JP2005269758A - Motor controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor controller for suppressing a deviation between two motors even if a current instruction can not be corrected due to a restriction of a hardware, hardly inducing a vibration even if a phase advancing adjustment for compensating two motors is failed, and easily adjusting motors. <P>SOLUTION: The motor controller uses two motors, drives a single movable member, and is provided with a shaft deviation compensating section 31 for inputting first and second speed instructions, creating a shaft deviation compensating speed instruction for compensating an operational deviation between the first and second motors, and compensating the first and second speed instructions. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a motor control apparatus that drives an electronic component mounting apparatus, a machine tool, an industrial robot, and the like, and more particularly, to a tandem drive technique for obtaining high response performance by synchronously driving one movable part with two motors.

As a conventional motor control device, the first and second motor control devices and a vibration suppression control device are provided. The two motor control devices receive the same position command from the host control device, and perform vibration suppression control. The apparatus adds a value obtained by multiplying the deviation by a constant and a value obtained by multiplying the value obtained by integrating the deviation by a constant based on the deviation between the speed feedback of the first motor control device and the speed feedback of the second motor control device. A current command correction value obtained by performing phase advance compensation on the calculated value, and adding the current command correction value to the current command of the first motor control device. There is a correction obtained by subtracting from the current command to suppress a shift between the two motors and obtain a high response (for example, see Patent Document 1).
JP 2001-273037 A

However, in the conventional motor control device, since only the current command values of the two motors are corrected, it cannot be used when the current command cannot be corrected due to hardware restrictions, and it can be corrected. However, since the current command affects the movement of the motor with high sensitivity, there is a problem that adjustment is difficult. In addition, in order to perform compensation between the two motors, the phase of the signal to be compensated is advanced, but there is also a problem that if this phase advance is misadjusted, vibration is induced.
The present invention has been made in view of such problems, and even when the current command cannot be corrected due to hardware restrictions, it is possible to suppress the mutual synchronization shift between the two motors, and between the two motors. A motor control device with improved responsiveness of synchronous control, which can suppress the phase shift between two motors even if a phase advance adjustment for performing compensation is wrong, makes it difficult to induce vibration and facilitates the adjustment. The purpose is to provide.

In order to solve the above problems, the present invention is configured as follows.
According to the first aspect of the present invention, the position command output from the host controller is set as the target position of the two motors, and the first speed control is calculated so that the first motor position matches the position command. A first speed control unit that performs speed control so that the first motor speed matches the first speed command and calculates a first torque or thrust command, and inputs the first torque or thrust command to generate torque or A first torque control unit that performs thrust control and drives the first motor; a first position detector that detects a position of the first motor; and a first difference that calculates the first motor speed from the first motor position. A second position control unit that calculates a second speed command so that the second motor position matches the position command, and performs speed control so that the second motor speed matches the second speed command. 2 torque or A second speed control unit that calculates a force command; a second torque control unit that inputs the second torque or thrust command and performs torque or thrust control to drive the second motor; and detects a position of the second motor In a motor control device comprising a second position detector and a second differentiator for calculating the second motor speed from the second motor position, and driving one movable member with two motors,
The first speed command and the second speed command are input, and an axis deviation compensation speed command for compensating for an operation deviation between the first motor and the second motor is created, and the first speed command and the second speed command are generated. An axis deviation compensation unit for compensating for the above is provided.

According to a second aspect of the present invention, the shaft misalignment compensation unit subtracts the second speed command from the first speed command to calculate a shaft speed command difference, and the shaft speed command difference. The value obtained by multiplying the time-integrated value by a constant, the inter-axis speed command difference integral value, the inter-axis speed command difference proportional value obtained by multiplying the constant by a constant, and the value obtained by time-differentiating the inter-axis speed command difference. A compensation arithmetic unit that outputs a value obtained by adding an inter-axis speed command difference differential value multiplied by the axis deviation compensation speed command, an adder that adds the axis deviation compensation speed command to the first speed command, and And a subtractor for subtracting the axis deviation compensation speed command from the second speed command.

In the first aspect of the present invention, the position command output from the host controller is set as the target position of the two motors, and the first speed command is calculated so that the first motor position matches the position command. A position control unit, a first speed control unit that calculates a first torque or thrust command by performing speed control so that the first motor speed matches the first speed command, and inputs the first torque or thrust command. A first torque controller for controlling the torque or thrust and driving the first motor; a first position detector for detecting the position of the first motor; and a first motor speed for calculating the first motor speed from the first motor position. 1 differentiator, a second position control unit that calculates a second speed command so that the second motor position matches the position command, and speed control so that the second motor speed matches the second speed command. Second torque Or a second speed control unit that calculates a thrust command, a second torque control unit that inputs the second torque or the thrust command and performs torque or thrust control to drive the second motor, and a position of the second motor. A motor control device comprising: a second position detector for detecting; and a second differentiator for calculating the second motor speed from the second motor position, wherein one movable member is driven by two motors.
The first motor speed and the second motor speed are inputted, an axis deviation compensation speed command for compensating for an operation deviation between the first motor and the second motor is created, and the first speed command and the second speed are created. An axis deviation compensation unit for compensating the command is provided.

  According to a fourth aspect of the present invention, the shaft misalignment compensation unit is configured to subtract the first motor speed from the second motor speed to calculate an inter-shaft speed difference, and to calculate the inter-shaft speed difference as a time. Inter-axis speed difference integral value obtained by multiplying the integrated value by a constant, inter-axis speed difference proportional value obtained by multiplying the inter-axis speed difference by a constant, and inter-axis speed obtained by multiplying the value obtained by time differentiation of the inter-axis speed difference by a constant. A compensation calculator for outputting a value obtained by adding the differential differential value as the axis deviation compensation speed command, an adder for adding the axis deviation compensation speed command to the first speed command, and the axis from the second speed command to the axis And a subtractor for subtracting the deviation compensation speed command.

