JP2010178509A - Motor drive control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a motor drive control device which can prevent the deterioration of control performance, without fail, and the unstable operation of a control system caused by the saturation of a control input. <P>SOLUTION: A reference position difference calculation section 4a calculates a reference position difference d for making the control input h coincide with a reference control input b, on the basis of a relationship between an output and an input of a control input calculation section 7. When the absolute value of the reference position difference d is smaller than the absolute value of a position difference e, a position correction amount calculating part 5a calculates a position correction amount f so that the position difference e coincides with the reference position difference d and outputs it; and when the absolute value of the reference position difference d is larger than the absolute value of the position difference e, the position correction amount calculation section sets the position correction amount f to zero and outputs it. A command value generating section 6a sets a corrected position difference g which is generated, by subtracting the position correction amount f from the position difference e, as an input signal of the control input calculating section 7. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a motor drive control device that drives and controls a servomotor used to drive a machine tool.

  In general, a motor drive control device that controls the drive of a servo motor, etc. has a limit on the control input that can be input for the purpose of protecting the motor, so if a movement command exceeding the control input limit is given, the control input Winding-up phenomenon that causes overshoot in the output response when saturation occurs may cause control performance degradation and control system instability. For this reason, conventionally, as a measure for preventing this performance deterioration, for example, it is necessary to take a saturation measure against the control input restriction as disclosed in Patent Document 1.

  That is, in Patent Document 1, by providing a certain restriction on the speed command for a controlled object having a restriction on the control input to the motor, the integral output is prevented from becoming excessive, and the control input is prevented from being saturated. Techniques to do this are disclosed.

Japanese Patent No. 3994208

  However, in the technique described in Patent Document 1, since measures are taken to prevent the control input from becoming excessive by limiting the speed command with respect to the position command, the motor speed becomes less than the limit speed. Saturation countermeasures in the state could not be taken.

  In addition, since the relationship between the control input limit and the speed limit is not clear, when setting the speed limit so as to cover all possible control input saturations, it is necessary to set a small speed limit and the travel time. It was the cause that became long.

  The present invention has been made in view of the above, and an object of the present invention is to provide a motor drive control device that can reliably prevent control performance deterioration and control system instability due to saturation of a control input.

  In order to solve the above-described problems and achieve the object, the present invention provides at least a reference control input as an input in a motor drive control device in which a control input to a motor that performs drive control based on a position command is limited. A reference position deviation calculating unit for calculating a reference position deviation for the control input to match the reference control input based on a relationship between an output and an input of a control input calculating unit that calculates a control input; and the position command; When the absolute value of the position deviation, which is a difference from the detected position detection value of the motor, is compared with the absolute value of the reference position deviation, and the absolute value of the reference position deviation is smaller than the absolute value of the position deviation Calculates and outputs a position correction amount for correcting the position deviation so that the position deviation matches the reference position deviation, and the absolute value of the reference position deviation is larger than the absolute value of the position deviation. A position correction amount calculation unit that outputs a position correction amount that corrects the position deviation as zero, and a corrected position correction amount that is generated by subtracting the position correction amount from the position deviation. And a command value shaping unit as an input signal.

  According to the present invention, since it is possible to execute motor drive control in consideration of control input restriction, it is possible to reliably prevent control performance deterioration and control system instability due to saturation of the control input.

FIG. 1 is a block diagram showing a configuration of a motor drive control device according to Embodiment 1 of the present invention. FIG. 2 is a block diagram showing the configuration of the motor drive control device according to Embodiment 2 of the present invention. FIG. 3 is a block diagram showing the configuration of the motor drive control apparatus according to Embodiment 3 of the present invention. FIG. 4 is a block diagram showing a configuration of a motor drive control apparatus according to Embodiment 4 of the present invention. FIG. 5 is a block diagram showing a configuration of a motor drive control apparatus according to Embodiment 5 of the present invention. FIG. 6 is a block diagram showing a configuration of a motor drive control device according to Embodiment 6 of the present invention. FIG. 7 is a block diagram showing a configuration of a motor drive control device according to Embodiment 7 of the present invention. FIG. 8 is a block diagram showing the configuration of the motor drive control apparatus according to Embodiment 8 of the present invention. FIG. 9 is a block diagram showing a configuration of a motor drive control device according to Embodiment 9 of the present invention.

  Embodiments of a motor drive 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 drive control device according to Embodiment 1 of the present invention. Referring to FIG. 1, a motor drive control device 1a according to the first embodiment moves a servo motor (hereinafter simply referred to as “motor”) 3 within a control input restriction range based on a position command a output from a position command generation device 2. The drive position control unit includes a reference position deviation calculation unit 4, a position correction amount calculation unit 5a, a command value shaping unit 6a, a control input calculation unit 7, and a control input restriction unit 8. A position detector 9 for detecting the drive position is attached to the motor 3.

