This paper focuses on the development of an embedded integrated servo-controller （EISC） for servomotors. Comprising of mainly servo-controller and servo-amplifiers, this EISC is capable of controlling a wide range o...This paper focuses on the development of an embedded integrated servo-controller （EISC） for servomotors. Comprising of mainly servo-controller and servo-amplifiers, this EISC is capable of controlling a wide range of servomotors to perform complieated tasks. Hence, integration of this EISC with a servomotor forms an intelligent modular actuator （IMA） that is essential to modern manufacturing industries. The development of such an EISC involves two major tasks： first, designing the hardware of a compact-sized and highly compatible EISC, and second, developing the software functions to facilitate its functionalities and capahilities. The developed EISC hence forms an integrated-servo-eontrol module, which determines the capability, functionality, flexibility and responsiveness of these IMAs.展开更多
Modular Unmanned Aerial Vehicles(UAVs)can adapt to rapidly changing payload requirements based on the shape and weight of the load by adding or subtracting units,reconfiguring,or changing the type of units.The existin...Modular Unmanned Aerial Vehicles(UAVs)can adapt to rapidly changing payload requirements based on the shape and weight of the load by adding or subtracting units,reconfiguring,or changing the type of units.The existing research has addressed aerial docking and hover control post-docking but fails to achieve coordinated flight following combination,leading to delayed response and oscillations as the number of UAV units increases.Moreover,the configuration of modular UAVs is complex and variable,making it challenging to adjust the controller parameters of each unit online.Therefore,this paper presents:(A)Adaptive attitude allocation method for different combined UAV configurations:establishing a mapping relationship between constant controller parameters of the unit and the combination angular acceleration.The desired torque of the combination is allocated based on the size of the lever arm,enabling adaptive attitude control of the combination for varying configurations by controlling the attitude of the local unit;(B)A power allocation strategy based on a leader-wingman mode:employing a leader to control the entire combination,distributing the combination’s force and torque to wingman units according to the mapping relationship of the attitude allocation method.This transforms the complex control of the combination into unit control in the leader-wingman mode.Compared to current average allocation methods,the step response of attitude angle improves by about 60% on average,and spatial trajectory tracking increases by an average of 11.5%.As the number of units grows,the response of the combination becomes similar to that of a single,independently flying UAV,resolving the oscillation issue in combined flight.Additionally,this approach eliminates the need to change the controller parameters of all units,facilitating convenient reconfiguration and coordinated flight for modular UAVs post-combination.展开更多
Based on the comparison of existing power flow controllers(PFC)in meshed HVDC grids,the full-bridge modular multilevel converter based PFC(MMPFC)is proposed.At first,the general branch current calculation method of me...Based on the comparison of existing power flow controllers(PFC)in meshed HVDC grids,the full-bridge modular multilevel converter based PFC(MMPFC)is proposed.At first,the general branch current calculation method of meshed HVDC grids with the PFC is presented,and then,the issue of over-voltage on the thyristor based PFC is described and analyzed.Through the analysis of different operating modes of the full-bridge sub-module,the mechanism of over-voltage ride through of the MMPFC is indicated.The control strategy of the MMPFC,which is used to control branch current and keep capacitor voltage balancing,is elaborated.Finally,the performance on current regulation,bidirectional operation and over-voltage ride through is simulated and verified in a built model with PSCAD/EMTDC.展开更多
This paper is a sequel to a previous publication by the same authors, in which an efficient modular solution to a robust supervisory control problem for discrete event systems modeled by finite automata with prefix-cl...This paper is a sequel to a previous publication by the same authors, in which an efficient modular solution to a robust supervisory control problem for discrete event systems modeled by finite automata with prefix-closed specification languages has been presented. This solution is based on a general recursive robust control scheme, which has been successfully applied to a number of problems. The additional contributions of the present paper are： （a） a slight generalization of the problem assumptions; （b） an alternative derivation of some of the results and an alternative formulation of the controller; （c） a detailed description of a very efficient on-line implementation algorithm; and （d） an illustrative practical example.展开更多
基金Supported by the High Technology Research and Development Programme of China （No.2002AA421160） and the National Natural Science Foundation of China （No.50375008）.
