JP3387298B2 - Magnetic pole position detector - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic pole position detecting device for detecting the magnetic pole position of an AC servomotor.

[0002]

2. Description of the Related Art Generally, a driver of an AC servomotor detects a magnetic pole position of a motor, that is, a rotation angle of a magnet of a rotor, and supplies a current according to the detected magnetic pole position to each armature winding of the motor. is doing. Here, a method of detecting a magnetic pole position in a conventional AC servo motor will be described with reference to FIG.
And it demonstrates with reference to FIG. FIG. 3 is a block diagram showing a configuration example of a conventional magnetic pole position detection device. In the figure, reference numeral 20 denotes a three-phase synchronous motor, and a U-phase winding 20u, a V-phase winding 20v, a W-phase winding 20 is fed from a driver (not shown).
The U-phase current Iu, the V-phase current Iv, and the W-phase current Iw are supplied to w, respectively, whereby the rotor 20a rotates. Here, the phase currents Iu, Iv, and Iw are sinusoidal currents, one cycle of each phase current corresponds to one rotation of the three-phase synchronous motor 20, and the phases of the phase currents are mutually different. It is offset by 120 °.

Reference numeral 21 is a pulse encoder integrally provided with the three-phase synchronous motor 20. The pulse encoder 21 has a magnetic pole position θ of the rotor 20a, that is, an angle between the U-phase winding 20u and the N pole of the magnet of the rotor 20a. In response, various pulse signals shown in FIG. 4 are output to the angle data output unit 25 provided on the driver side (not shown). The contents of various pulse signals shown in FIG.
It is as follows.

A-phase pulse: 1,000 to 2,000 pulses are output for each equal rotation angle during one rotation of the rotor 20a. Here, it is assumed that, for example, 1,000 pulses are output during one rotation of the rotor 20a. B-phase pulse: Similar to the A-phase pulse, 1,000 pulses are output at each equal rotation angle while the rotor 20a makes one rotation, but they are deviated by 90 ° from the phase of the A-phase pulse. Z-phase pulse: One pulse is output every time the magnetic pole position θ of the rotor 20a becomes 0 °. The Z-phase pulse is output in synchronization with the A-phase pulse, and its pulse width corresponds to one cycle of the A-phase pulse. U-phase pulse: Each time the magnetic pole position θ of the rotor 20a rotates by 180 °, it changes alternately to a high level and a low level, and the pulse rises when the magnetic pole position θ is 0 °. Also,
The cycle of the U-phase current Iu matches the cycle of the U-phase pulse. V-phase pulse: A pulse similar to the U-phase pulse, but U
It is 120 ° out of phase with the phase pulse. The cycle of the V-phase current Iv matches the cycle of the V-phase pulse. W-phase pulse: A pulse similar to the U-phase pulse and the V-phase pulse, but with a phase shift of 240 ° from the U-phase pulse and a phase shift of 120 ° from the V-phase pulse. The cycle of the W-phase current Iw matches the cycle of the W-phase pulse.

Reference numeral 25 denotes an angle data output section provided on the driver side (not shown), which outputs the angle data θd corresponding to the magnetic pole position θ based on various pulses output from the pulse encoder 21 through the six wires. Output to driver. The driver also supplies the phase currents Iu, Iv, Iw to the respective phase windings 20u, 20v, 20w of the three-phase synchronous motor 20 based on the angle data θd. Reference numeral 26 is a direction discriminator, which outputs the A-phase pulse as an up-count pulse UP when the A-phase pulse output from the pulse encoder 21 leads the B-phase pulse by 90 °, and the A-phase pulse is the B-phase pulse. If it is delayed by 90 ° from the pulse, the phase A pulse is output as the down count pulse DOWN.

An initial magnetic pole position detector 27 estimates the magnetic pole position θ at the time of starting the AC servomotor from the U, V and W phase pulses output from the pulse encoder 21 at the time of starting the AC servomotor, and initializes it. The angle data θs is set in the up / down counter 28. The up / down counter 28 outputs the up count pulse UP or the down count pulse DO output from the direction discriminator 26.
It counts up or down according to WN and outputs the count value to the driver (not shown) as angle data θd. Further, the count value is cleared (count value = 0) by the Z-phase pulse.

