Optimum Biped Trajectory Planning for Humanoid Robot Navigation in Unseen Environment 175 Optimum Biped Trajectory Planning for Humanoid Robot Navigation in Unseen Environment

The study on biped locomotion in humanoid robots has gained great interest since the last decades (Hirai et. al. 1998, Hirukawa et. al., 2004, Ishiguro, 2007). This interest are motivated from the high level of mobility, and the high number of degrees of freedom allow this kind of mobile robot adapt and move upon very unstructured sloped terrain. Eventually, it is more desirable to have robots of human build instead of modifying environment for robots (Khatib et. al, 1999). Therefore, a suitable navigation system is necessary to guide the robot’s locomotion during real-time operation. In fundamental robot navigation studies, robot system is normally provided with a map or a specific geometrical guidance to complete its tasks (Okada et al., 2003, Liu et al., 2002). However during operation in uncertain environment such as in emergency sites like an earthquake site, or even in a room that the robots never been there before, which is eventually become the first experience for them, robots needs some intelligence to recognize and estimate the position and structure of objects around them. The most important is robot must localize its position within this environment and decide suitable action based on the environment conditions. To archives its target tasks, the robot required a highly reliable sensory devices for vision, scanning, and touching to recognize surrounding. These problems have become the main concern in our research that deals with humanoid robot for application in built-for-human environment. Operation in unseen environment or areas where visual information is very limited is a new challenge in robot navigation. So far there was no much achievement to solve robot navigation in such environments. In previous research, we have proposed a contact interaction-based navigation strategy in a biped humanoid robot to operate in unseen environment (Hanafiah et al., 2008). In this chapter, we present analysis results of optimum biped trajectory planning for humanoid robot navigation to minimize possibility of collision during operation in unseen environment. In this analysis, we utilized 21-dof biped humanoid robot Bonten-Maru II. Our aim is to develop reliable walking locomotion in order 9