JP2010178510A - Motor synchronization control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a motor synchronization control device which can maintain synchronization of each shaft with high accuracy, even if limits are imposed to a control input of each shaft. <P>SOLUTION: The motor synchronization control device is such that the control device includes a formation amount synchronizing section 4a which uses, as an input, a position correction amount for correcting a position difference of own shaft motor which is the difference between a position command, which is generated by each of two or more motor drive control devices individually driving the two or more shafts and is common to each shaft, and a position detection value detected by own shaft motor, and selects a position correction amount which is the latest in responsiveness from between two or more position correction amounts as a synchronization post-position correction amount; and each of the two or more motor drive control devices calculates a control input to own shaft motor, by using a corrected position difference which is obtained by subtracting the synchronization post-position correction amount from the position difference of own shaft. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a motor synchronous control device that performs synchronous control of position and speed of the servo motor or the like between two or more motor drive control devices that individually drive and control two or more servo motors.

  In general, when two or more motor drive control devices that drive and control a servo motor used to drive a machine tool are aligned and driven with the position and speed of the servo motor of each axis synchronized, the characteristics of the controlled object It is known that synchronization errors occur due to differences in motor characteristics, detector characteristics, control gain, input disturbance, and the like.

  In particular, when control input saturation occurs on any of a plurality of axes that perform synchronous control, the follow-up delay increases only for the axis that is subjected to the control input restriction, and the synchronization error is greatly degraded. Therefore, conventionally, measures for preventing performance degradation have been proposed (for example, Patent Document 1).

  That is, in Patent Document 1, the control input is corrected so that the control input of one axis is not restricted by the control input, and the control input is corrected by the same method for the other axis. There is disclosed a technique for preventing deterioration of synchronization accuracy by a method of directly correcting a control input to the control.

JP 2008-72851 A International Publication No. 2005/122385 Pamphlet Japanese Patent Laid-Open No. 9-246359

  However, for example, when synchronous control is performed on axes with different inertias, the control input of each axis needs to be a ratio that is linked to the ratio of inertia in order to maintain synchronization accuracy. However, in the technique described in Patent Document 1, when the control input is subjected to control input restriction, the control input is corrected to a ratio linked to the inertia ratio in order to correct the control input without considering the inertia ratio. Therefore, there has been a problem that it is impossible to synchronize the positions with high accuracy.

  In order to maintain synchronization accuracy, not only when the inertia is different, it is generally necessary to determine the control input for each axis according to the characteristics of the control target and disturbance (friction, gravity, etc.). The characteristics of the target and disturbance (inertia, viscous friction, etc.) are often unknown, and they may change over time. Therefore, the synchronization method in the technique described in Patent Document 1 that directly corrects the control input is not a realistic method.

  Furthermore, since the technique described in Patent Document 1 is a technique for correcting (limiting) the control input for both axes, the tracking delay with respect to the position command is expanded, and the control performance deterioration called a windup phenomenon is caused. And the problem of causing instability of the control system.

  The present invention has been made in view of the above, and is a motor synchronous control device capable of maintaining the synchronization of each axis with high accuracy even when the control input of each axis is limited. The purpose is to obtain.

  In order to solve the above-described problems and achieve the object, a motor synchronous control device according to the present invention is provided for each axis generated by each of two or more motor drive control devices that individually drive and control two or more motors. The position with the slowest response among the two or more position correction amounts, with a position correction amount for correcting the position deviation of the own axis motor, which is the difference between the common position command and the position detection value detected by the own axis motor, being input. A shaping amount synchronization unit that selects a correction amount as a post-synchronization position correction amount is provided, and each of the two or more motor drive control devices has a corrected position deviation obtained by subtracting the post-synchronization position correction amount from the position deviation of its own axis. It is used to calculate the control input to the own axis motor.

  According to the present invention, since the position correction amount calculated independently for each axis is selected so as to match the slowest response axis among all the axes that perform synchronous control, the slow axis is switched during acceleration / deceleration. Even in this case, it is possible to generate a command that can follow all axes. Therefore, even when the control input to the motor is limited, the position correction amount calculated by each motor drive control device can be synchronized, and synchronization of each axis can be maintained with high accuracy. The effect of becoming.

FIG. 1 is a block diagram showing a configuration of a motor synchronous control apparatus according to Embodiment 1 of the present invention. FIG. 2 is a block diagram showing a configuration of a motor synchronous control apparatus according to Embodiment 2 of the present invention. FIG. 3 is a block diagram showing a configuration of a motor synchronous control apparatus according to Embodiment 3 of the present invention. FIG. 4 is a block diagram showing a configuration of a motor synchronous control apparatus according to Embodiment 4 of the present invention. FIG. 5 is a diagram illustrating an example of a time change in position correction. FIG. 6 is a block diagram showing a configuration of a motor synchronous control apparatus according to Embodiment 5 of the present invention. FIG. 7 is a block diagram showing a configuration of a motor synchronous control apparatus according to Embodiment 6 of the present invention. FIG. 8 is a block diagram showing a configuration of a motor synchronous control apparatus according to Embodiment 7 of the present invention.

  Embodiments of a motor synchronous control device according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this embodiment.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of a motor synchronous control apparatus according to Embodiment 1 of the present invention. In addition, in this Embodiment 1 and each embodiment shown below, in order to make an understanding easy, it demonstrates taking the example of the synchronous control between 2 axes | shafts, However, All the contents are applicable also to 3 axes | shafts or more. Is.

  In FIG. 1, a motor synchronous control device 1a according to the first embodiment is based on a position command a output from a position command generating device 2, and is a first axis and second axis servo motor (hereinafter simply referred to as “motor”). ) As a configuration for performing synchronous control of the position and speed of the motors 3a and 3b between the motor drive control devices that individually drive and control 3a and 3b, a shaping amount synchronization unit 4a common to the two axes is provided.

  The motor drive control devices for the first axis and the second axis have the same configuration, and position correction amount calculation units 5a and 5b, command value shaping units 6a and 6b, control input calculation units 7a and 7b, and a control input restriction unit 8a and 8b are provided. Position detectors 9a and 9b for detecting movement (rotation) positions are attached to the motors 3a and 3b, respectively.

