A control loop is a feedback mechanism that is used to control the behavior of a system or process. It is the basic building block of a control system and consists of the following components:
Process variable: This is the physical quantity that is being controlled, such as temperature, pressure, or position.
Setpoint: This is the desired value for the process variable, which represents the desired outcome of the control system.
Sensor: This is a device that measures the process variable and provides input to the control system.
Controller: This is the logic device in the control system that processes the input from the sensor and generates control signals for the actuator.
Actuator: This is the component of the control system that performs a physical task based on the control signals from the controller.
Feedback: This is the process of comparing the actual value of the process variable with the setpoint, and using that information to adjust the control signals and improving the performance of the control system.
The control loop operates in a continuous manner, constantly monitoring the process variable and making adjustments as needed to ensure that the process variable remains close to the setpoint. The feedback mechanism is critical to the success of the control system, as it allows for real-time correction of any deviations from the desired outcome, ensuring that the process remains stable and under control.