Design and Implementation of RF-based Life Saving System for Identifying Human Objects under Earthquake Rubble

Project Title

Design and Implementation of RF-based Life Saving System for Identifying Human Objects under Earthquake Rubble

Project Area of Specialization Electrical/Electronic EngineeringProject Summary

Earthquakes are one of the fatal natural disasters which are invincible and cannot be predicted beforehand. According to the DAWN News Report (January 31st, 2018), we have lost more than 81,000 precious lives (with more than 0.2 million got injuries) in Pakistan in the last couple of decades. The biggest challenge in such situations is the timely recovery of survivors from the earthquake rubble.

Traditional rescue operations (to identify the survivors) generally involve the deployment of trained dogs or manual searches through army persons or local residents. However, these conventional methods not only lack accuracy, but they are also tedious and time-consuming, hence making them severely ineffective in these situations where seconds define life or death. Moreover, such methods are not useful when the area under observation is vast, like the whole villages or the city, etc. Keeping above in view, there’s a dire need to develop an efficient, portable and self-powered system that can scan the large area in a short time and can identify the live buried objects accurately and effectively.

In our project, we propose a portable RF-based live-saving-system which can perfectly address the aforementioned limitations of the conventional methods. The proposed on-chip self-powered system, coupled with the smart and efficient algorithms, ensure not only the compactness but also reliability in terms of accuracy, hence making it an ideal solution for the identification of buried live objects in the case of earthquakes. Moreover, the proposed system can efficiently scan the large area acutely in a short time, and its careful engineering can enable its working or for the larger depths of different kinds of rubbles.

The principle behind the life detection system for buried survivors is the Doppler Effect. When an electromagnetic wave of L or S-band is aimed at a pile of collapsed buildings or earthquake rubble which is consisted of the buried human subject, this EM wave can penetrate through the rubble to reach the object. When the human object is illuminated by the EM wave, then the echo (reflected wave) will be modulated with the human object movement, which includes heartbeat and breathing. If the background clutters can be cancelled from echo signal, mean by proper demodulation, the breathing and heartbeat signal can be extracted by which buried survivor can be detected.

Project Objectives

1. Development of portable, reliable and compact on-chip system for the real-time identification of buried survivors under the earthquake rubble.
2. Development of smart algorithms for the implemented hardware to ensure the efficiency and accuracy of the overall system.
3. Develop an easy-to-use efficient system for the rescuing personals (without having the relevant technical knowledge).
4. Developing a system which can scan a large area in a short time on self-power.
5. Developing a system which can work for the larger depths (like few meters) of different kinds of debris (like soil, concrete).
6. Developing a cost-efficient and less-hectic device

Project Implementation Method

The implementation of this projects can be divided into following phases:

1. Design and development of RF front-ends for the transmitter and receiver.
2. Designing of high gain and long-range antennas for RF transmitter and receiver.
3. Integration of front-ends with FPGA boards and testing/debugging of the developed hardware.
4. Digital processing of the base-band signals and the development of efficient algorithms for real-time processing of the signals received from the buried objects.
5. Bringing the complete hardware on a single chip to make it a portable compact system.
6. Testing the developed on-chip system in a real time outdoor environment to evaluate and analyse its performance.

The general block diagram of the RF System is given below:

Fig.1 general block diagram

First phase of project is consisted of RF front end design which is further categorized into transmitter and receiver block. We are making a portable IC based stand-alone system for which the first step is the selection of IC’s and verification of their power levels through link budget.

The transmitter block consisted of the following components:

1. Voltage Control Oscillator (VCO)
2. Power Splitter
3. High Gain Amplifier (HGA)

The receiver block consist of the following components:

1. Low Noise Amplifier
2. Mixer
3. Attenuator
4. Filter

After selecting all these IC’s based components of transmitter and receiver side is to made the layouts of these individual IC’s and then their fabrication.

The second phase of the project is consist of Antenna designing. The antenna which we are using due to its high gain and directivity is Vivaldi Antenna.

The most important phase of our implementation is getting Doppler shift by signal processing of the received signal from the buried survivor and extracting the useful information from the noise and the reflection of rubble by taking its Fast Fourier Transform (FFT).

The final phase consists of individual IC’s testing and then shifted them to a single PCB sheet for make a stand-alone system. Then this system can be easily portable due to its small size and can be used for real time scenarios for rescuing the buried survivor who become the victim of earthquake.

Fig.2 Overall system block diagram

Benefits of the Project

The benefits of the device are as follows:

1. This non-invasive device is easily portable due to its small size.
2. There will be very less noise figure of this RF system due to the fact it is a miniaturized and stand-alone chip which will help in reliable results.
3. Run time signal processing capability of the received signal.
4. Such a smart RF system can be easily portable in any area especially in northern areas where there is difficulty for rescue team to reach in stony areas.
5. Cost efficient distinction of this device also ensures its access not only to rescue teams but also to ordinary people so they can save the precious lives of their beloved ones in this natural disaster.
6. Availability of hardware-designs and smart algorithms which can be replicated in case of other relevant rescue operations like collapsed building.

Technical Details of Final Deliverable

The technical details of the project for making front-end given below:

Manufacturer	Components	Output power level
Mini circuits	Voltage control oscillator	6 dBm
Mini circuits	High gain amplifier	14 dB
Mini circuits	Low noise amplifier	19 dB
Mini circuits	Power splitter	3 dB
Mini circuits	Attenuator	3 dB
Mini circuits	Mixer	13 dB

In the process of making layouts, we have to DC biased the amplifiers as well, so according to the values of dc biasing SMD components we select their models and then send them for fabrication. Their detail is given below:

SMD Components:

Type of component	Package	value
Capacitor	1206	10nF
Capacitor	0805	1000pF
Inductor	1206	6.8uH

Rogers Sheet (Substrate):

We are using a good substrate for better results which is Rogers RO4350B.

Substrate	Loss tangent	Relative permittivity
RO 4350B	0.0037	3.48

               Manufacturer

Mini circuits

Mini circuits

Mini circuits

Mini circuits

Mini circuits

Mini circuits

Type of component

  Capacitor

  Capacitor

   Inductor

        Substrate

    RO 4350B

Final Deliverable of the Project HW/SW integrated systemCore Industry TelecommunicationOther IndustriesCore Technology OthersOther TechnologiesSustainable Development Goals Good Health and Well-Being for PeopleRequired Resources

Type of component	Package	value
Capacitor	1206	10nF
Capacitor	0805	1000pF
Inductor	1206	6.8uH