JPS63190596A - Driving gear for stepping motor - Google Patents

Abstract

PURPOSE:To enable arbitrary split driving to be performed with one device, by changing split number setting signal for input to an address arithmetic cir cuit. CONSTITUTION:From an address arithmetic circuit 11, address signal AD is outputted through advancing command pulse, rotational direction input signal, step number setting signal N, and split number setting signal M. The address signal AD is outputted to the first and the second memory units 12, 13 of a ROM. With the first memory unit 12 and a second D/A converter 14, a first exciting current value setting signal forming circuit 16 is formed. With the second memory unit 13 and a second D/A converter 15, a second exciting current value setting signal forming circuit 17 is formed. By a stepping motor driving unit 18, exciting current for exciting a stepping motor 2 with two sorts of exciting current value setting signals for input signals is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stepping motor drive device that drives a stepping motor in a differential manner.

[Prior Art] A conventional stepping motor drive device of this type has a structure that only performs predetermined differential division driving.

[Problems to be Solved by the Invention] However, in such a stepping motor drive device, when driving other than the prescribed differential division drive, it is necessary to manufacture a stepping motor drive device suitable for the differential division drive. Since it is necessary to replace or switch connections to perform the desired differential division drive, there is a problem in that the equipment cost is high. Due to such constraints,
There was also the problem that it was not possible to perform differential division driving according to the purpose.

SUMMARY OF THE INVENTION An object of the present invention is to provide a stepping motor drive device that can perform desired differential driving with a single device.

[Means for Solving the Problems] The structure of the present invention for achieving the above object will be explained with reference to FIGS. 1 to 5 corresponding to the embodiments. rotation direction input signal and a step number setting signal N( However, N
4. is a positive integer) and the current position signal P indicating the current step position are human input signals, and when the rotation direction input signal is a forward rotation signal, P+N=K is added, and the rotation direction input signal is a reverse rotation signal. A first adder/subtractor 1 that subtracts P-N=K and outputs an output signal K, and inputs K to the output signal and a division number setting signal M of the basic step angle of the stepping motor 2. ≧M Crab≦
A discriminator 3 that determines whether the rotation direction is 0, the output signal, the division number setting signal M, and the rotation direction input signal as input signals, and when the rotation direction input signal is a normal rotation signal, (P
+N)-M=Y, for reverse signal (P-N)+M=Y
A second adder/subtractor 4 which adds and subtracts the output signal Y and outputs an output signal Y.
and the output signal Y and the discrimination signal of the discriminator 3 indicating whether K≧M or ≦O are used as input signals, and if the K≧M in the normal rotation state, the output signal Z is output. The output signal Y=(P+N)-M is output as follows, and the above K≧ in the forward rotation state.
If not M, then output signal Z as output signal =P+N
If the above is ≦0 in the reverse state, the front output signal Y = (P-N) + M is output as the output signal Z, and if the above is ≦0 in the reverse state, the output signal Z is output. A selection circuit 5 selects and outputs =P-N as an output signal, and latches the output signal Z of the selection circuit 5 at the rising edge every time a step command pulse is given, and uses the output signal Z as an address signal. a latch circuit 6 that outputs the signal ΔD; a delay circuit 8 that delays the address signal AD by a time width wider than the pulse width of the step command pulse and outputs it as the current position signal P; A phase switching signal output that outputs the step command pulse as a phase switching signal when the K≧M or the above ≦0 using the discrimination signal of the discriminator 3 of the K≧M or the above ≦0 as an input signal. circuit 9
and an excitation current value setting signal forming circuit 16, 17 which stores the pattern of the excitation current value setting signal for the stepping motor 2 and sequentially outputs the excitation current value setting signal in a predetermined pattern every time the address signal is input. and forming excitation currents for exciting the stepping motor 2 using the excitation current value setting signals from the excitation current value setting signal forming circuits 16 and 17 as input signals, and converting these excitation currents based on the phase switching signal. and a stepping motor drive unit 18 that switches to the excitation winding of a predetermined phase of the stepping motor 2.

[Operation] Such a stepping motor drive device can perform desired differential division driving by changing the division number setting signal M given to the second adjustment device 4. Further, by changing the step number setting signal N given to the first adjuster 1, differential division driving can be performed at desired differential division steps.

[Example] Hereinafter, this example will be described in detail with reference to FIGS. 1 to 5, in which this example is applied to a two-phase step pig motor drive system. The stepping motor drive equipment of this embodiment is shown in Figures 1 and 2.
As shown in the figure, it has a first adjuster 1. This first
The adder/subtractor 1 receives the rotation direction input signals of forward and reverse rotation, and the basic step angle of the stepping motor 2 [=360/ (
2・H・S) (H is the number of teeth of 0-ta, S is the number of phases)
] is divided into 1/M (where M is the number of divisions of the basic step angle) and the step number setting signal N (however, N is a positive integer) is used to determine how many steps to advance in divided steps, and the current step When the current position signal P indicating the position is used as an input signal, and the rotation direction input signal is a forward rotation signal, P+N=K.
is added, and when the rotation direction input signal is a reverse rotation signal, P-
After subtracting N=K, an output signal K is output.

