共查询到20条相似文献,搜索用时 109 毫秒
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采用小波分解的分频段加权辨识方法 总被引:7,自引:1,他引:6
1 引言近年来,有关控制的辨识(Control-RelevantIdentification,CRID)逐渐受到了重视[1~3],辨识与控制之间的配合问题向传统辨识方法提出了新的要求.正如L.Ljung曾经指出[4]:真实系统与数学模型是两种不同的东西,模型的可接受性应该是“实用性”,而不是“真实性”.然而对实用性的不同理解,导致了不同的模型评价准则.CRID问题的研究表明,传统的辨识方法很少考虑控制的特点,模型评价准则与控制系统设计的要求并不相符.比如文献[1,2]指出:模型的开环频率响应不需要在所有频段(甚至包括低频段)都很准确,只需在剪切频率附近或控制器的工… 相似文献
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采用Brent优化的核学习单步预测控制算法 总被引:3,自引:2,他引:1
针对非线性SISO系统, 提出一种基于核学习辨识模型的单步预测控制算法(kernel learning one-step-ahead predictive control, KLOPC). 通过KL辨识模型得到系统的一步超前预报值, 并引入输出反馈和偏差校正以克服模型失配等因素引起的预测误差, 以此构造一步加权预测控制性能指标, 然后采用Brent一维搜索方法求取控制律. 该方法无需任何相关的导数信息, 需调整的参数少, 求解效率高. 在一非线性液位系统的仿真研究表明了KLOPC优于整定的PID和其它基于KL模型的控制方法, 对噪声和扰动等均具有更好的鲁棒性和自适应性. 相似文献
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Modeling and Identification of Multirate Systems 总被引:1,自引:0,他引:1
Multirate systems are abundant in industry; for example, many soft-sensor design problems are related to modeling, parameter identification, or state estimation involving multirate systems. The study of multirate systems goes back to the early 1950s, and has become an active research area in systems and control. This paper briefly surveys the history of development in the area of multirate systems, and introduces some basic concepts and latest results on multirate systems, including a polynomial transformation technique and the lifting technique as tools for handling multirate systems, lifted state space models, parameter identification of dual-rate systems, how to determine fast single-rate models from dual-rate models and directly from dual-rate data, and a hierarchical identification method for general multirate systems. Finally, some further research topics for multirate systems are given. 相似文献
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多采样率系统的辨识问题综述 总被引:1,自引:0,他引:1
在多率采样系统中, 采样间隔不均匀. 本文综述了文献中有关多率采样系统的数学模型, 如线性周期时变模型、频域模型和连续状态空间模型等. 同时对相应的辨识方法, 如提升、频域方法、子空间辨识方法等, 也进行了全面的综述. 对多率采样系统辨识中存在的一些问题, 包括辨识模型的选择、一致性问题、带约束条件的辨识方法和辨识收敛性等, 也作了深入的讨论. 相似文献
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Accurate identification of the model parameters of the machining process based on on-line process data is a crucial prerequisite for its model-based control and diagnostics. A typical machining process generates multi-output and multirate data streams. Whereas various sensors provide in-process information about the process, many important process outcomes including product qualities can be only measured in postprocess manner. This paper proposes to improve the identification by using both in-process and postprocess data and by analyzing the identifiability of model parameters. The identification of the model parameters based on multirate output is formulated using the maximum-likelihood estimation and the Fisher information matrix for a multirate-sampled system is derived to study the identifiability of model parameters. A strategy is developed to improve accuracy and robustness of the model identification considering the identifiability. The proposed method is tested on two batches of multirate process data from the cylindrical grinding process. The test results demonstrate using both in-process and postprocess data improves the identifiability and the proposed identification strategy results in improved prediction performance. 相似文献
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多率系统Kalman滤波算法是多率采样系统中对多源观测进行融合的重要手段. 基于化工过程的多率采样特点, 给出了多率Kalman滤波算法, 分析了该算法在模型失配情况下的鲁棒性. 在给定的假设条件下, 通过对滤波误差变化规律的分析, 给出了多率Kalman滤波稳定与发散的基本判定方法. 针对一类典型系统, 推导出了滤波稳定与发散判据. 通过仿真对该判据进行了验证, 仿真结果表明所提出的滤波鲁棒性分析方法可以用于算法的实际应用. 相似文献
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Multirate sampled-data systems: computing fast-rate models 总被引:2,自引:2,他引:2
This paper studies identification of a general multirate sampled-data system. Using the lifting technique, we associate the multirate system with an equivalent linear time-invariant system, from which a fast-rate discrete-time system is extracted. Uniqueness of the fast-rate system, controllability and observability of the lifted system, and other related issues are discussed. The effectiveness is demonstrated through simulation and real-time implementation. 相似文献
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输入多采样率数字控制系统的同时极点配置 总被引:2,自引:0,他引:2
在利用提升(lifting)技术所构造出来的多采样率数字控制系统的线性时不变状态空间模型的基础上, 讨论l个被控对象通过输入多采样率数字控制系统的同时极点配置问题. 分别引入了解决这一问题的状态空间方法和多项式矩阵插值方法. 通过适当的变换, 将同时极点配置问题归结为一系列线性方程组的求解问题. 指出, 当系统的输入采样率满足一定条件时, 可以利用输入多采样率的输出静态反馈控制系统, 实现对l个被控对象的同时极点配置. 相似文献
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在非均匀采样系统辨识方法中, 通常利用重采样、数值积分等方法来处理非均匀采样数据, 所用模型多为连续有理分式传递函数, 在递推形式下非均匀采样对象又常局限于``数据缺失'的情况. 本文研究更为一般的异步非均匀采样的多变量系统, 采用连续时间状态空间模型描述, 推导了模型参数、参数梯度和系统状态之间的相互递推关系, 构成一种可变迭代间隔的递推辨识算法, 在每次输出采样点上仅更新模型中受当前采样数据影响的参数. 这种辨识方法可以适用于任意非均匀采样系统, 多采样率系统也可作为一种特例适用于本算法. 仿真结果表明, 所提的方法是可行有效的. 相似文献
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W. Gomm 《Mathematics and computers in simulation》1981,23(1):34-50
If stiff differential systems can be divided into stiff and nonstiff subsystems, each subsystem can be integrated with different step sizes. These methods are called multirate methods, and they have been successfully used in several practical problems, especially in real-time simulations.In this paper a new way to perform the stability analysis of multirate versions of linear multistep methods is presented. This stability analysis makes use of the multirate z-transform method. 相似文献
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永磁同步电机(Permanent Magnet Synchronous Motor,PMSM)具有响应快、高精度、高转矩比等诸多优点,同时无传感器控制策略研究能有效提高PMSM系统的简易性和鲁棒性。在分析EKF和多采样率数字控制系统的基础上,建立永磁同步电机输入多采样率EKF算法,将其用于转速估计。通过仿真和实时实验验证其算法在辨识精度及收敛稳定性方面均优于单采样率EKF算法,并和高频单采样率EKF有着一致的辨识效果,而多采样率EKF算法的数据量及运算量均小于高频单采样率EKF。 相似文献