Automation In Manufacturing System

Manufacturing Automation is a key technology necessary for improving the quality and quantity of manufactured products.This technology is specially important in developing countries due to the shortage of skilled workers in those countries.Several automatic techniques are available for detecting faults in different machine components and locating the immediate faulty areas.Computer Numerical Control(CNC)machines,robots,surface milling machines,lathes and compressors are among hundreds of widely used machines in manufacturing.Every one of these tools is designed with the idea of repetition in mind.On an assembly line,each component repeats a task over and over again,most of the time without a break.The cost associated with manufacturing a piece is multiplied by hundreds and thousand of pieces manufactured at site.These pieces could be related to automobiles,refrigerators,toys,pharmaceuticals,clothing,computers etc.Precision has found more and more demand everyday for the past decade.Due to great amounts of competition in the line of manufacturing,unlike the past,only companies with the best products survive.

Due to the repetitive nature of manufacturing,most people working in these sites become more and more valuable for the creation of their product.This is due to the fact that they gain experience and their productivity increases with their experience.Unfortunately, one cannot say the same thing about most machines on the assembly line.They start wearing out and they hardly learn anything from their past experiences.In an optimal manufacturing process,it is desirable for the system to learn and improve its performance with experience.It is also desirable that any components of the system which are no longer performing optimally should be found and reported to the human supervisor in an automatic manner so that they could be replaced with a new piece.

Controls In Manufacturing

A wide class of controllers in this employ predefined gains and do not take into consideration the nonlinear dynamics in these machines. [1, 2] These gains are based on linear approximations of these highly nonlinear systems and are tuned to different tasks manually.These tuning jobs usually take hours and sometimes days and during this time the machines are not operable.The result is that these machines are not utilized to their full potential in terms of speed and precision.With a more sophisticated control strategy,it is possible to compensate for the complicated effects of nonlinearities which have in the past been considered as disturbances in most systems.Two classes of newly developed control systems which are mostly geared toward manufacturing applications are called Repetitive and Learning control systems.A repetitive controller [15, 16] is designed for processes which operate in cycles.Repetitive controllers assume that there is continuity between the last point of a repetition and the first point of the next repetition.In Learning Controllers the initial conditions are reset to the same value at each repetition.The Learning Self-tuning Regulator has also shown both in computer simulations and in experimental setups to be highly robust and to reduce the total error of systems by considerable amounts.

Another important need of manufacturing systems is to be able to monitor different components automatically.Lots of research has been done in this area in the past decade.The health of components such as bearings could be monitored by placing inexpensive accelerometer on the body of the machine.Similar type of research has been done for monitoring compressors which could seriously malfunction and blow up in cases.Automatic monitoring systems could shut these systems down before they could cause any danger.In such cases,lives might be saved using these automatic monitors.

Using these new technologies in control and monitoring of manufacturing processes could be very practical and valuable.Using these techniques,better quality products could be manufactured in addition to the increased speeds of production.The down-time of manufacturing processes is reduced extensively using condition monitoring techniques and the expertise of human workers could be used in much more useful ways.Perfect integration of the above techniques could amount to an optimal manufacturing process. 

PHOTOVOLTAIC

Photovoltaic (PV) devices generate electricity directly from sunlight via an electronic process that occurs naturally in certain types of material, called semiconductors. Electrons in these materials are freed by solar energy and can be induced to travel through an electrical circuit, powering electrical devices or sending electricity to the grid.PV devices can be used to power anything from small electronics such as calculators and road signs up to homes and large commercial businesses.

How does PV technology work?
Photons strike and ionize semiconductor material on the solar panel, causing outer electrons to break free of their atomic bonds. Due to the semiconductor structure, the electrons are forced in one direction creating a flow of electrical current.Solar cells are not 100% efficient in Diagram of a typical crystalline silicon solar cell. Solar cells are not 100% efficient in part because some of the light spectrum is reflected, some is too weak to create electricity (infrared) and some (ultraviolet) creates heat energy instead of electricity.

