DETECTOBOT FULL REPORT
- 1. 1 DETECTOBOT War Tank Wireless Navigation Control
- 2. 2 DETECTOBOT The report submitted to JNTUH in partial fulfilment of the Requirements for the award of the degree of BACHELOR OF TECHNOLOGY In MECHANICAL ENGINEERING Submitted by Md Hasan Ali (10N91A0331) Md Abdul Akheel (10N91A0330) Syed Mobeenoddin (10N91A0357) Syed Raufuddin (10N91A0335) Md Umair Ahmed (10N91A0338) Under the esteemed guidance of Smt.sri Deepthi. I Assistant Professor Department of Mechanical Engineering JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD VIVEKANANDA INSTITUTE OF TECHNOLOGY & SCIENCE (N9) KARIMNAGAR (505001) ANDHRAPRADESH Opp: Housing Board Colony, Bye-Pass Road, Karimnagar-505001 (2010-2014)
- 3. 3 JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY VIVEKANANDA INSTITUTE OF TECHNOLOGY AND SCIENCE KARIMANAGAR (505001) DEPARTMENT OF MECHANICAL ENGINEERING College Code N9 CERTIFICATE This is to certify that the project entitled “DETECTOBOT”, is bonafide work of Md Hasan Ali(10N91A0331) & Syed Mobeenuddin (10N91A0357), Md Abdul Akheel (10N91A0330), Syed Raufuddin (10N91A0335), Md Umair Ahmed (10N91A0338) submitted to the faculty of mechanical engineering in partial fulfilment of the requirements for the award of the Degree of Bachelor of Technology in Department of Mechanical Engineering, from Jawaharlal Nehru Technological University Hyderabad. The work embodied in this technical has not been submitted to any other institution for the award of any degree. Signature of guide SMT.Sri Deepthi.I Asst.professor Vivekananda Institute of Technology & Science Karimnagar-505001 signature head of the Department SMT.Sri Deepthi.I, Asst Professor, Head of Department of ME, Vivekananda Institute of Technology
- 4. 4 ABSTRACT Need Many advances in technology have been providing many solutions in protection, either it be the protection of our homes or it be in the land of border security, in which we are losing lives of many security forces men and other high profile personnel. One of the ways of reducing this loss of lives is to keep regular eye at places of having no risk of lives at all. If something terrible happens at your job, you might file a report about it and your boss will follow up on it. If something terrible happens at a bomb tech’s job, they might get exploded. A tragedy if it’s a human being. But if it’s a robot? A small lump sum out of the defence budget. Robots have been asked to perform jobs in some pretty intense places, from war zones in the Middle East to the surface of Mars to the unexplored corners of Egypt's Great Pyramid. Today, almost all the military organizations take the help of military robots to carry out many risky jobs that cannot be handled manually by soldier. We have also seen a great development in military robots when compare to military robots in earlier time. At present, different military robots are utilized by many military organizations. This robot utilizes two DC motors along with tank belts which are flexible enough to climb small obstacles, controlled by a wireless remote control, and an onboard camera rotating 360 degrees giving a complete picture of surrounding and providing an extra feature of visual intelligence. A microcontroller controls the DC motors in order to move the vehicle on the ground. The movement of the DC motors is in clock and anti-clockwise direction. The navigation system is the important factor in the robot as it utilizes the movement of belts which can almost run on any surface letting it be one of the finest navigating robots.
- 5. 5 Objective Objective of this project is to save human lives by continuously monitoring the surroundings and detect, being live feed has a great advantage of where actually the destity is going on. The use of robots in warfare, although traditionally a topic for science fiction, is being researched as a possible future means of fighting wars. Already several military robots have been developed by various armies. Military robots come in different shapes and sizes as per the task they are designated for. In the development of military robots, we can consider US Mechatronics which has created or developed a working automated sentry gun and is presently developing it further for commercial as well as military use. As far as military robots development is concerned, we cannot forget MIDARS which is a four-wheeled military robot. This robot is outfitted with many cameras, radar, and a firearm that performs arbitrary patrols around a military base automatically. Military robotics isn’t about creating an army of humanoids but utilization of robotics technology for fighting terror and defending the nation. Thus, military robots need not be humanoids or they not necessarily need to carry weapons, they are just those robots that can help the armed forces. The opportunities offered by these technologies are boundless. Pretty much by definition, the military is a dangerous place for humans. This makes it a logical application for robotics. Robotics has been a staple of advanced manufacturing for over half a century. As robots and their peripheral equipment become more sophisticated, reliable and miniaturized, these systems are increasingly being utilized for military and law enforcement purposes. Mobile robotics play an increasingly important role in military matters, from patrol to dealing with potential explosives. Implementation The mobile robotic platform is mounted on a rectangular box with electronic equipment. The platform moves on wheels or tracks, or both, and is usually battery-powered. Communication equipment and sensors can detect images.
- 6. 6 Mobile robotic platforms used in national security applications must move within unstructured environments. “The ability to operate over challenging terrain and the ability to autonomously navigate in unstructured environments are areas of focus for this project. Result Implementation in sand and harsh environments has been done and positive results have been obtained clearing almost any obstacle within its range of height this robot has been tested.
