说明：  Vondrak滤波是由J.Vondrak于1967年提出，并在1976年进行了改进。其准则函数不仅包含与观测值残差有关的部分（观测部分），还包含与观测值无关的部分（非观测部分）。Vondrak滤波可以在未知观测资料的变化规律且未知其拟合函数的情况下，就能够对观测资料进行有效的平滑，因此在许多领域都得到了广泛的应用。
(Vondrak filter was proposed by J. Vondrak in 1967 and improved in 1976. The criterion function includes not only the observed part but also the non observed part. Vondrak filter can smooth the observed data effectively when the change law of observation data and its fitting function are unknown. Therefore, it has been widely used in many fields.)