用接触信号解决物体位置不确定时的抓取难题,实现实时高效规划。
A POMDP-based hierarchical planning framework for manipulation under pose uncertainty
- 分层信念表示:先粗略定位再精细优化,降低计算负担
- 真实场景下成功率达93%,比贪心基线提升50%以上
- 适合复杂家居环境中的机器人抓取任务,支持实时执行
机器人在家庭环境中常面临视觉反馈失效的问题,如物体被遮挡或黑暗中寻找开关。此时,利用接触信号进行目标定位更为有效。本文提出一种基于部分可观测马尔可夫决策过程(POMDP)的在线规划框架,使用二值接触信号处理姿态不确定性。传统粒子集表示信念在家庭环境的大不确定性下导致计算不可行,需滚动数万次动作、百万级粒子,耗时过长。为此,我们设计分层信念表示:初始在三维体素空间粗粒度建模不确定性,计算并执行能缩小不确定性的策略;当不确定性足够降低后,转换回粒子空间进一步细化,直至任务完成。采用基于启发式搜索的任意时间求解器,在有限时间预算内生成部分策略,实现闭环规划与执行。该框架在真实世界和仿真中均验证了有效性,使用UR10e机械臂完成插头插入插座的高精度任务,可处理最大50厘米的位置不确定性及接近2π的角不确定性。实验表明,真实环境下成功率高达93%,解决方案质量相比贪心基线提升超过50%,显著加速规划,支持复杂问题的实时求解。
原文摘要 · Abstract (English)
Robots often face challenges in domestic environments where visual feedback is ineffective, such as retrieving objects obstructed by occlusions or finding a light switch in the dark. In these cases, utilizing contacts to localize the target object can be effective. We propose an online planning framework using binary contact signals for manipulation tasks with pose uncertainty, formulated as a Partially Observable Markov Decision Process (POMDP). Naively representing the belief as a particle set makes planning infeasible due to the large uncertainties in domestic settings, as identifying the best sequence of actions requires rolling out thousands of actions across millions of particles, taking significant compute time. To address this, we propose a hierarchical belief representation. Initially, we represent the uncertainty coarsely in a 3D volumetric space. Policies that refine uncertainty in this space are computed and executed, and once uncertainty is sufficiently reduced, the problem is translated back into the particle space for further refinement before task completion. We utilize a closed-loop planning and execution framework with a heuristic-search-based anytime solver that computes partial policies within a limited time budget. The performance of the framework is demonstrated both in real world and in simulation on the high-precision task of inserting a plug into a port using a UR10e manipulator, resolving positional uncertainties up to 50 centimeters and angular uncertainties close to $2π$. Experimental results highlight the framework's effectiveness, achieving a 93\% success rate in the real world and over 50\% improvement in solution quality compared to greedy baselines, significantly accelerating planning and enabling real-time solutions for complex problems.
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。