PAWS: アドバンテージ重み付きセグメントを用いた選好学習
PAWS: Preference Learning with Advantage-Weighted Segments
人間の軌道比較から報酬を学習する選好ベース強化学習において、訓練と推論の不一致による分布シフトを分析し、セグメントレベルのアドバンテージ関数を直接用いた政策更新手法PAWSを提案した。ロボット操作・移動タスクで既存手法を上回る性能を示した。
著者: Aleksandar Taranovic, Onur Celik, Niklas Freymuth, Ge Li, Serge Thilges, Huy Le, Tai Hoang, Rania Rayyes, Gerhard Neumann
分類: cs.LG
原文アブストラクト
Preference-based reinforcement learning (PbRL) learns policies from human trajectory-level comparisons, avoiding explicit reward design and expert demonstrations. Existing methods typically train utility functions on trajectory or segment-level preferences while relying on per-step utility estimates during policy optimization. This training and inference mismatch induces a distribution shift that severely degrades temporal credit assignment and limits policy learning. We analyze this issue and propose PAWS, a segment-based preference learning method that performs policy updates directly using segment-level advantage functions. By aligning utility training with policy optimization, PAWS preserves trajectory-level preference information and avoids unreliable per-step learning signals. Experiments on simulated robotic manipulation and locomotion tasks demonstrate that PAWS consistently outperforms existing PbRL approaches, highlighting the importance of distribution-consistent preference learning.