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       Early we saw a slow change from the conventional fuel based vehicles to electric vehicles(EV) .But now the pace had increased .By 2025 EV will hold a good market share Majority of the vehicle manufactures had moved a step into the electric mobility  First among them was the KONA launched by the Hyundai motor Company  in India ,followed by  Tata motors and many more .Currently we can see a lot of fuel pumps in different parts of our cities without much distance between them ,which make  people easy to access .We need to have more charging stations similar to the Conventional fuel pumps .

Most manufactures are producing electric vehicles under the Plug in category ,which are much similar to our mobile phone , which needs to charge and will run till the battery drains out completely and for using it again we need to charge it again .Though few technologies like regenerative braking system helps to recover a very few of the used energy to  restore the power in the battery .it’s not enough to restore the battery completely.

Due to the limited storage power of the batteries , the kilometre range which it can run is limited ,which make people not to choose the electric vehicles

Another major issue is the time taken by the system to recharge the battery to 100% .Most manufacturers are providing household chargers that could be charged using the 240V current , but taking more than 6 charge the batteries completely . High power charging stations are required to recharge the battery at least 80 % .It even take more than 1 hrs .So we need technologies that could charge the battery in less time or systems that could charge the battery while discharging at a higher rate .

The initial cost of the electric vehicles are huge compared to the conventional vehicles ,though it can be covered in less maintenance charges .And issues with the battery also make it a  few persons choice .

New laws are required to frame for the distribution of power through the charging stations .Tax waving or similar method from the government are  required to attract people into the electric vehicles    

 Written by : Stephin John Mathew 

Operating System

Introduction of Operating System

An operating system acts as an intermediary between the user of a computer and computer hardware. The purpose of an operating system is to provide an environment in which a user can execute programs in a convenient and efficient manner.
An operating system is a software that manages the computer hardware. The hardware must provide appropriate mechanisms to ensure the correct operation of the computer system and to prevent user programs from interfering with the proper operation of the system.
Operating System – Definition:
  • An operating system is a program that controls the execution of application programs and acts as an interface between the user of a computer and the computer hardware.
  • A more common definition is that the operating system is the one program running at all times on the computer (usually called the kernel), with all else being application programs.
  • An operating system is concerned with the allocation of resources and services, such as memory, processors, devices, and information. The operating system correspondingly includes programs to manage these resources, such as a traffic controller, a scheduler, memory management module, I/O programs, and a file system.
Functions of Operating system – Operating system performs three functions:
  1. Convenience: An OS makes a computer more convenient to use.
  2. Efficiency: An OS allows the computer system resources to be used in an efficient manner.
  3. Ability to Evolve: An OS should be constructed in such a way as to permit the effective development, testing and introduction of new system functions at the same time without interfering with service.
Operating system as User Interface –
  1. User
  2. System and application programs
  3. Operating system
  4. Hardware
Every general-purpose computer consists of the hardware, operating system, system programs, and application programs. The hardware consists of memory, CPU, ALU, and I/O devices, peripheral device, and storage device. System program consists of compilers, loaders, editors, OS, etc. The application program consists of business programs, database programs.
Conceptual View of a Computer System

