Control Systems, Automation, and Robotics
Control Systems
A control system is a set of devices within a machine designed to manage and regulate the behavior of a specific variable. For a machine to operate automatically, a control system is essential.
Open Loop Control Systems
These systems operate for a predetermined time, irrespective of environmental changes. They function based on a preset value, known as the setpoint. Examples include dishwashers, washing machines, and basic radiators.
Schematic: Input Devices – Control Devices – Output Devices
Closed Loop Control Systems
These systems can modify their activity based on environmental variables. They utilize a feedback process, continuously capturing the value of the controlled variable. The controller adjusts its actions accordingly. Examples include refrigerators and electric radiators with thermostats.
Schematic: Input Device – Control Device – Output Device – Feedback – Input Device
Structure of a Control System
- Sensor: Detects variations in a physical quantity and converts them into signals usable by the control system.
- Controller: Receives sensor information, processes it, and determines the necessary action.
- Actuator: Transforms the controller’s commands into physical actions that affect the system.
Automation
An automation is a component of a machine or system capable of executing one or more actions without manual intervention. It can also be defined as a system that consistently repeats the actions it was designed for.
Mechanisms and Components
Gears
A gear mechanism is formed by the combination of gears or other mechanical operators. The teeth of the gears are in direct contact, ensuring uniform size. Their orientation, tooth shape, and connection module are key to their classification. An example is the hands of a clock.
Relays and Elements
A relay is an electromagnetic operator that opens, closes, or switches one or more circuits based on the position of its contacts. Relays consist of:
- Electromagnet: Composed of a magnetic core and coil.
- Mobile Element: Includes a plate, pivot, rod, and damping system.
- Contacts: Elements subjected to mechanical stress by electric current. They can act as switches (single contact) or commutators (two contacts).
Robots
A robot is an electronic device capable of automatically executing various operations or movements. It is a reprogrammable automation, meaning the instructions within the controller (known as the program) can be modified at any time.
Robot Sensors
- External Sensors: Capture environmental variables such as light and pressure.
- Internal Sensors: Control the robot’s displacement mechanisms.
Possible Exercises
Analyze the following automation examples:
- Traffic Light: Time-based (traffic), open loop.
- Answering Machine: Collects calls, open loop.
- Ticket Dispenser: Number of parked cars, closed loop.