JPS61240898A - Motor drive control system - Google Patents

Abstract

PURPOSE:To control two types of motors with high responsiveness and high efficiency employed with the merits of the two kinds of motors by controlling the speed of a DC motor at rotation control mode time, and controlling near the stopping position by a pulse motor. CONSTITUTION:A servo amplifier 28 amplifies an input error signal to drive a DC motor 1, a signal for detecting by a current detector 29 the drive current flowed to the winding of the motor 1 to the amplifier 28 to control the speed. The motor 1 is driven by a speed control mode signal output from a pulse width controller 22 to the vicinity of the desired stopping position, switched to a damping steady mode from the speed control mode immediately before the stopping position, a switch circuit 26 is deenergized to energize a pulse motor exciter 30. A pulse motor 5 rotates by one incremental angle determined from the relation between the exciting phase excited by the exciter 30 and the pole of a rotor, and stops.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a movable member drive control system in which, for example, a type wheel and carriage in a printer are driven intermittently.

Moxibustion Rice Peel 4 Conventionally, a direct current control motor, particularly a servo motor, or a pulse motor is sometimes used as a drive source in a type of printer that drives a type wheel and carriage intermittently.

When a servo motor is used as a drive source, it has the advantage of fast response and high energy efficiency. On the other hand,
Speed control requires an analog signal as a drive signal and a transducer to detect the amount of movement of the movable member, and stop control requires a position signal having a gradient relative to the desired stop position or rotation angle to the motor. Positioning control must be performed using the error signal of these signals by feeding back the drive signals, and the disadvantage is that the structure of the analog signal stabilizing device and motor drive control device used as the drive signal becomes complicated and expensive. there were.

On the other hand, when a pulse motor is used as a drive source, it has poor response and low energy efficiency compared to a servo motor, but the rotation angle per drive pulse is determined by the number of magnetic poles formed on the stator and rotor of the pulse motor. It is determined mechanically based on the relationship, and has the advantage of enabling open control, simplifying the positioning control device, and being inexpensive.

An object of the present invention is to provide a motor drive control system that takes advantage of the above two types of motors, has high responsiveness, high efficiency, and has a simple control circuit.

1. The configuration of the present invention will be described below based on specific examples.

FIG. 1 is a schematic configuration diagram to which the present invention is applied.

One end of the rotating shaft 2 of the DC motor 1 is connected to a load 9, and the other end is directly connected to an encoder disk plate 4 having slits 3 at equal intervals on the outer periphery.

A rotating shaft 6 of the pulse motor 5 is coupled to a rotating shaft 2 of the DC motor 1 via a coupling portion 7 . A light emitting element is disposed on one side facing the slit portion 3 of the encoder disk plate 4, and a light receiving element is disposed on the other side. It constitutes user 8.

FIG. 2 shows a control block diagram for executing drive control according to the present invention, and FIG. 3 is a time chart.

The movement amount and rotation direction information regarding the next target position to be reached with respect to the current position where the motor is in the stopped driving state are output from the command circuit 21 to the pulse width control circuit 22 and the pulse motor excitation circuit 30.

The pulse width control circuit 22 is composed of a ROM, etc., and reads pulses from a memory circuit 23 that stores a speed control profile preset for a unit rotation angle with respect to a movement amount, and sends the pulses as a pulse train to a phase comparison circuit 24. At the same time, a speed control mode signal and a rotation direction instruction signal are output to the switch circuit 26 and the pulse motor excitation circuit 30.

