JPH0625937B2 - Positioning control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention counts pulse signals of a pulse generator attached to a controlled shaft and stops the controlled shaft at an arbitrary position based on the count value. The present invention relates to a positioning control device.

[Conventional technology]

A conventional positioning control device of this type is shown in FIG. This is a so-called orientation in which the spindle etc. of the machine tool is stopped at a predetermined angular position, and the motor (1) is controlled by the motor speed control device (2). I'm running. A pulse generator for motor speed control (hereinafter referred to as PLG for speed control) that generates two types of sine wave signals with a constant phase difference from each other in the motor (1) at a frequency according to the rotation speed (3) Are coupled, and the signal is applied to the motor speed control device (2), the motor rotation direction determination circuit (4), and the frequency-voltage converter (9) described later. Of these, the motor rotation direction determination circuit (4)
Determines the rotation direction of the motor (1) based on the output signal of the speed control PLG (4), and outputs a level "1" signal in the case of normal rotation. Further, if the command for rotating the motor (1) at the normal speed N ₁ is the normal speed command, a positive voltage corresponding to a slower orientation speed N ₂ , that is, an orientation speed command voltage for outputting the orientation speed command. Generator (5)
Is provided on the output side of the motor rotation direction determination circuit.
An orientation speed command voltage polarity determination circuit (6) is provided which outputs the output voltage as it is according to the output signal level of (4) or inverts it to a negative voltage and outputs it.
Furthermore, the creep speed N ₃ slower than the orientation speed N ₂
Corresponding to the positive voltage, that is, a creep speed command voltage generator (7) that outputs a creep speed command is provided, and its output side corresponds to the output signal level of the motor rotation direction determination circuit (4). A creep speed command voltage polarity determination circuit (8) that outputs the output voltage as it is or inverts it to a negative voltage and outputs it is provided.

On the other hand, the frequency-voltage converter (hereinafter referred to as F / V converter) (9) to which the sine wave signal of the speed control PLG (3) is added outputs a voltage commensurate with the frequency of the sine wave. The side is provided with a speed feed back polarity determination circuit (10) that outputs the output voltage as it is, corresponding to the output signal level of the motor rotation direction determination circuit (4), or inverts it to a negative voltage and outputs it. The output is the speed coincidence determination circuit (1
Added to 1). This speed coincidence determination circuit (11) compares the output of the above-mentioned orientation speed command voltage polarity determination circuit (6) with the output of the speed feed back polarity determination circuit (10),
When the two coincide with each other, a signal of level "1" is output.

Next, on the input side of the motor speed control device (2), the normal speed command, the orientation speed command obtained via the orientation speed command voltage polarity determination circuit (6), the creep speed command voltage polarity determination circuit (8) Creep speed command, obtained via
Also, switches (12) to (15) for inputting a speed command obtained via a digital-analog converter (28) described later are provided, and the sequence counter (16) is one of these switches. To close.

On the other hand, the output shaft of the motor (1) is connected to a final shaft (18) as a controlled shaft via a power transmission means (17) such as a gear or a belt, and the final shaft (18) is connected to the final shaft (18). Is N at a specific position during one rotation with N A-phase pulses and N B-phase pulses having a constant phase difference during one rotation.
A position detecting pulse generator (hereinafter referred to as position detecting PLG) (19) for generating C-phase pulses is attached.
The A-phase pulse and the B-phase pulse of the position detecting PLG (19) are compared in phase by the pulse generator rotation direction discrimination circuit (20), and when the A-phase pulse leads the B-phase pulse, the level is "1". Signal is output, and at the opposite of this, a signal of level "0" is output. The frequencies of the A-phase pulse and the B-phase pulse are multiplied by 4 by the quadrupling circuit (21). And the pulse generator rotation direction discrimination circuit (20)
The output of is added to the terminal U / D that determines the count-up and countdown of the counter circuit (22), and the quadruple multiplication circuit (21)
Are applied to the signal input terminals CL of this counter circuit. External stop position data (23) is added to the preset value input terminal P of the counter circuit (22), and the sequence counter (16) is added to the preset terminal PR.
Is adding a signal.

Next, the output of the first position loop gain setter (24) that outputs the digital position loop gain and the count value of the counter circuit (22) are input, and the counter circuit (22) is input.
Position loop gain comparison circuit (25) which gives a signal of level "1" to the sequence counter (16) when the difference between the output of the control signal and the final stop position becomes smaller than the value of the first position loop gain setting device (24) Is provided. Also, like this,
The output of the second position loop gain setter (26) that outputs the digital position loop gain by setting, and the counter circuit
Input the count value of (22) and the difference between the output of the counter circuit (22) and the final stop position is the second position loop gain setter (2
A second position loop gain comparison circuit (27) for providing a signal of level "1" to the sequence counter (16) when it becomes smaller than the value of 6) is provided.

