinl frequency arrives at the input of the decoder.

WORKING

The combinational frequency that arrives at the input of the DTMF decoder IC will be decoded into four output bits.The strobe pin of the decoder IC will be high if and only if there is a signal at its input.Tho output bits are available as Q3,Q2,Q1,Q0.The output of the decoder is given to port C of microcontroller.PIC16F873A is the microcontroller used here.It is a 28 pin package IC,which has 3 ports and all the 3 ports are being used here.Port A is the input port.To this port the temperature sensor is connected.Port B is the output port.Connections to the motor drivers are done from this port.These motor drivers drive three gear motors which work on a power supply of 6volts.Two of these act as whels of the robot and the other one is for controlling the movement of arm that holds the temperature sensor.

As a whole the robot’s movement is controlled with the key pressed on mobile phone.The path covered by the robot is viewed in a PC using a wireless camera.Temperature sensor senses the temperature of the victim and it will be compared with the already set reference temperature of the pic.If the measured temperature is greater than the reference temperature alarm will be activated, indicating that detected body is alive.

4. SOFTWARE DEVELOPMENT

4.1 FLOW CHART

SET THE ADCON REGISTERS

STOP

Fig 4.2.1 flow chart

4.3 ALGORITHM

· STEP 1: START

· STEP2: INITIALISE VARIABLES

· STEP3: CHECK IF DTMF DATA IS AVAILABLE

o IF NO RECHECK,

o IF YES GOTO STEP4

· STEP4 :IF DTMF DATA=2, MOVE FORWARD

o IF DTMF DATA=8, MOVE BACKWARD

o IF DTMF DATA=4, TURN LEFT

o IF DTMF DATA=6,TURN RIGHT

o IF DTMF DATA=#, STOP

o IF DTMF DATA =5,ARM DOWN—SENSE TEMP

· STEP5: IF TEMP>SET TEMP----ALARM ACTIVATED

o ELSE ARM UP…GOTO STEP 3

4.3 SOFTWARE TOOLS

4.3.1 MICROCHIP TECHNOLOGY

Microchip Technology (NASDAQ: MCHP) is an American manufacturer of microcontroller, memory and analog semiconductors. Its products include microcontrollers (PICmicro, dsPIC / PIC24, PIC32), Serial EEPROM devices, Serial SRAM devices, KEELOQ devices, radio frequency (RF) devices, thermal, power and battery management analog devices, as well as linear, interface and mixed signal devices. Some of the interface devices include USB, ZigBee/MiWi, Controller Area Network, and Ethernet.

Corporate headquarters is located at Chandler, Arizona with wafer fabs in Tempe, Arizona and Gresham, Oregon.Among its chief competitors are Analog Devices, Atmel, Freescale, Infineon, Maxim Integrated Products, NXP Semiconductors, Renesas Electronics, STMicroelectronics, and Texas Instruments

4.3.2 EMBEDDED C

Embedded C is a set of language extensions for the C Programming language by the C Standards committee to address commonality issues that exist between C extensions for different embedded systems. Historically, embedded C programming requires nonstandard extensions to the C language in order to support exotic features such as fixed-point arithmetic, multiple distinct memory banks, and basic I/O operations.

In 2008, the C Standards Committee extended the C language to address these issues by providing a common standard for all implementations to adhere to. It includes a number of features not available in normal C, such as, fixed-point arithmetic, named address spaces, and basic I/O hardware addressing

5. PCB DESIGN

A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board (PWB) or etched wiring board. A PCB populated with electronic components is a printed circuit assembly (PCA), also known as a printed circuit board assembly (PCBA).

Printed circuit boards are used in virtually all but the simplest commercially-produced electronic devices. PCBs are inexpensive, and can be highly reliable. They require much more layout effort and higher initial cost than either wire wrap construction, but are much cheaper and faster for high-volume production; the production and soldering of PCBs can be done by totally automated equipment. Much of the electronics industry's PCB design, assembly, and quality control needs are set by standards that are published by the IPC organization.

