In this paper the geographical information system （GIS） is applied to earthquake and tsunami emergency work and an earthquake and tsunami emergency command system （ETECS） for seaside cities is developed which is c...In this paper the geographical information system （GIS） is applied to earthquake and tsunami emergency work and an earthquake and tsunami emergency command system （ETECS） for seaside cities is developed which is composed of a basic database and six subsystems. By employing this system, the responsible municipal departments can make rapid prediction before the occurrence of earthquake or tsunami, make commanding decisions concerning the disaster-fight during the disastrous event, and make rapid estimates of the casualties and economic losses. So that the government could conduct relief work in time and planning for future disaster reduction and prevention.展开更多
The output feedback active disturbance rejection control of a valve-controlled cylinder electro-hydraulic servo system is investigated in this paper.First,a comprehensive nonlinear mathematical model that encompasses ...The output feedback active disturbance rejection control of a valve-controlled cylinder electro-hydraulic servo system is investigated in this paper.First,a comprehensive nonlinear mathematical model that encompasses both matched and mismatched disturbances is formulated.Due to the fact that only position information can be measured,a linear Extended State Observer(ESO)is introduced to estimate unknown states and matched disturbances,while a dedicated disturbance observer is constructed to estimate mismatched disturbances.Different from the traditional observer results,the design of the disturbance observer used in this study is carried out under the constraint of output feedback.Furthermore,an output feedback nonlinear controller is proposed leveraging the aforementioned observers to achieve accurate trajectory tracking.To mitigate the inherent differential explosion problem of the traditional backstepping framework,a finite-time stable command filter is incorporated.Simultaneously,considering transient filtering errors,a set of error compensation signals are designed to counter their negative impact effectively.Theoretical analysis affirms that the proposed control strategy ensures the boundedness of all signals within the closed-loop system.Additionally,under the specific condition of only time-invariant disturbances in the system,the conclusion of asymptotic stability is established.Finally,the algorithm’s efficacy is validated through comparative experiments.展开更多
This paper is the first in a two-part series that introduces an easy-to-implement central command architecture for high-order autonomous unmanned aerial systems. This paper discusses the development and the second pap...This paper is the first in a two-part series that introduces an easy-to-implement central command architecture for high-order autonomous unmanned aerial systems. This paper discusses the development and the second paper presents the flight test results. As shown in this paper, the central command architecture consists of a central command block, an autonomous planning block, and an autonomous flight controls block. The central command block includes a staging process that converts an objective into tasks independent of the vehicle (agent). The autonomous planning block contains a non-iterative sequence of algorithms that govern routing, vehicle assignment, and deconfliction. The autonomous flight controls block employs modern controls principles, dividing the control input into a guidance part and a regulation part. A novel feature of high-order central command, as this paper shows, is the elimination of operator-directed vehicle tasking and the manner in which deconfliction is treated. A detailed example illustrates different features of the architecture.展开更多
This paper introduced the composing and frame on the Tianjin earthquake emergency command technical system.It introduced the central function and the technical target.It evaluated the emergency and the applying prospe...This paper introduced the composing and frame on the Tianjin earthquake emergency command technical system.It introduced the central function and the technical target.It evaluated the emergency and the applying prospect on the system.展开更多
In order to clarify the application advantages of shortwave communication technology in civil air defense command and communication system, this paper starts from the basic concept of civil air defense command and com...In order to clarify the application advantages of shortwave communication technology in civil air defense command and communication system, this paper starts from the basic concept of civil air defense command and communication system, clarifies the advantages of shortwave communication technology and the actual requirements of civil air defense command and communication system, and discusses the application method of short air wave communication technology in civil air defense command and communication system. The results show that the application efficiency of the short-wave communication technology in the civil air defense command and communication system can improve the working efficiency of correctly erecting the antenna ground line and choosing the appropriate communication frequency. Therefore, the short-wave communication technology can effectively improve the work efficiency of the civil air defense command and communication system, and has the promotion value.展开更多
文摘In this paper the geographical information system （GIS） is applied to earthquake and tsunami emergency work and an earthquake and tsunami emergency command system （ETECS） for seaside cities is developed which is composed of a basic database and six subsystems. By employing this system, the responsible municipal departments can make rapid prediction before the occurrence of earthquake or tsunami, make commanding decisions concerning the disaster-fight during the disastrous event, and make rapid estimates of the casualties and economic losses. So that the government could conduct relief work in time and planning for future disaster reduction and prevention.
基金supported by the National Key R&D Program of China(No.2021YFB2011300)the Special Funds Project for the Transformation of Scientific and Technological Achievements of Jiangsu Province,China(No.BA2023039)+1 种基金the National Natural Science Foundation of China(No.52075262)the Fundamental Research Funds for the Central Universities,China(No.30922010706).
文摘The output feedback active disturbance rejection control of a valve-controlled cylinder electro-hydraulic servo system is investigated in this paper.First,a comprehensive nonlinear mathematical model that encompasses both matched and mismatched disturbances is formulated.Due to the fact that only position information can be measured,a linear Extended State Observer(ESO)is introduced to estimate unknown states and matched disturbances,while a dedicated disturbance observer is constructed to estimate mismatched disturbances.Different from the traditional observer results,the design of the disturbance observer used in this study is carried out under the constraint of output feedback.Furthermore,an output feedback nonlinear controller is proposed leveraging the aforementioned observers to achieve accurate trajectory tracking.To mitigate the inherent differential explosion problem of the traditional backstepping framework,a finite-time stable command filter is incorporated.Simultaneously,considering transient filtering errors,a set of error compensation signals are designed to counter their negative impact effectively.Theoretical analysis affirms that the proposed control strategy ensures the boundedness of all signals within the closed-loop system.Additionally,under the specific condition of only time-invariant disturbances in the system,the conclusion of asymptotic stability is established.Finally,the algorithm’s efficacy is validated through comparative experiments.
文摘This paper is the first in a two-part series that introduces an easy-to-implement central command architecture for high-order autonomous unmanned aerial systems. This paper discusses the development and the second paper presents the flight test results. As shown in this paper, the central command architecture consists of a central command block, an autonomous planning block, and an autonomous flight controls block. The central command block includes a staging process that converts an objective into tasks independent of the vehicle (agent). The autonomous planning block contains a non-iterative sequence of algorithms that govern routing, vehicle assignment, and deconfliction. The autonomous flight controls block employs modern controls principles, dividing the control input into a guidance part and a regulation part. A novel feature of high-order central command, as this paper shows, is the elimination of operator-directed vehicle tasking and the manner in which deconfliction is treated. A detailed example illustrates different features of the architecture.
文摘This paper introduced the composing and frame on the Tianjin earthquake emergency command technical system.It introduced the central function and the technical target.It evaluated the emergency and the applying prospect on the system.
文摘In order to clarify the application advantages of shortwave communication technology in civil air defense command and communication system, this paper starts from the basic concept of civil air defense command and communication system, clarifies the advantages of shortwave communication technology and the actual requirements of civil air defense command and communication system, and discusses the application method of short air wave communication technology in civil air defense command and communication system. The results show that the application efficiency of the short-wave communication technology in the civil air defense command and communication system can improve the working efficiency of correctly erecting the antenna ground line and choosing the appropriate communication frequency. Therefore, the short-wave communication technology can effectively improve the work efficiency of the civil air defense command and communication system, and has the promotion value.
