KR100190709B1 - Step motor speed control method using harmonic motion - Google Patents

Abstract

The present invention utilizes harmonic motion to realize a more stable motor control by preventing harmonic motions from using the harmonic motion to prevent the time derivative of acceleration from the acceleration of the motor to the constant velocity section and the deceleration section at the constant velocity to be infinite. It relates to a speed control method of a step motor.

The present invention is a process of forming a harmonic diagram for the maximum speed by drawing a circle with a diameter of the maximum speed of the motor, and then projecting by dividing equally at a predetermined angle to have the number of pulses driving the semicircle,

The step motor is controlled by the data extracted by the harmonic diagram.

Therefore, under the same conditions, the driving of the pulse motor using the harmonic motion of the present invention achieves an improved speed control effect because the jerk causing the sudden change of inertia force is maintained at a constant constant value.

Description

Speed Control Method of Step Motor Using Harmonic Motion

1 is a control circuit block diagram of a step motor to which the present invention is applied.

2 (a) to 2 (c) are speed, acceleration, and jerk graphs showing a speed control method of a conventional step motor.

3 (a) and (b) are speed and acceleration graphs for explaining the principle of speed control of a step motor using harmonic motion according to the present invention.

4 (a) to (c) are speed, acceleration, and jerk graphs illustrating a speed control method of a step motor using a harmonic motion according to the present invention.

* Explanation of symbols for the main parts of the drawings

10: control unit 20: step motor drive unit

30: step motor

The present invention relates to a method of controlling a stepper motor, and in particular, an acceleration section for accelerating a stationary motor to a maximum speed is performed by harmonic motion (speed and acceleration) for each rising section of acceleration, equivalent speed section, and falling section of acceleration. The present invention relates to a method for controlling the speed of a step motor using harmonic motion, which can be used to obtain more stable motor control by preventing the breakout of the motor caused by acceleration / deceleration of the motor.

In the accompanying drawings, FIG. 1 shows a general circuit block diagram of the step motor 30 control. Referring to FIG. 1, a control unit is provided at a signal input terminal of a step motor driver 20 to which a DC power is supplied. When a predetermined pulse is applied from the 30, the step motor 30 is rotated by a predetermined angle. Therefore, when the pulse is continuously given, the step motor 30 is rotated in proportion to the pulse frequency.

In particular, as shown in FIG. 2A, in the case of general speed control having an acceleration section (0-t1), a constant speed section (t1-t2), and a deceleration section (t2-t3), the controller 10 controls the acceleration section. In (0-t1), acceleration control is performed while reducing the interval of output pulse.In constant velocity section (t1-t2), constant velocity control is performed by constant pulse interval, and in deceleration section (t2-t3), pulse is controlled. Deceleration control is performed by increasing the interval of.

Therefore, the acceleration of the motor rises in the acceleration section (0-t1), constant in the constant velocity section (t1-t2), and falls in the deceleration section (t2-t3) as shown in FIG.

However, such trapezoidal acceleration, constant speed and deceleration control of the step motor 30 is harmonic when driven under a load applied to the rotating shaft of the step motor 30 as shown in FIG. The jerk (j = Δa / Δt; time differential amount of acceleration) used for motion becomes infinity (± ∞) in the interval t1 between acceleration and constant velocity and the interval t2 between constant velocity and deceleration, respectively. There was a problem that the sudden inertial force is caused to the load of the step motor 30, the possibility of breakout of the step motor 30 becomes high.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and therefore, an object of the present invention is to smoothly convert a part causing a sudden change in acceleration by using a harmonic motion (curve) in controlling a step motor, The present invention provides a method for controlling the speed of a step motor using a harmonic motion that eliminates abrupt changes in inertia by preventing the jerk value from becoming a constant value.

According to the present invention for achieving the object as described above, in the method for controlling the speed of a step motor using harmonic motion, a circle having a maximum speed of a predetermined motor as a diameter is obtained, and the circle is a right semicircle. A first step of drawing a harmonic diagram by drawing equal equal lines at equal angles and extending the points where the equal lines and the arcs of the right semicircle meet on a horizontal line; A second step of obtaining an acceleration rising section, an equivalent acceleration section, and an acceleration falling section based on the harmonic diagram to obtain an acceleration section for accelerating a stationary motor to a maximum speed; A third step of generating a control signal of the motor on the basis of the obtained speed and acceleration in the section-specific acceleration section and controlling the speed of the motor; Characterized in that made.

Hereinafter, a method of controlling a speed of a step motor using harmonic motion according to the present invention will be described with reference to the accompanying drawings.

3 (a) and 3 (b) are speed and acceleration graphs for explaining the speed control principle of a step motor using harmonic motion according to the present invention. Referring to FIG. 3, first, FIG. As shown in Fig. 1, in the first step, a circle whose diameter is the maximum speed of the motor to be maximized is drawn, and then the right semicircle of the circle is drawn in order to have a pulse number for driving the motor in the right semicircle of the circle. The equal projection at the same angle produces a harmonic diagram for the desired maximum speed.

