Learning control for gradually varying references in iteration domain was considered in this research, and a composite iterative learning control strategy was proposed to enable a plant to track unknown iteration-depe...Learning control for gradually varying references in iteration domain was considered in this research, and a composite iterative learning control strategy was proposed to enable a plant to track unknown iteration-dependent trajectories. Specifically, by decoupling the current reference into the desired trajectory of the last trial and a disturbance signal with small magnitude, the learning and feedback parts were designed respectively to ensure fine tracking performance. After some theoretical analysis, the judging condition on whether the composite iterative learning control approach achieves better control results than pure feedback contro! was obtained for varying references. The convergence property of the closed-loop system was rigorously studied and the saturation problem was also addressed in the controller. The designed composite iterative learning control strategy is successfully employed in an atomic force microscope system, with both simulation and experimental results clearly demonstrating its superior performance.展开更多
This paper presents a novel design method of force rebalance control for the sense mode of micromachined vibratory gyroscopes.Specific theoretical deductions are performed to identify a precise linear model of the ope...This paper presents a novel design method of force rebalance control for the sense mode of micromachined vibratory gyroscopes.Specific theoretical deductions are performed to identify a precise linear model of the open loop system of the sense mode,which is crucial for the PI controller design.The frequency responses obtained by experimental tests agree well with those calculated with the theoretical model,indicating the accuracy of the theoretical analyses.Experimental results demonstrate that the bandwidth of the closed loop is extended to 94.8 Hz from 2.3 Hz in the open loop and the quadrature signal is suppressed by about 64 dBV in the closed loop system.The overshoot and stable time in the step response of the closed loop system are measured to be about 15% and 35 ms,respectively.The mode-splitting gyroscope with the closed loop controlled sense mode achieves a scale factor of 41.0 mV/deg/s with nonlinearity of 0.09% and asymmetry of 1%,and a bias instability of 4.0 °/h with angle random walk of 0.171 deg/h1/2.展开更多
基金Projects(61127006,61325017)supported by the National Natural Science Foundation of China
文摘Learning control for gradually varying references in iteration domain was considered in this research, and a composite iterative learning control strategy was proposed to enable a plant to track unknown iteration-dependent trajectories. Specifically, by decoupling the current reference into the desired trajectory of the last trial and a disturbance signal with small magnitude, the learning and feedback parts were designed respectively to ensure fine tracking performance. After some theoretical analysis, the judging condition on whether the composite iterative learning control approach achieves better control results than pure feedback contro! was obtained for varying references. The convergence property of the closed-loop system was rigorously studied and the saturation problem was also addressed in the controller. The designed composite iterative learning control strategy is successfully employed in an atomic force microscope system, with both simulation and experimental results clearly demonstrating its superior performance.
文摘This paper presents a novel design method of force rebalance control for the sense mode of micromachined vibratory gyroscopes.Specific theoretical deductions are performed to identify a precise linear model of the open loop system of the sense mode,which is crucial for the PI controller design.The frequency responses obtained by experimental tests agree well with those calculated with the theoretical model,indicating the accuracy of the theoretical analyses.Experimental results demonstrate that the bandwidth of the closed loop is extended to 94.8 Hz from 2.3 Hz in the open loop and the quadrature signal is suppressed by about 64 dBV in the closed loop system.The overshoot and stable time in the step response of the closed loop system are measured to be about 15% and 35 ms,respectively.The mode-splitting gyroscope with the closed loop controlled sense mode achieves a scale factor of 41.0 mV/deg/s with nonlinearity of 0.09% and asymmetry of 1%,and a bias instability of 4.0 °/h with angle random walk of 0.171 deg/h1/2.
