We consider a scenario where an unmanned aerial vehicle(UAV),a typical unmanned aerial system(UAS),transmits confidential data to a moving ground target in the presence of multiple eavesdroppers.Multiple friendly reco...We consider a scenario where an unmanned aerial vehicle(UAV),a typical unmanned aerial system(UAS),transmits confidential data to a moving ground target in the presence of multiple eavesdroppers.Multiple friendly reconfigurable intelligent surfaces(RISs) help to secure the UAV-target communication and improve the energy efficiency of the UAV.We formulate an optimization problem to minimize the energy consumption of the UAV,subject to the mobility constraint of the UAV and that the achievable secrecy rate at the target is over a given threshold.We present an online planning method following the framework of model predictive control(MPC) to jointly optimize the motion of the UAV and the configurations of the RISs.The effectiveness of the proposed method is validated via computer simulations.展开更多
Fault prediction technology of running state of electromechanical systems is one of the key technologies that ensure safe and reliable operation of electromechanical equipment in health state. For multiple types of mo...Fault prediction technology of running state of electromechanical systems is one of the key technologies that ensure safe and reliable operation of electromechanical equipment in health state. For multiple types of modern, high-end and key electromechanical equipment, this paper will describe the early faults prediction method for multi-type electromechanical systems, which is favorable for predicting early faults of complex electromechanical systems in non-stationary, nonlinear, variable working conditions and long-time running state; the paper shall introduce the reconfigurable integration technology of series safety monitoring systems based on which the integrated development platform of series safety monitoring systems is built. This platform can adapt to integrated R&D of series safety monitoring systems characterized by high technology, multiple species and low volume. With the help of this platform, series safety monitoring systems were developed, and the Remote Network Security Monitoring Center for Facility Groups was built. Experimental research and engineering applications show that: this new fault prediction method has realized the development trend features extraction of typical electromechanical systems, multi-information fusion, intelligent information decision-making and so on, improving the processing accuracy, relevance and applicability of information; new reconfigurable integration technologies have improved the integration level and R&D efficiency of series safety monitoring systems as well as expanded the scope of application; the series safety monitoring systems developed based on reconfigurable integration platform has already played an important role in many aspects including ensuring safety operation of equipment, stabilizing product quality, optimizing running state, saving energy consumption, reducing environmental pollution, improving working conditions, carrying out scientific maintenance, advancing equipment utilization, saving maintenance charge and enhancing the level of information management.展开更多
An overview on nonlinear reconfigurable flight control approaches that have been demonstrated in flight-test or highfidelity simulation is presented. Various approaches for reconfigurable flight control systems are co...An overview on nonlinear reconfigurable flight control approaches that have been demonstrated in flight-test or highfidelity simulation is presented. Various approaches for reconfigurable flight control systems are considered, including nonlinear dynamic inversion, parameter identification and neural network technologies, backstepping and model predictive control approaches. The recent research work, flight tests, and potential strength and weakness of each approach are discussed objectively in order to give readers and researchers some reference. Finally, possible future directions and open problems in this area are addressed.展开更多
A decentralized adaptive neural network sliding mode position/force control scheme is proposed for constrained reconfigurable manipulators. Different from the decentralized control strategy in multi-manipulator cooper...A decentralized adaptive neural network sliding mode position/force control scheme is proposed for constrained reconfigurable manipulators. Different from the decentralized control strategy in multi-manipulator cooperation, the proposed decentralized position/force control scheme can be applied to series constrained reconfigurable manipulators. By multiplying each row of Jacobian matrix in the dynamics by contact force vector, the converted joint torque is obtained. Furthermore, using desired information of other joints instead of their actual values, the dynamics can be represented as a set of interconnected subsystems by model decomposition technique. An adaptive neural network controller is introduced to approximate the unknown dynamics of subsystem. The interconnection and the whole error term are removed by employing an adaptive sliding mode term. And then, the Lyapunov stability theory guarantees the stability of the closed-loop system. Finally, two reconfigurable manipulators with different configurations are employed to show the effectiveness of the proposed decentralized position/force control scheme.展开更多
