Computer Application in Textiles-1 vignesh dhanabalan(pavitra)

Computer Applications in Textiles Unit - I

The Computer System

A Computer can be viewed as a system that comprises several units. The term ‘computer system’ refers to the whole of computer hardware, peripherals, and data communication equipment. It consists of a number of interrelated components that work together with the aim of converting data into information. Computer Architecture is defined as the science of selecting and interconnecting hardware components to create computers that meet functional, performance and cost goals. It is otherwise known as the manner in which the hardware components of the system are interconnected.

Central processing unit

A computer system essentially has three important components:

1. Central Processing Unit (CPU): This unit performs processing of instructions and data inside the computer.

2. Input Unit: This component of the computer accepts instructions and data.3. Output Unit: This unit communicates the results to the user.

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Memory unit

Control unit Arithmetic / Logic Unit

Input Unit Output Unit


Central Processing Unit (CPU)

The Central Processing Unit or CPU is the ‘administrative’ section of the computer system. It interprets, coordinates the operations and supervises the instructions. The CPU contains the circuits that decode and execute instructions. CPU works with data in discrete form, that is, either 1 or 0. It counts, lists, compares and rearranges the binary digits of data in accordance with the detailed program instructions stored within its memory. The results of these operations are translated into characters, numbers and symbols that can be understood by the user. The circuits necessary to create a CPU for a personal computer are fabricated on a microprocessor. Some of the basic functions of a CPU are

It issues commands to all parts of the computer system. It controls the sequence of operations as per the stored instructions. It stores data as well as programs. It performs the data processing operation and sends the results to the output unit.

The central processing unit itself has three parts

1. Arithmetic Logic Unit (ALU) - This unit performs the arithmetical and logical operations on the stored numbers. The data is transferred from the memory unit to the arithmetic logic section, processed and returned to internal storage. Before the completion of the processing, data may be transferred back and forth between these two sections, several times. Subsequently, the results are transferred from internal storage to an output device.

2. Control Unit - This unit checks the correctness of sequence of operations. It fetches the program instruction from the primary storage unit, interprets them, and ensures correct execution of the program. It also controls the input / output devices and directs the overall functioning of the other units of the computer.

3. Memory Unit – This unit holds the intermediate results during the course of calculations and provides the data as and when required. It stores the program instructions and data on which the processor is currently working. This internal storage section is also called as primary memory or main memory. The storage section takes the data from an input device and stores it until the computer is ready to process it. It also stores processed data and intermediate results. When the processing is finished, it transfers the final results to an output device.

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Input, Output and Storage Units

A computer system also incorporates input and output devices which are a communication medium between a human and the computer. An input unit accepts instruction and data from the user and communicates them to the computer. The basic task of this unit is to gather the data and convert it into the form that the computer can understand. Some of the input devices are keyboard, mouse, light pen, and so on.

Just as humans communicate with computers with input devices, the computer can communicate with human beings with the help of output devices. Like input units, output units are instruments of interpretation and communication between humans and computers. These devices take the machine-coded output results from the processor and convert them into a form that can be used by the people or as a machine input in another processing cycle. Some of the commonly used output devices are printers, monitor and plotters.

The three units of CPU and the input/ output devices form the five important components of a computer system. In addition to these parts, a computer also employs secondary storage devices which are extensively used for storing data or instructions. The physical components or materials on which data stored permanently are called storage units or devices. It supplies the stored information to the other units of computer as and when required. Some common storage devices are floppy disks, hard disks, and tape drives.

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PRACTICE

1. Objective type questions

1. Computer architecture is known as the manner in which the components of the system are interconnected.

(a) Software (c) Central Processing Unit

(b) Hardware (d) Input/output devices

2. is the ‘administrative’ section of the computer sytem.

(a) CPU (c) ALU(b) Input unit (d) Memory unit

3. The basic task of this unit is to gather the data and convert it into the form that the computer can understand.(a) Output unit (c) Control unit(b) Storage unit (d) Input unit

4. This unit holds the intermediate results during the course of calculations and provides the data as and when required.(a) Memory unit (c) Input unit(b) Output unit (d) Control unit

5. These are instruments of interpretation and communication between humans and computers.(a) ALU (c) Input/output units(b) Control unit (d) Storage unit

2. 2 marks questions

1. Define Computer architecture.2. What are the components of a computer system.3. What are the basic functions of CPU?4. What does the control unit do in a computer system?

3. Descriptive type questions

1. Explain with a block diagram the components of a computer system and their functions.

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SPREAD SHEET

The instructions fed to the computer in the form of sheet are called as a spreadsheet.It requires

One MB of RAM Compatible running in MS – DOS version 3.0 Hard disk Graphics display

It contains 3 types of program

Spread sheet program Graphics program Database management system program

One of the most popular spread sheet package is Lotus 123, written in C language.

Specialties of package:

Multipage spread sheets Multiple active work sheets Supports operating system Display graphs and data simultaneously

Lotus 123 is a software which has been developed for use a person with no special knowledge about computer and programming language.

