JPH0638596A - Pulse motor drive control device and method in sewing machine - Google Patents

Abstract

(57) [Abstract] [Purpose] To enable the pulse motor used in the drive mechanism of the sewing machine to operate at high speed and high torque as much as possible. [Composition] The command pulse speed is controlled to be increased using as parameters the increase / decrease fluctuation tendency of the load of the pulse motor and the delay or advance state of the actual motor position with respect to the current command position. For example, when the delay of the actual motor rotation position with respect to the current command position is the delay amount that produces the maximum torque,
When the load tends to increase, the speed is not accelerated, and when the load tends to decrease, the speed is increased. As a result, the acceleration control can be efficiently performed according to the load increase / decrease fluctuation tendency, and high-speed operation becomes possible. Also, if the deviation between the commanded position and the actual position is controlled so as to increase the speed increasing rate as it becomes smaller than the predetermined positional deviation that causes the maximum torque, it is possible to control so that the delay close to the delay that always causes the maximum torque is directed. High torque operation and high speed operation are possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse motor drive control device used in a drive mechanism for driving an M axis (decorative thread winding axis) in a lockstitch handle embroidery machine and other various sewing machine elements. The present invention relates to a method and a method, and more particularly, to achieving high speed in drive control of a pulse motor, which has been conventionally difficult to drive at high speed such as the M-axis driving pulse motor.

[0002]

2. Description of the Related Art Since the M-axis of an embroidery machine has a heavy load and requires a large torque to drive it, it is difficult to operate at high speed, which is one of the factors that hinder the improvement of embroidery production efficiency. The conventional drive control method for the M-axis pulse motor of the embroidery machine is a complete open loop method, and a command pulse train having a predetermined speed pattern is given to the driver circuit to drive the pulse motor. Therefore, the maximum speed of the command pulse train has to be limited to a speed that assumes a maximum load, and it is inevitably driven at a low speed. In addition, since the M-axis mechanism of the embroidery machine has a complicated structure, mechanical rattling is likely to occur, and a large load fluctuation may occur with it. Sometimes it was a defective product. Not only the M-axis, but also other sewing machine element drive mechanisms are susceptible to delicate rattling, so there are similar problems.

In view of this point, the conventional control method for preventing step-out of the pulse motor has been to apparently delay the speed of the command pulse. That is, if a position detector is attached to the rotary shaft of the pulse motor to detect the actual rotational position of the pulse motor and the delay of the actual rotational position with respect to the current command position exceeds the specified angle, the internal position of the driver circuit The command pulse is appropriately delayed, and drive control is performed as if the command pulse was delayed, whereby the motor drive speed is appropriately delayed to prevent step-out.

[0004]

However, although the conventional control method as described above is effective in preventing step-out, it slows down the motor drive speed, and is the exact opposite of the speed-up of the pulse motor. Technology. Therefore, high-speed operation of the embroidery machine and other sewing machines cannot be realized.
The present invention has been made in view of the above points, and even when a relatively high load or a large load fluctuation or a rattling of a mechanical system is relatively large, such as a drive mechanism of an M-axis of an embroidery machine or other sewing machines. SUMMARY OF THE INVENTION An object of the present invention is to provide a pulse motor drive control device and method for a sewing machine capable of performing high speed operation.

[0005]

A pulse motor drive control device in a sewing machine according to the present invention includes a command pulse generating means for generating a command pulse train corresponding to a command position in a predetermined speed pattern, and a pulse motor according to the command pulse train. In a device including a driving means for driving,
Position detection means for detecting the rotational position of the pulse motor, and for detecting whether the relative load of the motor rotation shaft with respect to the driving force of the pulse motor tends to increase or decrease. In response to the output of the load change tendency detection means, the position detection means and the load change tendency detection means, the load increase / decrease change tendency and the delay or advance state of the actual position with respect to the current command position are used as parameters. A pulse speed adjusting means for generating speed adjustment data for increasing the pulse generating speed of the command pulse train, and controlling the pulse generating speed of the command pulse train generated from the command pulse generating means by the speed adjusting data. It is characterized by doing so.

As an example, the load fluctuation tendency detecting means includes a calculating means for obtaining a difference between a current command position instructed by the command pulse generating means and an actual position detected by the position detecting means, and with the passage of time. The determination means may be configured to determine an increase / decrease tendency of the load applied to the rotating shaft of the pulse motor based on the change in the difference. The configuration is not limited to this, and any other suitable configuration may be used as long as the load variation tendency can be detected.

