The Smart Metal Detector

The Smart Metal demodulatorThis expulsion is the combination of hardw atomic number 18 and softw atomic number 18 product. With the aid of the micro-controller, this surface sensor apprize substantiate more useful function. This system consists of 3 main parts of hardwargonThe construction of smart admixture sensing element indispensable the gathering of in normalation/ intimacy/ concepts of restraint sensor, liquid crystal display Display, H-Bridge DC motor number one wood, PIC micro-controller, surface sensor technology and so on. Besides that, some knowledge in softw atomic number 18 part PIC Assembly language and other useful software MPLAB, Protel XP, and multisim are also privationed.Nowadays, Metal detectors have stick a very common staple in todays society and widely used in human live in a range of usage from empty to go away and also safety purpose. For Safety purpose, Metal detector that used in airport to ensure that there is no dangerous weapon such a s knives, guns or whatever metal fair games that could be used as weapons has been brought along by terrorist into the airplane. In technical area, people used metal detector to search for the underground pipe or cable before digging in walls and floors. Besides that, legion(predicate) people enjoy in discovering hidden view or valuable metal like gold and silver by using metal detector.Metal detector products are available in market. It has many types of metal detectors are sold which used in antithetic area. However, many of them have the following dis favoursExpensiveThe prices of metal detectors are very pricy. Although the more expensive metal detector has higher performance and functionality, usually we dont need so much of the function. The extra function that we dont need result be wasted. So the prices of metal detector products that sold in market wouldnt be afford by everyone.Manually controlled metal detectorMany of the metal detectors are manually controlled by h uman where exploiters are necessitate to handle it and walk around to detect the underground metal. This is very exhausted and tired work.Based on these devil disadvantages, users need a low address and have basic function of mobility metal detector. The smart metal detector is a device that used to detect tinny material such as coins, gold and other metal items. It can move and change the direction of movement in certain situation to descry the underground metal. It willing take a U turn when it reached the desired distance which already represent inside the microcontroller and continue move in some other track. It will avoid the obstacle with the help of sensor. When it detects a metal, it will puke on alarm to indicate user.2.0 Statement of AimsBelow are the aims that targeted to achieve in the Smart metal detector projectAutomatic movementIn this section, the concept of relationship between H-Bridge driver and DC motors are utilize into the project. The H-Bridge drive r is a tour of duty that used to control the direction of DC motors with the help of micro-controller.Obstacle avoidanceWhen the device has detected an obstacle block in crusade of the metal detector, it will avoid the obstacle automatically by changing its movement direction to prevent collision happened.Micro-controller applicationA micro-controller is used to become the main brain of the mobile metal detector. The main purpose of the micro-controller is used to give instruction to control all the function of the metal detection.Alarm beep when detect metalWhen the metal detector has been detected underground metal, the buzzer will beep on to inform users that some metal elements have been detected.liquid crystal display display indicationAll the status and message from the metal detector are indicating in the LCD display. For example, the message of Metal Found will be shown in LCD when the metal detector has been detected metal element.3.0 ObjectiveThe main intentionive of t his project is to develop a Smart Metal Detector into more automation area. With the automation of metal detector, this concept will be contributed to the real life application.The sub-objectives of this project will be elaborate belowTo curb the electric and electronic knowledge that I have learned into the real application issue.To provide a low cost metal detector for familiar metal detection purpose.To learn the skill of writing software in PIC Assembly language.To learn the skill of debugging the software problems or bugs.To learn how to work followed the planned schedule, as well as the Gantt Chart.4.0 Literature ReviewThe first person that invented the first crude metal detector in 1881 was Alexander whole meal flour Bell. After that, the metal detector concept has been kept on improving to become more advance and applicable in various areas.Basically, there are three technologies used in metal detectors. These three technologies are I. Very Low Frequency (VLF) technolog yII. Pulse Induction (PI) TechnologyIII. Beat-Frequency Oscillation (BFO) TechnologyVLF is known as induction balance and it is also the most popular metal detector technology used nowadays. There are two distinct pealings that used in a VLF metal detector, transmitter coil and recipient coil. The transmitter coil is the outer coil loop which is turn with wire. Electricity is being sent along the wire and creates the electromagnetic field. The receiver coil is the inner coil loop which is also coiled with another wire. The receiver