A servo system is a motion control component consisting of a servo drive and a servo motor. The servo drive refers to the power electronic device that controls the angle, speed, and torque of the servo motor, and belongs to the drive layer. Servo motor refers to the engine that controls the operation of mechanical components in the servo system. It is an auxiliary motor indirect speed change device and belongs to the executive sensing layer.

In the servo system, the servo driver sends a signal to the servo motor to drive its rotation. At the same time, the encoder feeds back the motion parameters of the servo motor to the servo driver. The servo driver then summarizes, analyzes and corrects the signal. The speed is the control quantity, which dynamically tracks the change of the target position.

According to the size of the power, the servo system can be divided into small servo, medium servo and large servo system. According to the different implementation components, it can be divided into hydraulic servo system, electrical servo system and pneumatic servo system, and the electrical servo system can be divided into DC servo system and AC servo system.

There are differences between DC servo and AC servo in principle, control mode and performance. Compared with AC servo, DC servo is widely used in AGV, medical equipment, instrumentation and other fields due to its advantages of simple structure, reliable operation, convenient maintenance, and high operating efficiency. For printing equipment, laser processing, robots, machine tool equipment, manipulators and other industrial production lines that have higher requirements for control accuracy, speed and torque.

According to different control and adjustment principles, it can be divided into open-loop servo system, closed-loop servo system, and semi-closed-loop servo system. The open-loop servo system is a system without position feedback, and its driving components are mainly power stepping motors or hydraulic pulse motors. The closed-loop servo system is an error control follow-up system. The actuator cannot reflect the position of the movement, and a position detection device is required. The control structure of the closed-loop servo system is the same as that of the open-loop system.

Open loop servo system structure

The servo system is an industrial automation control product. The technical difficulties mainly lie in whether it has the self-adjustment function, the response speed of the servo driver, and the electromagnetic design technology. Product with high reliability and stability.

Relying on the technology application experience accumulated in the industry for a long time, leading foreign manufacturers still have relatively high competitive advantages in terms of control performance, product reliability, software core algorithms and overall solutions. The research on servo system in our country started relatively late, and domestic manufacturers started the research and development of civilian servo system after 2000. At present, my country has completed the research and development and mass production of low-end servo systems, and high-end servo technology is still in the research and development stage.

As the main raw material for the production of magnetic materials - rare earth, the raw material, reserves and output rank first in the world, and will maintain a long-term loose supply in the future. The overall upstream supply is relatively loose. As an indispensable component of the servo system, encoders and sensors are supported by national policies, and key technologies have made continuous breakthroughs. However, with the rise of raw material prices, the manufacturing cost of servo enterprises has also risen.

From the perspective of market share, my country's domestic servo market share continues to increase, mainly in the field of small servo breakthroughs, most of the market is still occupied by foreign brands. Among them, Japanese brands account for the largest proportion, mainly including Panasonic, Mitsubishi Electric, Yaskawa, Fuji, Sanyo and other old Japanese industrial automation equipment manufacturers. Secondly, European and American brands mainly occupy the medium and large servo system market, mainly including American brands such as Rockwell, Danaher, and Paguang, and German brands such as Siemens, Bosch Rexroth, Lenz, and Schneider.