JPS63107499A - Controller for stepping motor - Google Patents

Abstract

PURPOSE:To suppress a vibration at the time of stopping a stepping motor thereby to accurately position the motor by repeating normal and reverse rotations predetermined times after a final pulse is delivered. CONSTITUTION:Rear pulse train data generating means 2 produced the final step pulse of pulses for driving a stepping motor, and then generates pulse train data to be delivered. Switching means 6a reads out, upon inputting final pulse discriminating means 6, rear pulse train data, and alternately outputs a switching signal for switching a pulse direction to normal or reverse to a stepping motor drive circuit 7 synchronously with the rear pulse train data. Thus, the vibration of the motor is attenuated during the inputting period of the pulse signal which varies in normal and reverse directions.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for a stepping motor, and more particularly to a control device that improves vibration-free settling of a stepping motor after sending a feed pulse.

[Prior Art] Generally, when controlling the drive of a stepping motor, a pulse signal with a frequency corresponding to the number of rotations and rotational speed of the stepping motor is output from a pulse generator equally divided into rotation number groups to a drive control unit, and drive control is performed. Let's do it.

A typical control device for this is shown in Fig. 5. In Fig. 0, (1) controls the drive pulse for driving the stepping motor and the rotation direction as shown in Fig. 6 based on an external rotation command. A control circuit that outputs commanded direction pulses by a microcomputer (hereinafter abbreviated as microcomputer) (la), and (7) a stepping motor drive circuit that inputs a drive control output to the stepping motor (8) based on each of the above-mentioned pulses. and a stepping motor (
Under the drive control of 8), the load (10) of the mechanism part engaged by the coupling (9) is driven.

When the stepping motor (8) is used to move the load (10) for a certain period of time or a certain distance at a constant speed, as shown in Fig. The amount of movement (for example, 10 pulses) of 1O) is output from the control circuit (1) to the stepping motor drive circuit (7). As a result, the load (10) moves at a constant speed by the amount of the sending pulse.

Conventionally, as a method for generating pulse signals of a pattern according to the operating state of the stepping motor (8) as described above, each bit information constituting the pulse train for each pulse pattern is stored in individual memory addresses, and There is a method in which each pulse pattern is stored in each address space, and then the memory is accessed and pulse data is output.

Next, the operation procedure for accessing the memory table and outputting pulse data will be explained with reference to the flowchart shown in FIG. 7(a).

The pulse output calculation section of the microcomputer (1a) calculates the number of pulses n,
and read the rotation direction command, etc. (2-1). Next, based on these rotation commands, the pulse pattern is determined, the start address (TA+o) in the memory table (see Figure 8) where the pulse pattern is stored is calculated, the direction of one rotation is determined, and the direction pulse The stepping motor drive circuit (
7) Output to (2-2) to (2-4) After determining the start address (TA+o), the contents of address (TA+o) are temporarily sent to the 7-cumulator ACC in the microcontroller (la) for data transfer operation. When moving (2-5), the microcomputer (1a) detects the data contents of the accumulator ACC and determines whether it is ゛80'' indicating the final data (2-8), and if it is ``80'', Stop the pulse output.If it is not "80", judge whether it is "l" or not.2-
7) If it is "1", turn on the rising pulse as shown in Figure 1 (b) (2-8), and after the pulse width has been determined, turn off the pulse output (
2-9), (2-10).

After turning off the pulse output, increment the memory address by one and update the read address (see 2-11).
), microcontroller (la) (update address (TAI) in II
Ool), and if it is not 480″, (TA
It is determined whether +o, +)≠1 (2-6).

(2-7) As a result of this determination, if (TA+o,+)≠1, the pulse output is turned off (2-12). After the pulse output is turned off, if time T11 has elapsed, update the memory address to (TA1012) (2-12), (
2-13), (2-11), and as long as the content of the memory address (TAn) updated every T buttock time is (TAn)≠1, the pulse output is turned off (2-12), and (2-12), An) ml is determined in step (2-7), a pulse with a pulse width Tw is output again in steps (2-8) to (2-10).

When "1" and "O" are read from each memory address as described above, pulse train data is generated having a pulse period determined by the access time of the memory address where "O" is stored. The number of pulses at the time is determined by the number of memory addresses storing "1".

