JPS62135291A - Changeover controller for ac servometer - Google Patents

Abstract

PURPOSE:To control AC servomotors with N-many shafts by one or number smaller than N (N represents the number of shafts of motors) by fitting a changeover and a relay for changeover and changing over a resolver-position detecting means or a motor excitation-phase generating means with time. CONSTITUTION:When a control signal X is set to an 'L' level, all of various elements of a resolver-position detector 4, a reference-wave counter 5, a reference-wave generator 6, a U-phase generator 7, a V-phase generator 8, a W-phase generator 9, a resolver excitation circuit 10, U-phase, V-phase and W-phase PWM circuits 11, 12 and 13 and transistor pairs 14, 15 and 16 for U phase, V phase and W phase control a servomotor 17A for an A shaft by the operation of a changer 19 and a relay 20 for changeover. When the control signal X is set to an 'H' level, on the other hand, said various elements inversely control a servomotor 17B for a B shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an AC servo motor control device, and more particularly to a multi-axis AC servo motor switching control device.

(Prior Art) First, with reference to FIG.
The principle of the prior art in an AC servo motor control device for a resolver will be explained. In FIG. 4, l is an operational amplifier, 2 is a PLL (phase low 2 loop) circuit, 3 is a digital counter, 4 is a resolver position detector composed of, for example, a subtracter, 5 is a reference wave counter, and 6 is a parenchyma. wave oscillator, 7, 8 and 9 are respectively a U-phase generator, a V-phase generator and a W-sum generator; 10 is a resolver excitation circuit; 11.1
2.13 is the PWM (pulse width modulation) times of the U phase, ■ phase, and W phase, respectively. 8.14.15.18 is ttzo VL
A pair of power transistors for U phase, ■ phase, and W phase, 17 is an AC servo motor, and 18 is a controlled resolver.

In such a resolver AC servo motor control device, the output signal from the rotor of the resolver 18 is fed back into the amplifier 1, and the output of the amplifier 1 is fed into the digital counter 3 via the PLL circuit 2. The output signal of the digital counter 3, for example A. -A 10 is an output signal B of the reference wave counter 5 that is input to the resolver position detector 4 and is also input to the resolver position detector 4. -8
compared to 10.

Output signals A0 to A10 of the digital counter 3 and output signal B of the reference wave counter 5. −B Ill difference signal CI
+ -C10 is a U-phase generator 7, a V-phase generator 8. It is input to each of the W sum generators 9. U phase generator 7, V phase generator 8
, W sum generator 9 output signals are respectively outputted from PWM circuits 11 .
12.13, PWM circuits 11, 12, +3 (
7) Output signal uI! : u, v and v, w and W control transistor pairs 14, 15, and 16, respectively. V+flllI of each transistor pair 14.15.18 is IC
V- is connected to the + side of the EC current (not shown) and the - side.

A rotor (not shown) of the AC servo motor 17 is disposed on the same axis as a rotor of the resolver 18 .

Furthermore, the A-phase stator and B-phase stator of the resolver 18 are D;(
They are arranged at a logical angle of 90'.

The oscillation output of the reference wave oscillator 6 is input to the digital counter 5, and a part of the output of the digital counter 5 is input to the resolver excitation circuit IO. The reference wave oscillator 6 finds a reference wave at 10.24 MHz, for example, and the oscillation reference wave is 21! It is input to the i quasi-wave counter 5.

The reference wave counter 5 is, for example, an 11-bit binary counter, and from its most significant bit output 810, 5
A KHz clock signal is output. This clock signal is input to the resolver excitation circuit 10, and from its A phase output, a sine wave signal rotated to the input clock signal is output, and a B
From the phase output, a sine wave signal with a phase shift of 90' from the A-phase sine wave signal is output and input to the two stators of the resolver 18, respectively, and the rotor of the resolver 18 receives the current signal of the rotor. A sine wave signal appears whose phase depends on the angle.

This sinusoidal signal appearing at the rotor of the resolver is transmitted to the amplifier 1
After being amplified by the PLL circuit 2, the resolver 18
The PLL circuit 2 operates so that the digital counter 3 outputs a signal that matches the phase detected in the above. Output signal AomA+o of digital counter 3 and reference wave counter 5
output signal B.