Spread sheet program:

Spread sheet electronically duplicates on accountance book keepers tool. It is having a Ledger bag, pencil, eraser, and calculator. Data can be entered through key board and it displays on monitor The datas once entered on spread sheet can be applied for variety of calculations.

Graphics Program:

Graphics program which enables you to create various graphs like bar or line graph from the information on work sheet.

DBMS Program:

Using DBMS program, Lotus 123 can instantly retry or reorganize all the information without consuming time by turning pages or searching through files.

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Electronic Spread Sheet

Electronic spread sheet is basically contains a table of rows and coloumns. It has enhanced flexibility, speed and accuracy.

Name of some of the package

Old Visicak, supercal

New Lotus 123 and Excel 4.

It contains a 256 rows and 8192 colums.

First 26 columns A to Z

Next 26 columns AA to AZ

Next 26 columns BA to BZ

Application:

Accounting Banking Finance and Economics Marketing Personal Administration Retail Merchandising Statistics

Working with electronic spread sheet changing the content of the cell

User moves the cursor around the electronic spread sheet changing the value of current cell.

While typing a formula on the cell, it will be displayed on the top of the screen. To change the content of the cell, the cursor can be moved to the cell and the new

content can be entered. The old content is lost and the new value is entered. Any cell value that depends on the value of the changed cells is recalculated.

Editing of Spread sheet

After saving the current content on the disc, the spread sheet can be recalled at any time later.

User can erase the content of a single cell or of entire rectangular blocks of the cell.

They can automatically adjust the formula from one cell to another cell.

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WORD PROCESSOR

Word Processing is a computer term for typing and editing any kind of letters and memos, articles , reports etc,.

Facilities of word processing:

Document creation, storage and editing Automatic page numbering, centuring,underlining,overtyping and reformatting

and right justification. Efficient search Global search and replace. Spelling change, sorting and graphics Calculation and password security

Advantages of Word Processor

Increase the office efficiency Higher quality output Improved human resource utilization with better control Faster output speed Reduction in amount of proof reading required The elimination of stationary wastage

Features of word processor

Basic features are

1. Preparation, editing, formatting and printing of letters2. Automatic form filling3. Filling and searching of large information stocks.

Advance features are

1. Shared with the large number of terminals2. Shared resource systems

Application of word processor

I. A unique reportApart from assisting a typist with the ease of moving through the text, backwards and forwards, looking for the parts to edit, a word processor enables automatic headings and footings, page numbering, bold printing and underling facilities etc,.

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II. Report workThe standard documents which are used often with slight portion specifically written and rest of it common in general. It can be done using word processing in a minor time.

III. Mailing ListWhen one need a document or letter which has some part common and some fields are changed for different documents. This work can be done by designing a database of having different fields and using the mail merge facility of the word processor.

Word Processing Programs

Commands to the word Processor

i. Text Storageii. Text Display

iii. Text Editingiv. Insertionv. Over Typing

vi. Deletevii. Move

viii. Copy and Insertsix. Formatting and Printingx. Headers and Footers

xi. Rules and Tabsxii. Special printing effect

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PRACTICE1. Objective type questions

1. This program can be used to instantly retry or reorganize all the information without consuming time by turning pages or searching through files.

(a) Graphics (c) Spread Sheet

(b) DBMS (d) C-program

2. This is a computer term for typing and editing any kind of letters and memos, articles, reports.

(a)Word processing (c) Signal processing

(b) Data processing (d) Image processing

2. 2 mark questions1. What are the requirements of spread sheets?2. What are the specialities of spreadsheets?3. What is a spread sheet program?4. State few applications of spread sheets.5. What are the advantages of word processor?6. Write about the basic and advanced features of word processor.

3. Descriptive type questions1. What are spread sheets? Write about the its features and advantages.2. Write notes on the applications of word processor.

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Database management system (DBMS)

A DBMS is a set of software programs that controls the organization, storage , management, and retrieval of data in a databaseSystem for quick search and retrieval of information from a database. The DBMS determines how data are stored and retrieved. It must address problems such as security, accuracy, consistency among different records, response time, and memory requirements. These issues are most significant for database systems on computer networks. Ever-higher processing speeds are required for efficient database management.

DataBase Management System) Software that controls the organization, storage, retrieval, security and integrity of data in a database. It accepts requests from the application and instructs the operating system to transfer the appropriate data. The major DBMS vendors are Oracle, IBM, Microsoft and Sybase (see Oracle database, DB2, SQL Server and ASE). MySQL is a very popular open source product (see MySQL).

DBMSs may work with traditional programming languages (COBOL, C, etc.) or they may include their own programming language for application development.DBMSs let information systems be changed more easily as the organization's requirements change. New categories of data can be added to the database without disruption to the existing system. Adding a field to a record does not require changing any of the programs that do not use the data in that new field.

Major Features of a DBMS

Data SecurityThe DBMS can prevent unauthorized users from viewing or updating the

database. Using passwords, users are allowed access to the entire database or a subset of it known as a "subschema." For example, in an employee database, some users may be able to view salaries while others may view only work history and medical data.

