APLIKASI SENSOR

PYROELECTRICOnki Nur Indrianto

Onkinur.indriant@gmail.comD3 Elektronika Universitas Jember

PYROELECTRIC

A pyroelectric sensor is very sensitive to rapid temperature changes. A rapid change in air temperature due to a breeze from an open window or from an air conditioner or heater can cause false triggering. The shadow and pinhole lenses described above do not offer protection against such air movement because they are actually open lenses. For outdoor use you would also need protection against rain.

PYROELECTRIC

WHAT IS PYRO ELECTRIC?

WHAT IS PYRO ELECTRIC?

PIR sensor memiliki kemampuan untuk mendeteksi gerakan manusia yang masuk dalam range dari sensor. Bentuknya mungil, murah, low-power, dan mudah penggunaannya. Untuk alasan inilah, maka biasanya sensor ini banyak dijumpai pada gadget untuk keperluan rumah tangga dan bisnis. Sensor ini lebih dikenal sebagai PIR, "Passive Infrared", "Pyroelectric", atau sensor "IR motion”.

FOCUSING DEVICES FOR PYROELECTRIC

A pyroelectric sensor has an infrared filter window that admits IR within the 5 to 15 micrometer wavelength range. One end of the two series-connected elements in an analog sensor is connected to pin 3 that is normally grounded. The other end connects internally to the gate of a Field Effect Transistor and to a very high value pulldown resistor. Power is applied to FET drain pin 1 and the output signal comes from FET source pin 2 which usually connects through an external pulldown resistor to ground and to an amplifier. A digital sensor not shown here, includes internal processing circuits and outputs digital pulses.

PACKAGE TIPE TO5

The sensor is housed in a TO5 type package. Sensing elements are each 0.039 inch (1mm) wide and are spaced 0.039 inch (1mm) apart.

DETECTING AREA OF PYROELECTRIC An IR emitting body

moving across the front of a sensor will expose first one, then both and then the other sensor element.

The output signal waveform from an analog sensor shows that for motion in one direction, first a positive, then zero and then a negative transition results. Motion in the other direction will produce first a negative, then zero and then a positive transition.

THE FRESNEL LENS

A Fresnel lens is usually thin and flexible and is about 0.015 inch (0.38mm) thick with grooves molded into one surface. The groove side of the lens usually faces the PIR sensor.

A Fresnel lens both captures more IR radiation and focuses it to a small point. This focal point moves across the sensor as the IR source moves and exposes one element at a time. A Fresnel lens can extend detection range to about 100 feet.

THE FRESNEL LENS

PYROSENSOR WITHOUT LENS

This diagram shows IR exposing both elements equally when no lens is used.

SHADOW LENS

By placing a baffle or mask in front of the sensor, we can block some of the IR and produce a shadow on the sensor

As the IR source moves, the baffle blocks it from exposing one of the sensor elements while fully exposing the other.

SHADOW LENS

This multiple baffle shadow lens provides a wide detection angle. The lens should be curved so all baffles are the same distance from the front of the sensor.

SHADOW LENS

DATASHEET OF PYROELECTRIC PIR325

TYPICAL CONFIGURATION OF PIR (1)

Typically, the FET source terminal pin 2 connects through a pulldown resistor of about 100 K to ground and feeds into a two stage amplifier having signal conditioning circuits.

TYPICAL CONFIGURATION OF PIR (2)

The amplifier is typically bandwidth limited to below 10Hz to reject high frequency noise and is followed by a window comparator that responds to both the positive and negative transitions of the sensor output signal. A well filtered power source of from 3 to 15 volts should be connected to the FET drain terminal pin 1.

EXAMPLE CIRCUIT OF PYROSENSOR (1)

EXAMPLE CIRCUIT OF PYROSENSOR (2)

DIAGRAM ALIR SYSTEM

THE ARTICLE OF PYROELECTRIC SENSORS

MULTIPLE HUMAN TRACKING AND

IDENTIFICATION WITH WIRELESS

DISTRIBUTED PYROELECTRIC SENSORS

ABSTRACT (1)

The advantage of thermal human tracking over the optical counterpart lies in its theoretical and practical illumination invariance. The goal of our research is todevelop a prototype wireless distributed pyroelectric sensor system, which can track multiple human objects inside a room, while maintaining their identities under allillumination circumstances. It involves two sub-problems: multiple thermal source tracking and thermal object identification.

ABSTRACT (2)

Throughout construction of the prototype sensor system, the following topics have been addressed, investigated, and managed:(1)Signal processing balance between photonics

and elec-tronics. (2)Algorithm trade-off between performance and

cost, for real-time system implementation.(3)Distributed computation and communication

mana-gement amongst host, master, and slave modules.

THE GENERAL DIAGRAM OF THERMAL MOTION TRACKING

Pelacakan dan pengenalan adanya gerakan manusia memiliki beberapa bagian yang bekerja secara terpadu yang diiringi dengan beberapa permasalahan terkait. Adapun bagian-bagian tersebut adalah: detection, localization, dan tracking.

MAIN GOALS

1. Walker Detection: Is there someone moving?

2. Walker Tracking: What are their locations?

3. Walker Recognition: Who are the walkers?

THE CHALLENGES

High variability and volatility of human motions and their thermal biometrics

Difficulties in capturing and representing main components of motions/thermal features

Reduced sensitivity of pyroelectric sensors with respect to distant objects.

THE SETUP OF WIRELESS PYROELECTRIC

KONFIGURASI MODUL SENSOR

1. RADIAL SENSOR MODULE

2. TWO COULUMN RADIAL

SENSOR MODULE 3. FOUR SENSOR MODULES

RADIAL SENSOR MODULE

VISIBILITY CODING

TWO COULUMN RADIAL SENSOR MODULE

VISIBILITY CODING

LOCAL DETECTION REGIONS

Visibilities of four sensor modules and four local detection regions

DIGITAL FEATURE EXTRACTION

TERIMA KASIH