Method and apparatus for controlling a digital controlled brushless motor

• US 4,376,262 A
• Filed: 02/26/1981
• Issued: 03/08/1983
• Est. Priority Date: 02/29/1980
• Status: Expired due to Fees

• Current Assignee: Fuji Electrochemical Company Limited
• Original Assignee: Fuji Electrochemical Company Limited
• Inventors: Oishi, Wataru, Okuda, Masanao
• Primary Examiner(s): Truhe, J. V.
• Assistant Examiner(s): BERGMANN, SAUL
• Application Number:
  US06/238,485
• Time in Patent Office: 740 Days
• Field of Search: 318/696, 318/685, 318/138, 318/254, 318/254 A
• US Class Current: 318/696
• CPC Class Codes: H02P 6/12 Monitoring commutation; Providing indication of commutation failure
• CPC Class Codes: H02P 8/42 characterised by non-stepper motors being operated step by step

Abstract

There are provided a method of and an apparatus for controlling a pulse controlled brushless motor to immediately pull-in the motor to a predetermined rotational speed. The method has the steps of encoding rotational condition of a rotor into an electric signal, detecting the encoded signal to determine whether the rotor is in rotation or not, synchronizing a signal of a pull-in pulse rate with a clock pulse when the rotor is not in rotation and synchronizing the encoded signal with the clock pulse when the rotor is in rotation to form an input pulse train. The input pulse train is supplied to a peripheral circuit to excite the motor.

Claims

1. Method of controlling a pulse controlled brushless motor which has an electric circuit means for producing a clock pulse in a slewing region and a signal of a pull-in pulse rate, and a peripheral circuit for exciting said motor, said motor being driven at a constant rotational speed in a region of slewing pulse rate, comprising the steps of:

a. encoding a rotational condition of a rotor of the motor by means of a rotary encoder associated with the motor thereby to produce an encoded electric signal having a frequency proportional to the speed of the motor,

b. detecting the encoded electric signal to determine whether said rotor is being rotated or not,

c. synchronizing the signal of pull-in pulse rate with the clock pulse when said rotor is not being rotated, and synchronizing said encoded electric signal with said clock pulse when said rotor is being rotated, to thereby form an input pulse train, and

d. supplying said input pulse train to said peripheral circuit, whereby when a rotational speed of said rotor does not correspond to a frequency of said clock pulse, said input pulse train is formed corresponding to any one of said signal of pull-in pulse rate and said encoded electric signal.

2. Apparatus for controlling a pulse controlled brushless motor having a rotor, comprising:

a. a rotary encoder associated with said motor for producing an encoded output signal having a frequency proportional to a rotational speed of said rotor,

b. detector means for receiving said encoded output signal of said rotary encoder and detecting a rotation of said rotor,

c. a clock pulse generator for producing a clock pulse,

d. a frequency divider for dividing said clock pulse thereby to produce a pull-in signal of a pull-in pulse rate,

e. pulse train former means responsive to said detector means for alternatively combining with said clock pulse said encoder output signal or said pull-in signal to thereby form an input pulse train which, in the slewing range, generates an input pulse train that gradually effects increases in the motor speed until synchronized with said clock pulse, and in the pull-in range, generates an input pulse train having a frequency corresponding to said pull-in signal, and

f. peripheral circuit means having an excitation mode generator for receiving said input pulse train and excitating said motor.

3. An apparatus for controlling a pulse controlled brushless motor having a rotor, comprising:

a. a rotary encoder associated with said motor for producing an output having a frequency corresponding to a rotational speed of said rotor,

b. detector means for receiving said output of said rotary encoder and detecting a rotation of said rotor, in which said detector means consists of a first monostable multivibrator triggered by the output of said rotary encoder,

c. a clock pulse generator for producing a clock pulse,

d. a frequency divider for dividing said clock pulse to a pull-in pulse rate,

e. pulse train former means for combining an output of said rotary encoder, an output of said detector means and an output of said frequency divider to synchronize the combined signal with said clock pulse to thereby form an input pulse train, and

f. peripheral circuit means having an excitation mode generator for receiving said input pulse train and excitating said motor.

