WO2025013209A1 - Control device and computer-readable recording medium - Google Patents

Abstract

In the present invention, inversion correction processing is performed without adding unnecessary delays in instructions or the like.　A control device (1) according to the present disclosure is provided with: a program analysis unit (100) for analyzing a control program that instructs an industrial machine to operate and for generating a movement instruction; an interpolation unit (110) for, on the basis of the movement instruction, creating first movement instruction data of interpolation periods pertaining to respective axes of the industrial machine; an inversion detection unit (120) for detecting the timing at which a direction of movement in a predetermined axis inverts on the basis of the first movement instruction data calculated by the interpolation unit; an acceleration/deceleration unit (130) for creating second movement instruction data obtained by performing predetermined acceleration/deceleration processing on the first movement instruction data; and a servo control unit (140) for controlling a motor related to each of the axes of the industrial machine in conformity with the second movement instruction data. The servo control unit executes inversion correction processing on the second movement instruction data in accordance with the timing at which the direction of movement in the predetermined axis inverts as detected by the inversion detection unit.

Description

Control device and computer-readable recording medium

This disclosure relates to a control device and a computer-readable recording medium.

When the direction of movement of the feed axis of a machine tool changes, the direction of the frictional force reverses. The twisting direction of the mechanism also reverses. If the effects of this reversal in the direction of the frictional force and the reversal in the twisting direction are not eliminated, the movement path of the feed axis will deviate from the command path. Various methods have been devised to correct this phenomenon (for example, Patent Documents 1 and 2, etc.).

JP 2012-093989 A Japanese Patent Application Publication No. 05-011824

When making corrections that take into account the effects of reversals in the direction of friction or twist, in order to minimize the effects, it is necessary to start correcting the speed command or torque command a little before the feed axis actually reverses. For this reason, it is necessary to know in advance that the feed axis movement command will reverse. For example, there is a method of delaying the transmission of the movement command to the feed axis control unit for a certain amount of time, detecting the reversal earlier within the delay time, and adjusting the timing of the correction. There is also a method of starting the reversal correction command ahead of the time when the motor reverses. However, no matter which method is used, various problems will occur, such as unnecessary delays in responding to speed override changes and emergency stop requests.
Therefore, a technique for performing inversion correction processing without adding unnecessary command delays is desired.

The industrial machinery control device disclosed herein solves the above problem without delaying commands by detecting reversals of movement commands and determining the reversal state before the acceleration/deceleration processing applied to each axis.

An aspect of the present disclosure is a control device that includes a program analysis unit that analyzes a control program that commands the operation of an industrial machine and generates a movement command; an interpolation unit that creates first movement command data for each interpolation period related to each axis of the industrial machine based on the movement command; a reversal detection unit that detects the timing at which the movement direction in a predetermined axis is reversed based on the first movement command data calculated by the interpolation unit; an acceleration/deceleration unit that creates second movement command data by performing a predetermined acceleration/deceleration process on the first movement command data calculated by the interpolation unit; and a servo control unit that controls a motor related to each axis of the industrial machine in accordance with the second movement command data, and the servo control unit executes a reversal correction process on the second movement command data in accordance with the timing at which the movement direction in the predetermined axis detected by the reversal detection unit is reversed.

FIG. 2 is a schematic hardware configuration diagram of a control device according to the first embodiment. FIG. 2 is a block diagram showing schematic functions of a control device according to the first embodiment. 11 is a graph showing an example of movement command data related to a predetermined axis generated by an interpolation unit. 11 is a graph showing an example of movement command data for each interpolation period that has been subjected to acceleration/deceleration processing and that is created by an acceleration/deceleration unit. 11 is a graph showing an example in which a servo control unit outputs inversion correction command data.

Below, an embodiment of the present invention will be described with reference to the drawings. In the following description, components having the same or similar functions will be given the same reference numerals. Furthermore, duplicate descriptions of those components may be omitted.

In this application, "based on XX" means "based on at least XX," and includes cases where it is based on other elements in addition to XX. Furthermore, "based on XX" is not limited to cases where XX is used directly, but also includes cases where it is based on XX that has been calculated or processed. "XX" is any element (for example, any information).

