An optimal burst height is required for the fly-over and shoot-down smart ammunition with an EFP warhead at the instant of explosion which brings a special requirement to the miss distance of the terminal guidance law...An optimal burst height is required for the fly-over and shoot-down smart ammunition with an EFP warhead at the instant of explosion which brings a special requirement to the miss distance of the terminal guidance law. In this paper, a guidance law based on the virtual target scheme is proposed. First, the practical pursuit-evasion issue between the ammunition and the target with specific miss distance is transformed into a virtuai pursuit-evasion problem with zero miss distance. Secondly, a complete three-dimensional pursuit-evasion kinematics model is established without any simplifications. And then, a suboptimal guidance law is designed based on the θ-D method which has constraints of the elevation and azimuth angular velocity of the virtual line of sight （LOS）. Finally, in order to verify the performance of the proposed guidance law, three test cases are conducted. Numericai results show that under the proposed terminal guidance law, the smart ammunition not only can fly above the target with an optimal burst height but also have a smaller normal acceleration on the terminal trajectory.展开更多
The paper proposes a Virtual Target Guidance(VTG)-based distributed Model Predictive Control(MPC) scheme for formation control of multiple Unmanned Aerial Vehicles(UAVs).First, a framework of distributed MPC scheme is...The paper proposes a Virtual Target Guidance(VTG)-based distributed Model Predictive Control(MPC) scheme for formation control of multiple Unmanned Aerial Vehicles(UAVs).First, a framework of distributed MPC scheme is designed in which each UAV only shares the information with its neighbors, and the obtained local Finite-Horizon Optimal Control Problem(FHOCP) can be solved by swarm intelligent optimization algorithm.Then, a VTG approach is developed and integrated into the distributed MPC scheme to achieve trajectory tracking and obstacle avoidance.Further, an event-triggered mechanism is proposed to reduce the computational burden for UAV formation control, which takes into consideration the predictive state errors as well as the convergence of cost function.Numerical simulations show that the proposed VTG-based distributed MPC scheme is more computationally efficient to achieve formation control of multiple UAVs in comparison with the traditional distributed MPC method.展开更多
A novel robot navigation algorithm with global path generation capability is presented. Local minimum is a most intractable but is an encountered frequently problem in potential field based robot navigation.Through ap...A novel robot navigation algorithm with global path generation capability is presented. Local minimum is a most intractable but is an encountered frequently problem in potential field based robot navigation.Through appointing appropriately some virtual local targets on the journey, it can be solved effectively. The key concept employed in this algorithm are the rules that govern when and how to appoint these virtual local targets. When the robot finds itself in danger of local minimum, a virtual local target is appointed to replace the global goal temporarily according to the rules. After the virtual target is reached, the robot continues on its journey by heading towards the global goal. The algorithm prevents the robot from running into local minima anymore. Simulation results showed that it is very effective in complex obstacle environments.展开更多
