From one-legged hopping to bipedal running and walking: A unified foot placement control based on regression analysis

This paper aims at developing a unified and adaptive foot placement control for legged robots. The locomotion control of legged robots can be classified into three parts as body height control, body attitude control, and forward velocity control. In our study, the body attitude is controlled at stance phase by the hip actuator, and the height is controlled by the motion of the stance leg. In this case, the foot placement has a nearly linear correlation with forward velocity. Hereby, a generic foot placement controller is developed to control the forward velocity based on the online linear regression analysis of their coupled correlation. Our proposed algorithm is capable of adjusting the control parameters automatically, and is featured by good adaptability and higher control accuracy that outperforms the empirical tuning. The very same controller is able to produce stable hopping with accurate forward velocity tracking even with unknown mass offset, as well as stable bipedal running and walking with accurate velocity tracking.

[1]  Tad McGeer,et al.  Passive Dynamic Walking , 1990, Int. J. Robotics Res..

[2]  R. Siegwart,et al.  ScarlETH: Design and Control of a Planar Running Robot , 2011 .

[3]  Reinhard Blickhan,et al.  Compliant leg behaviour explains basic dynamics of walking and running , 2006, Proceedings of the Royal Society B: Biological Sciences.

[4]  Martin Buehler,et al.  Stable control of a simulated one-legged running robot with hip and leg compliance , 1997, IEEE Trans. Robotics Autom..

[5]  Christopher G. Atkeson,et al.  Versatile and robust 3D walking with a simulated humanoid robot (Atlas): A model predictive control approach , 2014, 2014 IEEE International Conference on Robotics and Automation (ICRA).

[6]  Darwin G. Caldwell,et al.  Virtual model control for quadrupedal trunk stabilization , 2013 .

[7]  Marc H. Raibert,et al.  Legged Robots That Balance , 1986, IEEE Expert.

[8]  Marc H. Raibert,et al.  Tabular control of balance in a dynamic legged system , 1984, IEEE Transactions on Systems, Man, and Cybernetics.

[9]  Nikolaos G. Tsagarakis,et al.  Walking pattern generation for a humanoid robot with compliant joints , 2013, Auton. Robots.

[10]  Russell L. Tedrake,et al.  Applied optimal control for dynamically stable legged locomotion , 2004 .

[11]  Henk Nijmeijer,et al.  Foot placement for planar bipeds with point feet , 2012, 2012 IEEE International Conference on Robotics and Automation.

[12]  Eric Kubica,et al.  Introduction of the Foot Placement Estimator: A Dynamic Measure of Balance for Bipedal Robotics , 2008 .

[13]  Kazuhito Yokoi,et al.  Biped walking pattern generation by using preview control of zero-moment point , 2003, 2003 IEEE International Conference on Robotics and Automation (Cat. No.03CH37422).

[14]  Nikolaos G. Tsagarakis,et al.  Fast bipedal walk using large strides by modulating hip posture and toe-heel motion , 2010, 2010 IEEE International Conference on Robotics and Biomimetics.

[15]  Nikolaos G. Tsagarakis,et al.  Walking trajectory generation for humanoid robots with compliant joints: Experimentation with COMAN humanoid , 2012, 2012 IEEE International Conference on Robotics and Automation.

[16]  Jerry E. Pratt,et al.  Intuitive control of a planar bipedal walking robot , 1998, Proceedings. 1998 IEEE International Conference on Robotics and Automation (Cat. No.98CH36146).

[17]  Kevin Blankespoor,et al.  BigDog, the Rough-Terrain Quadruped Robot , 2008 .

[18]  David E. Orin,et al.  Intelligent control of quadruped gallops , 2003 .