Automation of processes in the company

Automation, a manufacturing system designed to use the ability of machines to perform certain tasks previously performed by humans, and to control the sequence of operations without human intervention. The term automation has also been used to describe non-manufacturing systems in which programmed or automatic devices can operate independently or semi-independently of human control. In communications, aviation and astronautics, devices such as automatic telephone switching equipment, autopilots, and automated guidance and control systems are used to perform various tasks more quickly or better than a human being could.

Automation stages

Automated manufacturing grew out of the intimate relationship between economic forces and technical innovation such as division of labor, energy transfer, and factory mechanization, and the development of transfer machines and feedback systems, as explained below.

The division of labor (that is, the reduction of a manufacturing or service delivery process to its smallest independent phases), developed in the second half of the 18th century, and was first analyzed by the British economist Adam Smith in his book Research on the Nature and Causes of the Wealth of Nations (1776). In manufacturing, the division of labor allowed to increase productivity and reduce the level of specialization of the workers.

Mechanization was the next necessary stage for evolution to automation. The simplification of work allowed by the division of labor also enabled the design and construction of machines that replicated the worker's movements. As energy transfer technology evolved, these specialized machines became motorized, thereby increasing their production efficiency. The development of energy technology also gave rise to the emergence of the factory production system, since all workers and machines had to be located next to the energy source.

The transfer machine is a device used to move the parts that are being worked from one specialized machine tool to another, positioning it appropriately for the next machining operation. Industrial robots, originally designed to perform simple tasks in hazardous environments for workers, are now extremely skilled and are used to move, handle and position light and heavy parts, thus performing all the functions of a transfer machine. In reality, these are several separate machines that are integrated into what at first glance could be considered one.

In the 1920s the automotive industry combined these concepts into an integrated production system. The objective of this assembly line system was to lower prices. Despite the latest developments, this is the production system with which most people associate the term automated.

Feedback

An essential element of all automatic control mechanisms is the feedback principle, which enables the designer to equip a machine with self-correction capability. A feedback loop or cycle is a mechanical, pneumatic, or electronic device that detects a physical quantity such as a temperature, size, or speed, compares it to the established standard, and performs those pre-programmed actions necessary to maintain the measured quantity within limits of the acceptable standard.

The principle of feedback has been used for several centuries. A notable example is the ball regulator invented in 1788 by Scottish engineer James Watt to control the speed of the steam engine. The well-known domestic thermostat is another example of a feedback device.

In manufacturing and production, feedback loops require the determination of acceptable limits for the process to take place; that these physical characteristics are measured and compared with the set of limits, and that the feedback system is capable of correcting the process so that the measured elements meet the standard. By means of the feedback devices, the machines can start, stop, accelerate, slow down, count, inspect, check, compare and measure. These operations typically apply to a wide variety of production operations.

Use in computing

The advent of the computer or computer has greatly facilitated the use of feedback loops in manufacturing processes. In combination, computers and feedback loops have allowed the development of numerically controlled machines (whose movements are controlled by perforated paper or magnetic tapes) and machining centers (machine tools that can perform several different machining operations).

The emergence of the combination of microprocessors and computers has enabled the development of Computer Aided Design and Manufacturing (CAD / CAM) technology. Using these systems, the designer traces the plan of a part and indicates its dimensions with the help of a mouse or a mouse, a stylus or other data entry device. Once the sketch has been determined, the computer automatically generates the instructions that will direct the machining center to make the part.

Another advance that has allowed the use of automation to expand is flexible manufacturing systems (FMS). FMS has brought automation to companies whose low production volumes did not justify full automation. A computer is used to monitor and direct the entire operation of the factory, from the scheduling of each phase of production to the emergence of inventory and tool utilization levels.

Also, apart from manufacturing, automation has greatly influenced other areas of the economy. Small computers are used in systems called word processors, which are becoming the norm in the modern office. This technology combines a small computer with a cathode ray monitor screen, a typewriter keyboard, and a printer. They are used to edit texts, prepare letters, etc. The system is capable of many other tasks that have increased office productivity.

Industrial automation

Industrial Automation (automation; from ancient Greek auto: self-guided) is the use of computerized and electromechanical systems or elements to control machinery and / or industrial processes replacing human operators.