~ B Ill difference signal C8-010 is detected by the resolver position detector 4, and this difference signal C6-CtO represents the rotation angle of the rotor of the resolver, that is, the rotation angle of the rotor of the AC servo motor. . These difference signals C6
-C10 is the U-phase generator 7. V-phase generator8. W sum generator 9
A signal with a level suitable for each phase is generated and input to each phase's PWM circuit I+, 12.13.

The PWM circuits 11, 12, and 13 of each phase output a signal for the time required to turn on the transistor pair +4, 15, and 16 of each phase. For example, the PWM circuit 11 outputs a signal that turns on each transistor of the transistor pair 14. U, U are generated and applied to the base of the transistor. The output of each transistor pair 14, 15, 18 is the U phase of the servo motor,
It is connected to the windings of the (1) phase and W phase, respectively, and chopping power is efficiently applied to each of the windings.

On the other hand, a speed detector 31 is connected to the output of the amplifier l or the output of the resolver position detector 4, so that the rotational speed of the resolver can be detected.

(Problems to be Solved by the Invention) Conventional 1 For example, in AC servo motor control in industrial robots, etc., multiple operating axes are required, so the configuration circuit shown in FIG. 4 described above is required for each axis. As a result, the control device must be prepared for the number of axes, making the control device extremely expensive.
The purpose is to eliminate the above drawbacks in servo motor control.

(Means for solving the problem) The inventor of the present application devised the configuration circuit shown in FIG. /
] If such a switching means is provided, it is not necessary to prepare as many configuration circuits as there are axes as shown in FIG.

He thought he could save a considerable number of parts and provide an extremely inexpensive device, and he succeeded.

That is, the above-mentioned problem in the prior art is that in an AC servo motor switching control device that includes at least a resolver, a resolver position detection means, a motor excitation phase generation means, and an AC servo motor, the resolver position detection for l axes is difficult. This can be solved by temporally switching the motor excitation phase generating means or both. In this solution, preferably the power transistors for the l axis are switched and used. Preferably, the feedback signal from the resolver is switched and used. Furthermore, preferably, the speed detectors for the l-axis are switched and used.

(Embodiment) Fig. 1 shows the fourth embodiment in Fig. 0 showing the first embodiment of the present invention.
The same reference numbers as those in the figures indicate components having the same function, and the same reference numbers as those in FIG.
, B indicate components for the A and B axes, respectively, and have the same functions as those in FIG. 4.

In order to simplify the explanation, only the two sections A and B will be explained, but it will be easily understood that it can be carried out in exactly the same way for many axes beyond the B axis.

In FIG. 1, reference numeral 19 indicates a switch, and the switch 18 responds to a control signal X and outputs a digital counter 3A (
7) Output A, a-A, , ) a, or A. b~A,,b
Either one of them is output as the output signal A, ~A10. Further, reference numeral 20 indicates a switching relay, and this relay 20 is also switched by the control signal X to switch the output of each transistor pair 14, 15, 1B to the A phase.

It is designed to be switched for B phase use.

This first embodiment is applied to a system in which only the l-axis operates at the same time.For example, when it is desired to operate the A-axis, the control signal The output of the digital counter 3A is applied to the resolver position detector 4 via the switch 19, and the switching relay 20 is also switched so that each transistor pair 14.
15.16 output signal to A-axis servo motor 1? Apply to A side. In this way, by the action of the switch 19 and the switching relay 20, the resolver position detector 4, the reference wave counter 5. Fundamental wave oscillator 6, U-phase generator 7. V-sum generator8. W sum generator 9, resolver excitation circuit 10, U phase, ■
Phase and W phase PWM circuits, 12 and 13, U phase,
Transistor pair 14.15 and 1 for V phase and W phase
6 all operate to control the A-axis servo motor 17A. On the other hand, the level of control signal
In other words, if you set it to "high", it will be 1. The above elements conversely operate to control the B-axis servo motor 17B.