More specifically, draw an equal line dividing the right semicircle of the circle at the same angle and extend each point where the bisector and the arc of the right semicircle meet in parallel to each other on the horizontal line to the velocity (V) -time (t) diagram. The harmonic diagram as shown in Fig. 3 (a) is obtained.

Accordingly, a time-specific speed (V) curve is formed as shown in FIG. 3 (a), and the graph shown in FIG. 3 (a) is a graph for performing acceleration control at maximum speed for the motor which is stopped. In the acceleration section t0-t1 of FIG. 3 (a), it can be seen that the velocity V slowly increases from the zero point to the maximum velocity.

In the second step, based on the harmonic diagram, the acceleration section for accelerating the stopped motor to the maximum speed is the acceleration rising section (0-t01), the equivalent acceleration section (t01 to t02), and the acceleration falling section (t02 to t1). ), And the velocity (V) and acceleration (a) for each section.

Specifically, referring to FIG. 3 (a), it can be seen that the acceleration is increased up to a certain section in the velocity graph of FIG. 3 (a), and that the acceleration is constant up to a certain section, and It can be seen that the acceleration is falling, where the acceleration rising section is the acceleration rising section (0-t01), the constant acceleration section is the constant acceleration section (t01-t02) and the acceleration falling section is the acceleration falling section It is shown as (t02-t1).

In this way, the acceleration section t0-t1 according to the present invention is subdivided into an acceleration rising section (0-t01), an equivalent acceleration section (t01-t02), and an acceleration falling section (t02-t1), and also the acceleration according to the present invention. The graph corresponding to the section has a gentle curved shape, as shown in FIG. 3 (a), unlike the linear acceleration section graph shown in FIG. 2 (a).

As shown in FIG. 3 (b), the acceleration gradually increases gradually in the acceleration rising section (0-t01), and the acceleration is constant in the equivalent acceleration section (t01-t02). And, it can be said that the acceleration gradually decreases in the acceleration falling section (t02-t1).

In the third step, the control signal of the motor is generated based on the obtained speed V and the acceleration a in each section, and the speed of the motor is controlled. By determining the number of pulses for controlling the speed of the motor based on this and providing a control signal, the motor speed in the acceleration section can be controlled.

On the other hand, the speed control method of the motor for the acceleration section (t0-t1) shown in FIG. 3 is applied to the deceleration section in the same manner, and the acceleration section (t0-t01-t02-t1) of the motor as described above. Applying the motor control principle in EAS to the deceleration section (t2-t3), the graph of the entire control section of the motor, that is, the acceleration section, the constant speed section and the deceleration section is as shown in Fig. 4 (a), In particular, the acceleration section and the acceleration section can be smoothly controlled as shown in FIG.

4 (a) to (c) are diagrams corresponding to the second to (a) to (c) of the prior art, which shows the speed, acceleration and the speed control method of the step motor control method using the harmonic motion according to the present invention As a JERK graph, referring to FIG. 4, a boundary between the acceleration section (0-t1) and the constant velocity section (t1-t2), the constant velocity section (t1-t2) and the deceleration section (t2-t3) There is no sudden speed difference at the boundary between them.

After all, if the technique of the present invention is applied to the speed control of the motor, the jerk value by the harmonic motion is constant in the acceleration section (0-t1) and the deceleration section (t2-t3) as shown in FIG. Since there is no sudden change of inertia force on the load of the stepper motor 30 shaft, it is possible to obtain an improved voltage maximum value than that of a typical trapezoidal stepper motor drive.

As described above, the present invention generally does not require the inertia force in the case of driving the stepper motor itself (when there is no load). When the acceleration-constant-deceleration using the conventional trapezoidal type is applied, it is concluded that the voltage must be increased to prevent breakout of the inertia force of the load of the pulse motor.

Therefore, under the same conditions, driving of a pulse motor using harmonic motion results in an improved speed control effect because the jerk causing a sudden change of inertia force is maintained at a constant constant value.

The above description is only a description of one embodiment of the present invention, the present invention is capable of various changes and modifications within the scope of the configuration.

Claims (1)

(Correction) in the speed control method of the step motor using harmonic motion, Obtain a circle whose diameter is the maximum speed of a preset motor, draw an equal line dividing the right half circle of the circle at the same angle, and extend the lines parallel to each other on the horizontal line at each point where the arc of the equal line and the right half circle meet. Drawing a harmonic diagram by drawing a first step; Based on the harmonic diagram, the plastic section for accelerating the stationary motor to the maximum speed is divided into the acceleration rising section (0 to t01), the equivalent acceleration section (t01 to t02), and the acceleration falling section (t02). t1), and a second step of obtaining velocity V and acceleration a for each section; A third step of controlling a speed of the motor by generating a control signal of the motor based on the obtained speed V and the acceleration a in the section-specific acceleration section; Speed control method of a step motor using a harmonic motion characterized in that consisting of.