Ma Hao, Ding Feng, Wang Yan
Key Laboratory of Advanced Process Control for Light Industry (Ministry of Education), School of Internet of Things Engineering, Jiangnan University, Wuxi 214122, PR China.
Key Laboratory of Advanced Process Control for Light Industry (Ministry of Education), School of Internet of Things Engineering, Jiangnan University, Wuxi 214122, PR China; School of Electrical and Electronic Engineering, Hubei University of Technology, Wuhan 430068, PR China.
ISA Trans. 2022 Nov;130:343-359. doi: 10.1016/j.isatra.2022.03.006. Epub 2022 Mar 17.
For the regression problem of support vector machine, the solution processes of the most existing methods use offline datasets, which cannot be realized online. For this problem, this paper presents a new online approach to identify these unknown parameters contained in the support vector machine. A new cost function is constructed by substituting the error term into the standard cost function, which is different from the standard support vector machine, and the gradient descent approach is then used to minimize the newly created loss function, thus proposing a stochastic gradient support vector machine algorithm to estimate the unknown parameters based on the recursive identification methods. Furthermore, to advance the property of the stochastic gradient support vector machine algorithm, a moving data window is used to widen the scalar information into a fixed-length innovation vector, thereby increasing the amount of information used in the parameter estimation based on the multi-innovation identification theory. In addition, the forgetting factor is brought into the proposed algorithms, and the corresponding forgetting factor recursive algorithms are derived. These methods are recursive identification methods, which may be implemented online and are more efficient in terms of computing. Finally, utilizing the MatLab platform, the validity and usefulness of the explored methodologies are proven using several numerical simulation examples.
对于支持向量机的回归问题,大多数现有方法的求解过程使用离线数据集,无法在线实现。针对该问题,本文提出一种新的在线方法来识别支持向量机中包含的这些未知参数。通过将误差项代入标准代价函数构造一个新的代价函数,这与标准支持向量机不同,然后使用梯度下降法来最小化新创建的损失函数,从而提出一种基于递归辨识方法估计未知参数的随机梯度支持向量机算法。此外,为了提升随机梯度支持向量机算法的性能,使用移动数据窗口将标量信息扩展为固定长度的新息向量,从而基于多新息辨识理论增加参数估计中使用的信息量。另外,将遗忘因子引入所提出的算法中,并推导了相应的遗忘因子递推算法。这些方法是递归辨识方法,可以在线实现且计算效率更高。最后,利用MatLab平台,通过几个数值仿真例子验证了所探索方法的有效性和实用性。