In this way, in the first embodiment, by providing the switch 19 and the switching relay 20, the resolver position detector 4, the basic wave counter 5. Reference wave oscillator 6, U-phase generator 7. V sum generator 8, W sum generator 9, resolver excitation circuit 1O5U phase, V phase and W phase PWM circuits 11, 12, 13, U phase, V phase O, W phase transistor pair 14 There is no need to provide as many .15 and 16 as there are axes, and only one each can be used.

FIG. 2 shows a second embodiment of the present invention. In this figure as well, the same reference numbers as in FIG. 4 or FIG. 1 indicate components having the same function, and the reference numbers in FIG. The same reference numbers as A and B are respectively A and B.
, which are for the B-axis and show structural elements having the same functions as those shown in FIG. However, it will be readily understood that it can be carried out in exactly the same way for multiple axes beyond the B axis.

The embodiment shown in FIG. 2 is different from the embodiment shown in FIG. is switched and applied to the PLL circuit 2, whereby the PL
The structure is such that only one L circuit 2 and one digital counter 3 are required. Switching relay 20
．． Both switching relays 21 are switched in response to control signal X. However, in this case, it is necessary to match the phase of the output value of the digital counter 3 and the detection signal of the resolver 18 each time the switching is performed. ! ;7) The switching relay 21 may be an analog switch or the like that is switched in response to the control signal X.

This second embodiment is also applied to a system in which only the l-axis operates at the same time.1 For example, when it is desired to operate the A-axis, the level of the control signal The output of the amplifier IA is the switching relay 21
is applied to the PLL circuit 2 via the resolver position detector 4 to generate an output signal for Afdl, and at the same time, the switching relay 20 is also switched to change the output signal of each transistor pair 14.15°16 to A. It is applied to the shaft servo motor 17A side. In this way, the switching relay 20
and 21, the PLL circuit 2, digital counter 3, resolver position detector 4, reference wave counter 5,
Reference wave oscillator6. U-phase generator7. V sum generator 8, W sum generator 9, resolver excitation circuit 10. PWM circuit for U phase, V phase and W phase! The elements of transistor pairs 14.15 and 18 for phases 1, 12 and 13.0, V and W phases all operate to control the A-axis servo motor +7A. On the other hand, when the level of the control signal X is set to "H", that is, "high", the above-mentioned elements operate in reverse to control the B-axis servo motor 17B.

In this way, in the second embodiment, by providing the switching relays 20.21, the PLL circuit 2, digital counter 3, resolver position detector 4, reference wave counter 5, reference wave oscillator 6. U phase generator 7, VJO generator 8
, W sum generator9. Resol 8 excitation circuit 1O1U phase, V phase and W phase PWM circuit 11.12 and 13, U phase, V
Transistor pair 14.15 and 1B for phase and W phase
There is no need to provide as many as the number of axes, and only one is required for each.

FIG. 3 shows the fourth embodiment in FIG.
The same reference numerals as those in FIG. 1, and FIG. , which are for the B axis and have the same functions as those shown in FIG.
It will be easily understood that the same method can be applied to many other axes.

:Jj3 The difference between the embodiment shown in FIG. 3 and the first embodiment shown in FIG. 1 is that the PWM circuit 11.12.13 and the output transistor pair 14.15.1B are IIA and IIB, respectively.

+2A, 128.13A, 13B and +4A, 14B
; 15A, 158; +8A.

188 for the number of axes, and selectors 22, 23, such as analog switches capable of high-speed switching.
24 to provide a U-phase generator 7. The outputs of the V-sum generator 8 and W-sum generator 9 are switched for the A-axis and B-axis, respectively, and each PWM
Circuit 11^, ■8.12A, 12B.

The point is that it is configured so that it can be applied to 13A and 13B.

In addition, 25A, 25B, 26A, 28B, 27A, 2
7B is a resistor for U phase, ■ phase, and W phase, respectively, 28A,
28B, 29A, 29B.

3OA and 30B indicate capacitors for the U phase, ■ phase, and W phase, respectively.

The first and second embodiments described above were applied to servo control in which only one axis operates at the same time, but this third embodiment is of course applicable to servo control in which only one axis operates at the same time. , applicable to devices that can operate two or more at the same time1
It is @.

In the latter case, the switch 19 is configured as a switching circuit that can switch the digital signal very quickly, and the switch 22, 23, 24 is also configured as a switching circuit that can switch the analog signal very quickly.