Further, the count value of the counter circuit (22) is converted into an analog signal by a digital-analog converter (hereinafter referred to as a D / A converter) (28), and this is converted into a motor speed via a switch (15) as a speed command. It is designed to be added to the control unit (2). Furthermore, a fixed position stop command for the final axis (18) is also added to the sequence counter (16).

Next, the operation will be described. When the constant position stop command is not applied, the sequence counter (16) closes the switch (12) and opens the other switches (13) to (15), so the motor speed controller (2) uses the normal speed command. The motor (1) is rotated at a speed N ₁ commensurate with. Here, the motor (1), the belt (17a) as the power transmission means, the final shaft (18) and the position detecting PLG (19) are in the relationship shown in FIG. It is assumed that the detection PLG (19) rotates in the same direction.

Now, when a positive speed command voltage is applied, the motor speed control device (2) rotates the motor (1) to the forward rotation side, so that the speed control PLG (3) also rotates in the forward rotation direction, and FIG. As shown in (2), the A phase outputs two types of sine wave signals that are ahead of the B phase. When this relationship exists, the motor rotation direction determination circuit
(4) outputs the signal of level "1", and the F / V converter (9)
Outputs a voltage commensurate with the frequency of these sinusoidal signals. Further, since the motor rotation direction determination circuit (4) outputs a signal of level "1", the orientation speed command voltage polarity determination circuit (6), the creep speed command voltage polarity determination circuit (8) and the speed feedback back polarity determination circuit (Ten)
Outputs the input positive voltage as it is.

Further, when the motor (1) rotates in the forward rotation direction, the position detection PLG (19) also rotates in the forward rotation direction, and as shown in FIG. The B-phase pulse and the C-phase pulse that becomes the "1" level for a short time at a specific position during one rotation are output. At this time, the pulse generator rotation direction discrimination circuit (20) sees the relationship between the A-phase pulse and the B-phase pulse and outputs a signal of level "0" to the U / of the counter circuit (22).
In addition to the D terminal, the quadruple multiplication circuit (21) detects the rising and falling edges of the A-phase pulse and the B-phase pulse, respectively, and applies the quadrupled count pulse as shown in FIG. 4 to the signal input terminal CL. .

Here, when the fixed position stop command is applied, the sequence counter (16) opens the switch (12) and closes the switch (13). At this time, the motor rotation direction determination circuit (4) outputs a signal of level "1", and the orientation speed command voltage of the orientation speed command voltage generator (5) is determined by the orientation speed command voltage polarity determination circuit (6). Even if it passes through, it is directly added to the motor speed control device (2). Accordingly, the motor speed control device (2) decelerates the motor (1) from the normal speed N ₁ to the orientation speed N ₂ . Further, in this case, the speed matching control circuit (11) compares the output level of the orientation speed command voltage polarity determination circuit (6) with the output level of the speed feedback back voltage polarity determination circuit (10), and when both match. That is, when the motor (1) reaches the orientation speed, the level "1" signal is output. Sequence counter
When (16) receives this level "1" signal and the C-phase pulse of the position detecting PLG (19) rises, the contents are advanced by one step and the counter circuit (22) is preset. Therefore, the counter circuit (22) uses the external stop position data (2
The value obtained by adding 3) to the final stop position is output, and the pulse generator rotation direction discrimination circuit (20) adds a signal of level "0", so it is set to the countdown side. Start the countdown with the count pulse of (21).

On the other hand, the first position loop gain comparison circuit (25) looks at the difference between the count value of the counter circuit (22) and the final stop position, and the difference is more than the value of the first position loop gain setter (24). When becomes smaller, the level "1" signal is output. When the sequence counter (16) receives this level "1" signal, it advances the contents by one step and closes the switch (14) instead of opening the switch (13). At this time, the motor rotation direction determination circuit (4) outputs a signal of level "1", and the creep speed command voltage of the creep speed command voltage generator (7) is determined by the creep speed command voltage polarity determination circuit (8). Even if it passes through, it is directly added to the motor speed control device (2). Therefore, the motor speed controller (2) decelerates the motor (1) from the orientation speed N ₂ to the creep speed N ₃ .

As a result, the rotating motor (1) is the normal speed N _1, as shown in FIG. 5, when the fixed-position stop command is applied at time t ₁ is decelerated from the normal speed N ₁ to Orientation speed N _2, When the creep speed command is added at time t ₂ , the speed is reduced from the orientation speed N ₂ to the creep speed N ₃ .

