arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1504.08196eess.SYcs.SYstat.ML
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关于基于核的方法系统辨识中初始条件估计的问题

On the estimation of initial conditions in kernel-based system identification

ACCESS Linnaeus Center, School of Electrical Engineering, KTH Royal Institute of Technology(ACCESS林奈中心,电气工程学院,皇家理工学院)

Riccardo Sven Risuleo, Giulio Bottegal, Håkan Hjalmarsson

AI总结:

本文提出三种方法,利用不同类型的先验信息估计初始条件,并通过最大似然-后验估计器调整稳定样条核的超参数,通过期望最大化方法解决优化问题,提升了系统脉冲响应重建的准确性。

摘要:

近年来,系统辨识领域的发展引起了对正则化核方法的关注,其中采用最近引入的稳定样条核,强制施加对未知过程的先验信息。这降低了估计的方差,使得核方法在输入输出数据样本较少时特别有吸引力。然而,在这种情况下,系统初始条件的影响可能对输出动态产生显著影响。本文专门针对这一点,提出三种方法,利用不同类型的先验信息估计初始条件,并通过混合最大似然-后验估计器调整稳定样条核的超参数。为了解决相关优化问题,我们采用期望最大化方法,证明了解可以通过在简单更新步骤之间迭代获得。数值实验显示,与不考虑初始条件影响的其他核方法相比,所提策略在重建系统脉冲响应的准确性方面具有优势。

英文摘要:

Recent developments in system identification have brought attention to regularized kernel-based methods, where, adopting the recently introduced stable spline kernel, prior information on the unknown process is enforced. This reduces the variance of the estimates and thus makes kernel-based methods particularly attractive when few input-output data samples are available. In such cases however, the influence of the system initial conditions may have a significant impact on the output dynamics. In this paper, we specifically address this point. We propose three methods that deal with the estimation of initial conditions using different types of information. The methods consist in various mixed maximum likelihood--a posteriori estimators which estimate the initial conditions and tune the hyperparameters characterizing the stable spline kernel. To solve the related optimization problems, we resort to the expectation-maximization method, showing that the solutions can be attained by iterating among simple update steps. Numerical experiments show the advantages, in terms of accuracy in reconstructing the system impulse response, of the proposed strategies, compared to other kernel-based schemes not accounting for the effect initial conditions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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