促使风电、光伏等分布式能源和电动汽车保有量快速增长。考虑电动汽车到电网(vehicle to grid,V2G)能量互动对多元化能源发电出力随机性及波动性的平抑作用,以及提升风/光电的消纳水平,采用虚拟电厂(virtual power plant,VPP)技术实现...促使风电、光伏等分布式能源和电动汽车保有量快速增长。考虑电动汽车到电网(vehicle to grid,V2G)能量互动对多元化能源发电出力随机性及波动性的平抑作用,以及提升风/光电的消纳水平,采用虚拟电厂(virtual power plant,VPP)技术实现对二者的统一协调管理,进而结合电动汽车全生命周期碳排放数量和分布式能源运行时碳排放数量,构建电动汽车参与的虚拟电厂整体多目标优化模型,采用粒子群优化算法对该模型进行求解,从而优化系统运行成本及碳排放成本。在结合真实数据配置的算例模型上进行实验分析,实验结果表明,提出的优化模型可以有效调度虚拟电厂各要素,充分发挥电动汽车V2G入网充放电带来的运行和碳排放收益,可以为低碳目标背景下电网系统的安全稳定运行提供技术参考。展开更多
基于多靶点虚拟筛选、网络药理学分析和体外实验,探讨强肝胶囊(QGC)治疗非酒精性脂肪性肝病(NAFLD)的潜在作用机制。利用基于PPARα/γ、FXR及sEH的多靶点虚拟筛选选出QGC中具有治疗NAFLD的活性成分,运用网络药理学预测活性成分靶点、...基于多靶点虚拟筛选、网络药理学分析和体外实验,探讨强肝胶囊(QGC)治疗非酒精性脂肪性肝病(NAFLD)的潜在作用机制。利用基于PPARα/γ、FXR及sEH的多靶点虚拟筛选选出QGC中具有治疗NAFLD的活性成分,运用网络药理学预测活性成分靶点、疾病相关靶点,筛选调控疾病的关键靶点,通过Discovery Studio 2020软件和Gromacs软件对关键活性成分和关键靶点进行分子对接和分子动力学模拟分析。最后,通过实验验证QGC中的关键活性成分对肝细胞脂肪变性的改善作用。多靶点虚拟筛选得到235个QGC活性成分,网络药理学分析得到320个成分-疾病共同靶点。分子对接结果表明,芹菜素、异鼠李素、迷迭香酸、大黄素甲醚、木犀草素与关键靶点PTPN1、PPARα、PPARγ、AR具有良好的结合能力。分子动力学模拟进一步验证了迷迭香酸、大黄素甲醚等化合物与关键靶点具有良好的结合稳定性。体外实验结果显示,5个关键活性成分均能改善HepG2细胞的脂肪变性,其中异鼠李素、迷迭香酸、大黄素甲醚改善细胞脂肪变性模型的效果最佳。本研究通过多层面探讨,为QGC在NAFLD治疗中的开发和应用提供理论依据。展开更多
目的:研究抗肿瘤靶点人MutT同源体1蛋白(Human MutT Homolog-1,MTH1)抑制剂的构效关系,构建药效团筛选模型筛选潜在的MTH1抑制剂。方法:采用计算机辅助药物设计方法,通过Discovery Studio 3.0软件包中分子共同特征药效团HipHop算法,使...目的:研究抗肿瘤靶点人MutT同源体1蛋白(Human MutT Homolog-1,MTH1)抑制剂的构效关系,构建药效团筛选模型筛选潜在的MTH1抑制剂。方法:采用计算机辅助药物设计方法,通过Discovery Studio 3.0软件包中分子共同特征药效团HipHop算法,使用14个已知MTH1抑制剂分子作为训练集构建药效团模型,并通过Decoy Set验证准确性。结果:获得富集率为13.1的HipHop药效团模型,通过分子对接验证虚拟筛选出的75个候选化合物,得到先导化合物GK01945和HTS07767,能与受体形成良好的相互作用。结论:构建的药效团模型可以作为筛选模型,筛选出的MTH1潜在抑制剂,为抗肿瘤药物MTH1抑制剂开发提供了新思路。展开更多
基金Supported by the Fundamental Scientific Research Program of China Ministries and Commissions(B2220132013)
文摘An optimal burst height is required for the fly-over and shoot-down smart ammunition with an EFP warhead at the instant of explosion which brings a special requirement to the miss distance of the terminal guidance law. In this paper, a guidance law based on the virtual target scheme is proposed. First, the practical pursuit-evasion issue between the ammunition and the target with specific miss distance is transformed into a virtuai pursuit-evasion problem with zero miss distance. Secondly, a complete three-dimensional pursuit-evasion kinematics model is established without any simplifications. And then, a suboptimal guidance law is designed based on the θ-D method which has constraints of the elevation and azimuth angular velocity of the virtual line of sight （LOS）. Finally, in order to verify the performance of the proposed guidance law, three test cases are conducted. Numericai results show that under the proposed terminal guidance law, the smart ammunition not only can fly above the target with an optimal burst height but also have a smaller normal acceleration on the terminal trajectory.
