Numerical control device and computer-readable storage medium

Abstract

In a processing machine having a first control axis included in a first system and a second control axis included in a second system, this numerical control device comprises: a relationship information acquisition unit that acquires relationship information indicating a dependency relationship between the first control axis and the second control axis; a state information acquisition unit that acquires state information indicating the state of the processing machine; a correction information acquisition unit that acquires first correction information that indicates a correction amount of the position of the first control axis, on the basis of the state information acquired by the state information acquisition unit; a correction information calculation unit that calculates second correction information that indicates a correction amount of the position of the second control axis, on the basis of the relationship information acquired by the relationship information acquisition unit and the first correction information acquired by the correction information acquisition unit; and a correction unit that corrects the position of the second control axis on the basis of the second correction information calculated by the correction information calculation unit.

Description

Numerical control device and computer-readable storage medium

[0001] The present disclosure relates to a numerical control device and a computer-readable storage medium.

[0002] Conventionally, correction of errors occurring in a processing machine having multiple systems has been performed (for example, see Patent Document 1). The errors are, for example, errors caused by thermal displacement.

[0003] Japanese Patent Application Laid-Open No. 2020-62705

[0004] However, when there is a dependency between the systems, even if the error is corrected for each system, the error may not be corrected appropriately. Therefore, there is a demand for a technology that can perform appropriate error correction even when there is a dependency between multiple systems.

[0005] The numerical control device disclosed herein is for a machining center having a first control axis included in a first system and a second control axis included in a second system, and includes: a relationship information acquisition unit that acquires relationship information indicating the dependency between the first control axis and the second control axis; a status information acquisition unit that acquires status information indicating the status of the machining center; a correction information acquisition unit that acquires first correction information indicating the amount of correction for the position of the first control axis based on the status information acquired by the status information acquisition unit; a correction information calculation unit that calculates second correction information indicating the amount of correction for the position of the second control axis based on the relationship information acquired by the relationship information acquisition unit and the first correction information acquired by the correction information acquisition unit; and a correction unit that corrects the position of the second control axis based on the second correction information calculated by the correction information calculation unit.

[0006] The computer-readable storage medium of the present disclosure stores instructions that cause a computer to execute the following operations in a machining center having a first control axis included in a first system and a second control axis included in a second system: acquire relationship information indicating the dependency between a first control axis and a second control axis; acquire status information indicating the status of the machining center; acquire first correction information indicating the amount of correction for the position of the first control axis based on the acquired status information; calculate second correction information indicating the amount of correction for the position of the second control axis based on the acquired relationship information and the acquired first correction information; and correct the position of the second control axis based on the calculated second correction information.

[0007] 1 is a block diagram showing an example of the hardware configuration of a processing machine; FIG. 2 is a block diagram showing an example of the functions of a numerical control device; FIG. 3 is a diagram for explaining the dependency between systems of a processing machine; FIG. 4 is a diagram for explaining errors; FIG. 5 is an example of a table listing errors in the positional relationship between a spindle and a first tool; FIG. 6 is a flowchart showing an example of processing executed by a numerical control device; FIG. 7 is a diagram for explaining mechanical errors; and FIG. 8 is an example of a table for acquiring mechanical errors of a first tilt head.

[0008] A numerical control device and a computer-readable storage medium according to an embodiment of the present disclosure will be described below with reference to the drawings. In the following description, components having the same or similar functions will be assigned the same reference numerals. Duplicate descriptions of those components may be omitted.

[0009] 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).

[0010] The control axes include, for example, the X-axis, the Y-axis, the Z-axis, the A-axis, the B-axis, and the C-axis.

[0011] Combinations of arrows and letters in the drawings of this application indicate axes in the coordinate system of the processing machine. For example, three mutually perpendicular arrows and the letters "X," "Y," and "Z" attached to each arrow indicate the X-axis, Y-axis, and Z-axis in the Cartesian coordinate system.

[0012] A numerical control device is a device that controls a processing machine. The numerical control device controls the processing machine using, for example, a system program and a processing program. The numerical control device is housed, for example, in an operation panel of the processing machine.

[0013] Examples of the processing machine include a machine tool, a three-dimensional printer, a wire electric discharge machine, a lathe, a machining center, and a multi-tasking machine.