Next, the operation of the above magnetic pole position detecting device will be described. First, when the AC servomotor is activated, the initial magnetic pole position detection unit 27 causes the pulse encoder 21
The U, V, and W phase pulses output from are regarded as absolute data of the magnetic pole position θ, and the initial angle data θs is estimated based on the absolute data. That is, in FIG. 4, the U-phase pulse is the first bit (least significant bit), the V-phase pulse is the second bit, and the W-phase pulse is the third bit (most significant bit). "0" at low level
If the input data is “101” (5), the magnetic pole position θ is 0 ° ≦ θ <60 °, and the data is “00”.
1 ”(1), 60 ° ≦ θ <120 °, and if the data is“ 011 ”(3), 120 ° ≦ θ <180 °,
If the data is “010” (2), 180 ° ≦ θ <2
40 °, if the data is “110” (6), 240 ° ≦ θ <300 °, if the data is “100” (4),
Assuming that the angle is in the range of 300 ° ≦ θ <360 °, the intermediate angle of the angle range indicated by each data is output to the up / down counter 28 as the initial angle data θs.

For example, when the magnetic pole position θ is 20 ° at the time of starting the AC servo motor, a U-phase pulse, V
The data of the phase pulse and the W-phase pulse is “101”, so that the initial magnetic pole position detection unit 27 sets 0 ° to 60 °.
Data corresponding to 30 °, which is an intermediate angle of °, is set in the up / down counter 28 as initial angle data θs. The direction discriminator 26 also advances or delays the phase of the A-phase pulse with respect to the phase of the B-phase pulse, thereby increasing or decreasing the up-count pulse UP or the down-count pulse DOWN.
Is output to the up / down counter 28.

As a result, the up / down counter 28
Sets the initial angle data θs according to the up count pulse UP or the down count pulse DOWN
Count up or down by 1 and angle data θd
Is output to a driver (not shown). As a result, the driver adjusts the three-phase synchronous motor 20 according to the angle data θd.
The phase windings 20u, 20v, and 20w are supplied with sinusoidal currents whose phases are shifted by 120 °.

When the magnetic pole position θ of the rotor 20a eventually becomes 0 °, the pulse encoder 21 outputs one Z-phase pulse, whereby the count value of the up / down counter 28 is cleared. Thereafter, the up / down counter 28 counts according to the up or down count pulse output from the direction discriminator 26,
When the Z-phase pulse is output, the operation of clearing the count value is repeated.

As described above, in the magnetic pole position detecting device described above, the magnetic pole position at the time of starting is estimated by the U, V, and W phase pulses, and the magnetic pole position is incremented or decremented by 1 to generate the angle data θd. After the first Z-phase pulse is output, the clearing of the count value by the Z-phase pulse and the counting according to the up or down count pulse are alternately performed to generate the angle data θd.

[0012]

By the way, in the above-mentioned magnetic pole position detecting device, since six kinds of pulse signals are used for detecting the magnetic pole position, the number of wires between the driver and the motor is large, and the wiring cable is large. There was a problem that it would increase the cost of the connector. Further, since the outer diameter of the wiring cable becomes large, there is a problem that it is difficult to handle. In order to solve this drawback, conventionally, modems are provided on the driver side and the motor side, respectively, and U, V,
The W-phase pulse is converted into serial data and transmitted from the pulse encoder to the magnetic pole position detection unit.

That is, 3 for A phase, B phase, and Z phase pulses are provided between the pulse encoder 21 and the angle data output section 25.
First, the wiring of the book is provided, and at the time of starting the AC servo motor, the U, V, and W phase pulses are treated as parallel data, and the motor side modem converts this into serial data, and the wiring for the output of the Z phase pulse is made. Send using. And
The modem on the driver side converts the received serial data into parallel data again and outputs it to the initial magnetic pole position detection unit 27, whereby the initial magnetic pole position detection unit 27 determines the initial angle based on the input parallel data. The data θs is set in the up / down counter 28.