- 7. 7 CONTENTS Chapter 1: Introduction 1.1 Area of Research 1.2 Motivation 1.3 Objective Chapter 2: Introduction to Embedded Systems 2.1 What is an embedded system? 2.2 Features of embedded systems 2.3. Applications of Embedded Systems 2.3.1 Consumer applications 2.3.2 Office automation 2.3.3 Industrial automation 2.3.4 Medical electronics Chapter 3: Microcontroller 3.1 AT89S52 3.2 Features 3.3 Pin Configuration 3.4 History Of 8051 3.4.1 AT89S52 3.4.2 Introduction to AT89S52 3.4.3 Pin Diagram Chapter 4: HT 12E ENCODER 4.1 Features 4.2 Applications 4.3 General Description Chapter 5: 433 MHZ RF TRANSMITTER STT-433 5.1 Overview 5.2 Features CHAPTER 6:433 MHZ RF RECEIVER STR-433
- 8. 8 6.1 Overview 6.2 Features 6.3 Applications Chapter 7: Relays 7.1 Overview of Relays Chapter 8: ULN 2003 8.1 Darlington Pair Chapter 9: Gear Motor 9.1 Operation Principle 9.1.1 Gear 9.2 Speed Reduction 9.3 Torque Multiplication 9.4 Application Chapter 10: Regulated Power Supply 10.1 Transformer 10.2 rectifiers 10.2.1 Types of Rectifiers 10.2.1.1 Comparison of Rectifiers 10.3 Operation 10.4 Filter 10.5 Capacitor 10.6 Regulator 10.7 Features Chapter 11: Hardware Configuration 11.1 wireless camera 11.2 The chassis
- 9. 9 11.3 Anti corrosion paint Chapter 12: Other Aspects 12.1 Advantages 12.2 Application 12.3 Future Scope and Aspects Conclusions References List of Figures Chapter 2 Fig 2.1 Microwave Oven Fig 2.2 Kitchen Equipment Fig 2.3 Coffee Maker Fig 2.4 Fax Machine Fig 2.5 Printing Machine Fig 2.6 Robot Fig 2.7 Industrial Application Fig 2.8 Hearts Beat Monitoring Fig 2.9 Pulse Monitoring Fig 2.10 Temperature Monitoring Fig 2.11 Attendant Calling Fig 2.12 Computer Software Fig 2.13 Tele Communications Fig 2.14 Web Camera Chapter 3 Fig 3.1 Pin Configuration Fig 3.2 At89s52 Fig 3.3 Block Diagram Fig 3.4 Pin Diagram Fig 3.5 Functional Block Diagram
- 10. 10 Fig 3.6 Oscillator And Timing Circuit Chapter 4 Fig 4.1 Ht12e Encoder Fig 4.2 Pin Description Fig 4.3 Block Diagram Chapter 5 Fig 5.1 433 M Hz RF Transmitters STT 433 Chapter 6 Fig 6.1 433 M Hz RF Receivers STR 433 Chapter 7 Fig 7.1 Relay Fig 7.2 Switch Contacts Fig 7.3 SPDT Relay Fig 7.4 SPDT Relay Rest Fig 7.5 SPDT Relay Not Energised Fig 7.6 SPDT Relay Energised Fig 7.7 SPDT Relay Complete Diagram Chapter 8 Fig 8.1 ULN 2003 Fig 8.2 Pin Connection And Block Diagram Fig 8.3 Darlington Pair Chapter 9 Fig 9.1 Gear Connection Fig 9.2 Dc Gear Motor Fig 9.3 Motor Adjustment Fig 9.4 Gear Alignment Fig 9.5 Gear Movement Chapter 10 Fig 10.1 Components of Power Supply Fig 10.2 Transformer Fig 10.3 Rectifier
- 11. 11 Fig 10.4 Operation Fig 10.5 Alternating Current In Relay Fig 10.6 3 Terminal Voltage Regulator Chapter 11 Fig 11.1 Wireless Camera Fig 11.2 Chassis LIST OF TABLES Chapter 3 Table No 3.1 Port Pin And Alternating Function Table No 3.2 Port Pin And Alternating Function 2 Chapter 4 Table No 4.1 Pin Descriptions Table No 4.2 Transmission Pin Descriptions Chapter 5 Table No 5.1 Specification Table No 5.2 Pin Descriptions Chapter 6 Table No 6.1 Specification of Receiver Table No 6.2 Pin Outs and Description Chapter 10 Table No 10.1 Rectifier Parameters and Types
- 12. 12 CHAPTER 1 INTRODUCTION 1.1 Area of Research Mechatronics is a design process that includes a combination of mechanical engineering, electrical engineering, telecommunications engineering, control engineering and computer engineering. Mechatronics is a multidisciplinary field of engineering, that is to say, it rejects splitting engineering into separate disciplines. Originally, Mechatronics just included the combination of mechanics and electronics, hence the word is a combination of mechanics and electronics; however, as technical systems have become more and more complex the word has been broadened to include more technical areas. Mechanical modelling calls for modelling and simulating physical complex phenomenon in the scope of a multi-scale and multi-physical approach. This implies to implement and to manage modelling and optimization methods and tools, which are integrated in a systemic approach. The specialty is aimed at students in mechanics who want to open their mind to systems engineering, and able to integrate different physics or technologies, as well as students in Mechatronics who want to increase their knowledge in optimization and multidisciplinary simulation techniques. The specialty educates students in robust and/or optimized conception methods for structures or many technological systems, and to the main modelling and simulation tools used in R&D. Special courses are also proposed for original applications (multi-materials composites, innovating transducers and actuators, integrated systems, …) to prepare the students to the coming breakthrough in the domains covering the materials and the systems. For some Mechatronics systems, the main issue is no longer how to implement a control system, but how to implement actuators. Within the Mechatronics field, mainly two technologies are used to produce movement/motion.
- 13. 13 1.2 Motivation Motivation towards this project was when the killing of one of the military personnel due to unusual circumstances while patrolling, and hence this project has been made so that to send this robot for patrolling rather than sending a human which would rather save his life. Until recently, robots have not been capable of understanding and coping with unstructured environments (like the ones humans work in) because their systems have relied on knowing in advance the specifics of every possible situation they might encounter. Each response to a contingency has had to be programmed in advance, and systems have had to rebuild their world model from sensor data each time they had to perform a new task. This research is part of a large project which its main objective is to build an autonomous and social robot. The robot must learn to select the right behaviours in order to achieve its goals. The mechanisms involved in the decision making process are inspired on those used by humans and animals. Since it is a social robot, one of the required features would be the life-like appearance. The social aspect of the robot will be reflected in the fact that the human interaction is not going to be considered as a complement of the rest of functionalities of the robot, but as one of its basic features. For this kind of robots autonomy and emotions make them behave as if they were ''alive''. This feature would help people to think of them not as simple machines, but as real companions. For certain applications, a robot with its own personality is more attractive than another that simply executes the actions that it is programmed to do 1.3 Objective Robotics is done with many different objectives, often at the same time. These include creating useful controllers for real-world robot tasks, exploring the intricacies of evolutionary theory. This is very time consuming, which is one of the reasons why controller evolution is usually done in software. Also, initial random controllers may exhibit potentially harmful behaviour, such as repeatedly crashing into a wall, which may damage the robot, and certainly the objective is defined to be the main intention in this case of robot automation.
