A feedback control system is a type of control system that uses feedback from the output to regulate and maintain the desired state of a system. The main components of a feedback control system are as follows:
Plant/Process: This is the system or process that is being controlled. It could be a physical system like a robot arm, a temperature control system, or even a financial market. The plant is the part of the system that is influenced by the controller.
Sensor/Transducer: The sensor is responsible for measuring the actual output or the current state of the plant. It converts the physical quantity (e.g., temperature, position, pressure) into an electrical signal that the controller can interpret.
Controller: The controller is the "brain" of the feedback control system. It receives the information from the sensor about the current state of the plant and compares it to the desired or reference state (setpoint). The controller then calculates the error, which is the difference between the desired state and the actual state.
Error Signal: The error signal is the difference between the desired state (setpoint) and the actual state of the plant. It represents the deviation or discrepancy between the desired and current conditions.
Actuator: The actuator is the part of the system that receives the control signal from the controller and takes action to adjust the plant's behavior. It could be a motor, a valve, a heater, or any device that can modify the system's behavior based on the controller's instructions.
Feedback Path: This is the path through which the output information is fed back to the controller. The feedback loop allows the controller to continuously monitor the plant's performance and make adjustments to minimize the error over time.
The feedback control system works in a continuous loop:
The sensor measures the plant's current state and sends this information to the controller.
The controller compares the measured state with the desired state and calculates the error.
Based on the error signal, the controller determines the appropriate control action to be taken.
The controller sends the control signal to the actuator.
The actuator modifies the plant's behavior based on the control signal.
The process repeats as the system continuously adjusts and readjusts to maintain the desired state.
This continuous feedback loop allows the system to adapt and respond to changes and disturbances, ensuring that the controlled process remains stable and follows the desired performance.