Stepping motor controlling device

Abstract

A stepping motor controlling device according to the present invention includes lead angle computing means which computes a lead angle according to the load torque current deviation of the stepping motor, adding means which adds an angle command to the lead angle to determine a winding exciting angle and voltage applying means which applies a voltage according to the winding exciting angle to the stepping motor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a stepping motor controlling device according to the present invention;

FIG. 2 shows a lead angle controller in the stepping motor controlling device illustrated in FIG. 1;

FIG. 3 shows another stepping motor controlling device according to the present invention;

FIG. 4 shows an angle estimator in the stepping motor controlling device illustrated in FIG. 3;

FIG. 5 shows another stepping motor controlling device according to the present invention;

FIG. 6 shows a magnetic pole position compensator in the stepping motor controlling device illustrated in FIG. 5; and

FIG. 7 and FIG. 8 are explanatory drawings for the stepping motor controlling device illustrated in FIG. 5 and FIG. 6.

Claims

1. A stepping motor controlling device for controlling a stepping motor according to an angle command comprising: lead angle computing means which computes a lead angle according to the load torque current deviation of said stepping motor;adding means which adds said angle command to said lead angle to determine a winding exciting angle; andvoltage applying means which applies a voltage according to said winding exciting angle to said stepping motor.

2. The stepping motor controlling device according to claim 1, wherein said lead angle computing means comprises coordinate transformation means which determines said load torque current deviation from the angle of said stepping motor and the current deviation of said voltage supplying means.

3. The stepping motor controlling device according to claim 2, wherein angle detecting means which detects said angle of said stepping motor is provided to use the angle detected by said angle detecting means as said angle of said stepping motor.

4. The stepping motor controlling device according to claim 2, wherein angle estimating means which estimates said angle of said stepping motor to use the angle estimated by said angle estimating means as said angle of said stepping motor.

5. The stepping motor controlling device according to claim 1, wherein said lead angle computing means comprises adding means which adds a set angle to a value according to said load torque current deviation.

6. The stepping motor controlling device according to claim 1, wherein said lead angle computing means comprises: limiting means which directly outputs a value according to said load torque current deviation when said value according to said load torque current deviation is less than a predetermined angle and outputs the predetermined angle when said value according to said load torque current deviation is said predetermined angle or larger; andadding means which adds a set angle to the output of said limiting means.

7. The stepping motor controlling device according to claim 6, wherein said predetermined angle is 100 to 140 degrees.

8. The stepping motor controlling device according to claim 5, wherein said set angle is 0 to 90 degrees.

9. The stepping motor controlling device according to claim 1 comprising a magnetic pole position compensator which outputs a first maximum current command when said stepping motor starts, outputs a second maximum current command, detects a first angle when said first maximum current command is output and a second angle when said second maximum current command is output and outputs the compensation value of said angle command using data on difference between said first angle and said second angle.