This paper focuses on the application of variable frequency servo technology in the saw blade punching process. The solution uses automated electromechanical control technology to replace the traction part of the original turbine-worm gear system in the saw blade punching machine. The tooth pitch control is entirely completed by the servo tracking the variable frequency position in real time; changes in tooth pitch only require modification of the servo parameters. 1 Introduction The carding machine is a front-end process equipment in textile engineering. The carding saw blade is a key component of the carding machine (Figure 1). Punching is the main processing technology of the carding saw blade. Traditionally, punching and traction are completed by a mechanical mechanism integrating a turbine and worm gear. Different tooth pitches require different turbine reduction ratios. Behind the cumbersome mechanical installation and debugging, the processing accuracy also has a certain degree of random fluctuation. The newly designed servo system replaces the traction part of the original turbine-worm gear system. Punching is completed independently by variable frequency, and the tooth pitch control is entirely completed by the servo tracking the variable frequency position in real time. Changes in tooth pitch only require modification of the servo parameters. This not only has high efficiency but also excellent consistency in the processed tooth pitch. This servo system represents a completely new concept and a qualitative leap for the industry (Figure 2). 2. Principle Design 2.1 System Process and Control Analysis The mechanical equivalent architecture is shown in Figure 3. When the tension of the production line changes, the frequency converter adjusts its PI according to the tension feedback. Since the tension link has low process requirements, it is easy to control. When the speed of the frequency converter changes, the cutting speed of the file on the roller changes accordingly. To ensure a constant punch pitch, the servo system at the back end needs to accurately track the speed of the frequency converter in real time. Based on the ratio of frequency converter speed to tooth pitch, the target accuracy of pulse equivalent accuracy is ensured to be less than one-tenth, and the frequency of the feedback encoder at the maximum speed of the motor is ensured to be less than 500KHZ. Therefore, the resolution of the feedback encoder of the tracked motor is selected as 1000PPR. The tooth pitch is changed by directly modifying the electronic gear ratio of the servo through the RS-485 communication function between the PLC and the servo. 2.2 Saw Blade Control Scheme The saw blade control system scheme is shown in Figure 3. The entire automation system is implemented by Delta Electromechanical Automation products. This includes a Delta DVP14ES00T programmable controller and a Delta ASD-A0421LA/ASMT04L250AK 400W servo system (servo motor drive reduction ratio: 10:1). The encoder requires differential output/AB phase/1000PPR/DC5V. [IMG=Figure 1 Carding Saw Blade]/uploadpic/THESIS/2007/11/2007111614104257655V.jpg[/IMG] Figure 1 Carding Saw Blade [IMG=Figure 2 Saw Blade Punch Servo System]/uploadpic/THESIS/2007/11/2007111614132867742A.jpg[/IMG] Figure 2 Saw Blade Punch Servo System [IMG=Figure 3 Mechanical Equivalent Architecture]/uploadpic/THESIS/2007/11/2007111614145814540Y.jpg[/IMG] Figure 3 Mechanical Equivalent Architecture [IMG=Figure 4 [Saw Blade Control System]/uploadpic/THESIS/2007/11/2007111614162242297V.jpg[/IMG] Figure 4 Saw Blade Control System 3 Analysis of Core Technologies of Control System The stable control of the tooth pitch ultimately boils down to how the servo system can accurately track the encoder control problem. To overcome the dynamic/static friction in this mechanical system, improving the rigidity of the servo is a prerequisite for stable pulse tracking. If rigidity is simply increased (bandwidth/FW), the pulse tracking error will decrease significantly to about 4 when the bandwidth reaches 120Hz. However, due to the discrete errors of the tracked asynchronous motor slip rate and mechanical components, the encoder pulse source will exhibit some random fluctuations. Furthermore, an excessively large ratio can easily lead to "output overshoot and oscillation" in the deviation control, and the combined effect of the speed integral stage on phase shift causes significant fluctuations in the tracking error, with approximately 1/6 of the tooth pitch exceeding the allowable error range. Therefore, the key control objective of this servo system is to stabilize the tracking error rather than to reduce it. Based on the above analysis, appropriately adjusting the servo system bandwidth to 80Hz, adjusting the speed ratio to around 2700, reducing the position feedforward gain to around 1500, and significantly reducing the speed integral to around 35 significantly improves the accuracy, with most tooth pitches even reaching the user's "zero error standard." 4. Conclusion The servo control system for carding saw blade punching based on Delta Electromechanical technology has been successfully put into operation. Project practice has proven that the solution not only fully achieved the expected design results but also provided a good economic solution for other similar industries. In similar servo synchronous control applications, such as winding pitch control in the wrapping machine industry and petal width control in the glass grinding machine industry, the above control model was ultimately adopted, demonstrating significant reference and scalability in system design concepts. (Proceedings of the 2nd and 3rd Servo and Motion Control Forums)