[First embodiment]
1 is a schematic hardware configuration diagram showing the main parts of a control device according to an embodiment of the present invention. The control device 1 of the present invention can be implemented as a control device that controls industrial machines such as machine tools and robots that have moving objects that move when driven by a motor. In the following, the control device 1 that controls a machine tool that processes a workpiece by controlling the relative positions of a tool and a workpiece will be described as an example.

The CPU 11 provided in the control device 1 of the present invention is a processor that controls the entire control device 1. The CPU 11 reads the system program stored in the ROM 12 via the bus 22, and controls the entire control device 1 in accordance with the system program. The RAM 13 temporarily stores temporary calculation data, display data, and various data input from outside.

The non-volatile memory 14 is composed of, for example, a memory backed up by a battery (not shown) or an SSD (Solid State Drive), and retains its memory state even when the power to the control device 1 is turned off. The non-volatile memory 14 stores control programs and data read from an external device 72 via the interface 15, data and control programs input via the input device 71, and various data acquired from the industrial machine 3. The control programs and data stored in the non-volatile memory 14 may be expanded in the RAM 13 when executed/used. In addition, various system programs such as well-known analysis programs are written in advance in the ROM 12.

The interface 15 is an interface for connecting the CPU 11 of the control device 1 to an external device 72 such as a USB memory, a Compact Flash (registered trademark), or an SD card. For example, control programs and various data used to control the industrial machine 3 can be read from the external device 72. In addition, the control programs and various data edited in the control device 1 can be stored in the external device 72. The PLC (Programmable Logic Controller) 16 outputs signals to the industrial machine 3 and its peripheral devices (for example, tool changers, actuators such as robots, sensors attached to the industrial machine 3, etc.) via the I/O unit 17 and controls them using a sequence program built into the control device 1. The PLC 16 also receives signals from various switches on an operation panel installed on the main body of the industrial machine 3 and from peripheral devices, etc., and passes them to the CPU 11 after performing the necessary signal processing.

The display device 70 displays various data loaded into the memory, data obtained as a result of executing control programs and system programs, etc., output via the interface 18. In addition, the input device 71, which is composed of a keyboard, pointing device, etc., passes commands and data based on operations by the operator to the CPU 11 via the interface 19.

The interface 20 is an interface for connecting the CPU 11 of the control device 1 to a wired or wireless network 5. The network 5 may communicate using technologies such as serial communication such as RS-485, Ethernet (registered trademark), optical communication, wireless LAN, Wi-Fi (registered trademark), Bluetooth (registered trademark), etc. The network 5 is connected to other industrial machines 4, fog computers 6, cloud servers 7, etc., and exchanges data with the control device 1.

The axis control circuit 30 for controlling the drive axis of the industrial machine 3 receives a drive axis position command from the CPU 11 and outputs a command for the drive axis to the servo amplifier 40. The servo amplifier 40 receives this command and drives the servo motor 50, which is the drive axis, to move each part of the industrial machine 3 along each axis. Each servo motor 50 has a built-in position detector, and feeds back a position feedback signal from this position detector to the axis control circuit 30. The axis control circuit 30 performs feedback control of the servo motor 50 based on this position feedback signal. Note that in the hardware configuration diagram of FIG. 1, only one axis control circuit 30, servo amplifier 40, and servo motor 50 are shown, but in reality, there are as many as the number of axes of the industrial machine 3 to be controlled. For example, when controlling a general machine tool with three linear axes, three sets of axis control circuits 30, servo amplifiers 40, and servo motors 50 are prepared to relatively move the spindle to which the tool is attached and the workpiece in the directions of the three linear axes (X-axis, Y-axis, and Z-axis).

The spindle control circuit 60 receives a spindle rotation command and outputs a spindle speed signal to the spindle amplifier 61. The spindle amplifier 61 receives this spindle speed signal and rotates the spindle motor 62 of the industrial machine 3 at the commanded rotation speed to drive the spindle. A position coder 63 is connected to the spindle motor 62. The position coder 63 outputs a feedback pulse in synchronization with the rotation of the spindle, and the feedback pulse is read by the CPU 11.

FIG. 2 is a schematic block diagram showing the functions of the control device 1 according to the first embodiment of the present disclosure. Each function of the control device 1 according to this embodiment is realized by the CPU 11 of the control device 1 shown in FIG. 1 executing a system program and controlling the operation of each part of the control device 1.

