【作者】 吴昊；

【导师】 杨明； 郑之开；

【作者基本信息】 上海交通大学 ， 控制工程（专业学位）， 2020， 硕士

【摘要】 随动控制是激光切割系统关键技术之一,提高激光随动控制系统的控制品质对于激光切割系统的加工效果、效率起着至关重要的作用。近年来,随着激光技术、设备制造技术等的不断提升,对于激光随动控制系统的要求也越来越高。现有随动控制算法主要采用改进PID(Proportion Integration Differentiation)控制算法,且其局限性也逐步显现,主要体现在系统的鲁棒性、抗扰动能力等方面。自抗扰算法汲取了经典控制算法中以偏差消除偏差和现代控制中状态空间思想,在抗扰能力及鲁棒性上具有很大的优势。因此,本文开展了基于ADRC(Active Disturbance Rejection Control)算法的研究,并将其应用于激光随动控制系统以改进其性能。论文的主要工作及创新点如下:首先,对激光切割随动控制系统需求进行了分析,针对需求设计了激光随动控制整体硬件方案、软件方案和控制算法方案。其中重点分析了激光随动控制系统硬件设计和选型、控制算法方案。激光随动控制系统主要包括上、下位机软件、伺服模块、高度检测模块等。其次,对所采用的基于电容式位移传感器的高度检测方案进行了研究。主要介绍了电容式位移传感器高度检测原理、传感器标定方法、标定结果评价方法、扰动分析。在上述研究的基础上,为了提高高度检测的准确度,设计了基于Kalman滤波器的高度检测方法。基于Kalman滤波器的高度检测方法使用编码器反馈位置和电容传感器检测高度进行数据融合,通过编码器反馈位置来对电容传感器检测高度进行校正,并设计了相应实验验证该方法的有效性。引入Kalman滤波器对电容检测高度进行校正,降低了由于电容边缘效应导致检测板间距和真实板间距偏差,改善了反馈回路的准确性。最后,将自抗扰控制进行改进设计了基于改进自抗扰控制算法的激光随动控制方法。简要介绍了自抗扰控制算法原理。针对自抗扰控制的跟踪微分器中存在不能很好平衡跟踪输出相位滞后和微分提取噪声放大之间的矛盾、参数调试方式复杂问题,将跟踪微分器在零点附近进行等效线性简化并引入输入补偿的思想,设计了复合跟踪微分器。为了提高系统的易用性、降低参数调试的复杂性、降低系统分析的难度采用线性形式扩张状态观测器。同时对控制律的组合方式进行简化。在激光随动控制器性能指标分析的基础上,根据激光随动控制系统的使用场景设计了相关仿真和实测实验验证了改进自抗扰控制算法的性能。仿真和实际测试表明,基于自抗扰控制算法的激光随动控制系统中除了能满足常规的使用场景外,在外部扰动大、反馈信息偏差大等复杂场景下也能够取得很好的控制效果。所设计的基于自抗扰控制器的激光随动控制算法同原有的改进PID控制算法相比较具有更强的鲁棒性、更好的抗扰能力、更广的适用场景、参数调试方便,能够满足激光切割系统对于控制性能的要求。更多还原

【Abstract】 Follow-up control is one of the key technologies of laser cutting system.Improving the control quality of laser follow-up control system plays a vital role in the processing effect and efficiency of laser cutting system.In recent years,with the continuous improvement of laser technology and equipment manufacturing technology,the laser control servo systems are increasingly high requirements.The existing follow-up control algorithm mainly adopts the improved PID control algorithm,and its limitations are gradually emerging.The auto-disturbance-rejection algorithm absorbs the deviations in the classic control algorithm to eliminate the deviations,and at the same time introduces the state-space idea in modern control,which has great advantages in antidisturbance capability and robustness.Therefore,this paper has carried out an algorithm research based on ADRC to improve the performance of laser servo control system.The main work and innovations of the paper are as follows:Firstly,the demand of laser cutting servo control system is analyzed.According to the requirement,the whole hardware scheme,software scheme and control algorithm scheme of laser servo control are designed.The hardware design,selection and control algorithm scheme of laser servo control system are analyzed in detail.The laser cutting servo control system mainly includes upper and lower computer software,servo module,height detection module and so on.Secondly,the height detection scheme based on capacitive displacement sensor is studied.It mainly introduces the principle of capacitive displacement sensor height detection,sensor calibration method,calibration result evaluation method,and disturbance analysis.On the basis of the above research,in order to improve the accuracy of height detection,a height detection method based on Kalman filter is designed.The height detection method based on Kalman filter uses position of encoder and capacitance sensor detection height for data fusion.The detection height of the capacitance sensor is corrected by the feedback position of the encoder,and the corresponding experiment is designed to verify the effectiveness of the method.The Kalman filter is introduced to correct the capacitance detection height,which reduces the deviation between the detection board spacing and the real board spacing due to the capacitance edge effect,and improves the accuracy of the feedback loop.Finally,the auto disturbance rejection control is improved to design the laser servo control method based on the improved auto disturbance rejection control algorithm.The principle of ADRC algorithm is introduced briefly.In order to solve the contradiction between the phase lag of tracking output and the noise amplification of differential extraction,and the complexity of parameter tuning in the tracking differentiator of ADRC,the equivalent linear simplification of tracking differentiator near the zero point and the idea of input compensation are introduced,and the compound tracking differentiator is designed.In order to improve the ease of use of the system,reduce the complexity of parameter tuning,and reduce the complexity of system analysis,linear state expansion state observer is used.Based on the analysis of the performance requirements of the laser servo controller,the relevant simulation and actual measurement experiments are designed according to the usage scenarios of the laser servo control system to verify the performance of the improved auto disturbance rejection control algorithm.Simulation and practical test show that the laser servo control system based on ADRC algorithm can not only meet the normal use scenarios,but also achieve good control effect in complex scenarios such as large external disturbance and large feedback information deviation.Compared with the original improved PID control algorithm,the designed laser servo control algorithm based on auto disturbance rejection controller has stronger robustness,better disturbance rejection ability,wider application scenarios,convenient parameter tuning,and can meet the control performance requirements of laser cutting system.更多还原