- 14. 14 CHAPTER 2 INTRODUCTION TO EMBEDDED SYSTEMS 2.1 What is an embedded system? An embedded system is a computing device, which is a combination of both hardware and software used to perform a specific task at specific intervals of time Eg: Microwave oven, washing machines, vcd players etc 2.2 Features of embedded systems: 1. This system can do a specific task and cannot be programmed to do different operated things 2. The software that is used in the embedded system is fixed (i.e., like in computers multi software’s are used at a time) 3. The power consumption for the embedded system is very low 4 Embedded systems have very limited resources. Nearly 99% of the processors are manufactured using embedded systems 2.3. Applications Of Embedded Systems 2.3.1. Consumer applications:
- 15. 15 At home we use a number of embedded systems which include microwave oven, remote control, vcd players, dvd players, camera etc…. Microwave oven: FIG 2.1 Automatic kitchen equipments: FIG 2.2 Automatic coffee makes equipment:
- 16. 16 FIG 2.3 2.3.2 Office automation: We use systems like fax machine, modem, printer etc… Fax machine: FIG 2.4 Printing machine FIG 2.5
- 17. 17 2.3.3 Industrial automation: Today a lot of industries are using embedded systems for process control. In industries we design the embedded systems to perform a specific operation like monitoring temperature, pressure, humidity ,voltage, current etc.., and basing on these monitored levels we do control other devices, we can send information to a centralized monitoring station. Robot: FIG 2.6 In critical industries where human presence is avoided there we can use Robots which are programmed to do a specific operation. Industrial equipments:
- 18. 18 FIG 2.7 2.3.4 Medical electronics: Heart beat monitoring cum controlling equipment: FIG 2.8
- 19. 19 Pulse monitoring system: FIG 2.9 Almost every medical equipment in hospitals are embedded systems eg.. , like EEG, ECG, scanners, endoscopes, X-Ray etc..,, Temperature monitoring equipment:
- 20. 20 FIG 2.10 Nurse and attendant calling systemusing embedded systems. FIG 2.11 Computer networking: Embedded systems are used as bridges routers etc..
- 21. 21 FIG 2.12 Tele communications: Cell phones, web cameras etc.. FIG 2.13
- 23. 23 CHAPTER 3 MICROCONTROLLER 3.1 AT89S52: The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8k bytes of in-system programmable Flash memory. The device is manufactured using Atmel’s high- density nonvolatile memory technology and is compatible with the industry-standard 80C51 instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory pro- grammer. By combining a versatile 8-bit CPU with in-system programmable Flash on a monolithic chip, the Atmel AT89S52 is a powerful microcontroller which provides a highly-flexible and cost-effective solution to many embedded control applications. The AT89S52 provides the following standard features: 8K bytes of Flash, 256 bytes of RAM, 32 I/O lines, Watchdog timer, two data pointers, three 16-bit timer/counters, a six-vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator, and clock circuitry. In addition, the AT89S52 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port, and interrupt system to continue functioning. The Power-down mode saves the RAM con- tents but freezes the oscillator, disabling all other chip functions until the next interrupt or hardware reset. 3.2 FEATURES: • COMPATIBLE WITH MCS-51® PRODUCTS • 8K BYTES OF IN-SYSTEM PROGRAMMABLE (ISP) FLASH MEMORY – ENDURANCE: 1000 WRITE/ERASE CYCLES • 4.0V TO 5.5V OPERATING RANGE • FULLY STATIC OPERATION: 0 HZ TO 33 MHZ • THREE-LEVEL PROGRAM MEMORY LOCK • 256 X 8-BIT INTERNAL RAM • 32 PROGRAMMABLE I/O LINES
- 24. 24 • THREE 16-BIT TIMER/COUNTERS • EIGHT INTERRUPT SOURCES • FULL DUPLEX UART SERIAL CHANNEL • LOW-POWER IDLE AND POWER-DOWN MODES • INTERRUPT RECOVERY FROM POWER-DOWN MODE • WATCHDOG TIMER • DUAL DATA POINTER • POWER-OFF FLAG 3.3 Pin Configuration: FIG NO 3.1
- 25. 25 3.4 A BRIEF HISTORY OF 8051 In 1981, Intel Corporation introduced an 8 bit microcontroller called 8051. This microcontroller had 128 bytes of RAM, 4K bytes of chip ROM, two timers, one serial port, and four ports all on a single chip. At the time it was also referred as “A SYSTEM ON A CHIP” 3.4.1 AT89S52: The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8K bytes of in-system programmable Flash memory. The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard 80C51 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 in- system programmable Flash on a monolithic chip, the Atmel AT89S52 is a powerful micro- controller, which provides a highly flexible and cost-effective solution to many, embedded control applications. The AT89S52 provides the following standard features: 8K bytes of Flash, 256 bytes of RAM, 32 I/O lines, Watchdog timer, two data pointers, three 16-bit timer/counters, a six-vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator, and clock circuitry. In addition, the AT89S52 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port, and interrupt system to continue functioning. The Power-down mode saves the RAM con-tents but freezes the oscillator, disabling all other chip functions until the next interrupt FIG 3.2 (AT89S52)
- 26. 26 FIG 3.3 MICRO CONTROLLER BLOCK DIAGRAM 8031 has 128 bytes of RAM, two timers and 6 interrupts. 8051 has 4K ROM, 128 bytes of RAM, two timers and 6 interrupts. 8052 has 8K ROM, 256 bytes of RAM, three timers and 8 interrupts. Of the three microcontrollers, 8051 is the most preferable. Microcontroller supports both serial and parallel communication. In the concerned project 8052 microcontroller is used. Here microcontroller used is AT89S52, which is manufactured by ATMEL laboratories. The 8051 is the name of a big family of microcontrollers. The device which we are going to use along this tutorial is the 'AT89S52' which is a typical 8051 microcontroller manufactured by Atmel™. Note that this part doesn't aim to explain the functioning of the different components of a 89S52 microcontroller, but rather to give you a general idea of the organization of the chip and the available features, which shall be explained in detail along this tutorial. The block diagram provided by Atmel™ in their datasheet showing the architecture the 89S52
- 27. 27 device can seem very complicated, and since we are going to use the C high level language to program it, a simpler architecture can be represented as the figure 1.2.A. This figure shows the main features and components that the designer can interact with. You can notice that the 89S52 has 4 different ports, each one having 8 Input/output lines providing a total of 32 I/O lines. Those ports can be used to output DATA and orders do other devices, or to read the state of a sensor, or a switch. Most of the ports of the 89S52 have 'dual function' meaning that they can be used for two different functions: the fist one is to perform input/output operations and the second one is used to implement special features of the microcontroller like counting external pulses, interrupting the execution of the program according to external events, performing serial data transfer or connecting the chip to a computer to update the software. 3.4.2 Introduction to AT89S52 The system requirements and control specifications clearly rule out the use of 16, 32 or 64 bit micro controllers or microprocessors. Systems using these may be earlier to implement due to large number of internal features. They are also faster and more reliable but, the above application is satisfactorily served by 8-bit micro controller. Using an inexpensive 8-bit Microcontroller will doom the 32-bit product failure in any competitive market place. Coming to the question of why to use 89S52 of all the 8-bit Microcontroller available in the market the main answer would be because it has 8kB Flash and 256 bytes of data RAM32 I/O lines, three 16-bit timer/counters, a Eight-vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator, and clock circuitry. In addition, the AT89S52 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port, and interrupt system to continue functioning. The Power down Mode saves the RAM contents but freezes the oscillator, disabling all other chip functions until the next hardware reset. The Flash program memory supports both parallel programming and in Serial In-System Programming (ISP). The 89S52 is also In- Application Programmable (IAP), allowing the Flash program memory to be reconfigured even while the application is running.