According to a fifth aspect of the present invention, the position command output from the host controller is set as the target position of the two motors, and the first speed command is calculated so that the first motor position matches the position command. A position control unit, a first speed control unit that calculates a first torque or thrust command by performing speed control so that the first motor speed matches the first speed command, and inputs the first torque or thrust command. A first torque controller for controlling the torque or thrust and driving the first motor; a first position detector for detecting the position of the first motor; and a first motor speed for calculating the first motor speed from the first motor position. 1 differentiator, a second position control unit that calculates a second speed command so that the second motor position matches the position command, and speed control so that the second motor speed matches the second speed command. Second torque Or a second speed control unit that calculates a thrust command, a second torque control unit that inputs the second torque or the thrust command and performs torque or thrust control to drive the second motor, and a position of the second motor. A motor control device comprising: a second position detector for detecting; and a second differentiator for calculating the second motor speed from the second motor position, wherein one movable member is driven by two motors.
The first motor position and the second motor position are input, an axis deviation compensation speed command for compensating for an operation deviation between the first motor and the second motor is created, and the first speed command and the second speed command are generated. An axis deviation compensation unit for compensating for the above is provided.

According to a sixth aspect of the present invention, the position command output from the host controller is set as the target position of the two motors, and the first speed command is calculated so that the first motor position matches the position command. A position control unit, a first speed control unit that calculates a first torque or thrust command by performing speed control so that the first motor speed matches the first speed command, and inputs the first torque or thrust command. A first torque controller for controlling the torque or thrust and driving the first motor; a first position detector for detecting the position of the first motor; and a first motor speed for calculating the first motor speed from the first motor position. 1 differentiator, a second position control unit that calculates a second speed command so that the second motor position matches the position command, and speed control so that the second motor speed matches the second speed command. Second torque Or a second speed control unit that calculates a thrust command, a second torque control unit that inputs the second torque or the thrust command and performs torque or thrust control to drive the second motor, and a position of the second motor. A motor control device comprising: a second position detector for detecting; and a second differentiator for calculating the second motor speed from the second motor position, wherein one movable member is driven by two motors.
The first torque or thrust command and the second torque or thrust command, or the first motor speed command and the second motor speed command, or the first position command and the second position command as a first input signal pair. The first motor position and the second motor position are input as a second input signal pair, and a first dynamic signal model from the first input signal pair to the second input signal pair is used. An axis deviation compensation unit that calculates one prediction speed ΔPfb1p and second prediction speed ΔPfb2p and compensates for axis deviation using the first prediction speed ΔPfb1p and the second prediction speed ΔPfb2p is provided.

  Further, the invention according to claim 7 is characterized in that the axis misalignment compensation unit subtracts the first predicted speed from the second predicted speed to calculate an inter-axis predicted speed difference, and the inter-axis predicted speed difference. The time-integrated value is multiplied by a constant, and the inter-axis predicted speed difference integral value, the inter-axis predicted speed difference proportional value is multiplied by a constant, and the inter-axis predicted speed difference is time-differentiated. A compensation arithmetic unit that outputs a value obtained by adding an estimated inter-axis speed difference differential value multiplied by the axis deviation compensation speed command, an adder that adds the axis deviation compensation speed command to the speed command 1, and And a subtracter that subtracts from the speed command 2.

Further, in the invention according to claim 8, in the shaft misalignment compensation unit, the sampling cycle is Ts, ΔPfb1 ^* (i + m), the first torque or thrust command, the first speed command, and the first position command. Any one of the inputs u is used as an input u or its increment value Δu to the first motor position Pfb1 or its increment value ΔPfb1 using a discrete-time transfer function model, and a time (i + m) · Ts is the first motor predicted speed at Ts, Δ represents the increment value during the sampling period Ts, and M is the predicted section, the first predicted speed ΔPfb1p is
△ Pfb1p = △ Pfb1 ^* (i + M) or △ Pfb1p = △ Pfb1 ^* (i + M−1)
It is characterized by giving as.

According to the ninth aspect of the invention, when s1 and s2 are interpolation coefficients, the first predicted speed ΔPfb1p is replaced by ΔPfb1p = {s1 · ΔPfb1 ^* (i + M−1) + s2 · ΔPfb1 ^* (i + M)} / (s1 + s2)
Especially when M = 1 and the first motor speed ΔPfb1 (i) is obtained at the sampling time i · Ts,
ΔPfb1p ＝ {s1 ・ ΔPfb1 (i) + s2 ・ ΔPfb1 ^* (i + 1)} / (s1 + s2)
It is characterized by giving as.

In the invention according to claim 10, A _mn and B _mn are coefficients determined by a discrete time transfer function model from the input u to the first motor position Pfb1, Na and Nb are orders of the discrete time transfer function model, When the first motor position Pfb1 (i−K) in the past of K (≧ 0) sampling is input at the sampling time i · Ts, the m-destination first motor predicted speed ΔPfb1 ^* (i + m) is

ΔPfb1 ^* (i + m) = Pfb1 ^* (i + m)-Pfb1 ^* (i + m-1)
It is characterized by giving as.

In the invention according to claim 11, A _mn and B _mn are coefficients determined by the discrete time transfer function model from the input increment value Δu to the first motor speed ΔPfb1, and Na and Nb are the coefficients of the discrete time transfer function model. When the first motor position Pfb1 (i−K) past K (≧ 0) sampling is input at the sampling time i · Ts, the first motor predicted speed ΔPfb1 ^* (i + m) of the m sampling destination The

  It is characterized by giving as.

In the invention of claim 12, A _mn and B _mn are coefficients determined by a discrete time transfer function model from the input u to the first motor speed ΔPfb1, Na and Nb are orders of the discrete time transfer function model, When the first motor position Pfb1 (i−K) in the past of K (≧ 0) sampling is input at the sampling time i · Ts, the m-destination first motor predicted speed ΔPfb1 ^* (i + m) is

  It is characterized by giving as.

According to a thirteenth aspect of the present invention, in the shaft misalignment compensator, the sampling period is Ts, ΔPfb2 ^* (i + m), the second torque or thrust command, the second speed command, and the second position command. Any one of the inputs u is used as an input u or its increment value Δu to the second motor position Pfb2 or its increment value ΔPfb2 using a discrete time transfer function model. + m) · Ts is the second motor predicted speed at Ts, Δ is the increment value during the sampling period Ts, and M is the prediction interval, and at the sampling time i · Ts, K (≧ 0) 2 Using the motor position Pfb2 (i−K), the second predicted speed ΔPfb2p is
△ Pfb2p = △ Pfb2 ^* (i + M) or △ Pfb2p = △ Pfb2 ^* (i + M−1)
It is characterized by giving as.

