16-01-2013, 02:33 PM
Seminar Report on SMART SENSOR
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Abstract
“Smart” sensors with embedded microprocessors and wireless communication
links have the potential to change fundamentally the way civil infrastructure systems are monitored ,controlled, and maintained. Indeed, a 2002 National Research Council report noted that these of networked systems of embedded computers and sensors throughout society could well previous milestones in the information revolution.
However, a framework does not yet exist that can allow the distributed computing paradigm offered by smart sensors to be employed
for structural health monitoring and control systems; current algorithms assume that all data is centrally collected and processed. Such an approach does not scale to systems with densely instrumented arrays of sensors that will be required for the next generation of structural health monitoring
and control systems. This paper provides a brief introduction to smart sensing technology and identifies some of the opportunities and associated challenges.
Introduction
The SMART concept provides a standard platform for the complete range of sensor products.
The processing power of the system is powerful enough to include complete linearity correction and temperature stability over a wide range.
The design, fabrication, and construction of smart structures is one of the ultimate challenges to engineering researchers today. Because they form the essence of system intelligence, one of the cores of smart structures technology centers around innovative sensors and sensor systems.
The ability to continuously monitor the integrity and control the responses of structures in real time can provide for increased safety to the public, particularly with regard to the aging structures in widespread use today.
The ability to continuously monitor the integrity and control the responses of structures in real time can provide for increased safety to the public, particularly with regard to the aging structures in widespread use today. Consequently, global communication in a wireless fashion that will facilitate low-cost, densely distributed sensing has been investigated.
To assist in dealing with the large amount of data that is generated by a monitoring system, on-board processing at the sensor allows a portion of the computation to be done locally on the sensor’s embedded microprocessor.
Construction of sensors
There have been some active movements toward a decrease in the cost of production equipment and the reduction of the total cost by miniaturizing the equipment and decreasing the floor area.
We developed an amplifier unit as the first smart sensor model that connects to both displacement sensor heads and linear sensors. Then we made a platform for the smart sensor.
We will develop this platform for other sensors, such as magnetic displacement sensors and ultrasonic displacement sensors.
1) Acoustic or sound
Microphone
A Microphone is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal.Microphones are used in many applications such as telephones, tape recorders, karaoke systems, hearing aids, motion picture production, live and recorded audio engineering, FRS radios, megaphones, in radio and television broadcasting and in computers for recording voice, speech recognition and for non-acoustic purposes such as ultrasonic checking or knock sensors.Most microphones today use electromagnetic induction (dynamic microphone), capacitance change (condenser microphone), piezoelectric generation or light modulation to produce an electrical voltage signal from mechanical vibration.
• Condenser microphone
The condenser microphone is also called a capacitor microphone or electrostatic microphone — capacitors were historically called condensers. There are two types, depending on the method of extracting the audio signal from the transducer: DC-biased microphones, and radio frequency (RF) or high frequency (HF) condenser microphones. With a DC-biased microphone, the plates are biased with a fixed charge (Q). The voltage maintained across the capacitor plates changes with the vibrations in the air, according to the capacitance equation (C = Q⁄V), where charge Q = in coulombs, C = capacitance in farads and V = potential difference in volts. The capacitance of the plates is inversely proportional to the distance between them for a parallel-plate capacitor.
Chemical
Pellistor
A Pellistor is a solid-state device which used to detect gases . The detecting element consist of small "pellets" of catalyst loaded ceramic whose resistance changes in the presence of gas. The word "pellistor" is a combination of pellet and resistor.
Pellistor is used to detect gases which are either combustible or which have a significant difference in thermal conductivity to that of air. The thermal conductivity (TC) pellistor works by measuring the change in heat loss detecting element in the presence of the target gas.
Electrical
Galvanometer
A Galvanometer is a type of ammeter and instrument for detecting and measuring electric current . It is an analog electromechanical transducer that produces a rotary deflection of some type of pointer in response to electric current flowing through its coil in a magnetic field.
