Pattern generation for bipedal walking on slopes and stairs

Uneven terrain walking is one of the key challenges in bipedal walking. In this paper, we propose a motion pattern generator for slope walking in 3D dynamics using preview control of zero moment point (ZMP). In this method, the future ZMP locations are selected with respect to known slope gradient. The trajectory of the center of mass (CoM) of the robot is generated by using the preview controller to maintain the ZMP at the desired location. Two models of slope walking, namely upslope and downslope, are investigated. Continuous walking on slopes with different gradients is also studied to enable the robots to walk on uneven terrains. Since staircase walking is similar to slope walking, the slope walking trajectory generator can also be applied to the staircase walking. Simulation results show that the robot can walk on many types of slopes and stairs by using the proposed pattern generator.

[1]  Chee-Meng Chew,et al.  Blind walking of a planar bipedal robot on sloped terrain , 1999, Proceedings 1999 IEEE International Conference on Robotics and Automation (Cat. No.99CH36288C).

[2]  Shuuji Kajita,et al.  Real-time 3D walking pattern generation for a biped robot with telescopic legs , 2001, Proceedings 2001 ICRA. IEEE International Conference on Robotics and Automation (Cat. No.01CH37164).

[3]  M Vukobratović,et al.  On the stability of biped locomotion. , 1970, IEEE transactions on bio-medical engineering.

[4]  Jonghoon Park,et al.  General ZMP Preview Control for Bipedal Walking , 2007, Proceedings 2007 IEEE International Conference on Robotics and Automation.

[5]  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).

[6]  Hiroshi Shimizu,et al.  Self-organized control of bipedal locomotion by neural oscillators in unpredictable environment , 1991, Biological Cybernetics.

[7]  Tatsuzo Ishida,et al.  Development of sensor system of a small biped entertainment robot , 2004, IEEE International Conference on Robotics and Automation, 2004. Proceedings. ICRA '04. 2004.

[8]  William D. Smart,et al.  Bipedal walking on rough terrain using manifold control , 2007, 2007 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[9]  Chee-Meng Chew,et al.  A uniform biped gait generator with offline optimization and online adjustable parameters , 2007, Robotica.

[10]  T. Katayama,et al.  Design of an optimal controller for a discrete-time system subject to previewable demand , 1985 .

[11]  Jessica K. Hodgins,et al.  Adjusting step length for rough terrain locomotion , 1991, IEEE Trans. Robotics Autom..

[12]  Masaki Ogino,et al.  Stabilizing biped walking on rough terrain based on the compliance control , 2007, 2007 IEEE/RSJ International Conference on Intelligent Robots and Systems.