Further, in the invention described in claim 14, when s1 and s2 are interpolation coefficients, the second predicted speed ΔPfb2p is replaced with the expression for obtaining ΔPfb2p in claim 13,
ΔPfb2p = {s1 ・ ΔPfb2 ^* (i + M−1) + s2 ・ ΔPfb2 ^* (i + M)} / (s1 + s2)
Especially when M = 1 and the second motor speed ΔPfb2 (i) is obtained at the sampling time i · Ts,
ΔPfb2p = {s1, ΔPfb2 (i) + s2, ΔPfb2 ^* (i + 1)} / (s1 + s2)
It is characterized by giving as.

In the invention described in claim 15, A _mn and B _mn are coefficients determined by a discrete time transfer function model from the input u to the second motor position Pfb2, and Na and Nb are orders of the discrete time transfer function model, When the second motor position Pfb2 (i−K) past K (≧ 0) sampling at the sampling time i · Ts is input, the second motor predicted speed ΔPfb2 ^* (i + m) of the m sampling destination is

ΔPfb2 ^* (i + m) = Pfb2 ^* (i + m)-Pfb2 ^* (i + m-1)
It is characterized by giving as.

In the invention described in claim 16, A _mn and B _mn are coefficients determined by a discrete time transfer function model from the input increment value Δu to the second motor speed ΔPfb2, and Na and Nb are the coefficients of the discrete time transfer function model. When the second motor position Pfb2 (i−K) past K (≧ 0) sampling is input at the sampling time i · Ts, the second motor predicted speed ΔPfb2 ^* (i + m) of the m sampling destination The

  It is characterized by giving as.

In the invention described in claim 17, A _mn and B _mn are coefficients determined by a discrete time transfer function model from the input u to the second motor speed ΔPfb2, and Na and Nb are orders of the discrete time transfer function model, When the second motor position Pfb2 (i−K) past K (≧ 0) sampling at the sampling time i · Ts is input, the second motor predicted speed ΔPfb2 ^* (i + m) of the m sampling destination is

  It is characterized by giving as.

Since the present invention corrects the speed command, even if the current command cannot be corrected due to hardware restrictions, mutual synchronization deviation between the two motors can be suppressed. Further, according to claim 6, since the phase of the signal is not simply advanced, but the phase is advanced by prediction using the dynamic characteristic model of the controlled object, the mutual phase shift between the two motors is suppressed, Vibrations are less likely to be induced and adjustment can be facilitated, and the responsiveness of synchronous control can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Although various functions and means are built in the actual motor control device, only the functions and means related to the present invention will be described and described in the figure. Hereinafter, the same reference numerals are assigned to the same names as much as possible, and the duplicate description is omitted.

FIG. 1 is a block diagram of a motor control apparatus for explaining a first embodiment to which the present invention is applied. In FIG. 1, 11 is a command generator, 12 is a first position controller, 13 is a first speed controller, 14 is a first torque controller, 15 is a first differentiator, 16 is a first motor, and 17 is a first motor. 1 position detector, 18 a table, 22 a second position control unit, 23 a second speed control unit, 24 a second torque control unit, 25 a second differentiator, 26 a second motor, 27 a second A position detector, 31 is an axis deviation compensation unit, 32 is a subtractor, 33 is a compensation calculator, 34 is an adder, and 35 is a subtractor.
The command generation unit 11 outputs a position command Pref to the first position control unit 12 and the second position control unit 22. The first position control unit 12 inputs the position command Pref and the first motor position Pfb1, and outputs the first speed command Vref1 to the subtracter 32 and the adder 34. The adder 34 inputs the first speed command Vref1 and the axis deviation compensation speed command Cvref, and outputs a signal obtained by adding the two input commands to the first speed control unit 13 as a new speed command. The first speed control unit 13 receives the signal from the adder 34 and the first motor speed Vfb1, and outputs a first torque command Tref1 to the first torque control unit 14. The first torque control unit 14 receives the first torque command Tref1 and outputs a first motor drive current to the first motor 16. The first motor 16 receives the first motor driving current, generates torque, and drives the table 18. A first position detector 17 is attached to the first motor 16, detects the position of the first motor, and outputs the first motor position Pfb 1 to the first position controller 12 and the first differentiator 15. To do. The first differentiator 15 receives the first motor position Pfb1 and outputs the first motor speed Vfb1 to the first speed control unit 13.

The second position control unit 22 inputs the position command Pref and the second motor position Pfb2, and outputs the second speed command Vref2 to the subtracter 32 and the subtractor 35. The subtractor 35 receives the second speed command Vref2 and the previous axis deviation compensation speed command Cvref, and uses the signal obtained by subtracting the axis deviation compensation speed command Cvref from the second speed command Vref2 as a new speed command. To the unit 23. The second speed control unit 23 receives the signal from the subtractor 35 and the second motor speed Vfb2, and outputs a second torque command Tref2 to the second torque control unit 24. The second torque control unit 24 receives the second torque command Tref2 and outputs a second motor driving current to the second motor 26. The second motor 26 inputs the second motor driving current, generates torque, and drives the table 18. A second position detector 27 is attached to the second motor 26, detects the position of the second motor, and outputs the second motor position Pfb2 to the second position controller 22 and the second subtractor 25. To do. The second subtractor 25 receives the second motor position Pfb2 and outputs the second motor speed Vfb2 to the second speed controller 23.
The subtractor 32 inputs the first speed command Vref1 and the second speed command Vref2, and outputs an inter-axis speed command difference obtained by subtracting the second speed command Vref2 from the first speed command Vref1 to the compensation calculator 33. . The compensation calculator 33 inputs an inter-axis speed command difference obtained by subtracting the second speed command Vref2 from the first speed command Vref1, and outputs the axis deviation compensated speed command Cvref to the adder 34 and the subtractor 35.
The table 18 is driven by the first motor 16 and the second motor 26 by combining a movable part driven by the first motor and a movable part driven by the second motor by this table. The movable part driven by the motor means a table driven by a ball screw or the like when the motor is a rotary type, and means a table coupled to the mover when the motor is a linear type.