Data IntegrityThe DBMS can ensure that no more than one user can update the same record at

the same time. It can keep duplicate records out of the database; for example, no two customers with the same customer number can be entered.

Interactive QueryA DBMS provides a query language and report writer that lets users interactively

interrogate the database. These essential components give users access to all management information as needed. See query language and report writer.

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http://encyclopedia2.thefreedictionary.com/report%20writer

http://encyclopedia2.thefreedictionary.com/query%20language

http://encyclopedia2.thefreedictionary.com/MySQL

http://encyclopedia2.thefreedictionary.com/ASE

http://encyclopedia2.thefreedictionary.com/SQL%20Server

http://encyclopedia2.thefreedictionary.com/SQL%20Server

http://encyclopedia2.thefreedictionary.com/DB2

http://encyclopedia2.thefreedictionary.com/Oracle%20database

http://encyclopedia2.thefreedictionary.com/network%2C+computer

http://encyclopedia2.thefreedictionary.com/database

http://en.wikipedia.org/wiki/Database

http://en.wikipedia.org/wiki/Data

http://en.wikipedia.org/wiki/Information_retrieval

http://en.wikipedia.org/wiki/Computer_storage

http://en.wikipedia.org/wiki/Organization

http://en.wikipedia.org/wiki/Software_program


Interactive Data Entry and UpdatingA DBMS typically provides a way to interactively enter and edit data, allowing

you to manage your own files and databases. However, interactive operation does not leave an audit trail and does not provide the controls necessary in a large organization. These controls must be programmed into the data entry and update programs of the application.

This is a common misconception about using a desktop computer DBMS. Creating lists of data for a user's own record keeping is one thing. However, although complete information systems can be developed with such software, it cannot be done without understanding how transactions and files relate to each other in a business system (see Database Design below). In addition, some type of programming is required, whether at a graphical drag and drop level or by using traditional languages.

Data IndependenceWhen a DBMS is used, the details of the data structure are not stated in each

application program. The program asks the DBMS for data by field name; for example, a coded equivalent of "give me customer name and balance due" would be sent to the DBMS. Without a DBMS, the programmer must reserve space for the full structure of the record in the program. Any change in data structure requires changing all application programs

Database Design

A business information system is made up of subjects (customers, employees, vendors, etc.) and activities (orders, payments, purchases, etc.). Database design is the process of organizing this data into related record types. The DBMS that is chosen is the one that can support the organization's data structure while efficiently processing the transaction volume.

Organizations may use one kind of DBMS for daily transaction processing and then move the detail to another DBMS better suited for random inquiries and analysis.

Overall systems design decisions are performed by data administrators and systems analysts. Detailed database design is performed by database administrators.

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CLASSIFICATION OF DBMS

Hierarchical, Network & Relational

Information systems are made up of related files: customers and orders, vendors and purchases, etc. A key DBMS feature is its ability to manage these relationships.

Hierarchical databases link records like an organization chart. A record type can be owned by only one owner. In the following example, orders are owned by only one customer. Hierarchical structures were widely used with early mainframe systems; however, they are often restrictive in linking real-world structures.

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Organisation

Superior Staffs

Technical Department

Finance Department

Managers

Personnel Department

Managers

Technicians

Managers Engineers

Superior Staffs


In network databases, a record type can have multiple owners. In the example below, orders are owned by both customers and products, reflecting their natural relationship in business.

Relational databases do not link records together physically, but the design of the records must provide a common field, such as account number, to allow for matching. Often, the fields used for matching are indexed in order to speed up the process.

In the following example, customers, orders and products are linked by comparing data fields and/or indexes when information from more than one record type is needed. This method is more flexible for ad hoc inquiries. Many hierarchical and network DBMSs also provide this capability.

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CollegeCollege

EnglishEnglish Computer Science

Computer Science

MathematicsMathematics ChemistryChemistry


Object Databases

Certain information systems may have complex data structures not easily modeled by traditional data structures. An "object database" can be employed when hierarchical, network and relational structures are too restrictive. Object databases can easily handle many-to-many relationships.

Intelligent Databases

All DBMSs provide some data validation; for example, they can reject invalid dates or alphabetic data entered into money fields. But most validation is left up to the application programs.

Intelligent databases provide more validation; for example, table lookups can reject bad spelling or coding of items. Common algorithms can also be used such as one that computes sales tax for an order based on zip code.

When validation is left up to each application program, one program could allow an item to be entered while another program rejects it. Data integrity is better served when data validation is done in only one place. Mainframe DBMSs were the first to become intelligent, and all the others followed suit.

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DBMS and OS Interaction

This diagram shows the interaction between the DBMS with other system and application software running in memory.

PRACTICE

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1. Objective type questions1. It must address problems such as security, accuracy, consistency among

different records, response time, and memory requirements.(a) Spread sheets(b) Word processor(c) DBMS(d) MS Office

2. (i) DBMS will not work with traditional programming languages.(ii) DBMS may include their own programming language for application development.

