Claims
- 1. A motor current detection method comprising:
- driving a motor according to a periodic PWM signal having an ON time period and an OFF time period for each pulse thereof; and,
- detecting a motor current I of the motor from instantaneous current values I1 and I2 of the motor at respective intermediate time points of the ON and OFF time periods of the periodic PWM signal and from a duty factor .alpha. of the PWM signal.
- 2. A method as recited in claim 1, wherein the detected motor current I is determined in accordance with the following equation:
- I=.alpha.I1+(1-.alpha.)I2.
- 3. A motor control method comprising:
- driving a motor according to a periodic PWM signal having an ON time period and an OFF time period for each pulse thereof;
- detecting a motor current I of the motor from instantaneous current values I1 and I2 of the motor at respective intermediate time points of the ON and OFF time periods of the periodic PWM signal and from a duty factor .alpha. of the PWM signal; and
- controlling said driving of the motor according to the detected motor current I.
- 4. A method as recited in claim 3, wherein the detected motor current I is determined in accordance with the following equation:
- I=.alpha.I1+(1-.alpha.)I2.
- 5. A method as recited in claim 4, wherein said controlling step includes comparing a desired motor current with the detected motor current I, and adjusting the duty factor .alpha. of the PWM signal in accordance with the thus compared desired motor current and detected motor current I.
- 6. A motor control method comprising:
- a first step of repeatedly generating a periodic PWM signal having an ON time period and an OFF time period for each pulse period thereof and having a duty factor .alpha. which is set in accordance with a given current command value;
- a second step of driving a motor using the periodic PWM signal repeatedly generated in said first step;
- a third step of measuring instantaneous current values I1 and I2 of the motor at respective intermediate time points of the ON and OFF time periods of the periodic PWM signals, and calculating a detected motor current I=.alpha.I1+(1-.alpha.) I2; and,
- a fourth step of controlling the motor by adjusting the duty factor .alpha. of the PWM signal repeatedly generated in said first step in accordance with a difference between the given current command value and the detected motor current I.
Priority Claims (1)
Number |
Date |
Country |
Kind |
1-300445 |
Nov 1989 |
JPX |
|
Parent Case Info
This application is a continuation of now abandoned application Ser. No. 07/615,452, filed Nov. 19, 1990.
US Referenced Citations (5)
Continuations (1)
|
Number |
Date |
Country |
Parent |
615452 |
Nov 1990 |
|