Abstract: This paper compares the traditional control scheme and the AC servo technology control scheme for packaging machinery, and introduces the characteristics of AC servo technology. Keywords: Packaging machinery; AC servo technology Introduction In recent years, with the continuous development of AC servo technology, traditional high-power single-motor drives are gradually decreasing in more and more packaging machinery, being replaced by low-power multi-motor drives. 1. Shortcomings of Traditional Control Schemes Currently, the production speed of domestically produced packaging machinery in China is mainly below 60 pieces/min, while packaging machinery exceeding 120 pieces/min is still mainly imported. The key factor restricting the improvement of production speed is that there are many high-frequency positioning actions with synchronous relationships in packaging machinery. Traditionally, a single-motor drive plus clutch and brake scheme is used to control the start and stop of moving parts. Impact is unavoidable, leading to wear of the friction plates of the clutch or brake, reducing the working characteristics and affecting the accuracy of the action. It is impossible to achieve high-frequency, high-precision synchronous control. If the transmission ratio between moving parts is variable or the transmission chain is long, using a single-motor drive requires replacing many transmission parts, resulting in long operation cycles and high costs. For reciprocating motion components with time-sequential synchronization requirements, mechanical cams are traditionally used. However, mechanical cams have many insurmountable drawbacks: firstly, the cam profile is prone to wear, affecting motion accuracy; secondly, if the cam profile is complex or the cam speed exceeds 200 rpm, cam design and manufacturing become extremely difficult, significantly increasing equipment costs and maintenance expenses. Therefore, the extensive use of cams in packaging machinery also restricts the improvement of packaging speed. 2. Advantages of AC Servo Technology Control With the continuous emergence of new high-performance permanent magnet materials and the rapid development of power electronic devices, all-digital AC servo technology is becoming increasingly mature. The constant torque, high responsiveness, and maintenance-free characteristics of AC servo motors give them unparalleled advantages over ordinary motors in packaging machinery. In packaging machinery, AC servo motors are primarily controlled by position control. The system block diagram is as follows: When a certain number of command pulses are issued, the D/A converter outputs a speed command voltage based on the number of residual pulses in the deviation counter. This voltage drives the AC servo motor to rotate via the motor control unit. During rotation, feedback pulses from the position feedback encoder PG reduce the number of residual pulses in the deviation counter. When the number of residual pulses in the deviation counter reaches zero, the AC servo motor stops rotating. The motor speed is determined by the frequency of the command pulses, and the rotation angle is determined by the number of command pulses. Currently, mainstream AC servo systems on the market can achieve very high-precision motion control. Their encoder resolution can reach 131072 pulses/revolution or even higher. AC servo motors can accept high-speed pulse trains of 500kpps, with a speed frequency response exceeding 550Hz. The number of start-stop cycles per minute can reach hundreds to thousands depending on the motor model. Furthermore, with abundant software resources, they can fully meet the precision and speed requirements of modern packaging machinery, achieving high-frequency positioning actions with synchronous relationships, thus replacing clutches, brakes, and mechanical cams. 3 Conclusion With the widespread application of AC servo technology in packaging machinery, China's packaging machinery level will reach a new level. References: [1] Bian Wengang. Principle and application of electric AC servo technology [J]. Motor Technology, 1998. [2] John Rathkey Multi-axis Synchronization Technology Review [OL]. Industrial Control and Frequency Conversion Network, 2003-11-20. Author Introduction : Jiang Jianjun (1976-), male, assistant engineer of Luoyang Nanfeng Electromechanical Equipment Manufacturing Co., Ltd., Bachelor.