  First, the configuration and operation of the motor drive control device for the first axis and the second axis will be described. The control input limiting units 8a and 8b are based on control input limiting values set in accordance with the characteristics of actuators such as motors 3a and 3b and mechanical systems (for example, allowable power of the reducer), respectively. 7b is a filter for limiting the control inputs e1 and e2 from 7b, and outputs a clamped value when limiting.

  That is, when the control inputs e1 and e2 exceed a predetermined control input limit value, the control input limit units 8a and 8b clamp the control inputs e1 and e2 with the predetermined control input limit value, and the predetermined control input The post-limit control inputs f1 and f2 clamped by the limit value are output as drive signals to the motor 3.

  At this time, in the first embodiment, the control input restriction units 8a and 8b respectively control the control input restriction signals g1 and g1 for determining that the control inputs e1 and e2 from the control input calculation units 7a and 7b are restricted. g2 is output. The control input restriction signals g1 and g2 are input to the position correction amount calculation units 5a and 5b.

  The control input limit value may be a fixed limit value set in advance according to the motor characteristics, or may be a value sequentially calculated from feedback information to be controlled. Alternatively, a plurality of control input limit values prepared in advance may be selected according to the acceleration / deceleration state of the motor. Furthermore, when the acceleration of the motors 3a and 3b is positive, a positive control input limit may be used, and when the acceleration is negative, a negative control input limit may be used.

  The control input calculation units 7a and 7b calculate control inputs e1 and e2 to the motors 3a and 3b based on the corrected position deviations d1 and d2 output from the command value shaping units 6a and 6b, respectively. The control input calculators 7a and 7b are configured with feedback compensators (feedback controllers) that have been generally used. Specifically, for example, it is composed of a proportional compensator (P compensator) and a proportional-integral compensator (PI compensator).

  That is, the control input calculation units 7a and 7b calculate the control inputs e1 and e2 to the motors 3a and 3b by performing integral operation, differential operation, and four arithmetic operations on the position deviation (corrected position deviations d1 and d2). . Therefore, the calculation method of the control inputs e1 and e2 is not specified and is arbitrary. Further, the control input calculation units 7a and 7b may be configured by a control system having a minor loop (inner loop) inside, or by a control system in which a speed control system is nested inside the position control system. May be.

  The command value shaping unit 6a includes two subtractors 11a and 12a, and the command value shaping unit 6b includes two subtractors 11b and 12b. The subtractors 11a and 11b subtract the position detection values b1 and b2 detected by the position detectors 9a and 9b from the position command a output from the position command generation device 2, and output position deviations c1 and c2. The subtractors 12a and 12b subtract the post-synchronization position correction amount i output from the shaping amount synchronization unit 4a described later from the position deviations c1 and c2 calculated by the subtractors 11a and 11b, respectively, and obtain corrected position deviations d1 and d2. Output.

  Here, when the shaping amount synchronizer 4a does not exist and the motor drive control devices of the respective axes operate independently, the subtracters 12a and 12b respectively have the positional deviations c1 and c1 calculated by the subtracters 11a and 11b, respectively. The corrected position deviations d1 and d2 are output by subtracting position correction amounts h1 and h2 calculated by position correction amount calculation units 5a and 5b, which will be described later, from c2. In the present embodiment, the command value shaping sections 6a and 6b calculate the position deviations c1 and c2 based on the position command a and the position detection values b1 and b2, as described above, and the calculated position deviations c1 and c2 The corrected position deviations d1 and d2 taking into account the post-synchronization position correction amount i are output.

  In addition, as a structure of command value shaping part 6a, 6b, in FIG. 1, the form which subtracts post-synchronization position correction amount i from position deviation c1, c2 which is the difference of position command a and position detection value b1, b2 ( In this example, the position command is corrected by subtracting the post-synchronization position correction amount i from the position command a, and the position detection values b1 and b2 are subtracted from the corrected position command. A form for calculating the corrected position deviations d1 and d2 (a form for correcting the position command) may be used.

  In the first embodiment, the position correction amount calculation units 5a and 5b calculate correction amounts (position correction amounts h1 and h2) for the position command a or the position deviations c1 and c2 in accordance with the control input saturation countermeasure according to the conventional technique. . Below, two examples of control input saturation countermeasures that are conventional techniques are shown (for example, Patent Documents 2 and 3).

  First, in the control input saturation countermeasure described in Patent Document 2, the position correction amounts h1 and h2 are based on the control input restriction signals g1 and g2 and the position deviation that is the difference between the position command a and the position detection values c1 and c2. Is output. This control input saturation countermeasure is performed as follows.

The positional deviation at a certain time t is DRP (t), the positional deviation at time t = τ is DRP (τ), and the positional deviation at time t = τ + 1 is DRP (τ + 1). At this time, when the control input (current) to the motor at time t = τ is subjected to the control input restriction and the control input restriction signals g1 and g2 are output by the control input restriction units 8a and 8b, In 6b, the position deviations c1 and c2 are corrected so that the position deviation at t = τ + 1 (difference between position command and position detection value, actual position deviation) DRP (τ + 1) satisfies the following expression (1).
DRP ′ (τ + 1) = DRP (τ) (1)

  At this time, the position deviation DRP (τ + 1) at time t = τ + 1 is corrected to DRP ′ (τ + 1), and the position deviation (DRP (τ + 1) −) subtracted to make the position deviations c1 and c2 constant. DRP (τ)) corresponds to the position correction amounts h1 and h2.

  Further, the control input saturation countermeasure described in Patent Document 3 is a control instead of the position deviations c1 and c2 and the control input restriction signals g1 and g2 that are input signals of the position correction amount calculation units 5a and 5b shown in FIG. This corresponds to a form in which the inputs e1 and e2 and the post-restricted control inputs f1 and f2 are input signals. In this control input saturation countermeasure, the difference between the current command amount that is an input / output signal of the control input limiting units 8a and 8b and the actual motor current value is negatively fed back (negative feedback) to the position loop, and the current command amount and the actual The difference from the motor current value corresponds to the position correction amounts h1 and h2.

