Online path planning of cooperative mobile robots in unknown environments using improved Q-Learning and adaptive artificial potential field

Online path planning in unknown environments with obstacles is a challenging issue in mobile robot systems. Cooperative mobile robots have received much attention in recent years due to their robustness and ability to perform more complex tasks and operations faster. In this article, by unifying the Dyna Q-learning and a novel concept (introduced as a feature matrix) an improved Q-learning is proposed that accelerates the learning process even with poor choice of parameters. In addition, to overcoming the local minima, an adaptive artificial potential field method is developed, so that two parameters of the new concept named the virtual obstacle are controlled using the massachusetts institute of technology (MIT) method to navigate the mobile robot in the proper direction. Then, with proper utilizing of the improved Q-learning and adaptive artificial potential field method, the path planning is performed online effectively while target tracking and collision avoidance are guaranteed. Finally, the performance of the proposed method is tested on decentralized cooperative mobile robots. The simulation results showed optimal path planning in terms of the distance in an unknown environment and collision avoidance with the obstacles. In addition, getting out of the local minima (i.e. immobility) is guaranteed in all situations.