JPH07303386A - Controller of sewing machine motor - Google Patents

Abstract

PURPOSE:To provide a controller of a sewing machine motor which can control the sewing machine motor following the fluctuation in a load and which can cope with the change in a pattern of the fluctuation in the load. CONSTITUTION:A rotating speed Vn and a phase Pn of a main shaft 13 are detected by a sensor circuit 14. The data about the phase Pn of the main shaft 13 is quantized by a controller 15 of a one-chip microcomputer 19 and a manipulated variable U corresponding to the quantized phase Kn is read out from a RAM and is output to a driving circuit 16. Then, the manipulated variable U to correspond to a quantized phase Kn-1 is so determined by an adaptor 18 that the speed Vn detected by the sensor circuit 14 may coincide with a desired speed Vd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine motor control device for controlling a sewing machine motor for rotationally driving a main shaft of a sewing machine.

[0002]

2. Description of the Related Art Conventionally, in a control device for a sewing machine motor, feedback control is generally used as shown in FIG. 5 in order to rotate the main shaft of the sewing machine at a constant speed. That is, a sewing machine motor 1 including, for example, a universal motor is connected to a main shaft 2 of a sewing machine by a belt, a gear mechanism, or the like, and by rotating the main shaft 2, a needle bar and a shuttle mechanism are driven. There is. The sensor circuit 3 is composed of an encoder or the like, detects an angular velocity (hereinafter simply referred to as velocity) Vn (discrete time is referred to as n) of the sewing machine motor 1, and further detects an angular acceleration (hereinafter simply referred to as acceleration) from a time series of the velocity Vn. An) is detected.

The proportional controller 4 outputs the manipulated variable Un to the motor drive circuit 5 using the speed Vn and the acceleration An detected by the sensor circuit 3 and the target speed Vd. At this time, the manipulated variable Un is represented by the following equation using constants α and β. Un = Un-1 −α · (Vn−Vd) −β · An (1)

The motor drive circuit 5 converts the manipulated variable Un output from the proportional controller 4 into a physical quantity (for example, a DC voltage) according to the drive system of the sewing machine motor 1 to drive the sewing machine motor 1, and Thus, control is performed so that the speed of the sewing machine motor 1 matches the target speed Vd.

[0005]

However, the above-mentioned general feedback control has a drawback that it is not necessarily suitable for controlling the sewing machine motor 1 due to the circumstances peculiar to the sewing machine. That is, in the sewing machine, the load greatly increases at the moment when the sewing needle pierces the cloth, when the sewing needle penetrates the cloth, when tightening the thread, and the load changes rapidly. Therefore, the control of the sewing machine motor 1 cannot sufficiently follow the load fluctuation.

By the way, since the needle bar of the sewing machine is driven in synchronization with the main shaft 2, there is a correlation between the phase of the main shaft 2 and the position of the needle bar (sewn needle), that is, the position where load variation occurs. Therefore, as shown in Japanese Patent Application Laid-Open No. 60-183993, a control device for a sewing machine has been considered in which attention is paid to the periodicity of the load fluctuation. Although illustration is omitted, in this thing, the fact that the main shaft has come to the phase (load increase section) where the load torque increases is detected by the support plate and the hall sensor attached to the main shaft, and based on the detection, By adding the speed increase adjustment value to the rotation speed command value, it is possible to cope with the load fluctuation.

However, this Japanese Patent Laid-Open No. 60-183993
In the control device for the sewing machine motor disclosed in Japanese Patent Publication No.
Since the load increase section is fixed and the speed increase adjustment value is also fixed, it is effective only when the load fluctuation pattern is constant.For example, the cloth thickness, cloth quality, sewing needle, thread type, etc. may change. However, it was not possible to cope with the change in the pattern of the load fluctuation due to this, and it was not possible to perform sufficiently effective control.

The present invention has been made in view of the above circumstances, and an object thereof is to be able to sufficiently control a sewing machine motor to follow a load change and to sufficiently perform a change in a load change pattern. It is to provide a control device of a sewing machine motor which can deal with it.

[0009]

A control device for a sewing machine motor according to a first aspect of the present invention controls a sewing machine motor that rotationally drives a main shaft of a sewing machine, and outputs an operation amount to the sewing machine motor. Control means, detecting means for detecting the state quantity of the spindle, and comparing the state quantity detected by this detecting means with a target value to adjust the manipulated variable so that the state quantity matches the target value. It is characterized in that it is provided with an adapting means.

