Including Joint Torques and Power Consumption in the Stability Margin of Walking Robots

Walking robots possess important inherent advantages as autonomous systems, and many techniques have been developed during the last three decades to improve these mobile systems significantly. However, when robots attempt to walk through realistic scenarios, some techniques exhibit important shortcomings. One such shortcoming is to define the robot's quasi-static-stability margin using only the geometric parameters of the robot, neglecting the influence of real systems' motor-torque and power-consumption limitations. This paper reviews quasi-static stability theory for walking robots, illustrates real problems through simulation and experiments using real walking machines, and proposes a new concept of quasi-static stability that takes into consideration some of the robot's intrinsic parameters. The resulting stability measurement can improve efficiency in terms of robot design and power consumption, two aspects that are of paramount importance in autonomous walking robots for real applications.