航空学报 > 2009, Vol. 30 Issue (8): 1508-1514

基于最小二乘支持向量机的小型无人直升机悬停动态建模

方舟,李平,韩波,侯鑫

  

  1. 浙江大学 航空航天学院
  • 收稿日期:2008-06-16 修回日期:2009-05-25 出版日期:2009-08-25 发布日期:2009-08-25
  • 通讯作者: 李平

Modeling Hover Dynamics of Small-scale Unmanned Helicopter Based on Least Square Support Vector Machine

Fang Zhou, Li Ping, Han Bo, Hou Xin

  

  1. School of Aeronautics and Astronautics, Zhejiang University
  • Received:2008-06-16 Revised:2009-05-25 Online:2009-08-25 Published:2009-08-25
  • Contact: Li Ping

摘要:

小型无人直升机(SUH)是一类典型的非线性动态系统,由于其本质不稳定性,由开环辨识实验获得的数据通常是小样本的,使用传统黑箱辨识方法难以获得较好的辨识效果。提出一种利用支持向量机(SVM)对SUH悬停动态进行辨识建模的新方法。通过动力学机理分析和合理的简化,确定了模型的非线性回归形式,以及从低维输入空间到高维Hilbert特征空间的映射关系和相应的机理核函数,并应用最小二乘支持向量机(LS-SVM)训练获得SVM模型和对应的参数化非线性多输入多输出(MIMO)模型。利用实际飞行数据辨识得到的模型不仅具有良好的预报精度,而且显式表达了各状态变量之间以及输入与状态之间的耦合关系,便于非线性控制策略的设计。

关键词: 小型无人直升机, 支持向量机, 最小二乘方法, 核函数, 飞行动态, 辨识

Abstract:

The small-scale unmanned helicopter (SUH) is a typical nonlinear dynamical system whose identification experiments are difficult to implement due to its inherent instability. The data sampled is thus small and non-informative, causing a loss to the estimation performance of conventional blackbox identification methods. In this article, a new method based on support vector machine (SVM) is proposed to identify the flight dynamics of SUHs at hover. Priori knowledge is used to simplify the dynamics and determine the non-linear regression form of the model. The mapping relationship is therefore constructed from the primal input space to the highdimensional feature space, with the corresponding kernel function determined. Least aquare SVMs (LS-SVMs) are applied to compute the SVM models. The corresponding non-linear parametric models are obtained consequently, which express the internal couplings explicitly while showing high prediction accuracy, and are suitable for non-linear controller design.

Key words: small-scale unmanned helicopter, support vector machines, least square methods, kernel function, flight dynamics, identification

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