The control device 1 of this embodiment includes a program analysis unit 100, an interpolation unit 110, a reversal detection unit 120, an acceleration/deceleration unit 130, and a servo control unit 140. In addition, the RAM 13 to the non-volatile memory 14 of the control device 1 store a control program 200 for controlling the industrial machine 3.

The program analysis unit 100 sequentially reads out blocks of the control program and analyzes the read out blocks. Then, based on the analysis results, it creates a movement command related to a path for moving the drive unit equipped in the industrial machine 3. The movement command related to the path created by the program analysis unit 100 takes into account, for example, offsets related to tools. The program analysis unit 100 outputs the created movement command to the interpolation unit 110.

The interpolation unit 110 performs an interpolation process to calculate the movement amount per interpolation period for each axis of the industrial machine 3 based on the movement command created by the program analysis unit 100. Then, it creates movement command data indicating the movement amount per interpolation period for each axis. The interpolation unit 110 outputs the created movement command data per interpolation period to the inversion detection unit 120 and the acceleration/deceleration unit 130.

The reversal detection unit 120 detects when the direction of movement along each axis of the drive unit of the industrial machine 3 is reversed, based on the movement command data for each interpolation cycle created by the interpolation unit 110. The reversal detection unit 120 notifies the servo control unit 140 of the timing when the direction of movement along a specific axis is reversed.

The acceleration/deceleration unit 130 performs post-interpolation acceleration/deceleration processing to adjust the amount of movement for each interpolation cycle for the movement command data for each interpolation cycle created by the interpolation unit 110. The post-interpolation acceleration/deceleration processing performed by the acceleration/deceleration unit 130 suppresses the magnitude of the first-order differential value in the movement of the drive unit along a specified axis based on the movement command data by, for example, applying an average filter to the movement command data for each interpolation cycle. The movement command data that has been subjected to post-interpolation acceleration/deceleration processing is accelerated and decelerated over a period of a predetermined post-interpolation acceleration/deceleration time constant. The acceleration/deceleration unit 130 outputs the movement command data for each interpolation cycle that has been subjected to acceleration/deceleration processing to the servo control unit 140.

The servo control unit 140 controls each servo motor 50 so that the driving unit of the industrial machine 3 moves along each axis based on the movement command data for each interpolation period input from the acceleration/deceleration unit 130. When the reversal detection unit 120 notifies the timing of the reversal of the direction of movement along a specific axis, the servo control unit 140 starts the reversal correction process for the specific axis according to that timing. The reversal correction process is a process of outputting the reversal correction command data at the same time as outputting the movement command data to the servo motor 50. This reversal correction command data may correct the speed command. It may also correct the torque command. Note that the correction amount of the reversal correction command data differs depending on the configuration of the industrial machine 3 and the structure of the members used for the axes, so an appropriate correction amount can be obtained by conducting experiments in advance. In machine tools, the effect of the reversal correction has been confirmed by the accuracy of the circular shape, so there is also a method of issuing a circular command for one or several revolutions for two feed axes, applying repetitive control to this, and calculating the reversal correction amount from the control data after the position deviation has converged.

The operation from when the reversal detection unit 120 detects that the moving direction of a predetermined axis is reversed to when the servo control unit 140 outputs the reversal correction command data will be described below with reference to FIGS.
FIG. 3 is a graph showing an example of movement command data for a predetermined axis created by the interpolation unit 110. In FIG. 3, the movement command data for each interpolation cycle is represented by a white bar in the bar graph. The height of the white bar represents the movement amount in that interpolation cycle. In the example of FIG. 3, movement command data is created for each interpolation cycle T _itp . Before time t _n , movement command data is created so as to move by a movement amount L _itp for each interpolation cycle T _itp . Furthermore, after time t _n , movement command data is created so as to move by a movement amount -L _itp for each interpolation cycle T _itp . When such movement command data is created, the reversal detection unit 120 detects that the movement direction in the predetermined axis is reversed at time t _n .

Fig. 4 is a graph showing an example of the movement command data for each interpolation period that has been subjected to acceleration/deceleration processing created by the acceleration/deceleration unit 130. The movement command data in Fig. 4 is obtained by performing post-interpolation acceleration/deceleration processing on the movement command data exemplified in Fig. 3. In the example of Fig. 4, the movement command data around time _tn is filtered using an average value, so that the speed is decelerated over a period of time equal to the post-interpolation acceleration/deceleration time constant τ, and then the movement direction is reversed. The movement amount in the interpolation period becomes 0 at time _tp . It is at this time _tp that the movement direction related to the actual axis is reversed.