  As the position correction amount calculation units 5a and 5b used in the present embodiment, the position correction amounts h1 and h2 may be obtained through a filter having a low-pass characteristic with respect to the position correction amounts in the above two conventional techniques. In addition, the position correction amounts h1 and h2 may be set to the position correction amounts in the above two conventional techniques through a filter having an integral characteristic. Furthermore, the correction amounts obtained by multiplying the position correction amounts in the two conventional techniques by a predetermined value may be used as the position correction amounts h1 and h2.

  Now, the shaping amount synchronization unit 4a determines the axis (position correction amount h1, h1) with the slowest response to the position command a from the position correction amounts h1 and h2 calculated by the position correction amount calculation units 5a and 5b of each axis. The position correction amount of the axis with the largest absolute value of h2 is selected, and this is used as the position correction amount (post-synchronization position correction amount i) of each axis, and the subtracters 12a and 12b of the command value shaping units 6a and 6b of each axis Output to.

  Here, the shaping amount synchronization unit 4a selects the position correction amount of the axis with the largest correction amount when the acceleration is positive, and selects the position correction amount of the axis with the smallest correction amount when the acceleration is negative. It may be a form in which it is output as a post-synchronization position correction amount i.

  The shaping amount synchronizer 4a selects the position correction amount of the axis with the largest correction amount when the control inputs e1 and e2 are positive, and selects the axis with the smallest correction amount when the control inputs e1 and e2 are negative. Alternatively, a position correction amount may be selected and output as a post-synchronization position correction amount i.

  Further, the shaping amount synchronization unit 4a may be configured to determine in advance the axis that uses the post-synchronization position correction amount i when the axis with the largest delay among all the axes to be synchronized is known in advance. . And the shaping amount synchronizer 4a can take the form of the following (A) (B) according to the control mode of each axis.

  (A) First, when the motor drive control device for each axis drives each axis at a different number of rotations (position, speed, rotation speed), the motor drive control device for each axis uses a common position command a. Multiply the rotation ratio of each axis, divide the position correction amounts h1 and h2 of each axis by the rotation ratio of each axis at the input stage of the shaping amount synchronization unit 4a, and subtract the command value shaping units 6a and 6b for each axis By multiplying the post-synchronization position correction amount i by the rotation ratio of each axis at the input stage of the units 12a and 12b, it becomes possible to perform the synchronous control taking the synchronization ratio into consideration.

  When the first shaft motor 3a is rotated N1 times and the second shaft motor 3b is rotated N2 times and synchronized, the first rotation ratio is 1, and the second rotation ratio is the second rotation ratio. Is N1 / N2. Alternatively, the first rotation ratio may be N2 / N1, and the second rotation ratio may be 1.

  (B) When the motor drive control device for each axis drives each axis in a different movement direction (rotation direction), the motor drive control device for each axis moves each axis to a common position command a. The sign of the direction (rotation direction) is multiplied, and the position correction amounts h1 and h2 of each axis are divided by the sign of the movement direction (rotation direction) of each axis at the input stage of the shaping amount synchronizer 4a. By multiplying the post-synchronization position correction amount i by the sign of the movement direction (rotation direction) of each axis at the input stage of the subtractors 12a and 12b of the value shaping sections 6a and 6b, the movement direction (rotation direction) of each axis. It is possible to perform synchronous control taking into account The sign of the movement direction (rotation direction) is positive (+) for positive (clockwise) movement (rotation) and negative for negative (counterclockwise) movement (rotation). Value (-).

  As described above, the shaping amount synchronization unit 4a also performs the synchronous control of three or more axes, as described above, the position correction amount of the axis with the slowest response among the position correction amounts of all axes (all axis position correction amount Since the maximum value) is used as a position correction amount (post-synchronization position correction amount) for all axes, the same correction can be performed for all axes. This makes it possible to perform synchronous control with respect to three or more axes with high accuracy.

  Therefore, according to the first embodiment, the position correction amount calculated independently for each axis is selected so as to match the axis with the slowest response among all the axes that perform synchronous control. Even when switching is performed during acceleration / deceleration, it is possible to generate a command that can be followed by all axes. Therefore, even when the control input to the motor is limited, the position correction amount calculated by each motor drive control device can be synchronized, and synchronization of each axis can be maintained with high accuracy. Become.

  In addition, even if the control input is saturated on any of the axes that synchronize position and speed, there is no deterioration in synchronization accuracy (performance degradation such as windup phenomenon or overshoot) or instability. Synchronization accuracy can be maintained.

Embodiment 2. FIG.
FIG. 2 is a block diagram showing a configuration of a motor synchronous control apparatus according to Embodiment 2 of the present invention. In FIG. 2, the same reference numerals are given to components that are the same as or equivalent to the components shown in FIG. 1 (Embodiment 1). Here, the description will be focused on the portion related to the second embodiment.

  As shown in FIG. 2, the motor synchronization control device 1 b according to the second embodiment is different from the configuration shown in FIG. 1 (Embodiment 1) in that each axis instead of the shaping amount synchronization unit 4 a common to the two axes. Are provided with shaping amount synchronizers 14a and 14b.

  The position correction amount h1 calculated by the position correction amount calculation unit 5a for the first axis is input to the shaping amount synchronization unit 14a for the own axis and the shaping amount synchronization unit 14b for the second axis. Similarly, the position correction amount h2 calculated by the second axis position correction amount calculation unit 5b is input to the own axis shaping amount synchronization unit 14b and the first axis shaping amount synchronization unit 14a.

  The shaping amount synchronizers 14a and 14b, respectively, similarly to the shaping amount synchronizer 4a common to the two axes shown in FIG. Position correction amount for each axis is independently selected and output to the subtracters 12a and 12b of the corresponding command value shaping sections 6a and 6b.