[0014] A processing machine has multiple systems. A system is a collection of control objects controlled by a single command group. One command group is, for example, multiple commands included in a processing program. The control objects include, for example, a spindle and one or more control axes.

[0015] The multiple systems are controlled by different sets of commands. For example, if a processing machine has a first system and a second system, the first system and the second system are controlled using a first machining program and a second machining program, respectively. Specific examples of the systems will be described in detail later.

[0016] 1 is a block diagram showing an example of the hardware configuration of a processing machine 1. The processing machine 1 includes a numerical control device 2, an input / output device 3, a servo amplifier 4, a servo motor 5, a spindle amplifier 6, a spindle motor 7, and auxiliary equipment 8.

[0017] The numerical control device 2 includes, for example, a hardware processor 201 , a bus 202 , a read-only memory (ROM) 203 , a random access memory (RAM) 204 , and a non-volatile memory 205 .

[0018] The hardware processor 201 is a processor that controls the entire numerical control device 2 in accordance with a system program. The hardware processor 201 reads the system program and the like stored in the ROM 203 via the bus 202. The hardware processor 201 is, for example, a CPU (Central Processing Unit) or an electronic circuit.

[0019] The bus 202 is a communication path that connects the various hardware components of the numerical control device 2. The various hardware components of the numerical control device 2 exchange data via the bus 202.

[0020] The ROM 203 is a storage device that stores system programs, etc. The ROM 203 is a computer-readable storage medium.

[0021] The RAM 204 is a storage device that temporarily stores various data and functions as a work area for the hardware processor 201 to process various data.

[0022] The nonvolatile memory 205 is a storage device that retains data even when the power to the numerical control device 2 is turned off. The nonvolatile memory 205 stores, for example, a machining program. The nonvolatile memory 205 is a computer-readable storage medium. The nonvolatile memory 205 is, for example, a battery-backed memory or an SSD (Solid State Drive).

[0023] The numerical control device 2 further includes an interface 206 , an axis control circuit 207 , a spindle control circuit 208 , a PLC (Programmable Logic Controller) 209 , and an I / O unit 210 .

[0024] The interface 206 connects the bus 202 and the input / output device 3. The interface 206 sends various data processed by the hardware processor 201 to the input / output device 3, for example.

[0025] The input / output device 3 receives various data via the interface 206 and displays the various data on a display. The input / output device 3 also receives input of various data and sends the various data via the interface 206 to, for example, the hardware processor 201.

[0026] The input / output device 3 is, for example, a touch panel. When the input / output device 3 is a touch panel, the input / output device 3 is, for example, a capacitive touch panel. The touch panel is not limited to a capacitive touch panel and may be a touch panel of another type. The input / output device 3 is installed in an operation panel (not shown) in which the numerical control device 2 is housed.

[0027] The axis control circuit 207 is a circuit for controlling the servo motor 5. The axis control circuit 207 receives control commands from the hardware processor 201 and sends various commands to the servo amplifier 4 for driving the servo motor 5. The axis control circuit 207 sends, for example, a torque command for controlling the torque of the servo motor 5 to the servo amplifier 4.

[0028] The servo amplifier 4 receives a command from the axis control circuit 207 and supplies a current to the servo motor 5 .

[0029] The servo motors 5 are driven by receiving a current supply from the servo amplifier 4. The servo motors 5 are provided corresponding to each control axis of the processing machine 1. If the processing machine 1 is a machine tool having five axes, the servo motors 5 include, for example, an X-axis servo motor, a Y-axis servo motor, a Z-axis servo motor, an A-axis servo motor, and a C-axis servo motor. In this case, an axis control circuit 207 and a servo amplifier 4 are provided for each servo motor 5.

[0030] The servo motor 5 is connected to, for example, a ball screw that moves a turret. When the servo motor 5 is driven, a structure of the processing machine 1, such as a turret, moves along a predetermined control axis.

[0031] The servo motor 5 has a built-in encoder (not shown) that detects the position and feed rate of the control axis. Position feedback information and speed feedback information indicating the position and feed rate of the control axis detected by the encoder are fed back to the axis control circuit 207. In this way, the axis control circuit 207 performs feedback control of each control axis.

