Industrial Automation T Rajendran

Industrial Automation  Control Systems  Process Control  Industrial Control  Computer Integrated Manufacturing  Systems Modeling  Systems Engineering  Real Time Programming  Software tools

Expectation of Automation  High Reliability  Fast Trouble shooting  Simple Operation  Easily Configurable  High Accuracy  Optimization functions and processing of operating data  Flexibility

Process Controls PC IS Integrated Control & Management systems … MIS

History  Pioneering period – 60 – Electronic devices  Direct Digital control  Microcomputer  Computer controlled Process plants –Centralized –Distributed –Process Models –Advanced Control (AI)

Process Controls

Process Control Control Signal generation Steam out Water in Water out Temp sensor- + Set point (desired value) Deviation (error) Steam in

Basic principles of controller loop  Memory - Set Point  Comparator for set point (measured value MV) as reported by transmitter  Deviation = error  Amplifier – amplifies the control deviations – output of the controller

Process Control  Open Loop Control  Closed Loop control

Process Control  Two position control  Multi position control  PID Proportional control (proportional, integral or derivative)  Ratio control  Cascade control

Controller Operation controller - Set point error Control signal Control element sensor process Measured value Auto/manual

Position control High set point Low set point

Control actions No control Proportional only PI PID Set point Time Control value

Instrumentation

Instrumentation  Pressure  Flow  liquid level  Temperature  Pneumatic and control valves

Transducers  Sensors  high / low limits of measurand

Transducers  To measure / sense  to convert measured value to a useful output

Transducers  Measurement –Type of measurand – Number of measurements – Sensing measurement – Transduction element – Range of measurement  Conversion –Specific format –Amplified –Conversion of AC to DC

Transducers  Conventional  Silicon  Fiber Optic

Transducers  Conventional  Silicon  Fiber Optic  Displacement / motion transducers  Temperature Transducers  Pressure Transducers  Liquid level Transducers  Liquid Flow

Intelligent Sensors  On-chip signal processing  MEMS (Micro Electro Mechanical Systems) sensors  BIOSENSORS  NANOSENSORS

NANOSENSORS & future trends  1 nm = 1 millionth of a mm

Building Blocks in Automation

Building blocks  The Processor  Analog & Digital I/O modules  interrupts, Timers/counters  Display controls  SCADA (Supervisory control and data acquisition systems)

Processing System  The use of Microprocessors (calculator chips & Mini computers)  Architecture –Input, Memory, Output, MicrpP Address bus, Data bus, control bus Address bus, Data bus, control bus  8, 16, 32, 64 bits  Microprocessors & microcontrollers

Analog & Digital I/O modules  Basic signals Analog inputs Digital inputs Interrupt inputs Timer / counter inputs Control outputs Display outputs

Analog & Digital I/O modules  Basic signals Analog inputs Digital inputs Interrupt inputs Timer / counter inputs Control outputs Display outputs

Inside look of a real time sysytem Processor & memory module Analog inputs Digital inputs Interrupt inputs Timer / counter inputs Control outputs Display outputs Interrupt controller Timer / counter Analog input module

I/O modules  Analog input –From Sensors –Measurand like flow, position, temperature … –Signal may be amplified, filtered or/and isolated  Digital input –Refer to ON-OFF status of valves, linit switches.. (1 bit )

I/O modules  Interrupt input –Draw attention of real time system towards abnormal situations –Attends to interrupt and resumes normal work  Timer / Counter –Clock input or Gate input to enable/ disable timer/counters –Output of timer/counter can be used as interrupts

I/O signals  Display output signals –LED, LCD, VDU, alarms –Status of process, limits sets –May control or operator assisted  Control output signal –Required to drive the control valves, motors etc –May be simple ON/OFF or fine control of motor speed, position, displacement, flow.. –Analog signals / digital actuators

Analog input  The module continuously scans the analog input signals in the pre defined order and frequency  Amplifies -> converts to digital -> processor and memory module for processing  EPROM or switches  Local intelligence

Digital Input  Directly accepted by processor  N bits in parallel  Local intelligence

Analog Output  Digital multiplexer  Digital to Analog converter  Master processor executes two I/O instructions –Write Data byte/word in digital output port –Write address byte/word in address port

Interrupt control  Interface between no. of interrupting devices and master processor  Priorities allocation- static or dynamic.

Timer / Counter  Number of timers and counters which may be cascaded or used independently  Count in the form of data byte/word  Clock from the processor or external

Display Control module  Manual entry sub module  CRT controller sub module  LED / LCD control sub module  Alarm annunciator sub module  Printer controller sub module

SCADA  Supervisory Control And Data Acquisition Systems –Channel scanning –Conversion into engineering units –Data processing

CAD / CAM / CIM

CIM cim Process planning draf ting MeM fe CNC Robots Sche dudle Prod plan cad Tool design fms simul ation ERP Shop floor data

CAD / CAM / CIM  CIM, Concurrent Engineering  Product Life Cycle Management  Engineering Modeling  CIM databases  Computer aided process planning  IT & ERP  Manufacturing automation – PLC, CNC, Robots

CAD/CAM/CIM  Flexible Manufacturing  Shop Floor Data Collection  Simulation

Concurrent Engineering  DESIGN software –Solid Modeling –Assembly modeling –Sheet metal design –Drafting –Tolerance analysis –Mechanism Design –Mould Design –Thermal Analysis –Piping Design –Optimization –Tool Design

Concurrent Engineering  Process Planning  ERP  Shop Floor Data Collection  PLM  EDM

Concurrent Engineering  Visualization / Simulation –Factory simulation –Rapid prototyping –Plastic injection moulding –Forming –Forging –Casting