  Hereinafter, the configuration and operation of each of these elements will be described. First, the control input restriction unit 8 is a control input from the control input calculation unit 7 based on a control input restriction value set according to the characteristics of an actuator such as the motor 3 or a mechanical system (for example, the allowable force of the speed reducer). This is a filter for limiting h. When the control input h exceeds a predetermined control input limit value, the control input h is clamped at the predetermined control input limit value and clamped at the predetermined control input limit value. The post-limit control input i is output as a drive signal to the motor 3.

  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 motor 3 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 unit 7 calculates a control input h to the motor 3 based on the corrected position deviation g output from the command value shaping unit 6a. The control input calculation unit 7 is composed of a feedback compensator (feedback controller) that has 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 unit 7 calculates the control input h to the motor 3 by performing integral operation, differential operation, and four arithmetic operations on the position deviation (corrected position deviation g). Therefore, the calculation method of the control input h is not specified and is arbitrary. The control input calculation unit 7 may be configured by a control system having a minor loop (inner loop) inside, or may be configured by a control system in which a speed control system is nested inside the position control system. Good.

  In FIG. 1, the position command a output from the position command generator 2, the reference control input b, and the position detection value c output from the position detector 9 are input to the reference position deviation calculation unit 4. However, as will be described later, the reference control input b is basically necessary, whereas the position command a and the position detection value c are calculated by the calculation method (internal structure) in the control input calculation unit 7. There are cases where it is unnecessary and cases where it is necessary.

  Here, the reference control input b input to the reference position deviation calculation unit 4 is a set value for calculating the reference position deviation d, and is the same value as the control input limit value used by the control input limit unit 8 or It is a value obtained by multiplying the control input limit value by a constant. The control input limit value used as the reference control input b may be a control input limit value when a plurality of control input limit values prepared in advance are selected according to the acceleration / deceleration state of the motor 3, and the rotation direction of the motor 3 The control input limit value when the sign of the control input limit value to be used is switched according to the above.

  The reference position deviation calculation unit 4 uses a relational expression of the position deviation (corrected position deviation g) with respect to the control input h calculated by the control input calculation unit 7 based on at least a predetermined reference control input b, so that the control input h is predetermined. The reference position deviation d, which is a position deviation amount for matching the reference control input b, is calculated.

  That is, the control input calculation unit 7 calculates the control input h from the corrected position deviation g, whereas the reference position deviation calculation unit 4 calculates the reference position deviation (control input) from the reference control input (output signal of the control input calculation unit). The input signal of the calculation unit) is calculated. Therefore, when the control input calculation unit 7 has an integral characteristic or an inner loop (minor loop), the reference position deviation calculation unit 4 considers the influence of the integral characteristic and the influence of the minor loop, and then the reference control input b Thus, the reference position deviation d is calculated.

Three examples of reference position deviation calculation are shown below.
(1) For example, when the control input calculation unit 7 is a proportional compensator (P compensator), the reference position deviation calculation unit 4 may calculate the reference position deviation d using only the reference control input b. it can. The input / output relationship of the control input calculation unit 7 in this case is expressed by the following expression (1) using the control input U, the proportional gain KP, and the position deviation DRP.
U = KP × DRP (1)

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 deviation g which is an input of the control input calculation unit 7. It is possible to calculate by dividing the control input U, which is an output, by the proportional gain KP, and the following equation (2) is obtained.
DRP ′ = TLMT / KP (2)

(2) When the control input calculator 7 is a proportional integral compensator (PI compensator), the reference position deviation calculator 4 uses the reference control input b, the position command a, and the position detection value c. The reference position deviation d is calculated. The input / output relationship of the control input calculation unit 7 in this case is expressed by the following equation (3) using the control input U, the proportional gain KP, the position deviation DRP, the integral gain KI, and the time integral value (cumulative value) DRP2 of the position deviation DRP. )
U = KP × DRP + KI × DRP2 (3)

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 deviation g which is an input of the control input calculation section 7 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 expressed by the following equation (4).
DRP ′ = (TLMT−KPI × DRP2) / KP (4)
Here, DRP2 is a value that can be calculated by time-integrating (accumulating) the difference (position deviation) between the position command a and the position detection value c.

