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 proposes a loop-tube type thermoacoustic heating system without any moving parts based on the thermoacoustic effect. In a thermoacoustic heating system, the supplied sound is converted to heat and the heati...This paper proposes a loop-tube type thermoacoustic heating system without any moving parts based on the thermoacoustic effect. In a thermoacoustic heating system, the supplied sound is converted to heat and the heating point is heated. A thermoacoustic heating system differs from a thermoacoustic cooling system： The location of the reference temperature section at the heat pump is upside down. The authors construct a prototype ofthermoacoustic heating system. The experimental results show that the heating point reaches 100 ~C. It must be emphasized that, using this simple and inexpensive thermoacoustic heating system, noise, waste heat and unused heat are useful as a renewable energy source.展开更多
At present, the marine environment is faced with extremely serious eutrophication. The kelp＇s ability of taking in nitrogen and phosphorus can be fully performed so that the eutrophication problem can be effectively ...At present, the marine environment is faced with extremely serious eutrophication. The kelp＇s ability of taking in nitrogen and phosphorus can be fully performed so that the eutrophication problem can be effectively treated and solved. Based on the analysis of kelp＇s absorption of nutritive salt from aquaculture sewage, this paper further explores the bioremediation of kelp in aquaculture sea area with eutrophication in the hope of providing valuable reference for the aquaculture industry of BohaiSea.展开更多
A high resolution speed and position identification algorithm, suitable for brushless DC drives, is presented in this paper. In particular, the algorithm is proposed for BLDC （brushless DC） machines that are charact...A high resolution speed and position identification algorithm, suitable for brushless DC drives, is presented in this paper. In particular, the algorithm is proposed for BLDC （brushless DC） machines that are characterized by an un-ideal trapezoidal emfs shape. The algorithm, which is developed basing upon the MRAS technique （model reference adaptive system） and the Popov＇s hyperstability criterion, guarantees the convergence of the estimated rotor speed and position signals to their corresponding actual values. The identification procedure can be performed starting from the knowledge of low resolution rotor position signals, phase currents and the BLDC emfs shape. The identification algorithm is properly tested on a BLDC drive controlled by a predictive algorithm, by performing a simulation study in the Matlab-Simulink environment. The corresponding results have highlighted the effectiveness of the proposed sensorless predictive control system, at both low and high speed operation.展开更多
In this paper, finite sample properties of virtual reference feedback tuning control are considered, by using the theory of finite sample properties from system identification. To design a controller in closed loop sy...In this paper, finite sample properties of virtual reference feedback tuning control are considered, by using the theory of finite sample properties from system identification. To design a controller in closed loop system structure, the idea of virtual reference feedback tuning is proposed to avoid the identification process corresponding to the plant model. After constructing one identification cost without any knowledge of plant model, the author derives one bound on the difference between the expected identification cost and its sample identification cost under the condition that the number of data points is finite. Also the correlation between the plant input and external noise is considered in the derivation of this bound. Furthermore, the author continues to derive one probability bound to quantify this difference by using some probability inequalities and control theory.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 proposes a loop-tube type thermoacoustic heating system without any moving parts based on the thermoacoustic effect. In a thermoacoustic heating system, the supplied sound is converted to heat and the heating point is heated. A thermoacoustic heating system differs from a thermoacoustic cooling system： The location of the reference temperature section at the heat pump is upside down. The authors construct a prototype ofthermoacoustic heating system. The experimental results show that the heating point reaches 100 ~C. It must be emphasized that, using this simple and inexpensive thermoacoustic heating system, noise, waste heat and unused heat are useful as a renewable energy source.
文摘At present, the marine environment is faced with extremely serious eutrophication. The kelp＇s ability of taking in nitrogen and phosphorus can be fully performed so that the eutrophication problem can be effectively treated and solved. Based on the analysis of kelp＇s absorption of nutritive salt from aquaculture sewage, this paper further explores the bioremediation of kelp in aquaculture sea area with eutrophication in the hope of providing valuable reference for the aquaculture industry of BohaiSea.
文摘A high resolution speed and position identification algorithm, suitable for brushless DC drives, is presented in this paper. In particular, the algorithm is proposed for BLDC （brushless DC） machines that are characterized by an un-ideal trapezoidal emfs shape. The algorithm, which is developed basing upon the MRAS technique （model reference adaptive system） and the Popov＇s hyperstability criterion, guarantees the convergence of the estimated rotor speed and position signals to their corresponding actual values. The identification procedure can be performed starting from the knowledge of low resolution rotor position signals, phase currents and the BLDC emfs shape. The identification algorithm is properly tested on a BLDC drive controlled by a predictive algorithm, by performing a simulation study in the Matlab-Simulink environment. The corresponding results have highlighted the effectiveness of the proposed sensorless predictive control system, at both low and high speed operation.
基金supported by Jiangxi Provincial National Science Foundation under Grant No.20142BAB206020
文摘In this paper, finite sample properties of virtual reference feedback tuning control are considered, by using the theory of finite sample properties from system identification. To design a controller in closed loop system structure, the idea of virtual reference feedback tuning is proposed to avoid the identification process corresponding to the plant model. After constructing one identification cost without any knowledge of plant model, the author derives one bound on the difference between the expected identification cost and its sample identification cost under the condition that the number of data points is finite. Also the correlation between the plant input and external noise is considered in the derivation of this bound. Furthermore, the author continues to derive one probability bound to quantify this difference by using some probability inequalities and control theory.
