In the past 20 years, with the development of science and technology, the rise and maturity of advanced manufacturing technology have put forward higher requirements for CNC technology. At present, CNC technology is mainly developing in the following directions:
1) Development towards high speed and high precision
Speed and accuracy are two important indicators of CNC machine tools, which are directly related to the quality and grade of the product, the production cycle of the product and the competitiveness in the market. In terms of machining accuracy, in the past 10 years, the machining accuracy of ordinary CNC machine tools has increased from 10μm to 5μm, and the precision machining center has increased from 3~5μm to 1~1.5μm, and the ultra-precision machining accuracy has begun to enter the nanometer level ( 0.001μm). In terms of processing speed, High-speed feed requires the numerical control system to have a fast calculation speed and a short sampling period. It also requires the numerical control system to have sufficient advance path acceleration (deceleration) optimization preprocessing capabilities (forward processing), and some systems can process 5000 blocks in advance. In order to ensure the processing speed, the high-end CNC system can change the feed rate 2000 to 10000 times per second.
2) Development towards flexibility and functional integration
While increasing the flexibility of a single machine, CNC machine tools are developing towards unit flexibility and systemization. For example, CNC multi-axis machining centers, tool-changing box-changing machining centers and other flexible and efficient processing equipment have appeared; The machine tool composes the Flexible Manufacturing Cell (FMC), Flexible Manufacturing System (FMS), and Flexible Manufacturing Line (FML) of the underlying processing equipment. On modern CNC machine tools, automatic tool changers, automatic worktable changers, etc. have become basic devices. With the development of CNC machine tools in the direction of flexibility, the integration of functions is more reflected in: automatic loading and unloading of workpieces, automatic positioning of workpieces, automatic tool setting, automatic measurement and compensation of workpieces, integration of drilling, turning, boring, milling, and grinding. Integrated "universal processing" and "complete processing" integrating loading, unloading, processing, and measurement.
3) Development towards intelligence With the continuous penetration and development of artificial intelligence in the computer field, numerical control systems are developing in the direction of intelligence. In the new generation of CNC systems, due to the adoption of control mechanisms such as "Evolutionary Computation" (Evolutionary Computation), "Fuzzy System" and "Neural Network", the performance is greatly improved, and the processing process is adaptive Control, automatic load identification, self-generation of process parameters, dynamic compensation of motion parameters, intelligent diagnosis, intelligent monitoring and other functions.