(3) The control input calculation unit 7 includes a position control system and a speed control system, and each compensator (controller) includes a position proportional compensator (position P compensator) and a speed proportional integral compensator ( In the case of a configuration including a speed PI compensator, the reference position deviation calculation unit 4 calculates the reference position deviation d using the reference control input b, the position command a, and the position detection value c. In this case, the input / output relationship of the control input calculation unit 7 is as follows: the time integral value (accumulation) 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. Value) Using VDRP2, the following equation (5) is obtained.
U = KV × (KP × DRP−VFB) + KI × VDRP2 (5)

At this time, since the position deviation DRP ′ for the control input U to coincide with the reference control input TLMT is equal to the corrected position deviation g which is an input of the control input calculation section 7 as will be described later, the output of the control input calculation section 7 From the control input U, 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 (6).
DRP ′ = ((TLMT−KI × VDRP2) / KV + VFB) / KP (6)

Here, the speed deviation VDRP can be expressed by the following relational expression (7). Further, the speed deviation accumulated value VDRP2 can be calculated by time integration of Expression (7). The speed detection value VFB can be calculated by time differentiation of the position detection value c.
VDRP = (KP × DRP−VFB) (7)

  Information required by the reference position deviation calculation unit 4 (position deviation accumulated value, speed detection value, speed deviation accumulated value, etc.) may be generated by a calculation in the reference position deviation calculation unit 4 or by control input calculation. A method using the internal signal of the unit 7 may be used.

  Next, the command value shaping unit 6a includes two subtractors 11a and 11b. The subtractor 11a subtracts the position detection value c detected by the position detector 9 from the position command a output from the position command generation device 2 and outputs a position deviation e. The subtractor 11b subtracts the position correction amount f calculated by the position correction amount calculation unit 5a from the position deviation e calculated by the subtractor 11a, and outputs a corrected position deviation g. As described above, the command value shaping unit 6a calculates the position deviation e based on the position command a and the position detection value c, and outputs a corrected position deviation g obtained by adding the position correction amount f to the calculated position deviation e. To do.

  Next, the reference position deviation d is input from the reference position deviation calculation unit 4 and the position deviation e is input from the command value shaping unit 6a to the position correction amount calculation unit 5a. The position correction amount calculation unit 5a calculates the control input h using the position deviation e, and compares the absolute values of the reference position deviation d and the position deviation e with each other. When the absolute value of the reference position deviation d is smaller than the absolute value of the position deviation e as a result of the comparison, the position correction amount calculation unit 5a determines that the calculated control input h is subject to control input restriction, and is referred to If the absolute value of the position deviation d is greater than the absolute value of the position deviation e, it is determined that the calculated control input h is not subject to control input restrictions.

  Then, the position correction amount calculation unit 5a calculates the position correction amount f for correcting the position deviation e as follows according to the determination result. That is, when the absolute value of the reference position deviation d is smaller than the absolute value of the position deviation e, the position correction amount calculation unit 5a calculates the position correction amount f so that the position deviation e matches the reference position deviation d. To do. That is, a value obtained by subtracting the reference position deviation d from the position deviation e is set as the position correction amount f. As a result, when the calculated control input h is subjected to control input restriction, the corrected position deviation g matched with the reference position deviation d is output from the subtractor 11b of the command value shaping unit 6a, so that the control input in advance Saturation can be avoided.

  On the other hand, when the absolute value of the reference position deviation d is larger than the absolute value of the position deviation e, the position correction amount calculation unit 5a sets the position correction amount f to 0. As a result, when the calculated control input h is not subject to the control input restriction, the corrected position deviation g matched with the actual position deviation e can be output as usual from the subtractor 11b of the command value shaping unit 6a. it can.

  When it is predicted in advance that the control input h is restricted by the cooperation of the reference position deviation calculation unit 4a, the position correction amount calculation unit 5a, and the command value shaping unit 6a that operate as described above, the reference control input b Control input h using information of control input calculation unit 7 (relationship between control input h and position deviation (corrected position deviation g)), position command a, and position detection value c, which are known information. Is matched with the reference control input b to correct the actual position deviation (position droop, actual position droop). In particular, when the reference control input b and the control input limit are set to the same value, the position deviation e is corrected so that the control input h does not exceed the control input limit value. As a result, control input saturation can be prevented in advance, and drive control of the motor 3 can be performed without destabilization.

  That is, according to the first embodiment, in the motor drive control device in which the control input to the motor is limited, the control input is predicted in advance and the control input limitation is taken into consideration. Since motor drive control can be executed, the occurrence of a windup phenomenon can be prevented in advance, and performance deterioration and instability due to control input saturation can be reliably prevented.

Embodiment 2. FIG.
FIG. 2 is a block diagram showing the configuration of the motor drive control device 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 drive control device 1 b according to the second embodiment includes a position correction amount calculation unit 5 b and a command value shaping unit 6 b with different signs in the configuration shown in FIG. 1 (first embodiment). Is provided.

