In this paper, sensitivity approaches are taken to analyze and design an integrated flight propulsion control system where the interaction between subsystems direitly affects the stability property and handling perfor...In this paper, sensitivity approaches are taken to analyze and design an integrated flight propulsion control system where the interaction between subsystems direitly affects the stability property and handling performances of the aircraft. The eigenvalue sen sitivity approach is employed to study the effect of coupling parameters on system stability and gain sensitivity approach is used to direct the reduced states feedback suboptimal control system design. Simulation results show that the integrated flight propulsion control system designed by sensitivity approaches is of good performance.展开更多
A study is under way to apply the main power conversion element of the C/I device,the propulsion control unit of variable voltage and variable frequency(VVVF),to the electric vehicle by changing it from gate turn off ...A study is under way to apply the main power conversion element of the C/I device,the propulsion control unit of variable voltage and variable frequency(VVVF),to the electric vehicle by changing it from gate turn off thyristor(GTO)to insulated gate bipolar transistor(IGBT).In an early study,a combination of GTO and IGBT was tested on electric vehicles.The IGBT method was applied to 1 coach and the GTO method was applied to the remaining coaches.As a result of the test,a lack of traction force occurred due to an imbalance in output current.This phenomenon was determined to be caused by differences in the operational characteristics of the two types of power devices.This is due to the different response performance of the IGBT inverter vehicle and switching signal of the controller that drives the existing GTO inverter.When two power devices are used in a train,it is necessary to match the response performance between coaches.Interface board was manufactured and installed on the coach with IGBT and tested.The interface board is designed to have the characteristics of matching signals between the controller and the gate drive unit(GDU).As a result,the same switching response performance was achieved between GTO type and IGBT type coaches.The performance of using a mix of two power devices was verified.Therefore,normal driving performance and comfortable ride were maintained during the operation of the train.展开更多
The real-time capability of integrated flight/propulsion optimal control （IFPOC） is studied. An appli- cation is proposed for IFPOC by combining the onboard hybrid aero-engine model with sequential quadratic pro- gr...The real-time capability of integrated flight/propulsion optimal control （IFPOC） is studied. An appli- cation is proposed for IFPOC by combining the onboard hybrid aero-engine model with sequential quadratic pro- gramming （SQP）. Firstly, a steady-state hybrid aero-engine model is designed in the whole flight envelope with a dramatic enhancement of real-time capability. Secondly, the aero-engine performance seeking control including the maximum thrust mode and the minimum fuel-consumption mode is performed by SQP. Finally, digital simu- lations for cruise and accelerating flight are carried out. Results show that the proposed method improves real- time capability considerably with satisfactory effectiveness of optimization.展开更多
Over the past decade,the electric vehicle industry of China has developed rapidly,reaching one of the highest technological levels in the world.Nevertheless,most electric buses currently serve urban areas,being unsuit...Over the past decade,the electric vehicle industry of China has developed rapidly,reaching one of the highest technological levels in the world.Nevertheless,most electric buses currently serve urban areas,being unsuitable for all-climate operations.In response to the objective of massively adopting electric vehicles for transportation during all the events of the 2022 Beijing Winter Olympics,a dual-motor coaxial propulsion system for all-climate electric vehicles is proposed.The system aims to meet operating requirements such as high speed and adaptability to mountainous roads under severely cold environments.The system provides three operating modes,whose characteristics are analyzed under different conditions.In addition,dual-motor collaborative control strategy with collaborative gearshift and collaborative power distribution is proposed to eliminate power interruption during gearshift process and achieve intelligent power distribution,thus improving the gearshift quality and reducing energy consumption.Finally,gear position calibration for all-climate operation and proper gearshift is introduced.Experimental results demonstrate the advantages of the proposed dual-motor coaxial propulsion system regard-ing gearshift compared with the conventional single-motor automatic transmission.展开更多
Attributed to the miniaturized body size and active mobility,micro-and nanomotors(MNMs)have demonstrated tremendous potential for medical applications.However,from bench to bedside,massive efforts are needed to addres...Attributed to the miniaturized body size and active mobility,micro-and nanomotors(MNMs)have demonstrated tremendous potential for medical applications.However,from bench to bedside,massive efforts are needed to address critical issues,such as cost-effective fabrication,on-demand integration of multiple functions,biocompatibility,biodegradability,controlled propulsion and in vivo navigation.Herein,we summarize the advances of biomedical MNMs reported in the past two decades,with particular emphasis on the design,fabrication,propulsion,navigation,and the abilities of biological barriers penetration,biosensing,diagnosis,minimally invasive surgery and targeted cargo delivery.Future perspectives and challenges are discussed as well.This review can lay the foundation for the future direction of medical MNMs,pushing one step forward on the road to achieving practical theranostics using MNMs.展开更多
文摘In this paper, sensitivity approaches are taken to analyze and design an integrated flight propulsion control system where the interaction between subsystems direitly affects the stability property and handling performances of the aircraft. The eigenvalue sen sitivity approach is employed to study the effect of coupling parameters on system stability and gain sensitivity approach is used to direct the reduced states feedback suboptimal control system design. Simulation results show that the integrated flight propulsion control system designed by sensitivity approaches is of good performance.
