What is the Copenhagen Wheel’s control system all about? We continue to provide insights into the work done by our engineers and roboticists while working toward mass production of the Copenhagen Wheel.
JD - propulsion, motor control, batteries, the power system
As a part of my role at Superpedestrian, I ensure we have a battery that is well powered to drive the wheel with the right amount of assist desired. The battery needs to store ample energy to get the rider where they want to go, and repeat this a thousand times before wearing and needing replacement. We must use the energy we have available from the battery as efficiently as possible to drive torque to the Wheel as smoothly and precisely as possible.
The Wheel is controlled in a way that produces a magically satisfying ride. To achieve that we had to test candidate battery cells under cold, normal and hot conditions. We developed battery management electronics to ensure all cells will be treated properly and stay in balance. All the while, being kept away from voltage levels that could damage their health during discharge, charge, and regenerative braking. A precise field oriented controller keeps the applied motor currents properly positioned so that torque is efficiently produced as the motor position changes.
Julian - electrical engineer, research, testing, electrical and mechanical development
My current task is ensuring the embedded hardware supports the different features of the wheel. For example; field oriented control, temperature monitoring and GPS compatibility. I’ve been continuously reviewing schematics and debugging.
When I started here in February 2013, I was tasked with sourcing motors that could provide the performance we require. To test these motors, I developed a free-wheel dynamometer that evaluates their performance under different loads, current, voltage, and temperature conditions. I have explored different ways to control the prototype bikes with schemes I created and tested riding around Cambridge. The prototypes looked funny sometimes! :)
(Source: superpedestrian.com)
