主要内容

模型降阶

获得复杂模型的低阶逼近

使用低阶模型可以简化分析和控制设计。相对于高阶模型,较简单的模型也更容易理解和操作。当您线性化复杂的 Simulink® 或 Partial Differential Equation Toolbox™ 模型、互连模型元素或使用其他过程以生成对您的应用尤为有用的动态特性影响不太大的状态时,您可以获得高阶模型。使用 Control System Toolbox™ 软件,您可以获得普通 LTI 模型或大型稀疏 LTI 模型的低阶模型。

要获得低阶模型,您可以:

  • 使用 freqsepmodalsep 丢弃在特定频率范围或感兴趣区域之外的模式(极点)。

  • 使用各种方法和标准(如平衡截断和本征正交分解 (POD))计算 LTI 模型或稀疏 LTI 模型的低阶逼近。使用 reducespec 作为这些工作流的入口函数。

此外,您还可以通过使用 minrealsminrealxelim 等函数执行零极点对相消或消除低贡献状态来简化模型。

您还可以使用模型降阶器和实时编辑器中的模型降阶任务以交互方式减少模型阶数。

有关降低模型阶数的方法的详细信息,请参阅Model Reduction Basics

App

模型降阶器Reduce complexity of linear time-invariant (LTI) models

实时编辑器任务

模型降阶Reduce complexity of linear time-invariant (LTI) models in the Live Editor

函数

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minreal最小实现或零极点相消
sminrealEliminates structurally disconnected states, delays, and blocks
xelimEliminate states from state-space models (自 R2023b 起)
sminDAEReduce algebraic states in sparse state-space models while preserving sparsity (自 R2024b 起)
modalsepCompute modal decomposition (自 R2023b 起)
modalsumSum of modal components (自 R2023b 起)
stabsepStable-unstable decomposition
freqsepSlow-fast decomposition
reducespecCreate model order reduction specifications (自 R2023b 起)
processRun model order reduction algorithm (自 R2023b 起)
view (balanced)Plot state contributions when using balanced truncation method (自 R2023b 起)
getrom (balanced)Obtain reduced-order models when using balanced truncation method (自 R2023b 起)
view (ncf)Plot state contributions when using balanced truncation of normalized coprime factors method (自 R2023b 起)
getrom (ncf)Obtain reduced-order models when using balanced truncation of normalized coprime factors method (自 R2023b 起)
view (modal)Plot mode information when using modal truncation method (自 R2023b 起)
getrom (modal)Obtain reduced-order models when using modal truncation method (自 R2023b 起)
view (pod)Plot state contributions when using proper orthogonal decomposition (POD) method (自 R2024b 起)
getrom (pod)Obtain reduced-order models when using proper orthogonal decomposition method (自 R2024b 起)
view (frfit)Plot relative fit error between original and fitted model (自 R2025a 起)
getrom (frfit)Obtain reduced-order models when using frequency-response fitting method (自 R2025a 起)
view (zpk)Plot computed poles and zeros when using zero-pole truncation method (自 R2025a 起)
getrom (zpk)Obtain reduced-order models when using zero-pole truncation method (自 R2025a 起)
updateUpdate URV approximation given new snapshots for POD (自 R2024b 起)
getURObtain U and R factors from incremental proper orthogonal decomposition (自 R2024b 起)
svdCompute truncated SVD of state-data matrix (自 R2024b 起)
mergeCombine incremental proper orthogonal decomposition results (自 R2024b 起)
lsim计算动态系统对任意输入的时间响应仿真数据

对象

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BalancedTruncationBalanced truncation model order reduction (自 R2023b 起)
BalancedTruncationOptionsOptions for model order reduction with balanced truncation (自 R2023b 起)
NCFBalancedTruncationBalanced truncation of normalized coprime factors model order reduction specification (自 R2023b 起)
SparseBalancedTruncationSparse balanced truncation model order reduction object (自 R2023b 起)
SparseBalancedTruncationOptionsOptions for sparse model order reduction with balanced truncation method (自 R2023b 起)
ModalTruncationModal truncation model order reduction specification (自 R2023b 起)
ModalTruncationOptionsOptions for model order reduction with modal truncation (自 R2023b 起)
SparseModalTruncationSparse modal truncation model order reduction specification (自 R2023b 起)
SparseModalTruncationOptionsOptions for sparse model order reduction with modal truncation method (自 R2023b 起)
ProperOrthogonalDecompositionProper orthogonal decomposition model order reduction (自 R2024b 起)
ProperOrthogonalDecompositionOptionsOptions for model order reduction with proper orthogonal decomposition (自 R2024b 起)
incrementalPODIncremental Proper Orthogonal Decomposition (POD) (自 R2024b 起)
FrequencyResponseFittingSpecification for fitting low-order model to frequency response (自 R2025a 起)
FrequencyResponseFittingOptionsOptions for model order reduction with frequency response fitting (自 R2025a 起)
SparseZeroPoleTruncationReduce sparse models using zero-pole truncation (自 R2025a 起)
SparseZeroPoleTruncationOptionsOptions for model order reduction with zero-pole truncation (自 R2025a 起)

主题

模型简化工作流

LTI 模型降阶

稀疏 LTI 模型降阶

交互式工作流