JP2010110146A - Drive unit of multi-phase linear motor, and drive control device equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately control a mover of a multi-phase linear motor having a plurality of coils at each phase while suppressing an increase of manufacturing cost. <P>SOLUTION: This drive unit of a multi-phase linear motor is provided with: an impedance adjusting coil 17 which is connected to a motor driver circuit 14 in series thereto, and equalizes synthetic impedance synthesized with all the coils and the synthetic impedance of a phase-corresponding partial coil when drive currents are fed to all the phase-corresponding coils; and an impedance adjusting switch 18 which connects the motor driver circuit 14, the impedance adjusting coil 17 and power feed changeover switches 19a to 19g which are related to all the coils in series to one another, and when the drive current is fed to the phase-corresponding partial coil, connects the motor driver circuit 14 to the power feed changeover switch related to the partial coil in series with each other not through the impedance adjusting coil 17. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a drive device for a multi-phase linear motor having a plurality of coils for each phase, and a drive control device having the drive device.

  Some linear motors are called MM (Moving Magnet) type including a stator having a plurality of coils for each phase and a mover having a permanent magnet. In this MM type linita motor, there are a case where all the coils of each phase are excited to move the mover and a case where some coils of each phase are sequentially excited to move the mover.

  In such an MM type linear motor drive device, a changeover switch is provided for each coil of each phase, and by controlling the changeover switch for each coil, the coil excitation state of each phase, The excitation state of only some of the coils is realized. However, if the entire coil excitation state of each phase and the excitation state of only a part of the coils of each phase are realized simply by controlling the changeover switch, a change in the response characteristic of the excitation current between the two states occurs. The mover cannot be controlled accurately.

  Therefore, in the drive device disclosed in Patent Document 1 below, a characteristic changing unit that suppresses a change in the response characteristic of the excitation current is provided. This characteristic changing unit is configured to include a plurality of resistors and a plurality of coils, and the command current value input to the motor drive circuit that supplies the drive current to the coils is set to the all coil excitation state of each phase and one of each phase. It changes with the excitation state of only a part coil.

JP 2005-304121 JP

  However, the above prior art is an excellent technique that can accurately control the mover by suppressing the change in the response characteristics of the excitation current between the excitation state of all the coils of each phase and the excitation state of only a part of the coils of each phase. However, there is a problem that the circuit configuration becomes complicated and the manufacturing cost increases.

  The present invention pays attention to such problems of the prior art, and a drive device for a multiphase linear motor capable of accurately controlling a motor mover while suppressing manufacturing cost, and a drive control device including the same The purpose is to provide.

A drive device for a multi-phase linear motor according to the invention for solving the above problems is as follows:
In a multiphase linear motor drive device comprising a plurality of coils for each phase,
For each of the phases of the multiphase linear motor, a motor drive unit that supplies a drive current,
The motor drive unit for each phase is respectively
A motor drive circuit that outputs a drive current to be supplied to the corresponding phase of the multiphase linear motor, and a first switch that performs supply and disconnection of the drive current from the motor drive circuit for every coil of the corresponding phase When a drive current is supplied to all the coils of the corresponding phase by the operation of the first changeover switch and the switch is connected in series to the motor drive circuit, the combined impedance of all the coils is set to the corresponding phase. An impedance member that is equivalent to the combined impedance of some of the coils, and when supplying a drive current to all the coils of the corresponding phase, the motor drive circuit, the impedance member, and the first changeover switch for the all coils; Are connected in series, and when the drive current is supplied to the partial coils of the corresponding phase, the motor drive circuit and the A second changeover switch for the said first changeover switch related parts of the coil are connected in series, and having a.

In addition, a drive control device for a multi-phase linear motor for solving the above problems is
The above drive device, and a control device that outputs a switching signal to the first changeover switch and the second changeover switch of the motor drive unit for each phase are provided.

  According to the present invention, the motor movable element can be accurately controlled with a simple configuration and without cost.

  Embodiments of a drive control apparatus for a multiphase linear motor according to the present invention will be described below with reference to the drawings.