4. An apparatus for controlling a pulse controlled brushless motor having a rotor, comprising:

a. a rotary encoder associated with said motor for producing an output having a frequency corresponding to a rotational speed of said rotor,

b. detector means for receiving said output of said rotary encoder and detecting a rotation of said rotor,

c. a clock pulse generator for producing a clock pulse,

d. a frequency divider for dividing said clock pulse to a pull-in pulse rate,

e. pulse train former means for combining an output of said rotary encoder, an output of said detector means and an output of said frequency divider to synchronize the combined signal with said clock pulse to thereby form an input pulse train, in which said pulse train former means has a first AND gate, second AND gate, OR gate connected at its input terminals to said first AND gate and said second AND gate, and first D-type flip-flop circuit connected at its D terminal to an output terminal of said OR gate, said flip-flop circuit being clocked by the clock pulse, and

f. peripheral circuit means having an excitation mode generator for receiving said input pulse train and excitating said motor.

5. An apparatus for controlling a pulse controlled brushless motor having a rotor, comprising:

a. a rotary encoder associated with said motor for producing an output having a frequency corresponding to a rotational speed of said rotor,

b. detector means for receiving said output of said rotary encoder and detecting a rotation of said rotor,

c. a clock pulse generator for producing a clock pulse,

d. a frequency divider for dividing said clock pulse to a pull-in pulse rate,

e. pulse train former means for combining an output of said rotary encoder, an output of said detector means and an output of said frequency divider to synchronize the combined signal with said clock pulse to thereby form an input pulse train, in which said frequency divider has a second monostable multivibrator and a second D-type flip-flop circuit, said second D-type flip-flop circuit having a D terminal connected to an inverted Q terminal, thereby performing a toggle operation, an output terminal of said second monostable multivibrator being connected to a CK terminal of said second D-type flip-flop circuit, and

f. peripheral circuit means having an excitation mode generator for receiving said input pulse train and excitating said motor.

6. An apparatus for controlling a pulse controlled brushless motor having a rotor, comprising:

a. a rotary encoder associated with said motor for producing an output having a frequency corresponding to a rotational speed of said rotor,

b. detector means for receiving said output of said rotary encoder and detecting a rotation of said rotor,

c. a clock pulse generator for producing a clock pulse,

d. a frequency divider for dividing said clock pulse to a pull-in pulse rate,

e. pulse train former means for combining an output of said rotary encoder, an output of said detector means and an output of said frequency divider to synchronize the combined signal with said clock pulse to thereby form an input pulse train, and

f. peripheral circuit means having an excitation mode generator for receiving said input pulse train and excitating said motor in which said excitation mode generator has a first J-K flip-flop and a second J-K flip-flop, a CK input terminals of the first and second flip-flop being connected to said pulse train former means so that said input pulse train is fed to said CK input terminals, a J input terminal and a K input terminal of said first flip-flop being connected to an inverted Q output terminal and a Q outpute terminal, respectively, of said second flip-flop, a J input terminal and a K input terminal of said second flip-flop being connected to a Q output terminal and an inverted Q output terminal, respectively, of said first flip-flop.

7. An apparatus for controlling a pulse controlled brushless motor having a rotor, comprising:

a. a rotary encoder associated with said motor for producing an output having a frequency corresponding to a rotational speed of said rotor,

b. detector means for receiving said output of said rotary encoder and detecting a rotation of said rotor,

c. a clock pulse generator for producing a clock pulse,

d. a frequency divider for dividing said clock pulse to a pull-in pulse rate in which said frequency divider produces an output having a frequency lower than a maximum pull-in pulse rate of the motor,

e. pulse train former means for combining an output of said rotary encoder, an output of said detector means and an output of said frequency divider to synchronize the combined signal with said clock pulse to thereby form an input pulse train, and

f. peripheral circuit means having an excitation mode generator for receiving said input pulse train and excitating said motor.

8. Apparatus for controlling a pulse controlled brushless motor having a rotor, comprising:

a. a rotary encoder associated with said motor for producing an encoded output signal proportional to the rotational speed of the motor,

b. detector means for receiving said encoded output signal of said rotary encoder and detecting a rotational condition of said rotor,

c. a first pulse generator for producing a clock pulse,

d. a second pulse generator for producing a pull-in output signal having a frequency lower than a maximum pull-in pulse rate of the motor,

e. pulse train former means responsive to said detector means for alternatively combining with said clock pulse said encoded output signal or said pull-in signal to thereby form an input pulse train which, in the slewing range, generates an input pulse train that gradually effects increases in the motor speed until synchronized with said clock pulse, and in the pull-in range, generates an input pulse train having a frequency corresponding to said pull-in signal, and

f. peripheral circuit means having an excitation mode generator for receiving the input pulse train and exciting said motor.