Dynamic Balance Control Algorithm of a Six-Legged Walking Robot, Little Crabster

This paper describes a center of pressure (CoP) control algorithm for maintaining dynamic balance of a six-legged walking robot, Little Crabster. Little Crabster is a ground walking test robot that has been manufactured as part of the process to develop an underwater six-legged walking robot named Crabster for underwater exploration and precise operations. Little Crabster is utilized to develop a walking algorithm with high walking stability in challenging environments. Although Little Crabster fundamentally has good walking stability with a large support polygon formed by its six legs, it is necessary to solve the body shaking problem, which lowers the visibility during walking, and enhance its waking stability under strong tidal currents and uneven terrains in underwater surroundings. Therefore, in this paper, sensory feedback controllers are designed to control the CoP, a criterion of dynamic balance, by modeling Little Crabster as an inverted pendulum model with a spring and a damper. In particular, a controller switching algorithm that leads to a smooth transition among the CoP controllers is proposed to cope with model parameter changes according to the variable number of supporting legs during walking. Finally, the performances of the CoP controllers and the controller switching algorithm are verified through several experiments using Little Crabster.

[1]  Nobuhiro Shimoi,et al.  Force/attitude control of mine detecting six-legged locomotion robot , 2000, Proceedings. 2000 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2000) (Cat. No.00CH37113).

[2]  Hanumant Singh,et al.  Issues in AUV design and deployment for oceanographic research , 1997, Proceedings of International Conference on Robotics and Automation.

[3]  Enric Celaya,et al.  Control of a six-legged robot walking on abrupt terrain , 1996, Proceedings of IEEE International Conference on Robotics and Automation.

[4]  Hidetoshi Takahashi,et al.  Development on Aquatic Walking Robot for Underwater Inspection , 1988 .

[5]  Kenzo Nonami,et al.  Robust Adaptive Fuzzy Control Law for Locomotion Control of a Hexapod Robot Actuated by Hydraulic Actuators with Dead Zone , 2006, 2006 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[6]  Rüdiger Dillmann,et al.  Pushing around a robot: Force-based manual control of the six-legged walking robot LAURON , 2011, 2011 IEEE International Conference on Robotics and Biomimetics.

[7]  H. Sakai,et al.  Design concept of a prototype amphibious walking robot for automated shore line survey work , 2004, Oceans '04 MTS/IEEE Techno-Ocean '04 (IEEE Cat. No.04CH37600).

[8]  Friedrich Pfeiffer,et al.  The six-legged TUM walking robot , 1994, Proceedings of IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS'94).

[9]  Bong-Huan Jun,et al.  A new concept and technologies of multi-legged underwater robot for high tidal current environment , 2011, 2011 IEEE Symposium on Underwater Technology and Workshop on Scientific Use of Submarine Cables and Related Technologies.

[10]  R. Wernli,et al.  ROV Technology Update From an International Perspective , 1984 .

[11]  O. Janrathitikarn,et al.  Gait Control of a Six-Legged Robot on Unlevel Terrain Using a Cognitive Architecture , 2008, 2008 IEEE Aerospace Conference.

[12]  Yosuke Kurihara,et al.  Motion control of multi-legged machines , 2009, 2009 ICCAS-SICE.

[13]  Bong-Huan Jun,et al.  Mechanical design of six-legged walking robot, Little Crabster , 2012, 2012 Oceans - Yeosu.

[14]  Taro Aoki,et al.  Development of deep sea free swimming ROV "UROV7K" , 1999, Oceans '99. MTS/IEEE. Riding the Crest into the 21st Century. Conference and Exhibition. Conference Proceedings (IEEE Cat. No.99CH37008).

[15]  V. S. Gurfinkel,et al.  The six-legged walking robot capable of terrain adaptation , 1983 .