Title: Bipedal Walking with Corrective Actions in the Tilt Phase Space,
Abstract: Many methods exist for a bipedal robot to keep its balance while walking. In
addition to step size and timing, other strategies are possible that influence
the stability of the robot without interfering with the target direction and
speed of locomotion. This paper introduces a multifaceted feedback controller
that uses numerous different feedback mechanisms, collectively termed
corrective actions, to stabilise a core keypoint-based gait. The feedback
controller is experimentally effective, yet free of any physical model of the
robot, very computationally inexpensive, and requires only a single 6-axis IMU
sensor. Due to these low requirements, the approach is deemed to be highly
portable between robots, and was specifically also designed to target lower
cost robots that have suboptimal sensing, actuation and computational
resources. The IMU data is used to estimate the yaw-independent tilt
orientation of the robot, expressed in the so-called tilt phase space, and is
the source of all feedback provided by the controller. Experimental validation
is performed in simulation as well as on real robot hardware.