The Design And Implementation Of A Focusing And Alignment System Based On Multiple Laser Beams

Laser beams, which possess a lot of good properties, such as directional luminescence, good brightness performance, and large amount of energy, have been broadly applied in many subjects, including optics, mechanics, electronics and etc. Influenced by the development level of technology, laser devices which are capable of producing high power while are portable and reliable still remain in the developmental phase, which restricts its application fields to some extent. In order to obtain higher power, a feasible solution is to gather the energy from multiple laser beams. This thesis researches on design and implementation of a focusing and alignment system based on multiple laser beams. This system uses a physical frame to carry multiple laser devices. Operated by the corresponding three-dimension linear stage, each device can move independently, which makes it be able to achieve the goal of direction alignment changing and focal point adjusting. This thesis focuses on three aspects, the process of hardware selection, the methods of control system design, and the implement of software. It provides the research value on the multi-stage synergy control field.First of all, the overall design of the system is given in this thesis. To meet the 0.022 mm static positional accuracy and 0.11 mm dynamic tracking error, the requirement analysis of hardware is given. To satisfy the 50 Hz control period and manual & automatic control function, the principle of software development environment choosing and function implementation conceive is given.Furthermore, we select the hardware and verify its performance. According to structural constraints and performance indicators of the system, we have selected the VP-25 XA high-performance linear stages and PM-012 linear stages as actuators of the alignment stages, and the LAC320 voice coil motors as actuators of the focusing stages. By checking the parameters of each actuator, we can ensure that the actuators can meet the static and dynamic performance indicators, which makes it possible for the overall system implementation.Moreover, in order to meet the performance indicators of location tracking of focusing stages, we have designed the control system of the LAC320 voice coil motors. We have studied on the dual-loop control strategy-the speed loop and position loop-as well as PID control methods. In the end, the step response curves and the tracking performance curves are given.Finally, the software is designed. Its main body is written using C++ language while its information storage function is written using xml language. We have designed the interfaces using MFC class library while have accessed the xml files by libxml2.dll class library. Meanwhile, we use AC algorithm to improve the performance of data analysis module as well as the memory space utilization ratio. We use HASH table to reduce the time cost of automatic focal point adjusting time. We use hill climbing algorithm combined with bisection method to achieve the automatic focal point adjusting function and improve its performance. The experiments show that the required functions are all achieved and the algorithms are effective.This thesis tends to give a complete system design process. It describes the solutions of every parts in detail, and tests the stability and correctness of every part independently. The test results demonstrate that the research on design and implementation of a focusing and alignment system based on multiple laser beams is meaningful in practice and the solutions described in the thesis have met the design requirements.