In this case, a storage means for storing operation amounts respectively corresponding to a plurality of phases of the spindle is provided, and the control means is
The operation amount stored in the storage unit is output in accordance with the phase of the spindle detected by the detection unit, and the adaptation unit is configured to shift the state amount detected by the detection unit from a target value. The operation amount for the delayed phase stored in the storage means may be sequentially updated based on the amount (the invention of claim 2).

Further, the detecting means includes an encoder connected to the main shaft, and each phase corresponding to the manipulated variable stored in the storage means is output from the encoder by one rotation of the main shaft. It is effective if the entire circumference of the main shaft is divided by a divisor of the number (invention of claim 3).

[0012]

According to the sewing machine motor control apparatus of the first aspect of the present invention, the control means outputs the operation amount to the sewing machine motor, and the detecting means detects the state quantity of the spindle. By the adapting means, the operation amount is adjusted so that the state quantity detected by the detecting means matches the target value. Therefore, it is possible to perform the control adapted to the load fluctuation and the change of the load fluctuation pattern.

According to the sewing machine motor control device of the present invention, the control means outputs the operation amount corresponding to each phase of the spindle stored in the storage means in accordance with the phase of the spindle detected by the detection means. To be done. Therefore, it is possible to output the operation amount according to the correlation between the phase of the main shaft and the load fluctuation. Then, the operation amount for the delayed phase stored in the storage unit is sequentially updated by the adaptation unit based on the amount of deviation between the state amount detected by the detection unit and the target value. The operation amount corresponding to the load fluctuation and the change in the load fluctuation pattern is always stored.

According to the sewing machine motor control device of the third aspect, each phase corresponding to the manipulated variable stored in the storage means is:
Since it is divided by the divisor of the number of pulses output from the encoder for one rotation of the spindle, the control means outputs the manipulated variable based on the phase of the spindle detected by the encoder connected to the spindle. It can be performed reliably and with high accuracy.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a schematic configuration of a control device 11 for a sewing machine motor according to this embodiment. Here, for example, a sewing machine motor 1 including a universal motor
Reference numeral 2 is directly or directly connected to the main shaft 13 of the sewing machine via a belt, a gear mechanism or the like, and by rotating the main shaft 13, the needle bar and the shuttle mechanism are driven.

Then, the control device 11 controls the spindle 1
Sensor circuit 1 as a detection means for detecting the state quantity of 3
4, controller 15 as control means, the sewing machine motor 1
A driving circuit 16 for driving the driving circuit 2, a delay element 17 as a delay means, and an adaptor 18 as an adapting means. Although not shown in detail, the sensor circuit 14 is configured to include a rotary encoder, and in this case, the speed Vn (rpm) as the state quantity of the spindle 13 is set.
And the phase Pn (degrees) are detected. still,
The discrete time is n.

In the present embodiment, the controller 15,
The delay element 17 and the adaptor 18 are the one-chip microcomputer 1
9 and its function is realized by its hardware and software configuration.
As shown in FIG. 2, the one-chip microcomputer 19 includes a CPU 20 that performs various arithmetic processes, a ROM 21 that stores a processing program, a RAM 22 that functions as a storage unit as described later, a timer 23 that generates an interrupt process,
It is composed of an I / O port 24 and the like for exchanging data with the outside.

The RAM 22 is provided with a manipulated variable storage area 22a, in which a manipulated variable U (K = K = corresponding to a plurality of phases Kn quantized at constant angular intervals of the spindle 13).
Kn) is being remembered. In this case, the phase K
n is 0 to 224 obtained by quantizing the entire circumference (360 degrees) of the main shaft 13 by dividing it by a divisor of the number of pulses output from the sensor circuit 14 (rotary encoder) during one rotation of the main shaft 13, for example, 225. Is an integer up to.

Therefore, this phase Kn is expressed by the following equation: Kn = 225 × Pn / 360 (2) (0≤Kn≤224). The RAM 22 is also provided with a phase storage area 22b for storing the phase.

As shown in FIG. 1, the controller 15 receives the data of the phase Pn of the main shaft 13 from the sensor circuit 14, quantizes it by the above equation (2), and quantizes the phase Kn. The operation amount U (K = Kn) corresponding to is read from the RAM 22 and output to the drive circuit 16. The drive circuit 16 converts the manipulated variable U (K = Kn) into a physical quantity suitable for the drive system of the sewing machine motor 12, and drives the sewing machine motor 12. In this embodiment,
For example, a DC voltage is output.