  As described above, even in the configuration in which the shaping amount synchronization unit is provided on each axis, the position correction amount of the axis with the slowest response among the position correction amounts of all the axes (the maximum value of the all axis position correction amounts), as in the first embodiment. Is used as a position correction amount (post-synchronization position correction amount) for all axes, so that the same correction can be performed for all axes, and synchronization control can be performed with high accuracy. The same operations and effects as those of Form 1 can be obtained.

  In addition, according to the second embodiment, by providing the shaping amount synchronization unit on each axis, the processing structure on each axis is simplified, which is particularly effective when the number of axes on which synchronization control is performed increases. It becomes a form.

Embodiment 3 FIG.
FIG. 3 is a block diagram showing a configuration of a motor synchronous control apparatus according to Embodiment 3 of the present invention. In FIG. 3, the same reference numerals are given to components that are the same as or equivalent to the components shown in FIG. 1 (Embodiment 1). Here, the description will focus on the part related to the third embodiment.

  In the first and second embodiments, the synchronous control method in the case where the control input saturation countermeasure, which is a conventional technique, is described. In the third embodiment, two or more motor drive control devices with restrictions on the control input each predict the control input saturation in advance and correct the position command or the position deviation in advance, thereby controlling the input. In the case of having a configuration capable of preventing saturation, the same position correction amount (post-synchronization position correction amount) is used for all axes in the same manner as in the first and second embodiments. A synchronous control method that drives the motors with their positions and speeds synchronized will be described. Therefore, the difference between the third embodiment and the first and second embodiments is the configuration of the motor drive control device for each axis.

  That is, as shown in FIG. 3, in the motor synchronous control device 1c according to the third embodiment, the control input in which the sign is changed in the configuration of the motor drive control device for each axis shown in FIG. 1 (first embodiment). Limiting units 16a and 16b and position correction amount calculating units 18a and 18b are provided, and reference position deviation calculating units 17a and 17b are additionally provided.

  Similarly to the control input limiting units 8a and 8b, the control input limiting units 16a and 16b clamp the control inputs e1 and e2 exceeding the limiting value to the limiting value and output the post-limiting control inputs f1 and f2. The control input restriction units 16a and 16b may have a function of outputting the control input restriction signals g1 and g2 shown in FIGS. 1 and 2, but are not used in the third embodiment.

  Next, in FIG. 3, the added reference position deviation calculation units 17a and 17b include the position command a output by the position command generation device 2, the reference control inputs k1 and k2, and the position output by the position detector 9. Although the detection values b1 and b2 are input, as described later, the reference control inputs k1 and k2 are basically necessary, whereas the position command a and the position detection values b1 and b2 are controlled. Depending on the calculation method (internal structure) in the input calculation units 7a and 7b, it may be unnecessary or necessary.

  Here, the reference control inputs k1 and k2 input to the reference position deviation calculation units 17a and 17b are set values for calculating the reference position deviations m1 and m2, and are used by the control input restriction units 16a and 16b. The value may be the same as the input limit value, or may be a value obtained by multiplying the control input limit value by a constant. The control input limit values used as the reference control inputs k1 and k2 may be control input limit values when a plurality of control input limit values prepared in advance are selected according to the acceleration / deceleration state of the motors 3a and 3b. The control input limit value in the case of switching and using the sign of the control input limit value used according to the rotation direction of 3a, 3b may be used.

  The reference position deviation calculation units 17a and 17b are based on at least the predetermined reference control inputs k1 and k2 as described above, and position deviations (corrected position deviations d1 and d2) with respect to the control inputs e1 and e2 calculated by the control input calculation units 7a and 7b. Using the relational expression d2), reference position deviations m1 and m2, which are position deviation amounts for causing the control inputs e1 and e2 to coincide with predetermined reference control inputs k1 and k2, are calculated.

  That is, the control input calculators 7a and 7b calculate the output signals (control inputs e1 and e2) from the input signals (corrected position deviations d1 and d2), whereas the reference position deviation calculators 17a and 17b (Output signals of control input calculation units 7a and 7b) k1 and k2 are used to calculate reference position deviations (input signals of control input calculation units 7a and 7b) m1 and m2. Therefore, when the control input calculation units 7a and 7b have integration characteristics and inner loops (minor loops), the reference position deviation calculation units 17a and 17b consider the influence of the integration characteristics and the influence of the minor loops. The reference position deviations m1 and m2 are calculated from the reference control inputs k1 and k2.

Three examples of reference position deviation calculation are shown below.
(A) For example, when the control input calculation units 7a and 7b are proportional compensators (P compensators), the reference position deviation calculation units 17a and 17b use only the reference control inputs k1 and k2 and reference position deviation m1. , M2 can be calculated. In this case, the input / output relationship of the control input calculators 7a and 7b is expressed by the following equation (2) using the control input U, the proportional gain KP, and the position deviation DRP.
U = KP × DRP (2)

At this time, the reference position deviation DRP ′, which is a position deviation for the control input U to coincide with the reference control input TLMT, is equal to the corrected position deviations d1 and d2 that are inputs of the control input calculation units 7a and 7b, as will be described later. Therefore, it is possible to calculate by dividing the control input U which is the output of the control input calculation units 7a and 7b by the proportional gain KP, and the following equation (3) is obtained.
DRP ′ = TLMT / KP (3)

(B) When the control input calculators 7a and 7b are proportional-integral compensators (PI compensators), the reference position deviation calculators 17a and 17b have reference control inputs k1 and k2, a position command a, and position detection. The reference position deviations m1 and m2 are calculated using the values b1 and b2. In this case, the input / output relationship between the control input calculation units 7a and 7b is expressed by the following equation (time integration value (cumulative value) DRP2 of the control input U, the proportional gain KP, the position deviation DRP, the integral gain KI, and the position deviation DRP: 4).
U = KP × DRP + KI × DRP2 (4)

At this time, the position deviation DRP ′ for matching the control input U with the reference control input TLMT is equal to the corrected position deviations d1 and d2 which are inputs of the control input calculation units 7a and 7b as will be described later. It is possible to calculate by subtracting the integral component in the proportional integral compensator (the value obtained by integrating the position deviation signal and multiplying by the integral gain) from the control input U which is the output of the units 7a and 7b. (5)
DRP ′ = (TLMT−KPI × DRP2) / KP (5)
Here, DRP2 is a value that can be calculated by time-integrating (accumulating) the position deviation, which is the difference between the position command a and the position detection value c.