Conducting layers are typically made of thin copper foil. Insulating layers dielectric is typically laminated together with epoxy prepreg. The board is typically coated with a solder mask that is green in color. Other colors that are normally available are blue, black, white and red. There are quite a few different dielectrics that can be chosen to provide different insulating values depending on the requirements of the circuit. FR-4 is by far the most common material used today. The board with copper on it is called "copper-clad laminate".

PATTERNING (ETCHING)

The vast majority of printed circuit boards are made by bonding a layer of copper over the entire substrate, sometimes on both sides, (creating a "blank PCB") then removing unwanted copper after applying a temporary mask (e.g. by etching), leaving only the desired copper traces. A few PCBs are made by adding traces to the bare substrate (or a substrate with a very thin layer of copper) usually by a complex process of multiple electroplating steps. The PCB manufacturing method primarily depends on whether it is for production volume or sample/prototype quantities.

The dimensions of the copper conductors of the printed circuit board are related to the amount of current the conductor must carry. Each trace consists of a flat, narrow part of the copper foil that remains after etching. Signal traces are usually narrower than power or ground traces because their current carrying requirements are usually much less. In a multi-layer board one entire layer may be mostly solid copper to act as a ground plane for shielding and power return. For printed circuit boards that contain microwave circuits, transmission lines can be laid out in the form of strip line and micro strip with carefully-controlled dimensions to assure consistent impedance. In radio-frequency circuits the inductance and capacitance of the printed circuit board conductors can be used as a deliberate part of the circuit design, obviating the need for additional discrete components.

ETCHING

Chemical etching is done with ferric chloride, ammonium persulfate, or sometimes hydrochloric acid. For PTH (plated-through holes), additional steps of electrolysis deposition are done after the holes are drilled, then copper is electroplated to build up the thickness, the boards are screened, and plated with tin/lead. The tin/lead becomes the resist leaving the bare copper to be etched away.

LAMINATION

Some PCBs have trace layers inside the PCB and are called multi-layer PCBs. These are formed by bonding together separately etched thin boards.

DRILLING

Holes through a PCB are typically drilled with tiny drill bits made of solid tungsten carbide. The drilling is performed by automated drilling machines with placement controlled by a drill tape or drill file. These computer-generated files are also called numerically controlled drill (NCD) files or "Excellon files". The drill file describes the location and size of each drilled hole. These holes are often filled with annular rings (hollow rivets) to create vias. Vias allow the electrical and thermal connection of conductors on opposite sides of the PCB.

5.1 PCB DESIGN AND FABRICATION

Designing of a PCB is a major slip in the production of PCBs. It forms a distinct factor n electronic performance and reliability. The productivity of a PCB with assembly and serviceability also depends on design.

STEPS INVOLVED

1. Prepare the required circuit diagram

2. List out the components, their sizes etc.

3. Draft it onto a graph sheet

4. Place all pads and finish thin tracks

5. Put it on the mylor sheet and then on the graph sheet

6. Place parts including screw holes with the help of knife.

7. Fix all the tracks.

8. Keep one component as the key.

CONVERSION OF CIRCUIT DIAGRAM

1. Cutting lines, mounting lines are done

2. List all the components their length diameter thickness code names etc.

3. Keep one component as key component

4. Keep key component first and their supporting tools

5. All tracks are straight lines

6. In between ICs no signal lines should be passed

7. Mark the pin number of IC on the lay out for avoiding dislocations

8. The length of the conductor should be as low as possible

9. Place all the components, resistors, diodes etc. parallel to each other

LAY OUT APPROACHES

First the board outlines and the connectors are marked on a sheet of paper followed by sketching of the component outlines with connecting point and conductor patterns. Prepare the layout as viewed from the component side first, so as to avoid any confusion. The layout is developed in the direction of signal flow as far as possible. Among the components the larger ones are filled first and the space between is filled with smaller ones. Components, rewiring input, output connections came near the connectors. All the components are placed in such a manner that de-soldering of the component is not is not necessary, if they have to be re placed. While designing the conductors, the minimum spacing requirement for the final network should be known. Transforming the lay out to copper. The lay out made on the graph sheet should be redrawn on the copper clad using paint or nail polish.