  The command value shaping unit 6b includes two subtractors 12a and 12b, but the subtraction contents are different from the command value shaping unit 6a. The subtractor 12a subtracts the position correction amount f output from the position correction amount calculation unit 5b from the position command a output from the position command generation device 2, and outputs a corrected position command j. The subtractor 12b subtracts the position detection value c output from the position detector 9 from the corrected position command j output from the subtractor 12a, and outputs a corrected position deviation g. In this manner, the command value shaping unit 6b corrects the position command by subtracting the position correction amount f from the position command a, and subtracts the position detection value c from the corrected corrected position command j, thereby correcting the corrected position deviation g. Is output.

  A position command a output from the position command generation device 2, a reference position deviation d output from the reference position deviation calculation unit 4, and a position detection value c output from the position detector 9 are input to the position correction amount calculation unit 5b. The That is, unlike the position correction amount calculation unit 5a, the position correction amount calculation unit 5b calculates the position correction amount f by calculating the position deviation internally.

  That is, the position correction amount calculation unit 5b obtains a position deviation by taking the difference between the position command a and the position detection value c, calculates the control input h using the calculated position deviation, and also calculates the calculated value. The absolute values of the position deviation and the reference position deviation d are compared in magnitude. If the absolute value of the reference position deviation d is smaller than the calculated absolute value of the position deviation as a result of the comparison, it is determined that the calculated control input h is subject to control input restriction, and the absolute value of the reference position deviation d is calculated. If it is larger than the absolute value of the position deviation, it is determined that the calculated control input h is not subject to the control input restriction.

  When the absolute value of the reference position deviation d is smaller than the calculated absolute value of the position deviation, the position correction amount calculation unit 5a matches the reference position deviation d with the value obtained by subtracting the position detection value c from the position deviation. Thus, the position correction amount f is calculated. Accordingly, when the calculated control input h is subject to control input restriction, the command value shaping unit 6b subtracts the position detection value c from the corrected position command j obtained by subtracting the position correction amount f from the position command a. A corrected position deviation g that matches the reference position deviation d is output.

  On the other hand, when the absolute value of the reference position deviation d is larger than the absolute value of the calculated position deviation, the position correction amount calculation unit 5 sets the position correction amount f to a value of 0. As a result, when the calculated control input h is not subject to the control input restriction, the command value shaping unit 6b outputs the position command a as the corrected position command j in the command value shaping unit 6b. Is output as a corrected position deviation g.

  Therefore, since the operation similar to that in the first embodiment is performed in the second embodiment, the control input is limited in advance in the motor drive control device in which the control input to the motor is similarly limited. Predictive and motor drive control that takes control input restrictions into account can be executed, preventing the occurrence of windup phenomena and ensuring performance degradation and instability due to control input saturation. Can be prevented.

  In addition, in the second embodiment, the command value shaping unit can be separated into a part that calculates the corrected position command from the position command and a part that calculates the difference between the corrected position command and the position detection value and performs feedback processing. Since it is a structure, it becomes possible to perform command value shaping in consideration of the control input of the motor by a position command generation device such as a numerical controller (NC) or a motion controller.

Embodiment 3 FIG.
FIG. 3 is a block diagram showing the configuration of the motor drive 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.

  As shown in FIG. 3, the motor drive control device 1c according to the third embodiment is modified in place of the position correction amount calculation unit 5a and the command value shaping unit 6a in the configuration shown in FIG. 1 (Embodiment 1). A position selection unit 15a is provided, and a subtracter 16 is additionally provided.

  The subtracter 16 subtracts the position detection value c detected by the position detector 9 from the position command a output from the position command generation device 2 and outputs a position deviation e.

  The correction position selection unit 15a receives the position deviation e calculated by the subtracter 16 and the reference position deviation d calculated by the reference position deviation calculation unit 4a, and outputs a correction position deviation g. The corrected position deviation selection unit 15a calculates the control input h using the position deviation e, and outputs the position deviation e as the corrected position deviation g when it is determined that the calculated control input is not subject to the control input restriction. On the other hand, if the corrected position selection unit 15a determines that the calculated control input is subject to control input restriction, the corrected position selection unit 15a performs control by switching the reference position deviation d and the position deviation e to the smaller absolute value. Avoid input restrictions.

  Therefore, since the operation similar to that of the first embodiment is performed also in the third embodiment, the control input is limited in advance in the motor drive control device in which the control input to the motor is similarly limited. Predictive and motor drive control that takes control input restrictions into account can be executed, preventing the occurrence of windup phenomena and ensuring performance degradation and instability due to control input saturation. Can be prevented.

Embodiment 4 FIG.
FIG. 4 is a block diagram showing a configuration of a motor drive 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 first to third embodiments, the input / output relationship of the control input calculation unit 7 is used to calculate a position deviation (corrected position deviation g) such that the control input h does not become the control input limit, thereby preventing saturation of the control input h. In the fourth embodiment and the fifth embodiment, which will be described later, the case where the control input calculation unit 7 has a position control system in the control system and operates the motor speed in accordance with the speed command will be described. To do.

