Toward Human Like Walking – Walking Mechanism of 3D Passive Dynamic Motion with Lateral Rolling – Advances in Human-Robot Interaction

Abstract

It may not be so science fiction any more that robots and human live in the same space. The robots may need to move like human and to have shape of humanoid in order to share the living space. Some robots may be required to walk along with human for special care. This requires robot to be able to walk like human and to sense how humans walk. Human walks by maximizing walking in between passive walking and active walking in effective manner such as less energy, less time, and so on (Ishiguro & Owaki, 2005). It is important to clarify the mechanisms of passive walking. This study is the first step to decrease the gap between robots and human in motion, advance in human-robot interaction. Most robots use actuators at each joint, and follow a certain selected trajectory in order to walk as mentioned active walking before. So, considerable power source is necessary to drive and control many actuators in joints. On the other hand, human swings a leg, leans its body forward, and uses potential energy in order to walk as if human tries to save energy to walk. Walking down the slope is one of the easiest conditions to walk (Osuka, 2002). The application of these human walking to the robots is called passive dynamic walking. A possibility to reproduce passive dynamic walking experimentally is introduced by McGeer (McGeer, 1990). Giving a simply structured walker proper initial conditions, the walker walks down the slope by inertial and gravitational force without any artificial energy externally. Goswami et al. carry out extensive simulation analysis, and show stability of walking and several other phenomena (Goswami et al., 1998; Goswami et al., 1998). In addition, Osuka et al. reproduce passive dynamic walking and the phenomena experimentally by using Quartet (walker)(Osuka et al., 1999; Osuka et al., 2000). However, the both studies constrain the yaw and rolling motion in order to simplify the analyses. Also, these analyses are made for legs without knees, so that extra care was necessary to make experimental analyses harder because the swing legs hit the slope at the position that it passes the supporting leg. In this study, the analyses were made three-dimensional walking with rolling motion. The 3D modeling, and simulation analysis were performed in order to search better walking