JPS6142295A - Drive controlling method for pulse motor - Google Patents

Abstract

PURPOSE:To abruptly control to accelerate or decelerate without causing a stepout phenomenon by varying an exciting voltage to high voltage when the change rate of the frequency of the drive pulse exceeds the prescribed value. CONSTITUTION:When a pulse motor 12 is abruptly accelerated, the frequency of an electric pulse supplied to the motor 12 is abruptly varied. The variation of the frequency is detected by a pulse frequency change rate detector 4, the output of the detector 4 conducts a switching circuit 6 and applies a high voltage to a pulse motor drive circuit 10. When the voltage becomes high, the magnetic force of the rotor of the motor 12 increases to stop the stepout of the motor 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for controlling the drive of a pulse motor used in automatic drawing machines, automatic focusing devices of cameras, and the like.

[Prior Art] The types of pulse motor drive control methods can be roughly divided into two types: a constant current drive method in which the pulse motor is driven by applying a constant current, and a constant voltage drive method in which the pulse motor is driven by applying a constant voltage. exists.

[Problem that the invention seeks to solve]

When an automatic drawing machine or the like is driven by a pulse motor, the pulse motor is controlled to accelerate and decelerate when the moving parts of the machine start and stop. During this acceleration and deceleration, the inertial force of the movable portion acts largely on the output shaft of the pulse motor. Therefore,
When the pulse motor accelerates, as shown in Figure 3, the next driving electric pulse is supplied to the stator excitation winding of the pulse motor before the rotor of the pulse motor rises to the predetermined rotation angle θO. , a phenomenon occurs in which the rotation angle of the rotor of the pulse motor does not accurately follow the driving electric pulse, that is, a step-out phenomenon occurs. Also, when the pulse motor decelerates, the rotor of the pulse motor rotates beyond a predetermined angle due to inertia, and the rotation of the rotor no longer follows the electric pulses, causing a step-out phenomenon in the pulse motor. I end up.

The above-mentioned step-out phenomenon of the pulse motor occurs regardless of whether a constant current or constant voltage drive system is adopted, so it has been impossible to rapidly accelerate and decelerate the movable parts of the machine using the pulse motor. The present invention aims to eliminate the above-mentioned defects.

[Means to solve problems]

In order to achieve the above object, the present invention provides a method for driving and controlling a pulse motor by supplying electric pulses to each phase of a stator excitation winding of the pulse motor. When the rate of change exceeds a predetermined value, a predetermined high excitation voltage higher than the steady excitation voltage is supplied to each phase of the stator excitation winding of the pulse motor.

[Effect]

Therefore, when the pulse motor accelerates or decelerates, the stator excitation voltage of the pulse motor increases, and the magnetic force on the rotor increases. This prevents the pulse motor from stepping out, so the pulse motor is rapidly accelerated or decelerated. The movable parts of the machine can be controlled by rapidly accelerating and decelerating them.

〔Example〕

The configuration of the present invention will be explained below with reference to the accompanying drawings.

In Fig. 1, 2 is a pulse distribution circuit, and the input terminal of this is a pulse motor drive pulse generation circuit (not shown).
It is connected to the output terminal of 4 is a pulse frequency change rate detection circuit connected to the pulse motor drive pulse generation circuit, and output terminals A and B of this are connected to the switching circuit 6.
．． It is connected to the control end of 8. The pulse frequency change rate detection circuit 4 detects the rate of change in the frequency of the pulse input thereto, that is, the acceleration/deceleration, and when the rate of change exceeds a set value, the output terminal A becomes II I I + the output terminal B becomes Pa0'. ", and when the rate of change does not reach the set value, the output terminal A outputs "
0" output terminal B is configured to output "]". One end of the switching circuit 6 is connected to the high voltage supply circuit, and the other end is connected to the pulse motor drive circuit 10. One end of the circuit 8 is connected to a steady voltage supply circuit, and the other end is connected to a pulse motor drive circuit 10.