Automation as an engineering discipline is broader than a mere control system, encompassing industrial instrumentation, including field sensors and transmitters, supervisory and control systems, data transmission and collection systems, and applications real-time software to monitor and control plant operations or industrial processes.

The earliest simple machines replaced one form of effort with another that was human-driven, such as lifting a heavy weight with a pulley system or a lever. The machines were later able to substitute natural forms of renewable energy, such as wind, tides, or a flow of water for human energy.

Sailboats replaced rowboats. Later still, some forms of automation were controlled by clockwork or similar devices using some forms of artificial power sources - some spring, a channeled flow of water or steam to produce simple and repetitive actions, such as moving figures, creating music, or games. These devices characterized human figures, were known as automata and possibly date from 300 BC.

In 1801, the patent for an automatic loom using punched cards was given to Joseph Marie Jacquard, who revolutionized the textile industry.

The most visible part of today's automation may be industrial robotics. Some advantages are repeatability, tighter quality control, greater efficiency, integration with business systems, increased productivity and reduced work. Some disadvantages are large capital requirements, a severe decrease in flexibility, and an increase in dependence on maintenance and repair. For example, Japan has had a need to withdraw many of its industrial robots when they found that they were unable to adapt to dramatic changes in production requirements and were unable to justify their high initial costs.

By the mid-20th century, automation had existed for many years on a small scale, using simple mechanisms to automate simple manufacturing tasks. However, the concept only became really practical with the addition (and evolution) of digital computers, whose flexibility allowed to handle any kind of task. Digital computers with the required combination of speed, computing power, price, and size began to appear in the 1960s. Before that time, industrial computers were exclusively analog computers and hybrid computers. Since then digital computers have taken control of most simple, repetitive, semi-specialized and specialized tasks,with some notable exceptions in food production and inspection. As a famous anonymous saying goes, "For many and very changing tasks, it is difficult to replace the human being, who are easily retrained within a wide range of tasks, furthermore, they are produced at low cost by untrained personnel."

There are many jobs where there is no immediate risk of automation. No device has been invented that can compete against the human eye for precision and certainty in many tasks; neither does human hearing. The most useless of human beings can identify and distinguish more essences than any automatic device. The skills for human recognition pattern, language recognition, and language production are beyond any expectation of automation engineers.

Specialized computers are used to read field inputs through sensors and, based on their program, generate outputs to the field through actuators. This leads to control precise actions that allow close control of any industrial process. (It was feared that these devices were vulnerable to the error of the year 2000, with catastrophic consequences, since they are so common within the world of industry).

There are two different types: DCS or Distributed Control System, and PLC or Programmable Logic Controller. The former was formerly oriented to analogous processes, while the latter was used in discrete processes (zeros and ones). Currently both teams are increasingly similar, and either can be used in all kinds of processes.

Human-Machine interfaces (HMI) or Human-Computer interfaces (CHI), formally known as Human-Machine interfaces, are commonly used to communicate with PLCs and other computers, for tasks such as entering and monitoring temperatures or pressures for automatic controls. or response to alarm messages. The service personnel who monitor and control these interfaces are known as station engineers.

Another form of automation involving computers is automation testing, where computers control automated test equipment that is programmed to simulate humans who manually test an application. This is usually accompanied by automated tools to generate special instructions (written as computer programs) that direct the automated test equipment in the exact direction to complete the tests.

Automation and society

Automation has contributed greatly to the increase in free time and real wages of most workers in industrialized countries. It has also increased production and reduced costs, making cars, refrigerators, televisions, telephones and other products available to more people.

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However, not all automation results have been positive. Some observers argue that automation has led to overproduction and waste, which has caused worker alienation and led to unemployment. Of all these issues, the one that has received the most attention is the relationship between automation and unemployment. Certain economists argue that automation has had little or no effect on unemployment. They argue that workers are posted, and not unemployed, and that they are generally hired for other areas within the same company, or on the same job at another company that has not yet been automated.

Others argue that automation generates more jobs than it eliminates. He points out that although some workers may be unemployed, the industry that produces automated machinery generates more jobs than those eliminated. To support this argument, the computer industry is often cited as an example. Company executives often agree that while computers have replaced many workers, the industry itself has created more jobs in computer manufacturing, sales, and maintenance than the device has eliminated.