The output signal of the first adder/subtractor 1 is applied to a discriminator 3, a second adder/subtractor 4, and a selection circuit 5.

The discriminator 3 uses the output signal and the dividing number setting signal M of the basic step angle of the stepping motor 2 as input signals.
It is designed to determine whether ≧M or ≦0.

The second adder/subtractor 4 outputs an output signal and a division number setting signal M.
and the rotational direction input signal as input signals, and if the rotational direction input signal is a normal rotation signal, the output signal @Y is Y= (P
+N)-M is output, and if it is a reverse signal, Y-(P-N>+M is output as the output signal Y).

The output signal Y is input to the selection circuit 5 together with the output signal. In addition, the selection circuit 5 inputs the discrimination signal of K≧M h' K≦0 from the discriminator 3, and outputs the signal Y=(P+N) as the output signal Z if K≧M in the normal rotation state. -M is output, and if K≧M in normal rotation state, outputs =P+N as output signal Z,
If ≦0 in the reverse state, output signal Y is output as output signal Z.
=(P-N)+M is output, and if ≦0 does not occur in the reverse state, =P-N is selected and output as the output signal Z.

The output signal Z of the selection circuit 5 is applied to the latch circuit 6. The latch circuit 6 latches the output signal 2 of the selection circuit 5 at the rising edge every time a step command pulse is applied, and outputs the output signal Z from the output terminal 7 as an address signal AD.

Further, the address signals ADG, tM are applied to the delay circuit 8. The delay circuit 8 is configured to delay the address signal AD by a time width wider than the pulse width of the step command pulse and output it as the current position signal P to the first adder/subtractor 1.

The output signal of the discriminator 3 is also given to a phase switching signal output circuit 9. The phase switching signal output circuit 9 is
The step command pulse and the determination signal of K≧M or ≦O of the discriminator 3 are input signals, and when K≧M or ≦0, the step command pulse is outputted from the output terminal 10 as a phase switching signal. It looks like this.

These first adder/subtractor 1, discriminator 3, second adder/subtractor 4, selection circuit 5, latch circuit 6, delay circuit 8, and phase switching signal output circuit 9 constitute an address calculation circuit 11.

The address signal AD output from the output terminal 7 is transmitted to the first .
It is adapted to be input to a second memory 12.13. The first memory 12 stores the rising pattern of the excitation current value setting signal of the basic step angle of the stepping motor 2 (for example, the rising pattern PTI in FIG. 4),
Every time the address signal AD is input, a digital weighting signal corresponding to the rising pattern of the excitation 11 current 1ilI setting signal corresponding to the address is output. The second memory 13 stores the falling pattern of the excitation current value setting signal for the basic step angle of the stepping motor 2 (for example, the falling pattern PT2 in FIG. 4), and stores it every time the address signal AD is input. Then, a digital weighting signal corresponding to the falling pattern of the excitation current value setting signal corresponding to the address is output.

These first. The weighted signals from the second memory 12.13 are transferred to the first . The signal is input to a second digital/analog converter (hereinafter referred to as a D/A converter) 14°15. These first and second D/A converters 14.
15 performs D/Δ conversion on the weighted signal and outputs an analog excitation current value setting signal.

The first memory 12 and the second D/A converter 14 form a first excitation current value setting signal forming circuit 16. The first excitation current value setting signal forming circuit 16 is configured to sequentially output an excitation current value setting signal in a predetermined rising pattern every time the address signal AD is input.

Further, the second memory 13 and the second D/A converter 15 form a second excitation current value setting signal forming circuit 17. This second excitation current value setting signal forming circuit 17 is configured to sequentially output an excitation current value setting signal in a predetermined falling pattern every time the address signal AD is input.

These first. Second encouragement! Current value setting formation circuit 16
．． Each excitation current value setting signal from 17 is provided to a stepping motor drive unit 18.

This stepping motor drive unit 18 uses two types of excitation current value setting signals as input signals to excite the stepping motor 2. Excitation currents IA, IB, I as shown in FIG.
A, IF3 are formed respectively, and these excitation currents l△, I
B, to l.

IB is switched based on a phase switching signal and applied to the excitation winding of a predetermined phase of the stepping motor 2.

Next, the operation of such a stepping motor drive device will be explained by taking as an example the case where the basic step angle is divided into eight (M=8>) as shown in FIG.

