Sensors: Sensors play a critical role in a closed loop control system by measuring process values that require regulation. For example, in a hydraulic axis, a position sensor is attached to the hydraulic cylinder to monitor the axis’s position. These sensors provide valuable data on position, velocity, acceleration, and other relevant parameters.

Actuators: Actuators are the components responsible for adjusting the process to maintain regulation. For instance, in the case of the hydraulic axis, the actuator would be the hydraulic cylinder itself, responsible for adjusting the position based on control signals.

Field Bus Systems: Field bus systems serve as the communication backbone of the closed loop control system. They facilitate the real-time transfer of data from sensors to the central processing unit (CPU) and control signals from the CPU to the actuators.

Central Processing Unit (CPU): The CPU, often a Programmable Logic Controller (PLC) in industrial settings, is the heart of the closed loop control system. It receives data from sensors via the field bus system, processes the information, and calculates the control algorithm to minimize the error between the setpoint and the actual output.

Control Algorithm: The control algorithm is the core of the closed loop control system. It compares the desired setpoint with the actual output and calculates the control signals needed to minimize the error. The goal is to maintain the error as close to zero as possible, achieving stable and precise regulation.