Thereafter, the modem on the motor side outputs the Z-phase pulse to the wiring for outputting the Z-phase pulse, and the up / down counter 28 outputs the set initial angle data θs.
According to the up or down count pulse output from the direction discriminator 26, the up or down count is performed one by one, and after the first Z phase pulse is output, the angle data θd is output based on the A, B, and Z phase pulses. . However, in the case of this method, although the number of wires can be reduced, the standard modem IC cannot be used and a special modem IC is required, so that there is a drawback that the cost is further increased.

The present invention has been made in view of such circumstances, and provides a magnetic pole position detecting device having a simple and inexpensive structure, which can reduce the number of wires between the motor side and the driver side. The purpose is to do.

[0016]

SUMMARY OF THE INVENTION The first aspect of the present invention, a first plurality of pulse signals that correspond to the magnetic pole position of the rotor of the synchronous motor, an output each time the rotor rotates by a predetermined angle Pulse signal generating means for respectively generating the second plurality of pulse signals, and initial magnetic pole position estimating means for estimating the magnetic pole position of the rotor immediately after the synchronous motor is started by the first plurality of pulse signals. And a magnetic pole position composed of the magnetic pole position estimated by the initial magnetic pole position estimating means and angle data output means for outputting data according to the rotation angle of the rotor based on the second plurality of pulse signals. In the detection device, the first and second plurality of pulse signals are sequentially output from a common output terminal, and digital data having a predetermined value is generated before outputting each of the plurality of pulse signals. Border A pulse output control means for <br/> force output from the output terminal as a signal, the identifying the value of the digital data, a plurality of pulse signals subsequently input to the digital data is first input, the first Output to the initial magnetic pole position estimating means as a plurality of pulse signals of
An input pulse control means for outputting to the angle data output means a plurality of pulse signals continuously input to the next input digital data as the second pulse signals, and a value of the digital data. Is the first
When the multiple pulse signals of are regarded as digital data,
The magnetic pole position detecting device is characterized in that the digital data has an unacceptable value .

According to a second aspect of the present invention, in the magnetic pole position detecting device according to the first aspect, the pulse output control means includes data generating means for generating the digital data,
Any one of the first plurality of pulse signals output from the pulse signal generating means, the second plurality of pulse signals, and the digital data output from the data generating means is selected and output to the output terminal . And a selection control means for controlling a signal selected by the selection means. The selection control means first selects the digital data after the selection means starts the synchronous motor. Then, the selection means is controlled so as to select the first plurality of pulses, and further, the digital data is selected again, and then the second plurality of pulses is selected.

According to a third aspect of the present invention, in the magnetic pole position detecting device according to the first or second aspect, when the value of the digital data is such that the first plurality of pulse signals are regarded as digital data, The digital data has a value that cannot be taken.

[0019]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a magnetic pole position detection device for an AC servomotor according to an embodiment of the present invention. In this figure, parts corresponding to those in FIG. 3 are assigned the same reference numerals and explanations thereof are omitted. The magnetic pole position detection device shown in FIG.
Differences from the above are as follows.

Reference numeral 1 denotes a selection control section (pulse output control means), which is a 3-bit digital data Q at a predetermined timing.
A, QB, QZ (digital data having a predetermined value) are output, and the digital data QA, QB, Q
Z, U, V and W phase pulses (first plural pulse signals) output from the pulse encoder 21 (pulse signal generating means) or A, B and Z phase pulses (second plural pulse signals) The selection signals S1 and S2 for selecting either of the above are output. Here, the above-mentioned digital data QA, QB,
QZ is, so to speak, a boundary signal that is output from when the AC servomotor is powered on until it is completely started up and before outputting various pulse signals to the angle data output unit 10, and is either 0 or 7. Takes the value of.

Reference numerals 2a to 2c are 3-input 1-output selectors (pulse output control means), which are input to the input terminals D1, D2, D3 in accordance with the selection signals S1, S2 output from the selection control section 1, respectively. Any one of the signals is output from the output terminal Q to the angle data output unit 10 provided on the driver side. Here, to the input terminals D1, D2, D3 of the selector 2a, the A-phase pulse and the U-phase pulse output from the pulse encoder 21 and the first (least significant) digital data output from the selection control unit 1 are sequentially arranged. Bits QA are input respectively.

