Robust Bipedal Locomotion Based on a Hierarchical Control Structure

Luo, Jianwen1,2; Su, Yao3; Ruan, Lecheng3; Zhao, Ye4; Kim, Donghyun5; Sentis, Luis6; Fu, Chenglong1

2019-10

10.1017/S0263574719000237

ROBOTICA   影响因子和分区

0263-5747

1469-8668

To improve biped locomotion's robustness to internal and external disturbances, this study proposes a hierarchical structure with three control levels. At the high level, a foothold sequence is generated so that the Center of Mass (CoM) trajectory tracks a planned path. The planning procedure is simplified by selecting the midpoint between two consecutive Center of Pressure (CoP) points as the feature point. At the middle level, a novel robust hybrid controller is devised to drive perturbed system states back to the nominal trajectory within finite cycles without chattering. The novelty lies in that the hybrid controller is not subject to linear CoM dynamic constraints. The hybrid controller consists of two sub-controllers: an oscillation controller and a smoothing controller. For the oscillation controller, the desired CoM height is specified as a sine-shaped function, avoiding a new attractive limit cycle. However, this controller results in the inevitable chattering because of discontinuities. A smoothing controller provides continuous properties and thus can inhibit the chattering problem, but has a smaller region of attraction compared with the oscillation controller. A hybrid controller merges the two controllers for a smooth transition. At the low level, the desired CoM motion is defined as tasks and embedded in a whole body operational space (WBOS) controller to compute the joint torques analytically. The novelty of the low-level controller lies in that within the WBOS framework, CoM motion is not subject to fixed CoM dynamics and thus can be generalized.

Robust locomotion Generic point mass model Whole body control Operational space

SCI ; EI

英语

第一 ; 通讯

NSF[1724360]

Robotics

Robotics

WOS:000484966400006

CAMBRIDGE UNIV PRESS

20191006601527

Flight dynamics

Control Equipment:732.1

ENGINEERING

Web of Science

1.Southern Univ Sci & Technol, Dept Mech & Energy Engn, Shenzhen, Peoples R China
2.Stanford Univ, Dept Comp Sci, Stanford, CA 94305 USA
3.Univ Calif Los Angeles, Dept Mech & Aerosp Engn, Los Angeles, CA USA
4.Georgia Inst Technol, Woodruff Sch Mech Engn, Atlanta, GA 30332 USA
5.MIT, Dept Mech Engn, Cambridge, MA 02139 USA
6.Univ Texas Austin, Dept Aerosp Engn & Engn Mech, Austin, TX 78712 USA

Luo, Jianwen,Su, Yao,Ruan, Lecheng,et al. Robust Bipedal Locomotion Based on a Hierarchical Control Structure[J]. ROBOTICA,2019,37(10):1750-1767.

Luo, Jianwen.,Su, Yao.,Ruan, Lecheng.,Zhao, Ye.,Kim, Donghyun.,...&Fu, Chenglong.(2019).Robust Bipedal Locomotion Based on a Hierarchical Control Structure.ROBOTICA,37(10),1750-1767.

Luo, Jianwen,et al."Robust Bipedal Locomotion Based on a Hierarchical Control Structure".ROBOTICA 37.10(2019):1750-1767.