Better torque performance and higher reliability have long been the focus of research for slotted limited-angle torque motors(LATMs),which are primarily used to position first-stage valves in electrohydraulic servosys...Better torque performance and higher reliability have long been the focus of research for slotted limited-angle torque motors(LATMs),which are primarily used to position first-stage valves in electrohydraulic servosystems.This paper presents a high reliability axial-flux slotted LATM with quasi-Halbach array for torque performance improvement including constant torque range(CTR)and output torque.Firstly,the structure with two sets of windings and the operation principle of the proposed slotted LATM is analyzed.Secondly,a brief design procedure is presented,the structure selections of open slot and double-stator single-rotor(DSSR)interior rotor with surface mounted quasi-Halbach permanent magnet(PM)array are illustrated,and the geometric parameters are optimized to obtain the optimal design of the proposed slotted LATM.Then,3-D finite-element method(FEM)is employed to compare the proposed slotted LATM with the conventional surface mounted PM slotted LATM in terms of cogging torque,no-load back EMF,and output torque,and the results show that the proposed LATM with quasi-Halbach array has a 10%improvement in output torque and a 25%improvement in CTR.Meanwhile,the flux linkages and torque performance of the two sets of windings under various conditions verify good magnetic isolation.Finally,prototypes of two different rotor types are manufactured and a series of experiments are performed to validate the analysis.展开更多
A review of 115 studies on Australian local area traffic management(LATM)schemes covers network planning,computer modelling,overall design considerations,the deployment of various traffic control devices,project evalu...A review of 115 studies on Australian local area traffic management(LATM)schemes covers network planning,computer modelling,overall design considerations,the deployment of various traffic control devices,project evaluation and numerous before and after case studies.However,no research has been published about the formulation of LATM policies and the processes involved that were formulated during the 1970s and 1980s and aimed at discouraging non-local through traffic in residential areas,improving road safety,and improving environmental amenity through physical devices.This paper develops a conceptual model of the interactions amongst institutions of government(state and local),organisations(national research institutes and universities),and civil society(the consulting industry,lobby groups and community action groups).The model is implemented through a series of unstructured interviews with key players involved with research and advocacy,capacity building,and state government policy makers that determined:who was responsible for the governance of LATM schemes?What were the respective roles of institutions and organisations in relation to the early formulation of policies and plans,especially issues of authority?Who were the key players in these institutions and organisations?To what extent did external influences of ideas by overseas agents(policy transfer)occur in decision making?A recently implemented LATM scheme(Seven Ways)by Waverley Council describes the latest approaches,including community participation.The conclusions note the importance of a society investing in road research,having universities capable of delivering high-quality professional development programs,and having a consulting industry that is willing to deliver innovative,practical advice to local governments.Suggestions are made about areas for further research.展开更多
基金supported in part by the National Nature Science Foundation of China(NSFC)under Project 52122705。
文摘Better torque performance and higher reliability have long been the focus of research for slotted limited-angle torque motors(LATMs),which are primarily used to position first-stage valves in electrohydraulic servosystems.This paper presents a high reliability axial-flux slotted LATM with quasi-Halbach array for torque performance improvement including constant torque range(CTR)and output torque.Firstly,the structure with two sets of windings and the operation principle of the proposed slotted LATM is analyzed.Secondly,a brief design procedure is presented,the structure selections of open slot and double-stator single-rotor(DSSR)interior rotor with surface mounted quasi-Halbach permanent magnet(PM)array are illustrated,and the geometric parameters are optimized to obtain the optimal design of the proposed slotted LATM.Then,3-D finite-element method(FEM)is employed to compare the proposed slotted LATM with the conventional surface mounted PM slotted LATM in terms of cogging torque,no-load back EMF,and output torque,and the results show that the proposed LATM with quasi-Halbach array has a 10%improvement in output torque and a 25%improvement in CTR.Meanwhile,the flux linkages and torque performance of the two sets of windings under various conditions verify good magnetic isolation.Finally,prototypes of two different rotor types are manufactured and a series of experiments are performed to validate the analysis.
文摘A review of 115 studies on Australian local area traffic management(LATM)schemes covers network planning,computer modelling,overall design considerations,the deployment of various traffic control devices,project evaluation and numerous before and after case studies.However,no research has been published about the formulation of LATM policies and the processes involved that were formulated during the 1970s and 1980s and aimed at discouraging non-local through traffic in residential areas,improving road safety,and improving environmental amenity through physical devices.This paper develops a conceptual model of the interactions amongst institutions of government(state and local),organisations(national research institutes and universities),and civil society(the consulting industry,lobby groups and community action groups).The model is implemented through a series of unstructured interviews with key players involved with research and advocacy,capacity building,and state government policy makers that determined:who was responsible for the governance of LATM schemes?What were the respective roles of institutions and organisations in relation to the early formulation of policies and plans,especially issues of authority?Who were the key players in these institutions and organisations?To what extent did external influences of ideas by overseas agents(policy transfer)occur in decision making?A recently implemented LATM scheme(Seven Ways)by Waverley Council describes the latest approaches,including community participation.The conclusions note the importance of a society investing in road research,having universities capable of delivering high-quality professional development programs,and having a consulting industry that is willing to deliver innovative,practical advice to local governments.Suggestions are made about areas for further research.
