以激光测速为基础, 引入飞秒光频梳, 通过鉴相信号处理, 研究出了一种高精度的测速方法, 理论测量下限低至μm/s量级。文中详细分析了飞秒光频梳经运动目标反射后梳齿相位发生变化的原理, 建立了较为全面的数学模型并使用MATLAB软件进行了仿真。采用快速傅里叶变换方法对仿真测量信号相位信息进行提取并处理, 分别对μm/s、mm/s和m/s量级速度值进行了测量, 理想情况下测量误差在1 μm/s以下。同时, 还对做任意运动的目标进行了测量仿真实验, 结果表明文中方法还可以还原目标的运动状态。最后搭建了实验装置对mm/s量级的速度进行测量, 测量相对误差均在4%以内, 验证了此方法的可行性。

Based on laser speed measurement, a method for high-accuracy speed measurement was developed by using femtosecond optical frequency comb based on the phase signal processing. The low speed measurement limit is μm/s level theoretically. The principle of phase changing was analyzed in detail, and a comprehensive model was established and simulated with MATLAB. The phase information of simulated measurement signals were processed by fast Fourier transform, and the speeds of μm/s, mm/s and m/s were measured respectively. Ideally, the measurement error was below 1 μm/s. In addition, arbitrary movement targets can be measured through the model. The movement state of target was restored with this method. The experiment was conducted to measure the speed of mm/s, and the relative errors were all within 4%. The results show that high-accuracy speed measurement can be achieved by using this method.