LITERATURE REVIEW

INTRODUCTION:

Electricity is a very important thing of our daily life. Without electricity it will be ruined our activities not just for ourselves but also for industrial. But lately, our populations also increase and the decaying of the natural resources energy crisis is becoming a very serious issue all over the world. As example on this crisis based on the whole world is we are dependent upon the fossil fuels for electricity. With a sort time maybe we can use this, but if it still using a fossil for electricity on a long time  it will be eliminated and soon they will be no longer available which is again very serious issue for our upcoming generation.    

JOURNAL 1:

There are a number of approaches being used to generate alternative power supply. One of the method is piezoelectric smart road sensor[1]. On application of mechanical stress on piezo materials equivalent amount of electric current or voltage is produced. This effect can be used in harvesting energy from the smart roads. Priyanshu et.al. says that when any vehicle moves on the roads it produces very small vertical deformations and vibrations on the roads. The increasing demand of the electricity forces us to think about harvesting that vibration energy from vehicles which is wasted otherwise. Also the traffic on the roads has increased to a certain level that if we employ such sensors on the roads it will be a great support in reducing the burden of the fossil fuels.

Energy can be harvested from various energy sources like radiations, light, temperature, vibrations etc. Vibrations are created from different sources like from machines in industrial, moving vehicles on streets and so on. Vibration to electrical energy is changed over by utilizing three distinct ideas i.e. Electromagnetic, Electrostatic and Piezoelectric[2]. The piezo impact created is because of the adjustment in the electric polarization of the materials due to the apply stress which prompts the production of electric current or voltage. The piezoelectric effect was proposed by the curie brothers according to which electric charge is produced, when force is applied parallel to polar axis using crystals of tourmaline, quartz, topaz, cane sugar and Rochelle salt[3]. Piezoelectric crystal are normally happening stable crystal until any outside forces are connected to them. Piezoelectric effect is a  reversible process. It can happen in two ways i.e. coordinate piezoelectric effect and speak piezoelectric effect.

JOURNAL2:

Another journal is [4] Some vibration based energy generators that converts mechanical energy to electrical energy that have been successfully developed are Electromagnetic[5], Electrostatic[6], Piezoelectric generators[7],[8]. There are two effects in piezoelectricity: direct piezoelectric effect and converse piezoelectric effect. Direct piezoelectric effect is the generation of electric charge when mechanical strain is applied on piezoelectric materials; whereas the converse effect is defined as the deformation in the crystal caused, when an electrical voltage is applied to the piezoelectric materials. Direct piezoelectric effect is employed in manufacturing sensors and converse piezoelectric effect is employed in manufacturing actuators. The piezoelectric materials are of natural and also of artificially made. Quartz is a natural piezoelectric material while Lead Zirconate Titanate (PZT) is an artificial piezoelectric material. PZT piezoelectric sensor can be used for small scale energy harvesting because of its high energy storage density[9].

         JOURNAL 3:

Other than that, for research journal is [10].The requirement for a wireless electrical power supply has impelled  an enthusiasm for piezoelectric energy collecting, or the extraction of electrical energy utilizing a vibrating piezoelectric device. Examples of applications that would benefit from such a supply are a capacitively tuned vibration absorber [11],a foot-powered radio “tag” [12], [13], and a PicoRadio [14]. Vibrating piezoelectric device varies from an average electrical power source in that its inner impedance is capacitive rather than inductive in nature, and that it might be driven by mechanical vibrations of changing amplitude and frequency.

On this journal described herein was to develop an approach that maximizes the power transferred from a vibrating piezoelectric transducer to an electrochemical battery. Other than that it is straightforward model of a piezoelectric transducer. An ac–dc rectifier is included what is more, the model is utilized to decide the purpose of ideal power stream for the piezoelectric element. To decide its power flowcharacteristics, a vibrating piezoelectric component is displayed as a sinusoidal current source i_p(t)  in parallel with its inward electrode capacitance C_p.

