Did you know there is an annual event in which robots play soccer? RoboCup  is a group of robot enthusiasts who come together to play soccer with their computers and electronic components rather than their feet. This last year the group met in June in Mexico City and next year they are on for the Netherlands.
It is surprisingly difficult to make a robot walk. These types of robots are called biped robots. Walking is something our brains do for us without any conscious thought but for a robot this task is much more difficult. Honda's ASIMO robot uses a Zero Moment Point algorithm. This means the robot is constantly adjusting for the force of gravity, the action of movement and the force of the floor pushing back against the robot's foot. We have our inner ear to help us adjust for movement and balance but in a robot this all must be programmed. At this time robots are only able to walk across smooth surfaces.
The hope for the future is that a robot can be invented that can walk over uneven surfaces, climb stairs and maybe even take out the trash and do our dishes.
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