Water cooled servo

I came over this really innovative solution to a common problem in robotics, namely the lack of power.

The hopelessly American solution as employed by robotics specialist Boston Dynamics as can seen in footage of their legendary big dog robot among others is simply to put a big noisy petroleum engine into the robot capable of driving the hydraulics system with the power they need to make it jump around like a gazelle on steroids.

Now another approach has surfaced that has more intelligence and lateral thinking to it. SCHAFT is a relatively small Japanese robotics company recently purchased by Google. They compete in the DARPA robot challenge, and have won at least one competition.

According to them the reason for their win is simply that they have managed to create "much stronger muscles" in their robots (higher power to weight ratio in servo motors). Their idea boils down to a brilliantly simple concept: Pump too much current into the motors but keep the motor from burning up by applying enough cooling.

SCHAFT robot motor and controller

So how do they provide more power? They solved this simply by raising the voltage of the power source beyond what a normal motor would endure and putting a capacitor bank between the power source_(battery) and the motors capable of delivering enough current even for the "spikes".

And how is cooling solved? They have constructed sealed motors that allows them to circulate non-conductive liquid coolant through the motors. The heated liquid pass through a passive heat exchanger that effectively dissipates the excess heat to the air around the robot.

I will definite look at ways of using this concept once I get the chance!

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