(C) Further, the control input calculation units 7a and 7b have a position control system and a speed control system, and each compensator (controller) is a position proportional compensator (position P compensator) and a speed proportional integral compensation. When the reference position deviation calculators 17a and 17b are configured with a reference position deviation m1 using the reference control inputs k1 and k2, the position command a and the position detection values b1 and b2. , M2 is calculated. In this case, the input / output relationship of the control input calculation units 7a and 7b is as follows: the time integral value of the control input U, the speed proportional gain KV, the proportional gain KP, the position deviation DRP, the speed detection value VFB, the speed integral gain KI, and the speed deviation VDRP. (Cumulative value) Using VDRP2, the following equation (6) is obtained.
U = KV × (KP × DRP−VFB) + KI × VDRP2 (6)

At this time, the position deviation DRP ′ for causing the control input U to coincide with the reference control input TLMT is equal to the corrected position deviations d1 and d2 which are the inputs of the control input calculators 7a and 7b as will be described later. From the control input U that is the output of the units 7a and 7b, the integral component of the speed controller and the speed detection value can be taken into consideration and the calculation can be performed by the following equation (7).
DRP ′ = ((TLMT−KI × VDRP2) / KV + VFB) / KP (7)

Here, the speed deviation VDRP can be expressed by the following relational expression (8). Further, the speed deviation accumulated value VDRP2 can be calculated by time integration of Expression (8). The speed detection value VFB can be calculated by time differentiation of the position detection values b1 and b2.
VDRP = (KP × DRP−VFB) (8)

  Note that the information (position deviation accumulated value, speed detection value, speed deviation accumulated value, etc.) required by the reference position deviation calculation units 17a and 17b may be generated by calculation inside the reference position deviation calculation units 17a and 17b. Alternatively, a method using the internal signals of the control input calculation units 7a and 7b may be used.

  Next, the position correction amount calculation units 18a and 18b are assumed to include the shaping amount synchronization unit 4a and the motor drive control devices for the respective axes operate independently, and the subtracters of the command value shaping units 6a and 6b. Position correction amounts h1 and h2 given to 12a and 12b are converted into position deviations c1 and c2 from the command value shaping sections 6a and 6b and reference position deviations m1 and m2 from the added reference position deviation calculation sections 17a and 17b. Calculate based on An example of the calculation procedure is shown below.

  The position correction amount calculation units 18a and 18b calculate the control inputs e1 and e2 using the position deviations c1 and c2, and also compare the absolute values of the reference position deviations m1 and m2 and the position deviations c1 and c2. Do. If the absolute values of the reference position deviations m1 and m2 are smaller than the absolute values of the position deviations c1 and c2, the position correction amount calculation units 18a and 18b determine that the calculated control inputs e1 and e2 are control inputs. On the other hand, when the absolute value of the reference position deviations m1 and m2 is larger than the absolute value of the position deviations c1 and c2, it is determined that the calculated control inputs e1 and e2 are not subject to the control input restriction. To do. Then, the position correction amount calculation units 18a and 18b calculate the position correction amounts h1 and h2 for correcting the position deviations c1 and c2 as follows according to the determination result.

  That is, when the absolute values of the reference position deviations m1 and m2 are smaller than the absolute values of the position deviations c1 and c2, the position correction amount calculation units 18a and 18b are subject to the control input restrictions on the calculated control inputs e1 and e2. Therefore, in order to avoid control input saturation due to this, the position deviation is set so that the corrected position deviations d1 and d2 output from the subtracters 12a and 12b of the command value shaping sections 6a and 6b coincide with the reference position deviations m1 and m2. Differences between c1 and c2 and reference position deviations m1 and m2 are calculated as position correction amounts h1 and h2. That is, the position correction amount calculation units 18a and 18b calculate the position correction amounts h1 and h2 so that the position deviations c1 and c2 coincide with the reference position deviations m1 and m2.

  On the other hand, when the absolute values of the reference position deviations m1 and m2 are larger than the absolute values of the position deviations c1 and c2, the position correction amount calculation units 18a and 18b limit the control input to the calculated control inputs e1 and e2. Therefore, the position correction amounts h1 and h2 are set to 0 so that the corrected position deviations d1 and d2 output from the subtracters 12a and 12b of the command value shaping units 6a and 6b coincide with the position deviations c1 and c2 as usual. To do.

  As described in the first and second embodiments, the shaping amount synchronization unit 4a selects the position correction amount of the axis with the slowest response (the axis with the largest correction amount) from the position correction amounts h1 and h2 of each axis. And output to the subtracters 12a and 12b of the corresponding command value shaping sections 6a and 6b.

  According to the third embodiment, the command value shaping (position correction) is performed using the reference control input and the structure of the control input calculation unit. Therefore, even when a position command that restricts the control input is given. In addition, it is possible to automatically generate a command that can follow all the axes to be synchronously controlled while reliably avoiding saturation. For this reason, even when a position command is given such that the control input is restricted, highly accurate synchronous control can be performed.

Embodiment 4 FIG.
FIG. 4 is a block diagram showing a configuration of a motor synchronous control apparatus according to Embodiment 4 of the present invention. In FIG. 4, components that are the same as or equivalent to the components shown in FIG. 3 (Embodiment 3) are assigned the same reference numerals. Here, the description will be focused on the portion related to the fourth embodiment.

  In the fourth embodiment, when two or more motor drive control devices, which are described in the third embodiment, are provided with restrictions on control inputs, each control input calculation unit has a position control system in the control system, A description will be given of a case where the motor is operated with its position and speed synchronized so that the speed of the motor follows the speed command.

