Abstract: Servo drive products have been widely used in the machine tool and CNC machining industries. This article briefly introduces the development direction of the next generation of servo drives and discusses the characteristics of the next generation of servo products in detail, proposing that the next generation of servo products will inevitably be widely used due to their functional characteristics. The article also introduces the ELMO intelligent servo drive and the Yokogawa DD precision direct drive motor promoted by Tianjin Luosheng Enterprise Co., Ltd. Keywords: DD motor, ELMO servo, precision, intelligence Abstract: Servo drive products have been used abroad in the machine and CNC industry. This paper briefly introduces the development direction and characteristics of the new generation servo driver. Due to the characteristics and functions of the new generation servo, it is expected to be widely used in the future. The intelligent servo driver and high-accuracy direct driver, Yokogawa DD motor, supplied by Tianjin Acepillar, is also introduced. Keywords: DD motor, ELMO servo driver, accuracy, intelligence 0 Introduction In recent years, the domestic industrial automation field has shown rapid development. Advanced foreign technologies have been rapidly introduced and popularized. Among them, servo drives, as an important representative product in the drive field, have been widely accepted by users and have played a crucial role in machine innovation. Precise drive effect and intelligent motion control can perfectly realize the efficient automation of machines through servo products. These two aspects have also become important indicators of servo development. 1 Introduction to Servo Systems Servo drive technology is an important component of CNC technology. In conjunction with CNC devices, the static and dynamic characteristics of servo systems directly affect the displacement speed, positioning accuracy, and machining accuracy of machine tools. Currently, DC servo systems have been replaced by AC digital servo systems; the position, speed, and current loops of servo motors are all digitized; and new control theories have been adopted to achieve a high-speed response system unaffected by changes in mechanical load (Figure 1). Key new technologies include: a. Feedforward control technology. Past servo systems multiplied the difference between the detector signal and the position command by the position loop gain to obtain the speed command. This control method always suffers from tracking lag error, which degrades machining accuracy when machining corners and arcs. Feedforward control adds a speed command control method to the original control system, significantly reducing the tracking lag error of the servo system. b. Nonlinear control technology for mechanical static friction. For some CNC machine tools with significant static friction, the new digital servo system has a nonlinear control function to compensate for the static friction of the machine tool drive system. c. The position loop and speed loop (including the current loop) of the servo system are both controlled by software, such as digital adjustment and vector control. To adapt to different types of machine tools, different precision requirements, and different speeds, acceleration and deceleration performance is pre-adjusted. d. High-resolution position detection devices are adopted. For example, high-resolution pulse encoders with microprocessor-based subdivision circuits greatly improve resolution, with incremental position detection exceeding 10,000 p/r (pulses per revolution) and absolute position detection exceeding 1,000,000 p/r. e. Compensation technology has been developed and applied. Modern CNC systems all have compensation functions, which can perform various compensations on servo systems, such as lead screw pitch error compensation, tooth backlash compensation, axial motion error compensation, spatial error compensation, and thermal deformation compensation. 2 New Generation Precision Servo Products Precision refers to the high degree of consistency between the execution effect achieved by servo drive and the target setting, and good control precision. To achieve such results, targeted design and manufacturing are required for both the actuator (motor) and the drive device (driver). Yokogawa's DDM products are a very typical example of such products. The following introduces the DD motor from three aspects: First, backlash error is eliminated. Ordinary transmission mechanisms, due to intermediate components such as reducers, couplings, gears, belts, or lead screws, inevitably suffer from backlash errors, especially with the mechanical wear caused by prolonged operation, which is often uncompensable. DD motors effectively solve these problems. Due to the direct-drive installation method (Figure 2), errors are minimized; moreover, its servo characteristics allow for real-time error correction, achieving optimal control precision. Secondly, they offer high resolution and high positioning accuracy. The encoders available for DYNASERV DD motors have very high resolution; the DM1B-045 has a resolution of 655,360 PPR (the DM-A series reaches 4,096,000 PPR), resulting in high electrical control precision, exceeding that of ordinary servos by an order of magnitude. Due to their highly precise manufacturing, the final control accuracy can generally be within 2 seconds. Thirdly, they offer high rigidity, a compact structure, and high efficiency. DD motors are very rigid and exhibit a stiff characteristic when combined with a load, placing higher demands on their drivers. The latest DYNASERV drivers offer online gain adjustment and resonance filtering. The unique hollow design of the motor not only reduces its own inertia but also provides customers with more installation options. The combined mechanical structure is more compact and has the highest efficiency compared to other methods. The DD motor has a relatively low speed, with a rated speed of approximately 60rpm to 240rpm. However, this speed refers to the final speed on the turntable, which is a significant advantage compared to the ordinary servo + reducer architecture. While maintaining the speed, the DD motor maintains high output torque. Due to the use of a permanent magnet stator, the torque output curve of the Yokogawa DD motor maintains a smooth and linear characteristic within the rated speed range (Figure 3). Yokogawa's GIII driver uses I-PD control. For the same current loop bandwidth, the GIII driver using I-PD control achieves a 10Hz position loop bandwidth, reducing the speed bandwidth by 2.5 times compared to the traditional PID control method. This characteristic determines the high rigidity (position bandwidth) of the motor. In terms of applications, Yokogawa DDM products are also at the forefront, covering multiple fields of industrial machinery such as self-adhesive label printing machines, LCD production lines, DVD/CVD production equipment, IC testing