Control of hopping speed and height over unknown rough terrain using a single actuator

We present a method for controlling the forward speed and the apex height of a one-legged hopping robot over rough terrain, using a single actuator located at the robot hip. The control algorithm is comprised of two elements, the forward speed control and the height control. The only input to the system is the torque applied by the hip actuator. The control is demonstrated to perform tracking of desired forward speed trajectories and desired apex height trajectories. Simulation and experimental results on the SAHR (Single Actuator Hopping Robot) experimental setup are presented and compared. It is shown that the robot follows both trajectories closely in simulation as well as in experiment. Also the robot is tested successfully on a rough terrain course, which includes inclined ground and an abrupt drop in height of over 25% the length of the robot leg. The robot has no knowledge of its environment. Further, the robot is made to run over the course a number of times, to demonstrate the control robustness.

[1]  Robert B. McGhee,et al.  Adaptive Locomotion of a Multilegged Robot over Rough Terrain , 1979, IEEE Transactions on Systems, Man, and Cybernetics.

[2]  Evangelos Papadopoulos,et al.  Energy saving passive-dynamic gait for a one-legged hopping robot , 2006, Robotica.

[3]  Yasuhiro Fukuoka,et al.  Adaptive Dynamic Walking of a Quadruped Robot on Irregular Terrain Based on Biological Concepts , 2003, Int. J. Robotics Res..

[4]  Philip Holmes,et al.  Stability Analysis of a Clock-Driven Rigid-Body SLIP Model for RHex , 2004, Int. J. Robotics Res..

[5]  Takashi Emura,et al.  Energy-preserving control of a passive one-legged running robot , 2004, Adv. Robotics.

[6]  Luther R. Palmer,et al.  Quadrupedal running at high speed over uneven terrain , 2007, 2007 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[7]  Jessica K. Hodgins,et al.  Legged robots on rough terrain: experiments in adjusting step length , 1988, Proceedings. 1988 IEEE International Conference on Robotics and Automation.

[8]  Daniel E. Koditschek,et al.  RHex: A Simple and Highly Mobile Hexapod Robot , 2001, Int. J. Robotics Res..

[9]  Daniel E. Koditschek,et al.  Dynamic locomotion with four and six-legged robots , 2000 .

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