Every computer must have an operating system to run other programs. The operating system coordinates the use of the hardware among the various system programs and application programs for various users. It simply provides an environment within which other programs can do useful work.
The operating system is a set of special programs that run on a computer system that allows it to work properly. It performs basic tasks such as recognizing input from the keyboard, keeping track of files and directories on the disk, sending output to the display screen and controlling peripheral devices.
OS is designed to serve two basic purposes:
  1. It controls the allocation and use of the computing System’s resources among the various user and tasks.
  2. It provides an interface between the computer hardware and the programmer that simplifies and makes feasible for coding, creation, debugging of application programs.
The Operating system must support the following tasks. The task are:
  1. Provides the facilities to create, modification of programs and data files using an editor.
  2. Access to the compiler for translating the user program from high level language to machine language.
  3. Provide a loader program to move the compiled program code to the computer’s memory for execution.
  4. Provide routines that handle the details of I/O programming.
I/O System Management –
The module that keeps track of the status of devices is called the I/O traffic controller. Each I/O device has a device handler that resides in a separate process associated with that device.
The I/O subsystem consists of
  • A memory Management component that includes buffering caching and spooling.
  • A general device driver interface.
Drivers for specific hardware devices.
Assembler –
The input to an assembler is an assembly language program. The output is an object program plus information that enables the loader to prepare the object program for execution. At one time, the computer programmer had at his disposal a basic machine that interpreted, through hardware, certain fundamental instructions. He would program this computer by writing a series of ones and Zeros (Machine language), place them into the memory of the machine.
Compiler –
The High-level languages- examples are FORTRAN, COBOL, ALGOL and PL/I are processed by compilers and interpreters. A compiler is a program that accepts a source program in a “high-level language “and produces a corresponding object program. An interpreter is a program that appears to execute a source program as if it was machine language. The same name (FORTRAN, COBOL, etc.) is often used to designate both a compiler and its associated language.
Loader –
A Loader is a routine that loads an object program and prepares it for execution. There are various loading schemes: absolute, relocating and direct-linking. In general, the loader must load, relocate and link the object program. The loader is a program that places programs into memory and prepares them for execution. In a simple loading scheme, the assembler outputs the machine language translation of a program on a secondary device and a loader places it in the core. The loader places into memory the machine language version of the user’s program and transfers control to it. Since the loader program is much smaller than the assembler, those make more core available to the user’s program.
History of Operating system –
Operating system has been evolving through the years. Following Table shows the history of OS.
First1945-55Vaccum TubesPlug Boards
Second1955-65TransistorsBatch Systems
Third1965-80Integrated Circuits(IC)Multiprogramming
FourthSince 1980Large Scale IntegrationPC
  • Batch Operating System- Sequence of jobs in a program on a computer without manual interventions.
  • Time sharing operating System- allows many users to share the computer resources.(Max utilization of the resources).
  • Distributed operating System- Manages a group of different computers and make appear to be a single computer.
  • Network operating system- computers running in different operating system can participate in common network (It is used for security purpose).
  • Real time operating system – meant applications to fix the deadlines.
Examples of Operating System are –
  • Windows (GUI based, PC)
  • GNU/Linux (Personal, Workstations, ISP, File and print server, Three-tier client/Server)
  • macOS (Macintosh), used for Apple’s personal computers and work stations (MacBook, iMac).
  • Android (Google’s Operating System for smartphones/tablets/smartwatches)
  • iOS (Apple’s OS for iPhone, iPad and iPod Touch)

CNC Machine: Advantages, Disadvantages and Applications.

The CNC machine works based on CAD and CAM programs and computer control. CAD (Computer-Aided Design) is drawing software. Also, CAD software is used to increase the productivity of the designer, improve the quality of design, improve communications through documentation, and to create a database for manufacturing. Whereas, CAM (Computer-Aided Manufacturing) having two codes like G-code and M-codes on which all the programs are written and feed into the machine to perform the various operations. (i.e. turning, grooving operation in a lathe).

Advantages of CNC Machine:

Following are the advantages of having a CNC machine:
  • ·       The CNC Machine provides a workpiece with better precision and accuracy.
  • ·       Fewer workers required which helps to saves the labor cost.
  • ·       A high skilled operator not required. Even a trained worker can operate these CNC machines.
  • ·       CNC Machine can produce complex designs with high accuracy in minimum possible time.
  • ·       CNC machine has an online editing program, which means any changes and mistakes in cutting conditions or in dimension can easily be edited and modified by the part data store in the computer without sending the tape for re-processing.
  • ·       The conversion of the unit can easily be done by this machine (SI to British or from British to SI).
  • ·       It can diagnostic its own fault easily, there is a special software enables easy to troubleshoot if the CNC system fails to operate and also having the capability to assist in maintaining and repair the system automatically.
  • ·       It also helps with safety reasons.
  • ·       Low Maintenace required
  • ·       Reduce setup-change over time.
  • ·       The CNC Machine has Higher Production and capability.
  • ·       It can run for 24 hours a day.
  • ·       Reliable.