- 28. 28 By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89S52 is a powerful microcomputer which provides a highly flexible and cost effective solution to many embedded control applications. Features Compatible with MCS-51 Products 8K Bytes of In-System Reprogrammable Flash Memory Fully Static Operation: 0 Hz to 33 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 4.0V to 5.5V Operating Range Full Duplex UART Serial Channel Interrupt Recovery from Power-down Mode Watchdog Timer Dual Data Pointer Power-off Flag Fast Programming Time Flexible ISP Programming (Byte and Page Mode)
- 29. 29 3.4.3 PIN DIAGRAM FIG-3.4 PIN DIAGRAM OF 89S52 IC 3.4.4PIN DESCRIPTION Pin Description VCC: Supply voltage. GND: Ground Port 0 Port 0 is an 8-bit open drain bidirectional I/O port. As an output port, each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as high impedance inputs. Port 0 can also be configured to be the multiplexed low order address/data bus during accesses to external program and data memory. In this mode, P0 has internal pull-ups. Port 0 also receives the code bytes during Flash programming and outputs the code bytes during program verification.External pull-ups are required during program verification. Port 1
- 30. 30 Port 1 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 1 output buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins, they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pull-ups. In addition, P1.0 and P1.1 can be configured to be the timer/counter 2 external count input (P1.0/T2) and the timer/counter 2 trigger input (P1.1/T2EX), respectively, as shown in the following table. Port 1 also receives the low-order address bytes during Flash programming and verification. TABLE 3.1 Port 2 Port 2 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 2 output buffers can sink/source four TTL inputs. When 1s are written to Port 2 pins, they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 2 pins that are externally being pulled low will source current (IIL) because of the internal pull-ups. Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that uses 16-bit addresses (MOVX @ DPTR). In this application, Port 2 uses strong internal pull-ups when emitting 1s. During accesses to external data memory that uses 8-bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function Register. Port 2 also receives the high-order address bits and some control signals during Flash programming and verification. Port 3 Port 3 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 3 output buffers can sink/source four TTL inputs. When 1s are written to Port 3 pins, they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current (IIL) because of the pull-ups. Port 3 also serves the functions of various
- 31. 31 special features of the AT89S52, as shown in the following table. Port 3 also receives some control signals for Flash programming and verification. TABLE 3.2 RST Reset input. A high on this pin for two machine cycles while the oscillator is running resets the device. This pin drives High for 96 oscillator periods after the Watchdog times out. The DISRTO bit in SFR AUXR (address 8EH) can be used to disable this feature. In the default state of bit DISRTO, the RESET HIGH out feature is enabled. ALE/PROG Address Latch Enable (ALE) is an output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming. In normal operation, ALE is emitted at a constant rate of 1/6 the oscillator frequency and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during each access to external data memory. If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode. PSEN Program Store Enable (PSEN) is the read strobe to external program memory. When the AT89S52 is executing code from external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory. EA/VPP External Access Enable. EA must be strapped to GND in order to enable the device to fetch code from external program memory locations starting at 0000H up to FFFFH. Note,
- 32. 32 however, that if lock bit 1 is programmed, EA will be internally latched on reset. EA should be strapped to VCC for internal program executions. This pin also receives the 12-volt programming enable voltage (VPP) during Flash programming. XTAL1 Input to the inverting oscillator amplifier and input to the internal clock operating circuit. XTAL2: Output from the inverting oscillator amplifier. FIG-3.5 Functional block diagram of micro controller The 8052 Oscillator and Clock: The heart of the 8051 circuitry that generates the clock pulses by which all the internal all internal operations are synchronized. Pins XTAL1 And XTAL2 is provided for connecting a resonant network to form an oscillator. Typically a quartz crystal and capacitors are employed. The crystal frequency is the basic internal clock frequency of the microcontroller. The manufacturers make 8051 designs that run at specific minimum and maximum frequencies typically 1 to 16 MHz
- 33. 33 Fig-3.6 Oscillator and timing circuit
- 34. 34 CHAPTER 4 HT 12E ENCODER 4.1 Features Operating voltage 2.4V~5V for the HT12A 2.4V~12V for the HT12E Low power and high noise immunity CMOS technology Low standby current: 0.1_A (typ.) at VDD=5V HT12A with a 38kHz carrier for infrared transmission medium Minimum transmission word Four words for the HT12E Built-in oscillator needs only 5% resistor Data code has positive polarity Minimal external components HT12E: 18-pin DIP FIG 4.1 4.2 Applications Burglar alarm system Smoke and fire alarm system Garage door controllers Car door controllers Car alarm system Security system
- 35. 35 Cordless telephones Other remote control systems 4.3 General Description The 212 encoders are a series of CMOS LSIs for remote control system applications. They are capable of encoding information which consists of N address bits and 12_N data bits. Each address/ data input can be set to one of the two logic states. The programmed addresses/data are transmitted together with the header bits via an RF or an infrared transmission medium upon receipt of a trigger signal. The capability to select a TE trigger on the HT12E or a DATA trigger on the HT12A further enhances the application flexibility of the 212 series of encoders. The HT12A additionally provides a 38kHz carrier for infrared systems. FIG 4.2
- 36. 36 TABLE NO 4.1 TABLE NO 4.2
- 37. 37 FIG 4.3 Absolute Maximum Ratings Supply Voltage (HT12A) .............._0.3V to 5.5V Supply Voltage (HT12E) ..............._0.3V to 13V Input Voltage....................VSS_0.3 to VDD+0.3V Storage Temperature................._50_C to 125_C Operating Temperature..............._20_C to 75_C Note: These are stress ratings only. Stresses exceeding the range specified under Absolute Maximum Ratings may cause substantial damage to the device. Functional operation of this device at other conditions beyond those listed in the specification is not implied and prolonged exposure to extreme conditions may affect device reliability. Features Operating voltage: 2.4V~12V