The command generator 11 generates a position command Pref that is a target position of the table 18.
The first position control unit 12 performs a position control calculation so that the first motor position Pfb1 matches the position command Pref, and calculates the first speed command Vref1. The first speed control unit 13 performs a speed control calculation so that the first motor speed Vfb1 coincides with a signal obtained by adding the first speed command Vref1 and the compensation value Cvref, and the first torque command Tref1 is calculated. calculate. The first torque control unit 14 performs a torque control calculation based on the first torque command Tref1, and calculates the first motor drive current. The first differentiator 15 calculates the first motor speed Vfb1 from the first motor position Pfb1.
The second position control unit 22 performs a position control calculation so that the second motor position Pfb2 matches the position command Pref, and calculates the second speed command Vref2. The second speed control unit 23 performs a speed control calculation so that the second motor speed Vfb2 matches a signal obtained by subtracting the compensation value Cvref from the second motor speed command Vref2, and calculates the second torque command Tref2. . The second torque control unit 24 performs a torque control calculation based on the second torque command Tref2, and calculates the second motor drive current. The second subtractor 25 calculates the second motor speed Vfb2 from the second motor position Pfb2.
The compensation calculator 33 performs a compensation calculation so that an inter-axis speed command difference obtained by subtracting the second speed command Vref2 from the first speed command Vref1 is zero, and calculates the axis deviation compensated speed command Cvref.
The axis deviation compensation unit 31 includes a subtracter 32, an adder 34, a subtracter 35, and a compensation calculator 33. That is, in FIG. 1, the portion surrounded by the broken line is the axis deviation compensation unit 31.
In this way, the table 18 is driven by the first motor 16 and the second motor 26 so that the first motor 16 and the second motor 26 are not misaligned.
In this embodiment, the output of the speed control unit is a torque command assuming a rotary motor, but in the case of a linear motor, the output of the speed control unit may be realized with the same configuration as the thrust command.

FIG. 2 is a block diagram illustrating details of the compensation calculator 33. In FIG. 2, 41 is a differentiator, 42 is a multiplier, 43 is an integrator, 44 is a multiplier, 45 is a multiplier, and 46 is an adder.
The subtractor 32 inputs the first speed command Vref1 and the second speed command Vref2, and outputs the inter-axis speed command difference to the differentiator 41, the integrator 43, and the multiplier 45. The differentiator 41 receives the inter-axis speed command difference, performs time differentiation, and outputs a value obtained by time-differentiating the inter-axis speed command difference to the multiplier 42. The multiplier 42 inputs a value obtained by time differentiation of the speed command difference between the axes, and outputs a value obtained by multiplying a preset constant Gd to the adder 46. The integrator 43 inputs the speed command difference between the axes, performs time integration, and outputs a value obtained by time integration of the speed command difference between the axes to the multiplier 44. The multiplier 44 inputs a value obtained by integrating the speed command difference between the axes with time, and outputs a value obtained by multiplying a preset constant Gi to the adder 46. The multiplier 45 inputs the speed command difference between the axes and outputs a value obtained by multiplying a preset constant Gp to the adder 46. The adder 46 inputs the inter-axis speed command difference differential value, the inter-axis speed command difference integral value, and the inter-axis speed command difference proportional value, and the inter-axis speed command difference differential value and the inter-axis speed command difference. The integral value and the inter-axis speed command difference proportional value are added together and output as an axis deviation compensated speed command Cvref.
In the figure, a portion surrounded by a broken line is the compensation calculator 33.

Next, the result of verifying the effect of Example 1 using simulation will be described with reference to FIGS. FIG. 7 shows a response example in the case where compensation for the axis deviation is not performed, and FIG. 8 shows a response example in the first embodiment. 7A shows the position command increment value Vr1 for the first axis, the motor speed Vfb1, and the speed deviation Ve1, and FIG. 7B shows the position command increment value Vr2 for the second axis, the motor speed Vfb2, and The speed deviation Ve2 is shown, and FIG. 7C shows the synchronous position error Se between the two axes.
Similarly, FIG. 8A shows the position command increment value Vr1 for the first axis, the motor speed Vfb1, and the speed deviation Ve1, and FIG. 8B shows the position command increment value Vr2 for the second axis and the motor speed. Vfb2 and speed deviation Ve2 are shown, and FIG. 8C shows the synchronous position error Se between the two axes. Comparing the synchronization position errors between the two axes shown in FIG. 7C and FIG. 8C, an error of about 200 pulses is obtained when compensation between the axes is not performed, and Example 1 was used. In this case, it is about 80 pulses, and the synchronization error is reduced to 1/2 or less.
By adopting the above configuration, the difference in response between the first axis and the second axis can be eliminated, and the axis deviation caused by the difference in response between the first motor and the second motor can be suppressed. A certain table can be driven at high speed and high accuracy. Further, vibration can be suppressed.

The second embodiment is different from the first embodiment in that the compensation calculator 33 uses the difference in speed between axes command command Cvref obtained by subtracting the second speed command Vref2 from the first speed command Vref1 in the first embodiment. In contrast, in the second embodiment, the axis deviation compensation speed command Cvref is calculated using the inter-axis speed difference obtained by subtracting the first motor speed Vfb1 from the second motor speed Vfb2.
FIG. 3 is a block diagram of a motor control apparatus for explaining a second embodiment to which the present invention is applied. Here, only points in which FIG. 3 is different from FIG.
In FIG. 3, the first position control unit 12 outputs the first speed command Vref1 only to the adder 34. Further, the second position control unit 22 outputs the second speed command Vref2 only to the subtractor 35.
The first differentiator 15 outputs the first motor speed Vfb1 to the first speed controller 13 and the subtracter 32. The second subtractor 25 outputs the second motor speed Vfb2 to the second speed controller 23 and the subtracter 32.
The subtractor 32 receives the first motor speed Vfb1 and the second motor speed Vfb2, and outputs the difference between the shaft speeds obtained by subtracting the first motor speed Vfb1 from the second motor speed Vfb2 to the compensation calculator 33. The compensation calculator 33 receives the speed difference between the axes, and calculates an axis deviation compensation speed command Cvref based on the speed difference between the axes.

