JPS61266097A - Control system for pulse motor - Google Patents

Abstract

PURPOSE:To improve the decrease in an output torque in a low speed rotation range by increasing the pulse width of a pulse current for exciting a coil when a rotating speed is decelerated. CONSTITUTION:A counter 57 for deciding the pulse width of pulse current by counting the prescribed clock signals is provided. A counted value is selected from a signal width counter value table by a controller 51, and a set signal K is written in the counter 57. Thus, the counted value of the counter 57 is increased in response to the decrease in the rotating speed to increase the exciting period of the coil by the exciting current, thereby holding the similar output torque to that at normal rotation time even in a low speed rotation range.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a control method for a pulse motor, and in particular, in a method in which each coil of a pulse motor is excited and rotated with a pulse current, a decrease in output torque in a low speed rotation range is avoided. The present invention relates to a pulse motor control method suitable for improving.

[Background of the invention]

Recently, with the spread of digital processing, pulse motors have come into widespread use as drive sources for various mechanisms because they are easier to control, such as rotational speed, than DC motors. The pulse motor is generally controlled by the circuit configuration shown in FIGS. 3 and 4. That is, the control device 1 first outputs phase data a that determines the excitation conditions of the coils 9 to 12 in the pulse motor 8 to the latch circuit 2, and writes it in with a set signal.

Next, the count value g that determines the phase advance period (rotation speed) of the pulse motor 8 is similarly outputted to the counter circuit 6, and written with the set signal i. First, the phase data b of the latch circuit 2 is written into the latch circuit 3 by starting the operation of subtracting the count value g with the clock signal f of and outputting the borrow signal e after the subtraction operation for the count value g. This sends the phase data signal C to the driver circuit 4, causing the pulse motor 8 to rotate. The 5th rotation is based on the phase data c1 to c4 of the latch circuit 3, and the buffer circuit 130 shown in FIG.
~33. Transistors 13 to 16 operate, and coils 9 to
This is to excite 12.

Second, it instructs the control device 1 to write new phase data a into the latch circuit 2 again. Third, the counter circuit 7 is activated.

The activated counter circuit 7, like the counter circuit 6, sets the counting (output) signal d to High state at the same time as it starts the subtraction operation by the clock signal f, and after the subtraction operation for the preset count value, the counter circuit 7 turns to the Low state. %I state. As a result, the buffer circuit 29 of the driver circuit 4
．． Transistors 17 and 18 operate, and the above phase data c1
In conjunction with the coil excitation conditions of ~c4, a bowl-shaped excitation current 11 shown in FIG. 5 is applied to the coils 9 to 12 to rotate the pulse motor 8. In addition, in Figure 5! 1*ia are the output period of the borrow signal e due to the subtraction operation of the counter circuit 6, and the counting signal d due to the subtraction operation of the counter circuit 7, respectively.
is the output time. Furthermore, the pulse motor 8 rotates continuously by automatically reloading the counter circuits 6 and 7 and repeating the subtraction operation.

FIG. 7 shows a recirculation banknote handling device (ATM) that stacks banknotes using the pulse motor control method described above.
) shows part of the stack mechanism using an impeller.

The banknotes 47 are stacked by providing an impeller 43 between the conveyance path 41 and the storage section 45 in order to accumulate the banknotes 47 on the conveyance path 41 in the storage section 45, and by rotating the impeller 43 with the pulse motor 8. Feather 46.4 with banknotes 47 from 41
8, rotate it as it is, carry it to the vicinity of the entrance of the storage section 45, put the banknote 47 against the banknote removal plate 44,
The receiver is extracted from between the blades 46 and 48 and placed in the storage section 45.

When the single impeller 43 is rotated at a constant speed in the banknote stacking operation described above, the amount of banknotes from the conveyance path 41 may be reduced depending on the transfer timing, and the banknotes 47 may hit the tips of the blades 46 and 48 and cannot be sandwiched between the blades. , it becomes impossible to organize and accumulate the banknotes 47 in the storage section 45.

