This paper proposes a multiple-constraints-guaranteed midcourse guidance law for the interception of the hypersonic targets. In traditional midcourse law design, the constraints of the aero-thermal heating are rarely ...This paper proposes a multiple-constraints-guaranteed midcourse guidance law for the interception of the hypersonic targets. In traditional midcourse law design, the constraints of the aero-thermal heating are rarely taken into consideration. The performance of the infrared detection system may be degraded and the instability of the flight control system may be induced.To address this problem, a state-constrained model predictive static programming method is introduced such that both terminal constraints(position and angle) and optimal energy consumption can be ensured. As a result, a sub-optimal midcourse guidance,guaranteeing the aforementioned multiple-constraints to be never violated, is synthesized. Simulation results demonstrate the effectiveness of the proposed method.展开更多
In the forward channel of a networked control system （NCS）, by defining the network states as a hidden Markov chain and quantizing the network-induced delays to a discrete sequence distributing over a finite time in...In the forward channel of a networked control system （NCS）, by defining the network states as a hidden Markov chain and quantizing the network-induced delays to a discrete sequence distributing over a finite time interval, the relation between the network states and the network-induced delays is modelled as a discrete-time hidden Markov model （DTHMM）. The expectation maximization （EM） algorithm is introduced to derive the maximumlikelihood estimation （MLE） of the parameters of the DTHMM. Based on the derived DTHMM, the Viterbi algorithm is introduced to predict the controller-to-actuator （C-A） delay during the current sampling period. The simulation experiments demonstrate the effectiveness of the modelling and predicting methods proposed.展开更多
基于模块化多电平变换器的有源电力滤波器MMC-APF(modular multilevel converter-based active power filter)是用来处理非线性负载对电网带来的污染问题最有效的拓扑之一。提出了一种基于改进有限状态多步模型预测控制的MMC-APF,仅通...基于模块化多电平变换器的有源电力滤波器MMC-APF(modular multilevel converter-based active power filter)是用来处理非线性负载对电网带来的污染问题最有效的拓扑之一。提出了一种基于改进有限状态多步模型预测控制的MMC-APF,仅通过基波同步旋转坐标系实现对所有谐波的控制。首先,使用PI加重复控制的电流环复合控制得到上、下桥臂预导通子模块数,在此基础上进行多步交流侧电流模型预测,最终得到桥臂投入子模块数的最优解,缩小了寻找目标函数最优电平的搜索范围,无需设计权重因子,每相桥臂子模块的总投入数为[N-1,N+1],交流侧输出电平数最大可达2N+1,提高了MMC-APF交流侧电流补偿精度,并改善了系统动态性能。最后,搭建了MMC-APF平台,仿真和实验结果与理论分析一致,进一步验证了所提研究方案的可行性和有效性。展开更多
基金supported by the National Natural Science Foundation of China(61503302)the joint fund of the National Natural Science Foundation Committee and China Academy of Engineering Physics(U1630127)
文摘This paper proposes a multiple-constraints-guaranteed midcourse guidance law for the interception of the hypersonic targets. In traditional midcourse law design, the constraints of the aero-thermal heating are rarely taken into consideration. The performance of the infrared detection system may be degraded and the instability of the flight control system may be induced.To address this problem, a state-constrained model predictive static programming method is introduced such that both terminal constraints(position and angle) and optimal energy consumption can be ensured. As a result, a sub-optimal midcourse guidance,guaranteeing the aforementioned multiple-constraints to be never violated, is synthesized. Simulation results demonstrate the effectiveness of the proposed method.
基金supported in part by the National Natural Science Foundation of China (60774098 60843003+3 种基金 50905172)the Science Foundation of Anhui Province (090412071 090412040)the University of Science and Technology of China Initiative Foundation
文摘In the forward channel of a networked control system （NCS）, by defining the network states as a hidden Markov chain and quantizing the network-induced delays to a discrete sequence distributing over a finite time interval, the relation between the network states and the network-induced delays is modelled as a discrete-time hidden Markov model （DTHMM）. The expectation maximization （EM） algorithm is introduced to derive the maximumlikelihood estimation （MLE） of the parameters of the DTHMM. Based on the derived DTHMM, the Viterbi algorithm is introduced to predict the controller-to-actuator （C-A） delay during the current sampling period. The simulation experiments demonstrate the effectiveness of the modelling and predicting methods proposed.
文摘基于模块化多电平变换器的有源电力滤波器MMC-APF(modular multilevel converter-based active power filter)是用来处理非线性负载对电网带来的污染问题最有效的拓扑之一。提出了一种基于改进有限状态多步模型预测控制的MMC-APF,仅通过基波同步旋转坐标系实现对所有谐波的控制。首先,使用PI加重复控制的电流环复合控制得到上、下桥臂预导通子模块数,在此基础上进行多步交流侧电流模型预测,最终得到桥臂投入子模块数的最优解,缩小了寻找目标函数最优电平的搜索范围,无需设计权重因子,每相桥臂子模块的总投入数为[N-1,N+1],交流侧输出电平数最大可达2N+1,提高了MMC-APF交流侧电流补偿精度,并改善了系统动态性能。最后,搭建了MMC-APF平台,仿真和实验结果与理论分析一致,进一步验证了所提研究方案的可行性和有效性。