[Problems to be Solved by the Invention] Conventional stepping motor control devices determine the motor rotation speed or rotation angle based on the number of feed pulses sent to the stepping motor drive circuit, and connect the motor to the motor shaft. The load is moved to a position determined by the number of pulses and then stopped, but when the stepping motor is started and stopped, vibrations occur due to the relationship with the stepping motor when stopping, and due to the vibrations, the load does not stop at a predetermined position. There was a problem in that the phenomenon of tax adjustment stopping at certain positions could occur.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a control device for a stepping motor that suppresses vibrations when stopped and can perform accurate positioning.

[Means for solving the problem] Control of the stepping motor according to the present invention? After sending out a pulse output that determines the moving direction and moving position of the stepping motor driving load from the pulse output stage f, the pulse train data generation means generates the number of pulses and the number of pulses corresponding to the number of pulses per unit time of the pulse output. New pulse train data having a pulse frequency is generated, and each pulse signal based on the pulse train data is sent to the stepping motor drive circuit together with a pulse direction switching signal.

[Function] According to the stepping motor control device according to the present invention, after the final step pulse in the first output pulse train data is determined, the newly output pulse signal of a specific frequency is used as the ``pulse direction switching signal''. is also sent to the stepping motor drive circuit, so that the vibrations of the stepping motor are damped during the input period of the pulse signal varying in the forward and reverse directions.

[Embodiment] FIG. 1 is an overall configuration diagram showing an embodiment of a stepping motor control device of the present invention. (2) is a late pulse train data generation means that generates pulse train data to be sent out after sending out the final step pulse of the stepping motor drive pulse; (3) is a Noculus train data storage means;
commands the storage means (3) to read pulse train data. <A pulse train data reading means; (5) is a pulse output means for outputting a motor drive pulse output to the stepping motor drive circuit (7) based on the read pulse train data; (6) is a pulse output means for outputting a final step pulse from the read pulse train data; Final nox determination means for determining, (6a
) commands the pulse train data reading means to read out the late pulse train data in accordance with the input of the final pulse determination signal, and also instructs the stepping motor drive circuit ( 7) is a pulse direction switching stage f which alternately outputs a switching signal for switching the pulse direction between forward and reverse.

The overall configuration diagram of the stepping motor control device used in the embodiment of FIG. 1 is the same as that of FIG. 5, and detailed explanation will be omitted.

Next, the operation of the above embodiment is shown in FIGS. 2(a), (b) and 3.
This will be explained with reference to FIGS. 4(a) and 4(b). Second
Figure (a) is a flowchart showing the pulse output program stored in the memory of the microcomputer (la), and Figure 2 (b)
is a pattern diagram of a pulse train output by executing this program, Figure 3 is a pulse pattern diagram showing the relationship between directional pulses and drive pulses, and Figure 4 (a) is a diagram showing the pulse train data of n pulses stored. FIG. 4B is an explanatory diagram of a memory table showing the contents of addresses in the storage device. FIG. 4B is an explanatory diagram of a memory table in which the number of pulses of the second pulse train data is stored as a table.

Steps (2-1) to (2-13) of the flowchart described in E.
) shows the f order for generating the first pulse train data shown in FIG. 3, and since this flowchart is the same as the flowchart in the conventional device, detailed explanation will be omitted.

The pulse output calculation section of the microcomputer (la) reads rotation commands such as pulses and rotation direction commands (2-1).

Based on these rotation commands, the pulse patterns of the first pulse train and the second pulse train are determined, and the first pulse train data and the second pulse train data are determined.
Calculating the top address where the pulse train data is stored and determining the rotation direction of the stepping motor based on the first pulse train data (2-2), (2-3),
After the first pulse train data is set, the number m of output pulses is determined from the second pulse train table (see Figure 4 (b)) (2-14), and then the pulse frequency constant m is determined from the second pulse train table. (2-15).

The first pulse train data is determined as described above, and the following steps (2-4) to (2-13) are carried out to read out the first pulse train data shown in FIG.
1ft) and executes the second pulse train table generation routine.

