A flight control system is designed for a reusable launch vehicle with aerodynamic control surfaces and reaction control system based on a variable-structure control and neural network theory.The control problems of c...A flight control system is designed for a reusable launch vehicle with aerodynamic control surfaces and reaction control system based on a variable-structure control and neural network theory.The control problems of coupling among the channels and the uncertainty of model parameters are solved by using the method.High precise and robust tracking of required attitude angles can be achieved in complicated air space.A mathematical model of reusable launch vehicle is presented first,and then a controller of flight system is presented.Base on the mathematical model,the controller is divided into two parts:variable-structure controller and neural network module which is used to modify the parameters of controller.This control system decouples the lateraldirectional tunnels well with a neural network sliding mode controller and provides a robust and de-coupled tracking for mission angle profiles.After this a control allocation algorithm is employed to allocate the torque moments to aerodynamic control surfaces and thrusters.The final simulation shows that the control system has a good accurate,robust and de-coupled tracking performance.The stable state error is less than 1°,and the overshoot is less than 5%.展开更多
After an introduction to the implementation of supervisory computer control (SCC) through networks and the relevant security issues, this paper centers on the core of network security design: intelligent front-end pro...After an introduction to the implementation of supervisory computer control (SCC) through networks and the relevant security issues, this paper centers on the core of network security design: intelligent front-end processor (FEP), encryption/decryption method and authentication protocol. Some other system-specific security measures are also proposed. Although these are examples only, the techniques discussed can also be used in and provide reference for other remote control systems.展开更多
[研究目的]从情报学和情报工作专业视角研究美国商务部工业与安全局(The Bureau of Industry and Secur-ity of U.S.Department of Commerce,BIS)的情报工作,为新时期中国情报学和情报工作创新发展提供参考。[研究方法]通过BIS官方网站...[研究目的]从情报学和情报工作专业视角研究美国商务部工业与安全局(The Bureau of Industry and Secur-ity of U.S.Department of Commerce,BIS)的情报工作,为新时期中国情报学和情报工作创新发展提供参考。[研究方法]通过BIS官方网站信息内容研究、官方网站重要文件研究、瓦森纳协定官方网站信息内容研究、BIS典型执法案例研究相结合的方法,研究BIS情报工作的全貌和精要。[研究结论]从情报学和情报工作专业视角对BIS的组织机构使命、组织网络、信息网络、人际网络、法律保障、典型情报工作、提升美国出口商情报能力的主要工作进行研究,揭示了BIS情报工作全貌、精要和最突出的关键成功因素。展开更多
In this article,an adaptive security control scheme is presented for cyber-physical systems(CPSs)suffering from false data injection(FDI)attacks and time-varying state constraints.Firstly,an adaptive bound estimation ...In this article,an adaptive security control scheme is presented for cyber-physical systems(CPSs)suffering from false data injection(FDI)attacks and time-varying state constraints.Firstly,an adaptive bound estimation mechanism is introduced in the backstepping control design to mitigate the effect of FDI attacks.Secondly,to solve the unknown sign time-varying statefeedback gains aroused by the FDI attacks,a type of Nussbaum function is employed in the adaptive security control.Then,by constructing a barrier Lyapunov function,it can be ensured that all signals of controlled system are bounded and the time-varying state constraints are not transgressed.Finally,the provided simulation examples demonstrate the effectiveness of the proposed controller.展开更多
文摘A flight control system is designed for a reusable launch vehicle with aerodynamic control surfaces and reaction control system based on a variable-structure control and neural network theory.The control problems of coupling among the channels and the uncertainty of model parameters are solved by using the method.High precise and robust tracking of required attitude angles can be achieved in complicated air space.A mathematical model of reusable launch vehicle is presented first,and then a controller of flight system is presented.Base on the mathematical model,the controller is divided into two parts:variable-structure controller and neural network module which is used to modify the parameters of controller.This control system decouples the lateraldirectional tunnels well with a neural network sliding mode controller and provides a robust and de-coupled tracking for mission angle profiles.After this a control allocation algorithm is employed to allocate the torque moments to aerodynamic control surfaces and thrusters.The final simulation shows that the control system has a good accurate,robust and de-coupled tracking performance.The stable state error is less than 1°,and the overshoot is less than 5%.
文摘After an introduction to the implementation of supervisory computer control (SCC) through networks and the relevant security issues, this paper centers on the core of network security design: intelligent front-end processor (FEP), encryption/decryption method and authentication protocol. Some other system-specific security measures are also proposed. Although these are examples only, the techniques discussed can also be used in and provide reference for other remote control systems.
文摘[研究目的]从情报学和情报工作专业视角研究美国商务部工业与安全局(The Bureau of Industry and Secur-ity of U.S.Department of Commerce,BIS)的情报工作,为新时期中国情报学和情报工作创新发展提供参考。[研究方法]通过BIS官方网站信息内容研究、官方网站重要文件研究、瓦森纳协定官方网站信息内容研究、BIS典型执法案例研究相结合的方法,研究BIS情报工作的全貌和精要。[研究结论]从情报学和情报工作专业视角对BIS的组织机构使命、组织网络、信息网络、人际网络、法律保障、典型情报工作、提升美国出口商情报能力的主要工作进行研究,揭示了BIS情报工作全貌、精要和最突出的关键成功因素。
基金Funds of National Science of China(Grant no.61973146,62173172,61833001)the Doctoral Research Initiation of Foundation of Liaoning Province(No.20180540047)the Distinguished Young Scientific Research Talents Plan in Liaoning Province(No.XLYC1907077,JQL201915402).
文摘In this article,an adaptive security control scheme is presented for cyber-physical systems(CPSs)suffering from false data injection(FDI)attacks and time-varying state constraints.Firstly,an adaptive bound estimation mechanism is introduced in the backstepping control design to mitigate the effect of FDI attacks.Secondly,to solve the unknown sign time-varying statefeedback gains aroused by the FDI attacks,a type of Nussbaum function is employed in the adaptive security control.Then,by constructing a barrier Lyapunov function,it can be ensured that all signals of controlled system are bounded and the time-varying state constraints are not transgressed.Finally,the provided simulation examples demonstrate the effectiveness of the proposed controller.
