To better complete various missions, it is necessary to plan an optimal trajectory or provide the optimal control law for the multirole missile according to the actual situation, including launch conditions and target...To better complete various missions, it is necessary to plan an optimal trajectory or provide the optimal control law for the multirole missile according to the actual situation, including launch conditions and target location. Since trajectory optimization struggles to meet real-time requirements, the emergence of data-based generation methods has become a significant focus in contemporary research. However, due to the large differences in the characteristics of the optimal control laws caused by the diversity of tasks, it is difficult to achieve good prediction results by modeling all data with one single model.Therefore, the modeling idea of the mixture of experts(MoE) is adopted. Firstly, the K-means clustering algorithm is used to partition the sample data set, and the corresponding neural network classification model is established as the gate switch of MoE. Then, the expert models, i.e., the mappings from the generation conditions to the optimal control law represented by the results of principal component analysis(PCA), are represented by Kriging models. Finally, multiple rounds of accuracy evaluation, sample supplementation, and model updating are conducted to improve the generation accuracy. The Monte Carlo simulation shows that the accuracy of the proposed model reaches 96% and the generation efficiency meets the real-time requirement.展开更多
This paper bursts the bondage of conventional no-burn thought, presents an optimum strategy permitting burn appear in grinding roughing stage, but the burning layer can be summed on the following finishing stage. On t...This paper bursts the bondage of conventional no-burn thought, presents an optimum strategy permitting burn appear in grinding roughing stage, but the burning layer can be summed on the following finishing stage. On the base of the basic grinding models, the objective function and constrained functions for the multiparameter optimum grinding models had been built in this paper. By the computer simulation, the nonlinear optimum grinding control parameters had been obtained, and the truth grinding process had been controlled by these parameters. The results of simulation and the experiments proved the exactitude of the optimum models and the feasibility of the optimum strategy. This paper had also created the precondition for the grinding automation, virtual grinding and intelligent grinding system for cylindrical grinding process.展开更多
在电气化铁路牵引供电系统中,铁路能量路由器(railway energy router,RER)用于回收列车制动能量、接入光伏等新能源,同时改善负序、无功等电能质量,但是既有结构包含两套逆变器和变压器,存在成本高、工程应用难的问题。为此,提出一种基...在电气化铁路牵引供电系统中,铁路能量路由器(railway energy router,RER)用于回收列车制动能量、接入光伏等新能源,同时改善负序、无功等电能质量,但是既有结构包含两套逆变器和变压器,存在成本高、工程应用难的问题。为此,提出一种基于跨相式单相逆变器的新型铁路能量路由器结构,其交流侧跨接α/β相牵引母线、直流侧接入光伏储能。首先,推导新型结构的数学模型和工作原理;然后,针对逆变器传统两端口模式转变为RER的三端口模式存在的有功/无功耦合问题,提出增加无功补偿装置的硬件解耦方法;其次,针对新型RER三端口间多向能流问题,提出一种多层协调优化控制策略。最后,基于典型工况及实测数据,进行了仿真验证,结果表明:三相电压不平衡度从2.52%降低至1.58%,平均功率因数从0.688上升至0.966,再生制动回收率61.65%,光伏消纳率94.16%;主设备容量降低42.31%,成本降低37.23%,说明所提新型RER在实现现有RER相同功能的前提下大幅降低了成本,具有重要的理论和工程价值。展开更多
基金Defense Industrial Technology Development Program (JCKY2020204B016)National Natural Science Foundation of China (92471206)。
文摘To better complete various missions, it is necessary to plan an optimal trajectory or provide the optimal control law for the multirole missile according to the actual situation, including launch conditions and target location. Since trajectory optimization struggles to meet real-time requirements, the emergence of data-based generation methods has become a significant focus in contemporary research. However, due to the large differences in the characteristics of the optimal control laws caused by the diversity of tasks, it is difficult to achieve good prediction results by modeling all data with one single model.Therefore, the modeling idea of the mixture of experts(MoE) is adopted. Firstly, the K-means clustering algorithm is used to partition the sample data set, and the corresponding neural network classification model is established as the gate switch of MoE. Then, the expert models, i.e., the mappings from the generation conditions to the optimal control law represented by the results of principal component analysis(PCA), are represented by Kriging models. Finally, multiple rounds of accuracy evaluation, sample supplementation, and model updating are conducted to improve the generation accuracy. The Monte Carlo simulation shows that the accuracy of the proposed model reaches 96% and the generation efficiency meets the real-time requirement.
文摘This paper bursts the bondage of conventional no-burn thought, presents an optimum strategy permitting burn appear in grinding roughing stage, but the burning layer can be summed on the following finishing stage. On the base of the basic grinding models, the objective function and constrained functions for the multiparameter optimum grinding models had been built in this paper. By the computer simulation, the nonlinear optimum grinding control parameters had been obtained, and the truth grinding process had been controlled by these parameters. The results of simulation and the experiments proved the exactitude of the optimum models and the feasibility of the optimum strategy. This paper had also created the precondition for the grinding automation, virtual grinding and intelligent grinding system for cylindrical grinding process.
文摘在电气化铁路牵引供电系统中,铁路能量路由器(railway energy router,RER)用于回收列车制动能量、接入光伏等新能源,同时改善负序、无功等电能质量,但是既有结构包含两套逆变器和变压器,存在成本高、工程应用难的问题。为此,提出一种基于跨相式单相逆变器的新型铁路能量路由器结构,其交流侧跨接α/β相牵引母线、直流侧接入光伏储能。首先,推导新型结构的数学模型和工作原理;然后,针对逆变器传统两端口模式转变为RER的三端口模式存在的有功/无功耦合问题,提出增加无功补偿装置的硬件解耦方法;其次,针对新型RER三端口间多向能流问题,提出一种多层协调优化控制策略。最后,基于典型工况及实测数据,进行了仿真验证,结果表明:三相电压不平衡度从2.52%降低至1.58%,平均功率因数从0.688上升至0.966,再生制动回收率61.65%,光伏消纳率94.16%;主设备容量降低42.31%,成本降低37.23%,说明所提新型RER在实现现有RER相同功能的前提下大幅降低了成本,具有重要的理论和工程价值。
