Foot Placement Modification for a Biped Humanoid Robot with Narrow Feet

Kenji Hashimoto,Atsuo Takanishi,Kentaro Hattori,Hun-Ok Lim,Takuya Otani

doi:10.1155/2014/259570

Kenji Hashimoto, Atsuo Takanishi + Show 3 more

Open Access

https://doi.org/10.1155/2014/259570

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Journal: TheScientificWorldJournal	Publication Date: Jan 1, 2014
Citations: 20	License type: CC BY 3.0

Affiliation: Waseda University, Kanagawa University

Abstract

This paper describes a walking stabilization control for a biped humanoid robot with narrow feet. Most humanoid robots have larger feet than human beings to maintain their stability during walking. If robot's feet are as narrow as humans, it is difficult to realize a stable walk by using conventional stabilization controls. The proposed control modifies a foot placement according to the robot's attitude angle. If a robot tends to fall down, a foot angle is modified about the roll axis so that a swing foot contacts the ground horizontally. And a foot-landing point is also changed laterally to inhibit the robot from falling to the outside. To reduce a foot-landing impact, a virtual compliance control is applied to the vertical axis and the roll and pitch axes of the foot. Verification of the proposed method is conducted through experiments with a biped humanoid robot WABIAN-2R. WABIAN-2R realized a knee-bended walking with 30 mm breadth feet. Moreover, WABIAN-2R mounted on a human-like foot mechanism mimicking a human's foot arch structure realized a stable walking with the knee-stretched, heel-contact, and toe-off motion.

Highlights

We have developed a biped humanoid robot named WABIAN-2R (Waseda Bipedal Humanoid—No 2 Refined) as a human motion simulator to mimic human’s motions and mechanisms [1]
If a robot tends to fall down, a foot angle is modified about the roll axis so that a swing foot contacts the ground horizontally
To reduce a foot-landing impact, a virtual compliance control is applied to the vertical axis and the roll and pitch axes of the foot

Summary

Introduction

We have developed a biped humanoid robot named WABIAN-2R (Waseda Bipedal Humanoid—No 2 Refined) as a human motion simulator to mimic human’s motions and mechanisms [1] (see Figure 1). WABIAN-2R has achieved a human-like walk with the knee-stretched, heel-contact, and toe-off motion by utilizing a foot mechanism with a passive toe joint [2]. There are few biped robots which have realized a human-like walking with knee-stretched, heel-contact, and toe-off motion with narrow feet. We have developed a new biped foot mechanism mimicking a human’s foot arch structure as shown in Figure 2 [13], and the foot breadth is as narrow as 90 mm like humans. We aim to develop a walking stabilization control for a biped humanoid robot with narrow feet and realize a stable walking with the knee-stretched, heel-contact, and toe-off motion.

Foot Placement Modification

Experimental Tests and Consideration

Conclusions and Future Work