FIG. 5 is a graph showing an example of the servo control unit 140 outputting the inversion correction command data. In FIG. 5, the inversion correction command data is shown by black bars in the bar graph. The servo control unit 140 is notified by the inversion detection unit 120 that the movement direction of a specific axis will be inverted at time t _n in the movement command data created by the interpolation unit 110. Then, as a result of the acceleration/deceleration process by the acceleration/deceleration unit 130, the axis actually inverts at time t _p . The servo control unit 140 estimates the period from time t _n to time t _p as the inversion correction process start period T _icp . If it is assumed that the acceleration (deceleration) is constant before and after the movement direction is inverted, the inversion correction process start period T _icp is τ/2. The servo control unit 140 starts the inversion correction process at any time between time t _n and the inversion correction process start period T _icp . As for the timing to start the inversion correction process, it is sufficient to determine in advance by experiment or the like how long before the time t _p when the axis actually inverts after the acceleration/deceleration process, the inversion correction process should be started. For example, the timing at which the position deviation at the time of reversal is smallest may be examined in advance by an experiment or the like. Since the timing at which the position deviation is smallest approaches time _tp as the acceleration at the time of reversal increases, the timing may be examined under a plurality of conditions with different accelerations at the time of reversal, and the start timing of the reversal correction process may be obtained for each of the different conditions according to the acceleration at the time of reversal. For example, the acceleration start timing may be determined so as to be proportional to the acceleration at the time of reversal of the moving direction or the square root of the acceleration at the time of reversal of the moving direction. The servo control unit 140 creates reversal correction command data taking into account the movement command data, and superimposes the data on the movement command data as a speed command to control the speed of the servo motor 50. In FIG. 5, the speed command of the reversal correction command data is shown as a correction amount for each interpolation period.

The control device 1 according to this embodiment, which is configured as described above, detects reversals of movement commands and determines the reversal state before the acceleration/deceleration processing normally applied to each axis. By taking advantage of the delay caused by this acceleration/deceleration processing, corrections can be made slightly before reversals occur without adding a large buffer for movement commands, thereby reducing position deviations during reversals.

As a modified example of the control device 1 according to the present embodiment, the servo control unit 140 may increase or decrease the estimated value of the inversion correction process start period T _icp according to the acceleration (deceleration) before and after the movement direction of a predetermined axis is reversed. For this purpose, the inversion detection unit 120 may notify the servo control unit 140 of the acceleration at the time of inversion and the acceleration after inversion, or the transition of the acceleration for a predetermined time after inversion, when the command speed before and after the inversion of the movement direction is different, if the acceleration/deceleration unit 130 applies an averaging filter to the movement command data for each interpolation command, the period until the movement amount becomes 0 is not simply τ/2. For example, when the command speed after the inversion of the movement direction is large, the period until the movement amount becomes 0 in the movement command data after the acceleration/deceleration process is longer than τ/2. Also, when the command speed after the inversion of the movement direction is small, the period until the movement amount becomes 0 in the movement command data after the acceleration/deceleration process is shorter than τ/2. Therefore, the servo control unit 140 estimates the inversion correction process start period T _icp to be smaller than τ/2 when the acceleration (deceleration) after the movement direction of a predetermined axis is reversed is larger than the previous acceleration (deceleration), and estimates the inversion correction process start period T _icp to be smaller than τ/2 when the acceleration (deceleration) is smaller. For example, the inversion correction process start period T _icp may be estimated by the following formula 1. In formula 1, τ is the post-interpolation acceleration/deceleration time constant, and A is the square root of the value obtained by dividing the acceleration before the reversal by the acceleration after the reversal. The acceleration before and after the reversal may be calculated appropriately based on the transition of the movement amount before and after the reversal of the movement command data created by the interpolation unit 110 and the algorithm of the acceleration/deceleration process used by the acceleration/deceleration unit 130. By configuring in this way, it becomes possible to start the inversion correction process at an appropriate timing.

