Publication
Practical resolution methods for MDPs in robotics exemplified with disassembly planning
Journal Article (2019)
Journal
IEEE Robotics and Automation Letters
Pages
2282-2288
Volume
4
Number
3
Doc link
https://doi.org/10.1109/LRA.2019.2901905
File
Abstract
In this paper we focus on finding practical resolution methods for Markov Decision Processes (MDPs) in robotics. Some of the main difficulties of applying MDPs to real-world robotics problems are: (1) having to deal with huge state spaces; and (2) designing a method that is robust enough to dead ends. These complications restrict or make more difficult the application of methods such as Value Iteration, Policy Iteration or Labeled Real Time Dynamic Programming (LRTDP). We see in determinization and heuristic search a way to successfully work around these problems. In addition, we believe that many practical use cases offer the opportunity to identify hierarchies of subtasks and solve smaller, simplified problems. We propose a decision-making unit that operates in a probabilistic planning setting through Stochastic Shortest Path Problems (SSPPs), which generalize the most common types of MDPs. Our decision-making unit combines: (1) automatic hierarchical organization of subtasks; and (2) on-line resolution via determinization. We argue that several applications of planning benefit from these two strategies. We exemplify our approach with a robotized disassembly application. The disassembly problem is modeled in Probabilistic Planning Definition Language (PPDDL), and serves to define our experiments. Our results show many advantages of our method over LRTDP, like a better capability to handle problems with large state spaces and state definitions that change when new fluents are discovered.
Categories
learning (artificial intelligence), planning (artificial intelligence), robots, uncertainty handling.
Scientific reference
A. Suárez, C. Torras and G. Alenyà. Practical resolution methods for MDPs in robotics exemplified with disassembly planning. IEEE Robotics and Automation Letters, 4(3): 2282-2288, 2019.
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