A virtual reconfigurable architecture(VRA)-based evolvable hardware is proposed for automatic synthesis of combinational logic circuits at gate-level.The proposed VRA is implemented by a Celoxica RC1000 peripheral com...A virtual reconfigurable architecture(VRA)-based evolvable hardware is proposed for automatic synthesis of combinational logic circuits at gate-level.The proposed VRA is implemented by a Celoxica RC1000 peripheral component interconnect(PCI)board with an Xilinx Virtex xcv2000E field programmable gate array(FPGA).To improve the quality of the evolved circuits,the VRA works through a two-stage evolution: finding a functional circuit and minimizing the number of logic gates used in a feasible circuit.To optimize the algorithm performance in the two-stage evolutionary process and set free the user from the time-consuming process of mutation parameter tuning,a self-adaptive mutation rate control(SAMRC)scheme is introduced.In the evolutionary process,the mutation rate control parameters are encoded as additional genes in the chromosome and also undergo evolutionary operations.The efficiency of the proposed methodology is tested with the evolutions of a 4-bit even parity function,a 2-bit multiplier,and a 3-bit multiplier.The obtained results demonstrate that our scheme improves the evolutionary design of combinational logic circuits in terms of quality of the evolved circuit as well as the computational effort,when compared to the existing evolvable hardware approaches.展开更多
Based on the idea that modules are independent of machines, different combinations of modules and machines result in different configurations and the system performances differ under different configurations, a kind o...Based on the idea that modules are independent of machines, different combinations of modules and machines result in different configurations and the system performances differ under different configurations, a kind of cyclic reconfigurable flow shops are proposed for the new manufacturing paradigm-reconfigurable manufacturing system. The cyclic reconfigurable flow shop is modeled as a timed event graph. The optimal configuration is defined as the one under which the cyclic reconfigurable flow shop functions with the minimum cycle time and the minimum number of pallets. The optimal configuration, the minimum cycle time and the minimum number of pallets can be obtained in two steps.展开更多
This paper proposes a quantitative reconfigurability evaluation method for control systems with actuator saturation and additive faults from the perspective of system stability.Placing the saturated feedback law in th...This paper proposes a quantitative reconfigurability evaluation method for control systems with actuator saturation and additive faults from the perspective of system stability.Placing the saturated feedback law in the convex hull of a group of auxiliary linear controls,the sufficient reconfigurability conditions for the system under additive faults are derived using invariant sets.These conditions are then expressed as linear matrix inequalities(LMIs)and applied to quantify the degree of reconfigurability for the fault system.The largest fault magnitude for which the system can be stabilized,the largest initial state domain from which all the trajectories are convergent,and the minimum final state domain to which the trajectories will converge are investigated.The effectiveness of the proposed method is illustrated through an application example.展开更多
针对在GPS信号弱/拒止和环境感知欠缺的环境下可重构海洋浮体的协同控制问题,本文提出了一种基于定相对位姿(Determined relative pose,DRP)视觉伺服模型的鲁棒非线性模型预测控制(Nonlinear model predictive control,NMPC)方案。可重...针对在GPS信号弱/拒止和环境感知欠缺的环境下可重构海洋浮体的协同控制问题,本文提出了一种基于定相对位姿(Determined relative pose,DRP)视觉伺服模型的鲁棒非线性模型预测控制(Nonlinear model predictive control,NMPC)方案。可重构海洋浮体的视觉伺服问题难点主要包括环境干扰强、系统非线性程度高、视觉伺服易陷入局部极值和可见性约束强。为应对这些难题,该视觉伺服控制策略需要实现:被控船仅依靠视觉信息进行多船协同控制;视觉伺服模型收敛性好;控制器具有一定鲁棒性且处理非线性系统和约束条件的能力强。为此,本研究首先建立了单浮体的动力学模型;然后将视觉模型、被控船艏摇信息及相机云台转角信息整合到系统状态中,形成了DRP模型,从而保证了双浮体视觉伺服控制结束后相对位姿的唯一性;接着结合浮体动力学模型和DRP模型,建立了基于图像的视觉伺服(Image based visual servo,IBVS)的系统模型,并对该系统模型进行分析,进而据此设计了鲁棒的NMPC控制器,以保证视觉伺服任务可以在强外界干扰的环境下进行;最后通过大量数值仿真实验验证了该方案的有效性。这些实验结果不仅证明了控制策略的稳定性和准确性,还展示了其在复杂环境下的鲁棒性能。展开更多
基金funding from the Australian Government,via grant AUSMURIB000001 associated with ONR MURI Grant N00014-19-1-2571。
文摘We consider a scenario where an unmanned aerial vehicle(UAV),a typical unmanned aerial system(UAS),transmits confidential data to a moving ground target in the presence of multiple eavesdroppers.Multiple friendly reconfigurable intelligent surfaces(RISs) help to secure the UAV-target communication and improve the energy efficiency of the UAV.We formulate an optimization problem to minimize the energy consumption of the UAV,subject to the mobility constraint of the UAV and that the achievable secrecy rate at the target is over a given threshold.We present an online planning method following the framework of model predictive control(MPC) to jointly optimize the motion of the UAV and the configurations of the RISs.The effectiveness of the proposed method is validated via computer simulations.