Next, the second position loop gain comparison circuit (27) looks at the difference between the count value of the counter circuit (22) and the final stop position, and the difference is the value of the second position loop gain setter (26). When it becomes smaller than that, a signal of level "1" is output. When the sequence counter (16) receives this level "1" signal, it advances the content by one step and closes the switch (15) instead of opening the switch (14). At this time, the count value of the counter circuit (22) is converted into an analog voltage signal by the D / A converter (28) and the motor speed control device (2)
Added to.

Since this D / A converter (28) is used in bipolar operation, the deviation between the final stop position and the output of the counter circuit (22) is smaller than the value set in the second position loop gain setter (26). In the range, that is, in the range where the switch (15) is closed, a positive voltage is output when the counter circuit (22) counts down, and the voltage gradually decreases with each countdown, and becomes zero at the final stop position. In addition, a negative voltage is output when counting up, and the absolute value decreases with each counting up.
It is set to zero at the final stop position.

Thus, the motor speed control device (2) operates at time t _{3 in} FIG.
After that, rotate the motor (1) at a speed commensurate with the positive output voltage of the D / A converter (28), and stop the motor (1) at the final stop position where this output becomes zero. 1
Positioning 8) is performed.

On the other hand, when the negative voltage is applied to the normal speed command and the motor (1) is rotating in the reverse direction without the orientation command being applied, the B output from the speed control PLG (3) Since the phase signal waveform leads the A phase signal waveform, the motor rotation direction discrimination circuit (4) detects this relationship and outputs a signal of level "0". Therefore, each polarity determination circuit (6),
(8) and (10) output by changing the input voltage to negative. Further, the position detecting PLG (19) outputs a B-phase pulse and an A-phase pulse whose phase is ahead of this, and the pulse generator rotation direction discrimination circuit (20) outputs the A-phase pulse and the B-phase pulse. Depending on the relationship with the counter circuit (2
It is added to the U / D terminal of 2). Thus, the motor (1) can start the fixed position stop operation from the reverse rotation side in the same operation as the forward rotation side, stop at the final stop position, and stop the final axis (18) at the fixed position.

[Problems to be solved by the invention]

The conventional positioning control device is configured as described above, and performs the above operation as long as the motor (1) and the position detecting PLG (19) are connected in the state shown in FIG. 6 (a). However, since the motor (1) and the position detecting PLG (19) are connected to the opposite end of the final shaft as shown in FIG. 6 (b), both of them rotate in opposite directions, When the motor (1) rotates in the forward direction, the A-phase pulse leads the B-phase pulse in the position detection PLG (19). At this time, the pulse generator direction discriminating circuit (20) outputs a signal of level "1" in consideration of this relationship, and the counter circuit (22) starts counting up.
Therefore, when the switch (15) is closed due to the addition of the Orient command, the motor speed controller (2) is connected to the D / A converter.
The negative voltage of (28) is applied. At this time, the motor speed control device (2) tries to rotate the motor (1) to the reverse rotation side, so that the motor (1) eventually vibrates as shown by the broken line in FIG. 7.

Thus, in the conventional positioning control device, it is necessary to adopt a mounting structure in which the motor and the position detecting PLG always rotate in the same direction, which simplifies and downsizes the structure of the machine tool or the like. There was a problem of making it difficult.

The present invention has been made to solve the above problems, and a mounting structure in which the motor and the position detecting PLG rotate in the same direction or a mounting structure in which the motor and the position detecting PLG rotate in opposite directions can be arbitrarily selected. Accordingly, it is an object of the present invention to provide a positioning control device capable of realizing simplification and downsizing of the structure of a machine tool or the like.

[Means for solving problems]

A positioning control device according to the present invention includes a rotation direction discriminating circuit that outputs a signal whose level changes in two ways corresponding to the rotation direction of a pulse generator, and counts up and counts down the output signal level of this rotation direction discriminating circuit. As a switching condition, a condition selecting means for arbitrarily selecting and outputting either the input signal level as it is or the inversion is provided between the counter circuit and the counter circuit for counting the output pulse of the pulse generator.

[Action]

In the present invention, when the pulse generator is connected to the motor so as to rotate in the same direction and when the pulse generator is connected so as to rotate in the opposite direction, the rotation direction determination circuit of the rotation direction determination circuit is selected by the condition selection means. Since the output level is switched and applied to the counter circuit, the controlled axis can be fixedly stopped in the same manner even if the coupling state of the pulse generator changes.

〔Example〕

FIG. 1 is a block diagram showing the construction of an embodiment of the present invention, in which (1) to (28) are exactly the same as those of the conventional device. Other than these (29) is a condition setter that is composed of a switch, a resistor, etc., and outputs a level "0" signal when the switch is turned on and a level "1" signal when turned off, (30) Is a level inversion circuit that inverts the output signal level of the pulse generator rotation direction determination circuit (20) according to the output signal level of the condition setting device (29). The condition setter (29) and the level inverting circuit (30) correspond to the condition selecting means of the present invention.