Further, the pulse motor drive control method in the sewing machine according to the present invention comprises a first step of generating a command pulse train for driving the pulse motor, and a second step of detecting the rotational position of the pulse motor. A third step of detecting a deviation between the current command position and the actual rotation position indicated by the command pulse, and a predetermined position deviation between the current command position and the actual rotation position when the maximum torque is generated are detected. As a reference, a fourth step of performing control to increase the drive speed of the pulse motor so that the speed increase rate is increased as the deviation detected in the third step becomes smaller than the predetermined positional deviation. Is. Further, when the load applied to the pulse motor tends to relatively decrease, the speed increase control is performed so as to increase the speed increase rate even if the deviation detected in the third step corresponds to the predetermined positional deviation. The method may further include a fifth step of performing Further, when the load applied to the pulse motor tends to relatively decrease, a sixth step of performing speed increasing control at a predetermined maximum speed increasing rate may be further included.

[0008]

According to the pulse motor drive control device of the present invention, the command pulse train is defined by using the relative increase / decrease fluctuation tendency of the load of the pulse motor and the delay or advance state of the actual motor rotation position with respect to the current command position as parameters. The speed adjustment data for increasing the pulse generation speed of is generated. With this speed adjustment data, the pulse generation speed of the command pulse train generated from the command pulse generation means is controlled to be increased. That is, control is performed to increase / decrease the pulse generation speed of the command pulse train using the load increase / decrease fluctuation tendency and the delay or advance state of the actual motor rotation position with respect to the current command position as parameters. become.

By adding a change tendency of the load relative to the motor driving force (command value) to the parameter,
Different acceleration control can be performed depending on whether the relative load is increasing or decreasing.
For example, when the delay of the actual motor rotational position with respect to the current command position is the amount of delay that produces the maximum torque, if the relative load tends to increase, speed-up control is not performed, while on the other hand, it tends to decrease. In that case, control can be performed so as to perform speed-up control. That is, even if the degree of delay of the actual motor rotational position with respect to the current command position is the same, different speed increasing control is performed according to the relative load increasing / decreasing tendency at that time. As a result, the speed-up control can be efficiently performed, and the pulse motor can be operated at high speed.

For example, when the delay of the actual motor rotational position with respect to the current command position is the delay amount that produces the maximum torque, if the load tends to decrease, this delay amount decreases unless the motor drive speed is changed. Since it means that there is a tendency, even if the speed is increased, there is no fear of step out, in other words, there is room for speed increase. In such a case, if the speed is increased, the motor drive speed can be efficiently increased without causing step-out. Moreover, due to such speed-up control, the command position is advanced, so that a delay occurs in the actual motor rotational position with respect to the command position, and it is possible to maintain a delay close to the delay that produces the maximum torque. That is, high torque operation can be maintained.

On the other hand, similarly to the above, when the delay of the actual motor rotational position with respect to the current command position is the amount of delay that produces the maximum torque, if the load tends to increase, the speed increase causes a further delay. This means that there is a risk of step out. Therefore, in such a case, the speed is not increased. As a result, high torque operation can be maintained without causing step out.
As one of the embodiments in that case, when the delay of the actual motor rotation position with respect to the current command position is the delay amount that produces the maximum torque, if the load fluctuation is 0 or the increasing tendency, the speed increase rate is set to 0, and the maximum A delay that produces torque may be maintained. Further, as another embodiment, when the delay of the actual motor rotation position with respect to the current command position is the delay amount that produces the maximum torque, if the load change is 0, the speed increase rate is set to 0 and there is an increasing tendency. For example, an appropriate negative acceleration (that is, deceleration) may be performed.

As one embodiment, when the deviation of the actual position from the current command position is within a predetermined range, the pulse speed adjusting means may generate a plurality of stages of speed adjustment data according to the deviation. . Further, with reference to the state where the deviation of the actual position with respect to the current command position gives the maximum torque, the speed adjustment data is generated so that the speed increasing rate is gradually increased as the deviation becomes smaller. You may As a result, a delay tends to occur as the speed increase rate increases, and thus a larger delay occurs due to the speed increase as the position shift becomes smaller, and in any case, a delay close to the delay that always produces the maximum torque is maintained. Will be able to control. Therefore, it is possible to operate as fast as possible while maintaining high torque operation.

