With the emergence of more and more torquecontrolled
robots, the agility of leg locomotion has been promoted
to a new level, which, however, seems also to imply that only
torque-controlled robots are appropriate for leg locomotion. This
paper demonstrates that a position-control-based robot could also
achieve dynamically stable and robust locomotion. With the help
of offline dynamic-model-based trajectory optimization
algorithms and online simplified-model-based reactive controller,
the tested quadruped robot Pupper achieved dynamically stable
trot gait both on flat grounds and high slopes of at most 20 degrees.
It also gained the ability to trot on and off a 10 mm plank blindly,
proving the control framework’s effectiveness as well as the
potential of a position-control-based robot for indoor or structural
environments.