coil acts as an antenna to pick up and amplify the frequencies which come from the target metallic objects in the ground.The metal detector has the ability to determine well-nigh the deeper of the targeted buried object. This can be done by determine the strength of the magnetic field that the object generates. The concept is very simple The stronger magnetic field will be detected if the metal detector is closer to the surface of the targeted object. Alternately, the further the object away from the metal detector, the weaker the magnetic field will be detected.The metal detector also can contraryial the types of metals. It is relied on a phenomenon called as phase shifting. The differences in timing between the frequencies of transmitter coil and the targeted object is called phase shift. For example, an object with high inductance will have a larger phase shift because it takes longer time to alter its magnetic field. However, an object with high resistance will have a small phase shift. The phase shift concept provided VLF based metal detector has the qualification called discrimination. The metal detector used a pair of electronic circuits called phase demodulators to compare the phase shift of target object with the average of a ill-tempered type of metal to examine the metal class of the target object. The detector will hence notifies user with perceptible tone or visual index finger of what class of the metal is mos t likely to be. The phase shift concept also allowed user to filter out (discriminate) the unwanted object above a certain phase-shift level.Pulse Induction (PI) technology is a less common form of the metal detector. PI metal detector uses only single coil as both transmitter and receiver, or using 2 or 3 coils work together. The metal detector sends powerful, short pulses of current through a coil of wire. This cause each pulse generates a brief magnetic field. The magnetic field will reverse polarity and collapses very suddenly after the pulse ends and causing a sharp electrical spike. After the spikes, a current called reflected pulse will run through another coil and this surgery will keep on repeating in very short time. The PI based metal detector works like echoes If the metal detector is over a metallic object, an opposite magnetic field will create by the pulse in the object. After the collapsing of the pulses magnetic field, the reflected pulse will be generated, and thu s the magnetic field of the object cause it take longer time for the reflected pulse to disappear absolutely.A sampling circuit is set to monitor the length of the reflected pulse. The circuit can determine if another magnetic field has caused the reflected pulse decay in longer time (usually a few microseconds) than normal, it will suspected that some metallic object is being interfering with it. Usually the sampling circuit is connected to a device called integrator. This integrator can read the received signal from sampling circuit amplifies and converts the signal to direct current (DC). This DCs voltage is connected to an audio circuit which used to indicate the user that targeted object has been detected. This function is almost similar to the VLF based metal detector.PI based metal detector is not as good as VLF based metal detector in discrimination due to the limitation of reflected pulse length of various metals are difficult to separated. However, PI detector is very usef ul to detect object in areas that have highly conductive material such as salt-water exploration. In addition, PI detector has the advantage that can detect metal much deeper in the ground than other systems.Beat-frequency oscillator (BFO) technology is the most basic way that used to detect metal. There are 2 coils of wire in BFO detector. A large coil is in the serarch head and the smaller coil is located inside the control box. Both coils are connected to an oscillator that generates thousands of pulses of current per second. The frequency of the pulses is s faintheartedly offset between two coils. When the search head passes over a metal object, the objects magnetic field will interferes with the frequency of the radio waves which generated by the search head coil. After that, the frequency will deviates from the frequency of the coil in the control box and cause the audible beats change in duration and tone. The BFO detector is sold in low cost compare to other technologies det ector, however, the accuracy and the level of control are not provided.Although there are 3 different of technologies used in metal detector, the basic concept of metal detector can be change as using the coil of wire to detect the magnetic field of the underground metal. Hence send a feedback signal to main circuit or micro-controller to process it.Those metal detectors have various types of function and advance performance however most of them are manually controlled by human. This project is basically applied the technology of metal detector into a more automation field instead of using human control, but not improving of the performance of any market products.5.0 Design MethodologyIn order to complete the project in time, I have separated the whole project progress into some(prenominal) parts. The project development progress is shown in the flowchart formPlanningLiterature researchLiterature Review in background knowledge of metal detector.Information of hardware/components g atheringSoftware skillComponents purchasingHardware constructing (Prototyping)Testing/ExperimentsWriting software (Programming)Modify PrototypesSoftware improvingTestingTroubleshooting/Debugging concluding AssemblingProject Completed6.0 Research and Competitive AnalysisThe hardware part of smart metal detector consists of inputs and outputs. The input parts included obstacle sensor and metal detector circuit. The output parts included H-bridge driver, DC motors and buzzer. A micro-controller is used to interconnect and control the operations among the hardware components. It receives input signals from different inputs and gives the instruction to the outputs based on the situation. The micro-controller will only execute the program that stored inside the memory.Micro-controller works as the brain of the Smart Metal detector. It gets the feedback signal from the sensors/detectors therefore sending signal to control the condition of the H-Bridge driver and turn on the buzzer once m etal is detected.Obstacle Sensor to detect obstacle that blocking in front of the mobile detector to avoid collision happened.Metal detector used to detect the underground metal/mine. The metal detector circuit is uses the coil/inductor to detect the magnetic field of the underground metal. When the coil/inductor cuts the magnetic field of the targeted metal, it will send a feedback signal to the micro-controller.LCD Display can have a better looks and more powerful in showing message instead of using LEDs or Seven-Segments display. It displays the message in the form of alphabet or numbers. So, user will have a better understanding in reading the alphabet message compared to just light on some LEDs.Buzzer/Alarm acts an alarm to warn/inform user that something has happened to the metal detector such as mine has been detected.H-Bridge driver and DC motors used to control the direction of DC motors for different condition such as move forward, stop moving and turning. The DC motors ar e used to prove the wheels of the mobile metal detector.8.0 Software Flow ChartThe programming code is written to interconnect the input hardware and the output hardware. The received signal form inputs will be process in the microcontroller and thus send out the react instruction to the output parts. The PIC assembly language is used in this project.The programs of the basically project can be separated into 3 main partsMain routine of moving.Obstacle avoidance.Metal detected.The estimated cost of this project is to wee a fund which enables us to control the project expenses. For this project, a sum of RM 615 will be allocated to fund the correct project including the hardware and software parts.The cost of the project can be reduced to a certain amount by doing market research and comparing the cost among the vendors. In addition, compare different type of metal detector and obstacle sensor also needed to reduce the project cost. Another alternative is to get second-hand or use d goods in order to minimize the expenditure.Besides this, daily wages must also take into consideration. Considering 400 hours will be utilized to accomplish this project and RM 5 per hour will be paid. Yet another RM 150 is allocated to fund the resources fee such as the electricity and petrol usage. Hence, the overhead cost for this entire project will be charged at RM 2765.11.0 Risk Assessment and ManagementTo complete this project, a few risks that might affect the progress of the project have been drawn out as prevention is better than cure. If there is no other alternative plan has been made or planned now, then it will definitely leave a bad impact to us if this risk does happen. Firstly, in order to make this project a success, intensive learning of assembly language through elongation book and Subject EN0318 Embedded Systems Advanced Digital System Design is crucial because I am escape in PIC knowledge and it is new to me and it posts a risk to me.12.0 Conclusion and R ecommendationNow just a beginning stage of the project, I have provided a clear view of the objectives and aims of metal detector project and i will complete the entire task stated mistreat by step by following the project planning time. My project planning has stated clearly through the Gantt chart as well as the critical form analysis.The entire research and development job has been done throughout this semester but it still in the early stage the final project. Hence, more information from supervisor, reference book and internet needed. I can increase my knowledge level by workout with the research activity and this may help me to boost up my project to quality completion.In addition, found that many interested features and ideas can be added on to the project. But the insufficient time, knowledge and financial problems have certified me to achieve those extra features. However, if possible I will try my best to achieve it.The extra features areMeasuring of the deeper of the underground metalPassword is required to activate the metal detectorRobot arm added to the mobile metal detectorAs a conclusion, this project smart metal detector may give me experience as an equipment and product engineer with excellent technical and management skills with moral values and bring future benefits to me as an engineer.13.0 References1 http//travel.howstuffworks.com/airport-security.htm1 http//www.losttreasure.com/auction/APViewInCat.asp?ID=72 http//inventors.about.com/library/inventors/blmetal_detector.htm3 http//home.howstuffworks.com/metal-detector1.htm4 http//www.microchip.com