Automation will be defined because the technology by which a process or procedure is performed without human assistance.
Humans is also present as observers or perhaps participants, but the method itself operates under its own self-direction. Automation is implemented by means of an effect system that executes a program of instructions.
To automate a process, power is required to work the system and to drive the method itself.
THREE COMPONENTS OF AN AUTOMATIC SYSTEM
As indicated above, an automatic system consists of three basic components: (1) power, (2) a program of instructions, and (3) an impression system to hold out the instructions dual-beam laser welding.
The form of power employed in most automated systems is electrical.
The benefits of power include that it (1) is widely available, (2) may be readily converted to other types of power like mechanical, thermal, or hydraulic, (3) are often used at very low power levels for functions like signal processing, communication, data storage, and processing, and (4) may be stored in long-life batteries.
In a manufacturing process, power is required to accomplish the activities related to the actual process.
Samples of these activities include (1) melting a metal in a very casting operation, (2) driving the motions of a cutting implement relative to a workpiece in an exceedingly machining operation, and (3) pressing and sintering parts during a powder metallurgy process.
Power is additionally accustomed accomplish any material handling activities needed within the process, like loading and unloading parts, if these activities aren’t performed manually.
Finally, power is employed to work the system.
The activities in an automatic process are determined by a program of instructions. Within the simplest automated processes, the sole instruction could also be to keep up a specific controlled variable at a specified level, like regulating the temperature during a heat treatment furnace. In additional complex processes, a sequence of activities is required during the work cycle, and therefore the order and details of every activity are defined by the program of instructions.
Each activity involves changes in one or more process parameters, like changing the x-coordinate position of a machine worktable, opening or closing a valve during a fluid flow system, or turning a motor on or off.
Process parameters are inputs to the method.
They’ll be continuous (continuously variable over a given range, like the x-position of a worktable) or discrete (On or Off).
Their values affect the outputs of the method, which are called process variables. Like process parameters, process variables are often continuous or discrete. Examples include the particular position of the machine worktable, the rotational speed of a motor shaft, or whether a visual signal is on or off.
The program of instructions specifies the changes in process parameters and once they should occur during the work cycle, and these changes determine the resulting values of the method variables.
For instance, in computer numerical control, the program of instructions is named part program. The part program specifies the individual sequence of steps required to machine a given part, including worktable and cutter positions, cutting speeds, feeds, and other details of the operation.
In some automated processes, the work cycle program must contain instructions for creating decisions or reacting to unexpected events during the work cycle.
Samples of situations requiring this type of capability include (1) variations in raw materials that need adjusting certain process parameters to compensate,
(2) interactions and communications with humans like responding to requests
for system status information, (3) safety monitoring requirements, and (4) equipment malfunctions.
The program of instructions is executed by an effect system, the third basic component of an automatic system. Two forms of system will be distinguished:
closed loop and open loop. A closed loop, also referred to as a feedback control
system, is one within which the method variable of interest (output of the process) is compared with the corresponding process parameter (input to the process), and any difference between them is employed to drive the output value into agreement with the input.
The process is that the operation or activity being controlled; more specifically, the output variable is being controlled by the system. A sensor is employed to live the output variable and feedback its value to the controller, which compares output with input and makes the specified adjustment to scale back any difference. The adjustment is formed by means of 1 or more actuators, which are hardware devices that physically accomplish the control actions. No measurement of the output variable is
made, so there’s no comparison between output and input in an open loop system.
In effect, the controller relies on the expectation that the actuator will have the intended effect on the output variable. Thus, there’s always a risk in an open-loop system that the actuator won’t function properly or that its actuation won’t have the expected effect on the output. On the opposite hand, the advantage of an open-loop system is that its cost is a smaller amount than a comparable closed loop.
TYPES OF AUTOMATION
Fixed Automation
In fixed automation, the processing or assembly steps and their sequence are fixed by the equipment configuration. The program of instructions is decided by the equipment design and can’t be easily changed. Each step within the sequence usually involves an easy action, like feeding a rotating spindle along a linear trajectory. Although the work cycle consists of straightforward operations, integrating and coordinating the actions may end up within the need for a rather sophisticated system, and computer control is usually required.
Programmable Automation
As its name suggests, the equipment in programmable automation is meant with the aptitude to vary the program of instructions to permit production of various parts or products. New programs will be prepared for brand spanking new parts, and also the equipment can read each program and execute the encoded instructions.
Flexible Automation
Suitability for batch production is mentioned mutually of the features of programmable automation.
The disadvantage of batch production is that lost production time occurs between batches thanks to equipment and/or tooling changeovers that are required to accommodate the following batch.
Thus, programmable automation usually suffers from this disadvantage.
Flexible automation is an extension of programmable automation during which there’s virtually no lost production time for setup changes and/or reprogramming.
