Week : 3
Title : motion detector
Objective : To know the function of this components.
Contents / Procedures :
Motion sensor is a device for motion detection.Motion detection is a process of confirming a change in position of an object relatives to its surroundings or the change in the surroundings relative to an object.
Title : motion detector
Objective : To know the function of this components.
Contents / Procedures :
Motion sensor is a device for motion detection.Motion detection is a process of confirming a change in position of an object relatives to its surroundings or the change in the surroundings relative to an object.
Passive infrared sensor (passive)
- senses body heat. No energy is emitted from the sensor.
Ultrasonic (active)
- sends out pulses of ultrasonic waves and measures the reflection off a moving object.
Microwave (active)
- sensor sends out microwave pulses and measures the reflection off a moving object. Similar to a police radar gun.
Tomographic detector (active)
- senses disturbances to radio waves as they travel through an area surrounded by mesh network nodes. Has the ability to detect through walls and obstructions.
Result / Analysis :
Passive infrared sensor (PIR sensor) is an electronic sensor that measures infrared (IR) light radiating from objects in its field of view.They are most often used in PIR-based motion detectors.A PIR-based motion detectors is used to sense movement of people, animals, or other objects. They are commonly used in burglar alarms or automatically-activated lighting systems.As an object, such as human, passes in front of the background, such as a wall, the temperature at that point will rise from room temperature to body temperature and then back again.This quick change triggers the detection.Moving object of identical temperature will not trigger a detection.
Ultrasonic sensor (also known as transceivers when they both send and receive) work on a principle similar to radar or sonar which evaluate attributes of a target by interpreting the echoes from radio or sound waves respectively. Ultrasonic sensors generate high frequency sound waves and evaluate the echo which is received back by the sensor. Sensors calculate the time interval between sending the signal and receiving the echo to determine the distance to an object.This technology can be used for measuring: wind speed and direction (anemometer), fullness of a tank and speed through air or water.
Microwave Sensors, also known as Radar or Doppler sensors have been used to activate automatic doors for decades. Today's safety standards such as ANSI/BHMA A156.10 have been the driving force for improvement of microwave technology in automatic door applications.The microwave sensor sends out a high frequency sound wave while listening for bounce back. When the sound wave is returned at a different frequency the sensor knows that there is a moving object within the detection zone. It then sends a signal to the internal relay, which is wired to the door control's activation input.
Tomographic motion detection (TMD) technology is the next generation of motion sensing. Tomographic Motion Detection system can be completely hidden from sight, can see through walls and obstructions, and is virtually impossible to defeat. The system integrates easily with existing panel equipment using normally-closed and normally-open contacts. This devices can be quickly placed in convenient locations without worrying about obstructions or areas that are problematic for infrared and cameras systems. The nodes are simply plugged in or wired around the area of interest, and motion is detected inside the perimeter of the network. The devices can even be embedded within walls for heightened security and aesthetics.
Conclusion :
For my project i will used passive infrared sensor (PIR). Its capability on detecting motion with a simple design at lowest cost is needed to build an effective house security system based on motion detection.
- senses body heat. No energy is emitted from the sensor.
Ultrasonic (active)
- sends out pulses of ultrasonic waves and measures the reflection off a moving object.
Microwave (active)
- sensor sends out microwave pulses and measures the reflection off a moving object. Similar to a police radar gun.
Tomographic detector (active)
- senses disturbances to radio waves as they travel through an area surrounded by mesh network nodes. Has the ability to detect through walls and obstructions.
Result / Analysis :
Passive infrared sensor (PIR sensor) is an electronic sensor that measures infrared (IR) light radiating from objects in its field of view.They are most often used in PIR-based motion detectors.A PIR-based motion detectors is used to sense movement of people, animals, or other objects. They are commonly used in burglar alarms or automatically-activated lighting systems.As an object, such as human, passes in front of the background, such as a wall, the temperature at that point will rise from room temperature to body temperature and then back again.This quick change triggers the detection.Moving object of identical temperature will not trigger a detection.
Ultrasonic sensor (also known as transceivers when they both send and receive) work on a principle similar to radar or sonar which evaluate attributes of a target by interpreting the echoes from radio or sound waves respectively. Ultrasonic sensors generate high frequency sound waves and evaluate the echo which is received back by the sensor. Sensors calculate the time interval between sending the signal and receiving the echo to determine the distance to an object.This technology can be used for measuring: wind speed and direction (anemometer), fullness of a tank and speed through air or water.
Microwave Sensors, also known as Radar or Doppler sensors have been used to activate automatic doors for decades. Today's safety standards such as ANSI/BHMA A156.10 have been the driving force for improvement of microwave technology in automatic door applications.The microwave sensor sends out a high frequency sound wave while listening for bounce back. When the sound wave is returned at a different frequency the sensor knows that there is a moving object within the detection zone. It then sends a signal to the internal relay, which is wired to the door control's activation input.
Tomographic motion detection (TMD) technology is the next generation of motion sensing. Tomographic Motion Detection system can be completely hidden from sight, can see through walls and obstructions, and is virtually impossible to defeat. The system integrates easily with existing panel equipment using normally-closed and normally-open contacts. This devices can be quickly placed in convenient locations without worrying about obstructions or areas that are problematic for infrared and cameras systems. The nodes are simply plugged in or wired around the area of interest, and motion is detected inside the perimeter of the network. The devices can even be embedded within walls for heightened security and aesthetics.
Conclusion :
For my project i will used passive infrared sensor (PIR). Its capability on detecting motion with a simple design at lowest cost is needed to build an effective house security system based on motion detection.
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