Disadvantages of CNC Machine:

·       Here are some disadvantages of CNC machine:

  • ·       The installation cost is high.
  • ·       Even do the parts of the CNC machine are high.
  • ·       When any failure occurs in the machine the high skilled profession requires to solve the issue.
  • ·       Computer knowledge is required.
  • ·       Program knowledge is required

Applications of CNC Machine:

These are some applications of CNC Machine:

  • ·       The main application of the CNC machine is to remove metal at a faster rate as compared to a traditional machine-like lathe, milling machine.
  • ·       This is also used in fabrication industries.
  • ·       This machine is used for automatic removal of metal from the workpiece wherein another machine like lathe, Milling the metal remove is done manually.

CNC Machine
This is the actual machine where the finished product made. I already mentioned the parts of the CNC machine above this heading. This is the housing of headstock, tailstock, foot switch, chuck, and tool turret.

How CNC Machine Works?

The above all the details I have explained is all about the CNC machine. The CNC machine works based on CAD and CAM programs and computer control. CAD (Computer-Aided Design) is drawing software. Also, CAD software is used to increase the productivity of the designer, improve the quality of design, improve communications through documentation, and to create a database for manufacturing. Whereas, CAM (Computer-Aided Manufacturing) having two codes like G-code and M-codes on which all the programs are written and feed into the machine to perform the various operations. (i.e. turning, grooving operation in a lathe)

Here is the example of steps:

The first step is, write and Insert the part program which is (G and M code) into the Machine Control Unit of the CNC machine. Now all the data process takes place and according to the program it prepares commands and sends it to the driving system. The drive system controls the motion and velocity of the machine tool. The feedback system records the position and velocity measurement of the machine tool and sends a feedback signal to the MCU. In MCU, the feedback signals are compared with the reference signals and if there are errors, it corrects it and sends new signals to the machine tool for the right operation to happen. The display unit is used to see all the commands, programs, and other important data.

Types of CNC Machine:

  • CNC machines are can be classified into the following types:
  • ·       CNC laser cutting machine
  • ·       CNC Lathe Machine
  • ·       CNC Milling Machine
  • ·       CNC router Machine
  • ·       CNC Plasma Cutting Machine
  • ·       5- axis machine
  • ·       3-D Printer
  • ·       Pick and Place Machine

CNC laser cutting machine:

As the name itself indicates “Laser cutting” it means the cutting operation is carried by laser and the operation code is fed into machine runs automatically, it is called CNC laser cutting machine. This machine is used for sheet cutting. nIt provides a better surface finish. Even do the complicated design can be made in this you just have to feed the program according to it? The machine cost is very high. The major problem face is like when machine parts got damage it takes time to fix because of unavailability in the market.

CNC Lathe Machine:

Before moving further on the CNC Lathe machine I wanna tell you that I have covered Lathe Machine in detail, I have discussed every possible point on the lathe machine you should check it too. Now moving to CNC Lathe machine. CNC stands for Computerized numerically controlled. This is widely used as a lathe in the present time because of its fast and accurate working. It is one of the most advanced types. It uses computer programs to control the machine tool. Once the program is fed into the computer as per the program it starts operation with very high speed and accuracy. Even do preplanned programmed machine is there in which once code is set for the various operations it can starts operation without changing code in the next time. A semi-skilled worker can easily operate this after the initial setup is done. These types of lathes are also used for mass production like capstan and turret but there is no programmed fed system. The components manufactured by these lathes are very accurate in dimensional tolerances.

CNC Milling Machine:

As we know Milling Machine is a process of metal-removing by feeding the workpiece passes through the rotating multipoint cutter. This machine is used to make gears like Spur gears, and also drill the workpiece bore, and produce slots. The same work is performed in CNC Milling by inserting the part program into the system. A semi-skilled worker can easily operate this after the initial setup is done. These types of machines are also used for mass production like capstan and turret but there is no programmed fed system.The components manufactured by this machine are very accurate in dimensional tolerances.

CNC Router Machine:

It works similarly as other CNC machines like lathe or Milling do. The main difference is, it does all the carpenter work manually like such as door carvings, interior and exterior decorations, wood panels, signboards, wooden frames, moldings, musical instruments, furniture, and so on. As per sketch, you can design if possible you can make into the system then execute on this machine. It provides a better surface finish. This will be a very good machine in terms of the design of the door and more.

