Motor controller, image forming apparatus and motor controlling method

Patent metadata

Field	Value
Publication number	US-10651765-B2
Application number	US-201815888934-A
Country	US
Kind code	B2
Filing date	Feb 5, 2018
Priority date	Feb 14, 2017
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

A motor controller includes: a velocity calculation unit for obtaining an angle θ(n), which shows a rotation position, and an angular velocity ω(n) of a rotor at a time point n; a compensation amount calculation unit for calculating a compensation angle Δθ by which the rotor advances from the time point n to a (n+1)th control cycle (a control cycle starting from a time point n+1), based on an angular acceleration a(n) of the rotor, an angular velocity ω(n) of the rotor at the time point n and a time length T of the control cycle; and a PWM inverter for controlling a voltage to be applied to a coil such that a rotating magnetic field based on a rotation position of the rotor advanced by the compensation angle Δθ from the rotation position of the rotor at the time point n is formed in the (n+1)th control cycle.

First claim

What is claimed is:

1. 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,
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 the target angular acceleration as the angular acceleration of the rotor.

2. The motor controller according to claim 1 , wherein
the processor sets the target angular acceleration for each control cycle, and
the processor calculates the compensation angle based on the target angular acceleration in the first control cycle and the target angular acceleration in the second control cycle, each of the target angular acceleration in the first control cycle and the target angular acceleration in the second control cycle being set by the processor.

3. The motor controller according to claim 1 , wherein the processor obtains a value of a current flowing through the coil, and estimates the angular acceleration of the rotor based on a change in the value of the current.

4. 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.

5. 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.

6. 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.

7. The motor controller according to claim 6 , 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.

8. The motor controller according to claim 7 , wherein
when the angular velocity of the rotor at the first time point is defined as ω(n), the angular acceleration of the rotor is defined as a(n), a time length of the control delay time period is defined as Ta, and the compensation angle is defined as Δθ, the processor calculates the compensation angle according to an equation:
Δθ=ω( n )× Ta+a ( n )× Ta

Assignees

• Konica Minolta Inc

Inventors

• Suzuki Daichi
• Tachibana Yuta
• Yoshikawa Hiroyuki
• Koide Yasuhiro

Classifications

• H02P21/22

  Current control, e.g. using a current control loop · CPC title

• H04N1/00928

  Initialisation or control of normal start-up or shut-down, i.e. non failure or error related · CPC title

• H02P6/17

  and for generating speed information · CPC title

• H02K1/14

  Stator cores with salient poles · CPC title

• H02K1/2786

  Outer rotors · CPC title