Analysis on the detection technology of laser cutting quality

Laser processing technology is a composite advanced manufacturing technology that integrates disciplines such as optics, mechanics, electricity, material processing and testing. It is combined with modern numerical control technology to form high-efficiency automatic processing equipment, which can break through many technical bottlenecks that cannot be achieved by traditional manufacturing methods. It is used in energy, transportation, iron and steel metallurgy, ship and automobile manufacturing, electronic and electrical industry, aerospace and other national economic pillars. The industry has played an irreplaceable role.

Automobiles, ships, aviation, aerospace, steel, energy and other Chinese industries all urgently need laser cutting equipment, especially high-end equipment, so it is very important to improve the manufacturing level of laser cutting equipment in my country. It can not only meet the needs of the domestic market, break the technological monopoly of foreign countries in this field, but also promote the progress of my country's laser cutting technology. Achieving higher speed, high precision and intelligent laser cutting will be the goal of the development of CNC machine tool cutting machine technology.

The use of laser cutting machines has been used in thousands of households, but the quality sometimes varies from good to bad, so how to distinguish its quality?

The quality of the laser cutting machine is affected by various factors. In order to obtain the ideal cutting quality, each cutting parameter is limited to a narrow range. It is necessary to rely on repeated experiments to explore reasonable conditions under different conditions. Cutting parameters are not only time-consuming and labor-intensive, but also unable to respond to disturbance factors in the cutting process. How to quickly find the optimal cutting parameters under different cutting conditions and keep them stable during the cutting process is particularly important. Therefore, it is necessary to study on-line monitoring and real-time control of laser cutting quality.

The most important indicator of high-quality laser cutting is that the roughness of the cut surface without cutting defects is small, so the target of real-time monitoring should be able to identify cutting defects and monitor the information that reflects the roughness of the cut surface. Obtaining the roughness information is the most important and the most difficult.

In the aspect of monitoring the roughness of the cutting surface, an important research result is to find that the main frequency of the pulsation spectrum of the optical radiation signal at the cutting front is equal to the frequency of the cutting fringe of the cutting surface, and the frequency of the cutting fringe is related to the roughness. In this way, the radiation signal monitored by the photoelectric tube is related to the roughness of the cut surface. The characteristic of this method is that the monitoring equipment and signal processing system are relatively simple, and the monitoring and processing speed is fast. However, the shortcomings of this method are:

Further research shows that the main frequency of the cutting-edge optical radiation signal is The consistency of the fringe frequency on the cutting surface is limited to the range of the smaller cutting speed. When the cutting speed is greater than a certain cutting speed, the main frequency of the signal disappears, and no information related to the cutting fringe can be found.

Therefore, only relying on the light radiation intensity signal of the cutting front has great limitations, and it is difficult to obtain valuable cutting surface roughness information, especially near the lower edge roughness information, at a normal cutting speed. The visual sensor is used to monitor the surface and the spark cluster.