The operation of the present embodiment configured as described above will be described below, particularly focusing on the differences from the conventional device.

First, assuming that the switch of the condition setter (29) is in the off state, the level inversion circuit (30) receives the signal of the level "1" of the condition setter (29), and determines the pulse generator rotation direction. The output signal level of the circuit (20) is output as it is. Therefore, the position detection pulse generator (19) is shown in FIG.
Condition setter (29) when mounted as shown in (a)
By turning off the switch, the fixed position can be stopped by the same operation as the conventional device.

Next, as shown in Fig. 6 (b), the position detecting pulse generator (19) is attached so as to rotate in the opposite direction to the motor (1), and the switch of the condition setter (29) is turned on. Assume that it is in the ON state.

Here, if the constant position stop command is input while the motor (1) is rotating in the forward rotation side, the motor (1) is rotated forward and decelerated to the creep speed. On the other hand, PLG for position detection (19)
Outputs a pulse of which the phase A leads the phase B, and the pulse generator direction discriminating circuit (20) outputs a signal of level "1" according to the phase relationship between them. However, since the level inversion circuit (30) is applied with the level “0” signal from the condition setter (29), the level generator 1 discriminating circuit (20) outputs the level “1” signal. Is changed to level "0" and added to the U / D terminal of the counter circuit (22).

Therefore, the counter circuit (22) starts counting down,
When the switch (15) is closed, the motor speed control device (2) displays the count value of the counter circuit (22) in the D / A converter (2
Since the analogized positive voltage is given by 8), the motor (1) can be decelerated as it is, and the final axis can be stopped at the fixed position at the final stop position.

Thus, according to this embodiment, the position detecting PLG (19) is coupled to the motor (1) so as to rotate in the same direction as shown in FIG. Figure (b)
Even if coupled to rotate in the opposite direction, as shown in
The final axis can be stopped at a fixed position by turning the switch of the condition setter (29) off and on.

In the above embodiment, the conditions of the counter circuit (22) for up-counting and down-counting are changed by changing the condition of the condition setter (29) depending on how the position detecting PLG (19) is attached. However, instead of this, even if a polarity determination circuit that can invert the output of the D / A converter (28) between positive and negative is provided by the condition setter (29), the fixed position stop control similar to that described above is possible. is there.

〔The invention's effect〕

As is clear from the above description, according to the present invention, the condition selecting means arbitrarily switches the output level of the rotation direction determining circuit to add the output level to the counter circuit. Whether the tool is connected to rotate in the same direction or to rotate in the opposite direction, the controlled axis can be fixedly stopped in the same manner. There is an effect that the structure can be simplified and made compact.

[Brief description of drawings]

FIG. 1 is a block diagram showing the construction of an embodiment of the present invention,
FIG. 2 is a block diagram showing the configuration of a conventional positioning control device, FIGS. 3 and 4 are waveform diagrams for explaining the operation of the device, and FIG. 5 is a diagram for explaining the operation of the device. Diagram showing the relationship between time and motor speed, Fig. 6 (a), (b)
Is a schematic configuration diagram showing a coupled state of main elements of the device, and FIG. 7 is a diagram showing a relationship between time and distance for explaining the operation of the device. (1): Motor, (2): Motor speed controller (17): Power transmission means (20): Pulse generator rotation direction discrimination circuit (22): Counter circuit, (29): Condition setter (30): Level inversion circuit In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] 1. A pulse generator, which is attached to a controlled shaft connected to a motor via a power transmission means, and which outputs two types of pulse signals having different phases according to the rotation of the controlled shaft, and Rotation direction discrimination that outputs a signal whose level changes in two ways corresponding to the rotation direction of the pulse generator by detecting the advance or delay of the phase between the two types of pulse signals output from the pulse generator. A circuit, a counter circuit that counts the output pulse of the pulse generator with the output signal level of the rotation direction determination circuit as a switching condition between the count up and the countdown, and an input provided between the counter circuit and the rotation direction determination circuit The count value of the counter circuit is provided with a condition selection means for arbitrarily selecting and outputting either the signal level as it is or inversion. Positioning control apparatus characterized by stopping the controlled axis to an arbitrary position by controlling the motor as degrees command. 2. The condition selecting means operates a switch to output different kinds of signals, and a condition setting device that outputs the rotation direction discriminating circuit in response to an output signal from the condition setting device. Alternatively, the positioning control apparatus according to claim 1, further comprising a level inversion circuit that selects one of the inversions and supplies the selected counter circuit with the level inversion circuit.