[0032] The spindle control circuit 208 is a circuit for controlling the spindle motor 7. The spindle control circuit 208 receives a control command from the hardware processor 201 and sends a command to the spindle amplifier 6 to drive the spindle motor 7. The spindle control circuit 208 sends, for example, a spindle speed command to the spindle amplifier 6 to control the rotation speed of the spindle motor 7.

[0033] The spindle amplifier 6 receives a command from the spindle control circuit 208 and supplies a current to the spindle motor 7 .

[0034] The spindle motor 7 is driven by receiving a current supplied from the spindle amplifier 6. The spindle motor 7 is connected to the main shaft and rotates the main shaft.

[0035] The PLC 209 is a device that executes a ladder program to control the auxiliary device 8. The PLC 209 sends commands to the auxiliary device 8 via an I / O unit 210.

[0036] The I / O unit 210 is the interface 206 that connects the PLC 209 and the auxiliary device 8. The I / O unit 210 sends commands received from the PLC 209 to the auxiliary device 8.

[0037] The auxiliary device 8 is installed in the processing machine 1 and performs auxiliary operations in the processing machine 1. The auxiliary device 8 operates based on commands received from the I / O unit 210. The auxiliary device 8 may be a device installed in the periphery of the processing machine 1. The auxiliary device 8 is, for example, a tool changer, a cutting fluid injection device, or an opening / closing door drive device.

[0038] 2 is a block diagram showing an example of the functions of the numerical control device 2. The numerical control device 2 controls the operation of each control axis of the processing machine 1 based on a processing program. The numerical control device 2 also controls the rotation of the spindle based on the processing program. In this way, the processing machine 1 processes the workpiece.

[0039] The numerical control device 2 includes, for example, a relationship information acquisition unit 211, a state information acquisition unit 212, a correction information acquisition unit 213, a correction information calculation unit 214, and a correction unit 215. The relationship information acquisition unit 211, the state information acquisition unit 212, the correction information acquisition unit 213, the correction information calculation unit 214, and the correction unit 215 are realized, for example, by the hardware processor 201 performing arithmetic processing using a system program stored in the ROM 203 and various data and machining programs stored in the non-volatile memory 205.

[0040] The relationship information acquisition unit 211 acquires relationship information indicating the dependency between a first control axis included in a first system and a second control axis included in a second system in a processing machine 1 having the first control axis and the second control axis.

[0041] 3 is a diagram illustrating the inter-system dependency of the processing machine 1. The processing machine 1 is, for example, a lathe having a first system and a second system. The first system includes a first turret TA1 and a spindle S. In other words, the first system includes a control axis that controls the position of the first turret TA1 and a control axis that controls the position of the spindle S.

[0042] The first turret TA1 moves, for example, only along the X1 axis. In other words, the first turret TA1 does not move parallel to the rotation axis RA of the main shaft S. The X1 axis is the only control axis for controlling the position of the first turret TA1.

[0043] The spindle S is connected to a chuck that grips a workpiece and rotates around a rotation axis RA. That is, the spindle S rotates the workpiece. For example, in the first system, the spindle S moves only along the Z1 axis. That is, in the first system, the control axis that controls the position of the spindle S is the Z1 axis.

[0044] The second system includes a second turret TA2. In other words, the second system includes a control axis that controls the position of the second turret TA2. The second system may machine a workpiece that is rotated by a spindle S. In this case, the movement of the spindle S in the Z1-axis direction is controlled by a first machining program for controlling the first system.

[0045] The second turret TA2 moves, for example, along the X2 and Z2 axes, i.e., the control axes for controlling the position of the second turret TA2 are the X2 and Z2 axes.

[0046] The dependency is a master-slave relationship between multiple control axes. In controlling the first system, the numerical controller 2 moves the spindle S along the Z1 axis, for example. In controlling the second system, the numerical controller 2 moves the second turret TA2 along the Z2 axis, for example.

[0047] When the numerical control device 2 moves the second turret TA2 along the Z2 axis based on the second machining program, it moves the second turret TA2 based on the position of the spindle S. For example, when the spindle S moves by ΔZ along the Z1 axis under the control of the first system, the numerical control device 2 moves the second turret TA2 along the Z2 axis to a position indicated by the value obtained by adding ΔZ to the value commanded by the second machining program.