Sensitive galvanometers were used to detect signals from long submarine cables, and were used to discover the electrical activity of the heart and brain.
Pressure
Pressure sensor
A Pressure sensor measures pressure typically of gases or liquids. Pressure sensors are used for control and monitoring in thousands of everyday applications. Pressure sensors can also be used to indirectly measure other variables such as fluid/gas flow, speed, water level, and altitude. Pressure sensors can alternatively be called pressure transducers, pressure transmitters, pressure senders, pressure indicators and piezometers, manometers.
Some pressure sensors, such as those found in some traffic enforcement cameras, function in a binary (on/off) manner, i.e., when pressure is applied to a pressure sensor, the sensor acts to complete or break an electrical circuit. These types of sensors are also known as a pressure switch. These sensors are commonly manufactured out of piezoelectric materials such as quartz.
Proximity sensor
A Proximity sensor is a sensor able to detect the presence of nearby objects without any physical contact. A proximity sensor often emits an electromagnetic field or a beam of electromagnetic radiation.
The object being sensed is often referred to as the proximity sensor's target. Different proximity sensor targets demand different sensors. For example, a capacitive photoelectric sensor might be suitable for a plastic target; an inductive proximity sensor always requires a metal target.
The maximum distance that this sensor can detect is defined "nominal range". Some sensors have adjustments of the nominal range or means to report a graduated detection distance.
RADAR
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations.
The radar dish or antenna transmits pulses of radio waves or microwaves which bounce off any object in their path. The object returns a tiny part of the wave's energy to a dish or antenna which is usually located at the same site as the transmitter.
Conclusion:
Measurements and Instrumentation system will be developed by using smart sensor in future. Silicon is very suitable material for fabrication of smart sensors.
The smart sensors are very costly , highly accurate and reliably. The smart sensors revolution going to effect the market in the whole world.
In the future, the development of smart materials and structures will pay a major role in all engineering disciplines.
[attachment=47184]
Abstract
“Smart” sensors with embedded microprocessors and wireless communication
links have the potential to change fundamentally the way civil infrastructure systems are monitored ,controlled, and maintained. Indeed, a 2002 National Research Council report noted that these of networked systems of embedded computers and sensors throughout society could well previous milestones in the information revolution.
However, a framework does not yet exist that can allow the distributed computing paradigm offered by smart sensors to be employed
for structural health monitoring and control systems; current algorithms assume that all data is centrally collected and processed. Such an approach does not scale to systems with densely instrumented arrays of sensors that will be required for the next generation of structural health monitoring
and control systems. This paper provides a brief introduction to smart sensing technology and identifies some of the opportunities and associated challenges.
Introduction
The SMART concept provides a standard platform for the complete range of sensor products.
The processing power of the system is powerful enough to include complete linearity correction and temperature stability over a wide range.
The design, fabrication, and construction of smart structures is one of the ultimate challenges to engineering researchers today. Because they form the essence of system intelligence, one of the cores of smart structures technology centers around innovative sensors and sensor systems.
The ability to continuously monitor the integrity and control the responses of structures in real time can provide for increased safety to the public, particularly with regard to the aging structures in widespread use today.
The ability to continuously monitor the integrity and control the responses of structures in real time can provide for increased safety to the public, particularly with regard to the aging structures in widespread use today. Consequently, global communication in a wireless fashion that will facilitate low-cost, densely distributed sensing has been investigated.
To assist in dealing with the large amount of data that is generated by a monitoring system, on-board processing at the sensor allows a portion of the computation to be done locally on the sensor’s embedded microprocessor.
Construction of sensors
There have been some active movements toward a decrease in the cost of production equipment and the reduction of the total cost by miniaturizing the equipment and decreasing the floor area.
We developed an amplifier unit as the first smart sensor model that connects to both displacement sensor heads and linear sensors. Then we made a platform for the smart sensor.