For example, if the rotational direction input signal is a normal rotation signal, the step number setting signal N is N-3, and the current position signal P is P=1 between A46B phases, the first adder/subtractor 1 outputs =P+
Add N=1 +3=4.

In the discriminator 3, since K=4 and M=8 are input, it is determined that the case is other than K≧M or ≦O. Since the second adder/subtractor 4 receives the normal rotation signal, it performs the subtraction of Y=(P+N)-M=(1+3)-8=-4 and outputs Y--4. In the selection circuit 5,
Since the discriminator 3 has determined that this is the other case, the output signal =4 is selected and output as the output signal Z. This output signal Z=4 is latched by the latch circuit 6 at the rising edge of the next step command pulse, and AD=4 is output as the address signal AD. In this case, the discriminator 3 has determined that it is another case, so the phase switching signal output circuit 10 does not output a phase switching signal even if the step command pulse is input. Therefore, stepping Tanabata 2 is the address A between A phase and B phase.
The 1st. Second excitation r41 current value setting signal forming circuit 1
At step 6.17, an excitation current value setting signal is generated, and the stepping motor drive unit 18 generates an excitation current for each phase according to this signal.

Next, for example, the rotation direction input signal is a normal rotation signal,
The step number setting signal N is N=3, and the current position signal P is A4.
When P=7 in fIB phase, the first adder/subtractor 1 adds =P+N=7+3=10. In discriminator 3, K=10 is input and M=8 is input, so KP
It is determined as M. Since the normal rotation signal is input to the second adder/subtractor 4, it performs the subtraction of Y=(P+N)-M=10-8=2 and outputs Y=2. Since the discriminator 3 has determined that K>M, the selection circuit 5 selects and outputs the output signal Y=2 as the output signal Z. This output signal Z
=2 is latched by the latch circuit 6 at the rising edge of the next step command pulse, and AD=2 is set as the address signal AD.
is output. In this case, since the discriminator 3 has determined that it is KPM, the phase switching signal output circuit 10 outputs the step command pulse as a phase switching signal. Therefore, the stepping motor 2 moves from address AD=7 between AID phases to B
An excitation current value setting signal is formed by the first and second excitation current value setting signal forming circuits 16 and 17 so that the rotation is driven in the normal direction in one step up to the angle corresponding to the address AD=4 between the phases Δ. and stepping motor drive unit 18
Excitation currents for each phase are generated accordingly.

Next, for example, the rotation direction input signal is a reverse rotation signal,
The step number setting signal N is N=3, and the current position signal P is A.
II When P=6 between the B phases, the first adder/subtractor 1 performs a subtraction of =6-3-3.

In the discriminator 3, since K=3 and M=8 are input, it is determined that it is KPM and neither K≧M nor K1-0. Since the second adder/subtracter 4 receives the reverse signal, it performs the addition of Y=(P-N)+M-3+8=11 and outputs Y=11.

In the selection circuit 5, since the discriminator 3 has determined that the case is otherwise, the selection circuit 5 selects and outputs =3 as the output signal Z. This output signal Z=3 is latched by the latch circuit 6 at the rising edge of the next step command pulse, and AD=3 is output as the address signal AD. In this case, discriminator 3
Since this is determined to be other cases, the phase switching signal output circuit 10 does not output a phase switching signal even if the step command pulse is input. Accordingly, the stepping motor 2 is driven reversely in one step from the address AD-6 between the AID phases to the angle corresponding to the address AD=3 between the AIDS phases. An excitation current value setting signal is formed in the second excitation current value setting signal forming circuit 16.17,
The stepping motor drive unit 18 generates corresponding excitation currents for each phase.

Next, for example, the rotation direction input signal is a reverse rotation signal,
The step number setting signal N is N=3, and the current position signal P is AI
In the case of P=1 between the D phases, the first adder/subtractor 1 has =
Subtract 1-3=-2.

Since the discriminator 3 receives K--2 and M-8 as input, it determines that K<O. In the second adder/subtractor 4, since the reverse signal is input, Y-(P-N)+M=-2+
8=6 is added, and Y=6 is output. Selection circuit 5
Here, since the discriminator 3 has determined that K<0, Y=6 is selected and output as the output signal Z. This output signal @
Z=6 is latched by the latch circuit 6 at the rising edge of the next step command pulse, and 80= as the address signal AD.
6 is output. In this case, since the discriminator 3 has determined that K<0, the phase switching signal output circuit 10 outputs the step command pulse as a phase switching signal.

Therefore, the stepping motor 2 is driven reversely in one step from the address AD=1 between the AID phases to the angle corresponding to the address AD-6 between the B and A phases. Second excitation current value setting signal forming circuit 16
．． 17, an excitation current value setting signal is formed, and a stepping motor drive unit 18 forms excitation currents for each phase according to this signal.