As another variation of the control device 1 according to this embodiment, the servo control unit 140 may observe the progress of the movement command data created by the interpolation unit 110 after the timing at which the direction of movement along a specified axis notified by the reversal detection unit 120 is reversed, and recalculate the reversal timing if the acceleration increases or decreases. At this time, the time from when the movement amount per interpolation period in the movement command data created by the interpolation unit 110 becomes a specified value until the speed after acceleration/deceleration after interpolation becomes a specified value may be measured at one or more points, and the reversal timing may be calculated based on the measured time.

As another modification of the control device 1 according to the present embodiment, the servo control unit 140 may correct the correction amount for each interpolation period of the inversion correction command data when the timing of reversal of the movement direction of a predetermined axis in the movement command data after the acceleration/deceleration process by the acceleration/deceleration unit 130 deviates from the end point of the estimated inversion correction process start period T _icp . For example, if the actual inversion timing is later than the end point of the estimated inversion correction process start period T _icp , the correction amount for each interpolation period by the inversion correction command data may be reduced, and if the actual inversion timing is earlier, the correction amount for each interpolation period by the inversion correction command data may be increased. At this time, the integrated value of the correction amount by the inversion correction command data is adjusted so as to match. By configuring in this way, it becomes possible to execute an appropriate inversion correction process even if the estimated inversion timing and the actual inversion timing are deviated.

Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments, without departing from the gist of the invention, or without departing from the idea and intent of the present disclosure derived from the contents described in the claims and their equivalents. For example, in the above-mentioned embodiments, the order of each operation and the order of each process are shown as examples, and are not limited to these. The same applies when numerical values or formulas are used in the explanation of the above-mentioned embodiments.

Below, notes relating to the embodiments of the present disclosure are provided.
(Appendix 1)
A control device (1) according to one aspect of the present disclosure includes a program analysis unit (100) that analyzes a control program (200) that commands the operation of an industrial machine (3) and generates a movement command; an interpolation unit (110) that creates first movement command data for each interpolation period related to each axis of the industrial machine (3) based on the movement command; an inversion detection unit (120) that detects a timing at which a movement direction in a predetermined axis is reversed based on the first movement command data calculated by the interpolation unit (110); an acceleration/deceleration unit (130) that creates second movement command data by performing a predetermined acceleration/deceleration process on the first movement command data calculated by the interpolation unit (110); and a servo control unit (140) that controls a motor related to each axis of the industrial machine in accordance with the second movement command data, and the servo control unit (140) executes an inversion correction process on the second movement command data in accordance with the timing at which the movement direction in the predetermined axis detected by the inversion detection unit (120) is reversed.

(Appendix 2)
In a control device (1) according to another aspect of the present disclosure, the servo control unit (140) starts an inversion correction process during an inversion process start period from the timing at which the movement direction in a specified axis detected by the inversion detection unit (120) is reversed to the timing at which the movement direction in the specified axis is reversed in the second movement command data.
(Appendix 3)
In a control device (1) according to another aspect of the present disclosure, the servo control unit (140) estimates the inversion process start period to be half the time of the post-interpolation acceleration/deceleration time constant set for the axis.
(Appendix 4)
In a control device (1) according to another aspect of the present disclosure, when the acceleration differs before and after the timing at which the direction of movement on a specified axis is reversed, the servo control unit (140) increases or decreases the estimated value of the reversal processing start period in accordance with the acceleration before and after the reversal.
(Appendix 5)
In a control device (1) according to another aspect of the present disclosure, the servo control unit (140) estimates the inversion processing start period to be longer than half the post-interpolation acceleration/deceleration time constant when the acceleration after reversal decreases compared to the acceleration before the timing at which the movement direction on a specified axis is reversed, and estimates the inversion processing start period to be shorter than half the post-interpolation acceleration/deceleration time constant when the acceleration after reversal increases.

ただし、Ｔicpは反転補正処理開始期間、τは補間後加減速時定数、Ａは反転前の加速度を反転後の加速度で除算した値の平方根を示す。
（付記７）
　本開示の他の態様による制御装置（１）は、前記サーボ制御部（１４０）は、移動方向が反転する後の前記第１の移動指令データの推移を観測し、前記第１の移動指令データの推移に基づいて、反転タイミングを再計算する。
（付記８）
　本開示の他の態様による制御装置（１）は、前記サーボ制御部（１４０）は、減速時に補間後加減速前の速度が所定の値になってから、補間後加減速後の速度が所定の値になるまでの時間を１点、もしくは複数点計測し、反転タイミングの再計算に利用する。
（付記９）
　本開示の他の態様による制御装置（１）は、前記サーボ制御部（１４０）は、前記第２の移動指令データにおける所定の軸の移動方向が反転するタイミングから予め定めた所定の時間先行して反転補正処理を開始する。 (Appendix 6)
In a control device (1) according to another aspect of the present disclosure, the servo control unit (140) estimates the inversion process start period using the following formula 1.