First, in step (2-18), step (2-14)
Determine whether or not the pulse signal has been output for the number of pulses determined in , and if YES, the second pulse generation routine is terminated as all the second pulse trains have been output (2-28).
, and if step (2-113) is NO, the determined number of pulses is subtracted by one (2-17). n after the final first pulse train is output, that is, nml/f2
2-18) If it is determined that the frequency of the second pulse train has elapsed, the direction pulse and the drive pulse ('a) are used to drive the stepping motor as shown in Figure 3. Output to circuit (7) and rotate stepping motor (8) in the opposite direction by one pulse (2-19)
, (2-20). After outputting the above drive pulse (a), T
Determine whether or not W time has elapsed (2-21), and if it has elapsed, turn off the drive pulse output (2-22)
, After the Hals output is turned off, it is determined whether or not n, which determines the period of the second pulse train, has elapsed (2-23), and after n elapses, the positive direction pulse and drive pulse (b) are sent to the stepping motor drive circuit (7). output and return the stepping motor (8) in the forward direction by one pulse (2-24).

(2-25) After one hour has elapsed, the drive pulseless output is turned off (2-27).
-17) to (2-27) in step (2-18) m =
It repeats until it is determined that the rotation is o, and alternately outputs rotation forward direction pulses and rotation reverse direction pulses to the stepping motor drive circuit (7) every n cycles. In Fig. 3, there are three forward pulses and three reverse pulses, and the pulse frequency is f2.
is constant, but may be changed depending on the frequency and number of pulses of the first pulse train.

[Effects of the Invention] As described above, according to the present invention, after sending out a stepping motor driving pulse signal, a predetermined number of motor forward rotation and reverse rotation pulses are applied at a pulse period corresponding to the frequency and number of pulses of the stepping motor drive pulse signal. Since it is equipped with a means to repeatedly output, even if the stepping motor resonates with the pulse signal frequency when the stepping motor is stopped, the resonant vibration is suppressed during the generation period of the motor's forward and reverse rotation pulses of a constant frequency, so the stepping motor This has the effect of accurately positioning the load without making any missteps.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an embodiment of the stepping motor control device of the present invention, FIG. 2(a) is a flowchart explaining pulse output operation by a microcomputer,
b) is a pulse pattern diagram of pulse train data output by executing the pulse output program, Figure 3 is a pulse pattern diagram showing the relationship between rotational directional pulses and drive pulses, and Figure 4 (a) is a pulse train of lin pulse. Figure 4 (b) is a memory table diagram that stores the data; Figure 4 (b) is a memory table diagram that stores the second pulse train data; Figure 5 is a system configuration diagram of the stepping motor control device; Figure 6 is the direction in the first pulse train data. FIG. 7(a) is a pulse pattern diagram showing the relationship between sexual pulse and drive/<response, and FIG. 7(a) is a flowchart explaining the conventional pulse output operation.
b) is a pattern diagram of pulse train data generated by the pulse output operation, and FIG. 8 is a memory table diagram in which the pulse train data is stored. In the figure, (1) is a control circuit. (2) is a latter stage pulse train data generation means, (3) is a pulse train data storage valve stage, (4) is a pulse train data reading means, (5) is a pulse output means, (8) is a final pulse judgment means, (6a) is Pulse direction switching means, (7) is a stepping motor drive circuit, and (8) is a stepping motor. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] Pulse train data of a predetermined frequency generated according to the operating state of the stepping motor is outputted from a pulse control circuit, and an excitation current outputted from a drive circuit based on the pulse train data is inputted to the stepping motor to perform motor drive control. In a stepping motor control device for controlling a stepping motor, a second stage pulse train data generating means sets the number of pulses and the pulse frequency of the pulse train signal to be output after outputting the final step pulse based on the number of pulses of the pulse train signal, and generates new pulse train data; a data storage means; a pulse train data reading means for reading pulse train data from the storage means; a pulse output means for outputting a motor drive pulse output to a stepping motor drive circuit based on the read pulse train data; and a final step pulse from the read pulse train data. A final pulse determining means for determining the final pulse train, and upon input of the final pulse determining signal, commands the pulse train data reading means to read the latter half pulse train data, and in synchronization with the reading of the latter half pulse train data, the stepping motor drive circuit. 1. A control device for a stepping motor, comprising pulse direction switching means for alternately outputting a switching signal for switching the pulse direction between forward and reverse directions.