With the development of China's mold industry, the processing precision, surface quality and processing efficiency required for mold processing are also getting higher and higher. To process high-quality molds, it is necessary to have CNC machine tools that are suitable for mold processing characteristics and have high efficiency. Excellent high-speed processing function, five-axis linkage processing function and user-friendly human-machine interface are the goals pursued by this type of machine tool. To meet the high performance requirements, the machine tool needs to start from the following aspects: (1) Machine tool mechanical design: high mechanical rigidity and low mass of moving parts; (2) Feed design: high acceleration capability and large speed control range capability; (3) Spindle system design: high axis speed, low non-uniformity and good speed stability; (4) Cutting tools: suitable for high-speed processing requirements; (5) CNC system and measurement feedback, etc. Heidenhain is a multinational group company with more than 100 years of history specializing in the production of high-precision measuring elements and CNC systems. Its high-performance CNC systems and measurement feedback elements have been widely used in the fields of mold processing and high-precision processing. Figure 1 shows the complete set of CNC systems and measurement feedback elements provided by Heidenhain for use on high-performance machine tools. This article provides a brief introduction to Heidenhain's iTNC 530 CNC system, which is widely recognized in the mold industry, starting with its high-speed machining characteristics. [align=center]Heidenhain iTNC 530 Control System[/align] Hardware Design of the iTNC 530 System The quality of the hardware design determines whether the control system is suitable for high-speed, high-precision, and high-surface-quality machining. The iTNC 530 adopts a brand-new microprocessor architecture with very powerful computing capabilities. The iTNC 530 control system can control up to 12 axes. The controller itself consists of two parts: the host unit (MC) and the control unit (CC). The host unit (MC) uses a Pentium III-800 chip and a 133MHz bus frequency, ensuring all calculations, screen displays, and data communication. All real-time tasks of the iTNC530 are completed under its own developed real-time operating system (HEROS). Heidenhain also provides a host computer with dual processors, which can guarantee the system's real-time computing and stability performance while meeting users' needs for Windows applications. Meanwhile, the main unit's storage is achieved through a 30GB hard drive, providing ample storage space for complex mold processing. The main unit features various data communication interfaces (Ethernet/RS232/RS422/USB, etc.), and its Fast Ethernet communication interface can transmit program data at a rate of 100Mbit/s. The latest design of the control unit (CC) integrates all servo control loops (position loop/speed loop/current loop) of the control system, with all servo calculations performed in the DSP (Digital Signal Processor). Therefore, feedback from the measuring elements is integrated into the control unit, including position and speed feedback. Its advantages include: ensuring fast and real-time servo calculations, reducing the cycle time of each servo loop, reducing communication delays between loops, achieving high gain in the position loop, enabling high-speed and high-surface-quality machining, and providing excellent control over direct drives (linear motors and torque motors). Drive support: Heidenhain can provide a complete iTNC 530 CNC system, including inverter modules, power supply modules, servo motors, and spindle motors, as needed. Meanwhile, the Heidenhain CNC system also has excellent openness, and can connect to third-party frequency converters or motors to form a complete digital system. Due to the special control unit design of the iTNC 530, all servo motion control is implemented in the control unit, and its output is a digital PWM signal. Therefore, the subsequent frequency converter mainly has operational amplification function. Good servo control and high-speed control capability For complex curved surfaces, if high-speed, high-precision and high-surface-quality machining is to be achieved, the control system software must also have good servo performance and high-speed control capability on the basis of good hardware. Figure 2 shows a typical part processed by a high-speed machining tool. The following are some characteristics required for the control system of a high-performance machining tool: [align=center] Example of part processed by a high-speed machining tool[/align] (1) Full digital drive technology With the support of powerful hardware, the iTNC 530 adopts full digital technology. Its position controller, speed controller and current controller are all digitally controlled. Digital motor control technology can achieve very high feed rates. When interpolating up to 5 axes simultaneously, the iTNC 530 can still achieve the required cutting speed of a CNC spindle with a speed of up to 40,000 rpm. (2) Fast program segment processing speed Advanced feedforward servo technology increasingly places program segment processing in the background. Even so, for some machining tasks, fast program segment processing is still the best way to obtain ideal machining results, such as high-precision contour machining. The iTNC 530 has ideal program segment processing speed performance, achieving short program segment processing time (0.5ms) and short control loop cycles (position loop cycle is 100µs) as well as various interpolations (straight line/circular arc/spiral/spline). (3) High contour accuracy The iTNC 530 also has a 1024-segment (which can be set through machine tool parameters) pre-read function. The "pre-read" function can predict future changes in direction to adjust the motion speed to meet the requirements of the programmed surface. When the tool cuts into the workpiece, the iTNC 530 can automatically reduce the feed rate as needed. Therefore, when programming the feed rate, you only need to use the highest machining speed. The iTNC 530 can automatically adjust the actual speed according to the workpiece contour, saving machining time. The built-in filter can significantly suppress the inherent frequency of each machine tool while ensuring the required surface accuracy. At the same time, the iTNC 530 can realize various error compensations, including linear and nonlinear axis errors, backlash, sharp angles of circumferential motion, thermal expansion, and viscous friction. (4) Achieving high-speed machining while ensuring accuracy High-speed cutting represents fast and efficient contour milling. The CNC system must be able to quickly transmit large amounts of data, allow efficient editing of long programs, and ensure that the machined workpiece has an ideal contour. These are all advantages of the iTNC 530. In addition to the NC program, the end user can also specify the accuracy of contour machining through a fixed cycle. Just input the maximum allowable deviation from the ideal contour to the CNC system using the cycle. The iTNC 530 will automatically adjust the machining according to the required deviation and it can ensure that the contour is not damaged. (5) Acceleration Control (Jerk) To ensure a machine tool has good acceleration and deceleration capabilities, it is essential to maintain reasonable acceleration. If the acceleration is too large (abrupt), acceleration can be achieved in a short time, but it will also cause machine tool vibration, resulting in stripes on the machined surface and reducing surface finish. If the acceleration is too small, high surface quality can be achieved, but it is difficult to achieve fast acceleration. Therefore, ensuring high speed and high surface quality is very important. The iTNC 530 system achieves the above functions by limiting the acceleration value and using a filter to smooth the acceleration. By using this function, machine tool vibration caused by abrupt acceleration during machining can be reduced to achieve high surface quality machining, while also achieving good acceleration and deceleration performance of the machine tool. (6) Nominal Position Filter After the control system completes the interpolation function, it generates a nominal position value to provide to the subsequent position loop. As we all know, achieving high speed, high precision, and high surface quality requirements is related to many factors, especially the dynamic performance of the machine tool itself. The iTNC 530 system offers different types of built-in nominal position filters, such as a single filter (Standard filter), an expanded filter, and a high-speed filter (HSC filter). The system can determine which filter to use based on different user needs and the dynamic performance of the machine tool itself, which can be achieved by setting different parameters. Of course, to fully utilize the dynamic performance of the machine tool, Heidenhain provides a series of debugging tools to facilitate debugging for various machine tool manufacturers. Figure 3 shows an example of high-speed contour machining under the control of the iTNC 530 system. [align=center]Example of High-Speed ​​Contour Machining Process[/align] Conclusion This article briefly introduces the high-speed characteristics of Heidenhain's iTNC 530 system. All the features described are standard configurations in the iTNC 530 CNC system. Subsequent articles will introduce features related to five-axis/multi-axis characteristics, user-friendly human-machine interface features, and the newly developed dynamic collision monitoring function.