基金This study was conducted by the Ministry of Land,Infrastructure and Transport’s Research Project on Railway Technology-Projects(20RTRP-C148759-03).
文摘A study is under way to apply the main power conversion element of the C/I device,the propulsion control unit of variable voltage and variable frequency(VVVF),to the electric vehicle by changing it from gate turn off thyristor(GTO)to insulated gate bipolar transistor(IGBT).In an early study,a combination of GTO and IGBT was tested on electric vehicles.The IGBT method was applied to 1 coach and the GTO method was applied to the remaining coaches.As a result of the test,a lack of traction force occurred due to an imbalance in output current.This phenomenon was determined to be caused by differences in the operational characteristics of the two types of power devices.This is due to the different response performance of the IGBT inverter vehicle and switching signal of the controller that drives the existing GTO inverter.When two power devices are used in a train,it is necessary to match the response performance between coaches.Interface board was manufactured and installed on the coach with IGBT and tested.The interface board is designed to have the characteristics of matching signals between the controller and the gate drive unit(GDU).As a result,the same switching response performance was achieved between GTO type and IGBT type coaches.The performance of using a mix of two power devices was verified.Therefore,normal driving performance and comfortable ride were maintained during the operation of the train.
基金Supported by the Aeronautical Science Foundation of China(2010ZB52011)the Funding of Jiangsu Innovation Program for Graduate Education(CXLX11-0213)the Nanjing University of Aeronautics and Astronautics Research Funding(NS2010055)~~
文摘The real-time capability of integrated flight/propulsion optimal control （IFPOC） is studied. An appli- cation is proposed for IFPOC by combining the onboard hybrid aero-engine model with sequential quadratic pro- gramming （SQP）. Firstly, a steady-state hybrid aero-engine model is designed in the whole flight envelope with a dramatic enhancement of real-time capability. Secondly, the aero-engine performance seeking control including the maximum thrust mode and the minimum fuel-consumption mode is performed by SQP. Finally, digital simu- lations for cruise and accelerating flight are carried out. Results show that the proposed method improves real- time capability considerably with satisfactory effectiveness of optimization.
基金This work was supported in part by the National Natural Science Foundation of China under Grant 51975049in part by the National Key Technology Research and Development Program of China under Grant 2017YFB0103801.
文摘Over the past decade,the electric vehicle industry of China has developed rapidly,reaching one of the highest technological levels in the world.Nevertheless,most electric buses currently serve urban areas,being unsuitable for all-climate operations.In response to the objective of massively adopting electric vehicles for transportation during all the events of the 2022 Beijing Winter Olympics,a dual-motor coaxial propulsion system for all-climate electric vehicles is proposed.The system aims to meet operating requirements such as high speed and adaptability to mountainous roads under severely cold environments.The system provides three operating modes,whose characteristics are analyzed under different conditions.In addition,dual-motor collaborative control strategy with collaborative gearshift and collaborative power distribution is proposed to eliminate power interruption during gearshift process and achieve intelligent power distribution,thus improving the gearshift quality and reducing energy consumption.Finally,gear position calibration for all-climate operation and proper gearshift is introduced.Experimental results demonstrate the advantages of the proposed dual-motor coaxial propulsion system regard-ing gearshift compared with the conventional single-motor automatic transmission.
基金supported by the National Natural Science Foundation of China(Grant No.22175083,51973241,82001845,52072095,92163109 and 22193033)。
文摘Attributed to the miniaturized body size and active mobility,micro-and nanomotors(MNMs)have demonstrated tremendous potential for medical applications.However,from bench to bedside,massive efforts are needed to address critical issues,such as cost-effective fabrication,on-demand integration of multiple functions,biocompatibility,biodegradability,controlled propulsion and in vivo navigation.Herein,we summarize the advances of biomedical MNMs reported in the past two decades,with particular emphasis on the design,fabrication,propulsion,navigation,and the abilities of biological barriers penetration,biosensing,diagnosis,minimally invasive surgery and targeted cargo delivery.Future perspectives and challenges are discussed as well.This review can lay the foundation for the future direction of medical MNMs,pushing one step forward on the road to achieving practical theranostics using MNMs.