基金supported in part by the National Natural Science Foundation of China(No.61803009)Fundamental Research Funds for the Central Universities,China(No.YWF-19-BJ-J-205)Aeronautical Science Foundation of China(No.20175851032)。
文摘The paper proposes a Virtual Target Guidance(VTG)-based distributed Model Predictive Control(MPC) scheme for formation control of multiple Unmanned Aerial Vehicles(UAVs).First, a framework of distributed MPC scheme is designed in which each UAV only shares the information with its neighbors, and the obtained local Finite-Horizon Optimal Control Problem(FHOCP) can be solved by swarm intelligent optimization algorithm.Then, a VTG approach is developed and integrated into the distributed MPC scheme to achieve trajectory tracking and obstacle avoidance.Further, an event-triggered mechanism is proposed to reduce the computational burden for UAV formation control, which takes into consideration the predictive state errors as well as the convergence of cost function.Numerical simulations show that the proposed VTG-based distributed MPC scheme is more computationally efficient to achieve formation control of multiple UAVs in comparison with the traditional distributed MPC method.
文摘A novel robot navigation algorithm with global path generation capability is presented. Local minimum is a most intractable but is an encountered frequently problem in potential field based robot navigation.Through appointing appropriately some virtual local targets on the journey, it can be solved effectively. The key concept employed in this algorithm are the rules that govern when and how to appoint these virtual local targets. When the robot finds itself in danger of local minimum, a virtual local target is appointed to replace the global goal temporarily according to the rules. After the virtual target is reached, the robot continues on its journey by heading towards the global goal. The algorithm prevents the robot from running into local minima anymore. Simulation results showed that it is very effective in complex obstacle environments.
文摘促使风电、光伏等分布式能源和电动汽车保有量快速增长。考虑电动汽车到电网(vehicle to grid,V2G)能量互动对多元化能源发电出力随机性及波动性的平抑作用,以及提升风/光电的消纳水平,采用虚拟电厂(virtual power plant,VPP)技术实现对二者的统一协调管理,进而结合电动汽车全生命周期碳排放数量和分布式能源运行时碳排放数量,构建电动汽车参与的虚拟电厂整体多目标优化模型,采用粒子群优化算法对该模型进行求解,从而优化系统运行成本及碳排放成本。在结合真实数据配置的算例模型上进行实验分析,实验结果表明,提出的优化模型可以有效调度虚拟电厂各要素,充分发挥电动汽车V2G入网充放电带来的运行和碳排放收益,可以为低碳目标背景下电网系统的安全稳定运行提供技术参考。
文摘基于多靶点虚拟筛选、网络药理学分析和体外实验,探讨强肝胶囊(QGC)治疗非酒精性脂肪性肝病(NAFLD)的潜在作用机制。利用基于PPARα/γ、FXR及sEH的多靶点虚拟筛选选出QGC中具有治疗NAFLD的活性成分,运用网络药理学预测活性成分靶点、疾病相关靶点,筛选调控疾病的关键靶点,通过Discovery Studio 2020软件和Gromacs软件对关键活性成分和关键靶点进行分子对接和分子动力学模拟分析。最后,通过实验验证QGC中的关键活性成分对肝细胞脂肪变性的改善作用。多靶点虚拟筛选得到235个QGC活性成分,网络药理学分析得到320个成分-疾病共同靶点。分子对接结果表明,芹菜素、异鼠李素、迷迭香酸、大黄素甲醚、木犀草素与关键靶点PTPN1、PPARα、PPARγ、AR具有良好的结合能力。分子动力学模拟进一步验证了迷迭香酸、大黄素甲醚等化合物与关键靶点具有良好的结合稳定性。体外实验结果显示,5个关键活性成分均能改善HepG2细胞的脂肪变性,其中异鼠李素、迷迭香酸、大黄素甲醚改善细胞脂肪变性模型的效果最佳。本研究通过多层面探讨,为QGC在NAFLD治疗中的开发和应用提供理论依据。