The shaft misalignment compensator 31 receives the first motor position Pfb1 and the second motor position Pfb2, calculates the first motor speed Vfb1 from the first motor position Pfb1, and calculates the second motor speed Vfb2 from the second motor position Pfb2. And an inter-axis speed difference obtained by subtracting the first motor speed Vfb1 from the second motor speed Vfb2 may be output to the compensation calculator 33.
Further, the compensation calculator 33 may calculate the axis deviation compensation speed command Cvref based on the inter-axis position difference obtained by subtracting the first motor position Pfb1 from the second motor position Pfb2.
Alternatively, the inter-axis speed difference may be calculated from the difference between the inter-axis position differences, and the axis deviation compensation speed command Cvref may be calculated based on the inter-axis speed difference.

FIG. 4 is a block diagram illustrating details of the compensation calculator 33 in the second embodiment.
The compensation calculator 33 of the second embodiment is different from the compensation calculator 33 of the first embodiment in that the compensation calculator 33 calculates the axis deviation compensation speed command Cvref based on the inter-axis speed command difference in the first embodiment. In the second embodiment, the axis deviation compensation speed command Cvref is calculated based on the speed difference between the axes.
In the figure, a portion surrounded by a broken line is the compensation calculator 33.

  The third embodiment is different from the first embodiment in that in the first embodiment, the compensation calculator 33 uses the inter-axis speed command difference obtained by subtracting the second speed command Vref2 from the first speed command Vref1 to obtain the axis deviation compensation speed command Cvref. In contrast to this, in the third embodiment, the first deviation predictor 36 for calculating the first predicted speed ΔPfb1p based on the first speed command Vref1 and the first motor position Pfb1 in the shaft misalignment compensation unit 31, and the second speed command Vref2 And a second predictor 37 that calculates a second predicted speed ΔPfb2p based on the second motor position Pfb2, and a compensation calculator 33 uses the first predicted speed ΔPfb1p and the second predicted speed ΔPfb2p to compensate for an axis deviation. This is the point at which the speed command Cvref is calculated.

FIG. 5 is a block diagram of a motor control apparatus for explaining a third embodiment to which the present invention is applied. Here, only points in which FIG. 5 is different from FIG. 1 will be described in order to avoid redundant description.
In FIG. 5, 36 is a first predictor and 37 is a second predictor. The first position control unit 12 outputs the first speed command Vref1 to the adder 34 and the first predictor 36. Further, the second position control unit 22 outputs the second speed command Vref2 to the subtractor 35 and the second predictor 37.
The first position detector 17 outputs the first motor position Pfb1 to the first position control unit 12, the first differentiator 15, and the first predictor 36. The second position detector 27 outputs the second motor position Pfb2 to the second position control unit 22, the second differentiator 25, and the second predictor 37.
The first predictor 36 receives the first speed command Vref1 and the first motor position Pfb1, and outputs the first predicted speed ΔPfb1p to the subtractor 32. The second predictor 37 receives the second speed command Vref2 and the second motor position Pfb2, and outputs the second predicted speed ΔPfb2p to the subtractor 32.
The subtractor 32 receives the first predicted speed ΔPfb1p and the second predicted speed ΔPfb2p, and outputs the inter-axis predicted speed difference obtained by subtracting the first predicted speed ΔPfb1p from the second predicted speed ΔPfb2p to the compensation calculator 33. The compensation calculator 33 receives the inter-axis predicted speed difference and calculates an axis deviation compensated speed command Cvref based on the inter-axis predicted speed difference.
The first predictor 36 calculates a first predicted speed ΔPfb1p based on the first speed command Vref1 and the first motor position Pfb1. The second predictor 37 calculates a second predicted speed ΔPfb2p based on the second speed command Vref2 and the second motor position Pfb2.
Instead of the first motor speed command Vref1 input to the first predictor in FIG. 5, the first torque command Tref1 or the position command Pref may be input to the first predictor. Similarly, the second torque command Tref2 or the position command Pref may be input to the second predictor instead of the second motor speed command Vref2 input to the second predictor.

Next, a method for calculating the first predicted speed ΔPfb1p will be described.
In this control apparatus, when the sampling period is Ts and the first motor position Pfb1 (iK) in the past of K (≧ 0) sampling at the sampling time i · Ts is input from the first position detector, the time i · Ts Using the predicted value ΔPfb1 ^* (i + m) of the first motor speed at m sampling destination time (i + m) · Ts, the predicted value ΔPfb1p is expressed by equation (1).

ΔPfb1p = ΔPfb1 ^* (i + M) or ΔPfb1p = ΔPfb1 ^* (i + M−1) (1)

  Or, the equation (2)

ΔPfb1p = {s1 ・ ΔPfb1 ^* (i + M−1) + s2 ・ ΔPfb1 ^* (i + M)} / (s1 + s2) (2)

Can also be given. Here, M is a prediction interval, and s1 and s2 are interpolation coefficients.
Especially when K = 0 and M = 1, formula (3)

ΔPfb1p = {s1 ・ ΔPfb1 (i) + s2 ・ ΔPfb1 ^* (i + 1)} / (s1 + s2) (3)

Given in. Here, Δ represents an increment value during the sampling period Ts.
Here, the first motor predicted speed ΔPfb1 ^* (i + m) of m sampling destinations is expressed by the following equations (4) and (5).

ΔPfb1 ^* (i + m) = Pfb1 ^* (i + m) −Pfb1 ^* (i + m−1) (5)

Or, it is given by one of the following two formulas.

  Hereinafter, Formula (4)-Formula (7) are demonstrated. First, equation (4) will be described. Now, the first torque command Tref1, the first speed command Vref1 or the position command Pref of the first motor 16 is considered as an input u, and the transmission from this input u (i) to the first motor position Pfb1 (i). The function model is

Gry (z) = (b ₁ z ⁻¹ +... + B _Nb z ^−Nb ) / (1−a ₁ z ^{−1 −...} −a _Na z ^−Na ) (8)

Is obtained in a discrete time system. At time i · Ts (hereinafter referred to as time i for convenience), assuming that the future input is u (j) = u (i) (j> i), the first motor position after time i−K is predicted, 4), and the coefficients A _mn and B _mn are given by the following equations.