According to the pulse motor drive control method of the present invention, the pulse motor is increased so that the speed increase rate is increased as the deviation between the current command position and the actual rotational position becomes smaller than the predetermined position deviation that produces the maximum torque. The control is performed to increase the drive speed of. As described above, there is a tendency for a delay to occur as the speed increase rate increases.Therefore, a smaller delay causes a larger delay due to the speed increase. Will be able to control to maintain. Therefore, it is possible to operate as fast as possible while maintaining high torque operation. Further, when the load applied to the pulse motor tends to relatively decrease, the speed increase control is performed so as to increase the speed increase rate even if the deviation detected in the third step corresponds to the predetermined positional deviation. If you do
After confirming that there is no possibility of step-out due to the relative decrease tendency of the load, it is possible to proceed with the positive speed-up control, and it is possible to further speed up the operation. Further, when the load applied to the pulse motor tends to be relatively reduced, the speedup control can be performed at a predetermined maximum speedup rate, so that even higher speed operation becomes possible.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. 1 is an overall block diagram of a control system showing an embodiment of an embroidery sewing machine to which the present invention is applied. The controller 1 controls the entire operation of this embroidery machine, and is composed of a microcomputer including a CPU 2, a ROM 3, a RAM 4, and the like. The operation panel 5 includes various operation switches for controlling the operation of the embroidery sewing machine, various switches for setting and controlling the embroidery pattern, and the like. The tape reader 6 is for reading the embroidery pattern data from a paper tape on which the embroidery pattern data is recorded. The sewing machine spindle motor 7 is a motor that drives the sewing machine spindle. The rotary encoder 8 for detecting the rotation of the main shaft of the sewing machine detects the rotation angle of the main shaft of the sewing machine. These peripheral input / output devices 5, 6, 7 and 8 are connected to the microcomputer of the controller 1 via the interfaces 9 to 12.

As is well known, the embroidery pattern data is composed of sewing width data of many stitches for realizing a desired embroidery pattern, and the sewing width data for each stitch is X of the embroidery frame 15.
It is composed of a component for instructing an axial movement amount and a component for instructing a Y-axis movement amount, and is supplied from the controller 1 to the XY pulse motor driver circuit 14 via the interface 13. Embroidery frame 1 according to the sewing width data that indicates the X-axis movement amount
The pulse motor 16 for driving the X axis of No. 5 is rotationally driven, and the pulse motor 17 for driving the Y axis of the embroidery frame 15 is rotationally driven according to the sewing width data indicating the Y axis movement amount. As is well known, the needle bar drive mechanism in the sewing machine head is driven according to the rotation of the main shaft motor 7, and the x-axis and y-axis pulse motors 16, 16 are operated during one sewing operation of the needle bar.
In accordance with the rotation of 17, the embroidery frame 15 is moved by xy by one stitch width, and thus one stitch having a desired stitch width is realized.

The M-axis pulse motor 18 is a pulse motor for driving the M-axis (decorative yarn winding axis) of the sewing machine. The M-axis detection rotary encoder 19 detects the rotational position of the rotation shaft of the M-axis pulse motor 18, and is, for example, an incremental pulse generation type rotary encoder. In this embodiment, the present invention is applied to drive and control the M-axis pulse motor 18.

A command pulse train for driving the M-axis pulse motor 18 is sent from the controller 1 to the interface 20.
Given through. This command pulse train is given to the M-axis pulse motor driver circuit 21, and the M-axis pulse motor 18 is driven in response to this. As is well known, the command pulse train for driving the pulse motor 18 is generated in a predetermined speed pattern according to an arbitrary target position, a set speed Vs, and an arbitrary acceleration / deceleration characteristic. FIG. 2 shows an example of a known speed pattern of such a command pulse train. As is well known, each pulse that sequentially increments in the command pulse train corresponds to each (instantaneous) command position that sequentially increments, and the total number of pulses corresponds to the target position to be reached. The pulse generation speed, that is, the pulse generation time interval corresponds to the drive speed of the pulse motor. In this embodiment, command pulse generating means for generating a command pulse train with a predetermined speed pattern is included inside the controller 1. Such command pulse generating means per se is well known and will not be described in detail.

The up / down counter 22 counts the command pulses given from the interface 20,
The position detection pulses of the M-axis pulse motor 18 given from the M-axis detection rotary encoder 19 are subtracted and counted. Therefore, the difference m between the current command position indicated by the command pulse train and the actual position of the M-axis pulse motor 18 is
It is obtained by the up / down counter 22. Data indicating the difference m is given to the CPU 2 via the interface 23. As can be easily understood, the up / down counter 22 may of course be built in the controller 1. Also, an absolute position sensor can be used as the rotary encoder 19 for detecting the M-axis. In that case, instead of the up / down counter 22, the absolute value of the motor position actually detected from the absolute value of the current command position is used. Needless to say, the arithmetic circuit for subtraction is used.

As an example, an example in which the M-axis pulse motor 18 has 50 rotor teeth and a stator of 5 phases and is driven with a resolution of 0.36 degrees per command pulse by half step drive will be described below. . In this case, the rotation angle corresponding to one electrical angle cycle for driving and controlling the pulse motor is 7.2 degrees, which corresponds to 20 command pulses. The M-axis detection rotary encoder 19 is assumed to generate one pulse with a resolution of 0.36 degrees corresponding to the resolution of the M-axis pulse motor 18.

The torque of the pulse motor will be described with reference to FIG. FIG. 3A shows a state where the stator teeth and the rotor teeth of the pulse motor are in agreement with each other, which means that the current command position instructed by the command pulse and the actual rotor position are completely the same. It is a symbolic representation of what is happening. That is, the relative load with respect to the driving force of the pulse motor is 0.
In this case, the difference m between the current command position and the actual position of the pulse motor 18 is zero.