When the position command generation device 2 according to the fourth embodiment outputs a speed command to the position control system, the position command increment per unit control cycle using the command speed F and the control cycle TS of the position control system. The value FDT is calculated by the following equation (9), and the accumulated value of the calculated position command increment value FDT is output to the motor drive control device of each axis in the motor synchronous control device 1d according to the fourth embodiment as the position command a. To do.
FDT = F × TS (9)
The position command a may be obtained by performing a moving average process using a predetermined time constant at least once on the position command increment value FDT per unit time.

  As shown in FIG. 4, the motor synchronization control device 1d according to the fourth embodiment is provided with a shaping amount synchronization unit 4b in which the sign is changed in the configuration shown in FIG. 3 (Embodiment 3). Position correction amount updating units 20a and 20b and subtracters 21a and 21b are additionally provided in the shaft motor drive control device.

  The subtractors 21a and 21b subtract the post-synchronization position correction amount i output from the shaping amount synchronization unit 4b from the position deviations c1 and c2 calculated by the subtractors 11a and 11b in the command value shaping units 6a and 6b. The corrected position deviations n1 and n2 are output. The corrected position deviations n1 and n2 are input to the position correction amount calculation units 18a and 18b. That is, in the fourth embodiment, the position correction amount calculation units 18a and 18b receive the position correction amounts h1 and h2 by using the corrected position deviations n1 and n2 obtained by subtracting the post-synchronization position correction amount i from the position deviations c1 and c2. Is calculated.

  The position correction amount update units 20a and 20b calculate the updated position correction amounts p1 and p2 by adding the position correction amounts h1 and h2 and the post-synchronization position correction amount i. Note that the post-update position correction amounts p1 and p2 are calculated only when the acceleration between the motors 3a and 3b is positive, and only when the difference between the position deviations c1 and c2 and the corrected position deviations d1 and d2 is positive. If the accelerations of the motors 3a and 3b are negative, they may be accumulated only when the difference between the position deviations c1 and c2 and the corrected position deviations d1 and d2 is negative.

  The shaping amount synchronization unit 4b with the changed sign performs calculation of the post-synchronization position correction amount i by using the post-update position correction amounts p1 and p2 as an input in the same manner as the shaping amount synchronization unit 4a. FIG. 5 is a diagram illustrating an example of a temporal change in the position correction amount. FIG. 5 shows changes in the position correction amount of the first axis and the second axis, the updated position correction amount, and the post-synchronization position correction amount for each time. As shown in FIG. 5, when the position correction amounts h1 and h2 and the updated position correction amounts p1 and p2 indicate different saturation values for each axis, the post-synchronization position correction amount i calculated by the shaping amount synchronization unit 4b is Saturation values are equal on each axis.

  Here, the post-synchronization position correction amount i is subtracted from the position deviations c1 and c2 to obtain the post-synchronization position deviations p1 and p2. This shows that the movement that cannot be followed by control input is abandoned (ignored) sequentially at the same timing for each axis. This is because, even if the position deviations c1 and c2 are excessive at the present time, the current position deviations c1 and c2 are estimated to be smaller by the amount of accumulated position correction amounts h1 and h2 that have been corrected in the past. (That is, calculating the corrected position deviation). Thus, the position correction amounts h1 and h2 can be calculated based on the relationship between the current position command increment and the position detection value increment.

  Therefore, when a speed command is issued to a control system having a position control system, in the conventional technique, if position correction is performed during acceleration (or deceleration), position deviation will occur even when the speed detection value reaches the command speed. Although c1 and c2 remain in an excessive state, the speed detection value overshoots and causes a windup phenomenon. However, according to the fourth embodiment, the speed detection value is a speed command value. Therefore, it is possible to prevent the position deviations c1 and c2 from becoming excessive at the time of reaching, and to prevent the occurrence of an overshoot or windup phenomenon.

Embodiment 5 FIG.
FIG. 6 is a block diagram showing a configuration of a motor synchronous control apparatus according to Embodiment 5 of the present invention. In FIG. 6, the same or similar components as those shown in FIG. 4 (Embodiment 4) are denoted by the same reference numerals. Here, the description will be focused on the portion related to the fifth embodiment.

  In the fifth embodiment, a case will be described in which the deviation generated between the position command and the position detection value due to the update of the position correction amount described in FIG. 4 (Embodiment 4) is eliminated.

  As shown in FIG. 6, the motor synchronous control device 1e according to the fifth embodiment is additionally provided with an in-rotation position correcting unit 22 in the configuration shown in FIG. 4 (Embodiment 4).

  The position correction unit 22 within one rotation receives the post-synchronization position correction amount i and outputs the position correction amount r after position correction within one rotation. The position correction amount update units 20a and 20b calculate the post-update position correction amounts p1 and p2 with the post-synchronization position correction amount r as an input instead of the post-synchronization position correction amount i shown in FIG. The subtractors 12a and 12b for calculating the corrected position deviations d1 and d2 in the command value shaping sections 6a and 6b perform position correction within one rotation instead of the post-synchronization position correction amount i for the signals to be subtracted from the position deviations c1 and c2. The rear position correction amount r is used.

The position correction unit 22 within one rotation performs the following processes (A) to (B) on the position correction amount i after synchronization to calculate the position correction amount r after position correction within one rotation.
(A) The position correction unit 22 within one rotation normalizes the position correction amount within one rotation (less than one rotation) after the synchronization position correction amount i, abandons the position correction amount after update for multiple rotations (ignored) ), Or by adding / subtracting the position correction amount for multiple rotations.
(B) Next, the position correction unit 22 within one rotation has zero position correction amounts h1 and h2 for all axes (the reference position deviations m1 and m2 are more correct than the corrected position deviations n1 and n2 for all axes). If the normalized position correction amount is other than 0, the normalized position correction amount is set with the difference between the corrected position deviations n1 and n2 and the reference position deviations m1 and m2 as the upper limit. Output as position correction amount r after position correction within one rotation. The position correction amount n after position correction within one rotation may be calculated so as to be a value obtained by performing a moving average process with a predetermined time constant common to each axis.
(C) The one-revolution position correction unit 22 subtracts the one-revolution position correction amount calculated in (1) from the post-synchronization position correction amount i, and subtracts the same within the one-revolution position correction amount r. Output as.

