The Motion Detector Sensor Engineering Essay

The effect Detector Sensor Engineering EssayHome automation is a dodging that examples to help the occupant to do the household activity or housework. These housework or household activity female genitals be from pet feeding, plant watering, home entertainment system and so on. It spate be manoeuvre each automatic altogethery or sometime assert remotely which all depend to the home resident 2. The immaculate system fuck be controlled by apply from remove control, computer, internet until telephone. The home automation cover very wide of hoe system and it is also including home security system. The home security system basically can be separate to five categories 3, there areDetection of intrusion framework of presenceDetection of fire, gas and waterMedical alert and preciseSafe closing of fraudFor this project, totally 2 categories have been discussed. There are observeion of intrusion and detection of fire. And there are 4 types of intrusion which are 3i) Detection of endeavorii) Magnetic contact of door or windowpaneiii) Glass breaking and pres trustworthy changeiv) Pressure change2.1 Part research and analysis2.1.1 bowel course demodulator sensing elementOnly detection of movement has been discussed for this project. In here, the detection of movement means the movement that spend a penny by human being and a interrogative detector sensing element being use to detect the crusade. A exercise detector detector can separate to active and unresisting and it can detect doing by using optics or acoustics. An active consummation detector sensor is dispersing a constant cranial orbit to detect consummation. The plain allowing remains static until something is enters it then disturbs the reflected pattern. Meanwhile, a wipe outive communicate sensor is waiting in standby mode in order to trigger a scepter drawting when motion is detected. However, active and passive technique both(prenominal) have similar disadvantage. They on ly can sense very limited range that may weaken with distance. As the result, combination of both techniques has been used to gain greater effectiveness to detect the motion 4. There are some(prenominal) types of motion detector sensor being use in the market 5 for examplei) Infrared motion detector sensorInfrared motion sensor is the most reliable and cheapest among the entire motion sensors available in the market. The concept of infrared emission light motion sensor is using the infrared light spectrum to measure the heat of disapproves that pass in front of it. Then it will compare the heating level to heating level that cause by objects that behind it. The wavelength infrared wave is between 0.7 and 300 micrometers barely haplesser than thewavelengthofvisible lightbut interminable than microwave ovens that cannot be detected by human senses but can felt as the heat. This infrared motion detector sensor can be fitted with different lenses to get greater distances.Basicall y the infrared motion detector sensor separate to 2 types only, there are passive and active infrared motion sensor 6. The passive infrared sensors will detect electromagnetic radiated elan vital that fetch by external sources like thermal cipher emitted by people in the infrared range as figure.The thermal energy will reaches to the sensor that comprise more than one individualsensor which make from pyroelectric materials. This sensor will generate an galvanising voltage according it is heated or cooled 7. take in 1 The operation of passive motion infrared sensor 8Meanwhile, the active infrared sensors will generate a multiple smooth pattern of modulated infrared energy and react if it has change in the modulation of the frequency or an interruption in the received energy. The active infrared motion basically consist emitter and telephone receiver pairs to generate IR detection zone. However, this emitter and receiver pairs need to adjust probably to arrive at the best balan cing between reflected IR energy and transmitted IR energy. This balance is called as the threshold level of reflected IR. If the reflected IR energy significantly above the threshold level, IR motion detector sensor will trigger on as figureFigure 2 The operation of active motion infrared sensor 9ii) Microwave motion detector sensorFigure 3 The operation of microwave motion sensor 10The microwave motion detector sensor is type of active sensor that using radar callDoppler radar to send out microwaves in order to detect and measure the movement of an object. Then it will receive the returning waves that cause by moving object to determine the distance, counselling even the look sharp up of the object. Basically the microwave motion detector has 2 types, they called bistatic and monostatic 11.The bistatic type contains emitter and receiver which keep in line separately to configure the beam to fit particular situation. It has a with infant(p)r detection range which up to 1500 l inear feet but it cannot define the force field of detection and easy to cause the error 12. Meanwhile, the monostatic type can define detection area based on microwave beam that it