(a) (i) is correct and (ii) is incorrect(b) (i) is incorrect and (ii) is correct(c) (i) and (ii) are incorrect(d) (i) and (ii) are correct

3. The DBMS can prevent unauthorized users from viewing or updating the databse and it is termed as

(a) Data Security(b) Data Integrity(c) Data Independence(d) Database Design

4. This links records like an organization chart.(a) Network database(b) Relational database(c) Object database(d) Hierarchical database

5. This type of database can have multiple owners(a) Network database(b) Relational database(c) Object database(d) Hierarchical database

6. This type of database does not link records together physically but the design of the records must provide a common field.

(a) Network database(b) Relational database(c) Object database(d) Hierarchical database

7. An can be employed when all the other data structures are too restrictive.

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(a) Network database(b) Relational database(c) Object database(d) Hierarchical database

8. Mainframe DBMS were the first (a) Intelligent database(b) Relational database(c) Object database(d) Hierarchical database

2. 2 marks questions1. What do u mean by DBMS?2. Name the major features of DBMS.3. What is Data Integrity?4. What is Data Security?5. What do you mean by Interactive Query?6. What is Data Independence?7. What is a Database Design?8. What are the models of DBMS?


1. What is a Database Management System? Write in detail about the major features of DBMS.

2. Write in detail about the Classification of DBMS.

Microprocessor

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It is a silicon chip that contains a CPU. In the world of personal computers, the term microprocessor and CPU are used interchangeably. At the heart of all personal computer and most workstations sits a microprocessor. Microprocessors also control the logic and almost all digital devices from clock radios to fuel-injection systems for automobiles.

The three basic characteristics that differentiate microprocessors are

Instruction set: The set of instructions that the microprocessor can execute. Bandwidth: The number of bits processed in a single instruction. Clock speed: Given in megahertz (MHz), the clock speed determines how many

instructions per second the processor can execute.

In both cases, the higher the value the more powerful the CPU is. For example, a 32-bit microprocessor that runs at 50MHz is more powerful than a 16-bit microprocessor that runs at 25MHz. In addition to bandwidth and clock speed, microprocessors are classified as being either RISC (Reduced Instruction Set Computer) or CISC (Complex Instruction Set Computer).

Block Diagram of Micropprocessor:

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Primary Memory ROM and RAM

Input Devices

keyboard mouse

Scanner

Light pen

Joystick

Output devices Monitor

Plotters

Printer

Cameras

Secondary Storage

Hard disks

Floppies

CD ROMs DVDs

CPU

Microprocessor


The above sketch is a block diagram of Microprocessor based Computer. Each box indicates a functional unit of the computer hardware. Below each box label is a list of the actual physical entities that can stand for that functions al unit in an actual computer. The lists are by no means complete but do include the most likely choices. The arrows show the directions in which information( data and programs) can move among the different units.

A modern microprocessor based computer has a CPU capable of 4 billion operations per second, a minimum of 512 mega bytes – upgradeable to 4 giga bytes – of primary RAM, 80 to 360 giga bytes of secondary storage( hard disk), a monitor with resolution up to 1200 by 1024 pixels, with 16 million colours and a key board and a mouse. A variety of printers are available along with a host of auxillary input, output and storage devices like scanners, CRROM’s/DVD ROM’s, plotters, cameras, digitisers etc.,

The microprocessors are used for monitoring and controlling of blending and cleaning and waste removal operations

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Blending:

The microprocessor are used in Multimexers or Blenders to monitor and control the dosage of tufts to each compartment and thus ensure constant delivery to the opener/cleaner.

Principle of working of microprocessor based modern mixing/ blending machine:

Each chute consists of an independent dosage system. The system consists of a feed rollers, one is fixed and the other is pressed against the fixed one by a constant force. The distance between the two rollers is measured 5 times per second on both sides. The deviations in the cross-sectional area due to fluctuations in material density are sensed and the input is given to the microprocessor, which processes it and generates an output, which is given to the Inverter to vary the motor speed and in turn the feed roller speed to correct the feed rate. Hence the flow of mass per unit time from each chute is maintained constant.

Cleaning and waste removal:

ABC Control is user – friendly microprocessor based system used to set, monitor and control the ‘Cleaning Intensity’ and ‘Waste Level’. Based on the desired values for cleaning intensity (0 – 1) and waste level ( 1 – 10 %) input through the keyboard of control panel, the ABC control with the help of ‘Varioset Cleaning Field” automatically changes the beater speed and/or the grid bar angle so that the required level of waste extraction and cleaning intensity are achieved while the machine is in running condition.

Very easy operation

Two values are entered at the VarioSet: cleaning intensity as a value between 0.0 and 1.0 and relative volume of waste as a value between 1 and 10.These values are entered on the machine itself or loaded via the ABC Control system. The machine settings are made automatically, even while the machine is running. The settings are reproducible. This provides a high level of operating convenience when batch changes are frequent.

