Design of a social robot and safe social navigation with deep reinforcement learning

Abstract

This thesis is concerned with the design and development of a social robot that can navigate around in a socially compliant manner. The importance of this problem is due to the growing demand of using robots in human-populated environments. In this thesis, this problem is addressed in two concurrent parts. The first part has focused on the physical design and development of a social robot - named as SempRob. SempRob is aimed to have a sympathetic appearance while also having a design in which its visual sensors are located appropriately for environmental sensing. In the second part, the social navigation capability of the social robot is developed. First, a novel navigation method referred to as artificial potential function with reinforcement learning (APF-RL) method. In addition, an ellipse-based representation of obstacles is developed for efficient obstacle representation. Furthermore, environmental complexity measures are defined in order to ensure that learning scenarios incorporate a range of maneuvering difficulties. Both simulation and experimental results with SempRob demonstrate that APF-RL method enables the robot to move safely and efficiently in complex environments. Following, APF-RL method is extended to Social APF-RL method so that the robot additionally respects the comfort zones of the humans while navigating. This requires the robot to detect the humans in its surroundings and to track them spatially. A deep learning based human detection algorithm is combined with a Kalman filter for this purpose. Finally, Social APF-RL method is modified to be applicable in human following as well. All the proposed methods are tested on the developed robot successfully.