A1.3.7 Control Systems in Real-World Applications (HL only) Notes

Understanding Control Systems

These systems are integral to modern technology, automating tasks and ensuring efficiency, safety, and precision.

Key Components of Control Systems

1. Sensors: Detect and measure physical quantities (e.g., temperature, pressure) and convert them into signals.
2. Controllers: Process input data and make decisions based on predefined algorithms.
3. Actuators: Execute actions based on controller signals, such as opening a valve or moving a motor.
4. Feedback: Provides information about the system's output to adjust future actions.

The Input-Process-Output Model

1. Input: Data or signals received by the system (e.g., sensor readings).
2. Process: The manipulation of input data by the controller to make decisions.
3. Output: The actions taken by actuators based on the controller's decisions.
4. Feedback: Information about the output used to adjust the system's behavior.

Autonomous Vehicles

Autonomous vehicles are complex control systems that rely on a sophisticated interplay of sensors, algorithms, and actuators.

1. Sensors:
   1. LIDAR: Provides 3D mapping and object detection.
   2. Radar: Detects objects in poor weather conditions.
   3. Cameras: Perform visual recognition tasks.
   4. Ultrasonic Sensors: Measure close-range proximity.
   5. Inertial Measurement Units (IMUs): Track the vehicle's motion.
2. Control Algorithms:
   1. Path Planning: Calculates optimal routes.
   2. Obstacle Avoidance: Predicts and avoids collisions.
   3. Decision-Making: Interprets traffic situations using AI.
3. Actuators:
   1. Steering Systems: Control the vehicle's direction.
   2. Throttle Control: Regulate speed.
   3. Braking Systems: Ensure safe stopping.

Home Thermostats

Home thermostats regulate temperature using a simple yet effective control system.

1. Sensors: Measure the current room temperature.
2. Controller: Compares the current temperature to the desired setpoint.
3. Actuators: Activate the heating or cooling system based on the controller's decisions.
4. Feedback: Continuously monitors the temperature to maintain comfort.

Automatic Elevator Control Systems

Automatic elevator control systems optimize elevator operations to minimize wait and travel times.

1. Sensors: Monitor the current position of elevators and passenger requests.
2. Controller: Uses algorithms to assign elevators efficiently.
3. Actuators: Control motors to move elevators between floors.

Automatic Washing Machines

Automatic washing machines use control systems to automate the laundry process.

1. Sensors: Detect load size, water level, and water turbidity.
2. Controller: Determines optimal cycle settings using algorithms like fuzzy logic.
3. Actuators: Control water inlet valves, drain valves, and motors for agitation and spinning.

Traffic Signal Control Systems

Traffic signal control systems manage traffic flow to reduce congestion and improve safety.

1. Sensors:
   1. Inductive Loop Detectors: Sense vehicle presence.
   2. Cameras: Monitor traffic and pedestrian activity.
   3. Pressure Pads: Detect pedestrians at crosswalks.
2. Controller: Processes sensor data to optimize signal timing.
3. Actuators: Control traffic lights and pedestrian signals.

Irrigation Control Systems

Irrigation control systems optimize water usage in agriculture.

1. Sensors: Measure soil moisture and weather conditions.
2. Controller: Uses data to schedule irrigation cycles.
3. Actuators: Open and close valves to deliver water precisely.

Home Security Systems

Home security systems protect against intrusions and hazards using a network of sensors and actuators.

1. Sensors:
   1. Motion Detectors: Use infrared technology to detect movement.
   2. Door and Window Contacts: Sense openings.
   3. Environmental Sensors: Monitor smoke, heat, and carbon monoxide.
2. Controller: Analyzes sensor data to identify threats.
3. Actuators: Trigger alarms, lock doors, and send notifications.

Automatic Doors

Automatic doors use control systems to enhance convenience and energy efficiency.

1. Sensors: Detect approaching individuals using motion or optical technology.
2. Controller: Processes sensor data to determine when to open or close the door.
3. Actuators: Operate motors or hydraulic systems to move the door.