ESE61 ESE6 16 - Indus Industrial trial Aut Automatio omation n and Robotics Chapter 1 Introduction Introducti on to Automation Automation
Definition
Automation - greek word greek word „Auto‟ (self), „Matos‟ (moving) The technique, method, or system of operating or controlling a process by highly automatic means, as by elec electtron ronic devi device ces, s, redu reduci cing ng hum human inte interv rven enti tion on to a minimum.
In ind indust ustrial rial con contex text, auto autom matio ation n can can be defin efined ed as a technology that is concerned with the use of mechanical, electrical/electronic, electrical/electronic, and computer-based systems to control production process.
Example Manual PCB Insertion :
Example Automatic PCB Insertion :
History of Automation
Automation has been introduced very early in the history of human civilization, in the form of mechanization of tasks with mechanical tools such as wheel, lever and pulley, which amplify the physical capabilities of human and animal. Mostly applied for construction, agriculture and textile.
History of Automation
Later, natural power sources such as water, wind, and gravity were utilized to power up machines, namely the water wheel and windmill that can run without any involvement of human or animal strength.
History of Automation
Thomas Newcomen invented the first commercially successful steam engine in 1712, to pump water out of coal mines, but not very efficient and wasted a lot of fuel. Later in 1770s, James Watt made significant improvements to the steam engine and became much more efficient that helped stepped-up the pace of the industrial revolution (1780s).
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Industrial revolution accelerated automation. Later, Michael Faraday, 1831 design the electric motors and Barsanti and Matteucci, 1854 introduced internal combustion engines. Manufacturing became more productive with these new automated machines.
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Triode (vacuum tube) was invented in 1906, as the key component for radio, telephone, radar, and television. It is also helped in development of early computer systems. Transistor (invented in 1947) had replaced triode as the main electronic device, less power and a lot more smaller in size.
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Integrated circuits (invented in 1958), combines large number of tiny transistors into a small chip, that consequently increased electronic circuit performance and reduced cost enormously.
Technology of IC has laid the path for the introduction of the first microprocessor (Intel 4004, in 1971), which integrates all the functions of a central processing unit (CPU) of a computer.
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The new technologies have allowed the introduction of advance automatic control systems, with complicated control functions and faster execution of calculations. In general, automation has becomes part of our life. Throughout the history, automation has changed the way we are doing our work.
Purpose of Automation System
Improvement of Quality Quality of work/service Quality of product
Improvement of Quantity Quantity of work/service
Quantity of product
Application and Implementation
Automation system can be found everywhere……..???? Banking system
-Auto teller Machine, cash deposit etc.. -Internet banking Retailing
Fast food outlets – Ordering and payment Food serving – robot, conveyor system Online shopping – ordering and payment Tourism
Hotel booking, flight booking, car rental etc… Transportation
- Auto cruise system - Navigation system
Application and Implementation Traffic control
-Air traffic -Ground traffic – Traffic light, AES etc.. Home automation
- Electrical appliances - Smart home Military
- Radar system - Missile control - UAV, UUV Agriculture
- Plant irrigation - Animal feeder - Fruit plucking Industrial automation
- Raw material /unfinished product to finished product
Automation System
Element of Automation System Automation System consist of three basic elements: Power to accomplish the process and operate the system, a program of instruction to direct the process, and a control system to actuate the instruction
Power
Program of Instruction
Control System
Process
Automation System
Power Element An automated system is used to operate some process, and power is required to drive the process as well as the controls.
Main power source is electrical where it can be obtained with reasonable cost.
The electrical power also is readily converted to alternative power energy such as mechanical, thermal, light, acoustic, hydraulic and pneumatic.
Can be used to power up low power equipments, e.g computer, data transmission system..etc.
Easy to store and available at any locations (long-life batteries).
Automation System
Power for the process
Process in automation system refers to manufacturing operation.
The power form that is applied directly to the process normally converted from electrical form.
Example of action in the process that required power
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Loading and unloading the product,
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Product transport between operations
Example: Automated bottle making process
Automation System
Power for Automation
Other than the basic power requirements for the process.
Use to power up the sensors, control unit, actuate the control signals, data acquisition and processing.
Automation System
Program of Instruction The action performed by automated process are defined by a program of instructions. Each part or product made in the operation requires one or more processing steps that are unique to that particular part or product. The particular processing steps for the work cycle are specified in a work cycle program. The work cycle can be a single process or combination of multiple process.