On the other hand, when the relative load is 0, the maximum torque in the pulse motor is
The actual rotor position is an electrical angle π with respect to the current command position.
It is known that the position is shifted by / 2. FIG. 3B shows symbolically the relationship between the stator and the rotor at such a maximum torque. That is, when the actual rotor position deviates from the current command position by an electrical angle of π / 2, the force to pull back to the positional relationship as shown in FIG. It will be the maximum. In this case, the load direction is indicated by L with respect to the rotation direction R of the pulse motor. If it deviates from this, step-out will occur. The electrical angle π / 2 is 5 pulses in the above example when converted into the number of command pulses.
In other words, if the difference m between the current command position and the actual position of the pulse motor 18 is in the range of 0 to 4, no step-out has occurred, and if m = 4 at that time, the torque is maximum. It will be.

As can be understood from the above, the force acting on the rotor against the load relative to the pulse motor driving force (that is, the force trying to attract in the state of relative load 0 as shown in FIG. 3a). ) Acts in the L direction of the figure,
There is a delay in the actual rotation of the motor. That is, the difference m between the current command position and the actual position of the pulse motor 18 becomes positive. The relative load to the pulse motor driving force is R in the figure.
When acting in the direction, the actual rotational position of the motor leads the commanded position, and the difference m becomes negative. Therefore, the allowable range of the difference m is −4 ≦ m ≦ + 4, and if the difference m exceeds ± 5, it means that step-out has occurred. Therefore, m ≦ −
When 5 or + 5 ≦ m, a step-out alarm process is performed.

In this embodiment, the difference m is determined by the up / down counter 22 by the direct addition / subtraction count of the command pulse train and the position detection incremental pulse train. Therefore, the rotary encoder for detecting the M-axis position is used. The mounting origin of 19 is accurately adjusted so as to match the state of relative load 0 as shown in FIG. Of course, the mounting origin alignment of the rotary encoder 19 for detecting the M-axis position is not limited to the mechanical origin alignment, but may be performed by addition or subtraction of an appropriate origin offset value, but this will not be described in detail here.

In this embodiment, the pulse generation speed of the command pulse train is increased by using the relative increase / decrease fluctuation tendency of the load of the pulse motor 18 and the delay or advance state of the actual motor rotation position with respect to the current command position as parameters. The speed adjustment data for this purpose is generated, and the pulse generation speed of the command pulse train generated from the controller 1 is controlled to be increased by this speed adjustment data. That is, the pulse generation speed (which is defined as a reference speed P) defined by a predetermined speed pattern as shown in FIG. As an example, the pulse motor 18
The increase rate n is generated by using the relative increase / decrease variation tendency of the load and the delay or advance state of the actual motor rotation position with respect to the current command position as parameters. Then, the rate n is multiplied by the reference speed P at that time to generate speed adjustment data α. Here, α = P · n. Then, this speed adjustment data α is added to the reference speed P at that time, and the pulse generation speed P ′ that has been accelerated is controlled.
To occur. Here, P ′ = P + α. In this way, the controller 1 generates a command pulse train in accordance with the pulse generation speed P'that has been accelerated.

In order to detect the relative increase / decrease fluctuation tendency of the load of the pulse motor 18, as an example, the difference m between the current command position and the actual position obtained by the up / down counter 22 is used, and the above Based on the change in the difference m, the increasing / decreasing tendency of the relative load in the pulse motor 18 is determined. Further, the delay or advance state of the actual motor rotation position with respect to the current command position is indicated by the difference m between the current command position and the actual position obtained by the up / down counter 22. Therefore, the data of the difference m between the current command position and the actual position obtained by the up / down counter 22 is fetched by the controller 1 and used as a parameter or for creating a predetermined parameter. When the increase / decrease variation tendency of the relative load of the pulse motor 18 is determined based on the data of the difference m, for example, the data of the difference m is periodically fetched and the data of the previous difference m (this is referred to as m0) and the current time are taken. The data of difference m (this is m1
The difference m0-m1 (this is referred to as c) is calculated. If c = m0-m1 is positive, it means that the difference m between the actual position and the current commanded position is smaller than the previous time, and the load tends to decrease. If c = m0-m1 is negative, it means that the difference m between the actual position and the current command position is larger than the previous time, and the load tends to increase.

In this embodiment, the acceleration control is generally performed in the following control modes I to IV using the load increase / decrease fluctuation tendency and the delay or advance state of the actual motor rotational position with respect to the current command position as parameters. I am trying to do it. FIG. 4 is a schematic diagram of each of the control modes I to IV. Note that the allowable difference m
Is -4 ≦ m ≦ + 4, c is −8 ≦ c ≦ +
8 can be taken as a value, but in the case of an extreme load fluctuation, n = 0 and no speed-up control is performed, and the load fluctuation is -4≤c≤ + 4.
In the range of, the control according to the following control modes I to IV is performed.

