【作者】 刘能锋；

【导师】 王昕；

【作者基本信息】 哈尔滨工业大学 ， 机械电子工程， 2009， 硕士

【摘要】 随着大规模集成电路,精密加工设备,计算机硬盘等高新技术的飞速发展,对数控系统加工速度及加工精度的要求也越来越高,所以在加工速度不断提高的同时,跟踪误差的精度问题已经成为亟待研究和解决的问题之一。本文在分析误差来源的基础上,结合NURBS曲线的特点,设计了多轴协调跟踪控制系统。控制系统主要分为提高单轴跟踪精度和双轴轮廓精度两个部分,在提高单轴跟踪精度上,运用基于模型扰动抑制器来处理外部负载产生的干扰问题,并增加系统的强健性和稳定性。在提高单轴跟踪精度的同时间接提高轮廓精度。在提高轮廓精度上,针对NURBS等多种曲线运用带实时轮廓误差估测的交叉偶和控制算法、位置误差跟踪补偿算法及NURBS曲线速度规划实现NURBS曲线轮廓的跟踪任务,增加各轴间的协调性以降低轮廓误差,提高跟踪精度。文中首先对X-Y实验平台进行系统辨识,建立数学模型,并归纳不同曲线轮廓误差的计算方法。其次,在NURBS曲线插补中运用快速德布尔算法,对进给速度进行合理规划。然后为提高跟踪精度,根据误差来源的分析,设计了多轴协调跟踪控制器。其中,为保证系统的稳定性,还对控制器进行了稳定性分析。经过计算机的仿真和实验验证,表明本文提出的多轴协调跟踪控制系统能很好的改善轮廓精度,提高跟踪性能。更多还原

【Abstract】 With the rapid development of high technology such as the large-scale integrated circuits, precision processing equipment, computer hard drivers and so on, the requirements of high-speed and high-precision processing in CNC system is increasing. Therefore, the accuracy of the tracking error and processing speed are required to be improved.Based on the analysis of the error source and the characteristics of NURBS curve, the multi-axis coordinate tracking control system is designed in this paper, The control system mainly includes the two parts of functions: the reduction of single-axis position error and the contour error in biaxial system. In tracking error, in order to eliminate the external disturbance, model-based disturbance attenuation is employed to enhance the robust and stability of the system. The reduction of position error can improve the contour accuracy indirectly. In contour error, combining with the feedrate regulator of NURBS curve, the cross-coupled control with real-time contour error estimator and position error position compensator (PEC) are applied in this research to improve the multi-axis coordination and complete the tracking task.Firstly, system identification of X-Y table is carried out, and the mathematic model is established, then the contour error calculation methods is introduced in the following. Secondly, the fast de-boor method is employed in NURBS interpolation. The feedrate is regulated by two stages. Finally the multi-axis coordination control system is designed on basis of machining error and the stability of control system is also analyzed. The proposed multi-axis coordinate tracking control system can improve the contour accuracy and tracking performance effectively by simulation and experimental results.更多还原