balavignesh2125
Cubli
Overview
The Cubli is a 3-axis reaction wheel based balancing cube designed to balance on an edge and a corner. This project combines embedded C++, inertial sensing, feedback control, and motor actuation to demonstrate active attitude stabilisation on a physical system.
The accompanying video shows the Cubli balancing on an edge.
Demonstration
The demonstration video is available on the portfolio homepage.
System Architecture
- Microcontroller: Teensy 4.1
- Inertial measurement unit: BMI270
- Motor control: Moteus motor drive
- Communication: CAN bus, SPI, I2C
- Software: Embedded C++ using the Arduino framework and PlatformIO
The hardware configuration of the successful demonstration must be confirmed against the original working version.
Control and State Estimation
- Attitude estimation: IMU measurement processing and complementary filtering
- Feedback control: Linear Quadratic Regulator (LQR) implementation
- Motor actuation: Torque commands sent to the motor drive
- Embedded execution: Sensor acquisition, state processing, and control-loop execution
The exact relationship between these components in the successful three-axis balancing implementation remains to be verified.
Mathematical Model
- Body attitude and angular velocity
- Reaction wheel angular velocities
- Coupling between axes
- State space representation is used by the controller
- Coordinate frame transofmration
The equations, parameters, and state definitions will be added after the working implementation is recovered or verified.
Experimental Results
- Repeatable edge balance( up to 5 minutes), corner balance (a few seconds)
- Attitude stability and settling behaviour irrespective of surfaces, sharp edges and corners
- Reaction wheel speed and control effort
- Sensor noise and estimation performance
- Stabilising behaviour under small disturbances