Carding :

In carding process the Microprocessors and Electronic Control Systems are being used for monitoring and control of feed rate, sliver count and nep level.

In Trutzschler/ Trumac cards(D K series) the feed table with feed roller forms the unit. The feed table is provided with the system for scanning of tuft known as CORRECTAFEED CFD. The feed table is provided sensors, which detect via pedal

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levers the variations in the tuft web. The sensors transmit these signals to the electronic control system for correction of feed roller speed and thus uniform feed is ensured.

The CORRECTACARD CCD serves for a long – term regulation and monitoring of sliver count. The sliver trumpet on the calendar unit is fitted with a measuring lever, awhich is linked with a displacement detector(sensor). The measuring lever measures the thickness of card sliver and converts this information via displacement detector into an electrical signal, which is transmitted to the control system. On the basis of the difference between the pre-selected target value and the measured value of the sliver count, the speed of the feed roller is altered by a controller and thus the sliver count is regulated. This is known as long-term autolevelling. Thus the modern card has both open – loop and closed – loop Autolevellers.

On DK 803 card, NEPCONTROL NCT scans the web for neps in the zone between the strip roll and the squeeze rollers. This constant nep monitoring system besides giving an estimate of the nep level in the card sliver actuates the grinding operation in the event of a significant increase nep level from the target value. Hence it assists in monitoring and control of card slikver quality.

Drawing:

In drawing process the electronic systems, namely AUTOLEVELLERS are used for monitoring and regulation of sliver count. On most of the Drawframes open – loop autolevellrs is being used.

An Autoleveller is an electronic device that levels out the mass variations in the input to produce a uniform output. There are two types of Autolevellers namely ‘open-loop ‘ and the ‘closed – loop’ Autolevellers.

In open – loop Autolevellers, the measuring sensor is situated in the feed side before the drafting system. The input mass variations sensed are compared with the set value and the signal generated is given to the circuit, where it is processed electronically and the output signal is given to the change the draft in the back zone and thus to level out the mass variations. The open- loop autoleveller is popularly used on the drawframe, however it lacks self – monitoring.

The close - loop autoleveller has the sensing unit situated in the outpuit side to measure the mass variations of the delivery material. The disadvantage of this system is that the correction is given to the region following the sensed region in the material.

The scanning rollers scan the throughput mass and compares with the set value. The signal generated due to difference between actual value and set value if fed to the electronic circuit, where it is being processed. The output of the autoleveller is given to

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the servo motor to change the speed of the middle and/or back drafting rollers, so that the draft is varied to correct the variations in the input mass. The correction times are in the range of few milliseconds and the correction length lies in the range of few centimeters. Thus a uniform sliver is produced by the autoleveller drawframe. Drawframe can be checked for leveling quite frequently. The accuracy shall lie in the range of ±0.5%.

Spinning

In the ring spinning, Computer system are used for monitoring and controlling of spinning operation. The popular ones are the Uster RINGDATA system, Premier Ring Eye 5000, Uster MILLDATA system, Mill I Automatic Data Acquistion System and EXPERT ERP solution used for process and machine monitoring and control, data acquisition, planning, information management, etc.,

Ring Eye 5000 is a single spindle production and quality monitoring system. As ring spinning department is the most capital, labour , power and variation intensive department in a spinning mill and also as the margins for a spinner are reducing, Ring Eye is the tool designed to derive the maximum out of the available resources.

Ring Eye helps in achieving this by round – the – clock monitoring of spindle – wise end breaks and speed, spindles with repeated breaks, spindles with speed deviation and by providing a history and summary of production and stops. Ring Eye is available with the software PanorAmilL for customized report formats, numerical/graphical reports and long term storage and analysis.

The provision of Optispeed 500 with ABC system helps in monitoring and controlling end breaks through automatic control of spindle speed on ringframe. It provides optmised speed profile, acquires end breakage information automatically from Premier Ring I and helps in maintaining uniform workload through constant end breakage rate.

The Mill Automatic Data Acquisition system helps in automatic data integration from laboratoty tersters, preparatory and spinning machines and automatic winders enabling generation of consolidated quality report in a single sheet, quality and productivity comparisons between machines, material type, etc. It also enables Lot wise Quality Consolidation, Tracking of Quality Deviations to its source, Data export facility, Effective manpower utilisation, and Integration with a wider MIS/ERP system.

EXPERT ERP Solution represents a specialized ERP solution for Spinning Mills. It helps in optimum raw material selection methodology to ensure yarn quality consistency. It has a unique identification system for lot tracking through the entire spinning process. It helps in intergration to automatic data acquisition system from the production machinery. It represents a closed loop quality control system with provision to

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plan, inspect and control quality at every stage. It enables integration of production and quality data for critical component replacement. It contains the spinning process knowledge inbuilt in all technical functions. It has got various modules, like Raw Material Managaement, Production planning, Production, Quality Management, Maintenance and Utilities, Materials Management, Sales, Finance, Payroll and Human Resources.

Application of Computers in Yarn Testing

Computers find extensive applications in testing and quality control of yarns.