- 38. 38 Low power and high noise immunity CMOS Technology Low standby current Capable of decoding 12 bits of information Binary address setting Received codes are checked 3 times Address/Data number combination HT12D: 8 address bits and 4 data bits HT12F: 12 address bits only Built-in oscillator needs only 5% resistor valid transmission indicator Easy interface with an RF or an infrared transmission medium Minimal external components Pair with Holtek_s 212 series of encoders 18-pin DIP, 20-pin SOP package Applications Burglar alarm system Smoke and fire alarm system Garage door controllers Car door controllers Car alarm system Security system Cordless telephones
- 39. 39 CHAPTER 5 433 MHZ RF TRANSMITTER STT-433 5.1 Overview The STT-433 is ideal for remote control applications where low cost and longer range is required. The transmitter operates from a1.5-12V supply, making it ideal for battery-powered applications. The transmitter employs a SAW-stabilized oscillator, ensuring accurate frequency control for best range performance. Output power and harmonic emissions are easy to control, making FCC and ETSI compliance easy. The manufacturing-friendly SIP style package and low- cost make the STT-433 suitable for high volume applications. FIG 5.1 5.2 Features · 433.92 MHz Frequency · Low Cost · 1.5-12V operation · 11mA current consumption at 3V
- 40. 40 · Small size · 4 dBm output power at 3V 3. Applications Remote Keyless Entry (RKE) Remote Lighting Controls On-Site Paging Asset Tracking Wireless Alarm and Security Systems Long Range RFID Automated Resource Management Table No 5.1 Table No 5.2
- 41. 41 5.3 OPERATION Theory OOK(On Off Keying) modulation is a binary form of amplitude modulation. When a logical 0 (data line low) is being sent, the transmitter is off, fully suppressing the carrier. In this state, the transmitter current is very low, less than 1mA. When a logical 1 is being sent, the carrier is fully on. In this state, the module current consumption is at its highest, about 11mA with a 3V power supply. OOK is the modulation method of choice for remote control applications where power consumption and cost are the primary factors. Because OOK transmitters draw no power when they transmit a 0, they exhibit significantly better power consumption than FSK transmitters. OOK data rate is limited by the start-up time of the oscillator. High-Q oscillators which have very stable center frequencies take longer to start-up than low-Q oscillators. The start-up time of the oscillator determines the maximum data rate that the transmitter can send. Data Rate The oscillator start-up time is on the order of 40uSec, which limits the maximum data rate to 4.8 kbit/sec. SAW stabilized oscillator The transmitter is basically a negative resistance LC oscillator whose center frequency is tightly controlled by a SAW resonator. SAW (Surface Acoustic Wave) resonators are fundamental frequency devices that resonate at frequencies much higher than crystals. Typical Application Remark: Antenna length about: 17cm for 433MHz
- 42. 42 CHAPTER 6 433 MHZ RF RECEIVER STR-433 6.1 Overview The STR-433 is ideal for short-range remote control applications where cost is a primary concern. The receiver module requires no external RF components except for the antenna. It generates virtually no emissions, making FCC and ETSI approvals easy. The super-regenerative design exhibits exceptional sensitivity at a very low cost. The manufacturing-friendly SIP style package and low-cost make the STR-433 suitable for high volume applications. FIG 6.1 6.2 Features · Low Cost · 5V operation · 3.5mA current drain · No External Parts are required · Receiver Frequency: 433.92 MHZ · Typical sensitivity: -105dBm · IF Frequency: 1MHz 6.3 Applications · Car security system · Sensor reporting
- 43. 43 · Automation system · Remote Keyless Entry (RKE) · Remote Lighting Controls · On-Site Paging · Asset Tracking · Wireless Alarm and Security Systems · Long Range RFID · Automated Resource Management TABLE 6.1 FIG NO & TABLE NO 6.2
- 44. 44 CHAPTER 7 RELAYS SPDT FIG 7.1 7.1 Overview OF Relays A relay is an electrically operated switch used to isolate one electrical circuit from another. In its simplest form, a relay consists of a coil used as an electromagnet to open and close switch contacts. Since the two circuits are isolated from one another, a lower voltage circuit can be used to trip a relay, which will control a separate circuit that requires a higher voltage or amperage. Relays can be found in early telephone exchange equipment, in industrial control circuits, in car audio systems, in automobiles, on water pumps, in high-power audio amplifiers and as protection devices. Relay Switch Contacts The switch contacts on a relay can be "normally open" (NO) or "normally closed" (NC)--that is, when the coil is at rest and not energized (no current flowing through it), the switch contacts are given the designation of being NO or NC. In an open circuit, no current flows, such as a wall light switch in your home in a position that the light is off. In a closed circuit, metal switch contacts touch each other to complete a circuit, and current flows, similar to turning a light switch to the "on" position. In the accompanying schematic diagram, points A and B connect to the coil. Points C and D connect to the FIG NO 7.2
- 45. 45 switch. When you apply a voltage across the coil at points A and B, you create an electromagnetic field, which attracts a lever in the switch, causing it to make or break contact in the circuit at points C and D (depending if the design is NO or NC). The switch contacts remain in this state until you remove the voltage to the coil. Relays come in different switch configurations. The switches may have more than one "pole," or switch contact. The diagram shows a "single pole single throw" configuration, referred to as SPST. This is similar to a wall light switch in your home. With a single "throw" of the switch, you close the circuit. The Single Pole Double Throw Relay A single pole double throw (SPDT) relay configuration switches one common pole to two other poles, flipping between them. As shown in the schematic diagram, the common point E completes a circuit with C when the relay coil is at rest, that is, no voltage is applied to it. FIG NO 7.3 This circuit is "closed." A gap between the contacts of point E and D creates an "open" circuit. When you apply power to the coil, a metal level is pulled down, closing the circuit between points E and D and opening the circuit between E and C. A single pole double throw relay can be used to alternate which circuit a voltage or signal will be sent to. SPDT Relay: (Single Pole Double Throw Relay) an electromagnetic switch, consist of a coil (terminals 85 & 86), 1 common terminal (30), 1 normally closed terminal (87a), and one normally open terminal (87) (Figure 1). When the coil of an SPDT relay (Figure 1) is at rest (not energized), the common terminal (30) and the normally closed terminal (87a) have continuity. When the coil is energized, the common terminal (30) and the normally open terminal (87) have continuity. The diagram below center (Figure 2) shows an SPDT relay at rest, with the coil not energized.
