During the non-landing measuring of vehicle mounted theodolite, especially under high-speed tracking measurement, the misalignment of theodolite's center of mass and spindle etc. will cause high-frequency vibratio...During the non-landing measuring of vehicle mounted theodolite, especially under high-speed tracking measurement, the misalignment of theodolite's center of mass and spindle etc. will cause high-frequency vibration of theodolite platform, increase the observation error of targets and even unbelievable results. In this paper, a correction method of non-landing measuring of theodolite based on static datum conversion is presented, which can effectively improve the observation accuracy of theodolite. The CCD camera is fixed to the theodolite platform to calculate the gesture shaking quantity of theodolite platform in geodetic coordinate system through the real time imaging of static datum. The observation results of theodolite are corrected by using such shaking quantity. The experiment shows that the correction accuracy exceeds 10 s of arc. The intrinsic parameter calibration technology of camera based on stellar angular distance and absolute conic put forward in this paper can prevent the estimated error of extrinsic parameters influencing the intrinsic parameter calibration and improve the intrinsic parameter calibration accuracy; the static datum conversion technology can reduce the influence of installation error of camera and theodolite platform on gesture measuring of the platform. The simulation experiment shows that when the shaking range of the platform is less than 30 min of arc, the influence of the three-axis installation error of camera within 3deg on the accuracy of correction results is less than 8 s of arc. The method in this paper can be extended to and used in the field of gesture shaking measuring and micro-structure deformation of various unstable platforms, therefore it is of important theoretical research significance and has wide engineering application prospect.展开更多
控制器局域网络(Controller Area Network)CAN-TSN(Time Sensitive Networking,时间敏感网络)网关是下一代车载网络架构中关键业务数据端到端传输路径上的重要环节,其实时性直接影响跨异构网络系统传输报文的可调度性。针对CAN-TSN网关...控制器局域网络(Controller Area Network)CAN-TSN(Time Sensitive Networking,时间敏感网络)网关是下一代车载网络架构中关键业务数据端到端传输路径上的重要环节,其实时性直接影响跨异构网络系统传输报文的可调度性。针对CAN-TSN网关实时性分析,现有研究存在网关处理延时组成要素不全、缺乏对TSN网络的调度规划结果的联合分析等亟待解决的问题,导致利用现有研究获取的可调度集往往无法满足端到端的截止时间约束。针对上述问题,提出一种基于联合规划的CAN-TSN网关实时性分析方法。该方法基于现有CAN-TSN网关架构设计构建通用框架,分析网关处理延时组成,获取处理延时的参数化模型;联合TSN网络的规划调度结果,推导满足报文端到端可调度性的网关延时上界;搭建CAN-TSN网关原型系统,使用真实车载CAN消息集进行可调度率分析。实验结果表明,基于联合规划的CAN-TSN网关实时性分析方法,能够收紧真实环境中CAN消息集的可调度范围,使得可调度率收紧约6.7%,同时能够对网关实时性架构优化起指导作用。展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 11072263 and 11272347)Program for New Century Talents in University
文摘During the non-landing measuring of vehicle mounted theodolite, especially under high-speed tracking measurement, the misalignment of theodolite's center of mass and spindle etc. will cause high-frequency vibration of theodolite platform, increase the observation error of targets and even unbelievable results. In this paper, a correction method of non-landing measuring of theodolite based on static datum conversion is presented, which can effectively improve the observation accuracy of theodolite. The CCD camera is fixed to the theodolite platform to calculate the gesture shaking quantity of theodolite platform in geodetic coordinate system through the real time imaging of static datum. The observation results of theodolite are corrected by using such shaking quantity. The experiment shows that the correction accuracy exceeds 10 s of arc. The intrinsic parameter calibration technology of camera based on stellar angular distance and absolute conic put forward in this paper can prevent the estimated error of extrinsic parameters influencing the intrinsic parameter calibration and improve the intrinsic parameter calibration accuracy; the static datum conversion technology can reduce the influence of installation error of camera and theodolite platform on gesture measuring of the platform. The simulation experiment shows that when the shaking range of the platform is less than 30 min of arc, the influence of the three-axis installation error of camera within 3deg on the accuracy of correction results is less than 8 s of arc. The method in this paper can be extended to and used in the field of gesture shaking measuring and micro-structure deformation of various unstable platforms, therefore it is of important theoretical research significance and has wide engineering application prospect.
文摘控制器局域网络(Controller Area Network)CAN-TSN(Time Sensitive Networking,时间敏感网络)网关是下一代车载网络架构中关键业务数据端到端传输路径上的重要环节,其实时性直接影响跨异构网络系统传输报文的可调度性。针对CAN-TSN网关实时性分析,现有研究存在网关处理延时组成要素不全、缺乏对TSN网络的调度规划结果的联合分析等亟待解决的问题,导致利用现有研究获取的可调度集往往无法满足端到端的截止时间约束。针对上述问题,提出一种基于联合规划的CAN-TSN网关实时性分析方法。该方法基于现有CAN-TSN网关架构设计构建通用框架,分析网关处理延时组成,获取处理延时的参数化模型;联合TSN网络的规划调度结果,推导满足报文端到端可调度性的网关延时上界;搭建CAN-TSN网关原型系统,使用真实车载CAN消息集进行可调度率分析。实验结果表明,基于联合规划的CAN-TSN网关实时性分析方法,能够收紧真实环境中CAN消息集的可调度范围,使得可调度率收紧约6.7%,同时能够对网关实时性架构优化起指导作用。