The input terminals D1 and D of the selector 2b
The B-phase pulse output from the pulse encoder 21, the V-phase pulse, and the second bit QB of the digital data output from the selection control unit 1 are sequentially input to 2 and D3. Also, the input terminals D1 and D of the selector 2c
The Z-phase pulse output from the pulse encoder 21, the V-phase pulse, and the third (most significant) bit QZ of the digital data output from the selection control unit 1 are sequentially input to 2 and D3.

When the selection signals S1 and S2 output from the selection control unit 1 are both "0", the selectors 2a to 2c output the signal input to the input terminal D1 as "1",
When S2 is "0", the signal input to the input terminal D2 is
When S1 is "0" and S2 is "1", the signal input to the input terminal D3 is output from each output terminal Q. Three
Is a reset circuit, which outputs one pulse signal (reset pulse) to the selection control unit 1 when the AC servomotor is powered on. Here, the selection control unit 1, the selectors 2a to 2c, and the reset circuit 3 described above are provided on the motor side together with the pulse encoder 21.

Similar to the angle data output unit 25 shown in FIG. 3, the angle data output unit 10 is provided on the driver side, and based on various signals output from the motor side, magnetic poles of a three-phase synchronous motor (not shown). The angle data θd corresponding to the position is output to the driver. Reference numeral 11 is a data detection unit (input pulse control means), and each pulse signal output from the selectors 2a to 2c is 3-bit digital data (the output of the selector 2a is the least significant bit, the output of the selector 2c is the most significant bit). The pulse signals output from the selectors 2a to 2c according to the input digital data are output to the initial magnetic pole position detector 27 or the direction discriminator 26 and the up / down counter 28 as appropriate.

In the detection of the boundary signal described above, for example, a 3-input AND gate is used to output a high level signal when the value of the boundary signal is 7, and a 3-input NOR gate is used to output the boundary signal. When the value of is 0, it can be realized by outputting a high level signal. Also,
The direction discriminator 26 and the up / down of various pulses output from the selectors 2a to 2c from the initial magnetic pole position detector 27.
To switch to the down counter 28, for example, input 3-bit digital data is input to the initial magnetic pole position detection unit 2
7 or a selector that outputs to either the direction discriminator 26 or the up / down counter 28 is prepared, and a gate for continuously maintaining an open state is provided by the high level signal output from the above-mentioned 3-input AND. A method is conceivable in which a counter is provided to count the output of the NOR gate of three inputs that has passed through this gate and the count value is used as the select signal of the selector.

The operation of the magnetic pole position detecting device described above will be described below with reference to FIGS. 1 and 2. Figure 2
It is a figure which shows the state of each pulse signal output from selectors 2a-2c, and the content of operation of the selection control part 1 and the data detection part 11 in each state of each pulse signal. In this figure, (a) shows a pulse signal output from the selector 2a, (b) shows a pulse signal output from the selector 2b, (c) shows a pulse signal output from the selector 2c, and (d) shows selection. The operation content of the control unit 1 and (d) show the operation content of the data detection unit 11.

First, when the power source of the AC servomotor is turned on, each part of the angle data output section 10 is reset on the driver side, and a reset pulse is output from the reset circuit 3 on the motor side to select the control section. 1
Is reset. When the reset of the selection control unit 1 is completed, the selection control unit 1 first outputs the boundary signal having a value of 7 for a predetermined time t1. That is, all the bits QA, QB, QZ of the digital data are output as "1", and the selection signals S1, S2 are respectively set as "0".
Outputs "1". Here, the predetermined time t1 is a time in which the data angle output unit 10 can completely complete the reset operation.

