A composite algorithm combined with fuzzy proportional-integral-derivative (PID) control and acceleration closed-loop control is proposed to address the defects of slow response speed, strong oscillation, and long adjustment time of the current height following control system for a laser cutting head. The fuzzy PID control can satisfy the different requirements for the control parameters in each stage of the height follow-up adjustment process for the laser cutting head via the adaptive adjustment of the PID parameters. Accordingly, the height following error can be attenuated to the set positioning accuracy range. The acceleration closed-loop control can improve the acceleration and deceleration performance of the system through the positive and negative feedback regulation of the motion acceleration of the laser cutting head to achieve high-speed servo. An experimental bench of height follow-up control system for laser fabrication is developed to verify the effectiveness of the algorithm. Through experimental verification, compared with the conventional digital PID incremental algorithm, this composite control algorithm can accelerate the response speed of height follow-up control system for the laser cutting head, improve the dynamic performance of the system, and realize fast and precise servo control of laser cutting head height under the premise of ensuring positioning accuracy. The proposed algorithm is expected to lay a foundation for the development of the new intelligent laser processing system.

1. [1] C. Chen et al., “Relationship between temperature at cut front edge and kerf quality in fiber laser cutting of Al-Cu aluminum alloy,” Int. J. of Machine Tools and Manufacture, Vol.109, pp. 58-64, 2016.
2. [2] Y. Hara et al., “Fabrication of Stainless Steel Microneedle with Laser-Cut Sharp Tip and its Penetration and Blood Sampling Performance,” Int. J. Automation Technol., Vol.10, No.6, pp. 950-957, 2016.
3. [3] Q. Gong et al., “Evolution of Chip-Deformation Mechanisms with Increasing Temperature in Laser-Assisted Microcutting of Amorphous Alloy,” Int. J. Automation Technol., Vol.14, No.4, pp. 568-574, 2020.
4. [4] B. Denkena et al., “Advanced Control Strategies for Active Vibration Suppression in Laser Cutting Machines,” Int. J. Automation Technol., Vol.9, No.4, pp. 425-435, 2015.
5. [5] T. Arai, “Technical review of laser materials processing in Japan,” Int. J. Automation Technol., Vol.10, No.6, pp. 854-862, 2016.
6. [6] Y. Morimoto et al., “Effect of high-frequency orbital and vertical oscillations of the laser focus position on the quality of the cut surface in a thick plate by laser beam machining,” Precision Engineering, Vol.40, pp. 112-123, 2015.
7. [7] B. X. Cao et al., “Automatic real-time focus control system for laser processing using dynamic focusing optical system,” Optics Express, Vol.25, No.23, pp. 28427-28441, 2017.
8. [8] B. Zhang et al., “Back-Stepping Sliding Mode Control of Laser Cutting Permanent Magnet Linear Servo Control System,” Trans. of China Electrotechnical Society, Vol.33, No.3, pp. 642-651, 2018 (in Chinese).
9. [9] G. Cerwenka et al., “Focus shift control of a novel 30 kW laser remote scanner for large-scale industrial sheet and plate metal applications,” Procedia CIRP, Vol.94, pp. 817-822, 2020.
10. [10] B. Zhang et al., “Application of composite sliding mode control on motion platform of PMLSM precision laser cutting,” Optics and Precision Engineering, Vol.25, No.1, pp. 84-92, 2017 (in Chinese).
11. [11] S. Wei et al., “Design of Z-Axis Position Servo Control System for Laser Processing Based on Fuzzy PID Control,” Proc. of the 12th Int. Conf. on Intelligent Computation Technology and Automation (ICICTA), pp. 592-600, 2019.
12. [12] S. Fu et al., “The geometry errors analysis of laser cutting head,” Key Engineering Materials, Vol.621, pp. 94-100, 2014.
13. [13] Y. Zhang, “The laser focus position control system based on motion controller,” Applied Mechanics and Materials, Vols.644-650, pp. 636-638, 2014.
14. [14] R. Zhang et al., “Closed-Loop Control of Laser Engineered Net Shaping of Unequal-Height Parts,” Chinese J. of Lasers, Vol.45, No.3, pp. 215-221, 2018 (in Chinese).
15. [15] S. Xu et al., “A fuzzy control scheme for deployment of space tethered system with tension constraint,” Aerospace Science and Technology, Vol.106, 106143, 2020.
16. [16] E. A. Muravyova and E. H. Atangulova, “Adaptive Fuzzy Control for Rectification Process of Recycled Solvent,” Proc. of Int. Multi-Conf. on Industrial Engineering and Modern Technologies, pp. 1-6, 2020.
17. [17] J. Li, “Design and Simulation of DC Motor Controller Based on the Fuzzy Control,” Proc. of the 5th Int. Workshop on Advanced Algorithms and Control Engineering, Vol.1861, 012121, 2021.
18. [18] C. Li et al., “Fuzzy pid control of electromechanical actuator system,” J. of Physics: Conf. Series, Vol.1721, 012052, 2020.
19. [19] N. D. Phu et al., “A New Fuzzy PID Control System Based on Fuzzy PID Controller and Fuzzy Control Process,” Int. J. of Fuzzy Systems, Vol.22, No.7, pp. 2163-2187, 2020.
20. [20] A. Eltayeb et al., “Trajectory Tracking for the Quadcopter UAV utilizing Fuzzy PID Control Approach,” Proc. of Int. Conf. on Computer, Control, Electrical, and Electronics Engineering (ICCCEEE), pp. 1-6, 2020.