This Nifty Robot Arm Can Balance an Inverted Pendulum Pneumatically

When you need a robot to move, the easiest way to make that happen is with electric motors. They’re relatively cheap, readily available, and easy to control. But, that doesn’t mean they’re the best solution. Hydraulics, for example, are better for heavy lifting. Pneumatics are another option, and this soft robot arm proves that they can be used for dexterous tasks like balancing an inverted pendulum.

Soft robotics is still a field in its infancy, and even performing a relatively simple task like balancing a Furuta inverted pendulum can be difficult. This robot does that with just one degree of freedom that allows the arm to pivot in the horizontal plane. That would be straightforward — almost trivial — to do with an electric motor, but a lot harder to achieve with a soft robotic mechanism. That’s because soft robots generally work by pumping air or fluid into pockets, which can be tricky to control with any kind of precision.

This robot accomplishes that with two inflatable air bladders positioned on either side of the pivot point. When air is pumped in through switching valves, the pressure causes either the left or right bladder to expand. The bladder fans out like an accordion and rotates the arm. When that movement is precisely coordinated, the robot is able to keep the inverted pendulum balanced. While this robot was built as a proof of concept, it demonstrates the viability of pneumatic soft robots for industrial use.