JP4626744B2 - Linear motor control device and control method - Google Patents

Description

  The present invention relates to a linear motor control device and a linear motor control method for driving a plurality of linear motors using a plurality of current control devices.

In a conventional linear motor current control device, a multi-phase motor having a plurality of coils and driving a table, command means for commanding an energization current value to each coil, and energization according to the position of the table In a positioning table device having means for selecting a power coil and a servo circuit for controlling the energization current to the selected coil to coincide with the commanded current value, the coils are sequentially arranged based on a predetermined energization pattern. When moving the table while switching, the current command to the servo circuit that drives the coil is gradually changed so that the combined current of each coil before and after switching is substantially constant, and the current command value of each coil and the coil A means for multiplying the selection signal is provided, and the coil selection signal is delayed so that the current loop is not saturated immediately after switching the coil (for example, References 1).
In FIG. 5, reference numeral 104 denotes a linear motor coil in which four-phase coils are arranged in a straight line. The linear motor coil 104 is supported by a coil support member 103 and is parallel to the direction in which the coils constituting the linear motor coil 104 are arranged. A pair of guides 102 is provided. A pair of upper and lower table top plates 101 are attached to the guide 102 so as to sandwich the linear motor 104 via the guide portion 111, and the pair of upper and lower table top plates 101 are slid by the guide 102 in the direction in which the coils are arranged. Guided freely. As the guide portion 111, rolling, sliding, stationary guide, etc. are used in consideration of positioning accuracy and maintainability. A movable magnet 105 is attached to each of the pair of upper and lower table top plates 101, and the movable magnet 105 is composed of four permanent magnets arranged alternately in the direction in which the coils are arranged. The movable magnets 105 are attached to the table top plate 101 through the linear motor coils 104 so as to face each other with different polarities.
Further, a position detector 106 such as a linear scale for detecting the position of the table top plate 101 is provided on the side of the guide 102. A counter unit 107 that obtains a table position signal is connected to the position detector 106, and a phase switching controller 109 for switching each coil phase is connected to the counter unit 107. The phase switching controller 109 outputs a coil selection signal (on / off signal) for each coil for switching a coil to be energized in accordance with a table position signal from the counter unit 107. The coil selection signal for each coil is input to one input terminal of each multiplier 113 provided for each coil. The coil phase is connected to the multiplier 113 via the current amplifier 110, and the output of the multiplier 113 is turned on / off by a coil selection signal (on / off signal) from the phase switching controller 109 to each coil phase. Is switched on. The counter unit 107 is connected to a servo controller 108 that calculates a difference between the target position of the table and the current position obtained from the counter unit 107 and outputs the difference to each current amplifier 110 as a command value.
A filter circuit 112 is connected to a digital output coil selection signal output terminal for turning on / off each coil of the phase switching controller 109. The coil selection signal subjected to the filter processing (delay processing) by the filter circuit 112 and the current command value of each coil from the servo controller 108 are multiplied by the multiplier 113 to become a current command signal to the current amplifier 110. In the apparatus shown in FIG. 5, the filter circuit 112 can control the current command value signal, that is, the switching characteristics of each coil during phase switching.
As described above, in the conventional linear motor current control device, a multi-phase motor having a plurality of coils and driving a table, command means for commanding an energization current value to each coil, and a position of the table. In accordance with a predetermined energization pattern in a positioning table device provided with means for selecting a coil to be energized in response and a servo circuit for controlling the energization current to the selected coil to coincide with the commanded current value When the table is moved while switching the coils sequentially, the current command to the servo circuit that drives the coil is gradually changed so that the combined current of each coil before and after switching is substantially constant, and the current of each coil A means for multiplying the command value and the coil selection signal is provided, and the coil selection signal is delayed so that the current loop is not saturated immediately after the coil switching. Cormorants steps had been taken.
Japanese Patent Laid-Open No. 7-134618 (page 3-4, FIG. 1)

  However, in the prior art, a position detector such as a linear scale for detecting the position of the mover is required to drive the phase switching controller, and there is a problem that the reliability is lowered in addition to being expensive. The present invention has been made in view of such problems, and provides a linear motor control device that can perform a plurality of linear motor switching control without using a linear scale and has a small speed ripple, and a control method therefor. With the goal.