基金Supported by National Natural Science Fund Project(51275052)Key project supported by Beijing Municipal Natural Science Foundation(3131002)Open topic of Key Laboratory of Key Laboratory of Modern Measurement & Control Technology,Ministry of Education(KF20141123202,KF20111123201)
文摘Fault prediction technology of running state of electromechanical systems is one of the key technologies that ensure safe and reliable operation of electromechanical equipment in health state. For multiple types of modern, high-end and key electromechanical equipment, this paper will describe the early faults prediction method for multi-type electromechanical systems, which is favorable for predicting early faults of complex electromechanical systems in non-stationary, nonlinear, variable working conditions and long-time running state; the paper shall introduce the reconfigurable integration technology of series safety monitoring systems based on which the integrated development platform of series safety monitoring systems is built. This platform can adapt to integrated R&D of series safety monitoring systems characterized by high technology, multiple species and low volume. With the help of this platform, series safety monitoring systems were developed, and the Remote Network Security Monitoring Center for Facility Groups was built. Experimental research and engineering applications show that: this new fault prediction method has realized the development trend features extraction of typical electromechanical systems, multi-information fusion, intelligent information decision-making and so on, improving the processing accuracy, relevance and applicability of information; new reconfigurable integration technologies have improved the integration level and R&D efficiency of series safety monitoring systems as well as expanded the scope of application; the series safety monitoring systems developed based on reconfigurable integration platform has already played an important role in many aspects including ensuring safety operation of equipment, stabilizing product quality, optimizing running state, saving energy consumption, reducing environmental pollution, improving working conditions, carrying out scientific maintenance, advancing equipment utilization, saving maintenance charge and enhancing the level of information management.
基金supported by the National Natural Science Foundation of China (61273171)the National Aerospace Science Foundation of China (2011ZA52009)
文摘An overview on nonlinear reconfigurable flight control approaches that have been demonstrated in flight-test or highfidelity simulation is presented. Various approaches for reconfigurable flight control systems are considered, including nonlinear dynamic inversion, parameter identification and neural network technologies, backstepping and model predictive control approaches. The recent research work, flight tests, and potential strength and weakness of each approach are discussed objectively in order to give readers and researchers some reference. Finally, possible future directions and open problems in this area are addressed.
基金Project(61374051,61603387)supported by the National Natural Science Foundation of ChinaProjects(20150520112JH,20160414033GH)supported by the Scientific and Technological Development Plan in Jilin Province of ChinaProject(20150102)supported by Opening Funding of State Key Laboratory of Management and Control for Complex Systems,China
文摘A decentralized adaptive neural network sliding mode position/force control scheme is proposed for constrained reconfigurable manipulators. Different from the decentralized control strategy in multi-manipulator cooperation, the proposed decentralized position/force control scheme can be applied to series constrained reconfigurable manipulators. By multiplying each row of Jacobian matrix in the dynamics by contact force vector, the converted joint torque is obtained. Furthermore, using desired information of other joints instead of their actual values, the dynamics can be represented as a set of interconnected subsystems by model decomposition technique. An adaptive neural network controller is introduced to approximate the unknown dynamics of subsystem. The interconnection and the whole error term are removed by employing an adaptive sliding mode term. And then, the Lyapunov stability theory guarantees the stability of the closed-loop system. Finally, two reconfigurable manipulators with different configurations are employed to show the effectiveness of the proposed decentralized position/force control scheme.