Measuring head

Yarn Computer System

The figure shown gives a schematic view of the Evenness Tester with computer system for measurement of yarn unevenness, imperfections and hairiness.

The signal obtained from the measuring head is processed and the application software with calculator performs the following functions

1. Calculation of various yarn parameters like U%, CV%, CV1m, CV3m, CV10m, imperfections per kilometer and the hairiness index.

2. Display of results on the screen

3. Display of results in the form of diagram, spectrogram, VL curves etc.,

4. Recording, storing and retrieving of results.

PRACTICE

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Signal Processor

Display Unit

Recorder/Printer



1. The set of instructions that the microprocessor can execute

(a) Bandwidth

(b) Instruction set

(c) Clock speed

2. This determines how many instructions per second the processor can execute

(a) Bandwidth

(b) Instruction set

(c) Clock speed

3. ABC Control is user – friendly microprocessor based system used to set, monitor and control the ‘ tuft size’.

(a) The above statement is correct

(b) The above statement is incorrect.

4. In carding process the microprocessors are used for monitoring and control of

(a) Feed rate, Sliver count and nep level

(b) Cleaning intensity

(c) Waste level

(d) Tuft size

5. The feed table is provided with the system for scanning of tuft known as

(a) CORRECTACARD CCD

(b) CORRECTAFEED CFD

(c) NEPCONTROL NCT

6. Autolevellers are used for monitoring and regulation of sliver count in

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(a) Carding process

(b) Blowroom process

(c) Drawing process

(d) Roving process

7. The measuring sensor is situated in the feed side before the drafting system.

(a) Open- loop autolevellers

(b) Closed – loop autolevellers

8. The sensing unit is situated in the output side to measure the mass variations of the delivery material.

(a) Open- loop autolevellers

(b) Closed – loop autolevellers

9. The accuracy of the autolevellers shall lie in the range of

(a) ±0.5%

(b) ±0.1%

(c) ±0.4%

(d) ±0.9%

10. This is the tool designed to derive the maximum out of the available resources.

(a) Sliver Eye

(b) Loom Eye

(c) Ring Eye

11. Results are displayed in the form of diagram, spectrogram, VL cures in

(a) Evenness Tester

(b) Ring Eye

(c) Sliver Eye


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1. What is a microprocessor?

2. What are the basic characteristics of microprocessor?

3. What is the use of microprocessor in blending and cleaning?

4. What is the use of CORRECTCARD CCD and NEPCONTROL NCT?

5. What are the types of autolevellers in drawing and write about them.

6. What does a Ring Eye system do in spinning?


1. Write about the applications of microprocessor in textiles.

SENSORS AND ACTUATORS

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Computer exists in a world of digital pulses very different from the analogue world of everyday matters that surrounds us. As long as the two worlds exist apart – computers accepting data through keyboard and mouse and outputting results through monitor and printer – no conflict arises, but when we wish to use computers to monitor and control processes occurring in the real world we find that the two worlds interface extremely poorly. Special hardware, special circuits and special programs are needed to permit computers to make measurements of analogue quantities and even more programs, circuits and hardware is necessary to permit then to control analogue processes.

Sensors are sometimes called as transducers, are devices that can take a physical quantity and convert it to an electrical signal whose voltage is proportional to the value of the parameter being converted .Parameters for which this can be done are called transduceable parameters. Sensors exist that are capable of the conversion of various parameters like force, strain, displacement, temperature etc.,Unfortunately the computers cannot understand an analogue voltage. So the analogue voltage has to be converted to a digital signal – a set of pulses – which is the dynamic equivalent of the pattern of zero’s and one’s stored in the computer’s RAM and which is all the computers really can understand

Strain gauge

The strain gauge is a sensor that converts deformation under load to an electric signal.

The resistance of a section of conductor is given by the formula R = ρ L 0 / A0,

where ρ is the specific resistivity. L0 is the length and A0 is the area of cross section. Now when the conductor is compressed axially it will deform as shown below.

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When the conductor is strained in this manner, the value of L will decrease and that of A will increase as shown in the sketch above. The net effect will be to decrease the resistance of the conductor.Similarly when the conductor is stretched axially it will deform as shown below,

same section under tensile deformation

Deformation exaggerated for clarity

Here L will increase and A will decrease so that the resistance of the conductor will increase. A strain guage consists of a stiff pad to which a long length of wire is fixed, folded back and forth as shown below.

Schematic of a strain gauge

No. of lengths of wire reduced for clarity

The bonding pad is stuck to the object to be strained so that it and the wire fixed to it shares any deformation that might occur. Factors like temperature can also change the resistance of a conductor. Ideally strain gauges should be used in pairs or in bridge circuits so that such effects can be compensated. The constant of conversion from strain to voltage is known as the “gauge Factor”.