In the above embodiment, the present invention is applied to a two-phase stepping motor drive device, but the present invention is not limited to this, and can be similarly applied to an n-phase stepping motor drive device. It is.

Further, in the above embodiment, the memory of the excitation current value setting signal forming circuit stores only the rising or falling pattern of the excitation current value setting signal, but the memory of the excitation current value setting signal forming circuit stores only the pattern of one cycle of the excitation current value setting signal. Good too. Furthermore, the excitation current value setting signal forming circuit may be provided for each phase of the stepping motor 2.

[Effects of the Invention] As explained above, the stepping motor drive device according to Kinoe IIIJ can perform arbitrary differential division driving with one device by changing the division number setting signal M given to the second adder/subtractor. can be set. Further, by changing the step number setting signal N given to the first adder/subtractor, it is possible to select a desired differential division step and perform differential division driving at an arbitrary step angle with one device. In this way, in the present invention, since the step angle can be easily changed, at low speeds, a fine angle is used for smooth rotation, and at high speeds, the number of steps is switched to achieve high-speed rotation corresponding to the basic step angle or a drive and rotation speed close to this. can be made to do so. Fine-angle drive is required to perform smooth low-speed rotation, but fine-angle drive requires a higher input frequency when using conventional R construction at high speeds, which increases the cost of parts used and makes it susceptible to disturbance noise. However, according to the present invention, such problems can be solved by switching the number of step settings, and it is possible to provide a stepping motor drive device that is resistant to disturbance noise without increasing costs. can. Further, according to the present invention, there is an advantage that, for example, the feed pitch of a ball screw or the like can be easily changed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of the configuration of essential parts of a stepping motor drive device according to the present invention, FIG. 2 is a block diagram showing a schematic configuration of an example of the stepping motor drive device according to the present invention, and FIG. FIG. 4 is a waveform diagram showing the relationship between the address and the excitation current value setting signal, and FIG. 5 is a waveform diagram showing the excitation current of each phase. DESCRIPTION OF SYMBOLS 1... First adder/subtractor, 2... Stepping motor, 3... Discriminator, 4... Second adder/subtractor, 5...
Selection circuit, 6... Latch circuit, 8... Delay circuit, 9
. . . Phase switching signal output circuit, 71 . . . Address calculation circuit, 16.17 . . . 1st. Second excitation current value setting signal forming circuit, 18...stepping motor drive unit. 1st plan 111, ------□ Figure 2

Claims (1)

[Scope of Claims] Forward and reverse rotation direction input signals and how many division steps are taken by dividing the basic step angle of the stepping motor into 1/M (where M is the number of divisions of the basic step angle). When input signals include a step number setting signal N (however, N is a positive integer) and a current position signal P indicating the current step position, when the rotation direction input signal is a forward rotation signal, P+N=K. a first adder/subtractor that adds and subtracts P-N=K when the rotational direction input signal is a reverse rotation signal and outputs an output signal K; K≧M or K≦0 using the division number setting signal M as an input signal
a discriminator that discriminates between the above, and the output signal K, the division number setting signal M, and the rotation direction input signal as input signals, and when the rotation direction input signal is a normal rotation signal, (P+N)-M; = Y, and a second adder/subtractor that adds and subtracts (P-N) + M = Y when it is a reverse signal and outputs an output signal Y; K
≧M or K≦0 as an input signal, if the above K≧M in the forward rotation state, the above output signal Y=(P+N)−M is output as the output signal Z, and the above If K≧M, the output signal K=P+N is output as the output signal Z, and if K≦0 in the reverse state, the output signal Y=(P−N)+M is output as the output signal Z, and the reverse rotation occurs. If K≦0 in the state, output signal K=P as output signal Z
a selection circuit that selects and outputs -N; a latch circuit that latches the output signal Z of the selection circuit at the rising edge every time a step command pulse is applied and outputs the output signal Z as an address signal AD; a delay circuit that delays the address signal AD by a time width wider than the pulse width of the step command pulse and outputs it as the current position signal P;
The above K≧M or the K
a phase switching signal output circuit that outputs the step command pulse as a phase switching signal when ≦0; and a phase switching signal output circuit that stores the pattern of the excitation current value setting signal of the stepping motor and outputs the step every time the address signal is input. an excitation current value setting signal forming circuit that sequentially outputs an excitation current value setting signal in a predetermined pattern; and an excitation current that excites the stepping motor using the excitation current value setting signal from the excitation current value setting signal forming circuit as an input signal. and a stepping motor drive unit that switches these excitation currents based on the phase switching signal and applies them to excitation windings of predetermined phases of the stepping motor.