A pair of position signals A and B having a phase difference of 90 degrees from each other from the slit pulse signal obtained from the transducer 8 as the motor rotates are shaped into a sine wave or a rectangular wave by the position signal detection circuit 31 and then shaped into a sine wave or a rectangular wave by the rotation degree direction detection circuit 32. is output to. Of the pair of position signals, the position signal A is output to the pulse width control circuit 22 and the phase comparison circuit 24.The phase comparison circuit 24 outputs the input phase signal A and the pulse width control circuit 2.
Compare the phase with the pulse train from phase signal A, and if the frequency of the pulse train is higher than phase signal A, a positive error signal is sent, and if the frequency of the pulse train is lower than phase signal A, a negative error signal is sent to the low-pass filter. Output to 25. The low-pass filter 25 removes high frequency components of the input signal and outputs the signal to the switch circuit 26 and the polarity inversion circuit 27. The switch circuit 26 uses the speed control mode signal and rotation direction instruction signal from the pulse width control circuit 22 to turn the servo amplifier 28 when rotating the DC motor in the forward direction.
The output signal of the low pass filter 25 is outputted, and when rotating in the opposite direction, the polarity inversion signal from the polarity inversion circuit 27 is outputted. The servo amplifier 28 amplifies the input error signal to drive the DC motor l, and also returns a signal detected by the current detection circuit 29 to the drive current flowing through the windings of the DC motor 1 to the servo amplifier 28 to determine the speed. Control.

The DC motor I is driven by the speed control mode signal output from the pulse width control circuit 22 until it approaches the desired stop position, and just before the stop position, the speed control mode is switched to the damping static mode, the switch circuit 26 is deenergized, and the pulse motor is excited. Activate circuit 30.

In the initial stage, the excitation circuit 30 has a movement amount equal to that of the command circuit 21.
Therefore, the excitation phase to be excited at the final stop position is calculated and held in advance. For this reason,
The pulse motor 5 rotates by one advance angle determined from the relationship between the excitation phase excited by the excitation circuit 30 and the magnetic poles of the rotor, and then stops.

Next, the drive control operation of the motor will be explained below using the control block diagram shown in FIG. 2 and the time chart shown in FIG. 3.

When the movement amount and rotation direction to the next position to be moved are input from the command circuit 21 to the pulse width control circuit 22, the pulse width control circuit 22 adjusts the movement amount as shown in FIG.
) is accessed from the memory circuit 23 and output to the phase comparison circuit 24. Further, the pulse width control circuit 22 outputs the speed control mode signal and rotation direction signal shown in FIG. As the DC motor 1 rotates, the pulse signals output from the transducer 8 are waveform-shaped by the position signal detection circuit 31, and have a phase difference of 90 degrees from each other as shown in FIGS. 3(C) and 3(C)'. position signals A, B with
is output to the rotation direction detection circuit 32. The rotation direction detection circuit 32 detects the rotation direction depending on which of the position signals A and B is detected first, and the pulse width control circuit 22
Figure 3 (C
) The position signal A shown in FIG. 3(B) is phase-compared with the pulse train signal output from the pulse width control circuit 22 shown in FIG. 3(B), and the phase difference signal shown in FIG. 3(D) is filtered through a low-pass filter. Output to 25. low pass filter 2
5 averages the phase difference signal having both positive and negative polarities and calculates the third
A signal with the polarity shown in FIG. 2(E) is output to the servo amplifier 28 through the switch circuit 26. Since the DC motor 1 is supplied with the output signal of the low-pass filter 25.

As shown in FIG. 3(F), the motor is driven to gradually accelerate and gradually decelerate as it approaches the stop position. The pulse width control circuit 22 stores the movement amount input from the command circuit 21 in a counter at an initial stage, but it is sequentially subtracted by the position signal A output from the position signal detection circuit 31 as the DC motor 1 rotates. , detects that the count value is 0, that is, that the pulse motor 5 is in front of the unit walk angle, and switches the speed control mode signal output from the pulse width control circuit 22 shown in FIG. 3(A) to the damping stationary mode signal. , is output to the switch circuit 26 and the excitation circuit 30. As shown in FIGS. 3(G) and ()(), the DC motor 1 stops driving, and the excitation circuit 3° is energized, so the pulse motor 5 starts driving.

The pulse motor 5 rotates one step in advance and then is held stopped in accordance with the static torque characteristic of the motor itself.

FIG. 4 shows a specific configuration of the pulse motor excitation circuit 30. Excitation winding of pulse motor 1. II, IIl,
rV has one end connected in common and is connected to a power source (not shown) via a transistor Tri.