[0048] That is, the numerical control device 2 controls the Z2 axis in accordance with the position of the Z1 axis. In other words, the Z1 axis that moves the spindle S and the Z2 axis that moves the second turret TA2 have a master-slave relationship with each other.

[0049] In the example shown in Figure 3, the first control axis is the Z1 axis, which is the control axis of the spindle S. The second control axis is the Z2 axis, which is the control axis of the second turret TA2. The relationship information is information indicating that the Z1 axis, which is the control axis of the spindle S, and the Z2 axis, which is the control axis of the second turret TA2, are in a master-slave relationship. The relationship information may be a mathematical formula indicating that the position of the second turret TA2 on the Z2 axis can be determined by adding the position of the spindle S on the Z1 axis and the distance between the spindle S and the second turret TA2. Now, let's return to the explanation of Figure 2.

[0050] The status information acquisition unit 212 acquires status information indicating the status of the processing machine 1. The status information indicating the status of the processing machine 1 is, for example, temperature information indicating the temperature of the processing machine 1. The temperature of the processing machine 1 may be the temperature of each of the structures that make up the processing machine 1. The structures that make up the processing machine 1 are, for example, the bed, ball screw, turret, headstock, and spindle S.

[0051] The status information acquisition unit 212 acquires temperature information from, for example, temperature sensors provided in various parts of the processing machine 1. The status information acquisition unit 212 may acquire temperature information indicating the temperature in a factory where the processing machine 1 is installed. In this case, the temperature in the factory is regarded as the temperature of the processing machine 1.

[0052] The correction information acquisition unit 213 acquires first correction information indicating the amount of correction for the position of the first control axis based on the status information acquired by the status information acquisition unit 212. The first correction information and second correction information (described later) may be information indicating the amount of correction for correcting an error caused by thermal displacement of the processing machine 1. In this case, the error is, for example, the difference between the position of a structure before the thermal displacement occurs and the position of the structure after the thermal displacement occurs. The structure is a structure that constitutes the processing machine 1, such as the bed, ball screw, turret, headstock, and spindle S.

[0053] 4 is a diagram for explaining the error. A first tool TO1 is attached to a first turret TA1. A workpiece W is attached to a spindle S. A second tool TO2 is attached to a second turret TA2.

[0054] position P11 is the position of the cutting edge of the first tool TO1 before the thermal displacement occurs. 12 is the position of the cutting edge of the first tool TO1 after the thermal displacement occurs. 11 From position P 12 The arrow pointing to is a vector indicating the error in the position of the first tool TO1. 11 From position P 12 The arrow pointing to is a vector indicating the error in the position of the first turret TA1. The length of this vector is Δ1. In other words, the occurrence of thermal displacement causes an error of Δ1 in the position of the cutting edge of the first tool TO1.

[0055] position P S1 is the position of the end face of the workpiece W before thermal displacement occurs. Position P S2 is the position of the end face of the workpiece W after thermal displacement occurs. Position P S1 From position P S2 The arrow pointing to is a vector indicating the error in the position of the end face of the workpiece W. In other words, the position P S1 From position P S2 The arrow pointing towards is a vector indicating the error in the position of the spindle S. The length of this vector is ΔS. In other words, the occurrence of thermal displacement causes an error of ΔS in the position of the end face of the workpiece W.

[0056] position P 21 is the position of the cutting edge of the second tool TO2 before the thermal displacement occurs. 22 is the position of the cutting edge of the second tool TO2 after the thermal displacement occurs. 21 From position P 22 The arrow pointing to is a vector indicating the error in the position of the second tool TO2. 21 From position P 22 The arrow pointing to is a vector indicating the error in the position of the second turret TA2. The length of this vector is Δ2. In other words, the occurrence of thermal displacement causes an error of Δ2 in the position of the cutting edge of the second tool TO2.

[0057] The correction information acquisition unit 213 acquires the correction amount for each control axis, for example, using a table or a formula in which status information and error amounts are associated. When a formula is used, the correction information acquisition unit 213 may calculate the correction amount for each control axis from the status information and the formula when processing is executed. A table or a formula in which status information and error amounts are associated is provided for each combination of structures that make up the processing machine 1, for example.