On the other hand, the delay element 17 delays the phase Pn detected by the sensor circuit 14 as Pn → Pn-1 (3).

Then, the adaptation unit 18 includes a delay element 17
The phase Pn-1 delayed by the above is quantized by the above equation (2), and the manipulated variable U (K =
Kn-1). The adaptor 18 sequentially updates the manipulated variable U (K = Kn-1) by the following equation based on the speed Vn detected by the sensor circuit 14 and the target speed Vd, and writes it in the RAM 22. ing. U (K = Kn-1) ← U (K = Kn-1) -2 · μ · (Vn-Vd) (4) However, μ is a small positive constant.

Next, the operation of the above configuration will be described with reference to FIGS. The flowcharts of FIGS. 3 and 4 show the main part of the operation procedure of the CPU 20 of the one-chip microcomputer 19. When the processing program is started, as shown in FIG. 3, first, in step S1, RA
The manipulated variable U (K = 0, ..., 244), phase and the like stored in M22 are initialized. Therefore, at this point, the manipulated variables U (K = 0, ..., 244) for all the phases Kn are set to zero. In the next step S2, driving of the timer 23 is started. With this, a fixed time interval (for example, 8.3 mse
A timer interrupt is generated every c). This timer interruption is continued until the operation of the sewing machine ends, for example, the switch is turned off (step S3).

When a timer interrupt occurs, the CP
U20 executes an interrupt handler as shown in FIG. That is, in step S11, the previous phase Pn-1 written in the phase storage area 22b of the RAM 22 in the previous interrupt processing is read. However, in the first interrupt processing, the value is the value initialized in step S1.

Next, in step S12, step S1
The phase Pn-1 read in 1 is quantized by the above equation (2) to obtain the quantized phase Kn-1. Then, the manipulated variable U (K = Kn corresponding to the quantized phase Kn-1)
-1) is the current speed V detected by the sensor circuit 14.
Using n and the target speed Vd, the process (4) is performed to update the manipulated variable U (K = Kn-1) and write it in the RAM 22.

Subsequently, in step S13, the CPU 20
Quantizes the current phase Pn detected by the sensor circuit 14 by the equation (2), reads the manipulated variable U (K = Kn) corresponding to the quantized phase Kn from the RAM 22 and outputs it to the drive circuit 16. To do. Also, along with this, the current phase P
n is written in the phase storage area 22b of the RAM 22, and the interrupt processing is completed.

As described above, this interrupt process is repeated at predetermined time intervals. At this time, in the initial state of control start, the operation amount U (K = 0,
, 244) are all initialized, the optimum manipulated variable is not achieved and the velocity deviation (Vn-Vd) is also large. However, in step S12, the spindle 1
The manipulated variable U (K = 0, ..., 244) corresponding to each phase Kn of 3 is
It will be gradually updated toward the optimum value. Then, as the update is repeated, the manipulated variable U (K = 0, ..., 244) approaches the optimum value, so the velocity deviation also gradually decreases, and finally, the manipulated variable U (K = K = 0,…, 244) will be converged to the optimum value.

Here, in the sewing machine, the load is greatly increased at the moment when the sewing needle pierces the cloth, the moment when the sewing needle penetrates the cloth, the moment when the thread is tightened, and further, the load fluctuation occurs rapidly. . Further, although there is a correlation between the phase of the main shaft 13 and the position of the needle bar (sewing needle), and thus the position where load variation occurs, for example, as the cloth thickness, cloth quality, sewing needle, thread type, etc. change. The pattern of the load fluctuation (the phase of the spindle 13 in which the load fluctuation occurs, the size thereof, etc.) also changes.

However, in the control device 11 of the present embodiment, first, the manipulated variable U (K = 0, K = 0, corresponding to the phase Pn of the spindle 13 and thus the phase Kn detected by the sensor circuit 14).
, 244), the sewing machine motor 12 is controlled. Therefore, unlike the case where the feedback control is performed, the sewing machine motor 12 is controlled without being delayed by the load fluctuation even if the load fluctuation is sudden. be able to.

The manipulated variable U corresponding to each phase Kn
The control is performed while sequentially updating (K = 0, ..., 244) according to the detected speed deviation, so that even when the load fluctuation pattern changes, the operation amount U (K = 0, ... , 244)
Is converged to the optimum value, and adaptive control is performed.