文摘This paper focuses on the development of an embedded integrated servo-controller （EISC） for servomotors. Comprising of mainly servo-controller and servo-amplifiers, this EISC is capable of controlling a wide range of servomotors to perform complieated tasks. Hence, integration of this EISC with a servomotor forms an intelligent modular actuator （IMA） that is essential to modern manufacturing industries. The development of such an EISC involves two major tasks： first, designing the hardware of a compact-sized and highly compatible EISC, and second, developing the software functions to facilitate its functionalities and capahilities. The developed EISC hence forms an integrated-servo-eontrol module, which determines the capability, functionality, flexibility and responsiveness of these IMAs.
基金supported by the Funding of National Key Laboratory of Rotorcraft Aeromechanics,China(No.61422202108)the National Natural Science Foundation of China(No.52176009)the Postgraduate Research&Practice Innovation Program of NUAA,China(No.xcxjh20220214).
文摘Modular Unmanned Aerial Vehicles(UAVs)can adapt to rapidly changing payload requirements based on the shape and weight of the load by adding or subtracting units,reconfiguring,or changing the type of units.The existing research has addressed aerial docking and hover control post-docking but fails to achieve coordinated flight following combination,leading to delayed response and oscillations as the number of UAV units increases.Moreover,the configuration of modular UAVs is complex and variable,making it challenging to adjust the controller parameters of each unit online.Therefore,this paper presents:(A)Adaptive attitude allocation method for different combined UAV configurations:establishing a mapping relationship between constant controller parameters of the unit and the combination angular acceleration.The desired torque of the combination is allocated based on the size of the lever arm,enabling adaptive attitude control of the combination for varying configurations by controlling the attitude of the local unit;(B)A power allocation strategy based on a leader-wingman mode:employing a leader to control the entire combination,distributing the combination’s force and torque to wingman units according to the mapping relationship of the attitude allocation method.This transforms the complex control of the combination into unit control in the leader-wingman mode.Compared to current average allocation methods,the step response of attitude angle improves by about 60% on average,and spatial trajectory tracking increases by an average of 11.5%.As the number of units grows,the response of the combination becomes similar to that of a single,independently flying UAV,resolving the oscillation issue in combined flight.Additionally,this approach eliminates the need to change the controller parameters of all units,facilitating convenient reconfiguration and coordinated flight for modular UAVs post-combination.
基金supported by the National High Technology Research and Development Program of China("863"Program)(Grant No.2012AA050205)
文摘Based on the comparison of existing power flow controllers(PFC)in meshed HVDC grids,the full-bridge modular multilevel converter based PFC(MMPFC)is proposed.At first,the general branch current calculation method of meshed HVDC grids with the PFC is presented,and then,the issue of over-voltage on the thyristor based PFC is described and analyzed.Through the analysis of different operating modes of the full-bridge sub-module,the mechanism of over-voltage ride through of the MMPFC is indicated.The control strategy of the MMPFC,which is used to control branch current and keep capacitor voltage balancing,is elaborated.Finally,the performance on current regulation,bidirectional operation and over-voltage ride through is simulated and verified in a built model with PSCAD/EMTDC.
基金Supported by the General Secretariat for Research and Technology, International Cooperation, Eureka Project (Grant No. E!3219-AADSS, EU)
文摘This paper is a sequel to a previous publication by the same authors, in which an efficient modular solution to a robust supervisory control problem for discrete event systems modeled by finite automata with prefix-closed specification languages has been presented. This solution is based on a general recursive robust control scheme, which has been successfully applied to a number of problems. The additional contributions of the present paper are： （a） a slight generalization of the problem assumptions; （b） an alternative derivation of some of the results and an alternative formulation of the controller; （c） a detailed description of a very efficient on-line implementation algorithm; and （d） an illustrative practical example.
