Abstract: This paper introduces the electronic cam (CAM) function of the Delta DVP-20PM00D motion controller, and elaborates on the working principle, process requirements, and related control program overview of the high-speed winding machine. Keywords: Motion control, electronic cam, spindle, slave axis, CAM Table 1 Introduction This paper introduces a fully automatic frameless series high-speed winding machine for hollow electromagnetic coils, which can wind drive coils, speaker coils, antenna coils, and various frameless general-purpose coils. The equipment features reliable performance, high speed and efficiency, and a high degree of automation, making it suitable for mass production in the coil manufacturing industry, as shown in Figure 1. Figure 1 shows a hollow electromagnetic coil. Ordinary winding machines typically use a small PLC with built-in pulse function. The speed output of the winding shaft encoder is sent to the PLC's built-in high-speed input point to achieve simple speed synchronization between the winding shaft and the guide shaft. This method is affected by PLC calculations, resulting in poor synchronization accuracy, a large computational load, and long CPU processing time. Consequently, problems such as uneven winding, accumulation, and collapse occur, severely impacting the quality of the finished winding product. For example, the PLC performs high-speed counting on the winding shaft encoder. When the count value is reached, an interrupt is used to control the guide shaft motor to reverse the winding. However, due to the CPU's processing time, a lag occurs, causing errors. While this can generally meet winding requirements at low speeds, it leads to uneven coil end faces and a decline in finished product quality when winding multi-layer coils at high speeds. Delta DVP-20PM00D is a dedicated motion control PLC. It adopts a high-speed dual-CPU structure and uses an independent CPU to process motion control algorithms. It can effectively realize various motion trajectory control, logic action control, linear/circular interpolation control, etc. In the high-speed winding machine, the electronic cam function of the 20PM motion controller is used to solve the problems of uneven winding, accumulation, and unevenness that occur when the winding direction is reversed, as shown in Figure 2. Figure 2 Motion controller DVP-20PM00D 2 High-speed winding machine 2.1 Introduction to equipment structure The high-speed winding machine consists of nine parts, as shown in Figure 3. Figure 3 High-speed winding machine (1) Frame. The frame is composed of an angle steel frame and a stainless steel table, and is equipped with casters for easy movement. When the equipment is in place, the legs can be lowered for stable support. (2) Tension mechanism. Installed in the wire inlet section, it is used for winding tension adjustment to ensure that the tension is constant during coil winding. The tension regulator has an adjustment knob to adjust the tension according to different needs. After adjustment, the tension regulator automatically controls the winding tension. (3) Winding mechanism. It mainly consists of Delta B-series 200W servo motor, synchronous toothed belt, and winding fly fork. It is the winding spindle in the electronic cam motion. The copper wire is wound onto the winding die head by the fly fork rotation. It is one of the main moving parts of the winding machine. (4) Wire laying mechanism. It includes Delta B-series 100W servo motor, precision linear screw, precision guide rail, pneumatic sliding fork, etc. It is the wire laying follower in the electronic cam motion. It follows the winding spindle in the forward and reverse reciprocating motion to realize the wire laying action. It is one of the main moving parts of the winding machine. (5) The working turntable consists of indexing stepper motor, rotary table, wire fork, and winding die head. This equipment is a multi-tasking winding machine. While winding, it performs processes such as die head preheating, wire cutting, heating, and demolding. This requires the working turntable to complete the operation according to different work positions. (6) Wire cutting mechanism. It is a pneumatic actuator. It mainly cuts the leads at both ends of the wound coil. (7) Demolding mechanism. Composed of an indexing stepper motor and a pneumatic demolding system, the finished product is removed from the winding die head. (8) Hot air system. The equipment is equipped with two adjustable temperature 220V hot air guns to preheat the die head before winding and to treat the coil with hot air after winding to facilitate demolding. (9) Electrical control. Includes an electrical control box and a touch screen operation box. The DVP-20PM00D motion controller is used as the control core, the touch screen is used for human-machine interaction, and the servo motor is used as the actuator to realize the precise control of the rotating shaft and the wire laying, thereby ensuring the accuracy of winding. The block diagram of the electrical control system is shown in Figure 4. Figure 4 Block diagram of electrical control system 2.2 Process flow Winding head returns to origin → feed to starting point → tension adjustment → die head preheating → winding and laying → heating → wire cutting → demolding → finished product → return to demolding point → feed to starting point for cyclic production. 2.3 Electrical system configuration The electrical control mainly includes the winding and laying part, the stepping indexing part, and the cylinder action control part. The specific configuration is shown in Table 1. Table 1 Electrical Control Configuration of Winding Machine 3 Delta PLC Electronic Cam Function The main control function of the high-speed winding machine is based on the application of Delta 20PM electronic cam, which greatly improves the finished product quality and efficiency of the winding product. The following is a brief introduction to the electronic cam function: 3.1 What is an electronic cam? See Figure 5. A cam is a mechanical structure used to realize the mechanical three-dimensional spatial linkage transmission relationship and control. The software system that uses software programs and servo motors to realize the three-dimensional spatial linkage transmission relationship and control in the automated motion control system is the electronic cam function. As can be seen from Figure 5, the left side is the common mechanical cam method, while the right side is the electronic cam method. That is to say, the trajectory required for mechanical cam control is completed by using a program (in conjunction with a servo unit) to realize the meshing motion of the main shaft and the driven shaft. Figure 4 Electronic Cam Function 3.2 Implementation of Electronic Cam (1) Obtaining the main shaft position. There are several ways to obtain the main shaft position: one is to use a virtual axis, which is simple and accurate