The other ends of the excitation windings are connected to drive transistors Tr2 and T, respectively.
It is connected to r3, Tr4, and Tr5, and when the pulse motor is driven, any excitation winding is excited by the drive signal output from the drive circuit 41. The back electromotive force generated in each excitation winding is configured to be consumed through a feedback loop formed by diodes D1, D2, D3, and D4 and a resistor R.

When the rotation direction and movement amount are input from the command circuit 21, the drive circuit 41 calculates and holds in advance the excitation phase when the damping static mode is entered, and switches from the speed control mode to the damping static mode. The pulse motor is driven.

In the above embodiment, the position signal generating means used to drive the DC motor was explained as a transducer composed of an encoder disk plate, a light emitting element, and a light receiving element. Since the pulse motors that are used in the invention also rotate synchronously, it is possible to extract a position signal using the electromotive force generated in the excitation phase of the pulse motors.This method will be explained below.

An embodiment in which the electromotive force generated in the excitation winding of a pulse motor is used instead of the transducer 8 will be described with reference to FIGS. 5 and 6. Note that the same parts as in FIGS. 2 and 4 are given the same reference numerals, and only the parts that differ in operation will be explained.

In FIG. 5, signals drawn from the connection points between the excitation winding I and the transistor Trl, and between the excitation winding I and the transistor Tr2 are input to the positive input terminals of the differential amplifiers 41 and 42. The collector output signal of Tri is input to the negative input terminals of the differential amplifiers 41 and 42, and the differential output signal is input to the position signal detection circuit 31 composed of Schmitt circuits 44 and 45.

While the speed control mode signal is input to the excitation circuit 30, the excitation phase drive signal is not output from the drive circuit 41, and the transistors T r 2 to T r 5 are turned off, but the servo motor 1 is driven. When the pulse motor 5 rotates, the rotor of the pulse motor 5 rotates together with the rotation of the rotor of the servo motor 1 since the motor shafts are connected to each other. When the rotor of the pulse motor 5 rotates, an electromotive force is generated in the excitation winding, and this signal is input to the operating amplifiers 42 and 43. The output signals of the operating amplifiers 42 and 43 are the position signal output circuit w
The signals are input to a Schmitt circuit 131, and are waveform-shaped and output as position signals A and B. With this configuration, there is no need to provide a special transducer, so
The control block diagram is as shown in FIG.
The configuration is such that a signal is directly input from the position signal detection circuit 31 to the position signal detection circuit 31.

As an embodiment of the present invention, a method for coupling a DC motor and a pulse motor through a joint has been described.
Needless to say, it may be directly connected.

As explained above, according to the present invention, the speed is controlled by the DC motor in the rotation control mode, and the pulse motor is used to control the damping near the target stop position and the static mode, so the advantages of the DC motor are When controlling a certain speed, responsive and efficient control can be performed, and when stopping, a pulse motor in which the rotation angle per drive pulse is uniquely determined can be performed using a simple device.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of the present invention, Fig. 2 is a control block diagram showing an embodiment for carrying out the invention, Fig. 3 is a time chart diagram of Fig. 2, and Fig. 4 is excitation of the pulse motor. A specific configuration diagram of the circuit, FIG. 5 is a specific configuration diagram of a position signal generation circuit using the electromotive force generated in the excitation winding of a pulse motor,
FIG. 6 is a control block diagram when the position signal generation circuit of FIG. 5 is used. Identical parts in each figure are given the same symbols, ■ is a DC motor,
5 is a pulse motor, 21 is a command circuit, 22 is a pulse width control circuit, 23 is a seaweed storage circuit, 24 is a phase comparison circuit, 25 is a low-pass filter, 28 is a servo amplifier, 30 is an excitation circuit, 31 is a position signal detection circuit, 32 is a rotation direction detection circuit. Patent applicant Riko Co., Ltd.-Ctsuha

Claims (1)

[Claims] In a motor positioning control system, a DC control motor that does not have a detent on its own and a DC control motor that has a detent on its own are mechanically or electromagnetically coupled, and does not mainly have the detent force during speed control. A motor drive control system characterized in that the motor is driven by a DC motor, and near a stop position, switching control is performed to the DC control motor having the detent, and positioning control is performed by operating the DC motor having the detent.