- 46. 46 The diagram below right (Figure 3) shows the relay with the coil energized. As you can see, the coil is an electromagnet that causes the arm that is always connected to the common (30) to pivot when energized whereby contact is broken from the normally closed terminal (87a) and made with the normally open terminal (87). When energizing the coil of a relay, polarity of the coil does not matter unless there is a diode across the coil. If a diode is not present, you may attach positive voltage to either terminal of the coil and negative voltage to the other, otherwise you must connect positive to the side of the coil that the cathode side (side with stripe) of the diode is connected and negative to side of the coil that the anode side of the diode is connected. FIG 7.4 FIG 7.5 FIG 7.6 Why do I want to use a relay and do I really need to? Anytime you want to switch a device which draws more current than is provided by an output of a switch or component you'll need to use a relay. The coil of an SPDT or an SPST relay that we most commonly use draws very little current (less than 200 milliamps) and the amount of current
- 47. 47 that you can pass through a relay's common, normally closed, and normally open contacts will handle up to 30 or 40 amps. This allows you to switch devices such as headlights, parking lights, horns, etc., with low amperage outputs such as those found on keyless entry and alarm systems, and other components. In some cases you may need to switch multiple things at the same time using one output. A single output connected to multiple relays will allow you to open continuity and/or close continuity simultaneously on multiple wires. There are far too many applications to list that require the use of a relay, but we do show many of the most popular applications in the pages that follow and many more in our Relay Diagrams - Quick Reference application. If you are still unclear about what a relay does or if you should use one after you browse through the rest of this section, please post a question in the12volt's install bay. (We recommend Tyco (formerly Bosch) or Potter & Brumfield relays for all of the SPDT and SPST relay applications shown on this site.) FIG 7.7
- 48. 48 CHAPTER 8 ULN2003 ULN is mainly suited for interfacing between low-level circuits and multiple peripheral power loads,.The series ULN20XX high voltage, high current darlington arrays feature continuous load current ratings. The driving circuitry in- turn decodes the coding and conveys the necessary data to the stepper motor, this module aids in the movement of the arm through steppers FIG 8.1 FIG 8.2
- 49. 49 The driver makes use of the ULN2003 driver IC, which contains an array of 7 power Darlington arrays, each capable of driving 500mA of current. At an approximate duty cycle, depending on ambient temperature and number of drivers turned on, simultaneously typical power loads totaling over 230w can be controlled.The device has base resistors, allowing direct connection to any common logic family. All the emitters are tied together and brought out to a separate terminal. Output protection diodes are included; hence the device can drive inductive loads with minimum extra components. Typical loads include relays, solenoids, stepper motors, magnetic print hammers, multiplexed LED, incandescent displays and heaters. 8.1 Darlington Pair hat is a Darlington Pair? A Darlington pair is two transistors that act as a single transistor but with a much higher current gain. What is current gain? Transistors have a characteristic called current gain. This is referred to as its hFE. The amount of current that can pass through the load when connected to a transistor that is turned on equals the input current x the gain of the transistor (hFE) The current gain varies for different transistor and can be looked up in the data sheet for the device. Typically it may be 100. This would mean that the current available to drive the load would be 100 times larger than the input to the transistor. FIG 8.3
- 50. 50 CHAPTER 9 GEAR MOTOR What Is a Gear Motor? Gear motors are complete motive force systems consisting of an electric motor and a reduction gear train integrated into one easy-to-mount and -configure package. This greatly reduces the complexity and cost of designing and constructing power tools, machines and appliances calling for high torque at relatively low shaft speed or RPM. Gear motors allow the use of economical low-horsepower motors to provide great motive force at low speed such as in lifts, winches, medical tables, jacks and robotics. They can be large enough to lift a building or small enough to drive a tiny clock. . FIG 9.1 12V High Torque DC GEAR MOTOR FIG 9.2
- 51. 51 9.1 Operation Principle Most synchronous AC electric motors have output ranges of from 1,200 to 3,600 revolutions per minute. They also have both normal speed and stall-speed torque specifications. The reduction gear trains used in gear motors are designed to reduce the output speed while increasing the torque. The increase in torque is inversely proportional to the reduction in speed. Reduction gearing allows small electric motors to move large driven loads, although more slowly than larger electric motors. Reduction gears consist of a small gear driving a larger gear. There may be several sets of these reduction gear sets in a reduction gear box. 9.1.1 Gear Toothed wheel that transmits the turning movement of one shaft to another shaft. Gear wheels may be used in pairs or in threes if both shafts are to turn in the same direction. The gear ratio – the ratio of the number of teeth on the two wheels – determines the torque ratio, the turning force on the output shaft compared with the turning force on the input shaft. The ratio of the angular velocities of the shafts is the inverse of the gear ratio. The common type of gear for parallel shafts is the spur gear, with straight teeth parallel to the shaft axis. The helical gear has teeth cut along sections of a helix or corkscrew shape; the double form of the helix gear is the most efficient for energy transfer. Bevel gears, with tapering teeth set on the base of a cone, are used to connect intersecting shafts. FIG 9.3
- 52. 52 FIG 9.4 The toothed and interlocking wheels which make up a typical gear movement. Gear ratio is calculated by dividing the number of teeth on the driver gear by the number of teeth on the driven gear (gear ratio = driver/driven); the idler gears are ignored. Idler gears change the direction of rotation but do not affect speed. A high driven to driver ratio (middle) is a speed- reducing ratio. FIG 9.5 Different gears are used to perform different engineering functions depending on the change in direction of motion that is needed. Rack and pinion gears are the commonest gears and are used in car steering mechanics. 9.2 Speed Reduction Sometimes the goal of using a gear motor is to reduce the rotating shaft speed of a motor in the device being driven, such as in a small electric clock where the tiny synchronous motor may be spinning at 1,200 rpm but is reduced to one rpm to drive the second hand, and further reduced in the clock mechanism to drive the minute and hour hands. Here the amount of driving force is irrelevant as long as it is sufficient to overcome the frictional effects of the clock mechanism. 9.3 Torque Multiplication Another goal achievable with a gear motor is to use a small motor to generate a very large force albeit at a low speed. These applications include the lifting mechanisms on hospital beds, power recliners, and heavy machine lifts where the great force at low speed is the goal.
