| High power TEA CO2 laser is a pulsed gas laser with laser wavelength of 10.6μm, and is a kind of large equipment integrating optics, mechanics and electricity, which has wide application in industry, scientific research and military affairs. With the development of TEA CO2 laser itself and its application, the complexity of the system becomes higher and higher, so as for the control system, we propose much higher requirement. At present, the control system adopting single chip and programmable controller has shortcomings in the aspects of controlling function, simple data operation and slow operation speed, and signal treatment respectively. Therefore, it can not satisfy the growing application and requirements. While DSP has the function of valuable control and massive data high-speed operation, meanwhile, it also has the function of small size, high reliability and excellent system expansibility, so this paper proposes to adopt DSP to design high power TEA CO2 laser control system.The core duty of high power TEA CO2 laser system is pulsed discharge process of high voltage and heavy current. During this process, strong electromagnetic interference and destructive effect to the internal electrical system laser system will be produced, thus the control system must have the function of strong anti-interference and high reliability. This paper carries out the general design for high power TEA CO2 laser control system, design for basic hardware and software, design for electromagnetic compatibility of the hardware, and design for rational purify, and also carries out the system adjustment and the test of electromagnetic compatibility. The test result verifies that this paper designed control system has stable performance and strong anti-interference capability. Comparing to the control system using the past single chip or programmable controller, the control system adopting DSP as the core has improved in the aspect of control function, operation speed and etc. to a large extentThis paper mainly carries out the following five works:1. General design for the high power TEA CO2 laser control system;2. Design for basic hardware and design for electromagnetic compatibility;3. Design for basic software and design for rational purify;4. System adjustment;5. Performance comparison. The following is the introduction for respectively.1. General design for the high power TEA CO2 laser control system According to the requirements of the system performance, high performance DSP F2812 from TI Company as controlling core is used, and general design for the high power TEA CO2 laser control system is carried out.2. Design for basic hardware and design for electromagnetic compatibility⑴Carrying out the design for ADC circuit, I/O interface circuit, keyboard circuit, liquid crystal display circuit, serial communication circuit, CPLD circuit, power supply circuit and level switch circuit.⑵Adopting CPLD to make I/O expansion, realizing the design of input, output and logistic circuit, simplifying the circuit, shortening PCB board, and improving the flexibility and anti-interference ability of the circuit.⑶Carrying out the analysis on electromagnetic compatibility, according to the principles of electromagnetic compatibility to carry on integral layout and wiring, adopting the measure of screening, wave filtering and isolation, and carry on the design for electromagnetic compatibility of PCB board, so that the hardware system will have more strong anti-interference ability.3. Design for basic software and design for rational purifySoftware requirement analysis is made according to the method of software industrialization, and the software is designed adopting user-defined modularized thought with stepwise refinement. The structure drawing of the main procedure, flow chart of the main procedure, modularized structure drawing, flow chart of partial branch modules, DSP software design and its engineering document constitution, and a CPLD circuit design code are introduced. Modularized design will make the procedure have strong readability and easy programming, which is convenient for adjustment and prone to expand and maintain. Carrying out the design for rational purify, including three methods of input debugging, voting debugging and output supervision improving the reliability of the system.4. System adjustmentCarrying out three kinds of works including hardware detection, system electrification adjustment and electromagnetic compatibility test of the control system mainboard. The real drawing of control system mainboard, CPLD code structure and its compiling phase drawing, pulse output emulational waveform and etc are given. The adjustment results show that the system realizes the controlling function, the high power TEA CO2 laser has stable work environment and strong anti-interference.5. Performance comparison Comparing to the control system adopting the past single chip or programmable controller, the control system using DSP as the core has improved in a large extent in the aspect of operation speed, communication speed, data processing and expandability of the system.At present, the foreign countries researching on the same type of high power TEA CO2 laser system include Canada, France, Russia, Japan, Germany, and etc.; The major domestic units researching on such system include Changchun Institute of Optics, Fine Mechanics and Physics of Chinese Academy of Sciences, Institute of Electronics of Chinese Academy of Sciences, the No. 12 Research Institute of China Electronics Technology Group Cooperation, Huazhong University of Science and Technology and etc. The most important sign of levels of TEA CO2 laser is the average output power level, several kilowatts TEA CO2 laser is successfully developed in 2006, which shows that China has reached advanced world level.The main advantages of TEA CO2 laser are large output power and high efficiency. Its energy conversion efficiency is as high as 20%～25%; output power can reach several kilowatts; output energy of pulse can reach 103J; especially its output wavelength is just in atmospheric window, and the harm to eyes is less than that of visible light and 1.06μm infrared light. Therefore, it has the special applications that other lasers can not replace, such as communication, radar, laser weapon, and etc., especially the hot international research topic in recent years—laser propellant uses the laser as the first choice.TEA CO2 laser system is constructed complicatedly, there are seven sub-systems. Each sub-system has great differences in aspect of power, electric level and control mode. Among those sub-systems, six of them are coordinated by control sub-system as real-time controlling of the laser. Thus the control system is much complex. Besides the basic functions, the control system designed by this paper also has the functions of reliable and timely protection for personnel safety and equipment safety. In addition, the protective functions contain power supply monitoring, excess current, excess voltage, excess atmospheric pressure, emission frequency monitoring, temperature monitoring, launching time monitoring, electromagnetic interference restrain and etc.Adopting DSP as the core of high power TEA CO2 laser control system, there is no such report both at home and abroad at present. Its success will update current single chip or programmable controller system, improves the TEA CO2 laser system itself and its application level in a large extent, and bring significant effect to the research on high power TEA CO2 laser for our country. |
PDF Full Text Request