JPH07143796A - Drive controller for pulse motor - Google Patents

Abstract

PURPOSE:To realize stabilized driving by specifying the output from a pattern generator generating a function output being selected arbitrarily by the frequency of a command pulse train and controlling the exciting current of a pulse motor variably thereby sustaining the torque at a substantially constant level over the entire rotational speed range. CONSTITUTION:An excitation command value, i.e., a command voltage Vomega, of a pulse motor 6 is an output from a pattern generator 1 generating a function output selected arbitrarily from the frequency fM of a rotational speed command train for the pulse motor 6 and the output is employed as a command value for the pulse motor 6 in the variable control of exciting current. Since the exciting current of the pulse motor 6 can be regulated in the vicinity of resonance frequency, oscillation of torque is suppressed. Consequently, the oscillation of output torque from the pulse motor can be suppressed to an extent causing no practical problem and the pulse motor can be driven in safety over the entire rotational speed range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control device for a pulse motor used for positioning automatic machinery and office automation equipment, and as a drive device for a speed control device.

[0002]

2. Description of the Related Art In a conventional pulse motor, in a pulse motor drive controller for controlling a current for exciting a winding to an arbitrary designated value, the command value is constant over the entire rotation speed range of the pulse motor. The constant current method is used. FIG. 3 is a configuration diagram showing an example thereof, 2 is a calculator, 3 is a proportional amplifier, 4 is a gate circuit, 5 is a transistor, 6 is a pulse motor, and 7 is a resistor.

[0003]

However, there are the following problems. (1) The torque is large at low speed, but the drive torque tends to be insufficient at high speed. If a large current is applied in order to obtain the required shaft output torque in order to compensate for this shortage, the current becomes unnecessarily large during low speed operation. (2) The rotation system resonates at a specific rotation speed, and the vibration of the output torque further increases. There are many occurrences of this vibration near a large torque at low speed. The present invention has been made in view of the above points, and an object of the present invention is to obtain a drive control device of a pulse motor that solves these problems.

[0004]

[Means for Solving the Problems] In other words, a means for achieving the object is a pulse motor drive controller capable of command-controlling a current for exciting a pulse motor winding to an arbitrary designated value. A drive control that variably controls the excitation current of the pulse motor by providing a pattern generator that generates a function output arbitrarily selected according to the frequency of the command pulse train that commands the rotation of the motor, and use that output as the command value of the pulse motor excitation current. It relates to the device.

In this device, since the exciting current optimum for the rotational speed of the pulse motor is applied over the entire rotational speed of the pulse motor, the conventional problems can be solved. Further, the output torque of the pulse motor oscillates near a specific resonance speed, but by reducing the excitation current value of the pulse motor near this resonance speed, torque vibration can be reduced to a level that does not pose a practical problem. it can.

In the above-mentioned apparatus, the response time of the current control system for controlling the excitation current is not taken into consideration, so there is a possibility that the current command control may not be in time for the rotation command. In this case, control compatibility can be achieved by delaying the pulse commanding the rotation speed of the pulse motor for a time corresponding to the response of the current control system and adding a mechanism for transmitting the rotation command pulse.

[0007]

With such a solution, the optimum current is supplied to the excitation winding of the pulse motor, so that the pulse motor can be stably driven by maintaining a substantially uniform torque over the entire rotation speed range. it can.

[0008]

An embodiment of the present invention will be described in detail below with reference to the drawings. 1 is a block diagram showing an embodiment of the present invention, FIG.
Is a characteristic diagram thereof. In FIG. 1, 1 is a pattern generator of the present invention, 2 is a calculator, 3 is a proportional amplifier, 4 is a gate circuit, 5 is a transistor, 6 is a pulse motor, 7 is a resistor, Vc is a power supply voltage, and Vi is a feedback voltage. Therefore, in this embodiment, PWM control is performed by bipolar drive.

That is, the command voltage Vω, which is the exciting current command value of the pulse motor 6, is generated by the pattern generator 1 that generates a function output arbitrarily selected according to the frequency fM of the command sequence that commands the rotation speed of the pulse motor 6. Is the output. In the device configured as described above, it becomes possible to adjust the exciting current value of the pulse motor 6 in the vicinity of the resonance frequency, so that the torque vibration is reduced. The pattern generator 1 is configured to generate a function output arbitrarily selected according to the frequency of a command pulse train that commands the rotation of the pulse motor 6, and the output is used as a command value of the exciting current of the pulse motor 6. The excitation current of the pulse motor 6 is variably controlled.

[0010]

As described above, according to the present invention, it is possible to reduce the vibration of the output torque of the pulse motor to such an extent that there is no practical problem, and to drive the pulse motor stably in the entire rotation speed range. can do. It should be noted that the example in which the driving of the pulse motor is applied has been described in the present embodiment, but the present invention is not limited to this, and it is needless to say that the same effect can be obtained by using PWM control of various motors.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing the embodiment of FIG.

FIG. 3 is a configuration diagram showing an example of a conventional constant current chopper method.

[Explanation of symbols]

 1 pattern generator 2 arithmetic unit 3 proportional amplifier 4 gate circuit 5 transistor 6 pulse motor 7 resistor

Front page continued (72) Inventor Takashi Koga 3-2-8 Terano, Ayase City, Kanagawa Prefecture (72) Iwao Shibata, 2-17-1, Tsudanuma, Narashino City, Chiba Chiba Institute of Technology

Claims (3)

[Claims] 1. A drive control device for a pulse motor for command-controlling a current for exciting a pulse motor winding to an arbitrary specified value, wherein a function output arbitrarily selected by a frequency of a pulse train commanding rotation of the pulse motor is generated. A drive control device for a pulse motor, characterized in that a pattern generator is provided, and its output is used as a command value for an exciting current of the pulse motor. 2. The pulse motor driving device according to claim 1, further comprising means for reducing an exciting current designation value of the pulse motor near a pulse train frequency corresponding to a specific rotation speed at which output torque vibrates. Drive controller. 3. The method according to claim 1, further comprising means for transmitting a rotation command pulse obtained by delaying a pulse for commanding rotation of the pulse motor by a time corresponding to a response time of a current control system for command controlling the exciting current. Item 2. A pulse motor drive controller according to Item 2.