The present invention described in claim 1 includes a plurality of stators composed of multiphase coils, a mover composed of multipolar permanent magnets straddling at least one of the plurality of stators, and A linear motor control device including means for selecting a stator to be energized according to the position of a mover, a current command generation unit that generates a current command using a speed command, and a current detection unit that detects current A current control unit that generates a voltage command so that the current detection value detected by the current detection unit matches the current command, a position generation unit that integrates the speed command to generate an estimated position, and a voltage command A current control device including a voltage output unit that outputs a voltage using the estimated position, and the current control device is connected to one stator, and the linear motor includes at least two current control devices. To drive system The stator coil number discriminating unit for discriminating the number of stator coils driving the mover using the speed command, current command, voltage command, and motor constant, and the results of the stator coil number discriminating unit And a current adjusting unit that adjusts a current value for driving the mover using the estimated position.
The present invention described in claim 2 includes a plurality of stators composed of multiphase coils, a mover composed of multipolar permanent magnets straddling at least one of the plurality of stators, and A control method for a linear motor comprising means for selecting a stator to be energized according to the position of a mover, a current command generation unit for generating a current command using a speed command, and a current detection unit for detecting a current A current control unit that generates a voltage command so that the current detection value detected by the current detection unit and the current command match, a position generation unit that integrates the speed command to generate an estimated position, and the voltage command In a linear motor drive system including a voltage control unit configured to output a voltage using an estimated position, and the current control device connected to one stator and having at least two current control devices Fixed The step of determining the number of coils of the stator driving the mover by the number of coils determination unit of the current, and the current adjustment unit by the current adjustment unit according to the coil number determination result of the stator and the estimated position And a step of adjusting the magnitude of the command.
According to a third aspect of the present invention, in the linear motor control device according to the first aspect, the coil number determination unit of the stator uses a current sensor signal instead of the current command, and the stator driving the mover. The number of coils is discriminated.
According to a fourth aspect of the present invention, in the linear motor control method according to the second aspect, the stator coil number discriminating unit uses a current sensor signal instead of the current command, and the stator driving the mover. The number of coils is discriminated.
According to a fifth aspect of the present invention, in the linear motor control device according to the first aspect, the stator coil number discriminating unit drives the mover using a speed feedback signal from a speed sensor instead of a speed command. The number of coils of the stator is determined.
According to a sixth aspect of the present invention, in the linear motor control method according to the second aspect, the stator coil number discriminating unit uses a speed feedback signal from a speed sensor instead of a speed command to drive the mover. The number of stator coils is determined.
According to a seventh aspect of the present invention, in the linear motor control device according to the first aspect, the coil number determination unit of the stator includes:
N ² = {(R · I) ² + (ωL · I) ² } / {V1 ² −2 · V1 · φω + (φω) ² }
Where N is the number of coils driving the mover, I is a current command, R · I is a voltage drop due to resistance, ωL · I is a voltage drop due to inductance, V1 is a voltage command, and φω is fixed using an induced voltage. The number of coils of the child is obtained.
The present invention according to claim 8 is the linear motor control device according to claim 2, wherein the number-of-coil determination unit of the stator is
N ² = {(R · I) ² + (ωL · I) ² } / {V1 ² −2 · V1 · φω + (φω) ² }
Where N is the number of coils driving the mover, I is a current command, R · I is a voltage drop due to resistance, ωL · I is a voltage drop due to inductance, V1 is a voltage command, and φω is fixed using an induced voltage. The number of coils of the child is obtained.
According to a ninth aspect of the present invention, in the linear motor control device according to the first aspect, the current adjusting unit changes the current amplitude in a ramp shape according to the estimated position.
According to a tenth aspect of the present invention, in the linear motor control method according to the second aspect, the current adjusting section changes the current amplitude in a ramp shape according to the estimated position.

  According to the present invention, since a position detector such as a linear scale that detects the position of the mover for driving the phase switching controller can be eliminated, the reliability can be improved at a lower cost. Furthermore, a linear motor control device and a control method thereof can be provided that can control a plurality of linear motors without using a linear scale and have a small speed ripple.