From the output terminals Q of the selectors 2a to 2c, the digital data QA output by the selection control unit 1
When QB and QZ are output and the reset operation is completed in the data angle output unit 10, the data detection unit 11
It is detected that the input digital data is "7". As a result, the data detection unit 11 recognizes that the AC servomotor is immediately after the power is turned on (initial state),
No signal is output to the direction discriminator 26, the initial magnetic pole position detector 27, and the up / down counter 28. Then, when the predetermined time t1 has elapsed, the selection control unit 1
Outputs a boundary signal having a value of 0 for a predetermined time t2. That is, the selection signals S1 and S2 are each "0".
Each bit Q of digital data while outputting "1"
"0" is output for all of A, QB and QZ. Here, the predetermined time t2 is a time in which the data detection unit 11 can sufficiently recognize the value of the boundary signal.

As a result, the data detection unit 11 determines that the value of the boundary signal input last time is "7" and the value of the boundary signal input this time is "0", so that the U, V, W phase pulse Enter the input waiting state. That is, when the input data is not "0" from the current state, it is changed to U, V,
The pulse is determined to be a W-phase pulse and is output to the initial magnetic pole position detection unit 27. Then, when the predetermined time t2 has elapsed, the selection control unit 1 sets the selection signal S1 to "1" and S2 to "0", and outputs the U, V, and W phase pulses output from the pulse encoder 21 to the data detection unit. Output to 11.

The data detector 11 receives the input U, V,
The W-phase pulse is output to the initial magnetic pole position detection unit 27, and the initial magnetic pole position detection unit 27 estimates the magnetic pole position immediately after starting from the input U, V, and W-phase pulses, and the up / down counter 28 receives the initial angle. Set the data θs. Next, in the selection control unit 1, a time t3 that is expected until the initial angle data θs is set in the up / down counter 28.
Then, the selection control unit 1 outputs "0" (that is, the digital data value is "0") for all bits QA, QB, and QZ of the digital data, and the selection signal S
1 and S2, "0" and "1" are output for a time t4 at which the data detection unit 11 can sufficiently recognize the value of the boundary signal.

Then, the data detecting section 11 detects that the value of the boundary signal is "0", and the value of the boundary signal input last time is "0". Therefore, the U, V, W phase pulse is detected. It recognizes that the output of is finished and enters the waiting state for the input of the A, B and Z phase pulses. That is, at the time t after the boundary signal output after the U, V, and W phase pulses are input.
The pulse signal inputted after the lapse of 4 times is judged as the A, B and Z phase pulses, and the A and B phase pulses are outputted to the direction discriminator 26 and the Z phase pulse to the up / down counter 28. Then, when the predetermined time t4 has elapsed from the above-mentioned state, the selection control unit 1 sets both the selection signals S1 and S2 to "0",
The A, B, and Z phase pulses output from the pulse encoder 21 are output to the data detection unit 11.

As a result, the data detector 11 outputs the input A, B phase pulse and Z phase pulse to the direction discriminator 26 and the up / down counter 28, respectively, and the direction discriminator 26 receives the input. Depending on the lead or lag of the phase of the A phase pulse with respect to the phase of the generated B phase pulse,
Up count pulse UP to up / down counter 28
Alternatively, the down count pulse DOWN is output. Further, the up / down counter 28 counts up or down the set initial angle data θs one by one according to the input count pulse. After the first Z-phase pulse is output, the clearing of the count value by the Z-phase pulse and the counting according to the up or down count pulse are alternately performed to generate the angle data θd.

As described above, in the magnetic pole position detector of this embodiment, when the U, V, and W phase pulses are regarded as digital data, the data cannot take values (0 and 7).
Since the pulse signal is used as a boundary signal and various pulse signals are discriminated based on this, wiring for various pulse signals can be shared without performing serial-parallel conversion, and the number of wirings can be reduced by a simple and inexpensive configuration. You can

In this embodiment, of the boundary signals,
The value of the boundary signal indicating the initial state of the AC servo motor is 7,
Although the value of the boundary signal output before outputting the various pulse signals is 0, the values of the boundary signals, 0 and 7, may be interchanged. Also, between the boundary signal indicating the initial state of the AC servo motor and the boundary signal output before the next U, V, W phase pulse is output, the disconnection of the wiring between the driver and the motor from the selection control unit 1. It is also possible to output a signal for checking. Further, the reset pulse output to the selection control unit 1 may be output from the outside, for example, the driver side, regardless of the reset circuit 3.