However, a _n = 0 (n> Na), b _n = 0 (n <1 and n> Nb), a ' _{m (Na + K)} = 0, b' _{m (Nb + K)} = 0
Next, equation (6) will be described. Discrete time transfer function model from input increment value Δu (i) to first motor speed ΔPfb1 (i)

Gdd (z) = (b ₁ z ⁻¹ +… + b _Nb z ^−Nb ) / (1-a ₁ z ^−1- …-a _Na z ^−Na ) (11)

When the future input is u (j) = u (i) (j> i) at time i and the first motor speed after time i−K is predicted, the above equation (6) is obtained. Here, the coefficients A _mn and B _mn are given by the following equations.

Where a _n = 0 (n> Na), b _n = 0 (n <1 and n> Nb)
Furthermore, Formula (7) is demonstrated. Discrete time transfer function model from input u (i) to first motor speed ΔPfb1 (i)

Grd (z) = (b ₁ z ⁻¹ +… + b _Nb z ^−Nb ) / (1-a ₁ z ^−1- …-a _Na z ^−Na ) (13)

When the future input is u (j) = u (i) (j> i) at time i and the first motor speed after time i−K is predicted, the above equation (7) is obtained. Here, the coefficients A _mn and B _mn are given by the following equations.

Where a _n = 0 (n> Na), b _n = 0 (n <1 and n> Nb)

Next, a method for calculating the second predicted speed ΔPfb2p will be described.
In this control apparatus, when the sampling cycle is Ts and the second motor position Pfb2 (iK) in the past of K (≧ 0) sampling at the sampling time i · Ts is input from the second position detector, the time i · Ts Using the predicted value ΔPfb2 ^* (i + m) of the second motor speed at the time (i + m) · Ts of m sampling destinations, the predicted value ΔPfb2p is expressed by the following equation (15).

ΔPfb2p = ΔPfb2 ^* (i + M) or ΔPfb2p = ΔPfb2 ^* (i + M−1) (15)

  Or, interpolate to equation (16)

ΔPfb2p = {s1 ・ ΔPfb2 ^* (i + M−1) + s2 ・ ΔPfb2 ^* (i + M)} / (s1 + s2) (16)

Can also be given. Here, M is a prediction interval, and s1 and s2 are interpolation coefficients.
Especially when K = 0 and M = 1, the equation (17)

ΔPfb2p = {s1 ・ ΔPfb2 (i) + s2 ・ ΔPfb2 ^* (i + 1)} / (s1 + s2) (17)

Given in. Here, Δ represents an increment value during the sampling period Ts.
Here, the second motor predicted speed ΔPfb2 ^* (i + m) of m sampling destinations is expressed by the following equations (18) and (19).

ΔPfb2 ^* (i + m) = Pfb2 ^* (i + m) −Pfb2 ^* (i + m−1) (19)

Or, it is given by one of the following two formulas.

Hereinafter, Formula (18)-Formula (21) are demonstrated. First, equation (18) will be described. Now, any one of the second torque command Tref2, the second speed command Vref2 or the position command Pref of the second motor 26 is considered as an input u, and transmission from this input u (i) to the second motor position Pfb2 (i). It is assumed that the function model is obtained in the discrete time system of Expression (8). At time i · Ts (hereinafter referred to as time i for convenience), assuming that the future input is u (j) = u (i) (j> i), the second motor position after time i−K is predicted, 18), and the coefficients A _mn and B _mn are given by the equations (9) and (10).

Next, equation (20) will be described. Now, using the discrete time transfer function model from the input increment value Δu (i) to the second motor speed ΔPfb2 (i), equation (11), the future input is represented by u (j) = u (i) ( When j> i), the second motor speed after time i-K is predicted, the equation (20) is obtained. Here, the coefficients A _mn and B _mn are given by Expression (12).
Furthermore, Formula (21) is demonstrated. Now, using the discrete time transfer function model from the input u (i) to the second motor speed ΔPfb2 (i), equation (13), the future input at time i is u (j) = u (i) (j> As i), when the second motor speed after the time i−K is predicted, the equation (21) is obtained. Here, the coefficients A _mn and B _mn are given by equation (14).

FIG. 6 is a block diagram illustrating details of the compensation calculator 33 in the third embodiment.
The compensation calculator 33 of the third embodiment is different from the compensation calculator 33 of the first embodiment in that the compensation calculator 33 calculates the axis deviation compensation speed command Cvref based on the inter-axis speed command difference in the first embodiment. In the third embodiment, the axis deviation compensation speed command Cvref is calculated based on the inter-axis predicted speed difference.
In the figure, a portion surrounded by a broken line is the compensation calculator 33.

  As described above, when the speed command of both axes is obtained, the method according to claim 1 is applied, and when the motor speed of both axes is obtained, the method according to claim 2 and the position of both axes are obtained. Can be obtained, the control apparatus having high responsiveness can be provided by suppressing the mutual displacement between the axes by using the method according to claim 5 or 6.

  The present invention provides positioning control servo control devices for electronic component mounting devices and semiconductor manufacturing devices, motor control devices for driving machine tools and industrial robots, and tandem drive control for synchronously driving one movable part with two motors. Available.

The block diagram of the motor control apparatus explaining the 1st example to which the present invention is applied. 1 is a block diagram for explaining a compensation computing unit according to a first embodiment to which the present invention is applied. The block diagram of the motor control apparatus explaining the 2nd example to which the present invention is applied. Block diagram for explaining a compensation arithmetic unit according to a second embodiment to which the present invention is applied The block diagram of the motor control apparatus explaining the 3rd example to which the present invention is applied. Block diagram for explaining a compensation arithmetic unit according to a third embodiment to which the present invention is applied Response example when compensation for axis deviation is not performed Response example of Embodiment 1 of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Command generation part 12 1st position control part 13 1st speed control part 14 1st torque control part 15 1st differentiator 16 1st motor 17 1st position detector 18 Table 22 2nd position control part 23 2nd speed control Unit 24 second torque control unit 25 second difference unit 26 second motor 27 second position detector 31 axis deviation compensation units 32 and 35 subtractor 33 compensation calculators 34 and 46 adder 36 first predictor 37 second prediction Differentiator 41 Differentiator 42, 44, 45 Multiplier 43 Integrator