[0058] FIG. 5 is an example of a table listing the positional relationship error between the spindle S and the first tool TO1. For example, when the temperature of the machine tool 1 is T1 [°C], an error of E1 [mm] occurs along the Z1 axis in the positional relationship between the spindle S and the first tool TO1. In other words, when the temperature of the machine tool 1 is T1 [°C], the spindle S and the first tool TO1 displace along the Z1 axis, and the difference between the displacement of the spindle S and the displacement of the first tool TO1 is E1 [mm]. Furthermore, when the temperature of the machine tool 1 is T2 [°C], an error of E2 [mm] occurs along the Z1 axis in the positional relationship between the spindle S and the first tool TO1. In other words, when the temperature of the machine tool 1 is T2 [°C], the spindle S and the first tool TO1 displace along the Z1 axis, and the difference between the displacement of the spindle S and the displacement of the first tool TO1 is E2 [mm].

[0059] The table or formula may be created, for example, based on data indicating the relationship between temperature and error caused by thermal displacement, which is obtained in advance through an experiment. The formula may be created, for example, by a machine learning technique. The temperatures may be those at two or more locations on the processing machine 1. The temperatures may be those at two or more points on the time axis. That is, the table may be a multidimensional table indicating the relationship between multiple pieces of status information and the amount of error. That is, the formula may be a multivariable function with multiple pieces of status information as variables. The table or formula may be stored, for example, in a memory unit (not shown). Here, acquisition of the first correction information will be described using FIG. 4.

[0060] Vector P S1 P 11 indicates the positional relationship between the end face of the workpiece W and the cutting edge of the first tool TO1 before the thermal displacement occurs. 11and the position P of the end face of the workpiece W S1 are the positions P 12 and position P S2 If the displacement is Δ1-ΔS=+Z d1 Therefore, in order to maintain the positional relationship between the end face of the workpiece W and the cutting edge of the first tool TO1 before the thermal displacement occurs, the spindle S is rotated along the Z1 axis to +Z d1 That is, the compensation information acquisition unit 213 determines the compensation amount of the Z1 axis that controls the spindle S by +Z d1 In other words, the first correction information is determined as +Z d1 is.

[0061] Correction information calculation unit 214 calculates second correction information indicating the amount of correction for the position of the second control axis, based on the relationship information acquired by relationship information acquisition unit 211 and the first correction information acquired by correction information acquisition unit 213. Here, calculation of the second correction information will be described again with reference to FIG. 4 .

[0062] Vector P S1 P 21 indicates the positional relationship between the end face of the workpiece W and the cutting edge of the second tool TO2 before the thermal displacement occurs. As described above, the position P of the spindle S is changed by the thermal displacement. S1 is position P S2 In addition, the cutting edge of the second tool TO2 moves to the position P 21 is position P 22 If the position of the spindle S is +Z indicated by the first correction information, d1 If only the position P S2 and position P 22 The difference is ΔS-Δ2=-Z d2 Therefore, in order to maintain the positional relationship between the end face of the workpiece W and the cutting edge of the second tool TO2 before the thermal displacement occurs, the second turret TA2 is moved along the Z2 axis to -Z d2 That is, based on a table in which the error in the positional relationship between the second tool TO2 and the spindle S is recorded, the compensation information acquisition unit 213 determines the compensation amount of the Z2 axis, which is the second control axis, when the position of the spindle S is not compensated, by -Z d2is decided.

[0063] However, the position of the spindle S is +Z indicated by the first correction information. d1 Therefore, in order to maintain the positional relationship between the end face of the workpiece W and the cutting edge of the second tool TO2 before the thermal displacement occurs, the second turret TA2 is moved along the Z2 axis by -Z d2 +Z d1 That is, the correction information calculation unit 214 calculates the relationship information indicating that the Z1 axis and the Z2 axis are in a master-slave relationship, and the +Z d1 -Z, which is second correction information indicating the correction amount of the position of the second control axis, based on d2 +Z d1 Calculate.

