Bipedal robots often have to take a series of small steps in order to turn around, which usually takes up valuable time. Some robots are capable of twisting their legs outwards 90 degrees at the hip in order to turn in fewer steps, but that runs the risk of unbalancing the robot. And both of these methods require a lot of space, which a robot may not have if facing a wall or counter. Researchers at Ritsumeikan University and the Osaka Electro-Communications University are proposing that a stable, fully grounded shuffle is a safer and more efficient way to turn.
They’re using a modified Fujitsu HOAP-2 in their experiments, and have shown the robot is able to turn 30 degrees by controlling the load distribution on the soles of the feet. The robot can also maintain ground contact when turning by sliding its feet, if the floor is smooth enough. Granted, it won’t work in every circumstance (floors with greater friction prevents shuffling), but it could be useful. Their research on this topic goes back to 2009.
Video (Simultaneous Parallel Shuffle Translation on Low Friction Floor):
Waseda University researchers are presenting something similar with the full-sized WABIAN-2R. The robot is able to turn 90 degrees in about 2 seconds by slipping on one foot while remaining stable with the other.
They’ve also shown that by adding just 10mm of soft material to the feet dramatically improves a robot’s balance when walking on uneven terrain. After the break, you can watch the HOAP-2 walking on a plank with studs, both with and without soft soles, and see the difference it makes.
Video (conventional turning):
Video (walking on uneven terrain without soft soles):
Video (walking on uneven terrain with soft soles):
[source: MasaKoeda @ YouTube]