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Resistance – Type Transducers

Included in this category of transducers are strain gauges and moving contacts(slide wire variable resistors). A strain gauge measures the external force( pressure) applied to a fine wire. The fine wire is usually arranged in the form of a grid. The pressure change causes a resistance change due to the distortion of the wire. The value of the pressure can be found by measuring the change in resistance of the wire grid. The pressure to resistance relationship is

R= K L/ A

Where

R= Resistance of the wire grid in ohms.

K= Resistivity constant for the particular type of wire grid.

L = Length of the wire

A= Cross sectional area of wire grid.

Strain Gauge Pressure Transducer

Strain Guage

As the wire grid is distorted by elastic deformation, its length is increased, and its cross-sectional area decreases. These changes cause an increase in the resistance of the wire of the strain gauge. This change in resistance is used as the variable resistance in a bridge circuit that provides an electrical signal for indication of pressure.

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Strain gauge Pressure Transducer

Strain Gauge Used in a Bridge Circuit

An increase in pressure at the inlet of the bellows caused the bellows to expand. The expansion of the bellows moves a flexible beam to which a strain gauge has been attached. The movement of the beam causes the resistance of the strain gauge to change.

The temperature compensating gauge compensates for the heat produced by current flowing through the fine wire of the strain gauge.

Strain Gauge Used in a Bridge Circuit

Strain gauges which are nothing more than resistors are used with bridge circuits. Alternating current is provided by an exciter that is used in place of a battery to eliminate the need for a galvanometer. When a change in resistance in the strain gauge causes an unbalanced condition, an error signal enters the amplifier and actuates the balancing motor. The balancing motor moves the slider along the slide wire, restoring the bridge to a balanced condition. The slider’s position is noted on a scale marked in units of pressure.

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Resistance – Type Transducers

Other resistance-type transducers combine a bellows or a bourdon tube with a variable resistor. As pressure changes, the bellows will either expand or contract. This expansion and contraction caused the attached slider to move along the slide wire, increasing or decreasing the resistance and thereby indicating an increase or decrease in pressure.

Bellows Resistance Transducer

Inductance – Type Transducers

The inductance – type transducer consists of three parts: a coil, a movable magnetic core and a pressure sensing element. The element is attached to the core and as pressure varies, the element causes the core to move inside the coil. An AC voltage is applied to the coil and as the core moves, the inductance of the coil changes. The current through the coil will increase as the inductance decreases. For increased sensitivity, the coil can be separated into two coils by utilizing a centre tap,. As the core moves within the coils, the inductance of one coil will increase, while the other will increase.

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Inductance – Type Pressure Transducer

Differential Transformer

Differential Transformer

Another type of inductance transducer utilizes two coils wound on a single tube and is commonly referred to as Differential Transformer. The primary coil is wound around the centre of the tube. The secondary coil is divided with one half wound around each end of the tube. Each end is wound in the opposite direction which caused the voltages induced to oppose one another. A core, positioned by a pressure element is movable within the tube. When the core is in the lower position, the lower half of the secondary coil provides the output.

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Photoelectric sensors

In general, photoelectric sensors are divided into two categories

Reflective type Through beam type

In Relfective type photoelectric sensor, the light beam emitted by the light emitting element is reflected by the target/object and then it is received by the light receiving element. The light emitter and the light sensor are fixed in the same housing. Absent of the target reduces the intensity of light reaching the receiving element and the presence of the target increases the intensity of light reaching the receiving element.

In the case of Through beam type photoelectric sensor, the light emitter and the light sensor are separated out. If the target intercepts the beam it creates a reduction in intensity of light or total absence of light falling on the received. Both types are widely used in industrial applications.

(a) Reflective Type ( b) Through beam Type measurement

The detecting range of a photoelectric sensor is defined as the maximum distance from the transmitter to the receiver that permits the receiver to receive a stable light beam emitted from the transmitter for Through beam type or reflected from the reflector in the case of Reflective type. The speed of operation of the photoelectric sensor is normally specified in the form of response time. The minimum period of time required for the sensor absence of a light beam and output of OFF signal.

Applications

Detection of slots and holes Detection of position of rotary switches and cams Confirmation of proper gripping action of transfer press or robotic arm Detection of small parts like E- ring Detection of component placement (R-L-C components and transistors)

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In Textile industries Photoelectric Sensors are used in Blow Room machines, Yarn Clearer and Loom.

High Precision Laser Beam Photoelectric sensors

Whenever a target is introduced between the Laser beam source and Light sensing element, the output voltage decreases proportionally with the area of the target.

Measurement setup using Laser beam

The beam width varies from 1mm to 30mm. The minimum detectable object size is as low as 0.05mm diameter.

Proximity sensors (Electromagnetic induction type proximity sensor)

A high frequency oscillator used to create a high frequency magnetic field. If ferrous material is brought near the magnetic field the impedance of the sensing coil increases and the oscillation is suppressed. A reflector circuit is used to detect this condition.

Proximity sensors are divided into two categories

Self contained sensors Separate amplifiers sensorsIn the self contained sensors, the sensor head contains the sensing coil and associated

circuit to provide the DC output voltage. It can be used for short distances upto a maximum of 30mm.