[0064] The correction unit 215 corrects the position of the second control axis based on the second correction information calculated by the correction information calculation unit 214. The correction unit 215 corrects the position of the second control axis by operating the second control axis. The correction information calculation unit 214 calculates -Z as the second control information. d2 +Z d1 is calculated, the correction unit 215 moves the second turret TA2 along the Z2 axis to -Z d2 +Z d1 This allows the numerical control device 2 to correct the error that occurs in the processing machine 1.

[0065] The correction unit 215 may correct the position of the second control axis by rewriting the coordinate value of the second control axis. For example, the correction information calculation unit 214 may calculate -Z d2 +Z d1 is calculated, the Z2 axis reaches the stroke limit, so the second turret TA2 is moved along the Z2 axis to -Z d2 +Z d1 In this case, the correction unit 215 subtracts the Z2 axis coordinate value from the Z3 axis coordinate value. d2 +Z d1 In this way, the numerical control device 2 can correct the error that occurs in the processing machine 1.

[0066] 6 is a flowchart showing an example of processing executed by the numerical control device 2. In the numerical control device 2, first, the relationship information acquisition unit 211 acquires relationship information indicating the dependency relationship between the first control axis and the second control axis (step S1).

[0067] Next, the status information acquisition unit 212 acquires status information indicating the status of the processing machine 1 (step S2). Next, the correction information acquisition unit 213 acquires first correction information indicating the amount of correction for the position of the first control axis based on the status information acquired by the status information acquisition unit 212 (step S3).

[0068] Next, the correction information calculation unit 214 calculates second correction information indicating the amount of correction for the position of the second control axis based on the relationship information acquired by the relationship information acquisition unit 211 and the first correction information acquired by the correction information acquisition unit 213 (step S4).

[0069] Next, the correction unit 215 corrects the position of the second control axis based on the second correction information calculated by the correction information calculation unit 214 (step S5), and the processing in the numerical control device 2 ends. After or in parallel with the error correction, the numerical control device 2 controls the processing machine 1 based on the machining program to perform machining of the workpiece W.

[0070] In the above-described embodiment, the first compensation information and the second compensation information are information indicating compensation amounts for compensating for errors caused by thermal displacement of the processing machine 1. However, the first compensation information and the second compensation information may be information indicating compensation amounts for compensating for mechanical errors of the processing machine 1. Mechanical errors are errors that occur when each structure moves along a control axis or when each structure rotates around the rotation axis RA. In other words, mechanical errors are the difference between the position indicated by a command and the actual position of a structure when the structure operates based on the command of a machining program.

[0071] 7 is a diagram for explaining a machine error. A processing machine 1 in which a machine error occurs is, for example, a multi-tasking machine 11 having a tilting head.

[0072] The multi-tasking machine 11 has, for example, a first system and a second system. The first system includes a first tilt head AH1 and a spindle S.

[0073] The first tilt head AH1 moves along the X1 axis, for example, and rotates around the C1 axis. That is, the control axes for controlling the first tilt head AH1 are the X1 axis and the C1 axis.

[0074] The spindle S is connected to a chuck that grips the workpiece W and rotates around a rotation axis RA. That is, the spindle S rotates the workpiece W. For example, in the first system, the spindle S moves only along the Z1 axis. That is, in the first system, the only control axis that controls the position of the spindle S is the Z1 axis.

[0075] The second system includes a second tilt head AH2. The second system may machine a workpiece that is rotated by a spindle S. In this case, the movement of the spindle S in the Z1-axis direction is controlled by a first machining program for controlling the first system.

[0076] The second tilt head AH2 moves, for example, along the X2 and Z2 axes, i.e., the control axes for controlling the position of the second tilt head AH2 are the X2 and Z2 axes.

[0077] In the example shown in FIG. 7, the numerical control device 2 moves the spindle S along the Z1 axis and rotates the first tilt head AH1 around the C1 axis in the control of the first system.

[0078] When the numerical controller 2 moves the second tilt head AH2 along the Z2 axis under control of the second system, it moves the second tilt head AH2 based on the position of the spindle S. Therefore, when the spindle S is moving under control of the first system, the numerical controller 2 must move the second tilt head AH2 based on the position of the moved spindle S. In other words, the spindle S and the second tilt head AH2 have a master-slave relationship. In the example shown in FIG. 7 , the Z1 axis, which is the control axis of the spindle S, corresponds to the first control axis. The Z2 axis, which is the control axis of the second tilt head AH2, corresponds to the second control axis.