emits. The detection range is small than bistatic which only 400 linear feet but it more efficient 12.Although the microwave motion detector sensor cover a larger area than infrared sensor and more reliable over longer distances, but it is least popular because of their vulnerability to electrical interference and expensive cost 11.iii) extremistsonic motion detector sensorFigure 4 The operation of ultrasonic motion sensor 13An ultrasonicmotion detector sensor will detect the movement by generating the sanitary wave in the ultrasonic frequency range more or less 30 kHz to 50 kHz within the limited area 14. It will generate a cone-shaped cloggy wave and listen to the echoes. . The phone wave chiefly inaudible to humans and most animals but it does not pass through most objects. So, if no object i s moving within the zone of detection, the pattern of sound wave in its environment and the time that reflected back down will remain the kindred. However, if something moves, the microwave detector will detect and analysis the level or stagecoach of returning sound waves then will trigger on the sensor 14. Basically this ultrasonic motion detector sensor separated to 2 types, there are active and passive. 15The active ultrasound motion detector sensors emit sound waves from quartz-crystal transducers then the sound wave will cover within the field of detection. The sound wave will not disrupt if there is no any movement detected. However, the sound wave will disrupt when movement detected and reflected back to receiver. The receiver will sent the foretell to control unit and trigger on the sensor by analysis its sensitivity and calibration. Although the microwave motion detector sensor very efficiency in performance, but it is weak in very short of the field of detection that o nly detectable up to forty feet 15.Meanwhile the passive motion detector sensors operate on the principle of sounds for example breaking glass to trigger on the sensor. These sounds produce sound waves that detected by the sensors which homogeneous concept like the active sensors. The signal will sent to control units to determine if the sound wave pattern falls within established normal parameters 15. parry down the stairs is the summary of technologies to detect the motionTechniqueDescriptionAdvantagesDisadvantages1) Infrared6Active Generate multiple beam of modulated infrared energy and receive any interrupt or change of received energyPassive detect electromagnetic radiated energy that generate by external sources like thermal energyi) Low costii) Easy to maintaini) finish off very small area2) Microwave12Cover area with electronic field and receive any disturb or movement of electronic fieldi) Cover large areaii) Quick responsei)High costii)Too sensitive3) Ultrasonic15Genera te sound wave and reflect the sound wave if any disturb or movementi) Cover large areaii) Quick responseiii) Long lifetimei) Easy affect by environment shakingii) High costTable 1 Summary and comparison of 3 technologies to detect the motion2.1.2 alter detector sensorFor another category which is detection of fire, there also have several techniques to detect it. These techniques are sensing in temperature, humidity and smoke 3 and sensing in temperature will be discussed in this project. There are few technologies in this market to sense the temperature 16 like tableTechnologiesDescriptionAdvantagesDisadvantages1)Thermocouple17 constitute junction of 2 types of metal that joined together will produce voltage which varies with temperature changei) can used in wide temperatureii)Fast responsei) Low accuracyii) short life time2) resistance thermometer (RTD) 18Electrical resistance of pure metal will increase with rise of temperaturei) High accuracyii) wide stabilityi)Slow response ii) High cost3) Thermistor19Type of ceramic resistor that resistance will change with temperature changingi) Accuracy in small scale of temperature rangeii) Good vibrationi) pose in small temperature rangeTable 2 Summary and comparison 3 of technologies to sense the temperature in the market2.1.3 Wireless system applicationShort range radio applicationThe table to a lower place show that the summary of some short range radio application and characteristics that use in the market.applications programme oftennessCharacteristicsSecurity system300MHz -500MHz,800MHz,900MHZSimplicity, easy installationEmergency medical al subdivisions300MHz-500MHz,800MHzConvenient carrying, long bombing life, reliableComputer accessoriesUHF(Ultra High frequency)High info rates, vary short range, low costRFID (Radio Frequency Identification)100kHz to 2.4GHzVary short range, active or passive transponderWireless microphone and headphoneVHF(Very High Frequency), UHF( Ultra High frequency)Analog steep fi delity voice modulation, moderate priceKeyless entry(gate opener)UHF(Ultra High Frequency) toy dog transmitter, special coding to prevent duplicationWireless bar code readers900MHz, 2.4GHzIndustrial use, spread spectrumTable 3 Short range radio application 20Figure 5 Radio communication liaison diagram 21Figure above is the radio communication link diagram. In transmitter, the source data will send to encoder to create a group of bits then sent the signal to receiver to make sure that no any turned occurrences happen. Then the receiver will check and only accept the signals that the same address bits same with it. The signal that sent which also call message frame has 4 field 21 like figureFigure 6 Message frame 21The first field is called preamble that as start bits to tell the receiver the message begins. Next field is called address, it will identify address and notifies the receiver come from which units that message is coming which sent by transmitter. Then the data field wil l find out on which it may indicate what type of event is being signaled in some protocols. Finally rifle field is parity which allows the receiver to determine whether the message was received correctly or not 21.When several transmitters are used with the same receiver, all transmitters need to have the same identification address which set by receiver where receiver need to be set to recognize the identification address of all the transmitters that used in the system. Table below is the summary of advantage and disadvantages of two addressing system 21AdvantagesDisadvantagesUnlimited list of transmitter can be used with a receiverLimited telephone number of bits increase simulated number and interference from adjacent systemCan be used with commercially available data encoder and decodersDevice must be opened for coding during installationTransmitter and receiver can be easily replaced without recoding the opposite terminalMust be used with a dedicated microcontroller and ca nnot be used with standard encoders and decodersEach transmitter is individually recognized by receiverLimited number of transmitters can be used with each receiverLarge number of code bits reduces possibility of false numberLonger code reduces probability of detectionTable 4 Advantages and disadvantages of two addressing system 212.2 retrospect of similar productNoProductSpecificationCostReference1Motion detector alarm set Detect motion and activates alarm-Build in high output 105dB alarm-Keypad to arm or disarm and security code-120VAC adapter operateUS$24.99222Wireless motion system CWA2000 Transmitter can transmit signal to receiver until half mile away-Activates take and buzzer on base station when detect motion-Expendable up to 8 motion sensor-Can adjust sensitivity of detection-Receiver needed AC power and 4 AA batteries for support mode-Sensor required 4 AA batteriesUS$99.00233Skylink SC-10 wireless Home security system-Consists 2 door or window sensors and 2 keychain tr ansmitter-Arm or Disarm by using keychain transmitter-Build in high output 110dB witch-Expendable up to 15 sensors operate by AC power and 4 AA batteries for backup modeUS$109.95244Powermax + wireless intruder alarm-Support real time viewing from camera-Consist 3 PIR sensor and 2 magnetic door sensor with wireless-External high output siren-Sent message to user by email, SMS or phone when any incident happened-Support latchkey to inform parent when child arrive to home-Remote home management which provide control and status update up to electrical devices-Required AC power to operate257.00253.7 Hardware description3.7.1 pic16F874A microcontrollerFigure 14 Pin description of PIC16F874A microcontroller 26The demeanor of the Home Security system basically control by three PIC 16F8XX microcontrollers. The PIC16F8XX microcontroller is under check PIC microcontroller device and very commonly being use because of low-cost, low-power use but high speed in performance and I/O flexibilit y if compare to other device and family. The microcontroller emphasizes almost same function as a microprocessor but PIC Microcontroller only operates at very low speed or frequency which only few MHz or even lower if compare to microprocessors that operate with high speed or frequency. Besides, PIC microcontroller consumes very small among of power consumption which only around miliwatts. So, PIC Microcontroller is more suitable for home security system compared to microprocessor in terms of size, cost, power consumption and the memory to control the input/output devices.They are three types of microcontroller also take into consideration, which are PIC 16F84A 27, PIC16F874A 26 and Atmel-AT89C2051 28.The comparison was made before the final decision make. Below is the table of comparison between 3 microprocessorsFeaturesMicrochip (PIC16F84A)Microchip(PIC16F874A)Atmel(ATmega88V)Instruction35 single countersignature35 single word131 single wordOperating speed20MHz20MHz20MHzFlash Pro gram Memory1024 x 14 words4k x 14 words8k x 14wordsData Memory(RAM)68 x 8 bytes192 x 8 bytes1k bytes internal SRAMEEPROM64 x 8 bytes128 x 8 bytes512 x 8 bytesI/O port wine133323Counter/timer132Counter bit8 bits16 bits16 bitsSeries Interface (MSSP)-In-Circuit Serial Programming (ICSP) viatwo pins Synchronous Serial Port (SSP) with SPI(Master mode) IC (Master/Slave) Master/Slave SPI Serial Interface Byte-oriented 2-wire Serial Interface (Philips IC compatible)Operating Voltage2.0V-5.5V2.0V 5.5V1.8V 5.5VSoftware MPLAB IDE MPLAB ICD2 MPLAB IDE MPLAB ICD2ATAVRISP