Mechatronics Introduction and Control Systems

Mechatronics Introduction

• Mechatronics combines mechanical, electronic, controller programming, human-machine interface programming, and information technology.
• It integrates mechanical actuators (hydraulics, pneumatics, motors) with electronic devices (sensors, controllers) using computerized control systems.
• Examples include traffic lights and washing machines.

Control System Types

• Manual: Human operator directly controls the system.
• Automatic: The system uses sensors and actuators to control itself.
• Closed Loop (Automatic): Measures and controls a process, using feedback to adjust the control input.
• Open Loop (Automatic): Measures a process but doesn't use feedback to control it. It only controls the output based on the input.

PID Controllers

• A PID (Proportional-Integral-Derivative) controller is a common feedback mechanism used to continuously adjust a system's output to match a desired setpoint.
• It uses three control parameters:
  • Proportional (P): The output is proportional to the error between the setpoint and the process variable.
  • Integral (I): The controller integrates past errors to eliminate steady-state errors.
  • Derivative (D): The controller anticipates future errors based on the rate of change of the error.

PLC (Programmable Logic Controller) Overview

• A PLC is a digital computer used to control industrial processes.
• They are used for automation and control in various industries.
• They are designed for harsh industrial environments and can handle multiple input/output signals.
• PLCs are essential for automating tasks like controlling motors, valves, conveyor belts, and robotic arms.
• They offer flexibility and programmability, allowing for alterations in operation.

Types of PLCs

• Compact PLC: Usually small and self-contained for smaller industrial applications.
• Modular PLC: Larger, expandable, and more complex, with multiple I/O modules and other components for bigger industrial operations.

Input/Output Devices

• Input devices allow PLCs to receive information from sensors or switches.
• Output devices allow PLCs to control actuators or other devices.
• Examples of input devices include:
  • Push buttons: On/Off switch
  • Limit switches: Detect a specific position or limit.
  • Photo sensors: Detect light intensity.
  • Proximity sensors: Detect the presence of an object.
• Examples of output devices include:
  • Relays: Electromechanical switches used for high-power circuits.
  • Solenoids: Electromagnetic devices used to control valves.
  • Motors: Used to power various mechanisms.
  • Heaters: Used to provide heat to processes.

PLC I/O Signal Types

• Digital Input (DI): Provides On/Off logic signals from input devices like switches and sensors.
• Analog Input (AI): Provides continuous electrical signals representing real-world quantities like pressure, temperature, or level.
• Digital Output (DO): Provides on/off commands to output devices like solenoids and lights.
• Analog Output (AO): Provides continuous electrical signals to control output devices like variable-speed motors and valves.

PLC Programming Overview

• PLCs are programmed with specialized languages like:
  • Ladder logic: Uses graphical representations of electrical relays and contacts. It's popular for its familiarity with electricians.
  • Function block diagram (FBD): Uses graphical blocks to represent functions and connections.
  • Structured text (ST): Uses a structured programming language similar to Pascal or C. It provides a more text-based approach.

HMI (Human Machine Interface) Programming Overview

• An HMI is a user interface that allows human operators to interact with a machine or process.
• It provides a user-friendly display and control for various industrial operations.
• Usually uses a combination of
  • Graphical Elements (buttons, sliders, gauges, charts)
  • Text Displays , to convey information to the operator and allow them to interact with the PLC and the process it controls.

This quiz covers the fundamentals of mechatronics, including the integration of mechanical and electronic systems, different types of control systems, and the functioning of PID controllers. Test your understanding of how these concepts apply to real-world examples such as traffic lights and household appliances.