Field-oriented Control (FOC), that is, Field Oriented Control, also known as vector frequency conversion, is currently the best choice for efficient control of brushless direct current motor (BLDC) and permanent magnet synchronous motor (PMSM).
    FOC precisely controls the size and direction of the magnetic field, making the motor torque stable, low noise, high efficiency, and has a high-speed dynamic response. At present, it has gradually replaced the traditional control method in many applications, and has attracted much attention in the motion control industry.

    FOC control first needs to obtain the motor rotor position, motor speed, current size and other information as feedback input, need to collect the motor phase current, and carry out a series of mathematical transformation and estimation algorithm to obtain the decoupled easy-to-control feedback quantity.
    The controller adjusts dynamically according to the error between the feedback quantity and the target value, and finally outputs 3-phase sine wave to drive the motor to rotate.