Others types of Photovoltaic Technology
Thin Film PV is a fast-growing but small part of the commercial solar market. Many thin-film firms are start-ups developing experimental technologies. They are generally less efficient but often cheaper than c-Si modules. 
In the United States, concentrating PV arrays are found primarily in the desert Southwest. They use lenses and mirrors to reflect concentrated solar energy onto high-efficiency cells. They require direct sunlight and tracking systems to be most effective 
History of Photovoltaic Technology
The PV effect was observed as early as 1839 by Alexandre Edmund Becquerel, and was the subject of scientific inquiry through the early twentieth century. In 1954, Bell Labs in the U.S. introduced the first solar PV device that produced a useable amount of electricity, and by 1958, solar cells were being used in a variety of small-scale scientific and commercial applications.The energy crisis of the 1970s saw the beginning of major interest in using solar cells to produce electricity in homes and businesses, but prohibitive prices (nearly 30 times higher than the current price) made large-scale applications impractical.Industry developments and research in the following years made PV devices more feasible and a cycle of increasing production and decreasing costs began which continues even today.

Most modern solar cells are made from either crystalline silicon or thin-film semiconductor material. Silicon cells are more efficient at converting sunlight to electricity, but generally have higher manufacturing costs. Thin-film materials typically have lower efficiencies, but can be simpler and less costly to manufacture. A specialized category of solar cells - called multi-junction or tandem cells - are used in applications requiring very low weight and very high efficiencies, such as satellites and military applications. All types of PV systems are widely used today in a variety of applications.
 In most parts of India sunlight and wind is available in abundance for generating energy. While solar energy generation is quite predictable and will occur only during the daylight hours, wind energy is location specific. Complementing solar and wind energy with batteries and diesel generators will ensure uninterrupted supply of power. All our systems are designed to maximize the use of renewable energy thereby reducing dependence on fossil fuels.

Google's Loon

Project Loon is research and development project being developed by Google with mission of providing Internet access to rural & remote areas.The project uses high altitude balloons placed in the stratosphere at an altitude of about 32 Km to create an aerial wireless network using a special internet antenna attached to their building.The signal travels through the balloon to balloon then ground based station connected to Internet Service Provider(ISP),then onto the global Internet.The system aims to bring Internet access to remote & rural areas poorly served by existing provisions & to improve communication during natural disasters to affected regions.

The technology designed in the project could allow countries to avoid using expensive fiber cable that would have to be installed underground to allow users to connect to the internet.Google feels this will greatly increase internet usage in developing countries in regions such as Africa & Southeast Asia that can't afford to lay underground fiber cable.Project Loon balloons positioned in the stratosphere wind at an altitude of about 20 Km,twice as high as airplane flights & weather changes.It is situated on the edge of space between 10 Km & 60 Km in altitude having steady wind below 20 mph.This spherical layer is great for solar panels because there are no clouds to block the sun.

Each balloon has a radio antenna that provide constant connectivity to the ground and connects each balloon to other balloon.There is special ground antenna that is installed on the home or workplace to access the internet from balloon.Google claims that each balloon can provide signal connectivity to ground area about 40 Km in diameter & able to deliver 3G comparable speeds.These antenna uses ISM bands of spectrum 2.4 GHz & 5.8 GHz.

There are two types of communications:1.Balloon to Balloon Communication.

                                                            2.Balloon to Ground Communication.

In loon design there are three main components

1.Envelope:The inflatable part of the balloon is called Envelope.Each super pressure balloon is made of polyethylene plastic material & filled with helium.When fully inflated the balloon height is 12 m & it's width is 15 m.The envelope is designed to resistant exposure to UV rays & is capable to function at dramatic temperature swing as low as -80 degree celsius. 

2.Solar Panel:Each balloon's solar panel provide power to it's own electronics.The solar panel's mounted at a steep angle to effectively capture sunlight.The panel produce approximately 100 watts of power in full sun & additional power is stored in rechargeable batteries.

3.Electronics:A small electronic box hangs underneath the inflated envelope.This box contains circuit boards,Linux based computer,radio antenna,GPS sensors & batteries.They have specific function.circuit boards to control the system,radio antenna for communication,GPS for tracking location,sensors to monitor and record weather conditions & lithium ions batteries to store solar panel.

Internet connectivity & communication become one of the basic needs in modern human daily life.An innovative idea like the Google's Project Loon would aid & benefit remote area of the world.It would also provide backbone communication during & after natural disaster when ground infrastructure is destroyed.