Control Mode I (FIG. 4a): Load parameter condition: No load fluctuation (c = 0), or load tends to increase (-4≤c <0). Actual position advance / delay parameter condition: The actual position is behind the command position (1 ≦ m ≦ 4) or the actual position matches the command position (m = 0). Control content: In this case, the following five types of control are performed. If m = 4, there is a positional relationship of the maximum torque, and if the speed is increased, there is a possibility that the actual rotation may fall out of step without catching the command, so there is no room for speed increase. Therefore, the increase rate n = 0. If m = 3, it is just before the maximum torque,
There is some room for speeding up. Therefore, the increase rate n is set to 0.05. As a result, an appropriate amount of delay is set so that the maximum torque is reached (achievement of high speed and high torque). If m = 2, it is just before the maximum torque, and there is a little room for speeding up. Therefore, the increase rate n = 0.
Set to 1. As a result, an appropriate amount of delay is set so that the maximum torque is reached (achievement of high speed and high torque). If m = 1, it is three torques before the maximum torque, and there is a little more room for acceleration. Therefore, the increase rate n is set to 0.15. As a result, an appropriate amount of delay is set so that the maximum torque is reached (achievement of high speed and high torque). If m = 0, it is four points before the maximum torque, and there is more room for speeding up. Therefore,
The maximum increase rate n is 0.2. As a result, an appropriate amount of delay is set so that the maximum torque is reached (achievement of high speed and high torque).

Control Mode II (FIG. 4b): Load parameter condition: No load fluctuation (c = 0), or load tends to increase (-4≤c <0). Lead / lag of actual position Parameter condition: The actual position is ahead of the command position (-4≤m≤-1). Control content: In this case, the actual position is ahead of the command position, and the load is not changing or is increasing, so that the load is applied in the direction L opposite to the rotation. Thus, since the load is applied in the direction L opposite to the rotation and the actual position is ahead of the commanded position, there is sufficient room for speeding up. That is, the change of the command position can be sufficiently accelerated. Therefore, the maximum increase rate n is set to 0.2. As a result, the speed can be increased.

Control Mode III (FIG. 4c): Load parameter condition: The load tends to decrease (1 ≦ c ≦
4). Actual position advance / delay parameter condition: The actual position matches the command position (m = 0), or the actual position is behind the command position (1 ≦ m ≦ 4). Control content: In this case, the load tends to decrease, so even if the speed is moderately increased, there is no fear of step-out, and there is room for acceleration. Therefore, if 0 ≦ m ≦ 4, the maximum increase rate n = 0.
Set to 2. Accordingly, when the positional relationship of the maximum torque is m = 4, the position can be held and the speed can be further increased. Also, even if the positional relationship of the maximum torque is not reached, it is possible to further speed up the speed, and the current torque position is maintained or the maximum torque is increased by advancing the command position in response to a decreasing load fluctuation. It is also possible to make it closer to the positional relationship of (m = 4) (achievement of high speed and high torque).

Control mode IV (FIG. 4d): Load parameter condition: The load tends to decrease (1≤c≤
4). Lead / lag of actual position Parameter condition: The actual position is ahead of the command position (-4≤m≤-1). Control content: In this case, since the actual position is ahead of the command position and the load tends to decrease, a load is applied in the rotation direction R (a negative load is applied). When a load is applied in the rotation direction R as described above, the positional relationship of m = -4 corresponds to the positional relationship of maximum torque. In this case, the following four types of control are performed. If m = -4, there is a positional relationship of maximum torque, so
This positional relationship is maintained without increasing the speed. Therefore, the increase rate n
= 0. If m = -3, it is just before the maximum torque, and there is a little room for acceleration. Therefore, the increase rate n = 0.
05. If m = -2, it is two before the maximum torque, and there is a little room for increasing the speed. Therefore, the increase rate n =
Set to 0.1. If m = -1, it is three before the maximum torque, and there is a little more room for acceleration. Therefore, the increase rate n is set to 0.15. Therefore, also in this case, it is possible to perform control suitable for pursuing high speed and high torque.

The above control is performed by the CPU 2 in the controller 1.
Executed by An example of the M-axis pulse motor drive speed correction control routine in that case is as shown in FIGS. In FIG. 5, in step S1, it is checked whether the M-axis pulse motor 18 is operating. In the next step S2, the output data m of the counter 22 is taken into the internal register as "m0". In the next step S3, the time for sampling the data of the difference m between the actual position and the command position (time interval for subtracting m0-m1 = c)
A predetermined timer T for setting is started.

