双飞秒激光绝对距离测量系统具有测量精度高、更新速率快的优点, 然而测量过程中的高斯白噪声会造成测距精度的降低。提出了一种基于卡尔曼滤波技术的提高双飞秒激光绝对距离测量精度的方法, 即通过建立卡尔曼滤波状态空间模型得到测量结果的最优状态估计, 大幅度降低随机过程引入的测量精度损失, 同时可以得到速度信息估计值。实验结果表明, 目标静止时卡尔曼滤波技术可将测量标准差降低近一个数量级; 目标匀速运动时, 稳定状态下三维状态空间模型估计的速度标准差约4 μm/s。

The absolute distance measurement system based on dual femtosecond lasers has the advantages of high measurement precision and high update rate. However, the effect of white Gaussian noises during the measurement will result in the decrease of measurement precision. The method based on Kalman filtering technique is proposed to improve the absolute distance measurement precision based on dual femtosecond lasers. The Kalman filtering state space model is established to obtain the optimal state estimation of the distance measurement results, which can greatly reduce the measurement precision loss introduced by the stochastic process and meanwhile output the optimal estimated speed value. The experimental results show that the standard deviation of the distance measurement is reduced by nearly an order of magnitude by using the Kalman filtering technique when the target is in a statistic state. The standard deviation of the estimated speed is about 4 μm/s when the target is moving at a uniform speed.