to calculate; the other is to obtain it from the main shaft encoder or servo pulse and process the main shaft encoder signal; the third is to obtain it from the measuring encoder. After obtaining the encoder signal, it is converted into the main shaft position. (2) Achieve master-slave axis meshing. In fact, it is to define the relationship between the master and slave axes (called cam table). There are two ways to express the cam table: one is to use the point-to-point relationship of X and Y; the other is to use the functional relationship between the two. There are also multiple ways to obtain the cam table: according to the correspondence between points measured in actual work, or according to the standard functional relationship between the master and slave axes. The cam table can define multiple cam curves. After the relationship is determined and implemented, the position of the slave axis can be obtained according to the position of the master axis. 3.3 Electronic Cam of Delta Motion Control PLC In addition to realizing linear/circular interpolation and positioning functions, the Delta 20PM motion controller has an embedded electronic cam function, which makes it applicable to a variety of motion control occasions. The 20PM is a 2-axis motion controller with 2 channels of 500KHz input and output. In the electronic cam function, the X-axis is defined as the slave axis and the Y-axis as the master axis. After the cam table is defined, the slave axis follows the master axis according to the defined curve. Figure 6 is the main interface of the electronic cam graphical definition software. Figure 6 shows the main interface of Delta Electronic Cam Software's graphical definition. Within the software, we can clearly set and modify the electronic cam curve graphically. When we click the "Enter Data Form Settings" button, the following section settings table will pop up. Users need to first set Start Ang, End Ang, Stroke, and select the CAM curve (which has 6 types of curves including continuous, sinusoidal, and uniform acceleration, and can add other standard curves and custom curves) through the drop-down menu. After setting, press the "Setting completed" button to draw the displacement, velocity, and acceleration coordinates on the main screen, as shown in Figure 7. Figure 7 shows the graphical definition interface of Delta Electronic Cam Software. Figure 8 shows the electronic cam curve diagram using a high-speed winding machine as an example, employing CYCLIC mode for continuous forward and reverse winding from the slave axis according to the winding spindle. The following are the formulas for calculating the master-slave relationship: Distance of wire output (circumference) per revolution of the master shaft = π * D (mm) Or Distance of wire output (circumference) per revolution of the winding die = π * D (mm); Number of pulses required for one revolution of the slave shaft = 10000 P/R => Distance of movement of the ball screw per revolution = 10mm; Number of pulses required for one revolution of the master shaft = 3600 P/R => Number of pulses required for the slave shaft to rotate one revolution relative to the master shaft = 100 P/R => Distance of movement of the ball screw relative to the master shaft = 0.1mm Master/Slave relationship = (Number of pulses required for one revolution of the master shaft * Number of turns of the cam in one cycle) / (Number of pulses required for one revolution of the slave shaft * Wire diameter * Number of turns of the wire width) Figure 8 High-speed winding machine electronic cam curve Figure 4 Design of winding control electronic cam 4.1 The key to program design lies in the analysis and solutions to the control difficulties of high-speed winding machines. (1) System difficulties. Uneven winding and accumulation occur at the reversal point of the winding machine; spiral marks and unevenness occur at the reversal point of the winding machine; it is impossible to perform slanted winding and odd-even winding. (2) Analysis of difficulties. The uneven winding and accumulation at the reversal point are mainly due to the long processing time of speed instructions of ordinary PLCs. The reversal is affected by the program scanning cycle, there are no synchronous instructions and it is impossible to refresh in real time. At the same time, the servo rigidity parameter and dynamic response speed are also one of the reasons. The appearance of threads at the reversal point is mainly caused by the spiral winding method, which can be solved by using the last half-turn positioning winding. When climbing the slope, the width and thickness of the wire need to be increased by one wire width and wire thickness. Odd-even winding changes the oddness of the number of winding turns in each layer. Both winding methods need to be calculated after each winding. Due to the long calculation time of ordinary small PLCs, it is impossible to perform high-speed slanted winding and odd-even winding. 4.2 Delta Solution As can be seen from the above analysis, the bottleneck of high-speed winding machines lies in high-speed computation and response. The Delta 20PM motion controller, in addition to its logic control CPU, has an independent high-speed computing CPU, enabling direct high-speed computation and response through hardware. The 2-axis synchronous control time is less than 0.5ms, meeting the requirements for high-speed winding. The electronic cam function and application of the Delta 20PM motion controller have been described in previous chapters. Furthermore, programming is very simple and convenient. After setting the cam table using the PMSoft programming software, the electronic cam operation can be completed by directly controlling the corresponding internal registers. Table 2 shows the internal register table for the X-axis winding axis. For example, transmitting different values ​​in the corresponding D1511 can achieve 0 (stop), 1 (forward jog), 2 (reverse jog), 3 (single-speed motion), and 4 (electronic cam motion). Other registers also have their own functions. Table 2. X-axis winding shaft internal register table. The ladder diagram of the X-axis winding shaft is as follows: 5. Conclusion The winding machine control system based on the Delta 20PM electronic cam function has been put into production. The maximum winding speed can reach 2500 r/min, and the quality of the wound products meets user requirements. The Delta 20PM electronic cam function has been successfully applied to high-speed winding machines. The electronic cam function can not only be applied to winding machine control; by changing different control curves, this function is widely used in various high-requirement motion control applications, such as: flying shears in the packaging machine industry, flying saws in the machine tool industry, electronic shaft cutting and overprinting in the printing machine industry, and precision winding in the textile machinery industry, etc.