  Hereinafter, specific examples of the method of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a linear motor current control apparatus that implements the method of the present invention. In the figure, 1 is a current adjusting unit that adjusts the current flowing through the linear motor according to the result of the stator coil number discriminating unit 3, 2 is a current command generating unit that generates a current command from the speed command 4, and 3 is a speed command. 4 and the first thrust current command (IqrefA) and the first exciting current command (IdrefA) a voltage command and the number of coils determination of the stator to determine the number of coil stator which drives the mover using the motor constant Reference numeral 4 denotes a speed command, 5 denotes a current control unit that generates a voltage command so that the current command and the current detected by the current detection means 18 match, and 6 denotes a first thrust current command generated by the current command generation unit 2. (IqrefA), 7 is a first excitation current command (IdrefA) generated by the current command generation unit 2, 8 is a position generation unit that integrates the speed command 4 to generate a position, and 9 is generated by the current control unit 5. Thrust voltage command (Vq ef), an excitation voltage command, and a position generated by the position generator 8, a two-phase / three-phase converter that performs two-phase / three-phase conversion, 10 is a dead time compensator that performs dead time compensation, and 11 is dead time compensation. PWM controller for applying voltage to the linear motor according to the voltage command output from the unit 10, 12 is a linear motor composed of a plurality of stators and a mover straddling the plurality of stators, and 13 is adjusted by the current adjusting unit 1. The second thrust current command (IqrefB), 14 is the second excitation current command (IdrefB) adjusted by the current adjustment unit 1, 15 is the thrust voltage command (Vqref) generated by the current control unit 5, and 16 is the current control. The excitation voltage command (Vdref) 17 generated by the unit 5 is composed of the two-phase / three-phase conversion unit 9, the dead time compensation unit 10, the PWM control unit 11, and the like, and the voltage command output from the current control unit 5 and A voltage output section that outputs a voltage by using the position generated by the location generation unit 8, 18 is a current detector.
FIG. 2 is a system configuration diagram showing a configuration of a linear motor current control apparatus to which the method of the present invention is applied. In the figure, 19 is a current control device, 20 is a mover constituting the linear motor 12 and straddles a plurality of stators 21, and 21 is a stator constituted by multiphase coils constituting the linear motor 12. The linear motor 12 is composed of a plurality of stators 21.
FIG. 4 is a current amplitude pattern of the present invention. In the figure, 31 is the current amplitude pattern of the current control device 19 driving the stator 21 through which the mover passes when the linear motor 12 is driven, and 32 is when the linear motor 12 is driven. The current amplitude pattern of the current control device 19 driving the stator 21 into which the mover enters, and 33 is the total current amplitude pattern of the two current control devices. The stator excitation can be switched smoothly without changing the total thrust.
Driven according to the speed command 4 a linear motor 12 consists of movable member 20 straddling the formed stator 21 with stator 21 and a plurality of multi-phase coils composed of a plurality of multi-phase coils of a plurality of current control device 19 to determine the number of coil stator which drives a movable element with a case, the equation (1) in the coil number determination section 3 of the stator to be. In equation (1), N is the number of coils of the stator driving the mover, ω is the speed command 4, I is the first thrust current command (IqrefA) 6 and the first excitation current command (IdrefA) 7 . The current command calculated by the equation (3) , V1 is a voltage command calculated by the equation (2) using the thrust voltage command (Vqref) 15 and the excitation voltage command (Vdref) 16. The current adjustment unit 1 adjusts the magnitude of the current command based on the stator coil number determination result of the stator coil number determination unit 3 and the estimated position generated by the position generation unit 8, and the second thrust current A command (IqrefB) 13 and a second excitation current command (IdrefB) 14 are generated, and the current detected by the current detection means 18 in the current control unit 5, the second thrust current command (IqrefB), and the second excitation current command (IdrefB) ) To generate a thrust voltage command (Vqref) 15 and an excitation voltage command (Vdref) 16, and the two-phase / three-phase converter 9 generates the thrust voltage command (Vqref) 15, the excitation voltage command (Vdref) 16 and Two-phase three-phase is performed using the position generated by the position generation unit 8, the output voltage command of the two-phase three-phase conversion unit 9 is compensated for dead time by the dead time compensation unit 10, and dead The output voltage command Im compensator 10 drives the linear motor 12 by PWM control by the PWM control unit 11. The current pattern generated by the current adjusting unit 1 is changed in a ramp shape according to the estimated position like the current amplitude pattern 31 and the current amplitude pattern 32 when the movable element to be driven straddles a plurality of stators. The linear motor 12 is driven by the total current amplitude pattern 33 of the two current control devices 19, and the thrust ripple and the speed ripple can be reduced when the mover straddles a plurality of stators.

