A Beidou 3(BD3)system-based power reference station can provide high-precision time synchronization for power distribution systems by sending synchronization data packets to devices in a multi-hop routing fashion.Howe...A Beidou 3(BD3)system-based power reference station can provide high-precision time synchronization for power distribution systems by sending synchronization data packets to devices in a multi-hop routing fashion.However,optimizing route selection to reduce both time synchronization error and delay is a challenging problem.In this paper,we establish a software-defined network-enabled power reference station time synchronization framework based on BD3.Then,we formulate the joint problem to minimize cumulative synchronization error and delay through multi-hop route selection optimization.A back propagation(BP)neural network-improved intelligent time synchronization route selection algorithm named BP-RS is proposed to learn the optimal route selection,which uses a BP neural network to dynamically adjust the exploration factor to achieve rapid convergence.Simulation results show the superior performance of BP-RS in synchronization delay,synchronization error,and adaptability with changing routing topologies.展开更多
Real-time kinematic GPS precise positioning has been playing an increasing role in both surveying and navigation. Based on the city’s fibre LAN network, Shenzhen Continuous Operating Reference Stations (SZCORS) syste...Real-time kinematic GPS precise positioning has been playing an increasing role in both surveying and navigation. Based on the city’s fibre LAN network, Shenzhen Continuous Operating Reference Stations (SZCORS) system has been established and consists of GPS reference stations, system control center, user’s data center, and real-time datacom network. The SZCORS system provides users the real-time centimeter positioning or post-processing millimeter positioning. This paper makes discussion on the structure of SZCORS system. Some experiments have been made to test the usablity, and then the data has been analyzed.展开更多
A high precision method used for on-spot calibration of distributed stereoreference position setting is presented. The high measuring accuracy in stereo reference calibrationis derived from using a high precision wate...A high precision method used for on-spot calibration of distributed stereoreference position setting is presented. The high measuring accuracy in stereo reference calibrationis derived from using a high precision water level instrument and an accurate height verniercaliper. It settles the problem of reference calibration effectively and accurately, without usinglarge coordinate measuring machines (CMM). It is more adaptable and precise than traditionalcalibration methods applying theodolites or autocollimators. The error sources of this method areanalyzed in detail and several methods are developed to eliminate the calibration error.Anoptimizing swallowtail-like anchor target is developed. Experiments show that the calibrationaccuracy can be limited within 0.06 mm in the range of 3～5 m and 0.03 mm with optimizing anchortarget. This method can be widely used in on-spot calibration.展开更多
Network RTK (Real-Time Kinematic) is a technology that is based on GPS (Global Positioning System) or more gener-ally on GNSS (Global Navigation Satellite System) measurements to achieve centimeter-level accuracy posi...Network RTK (Real-Time Kinematic) is a technology that is based on GPS (Global Positioning System) or more gener-ally on GNSS (Global Navigation Satellite System) measurements to achieve centimeter-level accuracy positioning in real-time. Reference station placement is an important problem in the design and deployment of network RTK systems as it directly affects the quality of the positioning service and the cost of the network RTK systems. This paper identifies a new reference station placement for network RTK, namely QoS-aware regional network RTK reference station placement problem, and proposes an algorithm for the new reference station placement problem. The algorithm can always produce a reference station placement solution that completely covers the region of network RTK.展开更多
The factual data on error of positioning in VRS GPS networks have been analyzed, where the mobile receiver is provided with VRS. The method of highly informative zone is suggested for removal of initial vagueness in s...The factual data on error of positioning in VRS GPS networks have been analyzed, where the mobile receiver is provided with VRS. The method of highly informative zone is suggested for removal of initial vagueness in selection of reference stations for purposes of development of VRS on the basis of minimum GPS network, composed of three reference stations. The recommendations on use of suggested method are given.展开更多
基金supported by the Science and Technology Project of the China Southern Power Grid Company Limited under grant number GDKJXM20202032。
文摘A Beidou 3(BD3)system-based power reference station can provide high-precision time synchronization for power distribution systems by sending synchronization data packets to devices in a multi-hop routing fashion.However,optimizing route selection to reduce both time synchronization error and delay is a challenging problem.In this paper,we establish a software-defined network-enabled power reference station time synchronization framework based on BD3.Then,we formulate the joint problem to minimize cumulative synchronization error and delay through multi-hop route selection optimization.A back propagation(BP)neural network-improved intelligent time synchronization route selection algorithm named BP-RS is proposed to learn the optimal route selection,which uses a BP neural network to dynamically adjust the exploration factor to achieve rapid convergence.Simulation results show the superior performance of BP-RS in synchronization delay,synchronization error,and adaptability with changing routing topologies.
文摘Real-time kinematic GPS precise positioning has been playing an increasing role in both surveying and navigation. Based on the city’s fibre LAN network, Shenzhen Continuous Operating Reference Stations (SZCORS) system has been established and consists of GPS reference stations, system control center, user’s data center, and real-time datacom network. The SZCORS system provides users the real-time centimeter positioning or post-processing millimeter positioning. This paper makes discussion on the structure of SZCORS system. Some experiments have been made to test the usablity, and then the data has been analyzed.
基金This project is supported by 863 Program Committee of China (No. 863-512-9804-11).
文摘A high precision method used for on-spot calibration of distributed stereoreference position setting is presented. The high measuring accuracy in stereo reference calibrationis derived from using a high precision water level instrument and an accurate height verniercaliper. It settles the problem of reference calibration effectively and accurately, without usinglarge coordinate measuring machines (CMM). It is more adaptable and precise than traditionalcalibration methods applying theodolites or autocollimators. The error sources of this method areanalyzed in detail and several methods are developed to eliminate the calibration error.Anoptimizing swallowtail-like anchor target is developed. Experiments show that the calibrationaccuracy can be limited within 0.06 mm in the range of 3～5 m and 0.03 mm with optimizing anchortarget. This method can be widely used in on-spot calibration.
文摘Network RTK (Real-Time Kinematic) is a technology that is based on GPS (Global Positioning System) or more gener-ally on GNSS (Global Navigation Satellite System) measurements to achieve centimeter-level accuracy positioning in real-time. Reference station placement is an important problem in the design and deployment of network RTK systems as it directly affects the quality of the positioning service and the cost of the network RTK systems. This paper identifies a new reference station placement for network RTK, namely QoS-aware regional network RTK reference station placement problem, and proposes an algorithm for the new reference station placement problem. The algorithm can always produce a reference station placement solution that completely covers the region of network RTK.
文摘The factual data on error of positioning in VRS GPS networks have been analyzed, where the mobile receiver is provided with VRS. The method of highly informative zone is suggested for removal of initial vagueness in selection of reference stations for purposes of development of VRS on the basis of minimum GPS network, composed of three reference stations. The recommendations on use of suggested method are given.