As shown in FIG. 2, the multiphase linear motor 30 that is driven and controlled by the drive control device of the present embodiment includes a mover 31 having a plurality of coils for each of the U phase, the V phase, and the W phase, and a permanent magnet. It is a MM type linear motor provided with the needle | mover 32 which has 32m. For example, each coil of the mover 31 includes a U-phase first coil U ₁ , a V-phase first coil V ₁ , a W-phase first coil W ₁ , a U-phase second coil U ₂ , and a V-phase first coil. second coil V _2, W-phase of the second coil W _2, U-phase of the third coil U _3, the third coil V ₃ V-phase, W-phase of the third coil W _3, ... are arranged in this order.

  In this linear motor 30, when the exact position of the mover is unknown on the drive control device side, all coils of all phases are excited as shown in FIG. When the accurate position of the mover is grasped, two coils of each phase are selectively excited sequentially as shown in FIG. In the figure, the excited coil is hatched. Here, the number of coils in each phase is seven, and two coils are excited at the time of partial excitation. However, these numbers are not intended to limit the present invention.

  As shown in FIG. 1, the drive control device that drives and controls the linear motor 30 described above includes a control device 20 that outputs a current command indicating a current value of a drive current supplied to each phase of the linear motor 30, and a power supply circuit. And a drive device 10 that adjusts the electric power from 40 to a drive current according to a current command for each phase and supplies it to each phase of the linear motor 30.

  Functionally, the control device 20 includes a current command generation unit 21 that generates the above-described current command and a switching command generation unit 22 that generates a switching command for each switch described below. The control device 20 is a computer in terms of hardware, and includes a CPU that executes various arithmetic processes, a ROM that stores programs and data executed by the CPU in advance, and a RAM that serves as a work area for the CPU. And an input device such as a keyboard, and an interface for transmitting and receiving signals between the driving device 10 and the three-phase linear motor 30. Each of the aforementioned functional units 21 and 22 of the control device 20 functions when the CPU executes a program stored in a ROM or the like.

Drive 10, the U-phase coil 31u ₁ of the linear motor 30, 31u _2, a U-phase driver 11u for supplying a current to ..., each V-phase coil 31v _1, 31v _2, V-phase for supplying current to ... A drive unit 11v, a W-phase drive unit 11w that supplies current to the W-phase coils 31w ₁ , 31w ₁ ,..., A D / A converter 12 that converts a digital signal indicating a current command from the control device 20 into an analog signal, ,have.

Each of the drive units 11u, 11v, and 11w of each phase amplifies the current detector 15 that detects the current value of the drive current supplied to the corresponding phase of the linear motor 30, and the output from the current detector 15. Current feedback control for outputting a new current command indicating a current value corresponding to a deviation between the current command value from the amplifier 16 and the control device 20 converted into an analog signal by the D / A converter 12 and the output from the amplifier 18 Unit 13, motor driver circuit 14 that supplies a drive current corresponding to the current command value from current feedback control unit 13 to corresponding phase U of linear motor 30, impedance adjustment coil 17 as an impedance member, and motor driver circuit 14 An impedance adjustment switch (second switching switch) for switching the impedance adjustment coil 17 between a connected state and a disconnected state. And pitch) 18, all coils 31u of the corresponding phase U _1, 31u _2, ..., 31u ₇ power supply changeover switch connected to the respective (first change-over switch) 19a, 19b, ..., and a 19g ing.

  The motor driver circuit 14 includes a PWM (Pulse Width Modulation) control circuit (not shown) to which a current command is input from the feedback control unit 13 and a current value corresponding to the output from the power supply circuit 40 according to the output from the PWM control circuit. And an output stage circuit (not shown) for supplying the driving current to the corresponding phase U. Here, a PWM control circuit with high efficiency and low heat generation is used for current value control, but another control circuit such as a linear control circuit may be used instead.

  The power supply changeover switches 19a, 19b,..., 19g are connected in parallel to the motor driver circuit 14. Each of the power supply changeover switches 19a, 19b,..., 19g is driven by a switching command from the switching command generation unit 22 of the control device 20. This switching command is sent to each power supply switching switch 19a, 19b,..., 19g as a digital signal without passing through the D / A converter 12.

  The impedance adjustment coil 17 is connected in series to the power supply changeover switch group. The impedance adjustment switch 18 includes a state in which the motor driver circuit 14, the impedance adjustment coil 17, and the power supply changeover switch group are connected in series, and the motor driver circuit 14, power supply changeover switch group, and the like without passing through the impedance adjustment coil 17. Are switched to the state of being connected in series. The impedance adjustment switch 18 is also driven by a switching command from the switching command generation unit 22 of the control device 20, similarly to the power supply switching switches 19 a, 19 b,.