In the next step S4, it is checked whether or not the value of the captured difference m is -5 or less. If m ≦ −5, the actual position is too advanced and step out has occurred, so the procedure goes to step S5, an alarm is sounded, the operation is stopped, and this control routine is ended. If the result of step S4 is NO, go to step S6 and take in the difference m
It is checked whether the value of is within a predetermined allowable range −4 ≦ m ≦ + 4. If the result of step S6 is NO, then + 5 ≦ m, the actual position is too late, and step-out is occurring, so go to step S5, sound an alarm, and stop the operation. Exit the routine. If the result of step S6 is YES, the process goes to step S7 to continue the process. In step S7, it is checked whether the current routine is the first routine immediately after starting the M-axis pulse motor 18. If YES, the process proceeds to step S8 to instruct to generate the command pulse at the reference speed P (which is the reference speed according to the predetermined speed pattern as described above).
If NO, the process proceeds to step S9, the rate n determined at that time is multiplied by the reference speed P at that time to generate speed adjustment data α, and this speed adjustment data α is used as the reference at that time. It is added to the speed P to generate a pulse generation speed P ′ that has been accelerated. And this pulse generation rate P '
To generate a command pulse according to. The processing for generating the command pulse train at the speed P or P'instructed in step S8 or S9 is performed by a command pulse train generation processing routine, but that point is not shown.

In the next step S10, it is checked whether the timer T has timed out. When the set time of the timer T arrives, the process goes to step S11, and the output data m of the counter 22 is taken into the internal register as "m1". In the next step S12, the timer T is restarted for the next sampling. In the next step S13, the difference data m1 of the current sampling timing is subtracted from the difference data m0 of the previous sampling timing stored in the register, and the subtraction result c = m0-m1 is stored in the internal register. After step S13, the process proceeds to step S14 in FIG.

In FIG. 6, in step S14, the data c stored in the register is used to check whether the above-mentioned load parameter condition "1≤c≤4" is satisfied. If “1 ≦ c ≦ 4” is satisfied (that is, the load tends to decrease), the process branches to step S15 and the processes of steps S15 to S23 are performed. If "1≤c≤4" is not established, the process proceeds to step S24, and it is checked whether the above-mentioned load parameter condition "-4≤c≤0" is established. If “−4 ≦ c ≦ 0” is satisfied (that is, the load tends to increase or does not change),
The process branches to step S25 and the processes of steps S25 to S33 are performed.

The case where "1≤c≤4" is satisfied (that is, the load tends to decrease) will be described.
In steps S15 to S18, the difference data m1 of the current sampling timing is used to control the above-mentioned control mode III or IV.
Check which of the lead / lag parameter conditions of the actual position in is satisfied. If 0 ≦ m1 ≦ 4 is satisfied (the actual position is behind or in synchronism with the command position), step S15 is YES,
In step S20, the increase rate n is set to the maximum value n = 0.2. Thereby, the control corresponding to the above-mentioned control mode III is performed. When the actual position is ahead of the commanded position, if m1 = -1 is satisfied, step S16 is YES, the process proceeds to step S21, and the increase rate n is set to n =
Set to 0.15. If m1 = -2 holds, step S17 is YES and step S22.
And set the increase rate n to n = 0.1. Also, m1
==-3 is true, step S18 is YES, and the process proceeds to step S23 to set the increase rate n to n = 0.05. If m1 = -4, step S18.
Is NO, the process proceeds to step S19, and the increase rate n is set to n = 0.
Set to. Thereby, the control corresponding to the above-mentioned control mode IV is performed.

When "-4≤c≤0" is satisfied (that is, when the load tends to increase or there is no fluctuation).
In step S25 to S28, using the difference data m1 of the current sampling timing, it is checked which of the lead / lag parameter conditions of the actual position in the control mode I or II described above is satisfied. −
If 4 ≦ m1 ≦ −1 is satisfied (the actual position is ahead of the commanded position), step S25 is YES and the process proceeds to step S30 to set the increase rate n to the maximum value n = 0.2.
Set to. Thereby, the control corresponding to the above-mentioned control mode II is performed. Even when m1 = 0 is satisfied (the actual position matches the command position), step S25 is YES and the process goes to step S30 to set the increase rate n to the maximum value n = 0.2. Thereby, the control corresponding to the control mode I described above is performed. When the actual position is behind the commanded position, if m1 = 1 is satisfied, step S26 is YES, the process proceeds to step S31, and the increase rate n
To n = 0.15. If m1 = 2 holds, step S27 is YES and step S27
Go to 32 and set the multiplication factor n to n = 0.1. Also,
If m1 = 3 is established, step S28 is YES and the process proceeds to step S33 to set the increase rate n to n = 0.05. If m1 = 4, step S28
Is NO, the process proceeds to step S29, and the increase rate n is set to n = 0.
Set to. Thereby, the control corresponding to the control mode I described above is performed.

