ARM Based Gas Leakage Detection System Projects For Final Year Engineering Students                        

Introduction:

Gas leak detection is the process of identifying potentially hazardous gas leaks using various sensors. These sensors usually employ an audible alarm to alert people when a dangerous gas has been detected. Common sensors used today include infrared point sensors, ultrasonic sensors, electrochemical gas sensors, and semiconductor sensors. More recently, infrared imaging sensors have come into use. All of these sensors are used for a wide range of applications and can be found in industrial plants, refineries, wastewater treatment, etc.

Block Diagram Explanation:

Power supply unit

This section needs two voltages viz., +12 V & +5 V, as working voltages. Hence specially designed power supply is constructed to get regulated power supplies.

Zigbee technology:

 ZigBee is the name of a specification for a suite of high-level communication protocols using small, low-power digital radios based on the IEEE 802.15.4 standard for wireless personal area networks (WPANs).

• A very low-cost, low power consumption two-way, wireless communication standard for automation, toys & PC peripherals.
• Low power consumption: 6 months to 5 years battery life for most applications.
• Low cost: At least half the cost of Bluetooth solutions.
• The high density of nodes per network: 250 nodes per network, multiple co-located networks.Data rate requirements: Few bits to 250kbps sufficient.

ARM processor:

  ARM is a computer processor-based RISC architecture. A RISC-based computer design approach means ARM processors require significantly fewer transistors than typical processors in average computers. This approach reduces costs, heat, and power use. The low power consumption of ARM processors has made them very popular:

The ARM architecture (32-bit) is the most widely used in mobile devices, and the most popular 32-bit one in embedded systems.

ARM processor features include:

1. Load/store architecture.
2. An orthogonal instruction set.
3. Mostly single-cycle execution.
4.  16×32-bit register
5. Enhanced power-saving design.

MQ–SENSOR

MQ-6 gas sensor is composed of a micro AL2O3 ceramic tube, Tin Dioxide (SnO2)  sensitive layer, measuring electrode, and heater are fixed into a crust made of plastic and stainless steel net. The heater provides necessary work conditions for the work of sensitive components. The enveloped MQ-6 has 6 pins, 4 of them are used to fetch signals, and the other 2 are used for providing heating current.

Buffers

Buffers do not affect the logical state of a digital signal (i.e. a logic 1 input results in a logic 1 output whereas logic 0 input results in a logic 0 output). Buffers are normally used to provide extra current drive at the output but can also be used to regularize the logic present at an interface

Drivers

This section is used to drive the relay where the output is the complement of input which is applied to the drive but the current will be amplified.

Relays

It is an electromagnetic device that is used to drive the load connected across the relay and the o/p of the relay can be connected to the controller or load for further processing.

Buzzer:

A buzzer or beeper is an audio signaling device, which may be mechanical, electromechanical, or piezoelectric. Typical uses of buzzers and beepers include alarm devices, timers, and confirmation of user input such as a mouse click or keystroke.

Methodology:

The transmitter will have a Gas sensor, when the gas is detected it gives the signal to the ARM, then the ARM will send the information to another receiving station through ZIGBEE which is in a Police station or security office. At the same time, ARM will generate the output that is fed to buffer IC 4050, buffer stores and given to the driver IC 2003  in driver current will amplify and voltage will invert with the help of the Darlington circuit of driver IC  to drive the relay. Then the signal is  given to the output load for indication purpose

Advantages:

1. Used in-house as an LPG gas detector
2. It also detects alcohol so it is used as a liquor tester.
3. The sensor has excellent sensitivity combined with a quick response time  

Disadvantages:

1. It is a little sensitive to smoke then it is not perfectly reponse for LPG gas detection.

2. Its sensitivity depends on Humidity and temperature.

Applications:

1. Fire/Safety detection system
2. Gas leak alarm
3. Gas detector