As described above, according to the sewing machine motor control device 11 of the present embodiment, unlike the conventional device, the sewing machine motor 12 can be controlled sufficiently following the load fluctuation.
Moreover, it is possible to obtain an excellent practical effect that it is possible to sufficiently cope with the case where the load fluctuation pattern changes. In particular, in this embodiment, one rotation of the main shaft 13 is divided into 225 phases and the operation amount U (K =
Since 0, ..., 244) is set, fine and precise control can be performed. Further, in the present embodiment, the one-chip microcomputer 19 functions as each unit, so that it is possible to obtain advantages such as a simple structure.

In the above embodiment, the interrupt processing is performed by the timer 23 at a predetermined time interval. However, for example, it is synchronized with the detection of the pulse output by the rotary encoder constituting the sensor circuit 14 (main shaft rotation 13). Alternatively, it may be configured to be performed. Further, the sensor circuit is not limited to one using a rotary encoder, but may be one using a magnetic sensor or the like. Furthermore, the control means, the adapting means, and the delay means are not limited to those using a one-chip microcomputer, but can be configured by independent circuits.

In addition, the present invention is not limited to the above-described embodiments, and for example, the driving system of the sewing machine motor 12 is not limited to the DC voltage driving system, but may be the AC voltage driving system or the pulse width modulation driving system. It can be implemented by appropriately changing it within a range not departing from the gist of the present invention.

[0034]

As is apparent from the above description, the present invention has the following excellent effects. That is, according to the sewing machine motor drive device of claim 1, the control means for outputting the operation amount to the sewing machine motor, the detecting means for detecting the state amount of the spindle, and the state amount detected by the detecting means are provided. The sewing machine motor can be controlled by sufficiently following the load change, since the adjusting means is provided so as to compare the state quantity with the target value and adjust the manipulated variable so as to match the state quantity with the target value. Even when the load fluctuation pattern changes, it is possible to sufficiently cope with it.

In this case, a storage means for storing operation amounts respectively corresponding to a plurality of main shaft phases is provided, and the control means is
The operation amount stored in the storage unit is output in accordance with the phase of the spindle detected by the detection unit, and the adaptation unit is configured to shift the state amount detected by the detection unit from a target value. If the operation amount for the delayed phase stored in the storage means is sequentially updated on the basis of the amount (the sewing machine motor drive device according to claim 2), the correlation between the phase of the spindle and the load fluctuation is obtained. It is possible to output the operation amount according to the relationship, and it is possible to effectively respond to the change in the load fluctuation pattern.

Further, the detecting means includes an encoder connected to the main shaft, and each phase corresponding to the manipulated variable stored in the storage means is output from the encoder by one rotation of the main shaft. If the entire circumference of the main shaft is divided by a divisor of the number (drive device of the sewing machine motor according to claim 3), fine and highly precise control can be performed.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention and showing an overall configuration of a control device.

FIG. 2 is a block diagram showing the configuration of a one-chip microcomputer.

FIG. 3 is a flowchart showing the operation of the CPU.

FIG. 4 is a flowchart showing an interrupt handler.

FIG. 5 is a diagram corresponding to FIG.

[Explanation of symbols]

In the drawings, 11 is a control device, 12 is a sewing machine motor, 13 is a spindle, 14 is a sensor circuit (detection means), 15 is a controller (control means), 16 is a drive circuit, 17 is a delay element, 18
Is an adaptor (adaptive means), 19 is a one-chip microcomputer, 2
Reference numeral 0 is a CPU, 22 is a RAM (storage means), and 23 is a timer.

Claims (3)

[Claims] 1. A control means for controlling a sewing machine motor for rotationally driving a main shaft of a sewing machine, the control means outputting an operation amount to the sewing machine motor, and a detection means for detecting a state quantity of the main shaft. A control device for a sewing machine motor, comprising: an adapting means for comparing the state quantity detected by the detecting means with a target value and adjusting the manipulated variable so that the state quantity matches the target value. 2. An operation amount stored in the storage means according to the phase of the spindle detected by the detection means, the storage means storing an operation amount corresponding to each of a plurality of phases of the spindle. And the adaptive means sequentially updates the operation amount for the delayed phase stored in the storage means based on the amount of deviation between the state amount detected by the detection means and the target value. The sewing machine motor control device according to claim 1, wherein the control device is configured. 3. The detection means includes an encoder connected to the main shaft, and each phase corresponding to the manipulated variable stored in the storage means is the number of pulses output from the encoder by one rotation of the main shaft. 3. The entire circumference of the main shaft is divided by a divisor of 2.
A control device for the sewing machine motor described.