改进视觉世界模型的路径感知规划,提升复杂任务成功率
Traj-LeWM: Path-Aware World-Model Planning via Latent Trajectory Cost

- 引入轨迹级成本函数,融合路径全程信息优化模型表征
- 在4个任务上相比原模型提升3%~14%,最高提升14个百分点
- 适合需要精确路径规划的强化学习与机器人控制场景
LeWM是一种轻量级视觉世界模型,通过端到端从像素中学习潜在动态,并根据预测终点与目标的距离对候选动作序列进行排序。然而,LeWM存在两个局限:训练时仅学习局部下一步转移,未评估完整轨迹与任务目标的关系;规划时仅依据终点距离排序。由于模型预测与实际执行可能存在偏差,预测终点最接近目标的候选动作未必在环境中表现最佳。因此,完整预测轨迹的演化过程可提供超越终点距离的补充信息。为此,本文提出Traj-LeWM,保留LeWM的局部动态目标和终点评分,新增一种目标条件的潜在轨迹成本(LTC),在训练阶段以轨迹偏好监督补充下一步预测,共同塑造共享表征;在规划阶段将LTC与终点距离联合使用,融入中间路径信息进行候选排序。联合终点+LTC评分使Traj-LeWM在Push-T、OGBench-Cube、Reacher和Two-Room任务上分别取得3%、14%、7%和7%的性能提升。受控实验与消融分析验证了轨迹级表征塑造与路径感知排序的互补作用。
原文摘要 · Abstract (English)
LeWM is a lightweight visual world model that learns latent dynamics end-to-end from pixels and ranks candidate action sequences by the distance between their predicted endpoints and the goal. However, LeWM has two limitations. First, during training, it learns local next-step transitions without evaluating complete trajectories relative to the task goal. Second, during planning, it ranks candidates solely by predicted endpoint distance. Because model predictions may differ from actual execution outcomes, the candidate whose predicted endpoint is closest to the goal may not perform best when executed in the environment. The evolution of the complete predicted trajectory can therefore provide complementary information beyond endpoint distance. To address these limitations, we propose Traj-LeWM, which retains LeWM's local-dynamics objective and endpoint score while introducing a goal-conditioned latent trajectory cost (LTC) that aggregates trajectory-level information as a complementary signal. During training, LTC-based trajectory-preference supervision complements next-step prediction in shaping the shared representation. During planning, LTC is combined with endpoint distance to incorporate intermediate-path information into candidate ranking. With joint endpoint-plus-LTC scoring, Traj-LeWM outperforms LeWM on Push-T, OGBench-Cube, Reacher, and Two-Room by $3$, $14$, $7$, and $7$ percentage points, respectively. Controlled experiments and ablations further verify the complementary roles of trajectory-level representation shaping and path-aware candidate ranking.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。