N ² = {(R · I) ² + (ωL · I) ² } / {V1 ² −2 · V1 · φω + (φω) ² }
... (1)
V1 = √ (Vdref ² + Vqref ² ) (2)
I = √ (IqrefA ² + IdrefA ² ) (3)

FIG. 3 is a flowchart showing the processing procedure of the present invention. The method of the present invention will be described step by step with reference to this figure.
First, in step 22, V1 calculated from equation (2) using the thrust voltage command (Vqref) 15 and the excitation voltage command (Vdref) 16 is fetched.

Calculates V1 and V1 ² at step 23, the square of the induced voltage Faiomega and induced voltage ^{(φω) 2} calculated in step 24, in step 25, a denominator of Equation (1) ^V1 2 -2 · ^V1
Φω + (φω) ² is calculated, the voltage RI for the resistance and the square of the voltage for the resistance (RI) ² are calculated in step 26, and the voltage ωLI for the reactance and the square of the voltage for the reactance (ωLI) in step 27 ² is calculated, N ² is calculated using equation (1) in step 28,
In step 29, the number of stator coils is determined from the result of step 28 using the stator coil number determination criterion. In step 30, the stator coil number determination result of step 29 is used to determine the current amplitude pattern 31 and the current. By adjusting the current to generate the amplitude pattern 32, the linear motor 12 is driven by the total current amplitude pattern 33 of the two current control devices 19 when the mover straddles a plurality of stators, and the mover The thrust ripple and the speed ripple can be reduced by changing the current amplitude in the case of straddling a plurality of stators in a ramp shape according to the estimated position.

In formula (1) of step 28 for obtaining the square of the number of coils of the stator in the flowchart showing the processing procedure of FIG. 3, ω is speed feedback that is simpler than a linear scale such as a speed generator or FG (frequency generator). Using the signal, I uses the first thrust current command (IqrefA) 6 and the first excitation current command (IdrefA) 7 generated by the current command generator 2, V1 uses the thrust voltage command (Vqref) 15, and the excitation voltage command. By determining the number of stator coils using the voltage command calculated by the equation (2) using (Vdref) 16 and performing current adjustment in the current adjustment unit 1, the mover 20 has a plurality of stators 21. The current amplitude when straddling is changed in a ramp shape according to the estimated position, and the thrust ripple and the speed ripple can be reduced.

In formula (1) of step 28 for obtaining the square of the number of coils of the stator in the flowchart showing the processing procedure of the method of the present invention of FIG. 3, ω uses the speed command 4 and I uses the current sensor signal. Using the thrust current and the excitation current detected in this way, V1 is the number of stator coils determined using the voltage command calculated by equation (2) using the thrust voltage command (Vqref) 15 and the excitation voltage command (Vdref) 16. Then, by adjusting the current in the current adjusting unit 1, the current amplitude when the movable element 20 straddles the plurality of stators 21 is changed in a ramp shape according to the estimated position, thereby reducing the thrust ripple and the speed ripple. be able to.

Even if there is no position detector such as a linear scale, the current position of multiple linear motors is estimated by the estimated position obtained from the speed command at the same time as determining the number of stators and stator coils that the linear motor mover straddles. The thrust ripple and speed ripple are reduced by changing to a ramp shape according to. This technology can be expected to be applied not only to conveying devices and moving devices that use linear motors, but also to machine tools and industrial machines.

The block diagram which shows the structure of the linear motor current control apparatus which adapts the method of this invention. The system block diagram which shows the structure of the linear motor current control apparatus to which the method of this invention is applied. The flowchart which shows the process sequence of the method of this invention. The current amplitude pattern of this invention. The system block diagram which shows the structure of the linear motor current control apparatus to which the conventional method is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Current adjustment part 2 Current command production | generation part 3 Coil number discrimination | determination part 4 Speed command 5 Current control part 6 1st thrust current command (IqrefA)
7 First excitation current command (IdrefA)
8 Position generation unit 9 Two-phase three-phase conversion unit 10 Dead time compensation unit 11 PWM control unit 12 Linear motor 13 Second thrust current command (IqrefB)
14 Second excitation current command (IdrefB)
15 Thrust voltage command (Vqref)
16 Excitation voltage command (Vdref)
17 voltage output unit 18 the current detecting means 19 step 25 of calculating a step 24 Faiomega and ^{(φω) 2} calculates the steps 23 V1 and V1 ² for taking a current control device 20 the movable element 21 the stator 22 ^V1 V1 2 -2 · V1 Step 26 for calculating φω + (φω) ² Step 27 for calculating RI and (RI) ² Step 28 for calculating ωLI and (ωLI) ² Step 29 for calculating the number of stator coils ² Step 29 for determining the number of stator coils Processing step 30 Current adjustment step 31 Current pattern 32 Current pattern 33 Current pattern 101 Table top plate 102 Guide 103 Coil support member 104 Linear motor coil 105 Movable magnet 106 Position detector 107 Counter unit 108 Servo controller 109 Phase switching controller 110 Current ann 111 Guide unit 112 Filter circuit 113 Multiplier

