We propose a new approach to discuss the consensus problem of multi-agent systems with time-varying delayed control inputs, switching topologies, and stochastic cyber-attacks under hybrid-triggered mechanism.A Bernoul...We propose a new approach to discuss the consensus problem of multi-agent systems with time-varying delayed control inputs, switching topologies, and stochastic cyber-attacks under hybrid-triggered mechanism.A Bernoulli variable is used to describe the hybrid-triggered scheme, which is introduced to alleviate the burden of the network.The mathematical model of the closed-loop control system is established by taking the influences of time-varying delayed control inputs,switching topologies, and stochastic cyber-attacks into account under the hybrid-triggered scheme.A theorem as the main result is given to make the system consistent based on the theory of Lyapunov stability and linear matrix inequality.Markov jumps with uncertain rates of transitions are applied to describe the switch of topologies.Finally, a simulation example demonstrates the feasibility of the theory in this paper.展开更多
Any unknown unitary operations conditioned on a control system can be deterministically performed if ancillary subspaces are available for the target systems [Zhou X Q, et al. 2011 Nat. Commun. 2 413]. In this paper, ...Any unknown unitary operations conditioned on a control system can be deterministically performed if ancillary subspaces are available for the target systems [Zhou X Q, et al. 2011 Nat. Commun. 2 413]. In this paper, we show that previous optical schemes may be extended to general hybrid systems if unknown operations are provided by optical instruments. Moreover, a probabilistic scheme is proposed when the unknown operation may be performed on the subspaces of ancillary high-dimensional systems. Furthermore, the unknown operations conditioned on the multi-control system may be reduced to the case with a control system using additional linear circuit complexity. The new schemes may be more flexible for different systems or hybrid systems.展开更多
城市空中交通(urban air mobility, UAM),是近期解决当前地面交通拥堵困境的有效方法。因此,研究飞行汽车典型飞行任务剖面下的动力系统工作特性至关重要。由于电池能量密度的限制以及纯电动飞行汽车的里程限制,因此使用油电混合作为飞...城市空中交通(urban air mobility, UAM),是近期解决当前地面交通拥堵困境的有效方法。因此,研究飞行汽车典型飞行任务剖面下的动力系统工作特性至关重要。由于电池能量密度的限制以及纯电动飞行汽车的里程限制,因此使用油电混合作为飞行汽车的动力系统更为合理。总结垂直起降飞行汽车(vertical takeoff and landing, VTOL)任务剖面下混动系统运行性能的相关研究。基于MATLAB Simulink,提出一种混合动力的协调方法,其中同时考虑两种操作模式。根据实际操作条件,预设垂直起降和平飞两种工况下不同的操作模式。在此基础上,研究作为主要电源的增程器调节功率流和提高增程器工作效率的电池协调。直流母线电压由DC/DC转换器调节,有利于电池组的整体寿命,实现了充电和放电状态期间的功率共享。仿真结果表明:可以很好地控制直流母线电压,并且增程器和电池之间的功率共享遵循设计。展开更多
为优化燃料电池混合动力系统(fuel cell hybrid power system,FCHPS)并延长其使用寿命,该文提出一种考虑电堆性能一致性的多目标优化能量管理方法。该方法的目的是降低系统等效氢耗、提高燃料电池系统内电堆组运行效率的同时限制锂电池...为优化燃料电池混合动力系统(fuel cell hybrid power system,FCHPS)并延长其使用寿命,该文提出一种考虑电堆性能一致性的多目标优化能量管理方法。该方法的目的是降低系统等效氢耗、提高燃料电池系统内电堆组运行效率的同时限制锂电池荷电状态(state of charge,SOC)波动。由于电堆组的性能会在实际运行过程中发生退化,因此该方法还考虑了电堆组的性能状态差异,通过限制性能较差电堆的运行压力,以延长系统寿命。为实现这一目的采用樽海鞘群算法(salpswarmalgorithm,SSA)对目标函数进行优化求解,得到系统最优功率分配。最后,基于RT-LAB半实物仿真平台,将所提方法与有限状态机控制方法进行对比,实验结果表明所提出的方法能够有效降低系统氢耗,提高电堆组效率的同时减缓性能较差电堆的功率波动,维持系统一致性,有利于系统长期稳定运行。展开更多
针对由周期任务和零星任务形成的实时混合任务集进行合理调度问题,文中提出了一种基于零松弛度边界公平(Boundary Fair until Zero Laxity,BFZL)的实时混合任务算法。该算法在改进边界公平(Improved Boundary Fair,I-BF)实时混合任务算...针对由周期任务和零星任务形成的实时混合任务集进行合理调度问题,文中提出了一种基于零松弛度边界公平(Boundary Fair until Zero Laxity,BFZL)的实时混合任务算法。该算法在改进边界公平(Improved Boundary Fair,I-BF)实时混合任务算法基础上,通过引入最小松弛度优先(Least Laxity First,LLF)算法中的松弛度参数来改进判定任务的优先级,并提出基于松弛度与启发式策略相结合的启发式算法改进任务的分配策略。实验结果表明,BFZL算法能够满足系统实时性,并达到了算法优化目的。通过数据对比分析可知,该算法相比于原始算法,零星任务的平均响应时间降低了约26%,上下文切换减少了约28%,迁移减少了约50%。该算法在调度开销方面也具有一定优势。展开更多
The primary focus of this study is to investigate the control strategies of a hybrid system used in hydraulic excavators. First, the structure and evaluation target of hybrid hydraulic excavators are analyzed. Then th...The primary focus of this study is to investigate the control strategies of a hybrid system used in hydraulic excavators. First, the structure and evaluation target of hybrid hydraulic excavators are analyzed. Then the dynamic system model including batteries, motor and engine is built as the simulation environment to obtain control results. A so-called multi-work-point dynamic control strategy, which has both closed-loop speed PI (proportion integral) control and direct torque control, is proposed and studied in the simulation model. Simulation results indicate that the hybrid system with this strategy can meet the power demand and achieve better system stability and higher fuel efficiency.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61074159 and 61703286)
