I. Introduction
The rise in popularity of humanoid robots will eventually lead to including them in all of our daily lives. Since these robots are opted to have the ability to move, act, and communicate like humans, eventually they will be used to replace humans in certain minimalist tasks or hazardous situations. Recent research shows and increased interest in such subject due to the recent availability of some commercial humanoid robot as evident by the increasing number of publications per year as shown in Fig. 1 . The presence of such commercial humanoid robots reduced the monopoly of robotics labs on robotics research and allowed more researcher to work on a multitude of topics that were difficult to achieve due to the lack of robots.