where Ticp is the inversion correction process start period, τ is the post-interpolation acceleration/deceleration time constant, and A is the square root of the value obtained by dividing the acceleration before inversion by the acceleration after inversion.
(Appendix 7)
In a control device (1) according to another aspect of the present disclosure, the servo control unit (140) observes the transition of the first movement command data after the movement direction is reversed, and recalculates the reversal timing based on the transition of the first movement command data.
(Appendix 8)
In a control device (1) according to another aspect of the present disclosure, the servo control unit (140) measures the time from when the speed before post-interpolation acceleration/deceleration becomes a predetermined value during deceleration until when the speed after post-interpolation acceleration/deceleration becomes a predetermined value at one or more points, and uses the measured time to recalculate the reversal timing.
(Appendix 9)
In a control device (1) according to another aspect of the present disclosure, the servo control unit (140) starts an inversion correction process a predetermined time prior to the timing at which the movement direction of a specified axis in the second movement command data is reversed.

(Appendix 10)
A control device (1) according to another aspect of the present disclosure determines the predetermined time period so that the position deviation during reversal is minimized.
(Appendix 11)
In a control device (1) according to another aspect of the present disclosure, the specified time is determined based on a plurality of conditions in which the acceleration at the time of reversal is different, and is determined so as to be proportional to the acceleration of a specified axis at the time of reversal or the square root of that acceleration.
(Appendix 12)
A control device (1) according to another aspect of the present disclosure adjusts, when the timing at which the movement direction of a specified axis in the second movement command data is reversed deviates from the estimated end point of the reversal processing start period, to decrease the correction amount for each interpolation period in the reversal correction process if the estimated end point is early, or to increase the correction amount for each interpolation period in the reversal correction process if the estimated end point is late.
(Appendix 13)
A control device (1) according to another aspect of the present disclosure adjusts the amount of correction for each interpolation cycle so that integrated values of the amounts of correction in the inversion correction process match.
(Appendix 14)
In a control device (1) according to another aspect of the present disclosure, the servo control unit (140) notifies at least one of the acceleration when the direction of movement of a specified axis is reversed and the change in acceleration over a specified period of time after the reversal.

(Appendix 15)
A computer-readable recording medium according to one aspect of the present disclosure records a program that causes a computer to function as a program analysis unit (100) that analyzes a control program (200) that commands the operation of an industrial machine (3) and generates a movement command; an interpolation unit (110) that creates first movement command data for each interpolation period related to each axis of the industrial machine (3) based on the movement command; an inversion detection unit (120) that detects the timing at which the movement direction in a predetermined axis is reversed based on the first movement command data calculated by the interpolation unit (110); an acceleration/deceleration unit (130) that creates second movement command data by performing a predetermined acceleration/deceleration process on the first movement command data calculated by the interpolation unit (110); and a servo control unit (140) that controls a motor related to each axis of the industrial machine in accordance with the second movement command data, and the servo control unit (140) records a program that causes a computer to function as: a program analysis unit (100) that analyzes a control program (200) that commands the operation of an industrial machine (3) and generates a movement command;

Reference Signs List 1 Control device 3 Industrial machine 4 Industrial machine 5 Network 6 Fog computer 7 Cloud server 11 CPU
12 ROM
13 RAM
14 Non-volatile memory 15, 18, 19, 20 Interface 16 PLC
17 I/O unit 22 Bus 30 Axis control circuit 40 Servo amplifier 50 Servo motor 60 Spindle control circuit 61 Spindle amplifier 62 Spindle motor 63 Position coder 70 Display device 71 Input device 72 External device 100 Program analysis section 110 Interpolation section 120 Reverse rotation detection section 130 Acceleration/deceleration section 140 Servo control section 200 Control program

