Li Jingyang of Beijing Wowa Innovation Technology Co., Ltd. mainly introduced the application of Schneider Electric's servo control system on the three-drum one-step molding machine at Beijing ShouChuang Tire Factory. 1. Introduction In recent years, the vigorous development of the automotive industry and highways has driven the rapid development and continuous technological updates of the rubber industry, especially in the last year or two, with a continuous increase in radial tire projects. The world's top ten tire manufacturers have all established factories in the Chinese market through cooperation in different forms, bringing their most advanced processes and equipment to the country. Expanding production capacity and improving technology have become top priorities for tire companies, including domestic ones. In this wave, the semi-steel one-step molding machine is particularly favored. Along with the booming development of rubber machinery in China in recent years, Beijing ShouChuang Tire Co., Ltd. began its new factory relocation project in the third quarter of 2005. The 4 million sets of semi-steel one-step molding machines, a core component of the new factory relocation project, a key project of Beijing Municipality, are a product of the excellent combination of high technology and the rubber industry. Beijing Wohua Innovation Technology Co., Ltd., as the system integrator for this project, after careful review, ultimately decided to primarily use Schneider Electric's products for the electrical control system of the molding machine. This decision was based on the following considerations: Schneider Electric has a relatively complete product line, avoiding the involvement of multiple suppliers during system construction, facilitating configuration and maintenance, and offering greater hardware compatibility. Furthermore, compared to other internationally renowned automation equipment manufacturers of the same level and performance, Schneider Electric offers advantages such as ease of operation and cost-effectiveness. 2. Process Characteristics and System Setup The three-drum semi-steel one-step tire molding machine consists of a main unit, a carcass feeding rack, a belt layer feeding rack, a tread feeding rack, a crown strip feeding rack, a pneumatic system, and an electrical control system. Under the control of the electrical control system, the molding machine sequentially applies and wraps the PA pre-composite components and cord fabric on the carcass forming drum. The formed carcass components are then transported to the sizing drum via the main unit's transfer ring. Once the belt layer, crown strip, and tread are bonded together, they are inflated and pressed together on the sizing drum to form the tire blank. Furthermore, the entire tire blank forming process must be completed within 1.5 minutes. To meet this requirement, each feeding rack must be able to automatically prepare materials to a fixed length. When the main drum material is applied, each feeding unit must be able to feed synchronously. The crown strip should be able to complete different winding methods according to the process requirements. When producing tires of different specifications, the touchscreen should provide an easy-to-use formula switching function. Due to the high degree of automation required, the one-step forming machine demands extremely high precision and speed throughout the entire process. Therefore, we adopted Schneider Electric's overall solution. Specifically, we selected the Schneider Electric PREMIUM series CPU—TSX574823—for the PLC. This CPU integrates an Ethernet interface and a CANopen bus interface, allowing the human-machine interface and speed control unit to connect to the main CPU via Ethernet and CAN bus, respectively. The remote I/O of each slave station is connected via Schneider's internal bus BUS-X. The core of this equipment (servo control section) utilizes Schneider's TSXCSY16A axis control module in conjunction with SERCOS fiber optic ring network technology to control the LEXIUM17 series servo drives, thereby fulfilling the different process requirements of different parts of the forming machine. The specific network structure is shown in Figure 1. [IMG=Figure 1]/uploadpic/THESIS/2007/11/2007111611372684917F.jpg[/IMG] Figure 1 3 Core Application Introduction Since the semi-steel one-step forming machine is a typical motion control system, the servo control system plays a crucial role in the entire automated control. In the tire forming process, motion control requires the implementation of the following key technologies: 3.1 Manual mode: Responding to the operator's manual operation under constant torque. (Operation in various manual modes) 3.2 Fixed length control: Feeding a fixed length of material strip according to different specifications. (e.g., automatic material preparation of each feeding unit) 3.3 Combined axis control: When one part of the equipment moves, other parts are required to move synchronously at the same speed or at a certain speed ratio. (e.g., material adhering to the drum) 3.4 Interpolation control: When different parts of the equipment complete different actions, timing is required to match. (e.g., the winding of the crown strip) The author will also briefly describe the control scheme of the servo part in this project based on his own practical application experience: Table 1 lists the specific selection and configuration of the servo system in this project, and the specific control scheme of each axis is shown in Table 2. Table 1 Table 2 This system uses ten LEXIUM17 series servo controllers, that is, ten control axes. Therefore, we selected a 16-axis Schneider PLC-based servo control module TSXSCY164 to control these ten servo drives and downstream motors through SERCOS fiber optic network technology. As shown in Figure 2. (1) The manual control part of this system is implemented by selecting the control mode of the servo controller, that is, selecting the MANUAL mode. In this mode, we can cooperate with the signal acquisition of the PLC's digital signal input module to complete the response to the operator's operation. The FUNCTION CODE involved in the operation is 2572 (mode selection). In this mode, we can complete the manual constant torque rotation of each drum, start and stop control, and manual control of feeding of the feeding rack. (2) In the automatic length setting part of the automatic material preparation process of each feeding rack, we adopted the INCR_MOVE (relative position) scheme, that is, based on the current position, it moves a fixed length. This scheme solves the problem of finding the origin in the continuous production process, and can complete the repeated and accurate length setting of the material without finding the origin. The FUNCTION CODE involved in this operation is 513 (motion mode selection). In this mode, the servo motor will rotate to a specific position at a certain speed. Through this function of the servo system, we can complete the repetitive process of automatically cutting and conveying the material to the front section of the feeding rack at a certain speed, waiting for the next bonding process. (3) For the synchronous bonding process, we adopted the Following Function scheme, that is, we built a new combined shaft, which consists of two or more shafts, including a master shaft and several slave shafts. When the master shaft rotates, the slave shafts rotate according to a certain speed ratio. The main FUNCTION CODEs involved in this operation are 513 (motion mode selection) and 2114 (modification of the speed ratio between the master and slave shafts). We applied this scheme in the molding machine to solve the problem of material stretching and accumulation caused by the mismatch between the feeding speed and start-up time of the feeding rack and the rotation of the drum when the material is automatically bonded on the drum. (4) Because zero-degree tires require a large bonding joint during bonding, resulting in poor tire dynamic balance, most current tire manufacturing processes use crown strips to replace zero-degree tires. In our semi-steel one-step forming machine project, the user requested different winding methods for crown strips under different formulations. We adopted the Co-ordinated Axes solution. That is, a new interpolation combination shaft is created. In application, we use the crown strip servo as the master shaft and the bonding drum as the slave shaft. The main FUNCTION CODE involved in this operation is 513 (motion mode selection). By using this solution, we successfully solved the user's requirements for different crown strip winding methods and the difficulty of relatively independent movements between the crown strip and the drum during the crown strip winding process, while the timing required to match. 4 Application Summary By using Schneider Electric's complete MOTION solution, we successfully solved a series of problems requiring high automation, fast response speed, high precision, and simple operation for the semi-steel one-step forming machine. This enabled the forming machine to reach the international advanced level. This invention solves the problem of low localization efficiency of imported equipment, making it a new type of molding machine suitable for the specific conditions of China's rubber and plastics industry. It has also received positive feedback from end users. (Proceedings of the 2nd Servo and Motion Control Forum; Proceedings of the 3rd Servo and Motion Control Forum)