A Markov chain Monte Carlo algorithm for Bayesian policy search

Autor: Vahid Tavakol Aghaei, Ahmet Onat, Sinan Yıldırım
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Systems Science & Control Engineering, Vol 6, Iss 1, Pp 438-455 (2018)
Druh dokumentu: article
ISSN: 2164-2583
21642583
DOI: 10.1080/21642583.2018.1528483
Popis: Policy search algorithms have facilitated application of Reinforcement Learning (RL) to dynamic systems, such as control of robots. Many policy search algorithms are based on the policy gradient, and thus may suffer from slow convergence or local optima complications. In this paper, we take a Bayesian approach to policy search under RL paradigm, for the problem of controlling a discrete time Markov decision process with continuous state and action spaces and with a multiplicative reward structure. For this purpose, we assume a prior over policy parameters and aim for the ‘posterior’ distribution where the ‘likelihood’ is the expected reward. We propound a Markov chain Monte Carlo algorithm as a method of generating samples for policy parameters from this posterior. The proposed algorithm is compared with certain well-known policy gradient-based RL methods and exhibits more appropriate performance in terms of time response and convergence rate, when applied to a nonlinear model of a Cart-Pole benchmark.
Databáze: Directory of Open Access Journals