Fast-Slow Co-advancing Optimizer: Toward Harmonious Adversarial Training of GAN
Lin Wang, Xiancheng Wang, Rui Wang, Zhibo Zhang, Minghang Zhao
TL;DR
GAN training remains unstable due to hyperparameter sensitivity in the dual-player setup. FSCO integrates Deep Deterministic Policy Gradient (DDPG) as an embedded agent to adapt the discriminator's step size in real time, using the relation $\eta_{FSCO-D}(t) = \eta_{D}(t) \times u(t)$ and a reward $Reward(t) = -|Gloss(t) - Dloss(t)|$ to align generator and discriminator learning. The method smooths the adversarial dynamics, expanding the stable hyperparameter region and reducing the need for manual tuning, as demonstrated on MNIST, ANIME, and Ganyu. However, some limitations persist, including occasional overfitting and failures at higher resolutions, indicating areas for refinement and scope for diffusion-model alternatives.
Abstract
Up to now, the training processes of typical Generative Adversarial Networks (GANs) are still particularly sensitive to data properties and hyperparameters, which may lead to severe oscillations, difficulties in convergence, or even failures to converge, especially when the overall variances of the training sets are large. These phenomena are often attributed to the training characteristics of such networks. Aiming at the problem, this paper develops a new intelligent optimizer, Fast-Slow Co-advancing Optimizer (FSCO), which employs reinforcement learning in the training process of GANs to make training easier. Specifically, this paper allows the training step size to be controlled by an agent to improve training stability, and makes the training process more intelligent with variable learning rates, making GANs less sensitive to step size. Experiments have been conducted on three benchmark datasets to verify the effectiveness of the developed FSCO.