Claims (17)

The position command output from the host controller is set as the target position of the two motors, the first position control unit that calculates the first speed command so that the first motor position matches the position command, and the first speed command A first speed control unit that performs speed control so as to match the first motor speed and calculates a first torque or thrust command, and inputs the first torque or thrust command, performs torque or thrust control, and drives the first motor A first torque controller, a first position detector for detecting a position of the first motor, a first differentiator for calculating the first motor speed from the first motor position, and a second in response to the position command. A second position control unit that calculates a second speed command so that the motor position matches, and a second torque or thrust command that performs speed control so that the second motor speed matches the second speed command. 2nd speed A control unit; a second torque control unit that inputs the second torque or thrust command and performs torque or thrust control to drive the second motor; a second position detector that detects a position of the second motor; A motor control device including a second subtractor for calculating the second motor speed from a second motor position and driving one movable member by two motors;
The first speed command and the second speed command are input, and an axis deviation compensation speed command for compensating for an operation deviation between the first motor and the second motor is created, and the first speed command and the second speed command are generated. A motor control device comprising: an axis deviation compensation unit for compensating   The axis deviation compensation unit includes a subtracter that subtracts the second speed command from the first speed command to calculate an inter-axis speed command difference, and an axis obtained by multiplying a value obtained by time-integrating the inter-axis speed command difference with a constant. Inter-speed command difference integral value obtained by multiplying the inter-axis speed command difference by a constant, and an inter-axis speed command difference proportional value obtained by multiplying a value obtained by time-differentiating the inter-axis speed command difference by a constant, and A compensation arithmetic unit that outputs a value obtained by adding the axis deviation compensation speed command, an adder that adds the axis deviation compensation speed command to the first speed command, and the axis deviation compensation speed command from the second speed command. The motor control device according to claim 1, further comprising a subtractor that subtracts. The position command output from the host controller is set as the target position of the two motors, the first position control unit that calculates the first speed command so that the first motor position matches the position command, and the first speed command A first speed control unit that performs speed control so as to match the first motor speed and calculates a first torque or thrust command, and inputs the first torque or thrust command, performs torque or thrust control, and drives the first motor A first torque controller, a first position detector for detecting a position of the first motor, a first differentiator for calculating the first motor speed from the first motor position, and a second in response to the position command. A second position control unit that calculates a second speed command so that the motor position matches, and a second torque or thrust command that performs speed control so that the second motor speed matches the second speed command. 2nd speed A control unit; a second torque control unit that inputs the second torque or thrust command and performs torque or thrust control to drive the second motor; a second position detector that detects a position of the second motor; A motor control device including a second subtractor for calculating the second motor speed from a second motor position and driving one movable member by two motors;
The first motor speed and the second motor speed are inputted, an axis deviation compensation speed command for compensating for an operation deviation between the first motor and the second motor is created, and the first speed command and the second speed are created. A motor control device comprising an axis deviation compensation unit for compensating a command.   The shaft misalignment compensator includes a subtractor for subtracting the first motor speed from the second motor speed to calculate an inter-shaft speed difference, and an inter-shaft speed obtained by multiplying a value obtained by time-integrating the inter-shaft speed difference by a constant. A value obtained by adding a difference integral value, an inter-axis speed difference proportional value obtained by multiplying the inter-axis speed difference by a constant, and an inter-axis speed difference differential value obtained by multiplying the value obtained by time-differentiating the inter-axis speed difference by the constant. A compensation calculator for outputting an axis deviation compensation speed command; an adder for adding the axis deviation compensation speed command to the first speed command; and a subtractor for subtracting the axis deviation compensation speed command from the second speed command. The motor control device according to claim 3. The position command output from the host controller is set as the target position of the two motors, the first position control unit that calculates the first speed command so that the first motor position matches the position command, and the first speed command A first speed control unit that performs speed control so as to match the first motor speed and calculates a first torque or thrust command, and inputs the first torque or thrust command, performs torque or thrust control, and drives the first motor A first torque controller, a first position detector for detecting a position of the first motor, a first differentiator for calculating the first motor speed from the first motor position, and a second in response to the position command. A second position control unit that calculates a second speed command so that the motor position matches, and a second torque or thrust command that performs speed control so that the second motor speed matches the second speed command. 2nd speed A control unit; a second torque control unit that inputs the second torque or thrust command and performs torque or thrust control to drive the second motor; a second position detector that detects a position of the second motor; A motor control device including a second subtractor for calculating the second motor speed from a second motor position and driving one movable member by two motors;
The first motor position and the second motor position are input, an axis deviation compensation speed command for compensating for an operation deviation between the first motor and the second motor is created, and the first speed command and the second speed command are generated. A motor control device comprising: an axis deviation compensation unit for compensating The position command output from the host controller is set as the target position of the two motors, the first position control unit that calculates the first speed command so that the first motor position matches the position command, and the first speed command A first speed control unit that performs speed control so as to match the first motor speed and calculates a first torque or thrust command, and inputs the first torque or thrust command, performs torque or thrust control, and drives the first motor A first torque controller, a first position detector for detecting a position of the first motor, a first differentiator for calculating the first motor speed from the first motor position, and a second in response to the position command. A second position control unit that calculates a second speed command so that the motor position matches, and a second torque or thrust command that performs speed control so that the second motor speed matches the second speed command. 2nd speed A control unit; a second torque control unit that inputs the second torque or thrust command and performs torque or thrust control to drive the second motor; a second position detector that detects a position of the second motor; A motor control device including a second subtractor for calculating the second motor speed from a second motor position and driving one movable member by two motors;
The first torque or thrust command and the second torque or thrust command, or the first motor speed command and the second motor speed command, or the first position command and the second position command as a first input signal pair. The first motor position and the second motor position are input as a second input signal pair, and a first dynamic signal model from the first input signal pair to the second input signal pair is used. A motor control device comprising: an axis deviation compensation unit that calculates one prediction speed ΔPfb1p and a second prediction speed ΔPfb2p and compensates for an axis deviation using the first prediction speed ΔPfb1p and the second prediction speed ΔPfb2p.   The axis deviation compensation unit includes a subtracter that calculates an inter-axis predicted speed difference by subtracting the first predicted speed from the second predicted speed, and an axis obtained by multiplying a value obtained by time-integrating the inter-axis predicted speed difference. The inter-predicted speed difference integral value, the inter-axis predicted speed difference proportional value multiplied by a constant, and the inter-axis predicted speed difference proportional value multiplied by a constant to the inter-axis predicted speed difference differential value, A compensation arithmetic unit that outputs a value obtained by adding the axis deviation compensation speed command, an adder that adds the axis deviation compensation speed command to the speed command 1, and a subtractor that subtracts the speed command 2 from the speed command 2. The motor control device according to claim 6. In the axis deviation compensation unit, the sampling cycle is Ts, ΔPfb1 ^* (i + m) is any one of the first torque or thrust command, the first speed command, and the first position command as input u. First motor predicted speed at time (i + m) · Ts m sampling ahead of time i · Ts predicted using discrete time transfer function model from incremental value Δu to first motor position Pfb1 or its incremental value ΔPfb1 And Δ represents an increment value during the sampling period Ts, and M is a prediction interval, the first predicted speed ΔPfb1p is
△ Pfb1p = △ Pfb1 ^* (i + M) or △ Pfb1p = △ Pfb1 ^* (i + M−1)
The motor control device according to claim 6, which is given as: When s1 and s2 are interpolation coefficients, the first predicted speed ΔPfb1p is replaced by ΔPfb1p = {s1 · ΔPfb1 ^* (i + M−1) + s2 · ΔPfb1 ^* (i + M)} / (s1 + s2)
Especially when M = 1 and the first motor speed ΔPfb1 (i) is obtained at the sampling time i · Ts,
ΔPfb1p ＝ {s1 ・ ΔPfb1 (i) + s2 ・ ΔPfb1 ^* (i + 1)} / (s1 + s2)
The motor control device according to claim 8, wherein the motor control device is given as: A _mn and B _mn are coefficients determined by the discrete time transfer function model from the input u to the first motor position Pfb1, Na and Nb are the orders of the discrete time transfer function model, and K (≧ 0) at the sampling time i · Ts When the first motor position Pfb1 (i−K) in the past of sampling is input, the first motor predicted speed ΔPfb1 ^* (i + m) of the m sampling destination is

