A High-Precision Time Handling Library

An appropriate assessment of end-to-end network performance presumes highly efficient time tracking and measurement with precise time control of the stopping and resuming of program operation. In this paper, a novel approach to solving the problems of highly efficient and precise time measurements on PC-platforms and on ARM-architectures is proposed. A new unified High Performance Timer and a corresponding software library offer a unified interface to the known time counters and automatically identify the fastest and most reliable time source, available in the user space of a computing system. The research is focused on developing an approach of unified time acquisition from the PC hardware and accordingly substituting the common way of getting the time value through Linux system calls. The presented approach provides a much faster means of obtaining the time values with a nanosecond precision than by using conventional means. Moreover, it is capable of handling the sequential time value, precise sleep functions and process resuming. This ability means the reduction of wasting computer resources during the execution of a sleeping process from 100% （busy-wait） to 1-1.5%, whereas the benefits of very accurate process resuming times on long waits are maintained.     

一种智能变电站合并单元关键环节的实现方法

针对智能变电站中对合并单元时间性能指标上较高的技术要求,文中通过对由插值算法进行同步的合并单元实现原理的具体分析,充分利用PowerPC的计算能力和现场可编程门阵列(FPGA)的并行处理能力,将整个系统分成多个模块,并通过模块间的相互配合,提出一种具体的合并单元关键环节的设计方案。在该方案中,通过对连续有效秒脉冲间隔的统计和记录,来实现高精度的守时模块,并利用灵活设置的定时器中断周期,来对合并单元的重采样时刻进行动态调整,使之与外部对时信号同步。同时通过对输出延时的分解及FPGA的缓存功能,精确实现了SV9-2报文的等间隔输出。     

空间守时系统概念研究

针对太阳系广域时空尚没有统一时间的规则的问题,提出了一种新的统一时间的方法.空间守时系统坚守人类对时间的两个约定,即时间单位和时间起始点的约定,在基于广义相对论的空间计量理论的基础上,用铯原子钟测量原时,用脉冲星测量坐标时,用太阳系质心坐标系原点上的坐标时来统一时间.阐明了"标准时间不是唯一的"相对时间观,在不同局域坐...     

通用高精度时钟同步单元的设计方案

根据对时钟同步装置守时误差的分析,提出了一种通过降低测量误差进一步提高守时精度的同步时钟装置设计方案。该方案利用时钟内插方法降低全球定位系统(GPS)秒脉冲周期测量误差,对秒脉冲均值进行余数补偿消除均值计算中的引入误差,从而提高同步时钟装置的守时精度。根据所提方案设计了基于AMBA APB总线的通用高精度同步时钟知识产权(IP)核,并利用ARM Cortex-M0内核在现场可编程门阵列(FPGA)中构建了具有高精度同步时钟IP的片上系统(SoC)进行测试验证。测试结果表明,基于所提方案设计的通用高精度同步时钟IP核所生成的同步时钟精度在20 ns以内,守时误差在每小时300 ns以内。