- 53. 53 Motor Varieties Most industrial gear motors are AC-powered, fixed-speed devices, although there are fixed-gear-ratio, variable-speed motors that provide a greater degree of control. DC gear motors are used primarily in automotive applications such as power winches on trucks, windshield wiper motors and power seat or power window motors. 9.4 Applications What power can openers, garage door openers, stair lifts, rotisserie motors, timer cycle knobs on washing machines, power drills, cake mixers and electromechanical clocks have in common is that they all use various integrations of gear motors to derive a large force from a relatively small electric motor at a manageable speed. In industry, gear motor applications in jacks, cranes, lifts, clamping, robotics, conveyance and mixing are too numerous to count.
- 54. 54 CHAPTER 10 REGULATED POWER SUPPLY The power supplies are designed to convert high voltage AC mains electricity to a suitable low voltage supply for electronics circuits and other devices. A RPS (Regulated Power Supply) is the Power Supply with Rectification, Filtering and Regulation being done on the AC mains to get a Regulated power supply for Microcontroller and for the other devices being interfaced to it. A power supply can by broken down into a series of blocks, each of which performs a particular function. A d.c power supply which maintains the output voltage constant irrespective of a.c mains fluctuations or load variations is known as “Regulated D.C Power Supply” For example a 5V regulated power supply system as shown below: FIG 10.1
- 55. 55 10.1 Transformer: A transformer is an electrical device which is used to convert electrical power from one Electrical circuit to another without change in frequency. Transformers convert AC electricity from one voltage to another with little loss of power. Transformers work only with AC and this is one of the reasons why mains electricity is AC. Step- up transformers increase in output voltage, step-down transformers decrease in output voltage. Most power supplies use a step-down transformer to reduce the dangerously high mains voltage to a safer low voltage. The input coil is called the primary and the output coil is called the secondary. There is no electrical connection between the two coils; instead they are linked by an alternating magnetic field created in the soft-iron core of the transformer. The two lines in the middle of the circuit symbol represent the core. Transformers waste very little power so the power out is (almost) equal to the power in. Note that as voltage is stepped down current is stepped up. The ratio of the number of turns on each coil, called the turn’s ratio, determines the ratio of the voltages. A step-down transformer has a large number of turns on its primary (input) coil which is connected to the high voltage mains supply, and a small number of turns on its secondary (output) coil to give a low output voltage. An Electrical Transformer FIG 10.2
- 56. 56 Turns ratio = Vp/ VS = Np/NS Power Out= Power In VS X IS=VP X IP Vp = primary (input) voltage Np = number of turns on primary coil Ip = primary (input) current 10.2 RECTIFIER: A circuit which is used to convert a.c to dc is known as RECTIFIER. The process of conversion a.c to d.c is called “rectification” Parameter Type of Rectifier Half wave Full wave Bridge Number of diodes 1 2 4 PIV of diodes Vm 2Vm Vm D.C output voltage Vm/ 2Vm/ 2Vm/ Vdc,at no-load 0.318Vm 0.636Vm 0.636Vm Ripple factor 1.21 0.482 0.482 Ripple frequency f 2f 2f Rectification efficiency 0.406 0.812 0.812
- 57. 57 TABLE NO 10.1 10.2.1 TYPES OF RECTIFIERS: Half wave Rectifier Full wave rectifier 1. Centre tap full wave rectifier. 2. Bridge type full bridge rectifier. 10.2.1.1Comparison of rectifier circuits: Full-wave Rectifier From the above comparison we came to know that full wave bridge rectifier as more advantages than the other two rectifiers. So, in our project we are using full wave bridge rectifier circuit. Bridge Rectifier A bridge rectifier makes use of four diodes in a bridge arrangement to achieve full-wave rectification. This is a widely used configuration, both with individual diodes wired as shown and with single component bridges where the diode bridge is wired internally. A bridge rectifier makes use of four diodes in a bridge arrangement as shown in fig (a) to achieve full-wave rectification. This is a widely used configuration, both with individual diodes wired as shown and with single component bridges where the diode bridge is wired internally. Transformer Utilization Factor(TUF) 0.287 0.693 0.812 RMS voltage Vrms Vm/2 Vm/√2 Vm/√2
- 58. 58 Fig 10.3 10.3 Operation: During positive half cycle of secondary, the diodes D2 and D3 are in forward biased while D1 and D4 are in reverse biased as shown in the fig(b). The current flow direction is shown in the fig (b) with dotted arrows. Fig 10.4 During negative half cycle of secondary voltage, the diodes D1 and D4 are in forward biased while D2 and D3 are in reverse biased as shown in the fig(c). The current flow direction is shown in the fig (c) with dotted arrows.