[0035]

As described above, according to the first and second aspects.
According to the invention described in (1), the first and second plurality of pulse signals are sequentially output using a common wiring, and digital data having a predetermined value is output before each of the plurality of pulse signals is output. And a pulse output control means for generating and outputting the digital data, and a plurality of pulse signals that are subsequently input to the first input digital data are identified as the first plurality of pulse signals. A plurality of pulse signals that are output to the initial magnetic pole position estimating means and that are subsequently input to the digital data that is input next are output to the second
Since the input pulse control means for outputting the pulse signal to the angle data output means is provided, the wiring for outputting various signals can be shared, and the number of wirings between the motor side and the driver side can be reduced. can do.

According to the third aspect of the invention, the value of the digital data is a value that cannot be taken by the digital data when the first plurality of pulse signals are regarded as digital data. The number of wires between the motor side and the driver side can be reduced by a simple and inexpensive configuration without performing serial-parallel conversion or data communication using a special protocol.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a magnetic pole position detection device according to an embodiment of the present invention.

FIG. 2 shows states of various pulse signals output from the motor side to the driver side in the magnetic pole position detection device, and
FIG. 4 is an explanatory diagram for explaining operation contents of the selection control unit 1 and the data detection unit 11.

FIG. 3 is a block diagram showing a configuration example of a conventional magnetic pole position detection device.

FIG. 4 is an explanatory diagram for explaining various pulse signals output from a pulse encoder of the magnetic pole position detection device.

[Explanation of symbols]

1 ... Selection control unit, 2a, 2b, 2c ... Selector, 3
...... Reset circuit, 10, 25 …… Angle data output section,
11 ... Data detection unit, 21 ... Pulse encoder, 2
6 ... Direction discriminator, 27 ... Initial magnetic pole position detector, 28
…… Up / down counter.

─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-5-157581 (JP, A) JP-A-4-21098 (JP, A) JP-A-5-79856 (JP, A) JP-A-6- 203285 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01B 7/30 101 G01D 5/245 101 G08C 15/06

Claims (2)

(57) [Claims] 1. A first plurality of pulse signals corresponding to magnetic pole positions of a rotor of a synchronous motor, and a second plurality of pulse signals output each time the rotor rotates a predetermined angle are generated. Pulse signal generating means, initial magnetic pole position estimating means for estimating the magnetic pole position of the rotor immediately after starting the synchronous motor by the first plurality of pulse signals, and magnetic pole position estimated by the initial magnetic pole position estimating means. An angle data output means for outputting data according to a rotation angle of the rotor based on the second plurality of pulse signals, and a magnetic pole position detecting device comprising: Output pulse signals in sequence
The digital data having a predetermined value is generated before being output from the terminal and before outputting each of the plurality of pulse signals.
A pulse output control means for outputting from the output terminal as a boundary signal, a value of the digital data is identified, and a plurality of pulse signals continuously input to the first input digital data are output as the first plurality of pulses. Input pulse control means for outputting to the angle data output means a plurality of pulse signals that are output as signals to the initial magnetic pole position estimation means and that are subsequently input to the digital data that has been input next time as the second pulse signals. it comprises a preparative, the value of the digital data, said first plurality of pulses Shin
If you consider an issue to be digital data,
The magnetic pole position detection device is characterized in that it is a value that cannot be taken . 2. The pulse output control means includes a data generating means for generating the digital data, a first plurality of pulse signals output from the pulse signal generating means, a second plurality of pulse signals, and data generation. The selection means for selecting any one of the digital data output from the means and outputting it to the output terminal ; and the selection control means for controlling the signal selected by the selection means. The control means controls the selection means such that the selection means first selects the digital data and then selects the first plurality of pulses after the synchronous motor is activated, and then again the digital data is selected again. 2. The magnetic pole position detecting device according to claim 1, wherein the magnetic pole position detecting device is controlled so as to select and then select the second plurality of pulses.