In the case of separate amplifier sensors the sensor head contains only the sensing head and the processing circuit is always connected to the head through a coaxial cable. By adding a high gain amplifier the detecting range can be increased to a maximum of 100 mm. They are called as long distance proximity sensors.

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Block diagram of Proximity Sensor

Advantages

1. Non-contact detection2. Long detecting range(10m)3. High speed detection4. Detection of targets of wide range of materials5. Highly reliable6. Quick and automatic calibration

Applications

Ring frames Loom Embroidery unit Fabric processing unit

Displacement Sensors

The principle of operation of inductive gauging sensor is more or less same as that of Electromagnetic induction type proximity sensor. As the target approaches the sensor, the eddy current increases thereby reducing the oscillation amplitude. The oscillating amplitude is converted into change in DC voltage. After processing the output voltage with a linear circuit, the output is made to increase linearly with displacement.

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Displacement measurement using inductive gauging sensor

Laser beam Displacement Sensors

The semiconductor laser displacement sensor consist of a light emitting element and a position sensitive detector. The laser beam is made to fall on the target. The diffused reflection component is then focused on the position of the beam falling on the position sensitive detector. The displacement is then determined by detecting the movement of the beam.

Displacement measurement using Laser beam

Vision system for Position Detection

The target or object pattern is focused on the image pick up element of the camera. The pattern is stored as an electric charge proportional to the brightness of each part of the image. This data is sequentially read from one edge to the other edge and then converted into an image signal./Both interlaced and non-interlaced scanning methods are

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used in vision sustems with the image signal along with the vertical and horizontal synchronisisng signals fed to the image processing system for feature extraction in binary digital conversion the areas brighter than the threshold is called as black. For finding area, position and pattern matching binary digital conversion is widely used. In gray level processing method, the brightness level of each pixel is represented with 8 bits.This is a more versatile system and is used for high accuracy measurement.

Block diagram of Vision system

There are number of special functions incorporated in most of the vision systems. The image captured by the camera is normally divided into 256 levels of gray. By setting a threshold level the image can be converted into black and white regions. The feature will be of immense use in object identification. It is possible to capture the image at a particular instant by means of external triggering facility. Input from an external; photoelectric or proximity sensor cab neb made to trigger the vision system to capture the image at rising edge of the trigger input. In certain vision systems match and mismatch detection modes are also incorporated. In the match detection mode the system count the number of matched pixels and in mismatched mode the system counts the mismatched pixels by comparing the gray – processed image with the reference image. This facility can be used for pattern recognition.

Applications

Fabric inspection Cord web inspection Tack and Loom and Wet Processing Industry.

LVDT (Linear Variable Differential Transformer)

A device which provides accurate position indication throughout the range of value of control rod indication throughout the range of valve or control rod travel is a linear variable differential transformer. LVDT measures linear displacement continuously using magnetic coupling. No physical connection to the extension is required.

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Linear Variable Differential Transformer

The extension valve shaft or control rod is made of a metal suitable for acting as the movable core of a transformer. Moving the extension between the primary and secondary windings of a transformer caused the inductance between the two windings to vary, thereby varying the output voltage proportional to the position of the valve or control rod extension.

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PRACTICE


1. Sensor that converts deformation under load to an electric signal

(a) Differential transformer

(b) Strain gauge sensor

(c) LVDT

(d) Photoelectric sensor

2. This compensates for the heat produced by current flowing through the fine wire of the strain gauge.

(a) Temperature compensating gauge

(b) Resistor

(c) Capacitor

3. This type of sensors consists of a coil, a movable magnetic core and a pressure sensing element.

(a) Resistance –Type Transducers

(b) Inductance – Type Transducers

(c) Strain Gauge Pressure Transducers

4. The light beam emitted by the light emitting element is reflected by the target and then it is received by the light receiving element.

(a) Beam type

(b) Reflective type

(c) Refractive type

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5. The minimum detectable object size is as low as

(a) 0.03 mm diameter

(b) 0.02 mm diameter

(c) 0.07 mm diameter

(d) 0.05 mm diameter

6. In this type of sensors , a high frequency oscillator is used to create a high frequency magnetic field.

(a) Proximity sensors

(b) High precision laser beam type sensors

(c) Displacement sensors

7. This type of sensors consists of a light emitting element and a position sensitive detector.

(a) Proximity sensors

(b) High precision laser beam type sensors

(c) Laser Beam Displacement sensors


1. What is a sensor? What are the different types of sensors?

2. Write about resistance type sensors.

3. What is LVDT?

4. What is a Differential Transformer?

5. What are photoelectric sensors?

6. Write about Vision type sensors?

7. Write the applications of Photoelectric sensors.


1. What is the need for sensors? Write about the different types of Strain gauge sensors used in textile industy.

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2. Write short notes on

(i) Displacement sensors

(ii) Photoelectric sensors

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Computer Application in Textiles-1 vignesh dhanabalan(pavitra)

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Transcript of Computer Application in Textiles-1 vignesh dhanabalan(pavitra)