Improving Feasibility via Fast Autoencoder-Based Projections

arXiv cs.LG / 4/7/2026

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Key Points

  • The paper tackles the challenge of efficiently enforcing complex, often nonconvex operational constraints in real-world learning and control systems.
  • It proposes a fast, data-driven amortized projection method that uses a trained autoencoder to approximate a projector, enabling quick feasibility corrections to otherwise infeasible neural outputs.
  • The approach trains the autoencoder with an adversarial objective to obtain a structured latent space where the feasible set is represented in a convex form, allowing simple convex projection in latent space.
  • At inference time, the method projects the latent representation onto the convex latent shape and then decodes back to the original space to produce corrected feasible predictions.
  • Experiments across constrained optimization and reinforcement learning benchmarks with hard nonconvex constraints indicate effective constraint enforcement with low computational cost versus traditional solver-based correction.

Abstract

Enforcing complex (e.g., nonconvex) operational constraints is a critical challenge in real-world learning and control systems. However, existing methods struggle to efficiently enforce general classes of constraints. To address this, we propose a novel data-driven amortized approach that uses a trained autoencoder as an approximate projector to provide fast corrections to infeasible predictions. Specifically, we train an autoencoder using an adversarial objective to learn a structured, convex latent representation of the feasible set. This enables rapid correction of neural network outputs by projecting their associated latent representations onto a simple convex shape before decoding into the original feasible set. We test our approach on a diverse suite of constrained optimization and reinforcement learning problems with challenging nonconvex constraints. Results show that our method effectively enforces constraints at a low computational cost, offering a practical alternative to expensive feasibility correction techniques based on traditional solvers.