Claims (15)

a program analysis unit that analyzes a control program that commands the operation of the industrial machine and generates a movement command;
an interpolation unit that creates first move command data for each interpolation period for each axis of the industrial machine based on the move command;
an inversion detection unit that detects a timing at which a movement direction in a predetermined axis is inverted based on the first movement command data calculated by the interpolation unit;
an acceleration/deceleration unit that generates second movement command data by performing a predetermined acceleration/deceleration process on the first movement command data calculated by the interpolation unit;
a servo control unit that controls a motor associated with each axis of the industrial machine in accordance with the second movement command data;
Equipped with
the servo control unit executes an inversion correction process for the second movement command data in response to a timing at which the movement direction in the predetermined axis detected by the inversion detection unit is inverted.
Control device. the servo control unit starts an inversion correction process during an inversion process start period from a timing at which the movement direction in the predetermined axis detected by the inversion detection unit is inverted to a timing at which the movement direction in the predetermined axis is inverted in the second movement command data.
The control device according to claim 1 . The servo control unit estimates the inversion process start period to be half the time of a post-interpolation acceleration/deceleration time constant set for the axis.
The control device according to claim 2. When the acceleration is different before and after the timing when the moving direction in a predetermined axis is reversed, the servo control unit increases or decreases the estimated value of the reversal process start period according to the acceleration before and after the reversal.
The control device according to claim 2. the servo control unit estimates the inversion process start period to be longer than half the time of the post-interpolation acceleration/deceleration time constant when the acceleration after the reversal decreases compared to the acceleration before the timing of the reversal of the moving direction on a predetermined axis, and estimates the inversion process start period to be shorter than half the time of the post-interpolation acceleration/deceleration time constant when the acceleration after the reversal increases.
The control device according to claim 4. The servo control unit estimates the inversion process start period using the following formula 1:
The control device according to claim 5.

where T _icp is the inversion correction processing start period, τ is the post-interpolation acceleration/deceleration time constant, and A is the square root of the value obtained by dividing the acceleration before inversion by the acceleration after inversion. the servo control unit observes a transition of the first movement command data after the movement direction is reversed, and recalculates a reversal timing based on the transition of the first movement command data.
The control device according to any one of claims 3 to 6. The servo control unit measures a time from when the speed before the post-interpolation acceleration/deceleration becomes a predetermined value during deceleration until when the speed after the post-interpolation acceleration/deceleration becomes a predetermined value at one point or at multiple points, and uses the time to recalculate the reversal timing.
The control device according to claim 7. the servo control unit starts an inversion correction process a predetermined time prior to a timing at which a movement direction of a predetermined axis in the second movement command data is reversed.
The control device according to claim 1 . The predetermined time is determined so as to minimize the position deviation during reversal.
The control device according to claim 9. The predetermined time is determined based on a plurality of conditions having different accelerations at the time of reversal, and is determined to be proportional to the acceleration of a predetermined axis at the time of reversal or the square root of the acceleration.
The control device according to claim 9. When the timing at which the movement direction of the predetermined axis in the second movement command data is reversed differs from the estimated end point of the reversal process start period, an adjustment is made to reduce the amount of correction for each interpolation period in the reversal correction process if the estimated end point is early, and to increase the amount of correction for each interpolation period in the reversal correction process if the estimated end point is late.
The control device according to any one of claims 3 to 6. The adjustment of the correction amount includes adjusting the magnitude of the correction amount for each interpolation cycle so that an integrated value of the correction amount in the inversion correction process is equal to the integrated value.
The control device according to claim 12. The servo control unit notifies at least one of the acceleration when the moving direction of the predetermined axis is reversed and the change in the acceleration for a predetermined time after the reversal.
The control device according to claim 1. a program analysis unit that analyzes a control program that commands the operation of the industrial machine and generates a movement command;
an interpolation unit that creates first move command data for each interpolation period for each axis of the industrial machine based on the move command;
a reversal detection unit that detects a timing at which a movement direction in a predetermined axis is reversed based on the first movement command data calculated by the interpolation unit;
an acceleration/deceleration unit that generates second movement command data by performing a predetermined acceleration/deceleration process on the first movement command data calculated by the interpolation unit;
a servo control unit that controls a motor associated with each axis of the industrial machine in accordance with the second movement command data;
The computer functions as
the servo control unit executes an inversion correction process for the second movement command data in response to a timing at which the movement direction in the predetermined axis detected by the inversion detection unit is inverted.
A computer-readable recording medium on which a program is recorded.

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