A self-balancing electric monowheel — an exploration of the mechanical and control boundaries of single-wheel personal mobility.
Design and build a functional self-balancing monowheel — integrating drive motor, battery, IMU, and control electronics within a single-wheel chassis while maintaining a rideable center of gravity and responsive balance control.
Full mechanical design of the chassis and wheel assembly, motor and battery integration, electronics packaging, and control system architecture. Full prototype build and tuning.
Functional self-balancing monowheel prototype capable of controlled forward and reverse travel. Developed as an internal R&D project demonstrating advanced mechatronic integration.
Austin was born as an internal challenge: could we design and build a genuinely functional self-balancing monowheel — one of the most mechanically demanding personal mobility concepts — within a constrained development timeline? The answer turned out to be yes, but it required solving several problems that don't exist in conventional electric vehicle design.
The fundamental challenge of a monowheel is that the rider sits inside the wheel. This means the drive system, battery, and electronics all need to be packaged within the rotating rim envelope, or mounted on the inner chassis in a way that keeps the center of gravity low enough to be manageable. Our approach placed the motor and drive electronics within the hub, with the battery pack on the inner chassis at the lowest possible position.
The balance control system uses an IMU to measure pitch angle and rate, feeding a PID-based torque controller that drives the motor to maintain balance. Tuning this controller required careful attention to the mechanical dynamics — moment of inertia, tire contact dynamics, and the lag between control input and mechanical response all affect stability. We iterated through multiple control parameter sets before finding a tuning that felt natural to ride.
The chassis design had to satisfy conflicting requirements: stiff enough to handle the dynamic loads of riding, light enough not to raise the center of gravity too high, and compact enough to fit inside the wheel rim with adequate clearance. We used FEA to optimize the chassis geometry and selected aluminium alloy for the primary structure with a carbon fibre reinforced polymer (CFRP) cover for the housing panels.
Austin demonstrated that our team can handle the full stack from mechanical architecture through control system design — a capability that transfers directly to client projects in mobility, robotics, and advanced mechatronic systems.