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arXiv 1609.05960cs.ROcs.AIcs.SYeess.SY
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基于增量采样的运动规划器使用策略迭代方法

Incremental Sampling-based Motion Planners Using Policy Iteration Methods

Jet Propulsion Laboratory(喷气推进实验室);Georgia Institute of Technology(佐治亚理工学院)

Oktay Arslan, Panagiotis Tsiotras

AI总结:

本文提出了一种基于策略迭代的运动规划算法,利用动态规划思想在随机图中求解最短路径问题,通过改进策略加速计算过程,适用于大规模并行化。

摘要:

最近随机运动规划的进步导致了一类新的基于采样的算法发展,这些算法提供了渐近最优性保证,例如RRT*和PRM*算法。仔细分析发现,这些算法中的所谓'重 wiring'步骤可以被解释为局部策略迭代(PI)步骤(即局部策略评估步骤后跟局部策略改进步骤),因此随着样本数趋于无穷大,这两种算法几乎肯定收敛到最优路径(概率1)。策略迭代,与价值迭代(VI)一样,是解决动态规划(DP)问题的常用方法。基于这一观察,最近提出了RRT#算法,该算法在每次迭代中对那些可能成为最优路径部分的顶点(即'有希望'的顶点)执行Bellman更新(即'备份')。RRT#算法因此利用了动态规划思想,并在随机生成的图上逐步实现以获得高质量的解决方案。在本文中,基于这一关键洞察,我们探索了一类不同的动态规划算法来解决由迭代采样方法生成的随机图中的最短路径问题。这些算法利用策略迭代而不是价值迭代,因此更适合大规模并行化。与RRT*算法不同,策略改进在重 wiring步骤中不是仅在局部进行,而是在当前迭代中被分类为'有希望'的顶点集合上进行。这倾向于加快整个过程。所得到的算法,恰当地命名为策略迭代-RRT#(PI-RRT#),是第一种基于动态规划思想的随机运动规划新类算法,利用PI方法。

英文摘要:

Recent progress in randomized motion planners has led to the development of a new class of sampling-based algorithms that provide asymptotic optimality guarantees, notably the RRT* and the PRM* algorithms. Careful analysis reveals that the so-called "rewiring" step in these algorithms can be interpreted as a local policy iteration (PI) step (i.e., a local policy evaluation step followed by a local policy improvement step) so that asymptotically, as the number of samples tend to infinity, both algorithms converge to the optimal path almost surely (with probability 1). Policy iteration, along with value iteration (VI) are common methods for solving dynamic programming (DP) problems. Based on this observation, recently, the RRT$^{\#}$ algorithm has been proposed, which performs, during each iteration, Bellman updates (aka "backups") on those vertices of the graph that have the potential of being part of the optimal path (i.e., the "promising" vertices). The RRT$^{\#}$ algorithm thus utilizes dynamic programming ideas and implements them incrementally on randomly generated graphs to obtain high quality solutions. In this work, and based on this key insight, we explore a different class of dynamic programming algorithms for solving shortest-path problems on random graphs generated by iterative sampling methods. These class of algorithms utilize policy iteration instead of value iteration, and thus are better suited for massive parallelization. Contrary to the RRT* algorithm, the policy improvement during the rewiring step is not performed only locally but rather on a set of vertices that are classified as "promising" during the current iteration. This tends to speed-up the whole process. The resulting algorithm, aptly named Policy Iteration-RRT$^{\#}$ (PI-RRT$^{\#}$) is the first of a new class of DP-inspired algorithms for randomized motion planning that utilize PI methods.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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