Prior to the 1970s, research focused on pulsed laser welding (PW), since high-power continuous wave (CW) lasers had not yet been developed. Most of the early laser welding research experiments used ruby pulse lasers. The typical peak output power Pm of 1ms pulse is about 5KW, the pulse energy is 1~5J, and the pulse frequency is less than or equal to 1 Hz. At that time, although higher pulse energy could be used, the average output power P of these lasers was quite low, which was mainly determined by the low working efficiency of the lasers and the excited properties of the luminescent substances. Due to its high average power, the laser became the preferred equipment for spot welding and seam welding soon after it appeared. The real laser seam welding can be realized.
Current Situation and Prospect of Welding Automation Technology
With the increasing maturity of digital technology, the representative office's digital welding machine and digital control technology have entered the market steadily. National large-scale basic projects such as the Three Gorges Project, the West-East Gas Pipeline Project, aerospace engineering, and ship engineering have effectively promoted the development and progress of advanced welding, especially welding automation technology. The manufacturing of automobiles and parts has ever-changing requirements for the automation of welding. my country's welding industry is gradually moving towards "high efficiency, automation and intelligence". The welding automation rate in our country is less than 30%, far from the 80% in developed industrial countries. Since the end of the 20th century, the country has gradually promoted the basic welding method of automatic welding in various industries - gas shielded welding, to replace the traditional manual arc welding, and has achieved initial results. It can be predicted that in the future, domestic automatic welding technology will develop at an unprecedented speed.
Current status of high-efficiency and automatic welding technology
In the 1990s, my country's welding industry took the realization of the mechanization and automation of the welding process as a strategic goal, and it has been put into practice in the development of science and technology in various industries. It is developing welding production automation, researching and developing welding production lines and flexible manufacturing technologies, and developing applications. Computer-aided design and manufacturing; flux cored wire increased from 2% to 20%; submerged arc welding consumables will also continue to grow at the level of 10%. Among them, the growth rate of flux-cored wire has increased significantly, and will surpass solid-core wire in the next 20 years, and will eventually become the leading product in welding centers.
Prospect of Welding Automation Technology
The development of electronic technology, computer microelectronics and automation technology has promoted the development of welding automation technology. In particular, the introduction of unit technologies such as numerical control technology, flexible manufacturing technology and information processing technology has promoted the revolutionary development of welding automation technology.
(1) The intelligence of the welding process control system is one of the core issues of welding automation, and it is also an important direction for our future research. We should conduct research on optimal control methods, including linear and various nonlinear controls. The most representative ones are the fuzzy control, neural network control, and expert system research of the welding process.
(2) Welding flexibility technology is also the content of our research. In future research, we will organically combine various optical, mechanical and electrical technologies with welding technology to achieve precise and flexible welding. Transforming traditional welding equipment with microelectronic technology is the fundamental way to improve the level of welding automation. Matching numerical control technology with various welding machinery and equipment to improve its flexibility level is one of our current research directions; in addition, the combination of welding robots and expert systems can realize automatic path planning, automatic trajectory correction, automatic control of penetration depth, etc. Function is the focus of our research.
(3) The integration of welding control system is the integration of people and technology and the integration of welding technology and information technology. The information flow and material flow in the integrated system are its important components, promoting their organic combination can greatly reduce the amount of information and the requirements for real-time control. Attention should be paid to giving full play to the response and judgment ability of human beings in control and temporary processing, establishing a friendly interface between human and machine, and making the human and automatic systems harmonious and unified, which are the factors that cannot be underestimated in the integrated system.
(4) Improving the reliability, quality stability and control of the welding power source, as well as the excellent dynamics, are also the subjects we focus on. Develop and develop high-performance welding machines that can adjust the arc movement, wire feeding and welding torch attitude, can detect the beginning of the weld slope, temperature field, molten pool state, and penetration, and provide welding specification parameters in a timely manner, and actively develop computers for the welding process analog technology. An important aspect of welding automation is to make welding technology evolve from "art" to "science". The first decade of this century will be a favorable period for the rapid development of the welding industry. Our welding workers have a long way to go, and we must establish the determination to overcome difficulties. Seize the opportunity and work hard to improve the level of welding automation in our country.