An Overview on Industrial Automation – Need, Structure, Types & Technologies

To resolve the automation and control issues, industries use the ever-changing technologies in control systems for efficient production or manufacturing processes. These requires the high quality and reliable control systems. New trends in industrial automation deals with latest control devices and communication protocols to control  field devices like control valves and other final control elements. Some of the smart devices or instruments used in automated industry has the ability to control the processes and also communication capabilities without interfacing to other field  level control devices like PLC’s.

What is Industrial Automation?

Industrial automation is the use of various control devices like PC’s/PLC’s/DCS, used to have control on various operations of an industry without significant intervention from humans and to provide automatic control performance. In industries,  control strategies use a set of technologies which are  implemented to get the  desired performance or output, making the automation system most essential for industries.

Industrial automation involves usage of advanced control strategies like cascade controls, modern control hardware devices as PLC’s,sensors and other instruments for sensing the control variables, signal conditioning equipments to connect the signals to the control devices, drives and other significant final control devices, standalone computing systems, communication systems, alarming and HMI (Human Machine Interface) systems.

Need of Automated Industry

• To reduce Periodic or Manual checking

In some critical applications periodic checking of the process variable is necessary to perform  industrial operations. Automation equipment reduces the periodic or manual operations and establishes the automatic working conditions.

• To increase the Productivity

Automating the manufacturing and other production processes increases the production rate by producing output at greater amounts for a given labour input

• Reduce the Production Cost

Using the automatic machines and equipments, human intervention to control the processes abruptly falls. This reduces the investment on the labor cost hence the production cost.

• To improve Product Quality

Continuously doing the same work may not be perfect in all the cases in terms of quality specifications with human efforts. With automation equipment ,one can get reliable and uniform product quality by using  real time hardware control devices.

• To increase the Flexibility

Using the automation equipment various , process are handled simply without getting any complex environment particularly in manufacturing processes.

• Operator Friendly and Improves the Safety

Complexity of operating the equipments or processes is reduced with  industrial automation. It changes the position of the operator as operator to the supervisory role.

Structure of Industrial Automation

Structure of the industrial automation explains various levels of operation.These include  sensor level, automation control level (Unit, cell, process controls),supervision level and enterprise level.Pyramid structure indicates that, as you go up the tip , the information is aggregated and while coming down it is dissolved. This means we will get the detailed information for a particular variable at the bottom. Industrial automation doesn’t mean that all the levels are automated like enterprise level need not be automated.

Sensor level is also called as process layer. It uses the sensors and actuators to get the values of the process variables in continuous or periodical manner. These act as eyes and arms of the industrial processes. Some of these instruments includepneumatic instruments, smart instruments, etc.

Automation control level or control layer uses industrial control devices like PC’s/PLC’s/DCS, etc. This level utilizes the various embedded processors, PID algorithms to control the process.

Supervising level or SCADA layer gets lots of channel information and stores the data in the system database. It acquires data from various control devices and displays them on HMI’s (Human Machine Interface). It also gives alarm to indicate the levels of the process and control variables. It uses special software to get the data and communication protocols to interact with the field devices.

Enterprise level performs the tasks like scheduling, orders and sales, product planning, etc.

Types of Industrial Automations

Automation systems are classified into four basic types ,based on the flexibility and level of integration in manufacturing processes. Those are described below.

1. Fixed Automation

In this sequence of operations to be performed are fixed by the equipment configuration. It is used in high volume production with dedicated equipment. Examples of this automation system are automated assembly lines, distilled process, machine transfer lines.

2. Programmable Automation

In this, sequence of operations can be changed by changing the program. Sequence of operations is varied based on the different product configurations. Also new programs can be entered into the programmable devices for the new products. This type of system is used in batch processes, steel rolling mills, industrial robots, etc.

3. Flexible Automation

It is the extension for the programmable automation. This offers a greater flexibility to deal with product design variations. Operators can give commands in the form of codes in the computer program if wants to change the sequence of the process. Lower level equipments receive the instructions to operate at the field level without losing the production time. This type of automation is used in manufacturing multipurpose CNC machines, automatic guided vehicles, etc.

4. Integrated Automation

In this type total system is fully automated under computer control. Starting from designing process to the dispatching, whole system is completely automated. Even the equipment is handled by the robots. This system is used in computer integrated manufacturing systems.

Automation Equipments

• Sensors and Actuators

A sensor senses the various process variables and converts them into the electrical or optical signals. These sensors include temperature, pressure, velocity, flow, etc.

Actuators convert the electrical signals to the mechanical means to gain control over processes. These include relays, magnets, servomotors, etc.

Some of the sensors and actuators have the capability to communicate with the industrial field communication buses which comes under the smart devices.

• Industrial computers

Programmable Logic controllers (PLC’s) also called as industrial computers are capable of being programmed to perform certain control functions. It consists of a CPU or processor, I/O modules (both analog and digital) to connect the various input/output devices and relay modules. These may be modular which is of fixed typeor integrated types to extend modules based on the inputs available.

Along with the PLC’s, conventional PC’s are used to control the process by online or by changing the programs. PLC’s comes with dedicated software to program the control strategy.

• HMI(Human Machine Interface)

HMI’s offers the facilities like, displaying the information on computer screens and other displays, logging the results in the database, giving alarm signal, etc. It uses technologies like SCADA (Supervisory Control and Data Acquisition) and other visual based technologies.

• Communication system
  

In industries many sensors, actuators, controlling PC’s and other control devices are geographically distributed and interacting with each other via several data buses. There are three types of buses used in the industrial automation i.e., factory bus, process bus, and the field bus.

Field bus interacts between field instruments and the control devices while the process bus connects the supervising level computers to the control devices like PLC’s. Factory bus connects the higher level of the organization to the supervising level. Different protocols are used for the communications like RS-485, profibus, CAN control modbus,etc.

Thank you for spending your valuable time with this article and hope that you have understood what industrial automation is. Here is a question for you regarding automation,

What is artificial Intelligence?

Answer: Please leave your answers in the below comments section.

Photo Credit:

• Automated process in industries by wikipedia, cardinalintegrated
• Manual control by opticontrols
• Automation Structure by synapticon
• Automation Layers by inetlb
• Fixed Automation by lincolnelectric
• Programmable Automation by precesionautomationinc
• Flexible Automation by rtcmagazine
• Equipments of Automated Industry by smaruk