  Next, the operation of the drive control device of this embodiment will be described.

  When the driving position of the movable element 32 is unknown on the drive control device side, such as when the drive of the linear motor 30 is started, the current command generation unit 21 of the control device 20 applies to all the coils of each phase of the linear motor 30. A current command for supplying an alternating current having a predetermined current value is output.

  When the feedback control unit 13 receives the current command from the current command generation unit 21, the feedback control unit 13 indicates a current value corresponding to a deviation between the current value indicated by the current command and the current value detected by the current detector 15. Is output. The motor driver circuit 14 outputs a drive current corresponding to the current value indicated by the current command.

  When the current command is output from the current command generation unit 21 of the control device 20, the switching command generation unit 22 of the control device 20 applies the impedance adjustment switch 18 and the total power supply switch 19a, 19b,. Switch command is output. This switching command is a switching command to the connection state for each of the power supply switching switches 19a, 19b,. Therefore, all the power supply changeover switches 19a, 19b,..., 19g are in a connected state as shown in FIG. In addition, when the impedance adjustment switch 18 receives a switching command to connect to all the power supply changeover switches 19a, 19b,..., 19g, the motor driver circuit 14, the impedance adjustment coil 17, and the power supply changeover switch group are connected in series. To the state.

As a result, the drive current output from the motor driver circuit 14 is supplied to the coils 31u ₁ , 31u ₂ ,..., 31u ₇ via the impedance adjustment coil 17 and the power supply changeover switches 19a, 19b,. All the coils 31u ₁ , 31u ₂ ,..., 31u ₇ of the corresponding phase U are excited.

At this time, taking the drive current to the motor driver circuit 14 of the corresponding phase U is supplied, the impedance of the motor side, the total coil 31u ₁ of the corresponding phase U and impedance adjustment coil 17, 31u _2, ..., the combined impedance _{Z A} of 31u ₇ It becomes. Specifically, the combined impedance _{Z A,} each coil _{31u 1, 31u 2, ...,} 31u 7 the respective impedances and Z _1, the impedance of the impedance adjustment coil 17 When Z _0, the values shown in the following equation Become.

Z _A = Z ₀ + 1 / (1 / Z ₁ + 1 / Z ₁ + 1 / Z ₁ + 1 / Z ₁ + 1 / Z ₁ + 1 / Z ₁ + 1 / Z ₁ )
= Z ₀ + Z _1/7
Here, if, when the impedance Z ₀ of the impedance adjustment coil 17, 5Z _1/14, the synthetic impedance Z _A at this _time, the following values.

_{Z A = Z 0 + Z 1} /7
_{= 5Z 1/14 + Z 1} /7
= 7Z _1/14
= Z _1/2
Once all the coils of all phases are energized and once the exact position of the mover is grasped on the drive control device side, the current command generation unit 21 of the control device 20 thereafter performs the operation for all the phases of the linear motor 30. A current command for supplying an alternating current having a predetermined current value is output to two of the coils. The two coils are sequentially changed to the other two coils as the motor mover moves. Then, as described above, the motor driver circuit 14 outputs a drive current corresponding to the current value indicated by the current command from the feedback control unit 13.

  Further, when the current command generating unit 21 of the control device 20 outputs a current command for supplying an alternating current having a predetermined current value to the two coils of each phase, the switching command generation of the control device 20 is also performed. A switching command is output from the unit 22 to the impedance adjustment switch 18 and the total power supply switching switches 19a, 19b,. This switching command is, for example, a switching command for switching to a connected state with respect to two power supply switching switches 19a and 19b among all the power supply switching switches 19a, 19b,. This is a switching command to the disconnection state for the changeover switches 19c, 19d,.

