Interpretation of the development trend of industrial servo drive and control system industry

1. Industry Overview

Industrial servo drive and control system refers to an automated control system that is composed of control quantities such as displacement, speed, angle, etc. of an object and can track any changes in the target. It is an extended product based on frequency conversion technology. It can not only perform speed and torque control, but also achieve precise, fast and stable position control. The industrial servo drive and control system mainly consists of three parts: servo drive, servo motor and encoder. The servo drive is responsible for decomposing the information received from the controller into executable commands for a single degree of freedom system, and then passing it to the actuator (servo motor); the servo motor converts the received current signal into torque and speed to drive the control object, realizing the control of each joint angle, angular velocity and joint torque; the encoder, as a feedback device of the servo system, largely determines the accuracy of the servo system.

The encoder is installed on the servo motor and rotates synchronously with the motor. While rotating, it sends the coded signal back to the controller, which determines the direction, speed, and position information of the servo motor. According to the different actuators, the servo system can be divided into hydraulic servo system, electrical servo system and pneumatic servo system. At present, the most widely used is the electrical servo system. The electrical servo system can be further divided into DC servo system and AC servo system. Among them, the DC servo motor can realize the precise and fast start or stop function, so it is mostly used in equipment that can be controlled by a microcontroller or computer. The AC servo motor contains an encoder, which provides closed-loop control and feedback together with the controller. It has a higher operating voltage, greater torque, and higher precision. It is mainly used in mechanical equipment such as robots and automation equipment.

(1) Servo drive

A servo drive is a device that achieves high-precision positioning of a transmission system by controlling a servo motor. It is the hub of signal conversion and amplification in servo drives and control systems. It combines and amplifies input and feedback signals, and outputs corresponding signals to control the forward or reverse rotation of the servo motor according to the polarity of the combined signal. When the input signal is balanced with the feedback signal, the servo motor stops rotating and its end actuator stabilizes at a specific position.

(2) Servo motor

As the actuator in the servo drive and control system, the servo motor converts the signal of the servo drive into the angular displacement and angular velocity of the motor. The servo motor is mainly composed of a stator and a rotor. The stator is equipped with an excitation winding and a control winding. The rotor inside is a permanent magnet or an induction coil. The rotor rotates under the action of the rotating magnetic field generated by the excitation winding. Servo motors are divided into two categories: DC servo motors and AC servo motors. Unlike ordinary motors, servo motors are usually integrated with encoders to achieve closed-loop control and precise control. The performance indicators of servo motors have obvious advantages over ordinary motors in terms of overload capacity, speed regulation range and response speed.

2. Industry development trend

At present, industrial servo drive and control systems are developing towards digitalization, miniaturization, intelligence and high performance, which are mainly reflected in the following aspects:

(1) AC servo control technology

AC servo control technology will become the main development direction of industrial servo drive and control systems, and will develop in the direction of high performance, full digitalization, intelligence and software. This type of servo system includes three major systems: speed loop control, position loop control and current loop control, and can complete internal communication through application software. It will become the mainstream direction of the development of AC servo systems.

(2) Intelligent Power Integrated Circuit

The power electronic devices used in industrial servo systems will continue to develop towards high frequency, and intelligent power integrated circuits will be further widely used. Since integrated circuits have the advantages of small area, high reliability, easy integration and long service life, traditional controllers and other modules that are difficult to control accurately can be implemented using integrated circuits, and the combination of digital and analog methods can be used to further improve their accuracy and the stability of the entire system.

3. Opportunities

(1) Intelligent manufacturing continues to drive market demand growth

In recent years, emerging technology fields such as the Internet of Things, 5G, cloud computing, big data, artificial intelligence, and smart driving have gradually begun the process of commercialization and industrialization. They will effectively promote the intelligent manufacturing process of industrial production and promote China's manufacturing industry to develop in the direction of intelligence and flexibility, increase production and sales, and reduce operating costs, thereby driving the continued growth of the market demand for automation products in the field of industrial servo drives and control systems.

(2) The continuous improvement of domestic production level promotes import substitution

As the technical level of domestic automation equipment manufacturers continues to improve, the localization rate in the field of industrial servo drive and control systems in my country continues to increase. Since 2010, local companies have successively entered the capital market, their comprehensive strength has been greatly enhanced, and the industry has entered a period of rapid development. Compared with foreign brands, local brands are closer to the actual needs of domestic customers, have more timely service responses, and their market share continues to increase.

(3) Downstream application areas continue to expand and update

Industrial servo drives and control systems are widely used in various fields of the national economy, such as building materials, papermaking, machine tools, elevators, chemicals, metallurgy, coal, textile machinery, plastic machinery, printing machinery, packaging machinery, food and beverage machinery and other traditional fields, as well as emerging industries such as electronic manufacturing equipment and industrial robots. In addition, automation products in the field of industrial servo drives and control systems are also widely used in emerging fields such as urban rail transit, electric vehicles, and new energy power generation. They not only effectively meet the incremental market demand generated by the expansion of emerging industries, but also continue to meet the stock market demand with the development and renewal of traditional industries.