Steps S19 to S23, S29 to S33
After performing the processing for setting the respective multiplication factors n to the respective predetermined values in, the procedure goes to step 35. Also, steps S14 and S2
When the determination results of 4 are all NO, that is, when the load fluctuation is in the range of −8 ≦ c <−4 or +4 <c ≦ + 8,
In step S34, the increase rate n is set to n = 0.
Then, it goes to step S35. In step S35,
Check whether the timer T has timed out. If the time is up, one processing cycle ends, and the process returns to step S1 in FIG. Returning to step S1 in FIG. 5, the same processing as described above is repeated and the next processing cycle is performed.
In this way, the data c indicating the load variation tendency is constantly obtained based on the difference m between the actual position and the commanded position, and the speed increase rate n is determined according to the current difference m and the current difference m1. Adjustment data α is generated. Then, the current reference speed P determined according to the predetermined command pulse generation speed pattern is changed by the speed adjustment data α at that time, and the generation speed of the command pulse train is speed-up controlled according to the speed increase rate n. Become.

When the generation speed pattern of the command pulse train is in the deceleration region, it is preferable not to perform the above-mentioned speed increase control. In the embodiment of FIGS. 5 and 6, one processing cycle corresponds to two cycles of the timer T, and at the end of each timer time, the output m of the counter 22 is sampled and set as the previous value m0 and the current value m1. Although the resist is registered, the processing is not limited to this, and one processing cycle may correspond to one cycle of the timer T. In that case, for example, steps S10, S11, S1
2 may be omitted, and the output m of the counter 22 may be registered as the current value m1 in step S2. At this time, the current value m1 up to that time may be shifted as the previous value m0 and registered.

The number of phases of the pulse motor is not limited to five, but may be any other suitable number of phases such as three, and the number of teeth may be appropriate. If the specifications of the pulse motor differ, the value of the difference m between the actual position and the commanded position corresponding to the maximum torque (m = 4 in the above) also differs, and the specific numerical values in FIGS. 5 and 6 also differ. Of course.
Further, it goes without saying that the value of the multiplication factor n and the manner of setting the same are not limited to those shown in the above embodiment. The processing for speed-up control in the controller 1 is not limited to the execution by the software program of the microcomputer as shown in FIGS. 5 and 6, and may be executed by a hardware circuit that realizes an equivalent function. Good. Further, any driving method may be used in the pulse motor driver circuit 21, as long as it drives the pulse motor in accordance with the given command pulse train. The scope of the pulse motor drive control device and method according to the present invention is not limited to the complete implementation of the control shown in the above-described embodiment, and only the control that produces an effective effect is partially implemented. Including that. The pulse motor drive control device and method according to the present invention is not limited to the M-axis pulse motor shown in the above embodiment, but may be applied to an XY drive pulse motor in an embroidery machine or a pulse motor used in a drive mechanism in other sewing machines. Can be applied. Further, it can be applied to a pulse motor used in a drive mechanism having the same problems of high load, load fluctuation, rattling, and the like.

[0040]

As described above, according to the present invention, the pulse generation of the command pulse train is performed by using the increasing / decreasing fluctuation tendency of the load of the pulse motor and the delay or advance state of the actual motor rotation position with respect to the current command position as parameters. Since the speed is controlled to be increased / not increased, even if the delay or advance of the actual motor rotation position with respect to the current command position is the same, it differs according to the load increase / decrease fluctuation tendency. Speed-up control can be performed, and efficient speed-up can be achieved, which enables high-speed operation. For example, when the delay of the actual motor rotational position with respect to the current command position is the amount of delay that produces the maximum torque, if the relative load tends to increase, speed-up control is not performed, while on the other hand, it tends to decrease. In that case, control can be performed so as to perform speed-up control. That is, even if the degree of delay of the actual motor rotational position with respect to the current command position is the same, different speed increasing control is performed according to the relative load increasing / decreasing tendency at that time. As a result, the speed-up control can be efficiently performed, and the pulse motor can be operated at high speed. Further, high torque operation and high speed operation can be realized by performing the step-up speed increasing control according to the delay or advance state of the actual motor rotational position with respect to the current command position. Therefore, the sewing machine can be operated at high speed, and the productivity of embroidery sewing and other sewing operations can be improved.

Further, according to the pulse motor drive control method of the present invention, the deviation (m) between the current command position and the actual rotational position is the predetermined position deviation (m =) that produces the maximum torque.
Since the control to increase the drive speed of the pulse motor is performed so that the speed increase rate becomes higher as it becomes smaller than 4), a large delay will occur due to the speed increase as the position shift becomes smaller, and in any case, the maximum speed is always reached. It becomes possible to perform control so as to maintain a delay close to the delay that produces torque, and thus, possible to operate as fast as possible while maintaining high torque operation. Further, when the load applied to the pulse motor tends to be relatively reduced, the speedup rate should be increased even if the deviation corresponds to the predetermined positional deviation (for example, at the maximum increase rate n = 0.2). By performing the speed-up control, it is possible to positively advance the speed-up control after confirming that there is no risk of step-out due to the relative decrease tendency of the load, and it is possible to further speed up the operation. Further, when the load applied to the pulse motor tends to relatively decrease, a predetermined maximum speed increase rate (n = 0.
If the acceleration control is performed in 2), even higher speed operation becomes possible.

