仿生工程学报 ›› 2017, Vol. 14 ›› Issue (2): 218-231.doi: 10.1016/S1672-6529(16)60393-1

• 论文 • 上一篇    下一篇

Virtual Constraint Based Control of Bounding Gait of Quadruped Robots

Qingyu Liu, Xuedong Chen, Bin Han, Zhiwei Luo, Xin Luo   

  1. State Key Laboratory of Digital Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
  • 收稿日期:2016-09-03 修回日期:2017-03-03 出版日期:2017-04-10 发布日期:2017-04-10
  • 通讯作者: Xin Luo E-mail:mexinluo@hust.edu.cn
  • 作者简介:Qingyu Liu, Xuedong Chen, Bin Han, Zhiwei Luo, Xin Luo

Virtual Constraint Based Control of Bounding Gait of Quadruped Robots

Qingyu Liu, Xuedong Chen, Bin Han, Zhiwei Luo, Xin Luo   

  1. State Key Laboratory of Digital Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
  • Received:2016-09-03 Revised:2017-03-03 Online:2017-04-10 Published:2017-04-10
  • Contact: Xin Luo E-mail:mexinluo@hust.edu.cn
  • About author:Qingyu Liu, Xuedong Chen, Bin Han, Zhiwei Luo, Xin Luo

摘要: This paper presents a control approach for bounding gait of quadruped robots by applying the concept of Virtual Constraints (VCs). A VC is a relative motion relation between two related joints imposed to the robots in terms of a specified gait, which can drive the robot to run with desired gait. To determine VCs for highly dynamic bounding gait, the limit cycle motions of the passive dynamic model of bounding gait are analyzed. The leg length and hip/shoulder angle trajectories corresponding to the limit cycles are parameterized by leg angles using 4 th-order polynomials. In order to track the calculated periodic motions, the polynomials are imposed on the robot as virtual motion constraints by a high-level state machine controller. A bounding speed feedback strategy is introduced to stabilize the robot running speed and enhance the stability. The control approach was applied to a newly designed lightweight bioinspired quadruped robot, AgiDog. The experimental results demonstrate that the robot can bound at a frequency up to 5 Hz and bound at a maximum speed of 1.2 m•s−1 in sagittal plane with a Froude number approximating to 1.

关键词: bounding gait, passive dynamics, bioinspired quadruped, virtual constraints

Abstract: This paper presents a control approach for bounding gait of quadruped robots by applying the concept of Virtual Constraints (VCs). A VC is a relative motion relation between two related joints imposed to the robots in terms of a specified gait, which can drive the robot to run with desired gait. To determine VCs for highly dynamic bounding gait, the limit cycle motions of the passive dynamic model of bounding gait are analyzed. The leg length and hip/shoulder angle trajectories corresponding to the limit cycles are parameterized by leg angles using 4 th-order polynomials. In order to track the calculated periodic motions, the polynomials are imposed on the robot as virtual motion constraints by a high-level state machine controller. A bounding speed feedback strategy is introduced to stabilize the robot running speed and enhance the stability. The control approach was applied to a newly designed lightweight bioinspired quadruped robot, AgiDog. The experimental results demonstrate that the robot can bound at a frequency up to 5 Hz and bound at a maximum speed of 1.2 m•s−1 in sagittal plane with a Froude number approximating to 1.

Key words: passive dynamics, bioinspired quadruped, bounding gait, virtual constraints