As a measure to prevent this problem, as shown in the seventh cause, a banknote detection sensor 42 is provided in the middle of the conveyance path 41, and by knowing the positional relationship between the blades 46 and 48 and the banknotes 47 being conveyed, There is a method of changing the rotation speed of the wheel 43 and adjusting the rotation of the pulse motor 8 so that when the bill 47 reaches the impeller 43, the space between the blades 46 and 48 forms an entrance. In this adjustment, the rotation of the pulse motor 8 must be varied from low speed to high speed (for example, 50 to 1000 PPS) in order to ensure that the banknotes 47 can be stacked in the storage section 45 no matter what the transport state of the banknotes 47 is. There is. Therefore, when varying the rotational speed of the pulse motor, as shown in FIG. 6, the output period t of the borrow signal e is
This is achieved by widening 1 to t2, but in the low speed rotation range, the peak value 11 also decreases to 12, resulting in a situation where the output torque of the pulse motor 8 becomes small and the rotational operation of the impeller 43 becomes unstable. was. Incidentally, related methods of this type include 1, for example, Japanese Patent Application Laid-open No. 57-203.
No. 578, JP-A-58-7385, and the like.

[Purpose of the invention]

An object of the present invention is to solve such conventional problems, and to improve the decrease in output torque of a pulse motor in a low-speed rotation range and to stabilize the stacking operation of banknotes by a simple and inexpensive method. The object of the present invention is to provide a pulse motor control method.

[Summary of the invention]

In order to achieve the above object, 1 the pulse motor control method of the present invention is a method in which a pulse motor is rotated by passing a pulse current therein, and the pulse width of the pulse motor is determined by counting a predetermined clock signal f. Counter circuit 57
and means (control device 51) for setting a count value j in the counter circuit, the setting means changing the count value in accordance with the rotational speed of the pulse motor, and controlling the pulse of the pulsed current. It is characterized by controlling the width.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of pulse motor control according to the present invention, and FIG. 2 is an operation time chart of FIG. 1.

In FIG. 1, 51 to 56 and 58 are respectively the control device 1 to the force counter circuit 6 and the pulse motor 8 shown in FIG.
, and 57 is a decrement counter similar to the counter circuit 7 in FIG. 3, but instead of setting the count value in advance, it is specified by the count data j from the control device 51 and written in the set signal. , also *a ””
g t l is also the same as each signal in FIG. 3 described above.

As shown in the flowchart of FIG. 9, the control device 51 checks whether there is a request to change the rotational speed every time it inputs the borrow signal e of the counter circuit 56 (step 101), and if there is a request, it first changes the rotation speed. , Select the count value gn most suitable for the above request from the speed counter value table 61 shown in FIG. 10, and write it to the counter circuit 56 with a set signal i (step 102). 0th order, 10th order
Select a count value jn corresponding to the above-selected counter value gn from the d signal width counter value table 62 shown in the figure,
A set signal is written to the counter circuit 57 (step 103), and then new phase data a that causes the pulse motor 58 to rotate continuously is written to the latch circuit 52 using a set signal (step 104). On the other hand, when there is no request to change the rotational speed, only the process of step 104 is executed. Regarding the operation after writing the count value, as in FIGS. 3 to 5 described above, while the counting signal d is in the High state, the excitation current If is applied to excite the coils 9 to 12 and the pulse motor 58 is activated. Rotate.

Based on the above control flow, for example, as shown in FIG. 2, the pulse motor 58 is rotated when the output period of the borrow signal e is ilt and the output time of the signal d is t3.
, the output period t2. When the rotational speed of the pulse motor is slowed down in the state of output time t4, the rotational speed (r
pm)-output torque (Kg-cit) characteristic, the output torque of the pulse motor 58 is curve A. That is,
Conventionally, the output torque decreased in the low speed rotation range as shown by curve B in FIG.
By lengthening the coil excitation period (ta→14) according to No. 1, it is possible to maintain the output torque at the same level as during normal rotation even in the low-speed rotation range as shown by curve A.