The switching circuits 6 and 8 are connected to these control terminals by II.
I When II signal is input, conduction (ON) L, LL
It is configured to be shut off (OFF) when OII is input. The pulse motor drive circuit 10 drives the pulse motor 12 based on the output voltage of the switching circuit 6 or 8 and the output command pulse signal of the pulse distribution circuit 2.
The pulse motor 12 is driven by supplying driving electric pulses to each phase of the stator winding.

Next, the operation of this embodiment will be explained.

To explain the automatic drawing machine, its pulse motor 12
As shown in FIG. 2, when the movable part, ie, the head, is moved a predetermined distance, it is first subjected to rapid acceleration control and then shifts to a steady speed. When the head approaches the stop position by a predetermined distance, it is suddenly decelerated.
Stops at a predetermined stop position. When the pulse motor 12 is rapidly accelerated, the frequency of the electric pulses supplied to the pulse motor 12 changes rapidly. The pulse frequency change rate detection circuit 4 detects this change in frequency, and the output terminal A of the circuit 4 outputs u 1 rr. Also, output terminal B outputs If OII. As a result, the switching circuit 6 becomes conductive, the switching circuit 8 is cut off, and the pulse motor drive circuit 10
high voltage is supplied to The rise time of the rotor of the pulse motor 12 is inversely proportional to the magnitude of the voltage of the electric pulse applied to the stator of the pulse motor. That is, in FIG. 3, if the predetermined rotation angle of the rotor of the pulse motor 12 corresponding to one electric pulse is 00, then if you want to shorten the time t1 for the rotor to reach the angle θO by one electric pulse, the pulse motor If you want to increase the excitation voltage to 2 and lengthen the time t1, you can lower the excitation voltage.

As the excitation voltage increases, the magnetic force applied to the rotor of the pulse motor 12 becomes stronger, and the adjustment of the pulse motor 12 is prevented. When a high voltage is supplied to the pulse motor 12, the transient response characteristic of the rotor to electric pulses draws a curve as shown by the dotted line in FIG. Assuming that the curve shown by the solid line in FIG. 3 is the transient response characteristic at a steady voltage, when an electric pulse is supplied to the pulse motor 12 at time tl' in a steady voltage state, in this state the rotor is Since the value θO has not been reached, a step-out phenomenon will occur in the pulse motor 12. However, in a high excitation voltage state, the rotor has already reached θ0 at t1', so the pulse motor 1
2 does not go out of step. When the pulse motor 12 rotates at a constant speed, the switching 6 is cut off, the switching circuit 8 is turned on, and a steady voltage is supplied to the pulse motor drive circuit 10. When the pulse motor 12 is decelerated, a high voltage is supplied to the circuit 10 via the switching circuit 6. When the pulse motor is decelerated, an inertial force acts on the output shaft of the pulse motor due to the weight of the head, etc., and the rotor of the pulse motor 12 tries to rotate faster than the timing of the electric pulse. However, since the rotor is attracted to the stator side by the strong magnetic force caused by the high voltage, the rotor is regulated by the magnetic force, and instead of rotating at high speed due to the inertial force, it rotates at a reduced speed following the timing of the electric pulses. do.

〔effect〕

As described above, the present invention changes the excitation voltage of the pulse motor to a predetermined high voltage when the rate of change in the frequency of the drive pulse exceeds a predetermined value. Adjustment can be controlled, and movable parts such as automatic drawing machines can be controlled at high speed.

[Brief explanation of the drawing]

The drawings show preferred embodiments of the present invention, in which FIG. 1 is a block circuit diagram, FIG. 2 is an explanatory diagram of operation, and FIG. 3 is a transient response characteristic diagram of a pulse motor. 2... Pulse distribution circuit, 4... Pulse frequency change rate detection circuit, 6, 8... Switching circuit,
]0...Pulse motor drive circuit, 12...Pulse motor

Claims (1)

[Claims] (1) In a method of driving and controlling a pulse motor by supplying electric pulses to each phase of the stator excitation winding of the pulse motor, the rate of change in the frequency of the electric pulses supplied to the pulse motor exceeds a predetermined value. and a pulse motor drive control method, characterized in that a predetermined high excitation voltage higher than a steady excitation voltage is supplied to each phase of a stator excitation winding of the pulse motor.