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 (8), and the accumulated value of the calculated position command increment value FDT is output as the position command a to the motor drive control device 1d according to the fourth embodiment.
FDT = F × TS (8)
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 drive control device 1d according to the fourth embodiment is provided with a correction position selection unit 15b having a different sign in the configuration shown in FIG. 3 (Embodiment 3). A position correction amount updating unit 17a and a subtracter 18 are additionally provided.

  The subtracter 18 subtracts the updated position correction amount m calculated by the position correction amount update unit 17a from the position deviation e calculated by the subtracter 16, and outputs a corrected position deviation k. The corrected position deviation k is input to the corrected position selection unit 15b and the position correction amount update unit 17a.

  The correction position selection unit 15b calculates the correction position deviation g using the reference position deviation d and the corrected position deviation k in the same manner as the correction position selection unit 15a shown in FIG.

  The position correction amount updating unit 17a adds the difference between the corrected position deviation k and the corrected position deviation g to the previous value of the updated position correction amount m, and outputs the updated position correction amount m. The post-update position correction amount m can be calculated by accumulating only when the difference between the post-correction position deviation k and the corrected position deviation g is positive when the acceleration of the motor 3 is positive. When the acceleration of 3 is negative, it may be accumulated only when the difference between the corrected position deviation k and the corrected position deviation g is negative.

  Here, subtracting the updated position correction amount m from the position deviation e to obtain the corrected position deviation k sequentially abandons (ignores) the movement that cannot be followed even by the maximum control input of the motor 3. It is shown that. This is because even if the position deviation is excessive at the present time, the position deviation at the present time is estimated to be small by the amount of accumulated position correction amount that has been corrected in the past (that is, the position after the correction) Equivalent to calculating the deviation). As a result, the position correction amount can be calculated based on the relationship between the current position command increment and the position detection value increment.

Therefore, when performing a speed command to a control system having a position control system,
If position correction is performed during acceleration (or deceleration), the position deviation will remain excessive even when the speed detection value reaches the command speed, causing the speed detection value to overshoot, resulting in a windup phenomenon. However, according to the fourth embodiment, it is possible to prevent the position deviation from becoming excessive when the speed detection value reaches the speed command value. Occurrence can be prevented.

Embodiment 5 FIG.
FIG. 5 is a block diagram showing a configuration of a motor drive control apparatus according to Embodiment 5 of the present invention. In FIG. 5, 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 fifth embodiment.

  Similarly to the position command generation device 2 in the fourth embodiment, the position command generation device 2 in the fifth embodiment also outputs the command speed F and the control cycle of the position control system when outputting a speed command to the position control system. Using TS, the position command increment value FDT per unit control cycle is calculated by the above equation (8), and the accumulated value of the calculated position command increment value FDT is used as the position command a to perform motor drive control according to the fifth embodiment. Output to the device 1e.

  As shown in FIG. 5, the motor drive control device 1 e according to the fifth embodiment is provided with a position correction amount calculation unit 5 c in which the sign is changed in the configuration shown in FIG. 1 (first embodiment). In addition, a position correction amount updating unit 17b and a subtracter 18 are additionally provided.

  The subtractor 18 subtracts the updated position correction amount m calculated by the position correction amount update unit 17b from the position deviation e calculated by the subtractor 11 of the command value shaping unit 6a to obtain a corrected position deviation k. Output. The corrected position deviation k is input to the position correction amount calculation unit 5c.

  The position correction amount calculation unit 5c calculates the position correction amount f by using the reference position deviation d and the corrected position deviation k in the same manner as the position correction amount calculation unit 5a shown in FIG.

  The position correction amount update unit 17b calculates the updated position correction amount m by adding the position correction amount f to the previous value of the updated position correction amount m.

  In the command value shaping unit 6a, the difference between the position deviation e and the updated position correction amount m is output as the corrected position deviation g from the subtractor 11b.

  Even in this configuration, similarly to the fourth embodiment, the corrected position deviation k is obtained by subtracting the updated position correction amount m from the position deviation e, so that the movement amount that cannot be followed even by the maximum control input of the motor 3 is obtained. Are abandoned (ignored) sequentially. Therefore, since the position correction amount can be calculated based on the relationship between the current position command increment and the position detection value increment, when the speed command is issued to the control system having the position control system, the speed detection value is the speed command. When the value reaches the value, it is possible to prevent the position deviation from becoming excessive, and it is possible to prevent the occurrence of an overshoot or a windup phenomenon.

Embodiment 6 FIG.
FIG. 6 is a block diagram showing a configuration of a motor drive control device according to Embodiment 6 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 focus on the parts related to the sixth embodiment.

  In the sixth embodiment, a case will be described in which the deviation generated between the position command and the position detection value is eliminated by updating the position correction amount described in FIG. 4 (Embodiment 4).