JOURNAL REFERENCES FOR PROPOSAL

1-) PIEZOELECTRIC SMART ROAD SENSOR

Link: PIEZOELECTRIC SMART ROAD SENSOR

Abstract from Journal:Energy harvesting is an emerging technology in order to meet the demands of the increasing population. Energy can be harvested from various sources like thermal, vibration, chemical etc. Similarly energy can be harvested from the roads by using the piezoelectric effect. This paper summarizes about the sensor that will be a great benefit to the lifetime of the fossil fuels and helps in preventing the environment from polluting due to wastes. This paper presents about the piezoelectric sensor that can be implanted beneath the road bed to harvest electricity from the vibrations produced due to the vehicles moving on the road.

2-) FUNDAMENTAL UNDERSTANDING OF PIEZOELECTRIC STRAIN SENSOR 

Link: PIEZOELECTRIC STRAIN SENSOR

Info: Strain measurements from piezoceramic (PZT) and piezofilm (PVDF) sensors are comparedwith strains from a conventional foil strain gage and the advantages of each type of sensor are discussed,along with their limitations. The sensors are surface bonded to a beam and are calibrated over a frequency range of 5–500 Hz. Correction factors to account for transverse strain and shear lag effects due to the bond layer are analytically derived and experimentally validated. The effect of temperature on the output of PZT strain sensors is investigated. Additionally, design of signal conditioning electronics to collect the signals from the piezoelectric sensors is addressed.

3-) PIEZOELECTRIC ENERGY HARVESTING DEVICES: AN ALTERNATIVE ENERGY SOURCE FOR WIRELESS SENSORS

Link: PIEZOELECTRIC ENERGY HARVESTING DEVICES

Info: One of the major limitations on performance and lifetime of WSNs is the limited capacity of these finite power sources, which must be manually replaced when they are depleted.Moreover, the embedded nature of some of the sensors and hazardous sensing environment make battery replacement very difficult and costly. The process of harnessing and converting ambient energy sources into usable electrical energy is called energy harvesting. Energy harvesting raises the possibility of self-powered systems which are ubiquitous and truly autonomous, and without human intervention for energy replenishment. Among the ambient energy sources such as solar energy, heat, and wind, mechanical vibrations are an attractive ambient source mainly because they are widely available and are ideal for the use of piezoelectric materials, which have the ability to convert mechanical strain energy into electrical energy.

BLOCK DIAGRAM

METHODOLOGY:

Block Diagram

Piezoelectric Sensor:

A piezoelectric sensor is a device that uses the piezoelectric effect to measure pressure, acceleration, strain or force by converting them to an electrical signal. Other than that,piezoelectric sensor have  different type such as ceramic piezoelectric sensor and quartz crystal piezo sensor. But on this project will be use ceramic piezo sensor.  This project an array of 10 piezoelectric sensors is used for generation of power.

Lead Acid Battery:

Battery (electricity), a variety of electrochemical cells for electricity storage, either independently connected or exclusively connected and housed in a single unit. An electrical battery is a blend of at least one electrochemical cells, used to change stored chemical energy into electrical energy.

ADC (analog digital converter):

An analog-to-digital converter (abbreviated ADC, A/D or A to D) is a device that converts a continuous quantity to a discrete time digital representation. An ADC may also provide an isolated measurement. The reverse operation is performed by a digital-to-analog converter (DAC). Typically, an ADC is an electronic device that converts an input analog voltage or current to a digital number proportional to the magnitude of the voltage or current. However, some non-electronic or only partially electronic devices, such as rotary encoders, can also be considered ADCs.

Microcontroller:

This project uses the AT89S52 Microcontroller and Features of this microcontroller includes 8K bytes ROM, 256 bytes RAM 3) 3 Timers, 32 I/O pins, one Serial port, 8 Interrupt sources Here we are using AT89S52microcontroller to display the amount of battery get charged when we place our footstep on piezoelectric sensor.

Load:

Load on this project it mean output after the battery already charge and test the project using load. Load on this project can be use to charge phone, small fan and also can use a lamp or emergency lamp.