Claims (10)

A plurality of stators composed of multiphase coils, a mover composed of multipolar permanent magnets straddling at least one of the plurality of stators, and a position of the mover A linear motor control device comprising means for selecting a stator to be energized,
A current command generation unit that generates a current command using a speed command, a current detection unit that detects a current, and a voltage command that generates a voltage command so that the current detection value detected by the current detection unit matches the current command A current control unit that includes: a current control unit that performs integration; a position generation unit that integrates the speed command to generate an estimated position; and a voltage output unit that outputs a voltage using the voltage command and the estimated position; In the linear motor driving system, the current control device is connected to one stator and includes at least two current control devices.
A stator coil number discriminating section for discriminating the number of coils of the stator driving the mover using the speed command, the current command, the voltage command, and a motor constant;
A linear motor control device comprising: a current adjusting unit that adjusts a current value for driving the mover using the result of the coil number determining unit of the stator and the estimated position. A plurality of stators composed of multiphase coils, a mover composed of multipolar permanent magnets straddling at least one of the plurality of stators, and a position of the mover A linear motor control device comprising means for selecting a stator to be energized,
A current command generation unit that generates a current command using a speed command, a current detection unit that detects a current, and a voltage command that generates a voltage command so that the current detection value detected by the current detection unit matches the current command A current control unit that includes: a current control unit that performs integration; a position generation unit that integrates the speed command to generate an estimated position; and a voltage output unit that outputs a voltage using the voltage command and the estimated position; In the linear motor driving system, the current control device is connected to one stator and includes at least two current control devices.
Determining the number of coils of the stator driving the mover using the speed command, the current command, the voltage command, and a motor constant in the coil number determination unit of the stator;
A linear motor control method comprising: adjusting a magnitude of a current command by the current adjusting unit according to a result of determining the number of coils of the stator of the coil number determining unit of the stator and the estimated position.   The linear motor according to claim 1, wherein the stator coil number discriminating unit discriminates the number of stator coils driving the mover by using a current sensor signal instead of the current command. Control device.   3. The linear motor according to claim 2, wherein the stator coil number discriminating unit discriminates the number of coils of the stator driving the mover by using a current sensor signal instead of the current command. Control method. 2. The stator coil number discriminating unit discriminates the number of stator coils driving the mover using a speed feedback signal from a speed sensor instead of the speed command. Linear motor control device. 3. The stator coil number discriminating unit discriminates the number of stator coils driving the mover using a speed feedback signal from a speed sensor instead of the speed command. Linear motor control method. The stator coil number discrimination unit is:
N ² = {(R · I) ² + (ωL · I) ² } / {V1 ² −2 · V1 · φω + (φω) ² }
Where N is the number of coils driving the mover, I is a current command , R · I is a voltage drop due to resistance, ωL · I is a voltage drop due to inductance, V1 is a voltage command , and φω is fixed using an induced voltage. 2. The linear motor control device according to claim 1, wherein the number of coils of the child is obtained. The stator coil number discrimination unit is:
N ² = {(R · I) ² + (ωL · I) ² } / {V1 ² −2 · V1 · φω + (φω) ² }
Where N is the number of coils driving the mover, I is a current command, R · I is a voltage drop due to resistance, ωL · I is a voltage drop due to inductance, V1 is a voltage command, and φω is fixed using an induced voltage. 3. The linear motor control method according to claim 2, wherein the number of coils of the child is obtained. The linear motor control device according to claim 1, wherein the current adjusting unit changes the current amplitude in a ramp shape according to the estimated position. The linear motor control method according to claim 2, wherein the current adjustment unit changes the current amplitude in a ramp shape according to the estimated position.