  As shown in FIG. 6, the motor drive control device 1 f according to the sixth embodiment includes a position correction amount update unit 17 c and a subtractor 20 with different signs in the configuration shown in FIG. 4 (fourth embodiment). A one-rotation position correcting unit 19 is additionally provided.

  The subtracter 20 subtracts the position correction amount n after one-rotation position correction calculated by the position correction unit 19 within one rotation from the position deviation e calculated by the subtracter 16 and outputs a position deviation k after correction. To do. The corrected position deviation k is input to the corrected position selection unit 15b and the position correction amount update unit 17c.

  The position correction amount updating unit 17c adds the previous value of the position correction amount n after one rotation output from the position correction unit 19 within one rotation to the value obtained by subtracting the correction position deviation g from the position deviation k after correction. The post-update position correction amount m is calculated. The post-update position correction amount m is input to the position correction unit 19 within one rotation.

The position correction unit 19 within one rotation calculates the position correction amount n after position correction within one rotation by performing the following processes (1) to (3) for the position correction amount m after update.
(1) The position correction unit 19 within one rotation normalizes the position correction amount within one rotation (less than one rotation) after the updated position correction amount m, and abandons the position correction amount after multiple rotations (ignored) ), Or by adding / subtracting the position correction amount for multiple rotations.
(2) Next, the position correction unit 19 within one rotation is the corrected position deviation k when the updated position correction amount m matches the previous value and the normalized position correction amount is other than 0. The normalized position correction amount is output as the post-position correction position correction amount n with the difference between the reference position deviation d as the upper limit. 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.
(3) Further, the position correction unit 19 within one rotation subtracts the position correction amount within one rotation calculated in (1) from the post-update position correction amount m, and subtracts the position correction amount after one position correction after n within the one rotation. Output as.

  As a result, the position detection value c of the motor 3 and the position command a can be corrected so as to coincide with each other, so that the position command and position can be corrected by updating the position correction amount described in FIG. It is possible to prevent a deviation from occurring between the detected value and the detected value.

  As described above, according to the sixth embodiment, the position within each rotation of the position command and the position detection value can be matched without the control input exceeding the limit range. It becomes possible to do. As an example, it is possible to perform an indexing operation (orientation operation) that is required when changing tools.

Embodiment 7 FIG.
FIG. 7 is a block diagram showing a configuration of a motor drive control device according to Embodiment 7 of the present invention. In FIG. 7, the same reference numerals are given to components that are the same as or equivalent to those shown in FIG. 5 (Embodiment 5). Here, the description will be focused on the portion related to the seventh embodiment.

  In the seventh embodiment, a case will be described in which the deviation generated between the position command and the position detection value is eliminated by updating the position correction amount shown in FIG. 5 (fifth embodiment).

  As shown in FIG. 7, the motor drive control device 1g according to the seventh embodiment includes a position correction amount update unit 17d and a subtractor 20 with different signs in the configuration shown in FIG. 5 (fifth embodiment). A one-rotation position correcting unit 19 is additionally provided.

  The subtracter 20 corrects by subtracting the position correction amount n after one-rotation position correction calculated by the one-turn inner position correction unit 19 from the position deviation e calculated by the subtractor 11a of the command value shaping unit 6a. The rear position deviation k is output. The corrected position deviation k is input to the position correction amount calculation unit 5c and the position correction amount update unit 17d.

  The position correction amount update unit 17d calculates the post-update position correction amount m by adding the position correction amount f to the previous value of the position correction amount n after one rotation position correction output from the position correction unit 19 within one rotation. The post-update position correction amount m is input to the position correction unit 19 within one rotation.

  The position correction unit 19 within one rotation performs the processes (1) to (3) shown in FIG. 6 (Embodiment 6) for the post-update position correction amount m to obtain the position correction amount n after one rotation correction. calculate.

  As a result, the position detection value c of the motor 3 and the position command a can be corrected so as to coincide with each other, so that the position command and the position command can be corrected by updating the position correction amount described in FIG. It is possible to prevent a deviation from occurring between the detected value and the detected value.

  As described above, according to the seventh embodiment, as in the sixth embodiment, the position within one rotation of the position command and the position detection value can be matched without the control input exceeding the limit range. Therefore, it is possible to perform positioning without being displaced. Similarly, it is possible to perform an indexing operation (orientation operation) required at the time of tool change.

Embodiment 8 FIG.
In the eighth embodiment, a correction method when there is a dead time such as a communication delay or a control cycle is different in the first to seventh embodiments. Here, for convenience of explanation, a correction method when there is a dead time such as communication delay using the motor drive control device 1b shown in FIG. 2 (Embodiment 2) will be described.