We will develop this platform for other sensors, such as magnetic displacement sensors and ultrasonic displacement sensors.
1) Acoustic or sound
Microphone
A Microphone is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal.Microphones are used in many applications such as telephones, tape recorders, karaoke systems, hearing aids, motion picture production, live and recorded audio engineering, FRS radios, megaphones, in radio and television broadcasting and in computers for recording voice, speech recognition and for non-acoustic purposes such as ultrasonic checking or knock sensors.Most microphones today use electromagnetic induction (dynamic microphone), capacitance change (condenser microphone), piezoelectric generation or light modulation to produce an electrical voltage signal from mechanical vibration.
• Condenser microphone
The condenser microphone is also called a capacitor microphone or electrostatic microphone — capacitors were historically called condensers. There are two types, depending on the method of extracting the audio signal from the transducer: DC-biased microphones, and radio frequency (RF) or high frequency (HF) condenser microphones. With a DC-biased microphone, the plates are biased with a fixed charge (Q). The voltage maintained across the capacitor plates changes with the vibrations in the air, according to the capacitance equation (C = Q⁄V), where charge Q = in coulombs, C = capacitance in farads and V = potential difference in volts. The capacitance of the plates is inversely proportional to the distance between them for a parallel-plate capacitor.
Chemical
Pellistor
A Pellistor is a solid-state device which used to detect gases . The detecting element consist of small "pellets" of catalyst loaded ceramic whose resistance changes in the presence of gas. The word "pellistor" is a combination of pellet and resistor.
Pellistor is used to detect gases which are either combustible or which have a significant difference in thermal conductivity to that of air. The thermal conductivity (TC) pellistor works by measuring the change in heat loss detecting element in the presence of the target gas.
Electrical
Galvanometer
A Galvanometer is a type of ammeter and instrument for detecting and measuring electric current . It is an analog electromechanical transducer that produces a rotary deflection of some type of pointer in response to electric current flowing through its coil in a magnetic field.
Sensitive galvanometers were used to detect signals from long submarine cables, and were used to discover the electrical activity of the heart and brain.
Pressure
Pressure sensor
A Pressure sensor measures pressure typically of gases or liquids. Pressure sensors are used for control and monitoring in thousands of everyday applications. Pressure sensors can also be used to indirectly measure other variables such as fluid/gas flow, speed, water level, and altitude. Pressure sensors can alternatively be called pressure transducers, pressure transmitters, pressure senders, pressure indicators and piezometers, manometers.
Some pressure sensors, such as those found in some traffic enforcement cameras, function in a binary (on/off) manner, i.e., when pressure is applied to a pressure sensor, the sensor acts to complete or break an electrical circuit. These types of sensors are also known as a pressure switch. These sensors are commonly manufactured out of piezoelectric materials such as quartz.
Proximity sensor
A Proximity sensor is a sensor able to detect the presence of nearby objects without any physical contact. A proximity sensor often emits an electromagnetic field or a beam of electromagnetic radiation.
The object being sensed is often referred to as the proximity sensor's target. Different proximity sensor targets demand different sensors. For example, a capacitive photoelectric sensor might be suitable for a plastic target; an inductive proximity sensor always requires a metal target.
The maximum distance that this sensor can detect is defined "nominal range". Some sensors have adjustments of the nominal range or means to report a graduated detection distance.
RADAR
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations.
The radar dish or antenna transmits pulses of radio waves or microwaves which bounce off any object in their path. The object returns a tiny part of the wave's energy to a dish or antenna which is usually located at the same site as the transmitter.
Conclusion:
Measurements and Instrumentation system will be developed by using smart sensor in future. Silicon is very suitable material for fabrication of smart sensors.
The smart sensors are very costly , highly accurate and reliably. The smart sensors revolution going to effect the market in the whole world.
In the future, the development of smart materials and structures will pay a major role in all engineering disciplines.