Motor controller, image forming apparatus and motor controlling method

A motor controller for controlling a motor according to a control cycle, the motor including a coil that generates a rotating magnetic field and a rotor that is formed using a permanent magnet and rotates by the rotating magnetic field generated by the coil, the motor controller comprising:

• a processor;
• and
• a voltage controller,
• the processor obtaining a rotation position and an angular velocity of the rotor at a first time point,
• based on an angular acceleration of the rotor, the angular velocity of the rotor at the first time point and a time length of the control cycle, the processor calculating a compensation angle by which the rotor advances from the first time point to a second control cycle subsequent to a first control cycle including the first time point,
• the voltage controller controlling a voltage to be applied to the coil such that a rotating magnetic field based on a rotation position of the rotor advanced by the compensation angle from the rotation position of the rotor at the first time point is formed in the second control cycle,
• wherein
• the voltage controller controls the voltage to be applied to the coil according to PWM control,
• the control cycle is a PWM cycle, and
• the processor calculates, as the compensation angle, an angle by which the rotor advances in a control delay time period from the first time point to a second time point in a middle of a pulse output time period in the second control cycle, and wherein
• the processor sets a target angular acceleration of the rotor,
• the voltage controller controls the voltage to be applied to the coil such that the angular acceleration of the rotor becomes closer to the target angular acceleration, and
• the processor calculates the compensation angle based on a change in the target angular acceleration set for the control delay time period.

A motor controller for controlling a motor according to a control cycle, the motor including a coil that generates a rotating magnetic field and a rotor that is formed using a permanent magnet and rotates by the rotating magnetic field generated by the coil, the motor controller comprising:

• a processor;
• and
• a voltage controller,
• the processor obtaining a rotation position and an angular velocity of the rotor at a first time point,
• based on an angular acceleration of the rotor, the angular velocity of the rotor at the first time point and a time length of the control cycle, the processor calculating a compensation angle by which the rotor advances from the first time point to a second control cycle subsequent to a first control cycle including the first time point,
• the voltage controller controlling a voltage to be applied to the coil such that a rotating magnetic field based on a rotation position of the rotor advanced by the compensation angle from the rotation position of the rotor at the first time point is formed in the second control cycle, wherein
• the processor sets a target angular acceleration of the rotor according to a predetermined angular acceleration pattern showing a temporal change in the angular velocity,
• the voltage controller controls the voltage to be applied to the coil such that the angular acceleration of the rotor becomes closer to the target angular acceleration, and
• the processor obtains, as the angular acceleration of the rotor, an angular acceleration in a time period from the first time point to the second control cycle, the angular acceleration being shown by the predetermined angular acceleration pattern.

A motor controller for controlling a motor according to a control cycle, the motor including a coil that generates a rotating magnetic field and a rotor that is formed using a permanent magnet and rotates by the rotating magnetic field generated by the coil, the motor controller comprising:

• a processor;
• and
• a voltage controller,
• the processor obtaining a rotation position and an angular velocity of the rotor at a first time point,
• based on an angular acceleration of the rotor, the angular velocity of the rotor at the first time point and a time length of the control cycle, the processor calculating a compensation angle by which the rotor advances from the first time point to a second control cycle subsequent to a first control cycle including the first time point,
• the voltage controller controlling a voltage to be applied to the coil such that a rotating magnetic field based on a rotation position of the rotor advanced by the compensation angle from the rotation position of the rotor at the first time point is formed in the second control cycle, wherein the processor obtains load information showing a magnitude of a load applied to the motor, and estimates the angular acceleration of the rotor based on a change in the magnitude of the load shown by the load information.

A motor controlling method of controlling a motor according to a control cycle, the motor including a coil that generates a rotating magnetic field and a rotor that is formed using a permanent magnet and rotates by the rotating magnetic field generated by the coil, the motor controlling method comprising:

• obtaining, by a processor, a rotation position and an angular velocity of the rotor at a first time point;
• based on an angular acceleration of the rotor, the angular velocity of the rotor at the first time point and a time length of the control cycle, calculating, by the processor, a compensation angle by which the rotor advances from the first time point to a second control cycle subsequent to a first control cycle including the first time point;
• and
• controlling a voltage to be applied to the coil such that a rotating magnetic field based on a rotation position of the rotor advanced by the compensation angle from the rotation position of the rotor at the first time point is formed in the second control cycle, wherein
• the processor obtains load information showing a magnitude of a load applied to the motor, and estimates the angular acceleration of the rotor based on a change in the magnitude of the load shown by the load information.