  That is, as described above, the command value shaping unit 6b in the motor drive control device 1b includes a part that calculates the corrected position command from the position command, a part that calculates the corrected position command and the position detection value, and performs feedback processing. It can be separated into two.

  Therefore, part of the processing of the motor drive control device 1b (command value shaping processing, position correction amount subtraction processing) is performed by a position command generation device such as a numerical control device (NC) or a motion controller, and the remaining processing (feedback processing). ) Is performed by a motor drive control device such as an amplifier, a correction method in the case where a communication delay exists between the position command generation device 2 and the motor drive control device 1b will be described.

  FIG. 8 is a block diagram showing the configuration of the motor drive control apparatus according to Embodiment 8 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 eighth embodiment.

  In the motor drive control device 1h according to the eighth embodiment shown in FIG. 8, in the configuration shown in FIG. 2 (the second embodiment), the position detector 2, the position correction amount calculation unit 5b, and the reference position deviation calculation unit 4a A wasted time correction unit 21 is provided because there is a wasted time between them, and a wasted time correcting unit 22 is provided between the correction position command j calculated by the subtractor 11a and a subtractor 11b because there is a wasted time. ing.

The dead time correction units 21 and 22 are arranged on the communication path and perform the same operation. That is, as shown in the following equation (9), the dead time correction unit 21 adds the product of the speed VFB of the motor 3 (differential value of the position detection value PFB) and the correction time TC to the position detection value PFB. The position detection value PFB ′ after dead time correction (position detection value p after dead time correction shown in FIG. 8) is output.
PFB ′ = PFB + VFB × TC (9)

When the position detection value PFB is a signal including the dead time TD, the dead time can be corrected by calculating Equation (9) using the correction time TC as the dead time TD. When the position detection value PFB is a discrete value, the speed VFB of the motor 3 is a difference value of the position detection value PFB, and can be calculated by the following equation (10).
VFB (t) = PFB (t) −PFB (t−1) (10)
In Equation (10), t is a time obtained by multiplying the interpolation cycle of the control system by a constant.

  The dead time correction unit 22 can also output the corrected position command r after correcting the dead time by correcting the corrected position command j by performing the dead time correction on the corrected position command j.

  As described above, according to the eighth embodiment, the position correction amount calculation unit 5b calculates the position deviation while the position detection value is delayed by the dead time, and the reference position deviation calculation unit 4a calculates the reference position deviation d. Even in the case of calculation, it is possible to reduce the influence of the dead time, and it is possible to accurately command the command value with respect to the control input restriction.

  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 eighth embodiment is not limited to the location where the dead time exists, and can also be applied to cases where dead time is included inside and outside the motor drive control device.

Embodiment 9 FIG.
In the first to eighth embodiments, the method of correcting the position deviation so that the control input is equal to or less than the control input limit has been described using the control input calculation unit 7 as a feedback compensator. In the ninth embodiment, a position correction method that is not limited to the category of feedback control will be described.

  FIG. 9 is a block diagram showing a configuration of a motor drive control device according to Embodiment 9 of the present invention. In FIG. 9, the same reference numerals are given to the same or equivalent components as those shown in FIG. 1 (Embodiment 1). Here, the description will be focused on the portion related to the ninth embodiment.

  In the motor drive control device 1i according to the ninth embodiment shown in FIG. 9, in the configuration shown in FIG. 1 (Embodiment 1), the reference position deviation calculation unit 4b with a different sign and the control input with the same sign changed. A calculation unit 7b is provided.

  The reference position deviation calculation unit 4b incorporates a feedforward compensator 27, and prepares the feedforward compensator 27 in advance by calculating a feedforward control input based on the position command a. Then, a reference position deviation d is calculated using a value obtained by subtracting the calculated feedforward control input from the reference control input b and the position detection value c.

  The control input calculator 7 b includes a feedback compensator 23, a feedforward compensator 24, and an adder 25. The feedback compensator 23 calculates a feedback control input based on the corrected position deviation g, and the feedforward compensator 24 calculates a feedforward control input based on the position command a. The adder 25 adds the feedback control input and the feedforward control input, and outputs the addition result as a control input to the motor 3. The feedforward compensator 27 built in the reference position deviation calculation unit 4b has the same configuration as the feedforward compensator 24.

  The above is a description using the two-degree-of-freedom control, but the control input (feedforward control input) calculated by the feedforward compensator 24 is used as the control input (feedback control input) calculated by the feedback compensator 23. ) Can be regarded as a correction value (control input correction value).

  Here, the control input correction value is not limited to the feed-forward control input of the two-degree-of-freedom control, but various correction functions for calculating the control input correction amount according to the characteristics of the machine (generated on the drive system sliding surface) A correction amount calculated by a correction for eliminating the influence of friction, a correction for the influence of gravity, or the like may be used. The control input correction amount may be a combination of two or more types of correction functions and control methods.

