Servo motor has become a hot topic in the CNC machine tool industry

The characteristics of servo motor systems have always been an important indicator affecting the machining performance of the system. In recent years, various servo motor drive technologies have been developed to improve the dynamic and static characteristics of servo systems. It can be foreseen that with the development of advanced manufacturing technologies such as ultra high speed cutting, ultra precision machining, and networked manufacturing, fully digital servo motor systems with network interfaces, linear motors, and high-speed electric spindles will become the focus of attention and the development direction of servo systems in the CNC machine tool industry.

1. AC servo motor

Servo motor technology will continue to rapidly shift from DC servo systems to AC servo systems. From the current situation of the international market, almost all new products are AC servo systems. The market share of AC servo motors has exceeded 80%. There are more and more servo motor manufacturers, gradually surpassing DC servo motor manufacturers. It can be foreseen that in the near future, AC servo motors will completely replace DC servo motors, except in some micro motor fields.

2. Fully digitized servo motor

The servo control unit using a new high-speed microprocessor and dedicated digital signal processor (DSP) will completely replace the servo control unit based on analog electronic devices, achieving a fully digital servo system. The implementation of full digitalization transforms the original hardware servo control into software servo control, making it possible to apply advanced algorithms of modern control theories such as control, artificial intelligence, fuzzy control, neural networks, etc. to servo systems.

3. The servo motor adopts new power electronic semiconductor devices

At present, the output devices of servo control systems mostly use new high switching frequency power semiconductor devices, mainly including high-power transistors (GTRs), power field-effect transistors (MOSFETs), and insulated gate transistors (IGBTs). The application of these advanced devices greatly reduces the power consumption of the servo unit output circuit, improves the system's response speed, and reduces operating noise. Especially, servo control systems have begun to use a new module called Intelligent Power Module (IPM) with integrated control circuit functions and high-power electronic switching devices. This device integrates functions such as input isolation, energy consumption braking, over temperature, over voltage, over current protection, and fault diagnosis into a small module. Its input logic level is fully compatible with TTL signals and can be directly interfaced with the microprocessor output. Its application greatly simplifies the design of servo units, achieving miniaturization and miniaturization of servo systems.

4. Highly integrated servo motor

The new servo system product has changed the previous practice of dividing the servo system into two major modules: speed servo unit and position servo unit, and replaced them with a single, highly integrated, and multifunctional control unit. By setting system parameters through software, the performance of the same control unit can be changed. It can not only utilize the sensors configured by the servo motor to form a semi closed loop adjustment system, but also form a high-precision full closed loop adjustment system with external position, speed, or torque sensors through interfaces. High integration also greatly reduces the volume of the entire control system, simplifying the installation and debugging of the servo system.