  For this reason, the two power supply changeover switches 19a and 19b that have received the command to switch to the connected state are in the connected state as shown in FIG. 2B, and the rest that has received the command to switch to the disconnected state. The power supply changeover switches 19c, 19d,..., 19g are disconnected. When the impedance adjustment switch 18 receives a command to switch to a connection state with respect to a certain two power supply changeover switches 19a and 19b, the impedance adjustment switch 17 does not go through the impedance adjustment coil 17 and the power supply changeover switch group. Are connected in series. The impedance adjustment switch 18 is switched not only when it receives a command to switch to a connection state for two specific power supply changeover switches 19a and 19b, but also to switch to a connection state for any two power supply changeover switches. Even when the command is received, the motor driver circuit 14 and the power supply selector switch group are connected in series without passing through the impedance adjustment coil 17. That is, once the accurate position of the mover is grasped on the drive control device side, the impedance adjustment switch 18 connects the motor driver circuit 14 and the power supply changeover switch group in series without going through the impedance adjustment coil 17. Maintain the state.

As a result, the drive current output from the motor driver circuit 14 does not pass through the impedance adjustment coil 17 but passes through the two connected power supply changeover switches 19a and 19b to the two coils 31u ₁ and 31u ₂ . Only the _two coils 31u ₁ and 31u ₂ are excited.

At this time, taking the drive current to the motor driver circuit 14 of the corresponding phase U is supplied, the impedance of the motor side, the two synthetic impedance Z _P of the coil 31u _1, 31u ₂ corresponding phases U. Specifically, the composite impedance Z _P becomes a value shown in the following equation.

Z _P = 1 / (1 / Z ₁ + 1 / Z ₁ )
= Z _1/2
Here, it should be noted that for the motor driver circuit 14 of the corresponding phase U that supplies the drive current, the impedance on the motor side is either in the excited state of all the coils or in the excited state of only two coils. in Z _1/2, in that the same.

  For this reason, in this embodiment, the change of the response characteristic of the excitation current in the all-coil excitation state of each phase and the excitation state of only the partial coil of each phase can be suppressed, and the mover 32 can be controlled accurately. In addition, in the present embodiment, the above effect can be obtained only by adding the impedance adjustment coil 17 and the impedance adjustment switch 18, and thus the manufacturing cost can be reduced.

  In the above embodiment, as the switching command for the impedance adjustment switch 18, the switching command for the power supply switching switches 19c, 19d,..., 19g is used. The switching command and the switching command for the power supply switching switches 19c, 19d,..., 19g may be output separately.

  In the above embodiment, the impedance adjustment coil 17 is provided in the driving device 10, but it may be provided in the linear motor 30.

1 is a configuration diagram of a polyphase linear motor and a drive control device thereof as one embodiment according to the present invention. It is explanatory drawing which shows the state of the polyphase linear motor as one Embodiment which concerns on this invention, and its drive device.

Explanation of symbols

10: drive device, 11u: U-phase drive unit, 11v: V-phase drive unit, 11W: W-phase drive unit, 12: D / A converter, 13: current feedback control unit, 14: motor driver circuit, 15: current detection 17: Impedance adjustment coil (impedance member), 18: Impedance adjustment switch (second changeover switch), 19a to 19g: Power supply changeover switch, 20: Control device, 21: Current command generator, 22: Switch command Generating unit, 30: polyphase linear motor, 31: stator, 31u: U phase coil, 31v: V phase coil, 31W: W phase coil, 32: mover, 40: power supply circuit

Claims (2)

In a multiphase linear motor drive device comprising a plurality of coils for each phase,
For each of the phases of the multiphase linear motor, a motor drive unit that supplies a drive current,
The motor drive unit for each phase is respectively
A motor drive circuit for outputting a drive current to be supplied to the corresponding phase of the multiphase linear motor;
A first changeover switch for supplying and disconnecting the drive current from the motor drive circuit for every coil of the corresponding phase;
When the drive current is supplied to all the coils of the corresponding phase by the operation of the first changeover switch in series with the motor drive circuit, the combined impedance with all the coils is set to a part of the corresponding phase. An impedance member equivalent to the combined impedance of the coil;
When supplying a drive current to all the coils of the corresponding phase, the motor drive circuit, the impedance member, and the first changeover switch for the all coils are connected in series, and the partial coils of the corresponding phase A second changeover switch that connects the motor drive circuit and the first changeover switch relating to the partial coil in series without passing through the impedance member when supplying a drive current;
A drive device for a multi-phase linear motor, characterized by comprising: A driving device for a multi-phase linear motor according to claim 1;
A control device that outputs a switching signal to the first changeover switch and the second changeover switch of the motor driving unit for each phase;
A drive control device for a multi-phase linear motor, comprising:

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