CausalWAM:在世界动作模型中学习动作的成因
CausalWAM: Learning the Causes of Actions in World Action Models
Juntao Cheng · Jinzhou Tang · Fan Feng · Henrik I. Christensen · Yujia Zheng
中文摘要
世界动作模型(WAM)从观测中学习潜变量,并用这些潜变量预测场景演化与生成动作。预测需覆盖整个场景,但只有部分场景是动作的成因。基于示范数据拟合的 WAM 通常无法保证仅由被示范动作的潜在成因(动作相关潜变量)生成动作,因为模型也可能以这种方式学习模仿,同时将动作相关潜变量与干扰变量纠缠在一起。因此,将“什么导致动作”与“预测依赖什么”分离。证明在稀疏性约束下,用于生成动作的潜变量仅是动作相关潜变量的可逆函数,且真实结构在潜变量置换意义下可识别。这既不需要充分的时间依赖性,也不需要对未观测状态如何演化作任何假设,并且在动作相关潜变量与其余变量统计相关时依然成立。据此提出 CWAM(Causal WAM),通过在其动作头上增加稀疏路由路径,将约束融入预训练 WAM,而世界建模目标保持不变。合成数据与真实机器人实验验证了理论,并展示了闭环成功率的效率提升。
关键要点
- 01WAM 从观测学潜变量预测场景并生成动作,但预测需覆盖全场景,仅部分场景是动作成因。
- 02示范拟合的 WAM 可能将动作相关潜变量与干扰变量纠缠,无法保证仅由潜在成因生成动作。
- 03证明稀疏性约束下动作生成潜变量是动作相关潜变量的可逆函数,结构可识别至置换。
- 04CWAM 在预训练 WAM 动作头加稀疏路由路径,世界建模目标不变。
- 05合成数据与真实机器人实验验证理论,并展示闭环成功率效率提升。
解读
尚无解读。
原始英文摘要
arXiv:2610.42096v1 Announce Type: cross Abstract: World action models (WAMs) learn latent variables from observations and use these to both predict the evolution of the scene and to generate actions. The prediction has to be of the whole scene, whereas only a portion of the scene causes actions. WAMs fitted to demonstrations do not, in general, guarantee that they will generate actions solely from the latent causes of the demonstrated actions (the action-relevant latent variables), as the model could just as well learn to imitate in this way whilst entangling the action-relevant latent variables with the nuisance variables. We therefore separate out what causes action from what prediction depends on. We prove that under a sparsity constraint the latent variables used to generate actions are an invertible function of the action-relevant latent variables alone and the true structure is identified up to a permutation of the latent variables. This requires neither sufficient temporal dependence nor any assumptions on how the unobserved regimes evolve and holds even when the action-relevant latent variables are statistically dependent on the rest. We therefore propose CWAM (Causal WAM), which incorporates the constraint into a pretrained WAM by adding a sparse routing path to its action head, with the world modeling objective remaining unchanged. Experiments on both synthetic data and real-world robots validate the theory as well as showcase the improved efficiency in closed-loop success.