  As described above, according to the ninth embodiment, the control input calculation unit adds the control input correction value (feedforward control input) to the control input (feedback control input) calculated from the feedback compensator, so that the motor Therefore, position correction not limited to the category of feedback control can be performed.

  As described above, the motor drive control device according to the present invention is useful as a motor drive control device that can reliably prevent control performance deterioration and control system instability due to saturation of control input.

1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i Motor drive control device 2 Position command generation device 3 Motor (servo motor)
4a, 4b Reference position deviation calculation unit 5a, 5b, 5c Position correction amount calculation unit 6a, 6b Command value shaping unit 7 Control input calculation unit 8 Control input limit unit 9 Position detector 15a, 15b Modified position deviation selection unit 16, 18 , 20 Subtractors 17a, 17b Position correction amount update unit 19 Position correction unit within one rotation 21, 22 Dead time correction unit 23 Feedback compensator 24, 27 Feed forward compensator 25 Adder

Claims (10)

In a motor drive control device in which a control input to a motor that performs drive control based on a position command is limited,
Reference position for calculating a reference position deviation for the control input to match 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 A deviation calculating unit;
The absolute value of the position deviation, which is the difference between the position command and the detected position detection value of the motor, is compared with the absolute value of the reference position deviation, and the absolute value of the reference position deviation is the absolute value of the position deviation. Is smaller than the absolute value of the position deviation, the position correction amount for correcting the position deviation is calculated and output so that the position deviation matches the reference position deviation. Is also larger, a position correction amount calculation unit that outputs the position correction amount for correcting the position deviation as zero, and
A command value shaping unit having a corrected position deviation generated by subtracting the position correction amount from the position deviation as an input signal of the control input calculating unit;
A motor drive control device comprising: A position correction amount update unit that calculates the updated position correction amount by adding the position correction amount to the previous value of the updated position correction amount that is output;
The position correction amount calculation unit, instead of the position deviation, as a corrected position deviation obtained by subtracting the updated position correction amount from the position deviation,
The command value shaping unit outputs the corrected position deviation as a value obtained by subtracting the updated position correction amount from the position deviation.
The motor drive control device according to claim 1. In a motor drive control device in which a control input to a motor that performs drive control based on a position command is limited,
Reference position for calculating a reference position deviation for the control input to match 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 A deviation calculating unit;
Of the position deviation, which is the difference between the position command and the detected position value of the motor, and the reference position deviation, the smaller absolute value is selected as the corrected position deviation to be input to the control input calculation unit. A correction position selection section;
A motor drive control device comprising: The updated position correction amount is calculated by adding the difference between the corrected position deviation and the corrected position deviation obtained by subtracting the updated position correction amount from the position deviation to the previous value of the updated position correction amount that is output. It further includes a position correction amount update unit,
The position correction amount selection unit, instead of the position deviation, as the corrected position deviation,
The motor drive control apparatus according to claim 3. By adding / subtracting the position correction amount for one rotation from the updated position correction amount, a position correction amount of less than one rotation is obtained, and the position correction amount of less than one rotation is subtracted from the updated position correction amount for one rotation. It further includes a one-revolution inner position correction unit that outputs a position correction amount after the inner position correction,
The position correction amount update unit replaces the previous value of the post-update position correction amount with the position correction amount after position correction within one rotation,
5. The motor drive control device according to claim 2, wherein the corrected position deviation is a value obtained by subtracting the position correction amount after position correction within one rotation from the position deviation. The one rotation internal position correction unit is
If the post-update position correction amount matches the previous value, and if the position correction amount of less than one rotation is other than 0, the post-update position with the difference between the post-correction position deviation and the reference position deviation as an upper limit The motor drive control device according to claim 5, wherein the position correction amount after position correction for one rotation is subtracted from a correction amount. The command value shaping unit
The value obtained by subtracting the position correction amount from the position command is used as a corrected position command, and the corrected position deviation is output by subtracting the position detection value from the corrected position command. Motor drive control device. A value obtained by multiplying the position detection value by a first correction time and the position detection value are added to time-correct the position detection value,
The motor drive control device according to claim 7, wherein the correction position command is time-corrected by adding a value obtained by multiplying the correction position command by a second correction time and the correction position command. The control input calculation unit controls a sum of an output of a feedback compensator that calculates a feedback control input based on the corrected position deviation and an output of a feedforward compensator that calculates a feedforward control input based on the position command. When outputting as input,
The reference position deviation calculation unit calculates the reference position deviation based on a value obtained by subtracting an output of a built-in feedforward compensator from the reference control input and the position detection value. The motor drive control device according to any one of 8.   The motor drive control device according to claim 1, wherein the reference control input is a limit value with respect to the control input or a multiple value of the limit value.

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