可搬运钙离子光钟嵌入式控制系统实时性分析

Real-Time Performance Analysis of Embedded Control System for Transportable ^(40)Ca^(+)Ion Optical Clock

随着激光冷却技术、超窄线宽激光器和飞秒光学频率梳的飞速发展,目前实验室光钟的不确定度和稳定度都已经到了小系数10^(-18)水平。小型化、集成化可搬运光钟在下一代秒定义、引力势测量、高程差测量、地球固体潮汐测量等方面有自己独特的优势,光钟从实验室走向实际应用过程中,控制系统需要完成小型化及集成化设计,且性能指标不降低。在光钟运行过程中,控制系统延时造成的死时间会影响可搬运光钟的系统稳定性指标。为了降低死时间对光钟稳定性的影响,以Xilinx推出的zynq架构的芯片为处理核心搭建硬件平台,以嵌入式Linux系统为软件核心,设计了钙离子光钟嵌入式控制系统。从钙离子光钟嵌入式控制系统的中断实时性要求出发,分析了新设计的硬件平台对光钟运行时序延时的影响,经分析,控制系统对系统稳定度的影响在2×10^(-16)以下,可满足可搬运钙离子光钟对控制系统实时性的要求。

With the rapid development of laser cooling technology,ultra-narrow linewidth lasers,and femtosecond optical frequency combs,the uncertainty and stability of laboratory optical clocks have now reached a level of small coefficients of 10^(-18).Miniaturized,integrated,and portable optical clocks have unique advantages in next-generation"second"definitions,gravitational potential measurements,elevation difference measurements,and solid earth tide measurements.In the process of moving from the laboratory to practical applications,the control system needs to complete miniaturization and integration design without compromising performance indicators.During the operation of the optical clock,the dead time caused by the control system delay affects the system stability indicators of the transportable optical clock.To reduce the impact of dead time on the stability of the optical clock,a hardware platform is built using Xilinx's Zynq architecture chip as the processing core and embedded Linux system as the software core.An embedded control system for transportable ^(40)Ca^(+) ion optical clock is developed.Starting from the real-time interrupt requirements of the embedded control system of the ^(40)Ca^(+) ion optical clock,this paper analyzes the impact of the newly developed hardware platform on the timing delay during the operation of the optical clock.Through analysis,it is found that the impact of the control system on system stability is below 2×10^(-16),which can meet the real-time requirements of the control system for transportable ^(40)Ca^(+) ion optical clock.