Nick Carpenter
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FOC Motor Controller and Reaction-Wheel Inverted Pendulum

In Progress
  • Motor Control
  • Power Electronics
  • Embedded
  • Controls
  • PCB Layout
Type
Personal project, Jul 2026 to present
Role
Sole designer
Tools
STM32, Altium, LTspice, SolidWorks
Status
In progress. Brushless motor running under field-oriented control on a development kit; custom inverter PCB and control firmware in active development.
First motor spin under field-oriented control on the ST development kit
System block diagram: microcontroller, gate driver, three-phase inverter, motor, and feedback
System block diagram: microcontroller, gate driver, three-phase inverter, motor, and feedback
Initial concept sketch of the reaction-wheel inverted pendulum
Initial concept sketch of the reaction-wheel inverted pendulum
Early power stage schematic from the design phase
Early power stage schematic from the design phase

I am building my own field-oriented control (FOC) brushless motor controller for a reaction-wheel inverted pendulum. The robot will stay balanced by spinning a flywheel to create torque. My goal is to design and build every part myself, including the power electronics, PCB, control firmware, and mechanical parts.

I took on this project by myself to learn more about actuation and closed-loop control. I began by designing the system from the ground up, then focused on the hardware. I learned how a three-phase inverter with six MOSFETs works, what the gate driver does, and how the microcontroller, driver, and power stage all connect. Before designing my own board, I ran a brushless motor with field-oriented control on an STM32 development kit.

Next, I will move on to the main engineering steps. First, I plan to design my own 3-phase inverter PCB in Altium, using an STM32G4 microcontroller, a six-MOSFET power stage, a gate driver, and current sensors. After that, I will write the firmware for the control loop. Finally, I will design the mechanical reaction-wheel pendulum in SolidWorks and add encoder and IMU feedback to help the controller keep the robot balanced.

This is the project I am most excited about because I get to turn an idea into real hardware that can balance itself.