- 59. 59 Fig 10.5 10.4 Filter: A Filter is a device which removes the a.c component of rectifier output but allows the d.c component to reach the load 10.5 Capacitor Filter: We have seen that the ripple content in the rectified output of half wave rectifier is 121% or that of full-wave or bridge rectifier or bridge rectifier is 48% such high percentages of ripples is not acceptable for most of the applications. Ripples can be removed by one of the following methods of filtering. A capacitor, in parallel to the load, provides an easier by –pass for the ripples voltage though it due to low impedance. At ripple frequency and leave the D.C. to appear at the load. An inductor, in series with the load, prevents the passage of the ripple current (due to high impedance at ripple frequency) while allowing the d.c (due to low resistance to d.c) Various combinations of capacitor and inductor, such as L-section filter section filter, multiple section filter etc. which make use of both the properties mentioned in (a) and (b) above. Two cases of capacitor filter, one applied on half wave rectifier and another with full wave rectifier.
- 60. 60 Filtering is performed by a large value electrolytic capacitor connected across the DC supply to act as a reservoir, supplying current to the output when the varying DC voltage from the rectifier is falling. The capacitor charges quickly near the peak of the varying DC, and then discharges as it supplies current to the output. Filtering significantly increases the average DC voltage to almost the peak value (1.4 × RMS value). To calculate the value of capacitor(C), C = ¼*√3*f*r*Rl Where, f = supply frequency, r = ripple factor, Rl = load resistance Note: In our circuit we are using 1000µF hence large value of capacitor is placed to reduce ripples and to improve the DC component. 10.6 Regulator: Voltage regulator ICs is available with fixed (typically 5, 12 and 15V) or variable output voltages. The maximum current they can pass also rates them. Negative voltage regulators are available, mainly for use in dual supplies. Most regulators include some automatic protection from excessive current ('overload protection') and overheating ('thermal protection'). Many of the fixed voltage regulators ICs have 3 leads and look like power transistors, such as the 7805 +5V 1A regulator shown on the right. The LM7805 is simple to use. You simply connect the positive lead of your unregulated DC power supply (anything from 9VDC to 24VDC) to the Input pin, connect the negative lead to the Common pin and then when you turn on the power, you get a 5 volt supply from the output pin.
- 61. 61 Fig 10.6 Three Terminal Voltage Regulator 78XX: The Bay Linear LM78XX is integrated linear positive regulator with three terminals. The LM78XX offer several fixed output voltages making them useful in wide range of applications. When used as a zener diode/resistor combination replacement, the LM78XX usually results in an effective output impedance improvement of two orders of magnitude, lower quiescent current. The LM78XX is available in the TO-252, TO-220 & TO-263packages, 10.7 Features: • Output Current of 1.5A • Output Voltage Tolerance of 5% • Internal thermal overload protection • Internal Short-Circuit Limited • Output Voltage 5.0V, 6V, 8V, 9V, 10V, 12V, 15V, 18V, 24V.
- 62. 62 CHAPTER 11 HARDWARE CONFIGURATION 11.1 Wireless Camera: Smallest wireless video and audio camera in the world super mini type for surveillance attached with a dc stepper motor; it acts as a 360’ acting type for search and support. With an audio and video radio frequency module it gives a large variety of support towards a high megapixel clarity interchange. A receiver is to be attached to a laptop or a pc and transmitter is attached already with the camera hence receiving and transmitting live feed from the surroundings. Fig 11.1 11.2 The Chassis: The chassis has been designed in such a way that the robot can easily climb an obstacle with several calculations for balancing considering the centre of gravity. Center of gravity is the point in a body around which the resultant torque due to gravity forces vanishes. Near the surface of the earth, where the gravity acts downward as a parallel force field, the center of gravity and the center of mass are the same.
- 63. 63 An experimental method to locate the three-dimensional coordinates of the center of mass begins by supporting the object at three points and measuring the forces, F1, F2, and F3 that resist the weight of the object. An experimental method for locating the center of mass is to suspend the object from two locations and to drop plumb lines from the suspension points. The intersection of the two lines is the center of mass The shape of an object might already be mathematically determined, but it may be too complex to use a known formula. In this case, one can subdivide the complex shape into simpler, more elementary shapes, whose centers of mass are easy to find. If the total mass and center of mass can be determined for each area, then the center of mass of the whole is the weighted average of the centers. This method can even work for objects with holes, which can be accounted for as negative masses. Lathe machine operations such as drilling, boring, grinding, welding, shaping have been done in order to make the chassis Fig 11.2
- 64. 64 11.3 Anti CorrosionPaint: Anti corrosion paint has been applied so as to reduce the corrosion factor as the chassis is made of iron and may corrode under circumstances. Anti-corrosion refers to the protection of metal surfaces from corroding in high-risk (corrosive) environments. When metallic materials are put into corrosive environments, they tend to have chemical reactions with the air and/or water. The effects of corrosion become evident on the surfaces of these materials. For example, after putting the iron into a corrosive atmosphere for an extended period, the iron starts rusting due to oxygen interaction with water on the iron's surface. Therefore, metal equipment lacking any preventive (anti-corrosive) measures, may become rusted both inside and out, depending upon atmospheric conditions and how much of that equipment is exposed to the air. There are a number of methods for preventing corrosion, especially in marine applications. Anti-corrosion measures are of particular importance in environments where high humidity, mist, and salt are factors.
- 65. 65 CHAPTER 12 12.1 Advantages: Reduce risk of human Lives By exchanging places. Constant Surveillance under Threat. Reduces man power Can be used in highly polluted environment where man cannot go. 12.2 Applications: Border security Regular surveillance Internal security 12.3 Future Scope & Aspects: For further development of this project we can add ultrasonic sensors and stair climbing mechanisms for evaluation of distances and increased standard of low profile surveillance.
- 66. 66 CONCLUSION We conclude that with the use of this project we intend to reduce the risk of lives as well as increase the border security and internal security in cities by constantly evaluating the surrounding areas without disturbing the harmony of people, and high surveillance can be monitored. It has been developed by integrating features of all hardware and software components used. .
- 67. 67 REFERENCES www.instructables.com www.robotshop.com www.societyofrobots.com/step_by_step_robot.shtml electronics.howstuffworks.com/microcontroller.htm LEGO MIND STORMS (LAURENS VOLK)