基于鲁棒控制的激光切割机光路磁力控制平台特性研究

发布时间：2018-08-29 11:13

【摘要】：传统的激光切割中,要求激光束与辅助气体喷嘴必须同轴,才能保证各方向上加工质量的一致性。研究发现,若激光照射加工材料的焦点和辅助气体喷射焦点的中轴线不同轴时,能够有效的提高工件的加工质量和加工速率。因此需要一种结构紧凑、高速、高精度的驱动器保证实时控制激光束与辅助气体焦点的位置。针对上述驱动器的要求,利用磁力驱动技术的特点,本文在第一代实验样机的基础上,提出一种基于鲁棒控制的激光切割机光路磁力控制平台。在针对第一代实验样机的驱动实验研究中,发现3组永磁弹簧的位置精度对驱动器的轨迹控制影响有较大的影响,因此,提出了优化的改进方案,设计并制造了第二代实验样机。在结构上,采用3组差动式电磁铁提供3自由度的驱动力,采用轴向放置轴向磁化的环形永磁体提供回复力。该微动平台在平动平面内,可以实现X、Y方向的平动和C轴的转动。根据驱动器的结构,用虚位移法建立了磁环永磁体的径向磁力数学模型和差动电磁铁的数学模型,并分别进行了永磁弹簧的有限元分析和实验研究以及电磁铁的理论计算和实验验证,明确了环形永磁体和电磁铁线圈的磁力和位移等参数的关系。建立了激光光路控制驱动器的动力学模型。由于在动力学模型的建立中,进行了差动电磁铁和永磁弹簧在工作点附近的线性化,因此模型并不能准确的表达系统特性,因此在控制上选用鲁棒控制策略,根据系统的特点,选择合适的参数,利用MATLAB鲁棒控制工具箱,设计了混合灵敏度鲁棒控制器,用 MATLAB/Simulink 进行仿真分析。基于 dSPACE1104/controldesk和 MATLAB/Simulink的无缝连接,进行了响应特性、位置特性、转角特性的实验研究。
[Abstract]:In the traditional laser cutting, the laser beam and the auxiliary gas nozzle must be coaxial in order to ensure the consistency of the processing quality. It is found that the machining quality and processing rate of the workpiece can be improved effectively if laser irradiates the focal point of the material and the central axis of the auxiliary gas jet focus. Therefore, a compact, high-speed and high-precision driver is needed to control the position of the laser beam and the auxiliary gas focus in real time. According to the requirements of the above drivers and the characteristics of magnetic drive technology, this paper presents a magnetic control platform of laser cutting machine based on robust control on the basis of the first generation of experimental prototype. In the research of driving experiment of the first generation experimental prototype, it is found that the position precision of three groups of permanent magnet spring has great influence on the locus control of the actuator. The second generation experimental prototype is designed and manufactured. In structure, three sets of differential electromagnets are used to provide 3-DOF driving force, and axial annular magnetized permanent magnets are used to provide the return force. In the translational plane, the platform can realize the translation of XY direction and the rotation of the C-axis. According to the structure of the actuator, the mathematical model of radial magnetic force of permanent magnet and the mathematical model of differential electromagnet are established by virtual displacement method. The finite element analysis and experimental study of the permanent magnet spring and the theoretical calculation and experimental verification of the electromagnet are carried out respectively. The relationship between the magnetic force and the displacement of the ring permanent magnet and the electromagnet coil is clarified. The dynamic model of laser optical path control driver is established. Because the differential electromagnet and permanent magnet spring are linearized near the operating point in the establishment of the dynamic model, the model can not express the characteristics of the system accurately, so the robust control strategy is chosen in the control, according to the characteristics of the system. The mixed sensitivity robust controller is designed by using the MATLAB robust control toolbox and the appropriate parameters are selected. The simulation analysis is carried out with MATLAB/Simulink. Based on the seamless connection of dSPACE1104/controldesk and MATLAB/Simulink, the characteristics of response, position and angle are studied experimentally.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG485

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