On the other hand, there are union leaders and economists who affirm that automation generates unemployment and that, if it is not controlled, it will lead to the creation of a vast army of unemployed people. They maintain that the growth in jobs generated by the public administration and in the service sectors has absorbed those who have become unemployed as a result of automation, and that as for these sectors, government programs will be saturated or reduced, it will be known the real relationship between automation and unemployment.

Automation levels

The concept of automated systems can be applied at different levels of factory operations. We normally associate the concept of automation with the production of individual machines. However, the production of machines by itself is created by subsystems that by themselves can be automated.

We can identify five possible levels of automation in a production plant and they are explained with the following figure

Process automation

Basic elements of an automated system

Energy: to complete the process and operate the system Program: to direct the process Control system: to execute the instructions

Process automation

Energy to carry out automated processes

An automated system is used to operate some processes. The energy is needed to drive the process as well as the controllers.

Types of energy

Electrical, Mechanical, Thermal

Alternative sources: fossil fuels, hydro, solar, wind.

Energy for the process

In production, the term process refers to the manufacturing operations that are carried out on the workpiece.

Energy is also required for material handling functions. Loading and unloading of materials. Transportation of material between workstations.

Process automation

Automation power

Power is required for the following functions.

Control Unit - Modern controllers use electrical power to read program instructions, perform control calculations, and execute instructions by transmitting commands to actuator devices.

Power to activate the control signals: the commands sent by the control unit are carried out by electromechanical devices called actuators. Commands are commonly transmitted through low voltage control signals.

Information collection and processing: the system information must be collected and used as input data in the control algorithms. In addition, it may be necessary to keep track of process performance or product quality. These functions require energy, albeit in modest amounts.

Program

Duty cycle programs

The steps of the process to manufacture a part are carried out during a work cycle. That is, in each work cycle, a part is produced (although in some operations more than one is produced). These steps are specified in a duty cycle schedule.

Process parameters: these are process inputs such as the temperature of an oven, or a coordinate in a positioning system.

Process variables: these are process outputs such as the actual oven temperature or the current position in the coordinate system.

Decision making in the programmed work cycle

Operator interaction: Although the instruction program is intended to function without human interaction, the control unit may require input data provided by the operator to function.

Different parts or product styles: An automated system can be programmed to perform different work cycles on different parts or product styles.

Variations in work start units: In many manufacturing operations, initial work pieces are not consistent, so additional steps may be necessary.

Control systems

The control system of an automated system allows the program to be executed and the process to perform its defined function. Control systems can be of two types:

Closed cycle control systems Open cycle control systems.

Closed cycle

In a closed loop control system the output variable is compared to an input parameter, and any difference between the two is used to make the output match the input.

Process automation

Open Cycle

An open loop control system operates without the feedback loop, without measuring the output variable, so there is no comparison between the actual value of the output and the desired value in the input parameter.

Process automation

Advanced Automation Features

Functions that concern the improvement of the performance and safety of the equipment, such as:

Security monitoring, maintenance and repair diagnosis, error detection and fault recovery.

Security monitoring

Security system responses:

Stopping the system. Turning on audible alarms. Reducing the speed of processes. Taking actions to correct the security violation.

Sensor types:

Limit Photoelectric Temperature Smoke Pressure Vision

Maintenance and repair diagnosis

Ability of an automated system to assist in identifying potential or current sources of malfunction or failure.

Status monitoring Failure diagnosis Recommendations for repair procedure

Use of computerized control in a system to automate the taking of necessary corrective actions to restore normal operation after the failure has occurred.

Steps:

Error detection. Error recovery.

Error detection

Using the sensors available in the automated system to determine when a deviation or malfunction has occurred, correctly interpret the sensor signals, and classify the error.

Classification of the error:

Random errors Systematic errors Aberrations

Steps for detecting errors in an integrated manufacturing cell: Categories of errors and possible malfunctions they cause

Process automation

Error recovery

Applying the necessary corrective actions to overcome the error and return the system to normal operation.

Strategies:

Make adjustments at the end of the current work cycle Make adjustments during the current cycle Stop the process to apply corrective actions Stop the process and ask for help

Bug fixes in an Integrated Manufacturing Cell; Possible corrective actions that should be taken in response to errors detected during the operation