  As a result, the position detection values b1 and b2 of the motors 3a and 3b and the position command a can be corrected so as to coincide with each other, so that the position correction amount described in FIG. 4 (Embodiment 4) is updated. Thus, it is possible to prevent a deviation between the position command and the position detection value.

  As described above, according to the fifth embodiment, it is possible to make the position command and the position detection value coincide with each other within one rotation while the control input does not exceed the limit range and the synchronization system is maintained. As a result, positioning can be performed without any positional deviation. As a result, for example, it is possible to drive the two axes in a synchronized state by synchronizing the phase with the other axes.

Embodiment 6 FIG.
FIG. 7 is a block diagram showing a configuration of a motor synchronous control apparatus according to Embodiment 6 of the present invention. In FIG. 7, the same or similar components as those shown in FIG. 6 (Embodiment 5) are given the same reference numerals. Here, the description will focus on the parts related to the sixth embodiment.

  In the sixth embodiment, as in the fifth embodiment, the difference between the position command and the position detection value due to the update of the position correction amount described in FIG. 4 (fourth embodiment) is eliminated. explain about.

  As shown in FIG. 7, in the motor synchronization control device 1 f according to the sixth embodiment, in the configuration shown in FIG. 6 (fifth embodiment), instead of the shaping amount synchronization unit 4 b and the one-revolution inner position correction unit 22. The shaping amount synchronizers 24a and 24b and the one-rotation position correcting units 25a and 25b are added to the motor drive control device for each axis.

  The subtractors 21a and 21b use the post-correction position deviations n1 and n2 as post-internal rotation position correction amounts r1 and r2 output from the intra-rotation position correction units 25a and 25b, respectively, by subtracting the signals to be subtracted from the positional deviations c1 and c2. It calculates and outputs to position correction amount calculation part 18a, 18b.

  The position correction amount update units 20a and 20b include position correction amounts h1 and h2 output from the position correction amount calculation units 18a and 18b and post-in-rotation position correction post-position correction position amounts r1 output from the in-revolution position correction units 25a and 25b. , R2 as inputs, post-update position correction amounts p1, p2 are calculated.

  The shaping amount synchronizers 24a and 24b calculate the post-synchronization position correction amounts j1 and j2 by using the post-update position correction amounts p1 and p2 calculated by the position correction amount update units 20a and 20b, respectively.

  The position correction units 25a and 25b within one rotation describe the post-synchronization position correction amounts j1 and j2 input from the shaping amount synchronization units 24a and 24b in (A) to (C) described in FIG. 6 (Embodiment 5). Processing is performed to calculate post-position correction position correction amounts r1 and r2 within one rotation.

  The subtractors 12a and 12b for calculating the corrected position deviations d1 and d2 in the command value shaping sections 6a and 6b change the signal to be subtracted from the position deviations c1 and c2 to the post-position correction position correction amount r after one rotation. The post-in-rotation position correction post-correction position correction amounts r1 and r2.

  Thus, even in the configuration in which the shaping amount synchronization unit and the one-revolution position correction unit are provided on each axis, as in the fifth embodiment, the control input does not exceed the limit range and the synchronization system is maintained. Since the position command and the position detection value can be made to coincide with each other within one rotation, positioning can be performed without any positional deviation. For example, the two axes in the synchronized state are synchronized with the phases of the other axes. Can be driven.

  In addition, according to the sixth embodiment, the processing structure in each axis is simplified by providing the shaping amount synchronization unit and the position correcting unit within one rotation on each axis. It becomes a particularly effective form when increases.

Embodiment 7 FIG.
In the seventh embodiment, a correction method when there is a dead time such as a communication delay on the communication path between the synchronized axes in the first to sixth embodiments will be described. Here, for convenience of explanation, correction is performed when there is a dead time such as communication delay in the communication path between the axes to be synchronized using the motor synchronization control device 1b shown in FIG. 2 (Embodiment 2). A method will be described.

  FIG. 8 is a block diagram showing a configuration of a motor synchronous control apparatus according to Embodiment 7 of the present invention. In FIG. 8, components that are the same as or equivalent to the components shown in FIG. 2 (Embodiment 2) are assigned the same reference numerals. Here, the description will be focused on the portion related to the seventh embodiment.

  In the motor synchronous control device 1g according to the seventh embodiment shown in FIG. 8, in the configuration shown in FIG. 2 (Embodiment 2), the communication path for synchronizing the motor drive control devices of the first axis and the second axis. Between the first axis position correction amount calculation unit 5a and the second axis shaping amount synchronization unit 14b, and between the second axis position correction amount calculation unit 5b and the first axis shaping amount synchronization unit 14a. In addition, when there is a dead time, dead time correction units 27a and 27b are provided in the respective communication paths.

  The dead time correction units 27a and 27b receive the position correction amounts h1 and h2 and output the position correction amounts s1 and s2 after the dead time correction. The shaping amount synchronizers 14a and 14b for each axis are synchronized with each other based on the position correction amount for the own axis and the position correction amount after the dead time correction for the other axis, instead of the position correction amounts h1 and h2 for each axis. A position correction amount is calculated. In other words, the first axis shaping amount synchronization unit 14a calculates the first axis post-synchronization position correction amount j1 based on the first axis position correction amount h1 and the second axis dead time corrected position correction amount s2. . The second axis shaping amount synchronization unit 14b calculates the second axis post-synchronization position correction amount j2 based on the first axis dead time corrected position correction amount s1 and the second axis position correction amount h2.

