Automation and Control Systems Overview

Automation and Control

• Automation is the process of transforming a mechanism, device, machine, facility, or process to run automatically.
• Automatic control uses control systems to run equipment like machinery, factory processes, boilers, and ovens.
• Control systems also manage switching in telephone networks, steering and stabilizing ships and aircraft.
• Some processes are completely automated with minimal human intervention.

Programmable Logic Controller (PLC)

• Before PLCs, relays performed logic operations. Ladder logic, a schematic drawing technique, was used.
• Ladder logic formed a basis for PLC programming languages.
• PLCs are a significant advancement in industrial automation, used in numerous applications.
• Programmable logic controllers became commercially available in the late 1960s.

PLC (Types)

• Compact PLCs are smaller and self-contained.
• Modular PLCs allow more flexibility and can increase functionality.

PLC (Examples)

• Different manufacturers offer various PLC models. Examples include Allen-Bradley ControlLogix, Siemens S7-300, Modicon Premium, Mitsubishi iQ, Koyo DL405, and Omron CJ1, GE RX3I, and Honeywell.

Supervisory Control and Data Acquisition (SCADA)

• SCADA systems oversee and collect data from processes, using Human-Machine Interfaces (HMIs) to show data and provide controls.
• PLCs are often used within SCADA systems to collect and control processes.
• SCADA systems collect data, transfer it, show it to a user and manage control operations.

SCADA (components)

• SCADA systems utilize components such as programmable logic controllers (PLCs) and Human-Machine Interfaces (HMIs).
• Connections between components often use different communication buses like, a Plant bus and Field Bus.
• The components allow a process to be monitored and controlled by an operator.

SCADA (How it works)

• Data collection involves gathering information from interconnected devices.
• Data transfer moves collected data through different networks.
• Data display allows the user to observe the transferred data.
• Control and operation enable user interaction and control on the monitored process.

SCADA (levels)

• The levels involved in SCADA systems include:
• SCADA level
• Operator
• Engineering
• Plant Bus
• Plant Level
• Field bus
• Field level
• Sensor/Actuator Bus
• Sensor/direct I/O

programmable logic controller (PLC) Objectives

• PLCs add value to raw materials by producing higher value products (either finished or intermediate products).
• Machines require human intervention in tasks such as monitoring, loading/unloading, inspecting, participation in the production process, and maintenance.

programmable logic controller (PLC) Gains with Automation

• Automation reduces labor and material costs.
• Automation decreases hazardous work and improves safety.
• Automation improves product quality.
• Automation increases productivity and quality in job creation.

Programmable Logic Controller (PLC) Ladder Logic

• Before PLC technology, electromagnetic relays designed automation systems.
• Ladder logic diagrams utilize relays and are a precursor to PLC programming.
• Ladder logic is based on relay circuitry to connect electrical components.

Electromagnetic Relay

• Joseph Henry created the first relay in 1836.
• A relay uses a magnet and switches to turn circuits on and off.
• The coil is energized to attract an armature through a magnetic field, closing/opening contacts.

Hardware vs. Software

• Hardwired systems use interconnected physical components like relays, electronic boards, etc, to develop logic and perform operations.
• Hardwired systems can be very reliable but are typically inflexible to modify or adapt in the long-term.
• Software systems use programming to implement functions, making them adaptable and flexible to changes but often have lower reliability.

Type of Protection

• Single protection: Using components/functions, or periodic checks to ensure safety.
• Single with supervision: Self-monitoring to ensure stability and function.
• Redundant protection: Duplicate crucial components or systems to ensure they continue functioning, even if one component stops working.
• Redundant with supervision: Redundant systems require continuous monitoring of different components and systems, to ensure stability.

Types of Systems

• Static systems don't change over time.
• Dynamic systems change with time.

Models

• Black box models use simple inputs, and outputs to define the system without understanding the internal mechanisms.
• White box models fully define the system including input, and outputs, as well as internal mechanisms.

Examples

• Spring-mass-damper system involves a differential equation to describe the response of the system.
• RLC circuits use a similar differential equation (or integro-differential equation) to predict the circuit's behavior, often in a sinusoidal fashion.

Applications

• Modern control systems apply to various areas, including vehicle steering, automated aircraft control systems, and precision control of machinery.

Explore the fundamentals of automation and control systems in this quiz. Learn about the evolution from relays to programmable logic controllers (PLCs) and the types and examples of PLCs used in industrial automation. Test your knowledge on how these systems function to enhance efficiency with minimal human intervention.