ETCHING

The final copper pattern is formed by selective removal of the unwanted copper which is not protected by an electric rebist. FeCl3 solution is popularly used etching solution. FeCl3 powder is made into a solution using water and kept in a plastic tray. Immerse the marked copper clad in this solution for two or three hours. Due to the reaction solution will became weak and it is not recommended for further etching process. Take out the etched sheet from the tray and dry out for in sunlight for an hour.

ETCHANTS

Many factors have to be considered to choose the most suitable etchant system for a PCB process. Some commonly used etchants are FeCl3, Cupric chloride, Chromic acid etc. After etching FeCl3 is washed from the board and cleaned dry. Paint is removed using suitable from the component insertion. Holes are drilled into appropriate position and the components are soldered into PCB carefully.

Take a copper clad of the required dimensions. Transfer the circuit layout to the copper clad using cotton paper. The layout area should be marked with nail polish. Put the copper clad into FeCl3 solution and warm it. Stage by stage transformation of the copper clad occurs. Warm the solution intermittently according to the requirement. After about 4 hours etching will be completed. Wash the board using soap solution to remove the remaining of FeCl3 solution. Scrap off the nail polish and drill holes wherever required using appropriate drill bits. PCB is fabricated.

5.2 PCB LAYOUT

Fig:5.3.1 PCB LAYOUT

5.3 COMPONENT LAYOUT

Fig5.4.2 COMPONENT LAYOUT

6. ADVANTAGES AND DISADVANTAGES

6.1 ADVANTAGES

• Economic

• Fast

• Reliable

• Semi autonomous

• User friendly

• Adaptable

6.2 DISADVANTAGES

• Night time work difficult

• Range limitations

7. APPLICATION AND FUTURE ENHANCEMENT

Alive Human Being Detector finds applications mainly in disaster management and crisis management. Some of its major applications are listed below.

• In military applications to detect the presence of human being.

• In Rescue operations where human reach is impossible.

• In Disaster management

• In Crisis management

• This equipment can be used at mines, earthquake prone places

• In Medical field

IN FUTURE:

• Include flying options in robot

• Make the robotic arm capable of up/down movement

• Modify its shape to pass through complex environments or to climb some obstacles.

• Include sensors to sense more vital sign parameters such as heart beat, ECG, EEG, eyeball movement etc.

• Make the robot capable of carrying the victim to secure places.

• Include metal detectors and bomb sensors to detect the presence of bomb in Warfield and in rescue operations.

• Include proper lighting options for night time usage.

8. CONCLUSION

Alive Human Being Detector is an autonomous robot for detecting alive humans in destructed environments. This Alive human body detection system uses temperature sensor, mobile phone, wireless camera and PIC microcontroller to transmit and analyze conditions of human body. The task of identifying human being in rescue operations is difficult for the human agent but it is simple for the robotic agent. In order to detect a human body, an autonomous robot must be equipped with a specific set of sensors that provide information about the presence of a person in the environment around. This system uses a temperature sensor in order to detect the existence of living humans and a low cost camera in order to acquire a video of the scene as needed. The wireless camera shows the path moved by the robot that is displayed on a laptop at the control section. This approach requires a relatively small number of data to be acquired and processed during the rescue operation. This way, the real-time cost of processing and data transmission is considerably reduced. This system has the potential to achieve high performance in detecting alive humans in devastated environments relatively quickly and cost-effectively.

The future work would be to improve detection using more reliable sensors and to modify its shape to pass through complex environments or to climb some obstacles. To have a better quality of human detection, it would be a good solution to add a long distance sensor. Finally, the most challenging part would be to maximize the autonomy of the robot to limit user attention to it.

TEST RESULT

Alive Human Being Detector based on DTMF technology was developed and alive human victims were detected with the simple temperature sensor IC.

9.REFERENCES

www.laxmiinfotech.com

www.sunrome.com

William stallings,”wireless communication and networking”,PRENTICE-HALL of India Pvt.Ltd

Dreamtech software team “Programming for Embedded System”

electromania

ALIVE HUMAN BEING DETECTOR ROBOT

electronics extra reading and reference