基金Projects(61203308,61309014)supported by the National Natural Science Foundation of China
文摘A virtual reconfigurable architecture(VRA)-based evolvable hardware is proposed for automatic synthesis of combinational logic circuits at gate-level.The proposed VRA is implemented by a Celoxica RC1000 peripheral component interconnect(PCI)board with an Xilinx Virtex xcv2000E field programmable gate array(FPGA).To improve the quality of the evolved circuits,the VRA works through a two-stage evolution: finding a functional circuit and minimizing the number of logic gates used in a feasible circuit.To optimize the algorithm performance in the two-stage evolutionary process and set free the user from the time-consuming process of mutation parameter tuning,a self-adaptive mutation rate control(SAMRC)scheme is introduced.In the evolutionary process,the mutation rate control parameters are encoded as additional genes in the chromosome and also undergo evolutionary operations.The efficiency of the proposed methodology is tested with the evolutions of a 4-bit even parity function,a 2-bit multiplier,and a 3-bit multiplier.The obtained results demonstrate that our scheme improves the evolutionary design of combinational logic circuits in terms of quality of the evolved circuit as well as the computational effort,when compared to the existing evolvable hardware approaches.
基金Supported by National Key Fundamental Research and Development Project of P. R. China (2002CB312200)
文摘Based on the idea that modules are independent of machines, different combinations of modules and machines result in different configurations and the system performances differ under different configurations, a kind of cyclic reconfigurable flow shops are proposed for the new manufacturing paradigm-reconfigurable manufacturing system. The cyclic reconfigurable flow shop is modeled as a timed event graph. The optimal configuration is defined as the one under which the cyclic reconfigurable flow shop functions with the minimum cycle time and the minimum number of pallets. The optimal configuration, the minimum cycle time and the minimum number of pallets can be obtained in two steps.
基金This work was supported by the National Natural Science Funds for Distinguished Young Scholars of China(61525301)the National Natural Science Fund for Excellent Young Scholars of China(62022013)the National Natural Science Foundation of China(61690215).
文摘This paper proposes a quantitative reconfigurability evaluation method for control systems with actuator saturation and additive faults from the perspective of system stability.Placing the saturated feedback law in the convex hull of a group of auxiliary linear controls,the sufficient reconfigurability conditions for the system under additive faults are derived using invariant sets.These conditions are then expressed as linear matrix inequalities(LMIs)and applied to quantify the degree of reconfigurability for the fault system.The largest fault magnitude for which the system can be stabilized,the largest initial state domain from which all the trajectories are convergent,and the minimum final state domain to which the trajectories will converge are investigated.The effectiveness of the proposed method is illustrated through an application example.
文摘受到战争等特殊环境下部分节点导航拒止、节点移动性与环境干扰所带来的影响,快速进行测控网络拓扑重构是保证连续测控关键。为了解决上述问题,针对多体制无人集群测控网络的场景,提出一种基于多智能体深度确定性策略梯度(multi-agent deep deterministic policy gradient,MADDPG)的分布式多智能体测控网络群切换算法。该算法运用局部可观测马尔可夫决策模型,并考虑最小连通度、能耗与测控精度设计奖励函数,构建可靠的测控定位系统。仿真结果表明,该算法在不同的干扰环境下能有效抵抗外界干扰,保证测控定位的正常运行,与传统切换算法相比切换成功率提升12%以上。
文摘针对在GPS信号弱/拒止和环境感知欠缺的环境下可重构海洋浮体的协同控制问题,本文提出了一种基于定相对位姿(Determined relative pose,DRP)视觉伺服模型的鲁棒非线性模型预测控制(Nonlinear model predictive control,NMPC)方案。可重构海洋浮体的视觉伺服问题难点主要包括环境干扰强、系统非线性程度高、视觉伺服易陷入局部极值和可见性约束强。为应对这些难题,该视觉伺服控制策略需要实现:被控船仅依靠视觉信息进行多船协同控制;视觉伺服模型收敛性好;控制器具有一定鲁棒性且处理非线性系统和约束条件的能力强。为此,本研究首先建立了单浮体的动力学模型;然后将视觉模型、被控船艏摇信息及相机云台转角信息整合到系统状态中,形成了DRP模型,从而保证了双浮体视觉伺服控制结束后相对位姿的唯一性;接着结合浮体动力学模型和DRP模型,建立了基于图像的视觉伺服(Image based visual servo,IBVS)的系统模型,并对该系统模型进行分析,进而据此设计了鲁棒的NMPC控制器,以保证视觉伺服任务可以在强外界干扰的环境下进行;最后通过大量数值仿真实验验证了该方案的有效性。这些实验结果不仅证明了控制策略的稳定性和准确性,还展示了其在复杂环境下的鲁棒性能。
