Servo systems are an indispensable part of industrial automation. Also known as follow-up systems, their main function is to provide feedback control for accurately following or replicating a process. Initially used primarily in defense and military applications, servo systems are now being adopted in fields such as automated machine tools and wireless tracking control.
A servo system mainly consists of three parts: a controller, a power drive unit, a feedback unit, and a motor. The controller adjusts the control input based on the difference between the setpoint of the CNC system and the actual operating value from the feedback unit. The power drive unit is the main circuit of the system, while the motor drives the mechanical movement according to the power supply.
The main functions of a servo system are threefold:
1. Use low-power command signals to control high-power loads;
2. In the absence of a mechanical connection, the input shaft controls the output shaft located at a remote distance, achieving remote synchronous transmission;
3. To enable the output mechanical displacement to accurately track electrical signals, such as in recording and indicating instruments.
A servo system can follow input values based on parameters such as the position, orientation, and state of an object. Its main task is to change the magnitude of parameters according to control commands, so that the torque, speed, and position of the equipment in the system can be zeroed or changed.
With the current development of production, the requirements for servo systems are becoming increasingly stringent, driving them towards higher precision, higher speed, and higher power. By combining electronic and computer technologies, digital servo systems can be implemented, effectively eliminating factors such as nonlinear errors and further improving their performance. Currently, the speed ratio of AC servo motors has reached 1 : 10000 . Brushless motors, due to the absence of brushes and commutator components, offer acceleration performance twice that of DC servo motors and are easier to maintain, typically used in high-speed CNC machine tools.