Automation System
Program of Instruction Example (process), Consider an automated turning operation in which a cone-shaped geometry is generated. Assume the system is automated and that a robot is used to load and unload the work unit. The work cycle consists of the following steps: (1) Load starting workpiece, (2) position cutting tool prior to turning, (3) turn, (4) reposition tool to a safe location at end of turning, and (5) unload finished workpiece. Identify the activity (ies) and process parameter(s) in each step of the operation.
Automation System
Program of Instruction Example (Solution), Step (1): The robot manipulator reaching for the raw workpart, lifting and positioning the part into the chuck jaws of the lathe, then removing the manipulator to a safe position to await unloading. The process parameters are the axis values of the robot manipulator (which is change continuously), the gripper value (open or close), and the chuck jaw value (open or close). Step (2): Movement of the cutting tool to a “ready” position. The process parameters are the xand z- axis position of the tool. Step (3) Requires the simultaneous control of three process parameters: rotational speed of the workpiece (rev/min), feed (mm/rev), radial distance of the cutting tool from the axis of rotation. To cut the conical shape, radial distance must be changed continuously at a constant rate for each revolution of the workpiece. For a consistent finish on the surface, the rotation speed must be continuously adjusted to maintain a constant surface speed (m/min); and for equal feed marks in the surface, the feed must be set at a constant value. Depending on the angle of the cone, multiple turning passes may be required to gradually generate the desired contour. Each pass represents an additional step in the sequence. Step (4) & (5) involve the reverse activities as steps (2) and (1), respectively, and the process parameters are the same.
Automation System
Program of Instruction At the early version of operations, the work cycles were controlled by hardware components, such as limit switches, timers, cams, and electromechanical relays. There are advantages using these hardware components:
(1) Required considerable time to design and fabricate, thus forcing the production equipment to be used for batch production only (2) Making even minor changes in the program was difficult and time consuming; and (3) the program was in a physical form that is not readily compatible with computer data processing and communication.
Automation System
Program of Instruction Modern controllers used in automated systems are based on digital computers. The programs for computer controlled equipment are contained in magnetic tape, diskettes, compact disks (CD-ROMs), computer memory and other modern storage devices. Thus, the work cycle may include manual steps, where the operator performs certain activities and the automated system performs the rest.
Automation System
Program of Instruction Decision making in the Programmed Work Cycle Many automated manufacturing operations require decisions to be made during the programmed work cycle to cope with variations in the cycle. In many cases, the variations are routine elements of the cycle that include:
Operator interaction.
Different part or product styles processed by the system.
Variation in the starting work unit. The program can be designed to respond to sensor or operator inputs by executing the appropriate subroutine corresponding to the input. In other cases, the variations in the work cycle are nor routine at all such as failure of an equipment. Thus, the program must include contingency procedures or modifications in the sequence to cope with conditions that lie outside the normal routine.
Automation System
Control System The control element of the automated system executes the program instructions. The control system causes the process to accomplish its defined function, which for our purpose is to carry out some manufacturing operation. The controls can be either closed loop or open loop. A closed loop control system, also known as a feedback control system, is one in which the output variable is compared with an input parameter, and any difference between the two is used to drive the output into agreement with the input.
input
Controller
Actuator
Feedback Closed loop control system
Process
Output
Automation System
Control System Open loop control system operates without the feedback loop, so no comparison is made between the actual value of the output variable and the desired input parameter. The controller relies on an accurate model of the effect of its actuator on the process variable.
input
Controller
Actuator Open loop control system
Process
Output
Automation System
Control System Example
A (one axis) positioning system consisting of a lead screw driven by a dc servo
A (one axis) positioning system consisting of a lead screw driven by a stepper motor
Advantages and Disadvantages
Reason for automating Increase labor productivity
Reduce labor cost Mitigate the effects of labor shortages
Reduce or eliminate routine manual and clerical tasks
Improve worker safety Improve product quality Reduce manufacturing lead time Accomplish processes that cannot be done manually Reduce unit cost
Source: encyclopedia britanica
Advantages and Disadvantages
Reason for not automating Task is too technologically difficult to automate
Short product life cycle Customized product – one-of-a-kind
Flexibility in coping with changing demand
Source: encyclopedia britanica