CNC Plasma Cutting Machine:

The Plasma cutting machine is defined as It is a process that cuts through electrically conductive materials using an accelerated jet of hot plasma. Whereas CNC Plasma cutting machine is defined as the cutting operation are done by a computer numerically controlled system. We studied CNC laser cutting above the main difference between them is, one operation perform by laser which is very costly and whereas the other one is hot plasma which is less costly and these are portables. As the industry grows, new technology is invented these are one of them. Provide a better surface finish.

5- axis machine:

It is a machine in which there is a total of 5 axes.  Initially, it was 3 axis (X, Y, and Z) the cutting operation of any instrument was done in the 3 direction but 2 additional axes added (A, B) which means there are total 5 axes, works are cut are done in the 5 direction. 5 The Axis machine is used for making sculptures.

3-D Printer:

3D Printer is a CNC machine in which the metals are printed layer by layer. The 3D printer works for the printing of buildings and complexes. The design and drawing are made by the CAD and CAM process and then 3D Printer works for visualizing that design.

Pick and Place Machine:

This is another great type of machine. It is used in the industry. Let’s understand by a simple example. The company Amazon having a warehouse where it used to keep a large quantity of the items. If the items are adjusted manually it takes a great time to avoid that this machine introduces to pick and place the items.

Elements of the CNC Machine system
A CNC machining system is consists of the following elements:
·       Program
·       Tape Reader
·       Mini-computer
·       Servo system
·       CNC machine tool

This is entered into the computer through a keyboard. These are the codes used to control the machine. The various CNC codes are N Code, G Code, XYZ Code, F code, etc
Tape Reader:
This is used as a storage device where we can store the program for a particular machining operation. Any modification of a program can easily be done by editing the existing program as per your requirement.
It is also called the machine control unit. It is to read interprets and converts perceived input that is part program into the desired movement and controls the following functions:
·       To start and stop the machine spindle.
·       Vary the spindle speed accordingly and also it can control the direction of rotation of the spindle.
·       To start and stop the coolant supply.
·       To change the required tools as per requirements.
·       To change the workpiece.
·       To control the feed rate.
Also, the mini-computer equipped with diagnostic software which can detect any problem and restore the machine accordingly.
Servo system:
The function of the servo system is to receive the control signal from the feedback devices and the set output accordingly (To shaft, tools and other components of CNC machine)
Servo system mainly consists of:
·       Servo Motors
·       Feed-back devices
·       Ball screws

CNC machine

CNC machine can be defined as the machine which is control by computer and the operation is performed by feeding the program on it. CNC machine operates on only two subjects which are CAD and CAM. CAD stands for Computer-aided design. This subject helps you to learn about the design of a machine and machines tools. CAM stands for Computer-aided manufacturing. This subject is also similar to CAD but it deals with manufacturing whereas CAD deals design.
Parts of CNC Machine:
A CNC machine is consists of the following parts:
·       Bed
·       Headstock
·       Tailstock
·       Tailstock quill
·       Footswitch or pedal
·       Chuck
·       Control panel
·       Tool turret
Let’s go into details.

The bed is kind of hardened parts of a machine because The tool turret travels over the CNC lathe bed, kind of machining can’t affect them.
The headstock is the main part of the machine, here the workpiece is fixed to perform an operation and also Headstock of a CNC lathe machine has the main motor which drives the main spindle.
The tailstock is for providing extra grip to the workpiece. When the operation like knurling, threading has performed these parts used to hold the workpiece.
Tailstock quill:
This is kind of setting the workpiece between the centers.
Footswitch or pedal:
Through these pedals, CNC machinist’s open and close the chuck to grip the component, the same way tailstock quill is taken to forward position or reversed.
Chuck is mounted on the main spindle. Here we fixed the workpiece.
Control panel:
The control panel is another main part of the CNC machine in which we use to set or feed the program for the operation we perform on the workpiece. This is also called the brain of a CNC machine.
Tool turret:
The tool is mounted on the tool turret which is used for component machining. Tool turrets vary in shapes and the number of tools that can be mounted on them. These are the Parts of CNC machine, now I will talk about the CNC system.