A new humanoid robot-WABIAN-2- that can be used as a human motion simulator is proposed in this paper. Its trunk is designed in order to permit rotation, and forward, backward, and sideway movement. Further, its arms are designed to support its complete weight when pushing a walk-assist machine. Moreover, it can lean on a walk-assist machine by forearm control using trunk motion. Basic walking experiments with WABIAN-2 are conducted with and without a walk-assist machine, thereby confirming its effectiveness

A humanoid robot, WABIAN-2R, capable of human-like walk with stretched knees and heel-contact and toe-off motions is proposed in this paper. WABIAN-2R has two 1-DOF passive joints in its feet to enable it to bend its toes in steady walking. Further, it has two 6-DOF legs, a 2-DOF pelvis, a 2-DOF trunk, two 7-DOF arms with 3-DOF hands, and a 3-DOF neck. In addition, a new algorithm for generating walking patterns with stretched knees and heel-contact and toe-off motions based on the ZMP criterion is described. In this pattern generation, some parameters of the foot trajectories of a biped robot are optimized by using a genetic algorithm in order to generate a continuous and smooth leg motion. Software simulations and walking experiments are conducted, and the effectiveness of the pattern generation and mechanism of WABIAN-2R, which have the ability to realize more human-like walking styles in a humanoid robot, are confirmed