ΔPfb1 ^* (i + m) = Pfb1 ^* (i + m)-Pfb1 ^* (i + m-1)
The motor control device according to claim 8, wherein the motor control device is provided as: A _mn and B _mn are coefficients determined by the discrete time transfer function model from the input increment value Δu to the first motor speed ΔPfb1, Na and Nb are the orders of the discrete time transfer function model, and at the sampling time i · Ts, K ( ≧ 0) When the first motor position Pfb1 (i−K) in the past of sampling is input, the first motor predicted speed ΔPfb1 ^* (i + m) of the m sampling destination is

The motor control device according to claim 8, wherein the motor control device is provided as: A _mn and B _mn are coefficients determined by the discrete time transfer function model from the input u to the first motor speed ΔPfb1, Na and Nb are the orders of the discrete time transfer function model, and K (≧ 0) at the sampling time i · Ts When the first motor position Pfb1 (i−K) in the past of sampling is input, the first motor predicted speed ΔPfb1 ^* (i + m) of the m sampling destination is

The motor control device according to claim 8, wherein the motor control device is provided as: In the axis deviation compensation unit, the sampling cycle is Ts, ΔPfb2 ^* (i + m), the second torque or thrust command, the second speed command, or the second position command is used as an input u. Second motor predicted speed at time (i + m) · Ts m sampling ahead of time i · Ts predicted using discrete time transfer function model from incremental value Δu to second motor position Pfb2 or its incremental value ΔPfb2 And Δ represents the increment value during the sampling period Ts, and M is the prediction interval, the second motor position Pfb2 (i−K) in the past of K (≧ 0) sampling is used at the sampling time i · Ts. The second predicted speed ΔPfb2p is
△ Pfb2p = △ Pfb2 ^* (i + M) or △ Pfb2p = △ Pfb2 ^* (i + M−1)
The motor control device according to claim 6, which is given as: When s1 and s2 are interpolation coefficients, instead of the equation for obtaining ΔPfb2p in claim 13, the second predicted speed ΔPfb2p is:
ΔPfb2p = {s1 ・ ΔPfb2 ^* (i + M−1) + s2 ・ ΔPfb2 ^* (i + M)} / (s1 + s2)
Especially when M = 1 and the second motor speed ΔPfb2 (i) is obtained at the sampling time i · Ts,
ΔPfb2p = {s1, ΔPfb2 (i) + s2, ΔPfb2 ^* (i + 1)} / (s1 + s2)
The motor control device according to claim 13, which is given as: A _mn and B _mn are coefficients determined by the discrete time transfer function model from the input u to the second motor position Pfb2, Na and Nb are the orders of the discrete time transfer function model, and K (≧ 0) at the sampling time i · Ts When the second motor position Pfb2 (i−K) in the past of sampling is input, the second motor predicted speed ΔPfb2 ^* (i + m) of the m sampling destination is

ΔPfb2 ^* (i + m) = Pfb2 ^* (i + m)-Pfb2 ^* (i + m-1)
The motor control device according to claim 13 or 14, characterized by being given as: A _mn and B _mn are coefficients determined by the discrete time transfer function model from the input increment value Δu to the second motor speed ΔPfb2, Na and Nb are the orders of the discrete time transfer function model, and at the sampling time i · Ts, K ( ≧ 0) When the second motor position Pfb2 (i−K) in the past of sampling is input, the second motor predicted speed ΔPfb2 ^* (i + m) of the m sampling destination is

The motor control device according to claim 13 or 14, characterized by being given as: A _mn and B _mn are coefficients determined by the discrete time transfer function model from the input u to the second motor speed ΔPfb2, Na and Nb are the orders of the discrete time transfer function model, and K (≧ 0) at the sampling time i · Ts When the second motor position Pfb2 (i−K) in the past of sampling is input, the second motor predicted speed ΔPfb2 ^* (i + m) of the m sampling destination is

The motor control device according to claim 13 or 14, characterized by being given as: