‘Friends’ – a Raspberry Pi-powered self‑balancing sculpture
By Ashley Whittaker. Posted
Dr Kevin Rathbone emailed us about a contemporary art project he’s created using Raspberry Pi. Called Friends, this trio of robots was part of an exhibition in Faugères, France called ‘Que Rien Ne Bouge’, which we are reliably told means ‘Let Nothing Move’.
“The artwork consists of three carbon-fibre frameworks that each balance on a single edge using the principle of an inverted pendulum with a reaction wheel,” explains Kevin. “To contrast the dynamic nature of the piece, the frameworks support rice-paper-bearing screen prints of Rodin’s Étude de robe de chambre pour Balzac, representing the material stability typically used in traditional stone or bronze sculptures.”
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The project was created with Antoine Espinasseau, a French artist based in Brussels. We’ve seen balancing robots before, but not balancing art.
“A Raspberry Pi 3B at the heart of the system runs a C program, interfacing with a custom add-on board,” Kevin says. “The board integrates an IMU, current sensing, a piezo sounder, and a CAN HAT to communicate with a servo drive. The control loop runs at 200Hz, continuously adjusting the balance by reading gyro and accelerometer data (which is run through a complementary filter), estimating the tilt angle (which may change due to a breeze), running a PI (Proportional-Integral) controller, and feeding velocity commands to a servo drive that powers a brushless motor connected to a harmonic drive – a gearbox with zero backlash.”
You can see a video of the pieces in action below.
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