arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2601.09474cs.LGmath.OC
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从最优控制视角出发的终端约束流基生成模型

Terminally constrained flow-based generative models from an optimal control perspective

School of Mathematical Sciences, Fudan University(复旦大学数学学院);Shanghai Key Laboratory of Contemporary Applied Mathematics(上海当代应用数学重点实验室);Department of Mathematics and Institute for Functional Intelligent Materials(数学系和功能智能材料研究所);National University of Singapore(新加坡国立大学)

Weiguo Gao, Ming Li, Qianxiao Li

AI总结:

TOCFlow从最优控制视角提出一种几何感知的采样方法,通过终端共动框架实现二阶曲率效应捕捉,提升约束满足性能。

摘要:

我们通过最优控制方法,解决如何利用预训练的流基生成模型从具有终端约束的分布中采样的问题。理论上,我们通过Hamilton-Jacobi-Bellman方程来表征价值函数,并推导出最优反馈控制作为关联Hamiltonian的最小值。我们证明,随着控制惩罚项的增加,受控过程会恢复参考分布,而当惩罚项消失时,终端法则会收敛到约束流形上的广义Wasserstein投影。算法上,我们引入了基于流模型的终端最优控制(TOCFlow),这是一种几何感知的采样时间引导方法,用于预训练的流。在终端共动参考轨迹的框架下求解控制问题,得到沿Riemannian梯度的闭合形式标量阻尼因子,能够捕捉二阶曲率效应而无需矩阵求逆。因此,TOCFlow在计算成本上与标准梯度引导相当,但能够匹配Gauss-Newton更新的几何一致性。我们在三个高维科学任务上评估了TOCFlow,涵盖了等式、不等式和全局统计约束,即达西流、受约束轨迹规划以及具有Kolmogorov频谱尺度的湍流快照生成。在所有设置中,TOCFlow在满足约束方面优于欧几里得引导和投影基线,同时保持参考模型的生成质量。

英文摘要:

We address the problem of sampling from terminally constrained distributions with pre-trained flow-based generative models through an optimal control formulation. Theoretically, we characterize the value function by a Hamilton-Jacobi-Bellman equation and derive the optimal feedback control as the minimizer of the associated Hamiltonian. We show that as the control penalty increases, the controlled process recovers the reference distribution, while as the penalty vanishes, the terminal law converges to a generalized Wasserstein projection onto the constraint manifold. Algorithmically, we introduce Terminal Optimal Control with Flow-based models (TOCFlow), a geometry-aware sampling-time guidance method for pre-trained flows. Solving the control problem in a terminal co-moving frame that tracks reference trajectories yields a closed-form scalar damping factor along the Riemannian gradient, capturing second-order curvature effects without matrix inversions. TOCFlow therefore matches the geometric consistency of Gauss-Newton updates at the computational cost of standard gradient guidance. We evaluate TOCFlow on three high-dimensional scientific tasks spanning equality, inequality, and global statistical constraints, namely Darcy flow, constrained trajectory planning, and turbulence snapshot generation with Kolmogorov spectral scaling. Across all settings, TOCFlow improves constraint satisfaction over Euclidean guidance and projection baselines while preserving the reference model's generative quality.

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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