文摘We propose a new approach to discuss the consensus problem of multi-agent systems with time-varying delayed control inputs, switching topologies, and stochastic cyber-attacks under hybrid-triggered mechanism.A Bernoulli variable is used to describe the hybrid-triggered scheme, which is introduced to alleviate the burden of the network.The mathematical model of the closed-loop control system is established by taking the influences of time-varying delayed control inputs,switching topologies, and stochastic cyber-attacks into account under the hybrid-triggered scheme.A theorem as the main result is given to make the system consistent based on the theory of Lyapunov stability and linear matrix inequality.Markov jumps with uncertain rates of transitions are applied to describe the switch of topologies.Finally, a simulation example demonstrates the feasibility of the theory in this paper.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61303039 and 61201253)Chunying Fellowship,and Fundamental Research Funds for the Central Universities,China(Grant No.2682014CX095)
文摘Any unknown unitary operations conditioned on a control system can be deterministically performed if ancillary subspaces are available for the target systems [Zhou X Q, et al. 2011 Nat. Commun. 2 413]. In this paper, we show that previous optical schemes may be extended to general hybrid systems if unknown operations are provided by optical instruments. Moreover, a probabilistic scheme is proposed when the unknown operation may be performed on the subspaces of ancillary high-dimensional systems. Furthermore, the unknown operations conditioned on the multi-control system may be reduced to the case with a control system using additional linear circuit complexity. The new schemes may be more flexible for different systems or hybrid systems.
文摘城市空中交通(urban air mobility, UAM),是近期解决当前地面交通拥堵困境的有效方法。因此,研究飞行汽车典型飞行任务剖面下的动力系统工作特性至关重要。由于电池能量密度的限制以及纯电动飞行汽车的里程限制,因此使用油电混合作为飞行汽车的动力系统更为合理。总结垂直起降飞行汽车(vertical takeoff and landing, VTOL)任务剖面下混动系统运行性能的相关研究。基于MATLAB Simulink,提出一种混合动力的协调方法,其中同时考虑两种操作模式。根据实际操作条件,预设垂直起降和平飞两种工况下不同的操作模式。在此基础上,研究作为主要电源的增程器调节功率流和提高增程器工作效率的电池协调。直流母线电压由DC/DC转换器调节,有利于电池组的整体寿命,实现了充电和放电状态期间的功率共享。仿真结果表明:可以很好地控制直流母线电压,并且增程器和电池之间的功率共享遵循设计。
文摘为优化燃料电池混合动力系统(fuel cell hybrid power system,FCHPS)并延长其使用寿命,该文提出一种考虑电堆性能一致性的多目标优化能量管理方法。该方法的目的是降低系统等效氢耗、提高燃料电池系统内电堆组运行效率的同时限制锂电池荷电状态(state of charge,SOC)波动。由于电堆组的性能会在实际运行过程中发生退化,因此该方法还考虑了电堆组的性能状态差异,通过限制性能较差电堆的运行压力,以延长系统寿命。为实现这一目的采用樽海鞘群算法(salpswarmalgorithm,SSA)对目标函数进行优化求解,得到系统最优功率分配。最后,基于RT-LAB半实物仿真平台,将所提方法与有限状态机控制方法进行对比,实验结果表明所提出的方法能够有效降低系统氢耗,提高电堆组效率的同时减缓性能较差电堆的功率波动,维持系统一致性,有利于系统长期稳定运行。
文摘针对由周期任务和零星任务形成的实时混合任务集进行合理调度问题,文中提出了一种基于零松弛度边界公平(Boundary Fair until Zero Laxity,BFZL)的实时混合任务算法。该算法在改进边界公平(Improved Boundary Fair,I-BF)实时混合任务算法基础上,通过引入最小松弛度优先(Least Laxity First,LLF)算法中的松弛度参数来改进判定任务的优先级,并提出基于松弛度与启发式策略相结合的启发式算法改进任务的分配策略。实验结果表明,BFZL算法能够满足系统实时性,并达到了算法优化目的。通过数据对比分析可知,该算法相比于原始算法,零星任务的平均响应时间降低了约26%,上下文切换减少了约28%,迁移减少了约50%。该算法在调度开销方面也具有一定优势。
基金Project (No. 2006C11148) supported by the ScienceTechnology Project of Zhejiang Province, China
文摘The primary focus of this study is to investigate the control strategies of a hybrid system used in hydraulic excavators. First, the structure and evaluation target of hybrid hydraulic excavators are analyzed. Then the dynamic system model including batteries, motor and engine is built as the simulation environment to obtain control results. A so-called multi-work-point dynamic control strategy, which has both closed-loop speed PI (proportion integral) control and direct torque control, is proposed and studied in the simulation model. Simulation results indicate that the hybrid system with this strategy can meet the power demand and achieve better system stability and higher fuel efficiency.