为了扩大原子力显微镜(Atomic Force Microscope,AFM)使用范围,研制了一套大范围高速AFM系统。针对大范围高速扫描时Z方向控制问题,提出了前馈反馈混合控制方法。前馈控制包括自动调平前馈和基于前一行扫描前馈,前者通过多线扫描确定样...为了扩大原子力显微镜(Atomic Force Microscope,AFM)使用范围,研制了一套大范围高速AFM系统。针对大范围高速扫描时Z方向控制问题,提出了前馈反馈混合控制方法。前馈控制包括自动调平前馈和基于前一行扫描前馈,前者通过多线扫描确定样品倾斜位置,将所有扫描点的倾斜位移差用函数式表达,然后将其换算为Z向驱动电压后驱动下扫描器运动;后者利用前一行扫描高度数据作为当前行Z向扫描器驱动的参考输入。反馈控制为在普通比例-积分(PI)控制基础上改进的动态P参数PI控制,P参数设置与误差大小有关。实验结果表明:采用本控制方法最大控制误差由40.17nm减小为6.01nm,误差均方根值由22.85nm减小为2.01nm,明显抑制了误差信号,提高了Z向控制效果,获得了更精确的高度图像。展开更多
In this article, state feedback predictive controller for hybrid system via parametric programming is proposed. First, mixed logic dynamic （MLD） modeling mechanism for hybrid system is analyzed, which has a distingu...In this article, state feedback predictive controller for hybrid system via parametric programming is proposed. First, mixed logic dynamic （MLD） modeling mechanism for hybrid system is analyzed, which has a distinguished advantage to deal with the logic rules and constraints of a plant. Model predictive control algorithm with moving horizon state estimator （MHE） is presented. The estimator is adopted to estimate the current state of the plant with process disturbance and measurement noise, and the state estimated are utilized in the predictive controller for both regulation and tracking problems of the hybrid system based on MLD model. Off-line parametric programming is adopted and then on-line mixed integer programming problem can be treated as the parameter programming with estimated state as the parameters. A three tank system is used for computer simulation, results show that the proposed MHE based predictive control via parametric programming is effective for hybrid system with model/olant mismatch, and has a potential for the engineering applications.展开更多
文摘为了扩大原子力显微镜(Atomic Force Microscope,AFM)使用范围,研制了一套大范围高速AFM系统。针对大范围高速扫描时Z方向控制问题,提出了前馈反馈混合控制方法。前馈控制包括自动调平前馈和基于前一行扫描前馈,前者通过多线扫描确定样品倾斜位置,将所有扫描点的倾斜位移差用函数式表达,然后将其换算为Z向驱动电压后驱动下扫描器运动;后者利用前一行扫描高度数据作为当前行Z向扫描器驱动的参考输入。反馈控制为在普通比例-积分(PI)控制基础上改进的动态P参数PI控制,P参数设置与误差大小有关。实验结果表明:采用本控制方法最大控制误差由40.17nm减小为6.01nm,误差均方根值由22.85nm减小为2.01nm,明显抑制了误差信号,提高了Z向控制效果,获得了更精确的高度图像。
文摘In this article, state feedback predictive controller for hybrid system via parametric programming is proposed. First, mixed logic dynamic （MLD） modeling mechanism for hybrid system is analyzed, which has a distinguished advantage to deal with the logic rules and constraints of a plant. Model predictive control algorithm with moving horizon state estimator （MHE） is presented. The estimator is adopted to estimate the current state of the plant with process disturbance and measurement noise, and the state estimated are utilized in the predictive controller for both regulation and tracking problems of the hybrid system based on MLD model. Off-line parametric programming is adopted and then on-line mixed integer programming problem can be treated as the parameter programming with estimated state as the parameters. A three tank system is used for computer simulation, results show that the proposed MHE based predictive control via parametric programming is effective for hybrid system with model/olant mismatch, and has a potential for the engineering applications.