Here, when the level of the control signal It is applied to the generator 7, the V-phase generator 'Jji8, and the W-sum generator 9. That is, a signal corresponding to the rotation angle of the resol/18A is given to the U-phase generator 7, V-phase generator 8, and W-sum generator 9. In this step, voltages are created according to the U phase, V phase, and W phase of the A Oh servo motor 17A. At this point, switchers 22, 23 and 24
is still switched to the A-axis side, and the outputs of the U-phase generator 7, V-phase generator 8 and W sum generator 9 are connected to the capacitor 2 through resistors 25A, 26A and 27A, respectively.
P as stored in 8A, 29A and 30A
The level of the 0th order signal X input to the WM circuits 11A, 12A and +3A becomes "H", that is, r high
Even if the switches 22, 23 and 24 do not switch to the B-axis side, the input voltages to the PWM circuits 11A, 12A and 13A are maintained by the capacitors 28A, 29A and 30A. Also, at the same time that the switches 22, 23 and 24 switch to the B-axis side, the switch 19 also switches! ,'] changed,
The output of the digital counter 3B is given to the resolver position detector 4 via the switch 19, and the same control as on the A-axis side is performed on the B-axis.
This is done on the shaft side. Therefore, the level of control signal
``If high-j switching is repeated at extremely high speed, each phase of the servo motors 17A and 17B will have resolvers 18A and 18B.
′i [force is applied according to the rotation angle of both servo motors l? Rotations of A and 17B can be controlled simultaneously.

In this third embodiment, a resolver position detector 4, a reference wave counter 5, a reference wave oscillator 6, a U phase generator 7, a V phase generator 8, a W sum generator 9. Only one resolver excitation circuit 10 is required.

(Effect of the invention) In the AC servo motor switching control device having N axes, the resolver position detector 4, U phase, V phase and W phase
Originally, it is necessary to prepare eight circuits such as the sum generators 7, 8, 9, etc., but according to the present invention, the AC servo motor switching control device for N axes can be configured with one or fewer than N circuits. Therefore, it is possible to realize an extremely inexpensive and compact AC servo motor switching control device.

[Brief explanation of drawings]

FIG. 1 is a block circuit diagram showing a first embodiment of the AC servo motor switching control device according to the present invention, and FIG. 2 is a block circuit diagram showing a second embodiment of the AC servo motor switching control device according to the present invention. FIG. 3 is a blow 2 circuit diagram showing a third embodiment of an AC servo motor switching control device according to the present invention, and FIG. 4 is a block circuit diagram showing a conventional example of an AC servo motor control device to which the present invention is applied. be. (Explanation of symbols) 1, ,, operation #a width unit. 2. PLL circuit. 3. Digital counter; 4. Resolver position detector; 5. Reference wave counter. 6. Reference wave oscillator. 7, tJ phase generator, 8, V sum generator, 9, W sum generator, 10, resolver excitation circuit, 11, U phase PWM circuit, +2 ．． , , V-phase PWM circuit, +3. ,,,W J [l P W M D path. 14. U-phase power transistor pair. 15, , V-phase power transistor pair, 18, ,
W-phase power transistor pair, 17, AC servo motor. +8. , ,Controlled resolver. 19.,,,switcher, 20-21. ,, Relay for lFJ replacement. 22nd race 23rd/24th. ,,,Switcher, 31,,,Speed detector.

Claims (4)

[Claims] (1) In an AC servo motor switching control device including at least a resolver, a resolver position detection means, a motor excitation phase generation means, and an AC servo motor, the
An AC servo motor switching control device, characterized in that a servo device with two or more axes is controlled by temporally switching resolver position detection means or motor excitation phase generation means or both for the axes. (2) The AC servo motor switching control device as set forth in claim 1, characterized in that a servo device with two or more axes is controlled by switching and using power transistors for one axis. . (3) The AC servo motor switching control device as set forth in claim 1, characterized in that a servo device with two or more axes is controlled by switching and using feedback signals from a resolver. (4) The AC servo motor switching control device as set forth in claim 1, characterized in that speed detectors for one axis are switched and used.