The dead time correction units 27a and 27b perform the same operation. That is, as shown in the following equation (10), the dead time correction units 27a and 27b add the product of the differential value (difference value) VC of the position correction amount PC and the correction time TC to the position correction amount PC. The position detection value PC ′ after dead time correction is output.
PC ′ = PC + VC × TC (10)

When the position correction amount PC is a signal including the dead time TD, the dead time can be corrected by calculating Expression (10) using the correction time TC as the dead time TD. Further, when the position correction amount PC is a discrete value, VC is a difference value of the position correction amount PC and can be calculated by the following equation (11).
VC (t) = PC (t) −PC (t−1) (11)
In equation (11), t is a time obtained by multiplying the interpolation period of the control system by a constant.

  Thus, according to the seventh embodiment, even when the position correction amount is synchronized in a state where the position correction amount is delayed by the dead time, the influence of the dead time can be reduced, and the control input restriction is achieved. In contrast, accurate command value shaping becomes possible.

  In addition, the correction position command can be predicted by setting the correction time TC as the estimated time TE. Note that the dead time correction method described in the seventh embodiment is not limited to a path that synchronizes a path in which dead time exists, but an internal signal of a motor drive control device, a position command generation device, and a motor. The present invention can also be applied to a case where a dead time is included with the drive control device.

  As described above, the motor synchronization control device according to the present invention is a motor synchronization control device that can maintain the synchronization of each axis with high accuracy even when the control input of each axis is limited. Useful.

1a, 1b, 1c, 1d, 1e, 1f, 1g Motor synchronous control device 2 Position command generation device 3a, 3b Motor (servo motor)
4a, 4b, 14a, 14b, 24a, 24b Shaping amount synchronization unit 5a, 5b, 18a, 18b Position correction amount calculation unit 6a, 6b Command value shaping unit 7a, 7b Control input calculation unit 8a, 8b, 16a, 16b Control input Limiting units 9a, 9b Position detectors 11a, 11b, 12a, 12b, 21a, 21b Subtractors 17a, 17b Reference position deviation calculating units 20a, 20b Position correction amount updating units 22, 25a, 25b Position correction units within one rotation 27a, 27b Dead time correction unit

Claims (8)

Each of the two or more motor drive control devices that individually drive two or more motors is a difference between a position command common to each axis and a position detection value detected by the own motor. A position correction amount for correcting a position deviation is input, and a shaping amount synchronization unit that selects a position correction amount with the slowest response among the two or more position correction amounts as a post-synchronization position correction amount,
Each of the two or more motor drive control devices calculates a control input to the own axis motor using a corrected position deviation obtained by subtracting the post-synchronization position correction amount from the position deviation of the own axis.
The motor synchronous control apparatus characterized by the above-mentioned. The shaping amount synchronization unit is input as a value obtained by dividing the position correction amount of each axis by the rotation ratio of each axis,
Each of the two or more motor drive control devices automatically multiplies the position command by the rotation ratio of the own shaft, the correction position deviation, and the value obtained by multiplying the post-synchronization position correction amount by the rotation ratio of the own shaft. Generated by subtracting from the axis position deviation,
The motor synchronous control device according to claim 1. The shaping amount synchronization unit is input as a value obtained by dividing the position correction amount of each axis by the sign of the movement direction (rotation direction) of each axis,
Each of the two or more motor drive control devices multiplies the position command by a sign of its own axis movement direction (rotation direction), and calculates the corrected position deviation to the post-synchronization position correction amount as its own axis movement direction ( 2. The motor synchronous control device according to claim 1, wherein a value obtained by multiplying a sign of the rotation direction is generated by subtracting from a position deviation of the own axis. The shaping amount synchronizer inputs, as a position correction amount for each axis, a position correction amount after dead time correction obtained by adding the position correction amount to a value obtained by multiplying the difference between the position correction amounts by a correction time from each axis. To be
The motor synchronous control device according to any one of claims 1 to 3, wherein Each of the two or more motor drive control devices includes:
A position correction amount calculation unit that calculates the position correction amount based on the position deviation and a control input restriction signal that determines that the control input to the own-axis motor is restricted;
The motor synchronous control device according to any one of claims 1 to 4, further comprising: Each of the two or more motor drive control devices includes:
A reference position deviation for matching the control input to the reference control input based on the relationship between the input and the input of the control input calculation unit that calculates at least the reference control input as an input and calculates the control input to the own-axis motor. A reference position deviation calculator for calculating,
The absolute value of the positional deviation is compared with the absolute value of the reference positional deviation, and when the absolute value of the reference positional deviation is smaller than the absolute value of the positional deviation, the positional deviation is referred to by the positional deviation. A position correction amount calculation unit that calculates and outputs the position correction value so that the absolute value of the reference position deviation is larger than the absolute value of the position deviation;
The motor synchronous control device according to any one of claims 1 to 4, further comprising: Each of the two or more motor drive control devices includes:
A position correction amount updating unit that updates the position correction amount by adding the post-synchronization position correction amount to the position correction amount;
The position correction amount calculation unit replaces the input with the position deviation, and calculates a corrected position deviation obtained by subtracting the post-synchronization position correction amount from the position deviation.
The shaping amount synchronization unit replaces the input with the position correction amount, and uses the updated position correction amount generated by the position correction amount update unit.
The motor synchronous control device according to claim 5 or 6, characterized by the above. On the output side of the shaping amount synchronization unit, the position correction amount for one rotation is added to or subtracted from the post-synchronization position correction amount to obtain a position correction amount of less than one rotation, and the position correction amount of less than one rotation is calculated as the synchronization amount. A position correction unit within one rotation that outputs a position correction amount after position correction within one rotation by subtracting from the position correction amount after rear rotation is provided,
Each of the two or more motor drive control devices includes:
Instead of the post-synchronization position correction amount, the input of the position correction amount update unit is the post-position correction position correction amount within one rotation, and the input of the position correction amount calculation unit is the post-synchronization position from the position deviation Instead of a corrected position deviation obtained by subtracting a correction amount, a corrected position deviation is obtained by subtracting a position correction amount after position correction within one rotation from the position deviation. Instead of a value obtained by subtracting the post-synchronization position correction amount, a value obtained by subtracting the position correction amount after position correction within one rotation from the position deviation of the own axis,
The motor synchronous control apparatus according to claim 7.

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