The Motion Detector Sensor Engineering Essay

The Motion Detector Sensor Engineering EssayHome automation is a agreement that uses to help the resident to do the household activity or housework. These housework or household activity can be from dearie feeding, plant watering, home entertainment system and so on. It can be run away either automatic eithery or sometime program line remotely which all depend to the home resident 2. The entire system can be controlled by using from remove control, computer, internet until telephone. The home automation covered real wide of hoe system and it is also including home security system. The home security system basically can be separate to five categories 3, on that point areDetection of intrusionSimulation of presenceDetection of fire, gas and waterMedical alert and preciseSafe closing of blindFor this project, wholly 2 categories have been discussed. There are pick upion of intrusion and detection of fire. And in that respect are 4 types of intrusion which are 3i) Detection of movementii) charismatic contact of door or windowiii) Glass breaking and pressure changeiv) Pressure change2.1 Part research and analysis2.1.1 Motion sensing element sensorOnly detection of movement has been discussed for this project. In here, the detection of movement means the movement that cause by human being and a apparent movement demodulator sensor being use to detect the bowel movement. A effort comprehend element sensor can separate to mobile and manoeuvreive and it can detect motion by using optics or acoustics. An active motion sensor sensor is dispersing a constant athletic field to detect motion. The field leave behind trunk static until something is enters it then unsettles the reflected pattern. Meanwhile, a passive motion sensor is waiting in standby rule in order to trigger a sceptre setting when motion is detected. However, active and passive technique both have standardised dis favor. They precisely can sense very limited range that whitethor n weaken with distance. As the result, combination of both techniques has been employ to gain greater effectiveness to detect the motion 4. There are several types of motion demodulator sensor being use in the grocery 5 for examplei) Infrared motion detector sensorInfrared motion sensor is the most tried and true and cheapest among the entire motion sensors available in the market. The concept of unseeable motion sensor is using the infrared light spectrum to measure the heat of objects that pass in front of it. Then it impart study the heating level to heating level that cause by objects that behind it. The quakelength infrared wave is between 0.7 and three hundred micrometers alone shorter than thewavelengthofvisible lightbut longer than microwaves 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.Basically the infrared motion detector sensor separate to 2 ty pes only, in that location are passive and active infrared motion sensor 6. The passive infrared sensors get out detect electromagnetic radiated energy that generate by outdoor(a) sources alike(p) thermal energy emitted by people in the infrared range as figure.The thermal energy provide reaches to the sensor that comprise to a greater extent than one individualsensor which made from pyroelectric materials. This sensor will generate an electrical voltage according it is heated or cooled 7. record 1 The operation of passive motion infrared sensor 8Meanwhile, the active infrared sensors will generate a multiple beam pattern of modulated infrared energy and react if it has change in the modulation of the frequency or an giveion in the real energy. The active infrared motion basically rest emitter and receiver pairs to generate IR detection zone. However, this emitter and receiver pairs need to adjust probably to achieve the best balancing between reflected IR energy and patrim onial 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 figure figure of speech 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 direct 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, direction even the speed 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 operate singly to configure the beam to fit particular situation. It has a larger detection range which up to 1500 linear feet but it cannot define the area of detection and el ementary to cause the error 12. Meanwhile, the monostatic type can define detection area based on microwave beam that it emits. The detection range is scummyer 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 honest over longer distances, but it is least popular because of their vulnerability to electrical interference and expensive cost 11.iii) Ultrasonic motion detector sensorFigure 4 The operation of ultrasonic motion sensor 13An ultrasonicmotion detector sensor will detect the movement by generating the sound wave in the ultrasonic frequency range around 30 kHz to 50 kHz within the limited area 14. It will generate a cone-shaped sound wave and listen to the echoes. . The sound wave generally inaudible to humans and most animals but it does not pass through most objects. So, if no object is moving within the zone of detection, the pattern of sound wave in its environ ment and the time that reflected back will remain the same. However, if something moves, the microwave detector will detect and analysis the level or phase 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 signal 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 only detectable up to forty feet 15.Meanwhile the passive motion detector sensors operate on the pr inciple of sounds for example breaking glass to trigger on the sensor. These sounds produce sound waves that detected by the sensors which same 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.Table below is the abridgment 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) depressed costii) patrician to maintaini) Cover 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) Ultrasonic15Generate sound wave and reflect the sound wave if any disturb or movementi) Cover large areaii) Quick responseiii ) Long lifetimei) Easy affect by environment vibrationii) High costTable 1 Summary and comparison of 3 technologies to detect the motion2.1.2 Heat 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)Thermocouple17Consist join 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) Good perceptual constancyi)Slow responseii) High cost3) Thermistor19Type of ceramic resistor that resistance will change with temperature changi ngi) Accuracy in small weighing machine of temperature rangeii) Good vibrationi) Limit 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 below show that the summary of some short range radio application and characteristics that use in the market.ApplicationFrequencyCharacteristicsSecurity system300MHz -500MHz,800MHz,900MHZSimplicity, easy facilityEmergency medical alarms300MHz-500MHz,800MHzConvenient carrying, long battery life, reliableComputer accessoriesUHF(Ultra High frequency)High data 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 high fidelity voice modulation, moderate priceKeyless entry(gate opener)UHF(Ultra High Frequency)Miniature transmitter, particular(preno minal) coding to prevent duplicationWireless bar code readers900MHz, 2.4GHzIndustrial use, spread spectrumTable 3 Short range radio application 20Figure 5 Radio communication link 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 false 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 fields 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 will follow on which it may indicate what type of event is being signaled in some protocols. Finally last 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 sum up of transmitter can be used with a receiverLimited number of bits increase false 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 cannot be used with standard encoders and decodersEach transmitter is individually recognized by receiverLimited number of transmitters can be used with each receiver large(p) number of code bits reduces possibility of false numberLonger code reduces probability of detectionTable 4 Advantages and disadvantages of two addressing system 212.2 Review 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 LED and buzzer on base station when detect motion-Expendable up to 8 motion sensor-Can adjust sensitivity of detection-Receiver required AC power and 4 AA batteries for backup mode-Sensor required 4 AA batteriesUS$99.00233Skylink SC-10 wireless Home security system-Consists 2 door or window sensors and 2 keychain transmitter-Arm or Disarm by using keychain transmitter-Build in high output 110dB siren-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 catch 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 cinema16F874A microcontrollerFigure 14 Pin description of PIC16F874A microcontroller 26The behavior of the Home Security system basically control by three PIC 16F8XX microcontrollers. The PIC16F8XX microcontroller is under Microchip PIC microcontroller device and very commonly being use because of low-cost, low-power consumption but high speed in performance and I/O flexibility if compare to other device and family. The microcontroller emphasizes almost same function as a microprocessor but PIC Microcontr oller 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 retention 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. downstairs is the table of comparison between 3 microprocessorsFeaturesMicrochip (PIC16F84A)Microchip(PIC16F874A)Atmel(ATmega88V)Instruction35 single word35 single word131 single word run speed20MHz20MHz20MHzFlash Program 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 Port133323Counter/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) operational Voltage2.0V-5.5V2.0V 5.5V1.8V 5.5VSoftware MPLAB IDE MPLAB ICD2 MPLAB IDE MPLAB ICD2ATAVRISP