To take advantage of this effect, use the above-mentioned recycling-type banknote handling bag!
When the above-mentioned pulse motor control method is used for the banknote stacking mechanism in an ATM (ATM), smooth low-speed rotation of the impeller 43 is enabled by increasing the output torque of the pulse motor 8 in the low-speed rotation range, and the blades 46 The moving speed of the impeller 43 can be changed rapidly based on the positional relationship between the banknotes 47 and the banknotes 47 being conveyed. therefore,
For example, if two banknotes 47 are conveyed in succession, when the first banknote 47 approaches the impeller 43, the rotation speed of the impeller 43 is set to the slowest, and the next two banknotes are The banknotes 47 are also moved while being sandwiched between the same blades 46 and 48, and the banknotes 47 are transferred into the storage section 45. Also, when the positional relationship between the two reaches the impeller 43, the blades 46, 48
If the impeller 43 is in a relationship where it collides with the tip of the
This is done by speeding up or slowing down the rotational speed of the blades 46 and 48 to avoid collision and to sandwich the blades between the blades 46 and 48.

Next, another embodiment of the control procedure by the control device 51 will be described with reference to FIGS. 11 to 13.

In the control flow of FIG. 9 described above, the borrow signal e
The control device 51 used to write new phase data a to the latch circuit 52 for each input of , but by reducing the number of times of writing based on the A data table 63, the same The number of times the excitation current is applied to the phase coil is increased to obtain the waveform of the excitation current 11 shown in FIG. 13, and its peak value is set to 13 or i4.

That is, upon receiving the borrow signal e, the step 101 described above is performed.
After writing the count value gnt jn in the same way as in steps 103 to 103, the control device 51 checks the A data value set in the internal memory (step 104), and determines that the person's data value is '''
0'', the A data An corresponding to the count value gn+jn selected from the A data table 63 shown in FIG. Write new phase data a such that Note that the time chart in Figure 13 is for the case where the A data value is "2", and phase data C is written with the second borrow signal e. In Figure 13, the output time of the counting signal d is indicated by the solid line Alternatively, the peak value of the exciting current 11 is set to 13 or i4 by changing as shown by the dotted line.

In this way, by increasing the number of times the excitation current 11 is applied during the same phase data to increase the current value, and combining it with the output time value of the counting signal d, the value of the excitation current 11 flowing through the coils 9 to 12 can be determined. It becomes possible to precisely control the

〔Effect of the invention〕

As explained above, according to the present invention, the rotation speed of the pulse motor is slowed down and the count value of the counter circuit 57 is increased to lengthen the pulse width of the pulse current for coil excitation. without using
It is possible to improve the decrease in output torque in the low-speed rotation range and stabilize the stacking operation of banknotes.

[Brief explanation of drawings]

FIG. 1 is a configuration block diagram showing an embodiment of pulse motor control according to the present invention, FIGS. 2 and 13 are operation time charts of FIG. 1, and FIG. 3 is a configuration block diagram of conventional pulse motor control. FIG. 4 is a circuit diagram of the driver circuit, FIGS. 5 and 6 are operation time charts of FIG. A relationship diagram between the rotational speed (rp-) and output torque (Kg-am) of the pulse motor, FIGS. 9 and 11 are control flowcharts, and FIGS. 10 and 12 are for explaining the pulse motor control according to the present invention. FIG. 1.51: Control device, 2, 3, 52. 53: Latch circuit, 4, 54 driver circuit, 5.55: Clock signal generation circuit, 6, 7, 56, 57: Counter circuit, 8.5
8: Pulse motor, 9-12: Motor coil, 13-1
8 Nidoran Sister, 19.20: Constant voltage diode,
21-28: Diode, 29-33: Buffer circuit,
34-4o: Resistor, 41: Conveyance path, 42: Banknote detection sensor, 43: Impeller, 44: Banknote removal plate, 45:
Storage section, 46, 48: Blade, 47: Banknote, 61: Speed counter value table, 62: d signal width counter value table, 63: A data table. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure □Rotational speed (rpm) Figure 9 Figure 10
Figure 11 @ Figure 12 Figure 13

Claims (1)

[Claims] (1) In a method in which a pulsed motor is rotated by passing a pulsed current, a counter circuit that counts a predetermined clock signal to determine the pulse width of the pulsed current, and a count value is set in the counter circuit. means, wherein the setting means changes the count value in accordance with the rotational speed of the pulse motor to control the pulse width of the pulsed current.