We present a reactive controller that is able to displace a legged robot along an arbitrary trajectory with a high degree of accuracy. We designed the dieren t modules of our controller so that they can deal with arbitrary leg congurations. In this way, any leg movement necessary to overcome unexpected terrain irregularities can be correctly compensated by the controller, while still following the trajectory commanded by the user. Since we move the robot as a reaction to leg movements while stepping, the speed of the robot is automatically adjusted to the terrain prole: the more obstacles in the terrain, the more leg movements necessary to overcome them, and the slower the movement of the robot. We prove that, as the terrain becomes simpler, so does the gait generated by our controller, automatically converging to the tripod gait when the terrain becomes at. This is achieved without requiring a map of the terrain and, thus, our controller can be used by robots with minimum computational and sensing capabilities. The results we report using dieren t legged robots and in dieren t environments prove the adequacy of our approach.
['Josep M. Porta', 'Enric Celaya']
Reactive free-gait generation to follow arbitrary trajectories with a hexapod robot