equipment, semiconductor manufacturing equipment, and electronic manufacturing equipment. The self-adhesive label printing machine adopts a flatbed structure design and mainly completes the following processes: paper feeding, printing (secondary overprinting), embossing, hot stamping, cutting or rewinding, and counting. The printing speed is 60-180 times/minute. The measured value for a single printing is <0.03, and the measured value for secondary overprinting is <0.035 (statistical values). The DD motor is mainly used to drive the rollers. As shown in the control principle diagram 5, during the first printing, the single-axis controller SPC007 controls the travel length and speed of the DD motor, and the printing plate is printed with colors on both sides. During secondary overprinting, the color mark sensor scans the mark point and notifies the SPC007 to control the DD movement in mark tracking mode, and the printing plate is overprinted with colors on both sides. The travel distance and speed can be set by a master DIP switch or a human-machine interface. Compared to older models, this saves manpower, especially for color matching issues, which are entirely handled by the controller. It avoids the frequent mechanical adjustments caused by mechanical errors, greatly improving work efficiency. Furthermore, maintenance is simple and the equipment is safe. Yokogawa DD motors are primarily used in the LCD and semiconductor industries. Figure 6 shows their application in dicing machines, and Figure 7 shows their application in IC sorting machines, both utilizing the high precision, high rigidity, simple direct connection structure, long lifespan, and ease of maintenance of DD motors. Currently, they have a significant market share in China. 3. New Generation Intelligent Servo Products Intelligence refers to the ability of servo products to intelligently drive and control. The driving capability, control effect, programmability, and openness of information communication with the upper-level control system are the basic indicators for measuring the intelligence of a drive product. From simple modules built with analog thyristor drive circuits to today's fully digital AC drives, driver innovation has never stopped in just over a decade. The following introduction to the Israeli ELMO drive will familiarize more people in China with the world's most advanced development direction. Elmo's drivers are designed with an "active" approach, employing proprietary chip circuitry to ensure a smooth transition throughout the entire process. Compared to traditional RC "passive" conversion methods, current surges and losses during startup and shutdown are significantly reduced, resulting in very low EMI. All Elmo drivers (using MOSFETs or IGBTs) achieve fast and efficient power conversion with energy losses not exceeding 3%. Regarding energy consumption, Elmo emphasizes thermal management, prioritizing low energy loss while effectively dissipating heat. Its unique ceramic-mounted heat dissipation technology guarantees 100% heat dissipation. For fast and powerful integration of motors and drivers, Elmo introduced SimplIQ technology (Figure 8), featuring multiple feedback selection programming capabilities, standard signal monitoring technology, and excellent motion control technology, simplifying the control process and enabling machines to operate under ideal conditions. Elmo drives boast unique advanced position control features including point-to-point motion, PT (Position Time Schedule), PVT (Position Speed ​​Time), ECAM (Electronic Cam), position following pulse input, dual-loop, fast event capture, fast output comparison [OC], event-capture interrupt, and event-triggered programming. Elmo drives also feature unique designs in advanced filtering and gain pre-setting modes, including speed and current gain setting in non-operating states, speed-position PIP control, automatic rectification modulation, and automatic motor phase sequencing. Communication methods support RS-232, CANopen DS-301, and DS-402. Elmo's controller, Maestro, is a network-based multi-axis motion controller and monitor (Figure 9). Used in conjunction with Elmo's own intelligent drives, it enables complex multi-axis motion control. The motion control network built using Maestro and SimpleIQ drives is based on a distributed motion control network architecture. It supports synchronous motion control, sequential motion control, multi-axis motion recording and analysis tools, and multi-axis application development systems. Adjustment, monitoring, and general analysis of each axis are performed via direct Ethernet access. [align=center] [/align] In aerospace, medical, packaging and other industrial machinery, Elmo drives have also been widely used due to their own characteristics. [align=center] Figure 10 Application of Elmo drives in printing presses[/align] In Figure 10, two Elmo drives are connected by auxiliary feedback. The slave axis follows the master axis to complete the ECAM function. The required motion control can be completed without a controller. Figure 11 shows the application of winding machine. One of them follows the encoder to complete the ECAM function. One of the other two drives is the master and the other is the slave to complete the ECAM function. Therefore, the motion control of the winding machine can be completed without a controller. 4 Conclusions Precise positioning and intelligent control will continue to develop in depth in the future. The structural revolution of mechatronics and the mutual penetration of drive and control will become the new trend that dominates the market in the next few years. Tianjin Luosheng Enterprise Co., Ltd. has also been committed to this development direction, promoting the introduction and promotion of advanced industrial motion control products in China. Gradually, some domestic products (in terms of motor drive) will approach the international advanced level and occupy a place in the world. References [1] Ge Suoliang, Liu Wenwei. Design of AC servo system based on fuzzy control. Journal of Southeast University (Natural Science Edition) 2006, S1. [2] Li Junhong, Chen Chaotian, Tang Zhongping. Variable structure control of AC permanent magnet synchronous motor servo system. Micromotors 2006, Vol. 32, No. 1. [3] Hu Qingbo, Hu Haibing, Lü Zhengyu. All-digital servo control system based on AC permanent magnet synchronous motor. Power Technology Application, May 19, 2006. [4] Feng LL, Moyne JR, Tilbury DM. Performance Evaluation of Control Networks: Ethernet, Control Net, and Device Net[J]. IEEE Control System Magazine, 2006, 21 (1): 66-83 [5] TM Jahnsm, WLSoong. Pulsating Torque Minimitation Techniques for Permanent Magnet AC Drives-A Review IEETrans[J]. on Industrial Electronics, 2006, IE-43 (2): 321-330 [6] Yokogawa Electric Corporation. Direct Driver Motor Intelligent Driver Technical Information Author Biography: Zhao Qi, male, born in 1981, Han nationality, Servo Products Department, Tianjin Luosheng Enterprise Co., Ltd.