[Brief description of drawings]

FIG. 1 is an overall configuration block diagram of a control system showing an embodiment of an embroidery sewing machine to which the present invention is applied.

FIG. 2 is a diagram showing a typical example of a speed pattern of a command pulse train for a pulse motor.

FIG. 3 is a diagram showing a positional relationship between a stator tooth and a rotor tooth for explaining a torque generated in a pulse motor.

FIG. 4 is a schematic diagram for explaining an example of speed-up control that is performed according to an embodiment of the present invention with a load increase / decrease fluctuation tendency and a delay or advance state of an actual motor rotation position with respect to a current command position as parameters. Fig.

FIG. 5 is a flowchart showing an example of a processing program executed by the controller of FIG. 1 in order to execute an embodiment of speed-up control according to the present invention.

FIG. 6 is a flowchart showing an example of a processing program executed by the controller of FIG. 1 in order to execute an embodiment of speed-up control according to the present invention in the latter half portion.

[Explanation of symbols]

1 ... Controller, 2 ... CPU, 18 ... M-axis pulse motor, 19 ... M-axis detection rotary encoder, 21 ... M-axis pulse motor driver circuit, 22 ... Up-down counter.

Claims (9)

[Claims] 1. A pulse motor drive control device in a sewing machine, comprising: a command pulse generating means for generating a command pulse train corresponding to a command position in a predetermined speed pattern; and a driver means for driving a pulse motor in accordance with the command pulse train, Position detection means for detecting the rotational position of the pulse motor, and for detecting whether the relative load of the motor rotation shaft with respect to the driving force of the pulse motor tends to increase or tends to decrease. Load fluctuation tendency detection means, in response to the output of the position detection means and the load fluctuation tendency detection means, the load fluctuation trend, the delay or advance state of the actual position relative to the current command position as a parameter , Pulse speed adjusting means for generating speed adjustment data for increasing the pulse generation speed of the command pulse train A pulse motor drive control device for a sewing machine, characterized in that the pulse generation speed of the command pulse train generated from the command pulse generation means is controlled by the speed adjustment data. 2. The load fluctuation tendency detecting means, a calculating means for obtaining a difference between a current command position instructed by the command pulse generating means and an actual position detected by the position detecting means, and with the passage of time. The pulse motor drive control device for a sewing machine according to claim 1, further comprising: a determination unit that determines an increase / decrease tendency of a load applied to a rotation shaft of the pulse motor based on a change in the difference. 3. The pulse speed adjusting means generates the speed adjusting data with the load increase / decrease tendency judged by the judging means and the difference value obtained by the calculating means as parameters. Item 3. A pulse motor drive controller in the sewing machine according to Item 2. 4. The pulse speed adjusting means, when the deviation of the actual position from the current command position is within a predetermined range,
2. The pulse motor drive control device for a sewing machine according to claim 1, wherein a plurality of stages of speed adjustment data are generated according to the deviation. 5. The pulse speed adjusting means increases the speed increasing rate stepwise as the deviation becomes smaller than that based on the state where the deviation of the actual position with respect to the current command position causes the maximum torque. The pulse motor drive control device for the sewing machine according to claim 4, wherein the speed adjustment data is generated in the sewing machine. 6. The speed adjustment by the pulse speed adjusting means is not performed when the speed pattern of the command pulse train generated by the command pulse generating means is at least in the deceleration region. A pulse motor drive controller in the sewing machine described. 7. A first step of generating a command pulse train for driving a pulse motor, a second step of detecting a rotational position of the pulse motor, and a current command position and an actual command position indicated by the command pulse. And a third step of detecting a deviation from the rotational position of the vehicle, and the deviation detected in the third step with reference to a predetermined positional deviation between the current command position and the actual rotational position when the maximum torque is generated. And a fourth step of performing control for increasing the drive speed of the pulse motor so that the speed increase rate increases as the position deviation becomes smaller than the predetermined position deviation. 8. When the load applied to the pulse motor tends to relatively decrease, the speedup rate is increased even if the deviation detected in the third step corresponds to the predetermined positional deviation. The pulse motor drive control method for a sewing machine according to claim 7, further comprising a fifth step of performing speed-up control. 9. The sewing machine according to claim 7, further comprising a sixth step of performing speed increasing control at a predetermined maximum speed increasing rate when the load applied to the pulse motor tends to relatively decrease. Pulse motor drive control method.