[0079] The relationship information acquisition unit 211 acquires relationship information indicating the dependency between the spindle S and the second tilt head AH2.

[0080] The status information acquisition unit 212 acquires status information indicating the status of the processing machine 1. The status information indicating the status of the processing machine 1 is, for example, angle information indicating the tilt angle of the first tilt head AH1.

[0081] The state information acquisition unit 212 acquires angle information from, for example, an encoder attached to the rotation axis RA of the first tilt head AH1.

[0082] The correction information acquisition unit 213 acquires first correction information indicating the amount of correction for the position of the spindle S based on the state information acquired by the state information acquisition unit 212 .

[0083] When the first tilt head AH1 is rotated around the C1 axis, the ideal position of the tip of the tool T can be determined from the rotation angle of the first tilt head AH1 around the C1 axis and the distance between the center of the C1 axis and the tip of the tool T. However, if a mechanical error occurs during rotation of the first tilt head AH1, the tip position of the tool T will deviate from the ideal position by, for example, +ΔZ along the Z1 axis. In this case, the position of the spindle S must be corrected by +ΔZ along the Z1 axis. That is, the correction information acquisition unit 213 acquires +ΔZ as the first correction information.

[0084] The correction information acquisition unit 213 acquires the first correction information using, for example, a table in which state information and the amount of error are associated with each other.

[0085] 8 shows an example of a table for obtaining the mechanical error of the first tilt head AH1. For example, when the first tilt head AH1 rotates by A1°, the position of the tip of the tool T deviates from the ideal position along the Z1 axis by E11 [mm]. When the first tilt head AH1 rotates by A2°, the position of the tip of the tool T deviates from the ideal position along the Z1 axis by E12 [mm].

[0086] The table may be created, for example, based on data indicating the relationship between the rotation angle and the mechanical error of the first tilt head AH1, which data is obtained in advance through an experiment, and may be stored in a storage unit (not shown).

[0087] The correction information calculation unit 214 calculates second correction information indicating the amount of correction for the position of the second control axis, based on the relationship information acquired by the relationship information acquisition unit 211 and the first correction information acquired by the correction information acquisition unit 213. Here, the calculation of the second correction information will be described with reference to FIG. 7 .

[0088] When the position of the tip of the tool T deviates by +ΔZ along the Z1 axis due to a mechanical error, the spindle S needs to be moved by +ΔZ along the Z1 axis in order to correct the mechanical error. In other words, the correction information acquisition unit 213 acquires +ΔZ as the first correction information.

[0089] Furthermore, when the correction information acquisition unit 213 acquires +ΔZ as the first correction information, the second tilt head AH2 needs to be moved by +ΔZ along the Z2 axis in order to maintain the positional relationship between the main axis S and the second tilt head AH2 at the positional relationship before the correction of the main axis S. In other words, the correction information calculation unit 214 calculates +ΔZ as the second correction information.

[0090] The correction unit 215 corrects the position of the second control axis based on the second correction information calculated by the correction information calculation unit 214. When the correction information calculation unit 214 calculates +ΔZ as the second correction information, the correction unit 215 moves the second tilt head AH2 by +ΔZ along the Z2 axis. This allows the numerical control device 2 to correct the error occurring in the processing machine 1.

[0091] The correction unit 215 may correct the position of the second control axis by rewriting the coordinate value of the second control axis. Even if the correction information calculation unit 214 calculates +ΔZ as the second correction information, there may be cases where the second tilt head AH2 cannot be moved by +ΔZ along the Z2 axis because the Z2 axis controlling the second tilt head AH2 reaches its stroke limit. In this case, the correction unit 215 subtracts ΔZ from the coordinate value of the Z2 axis. This allows the numerical control device 2 to correct the error occurring in the machining machine 1.

[0092] As described above, the machining center 1 has a first control axis included in a first system and a second control axis included in a second system, and is equipped with: a relationship information acquisition unit 211 that acquires relationship information indicating the dependency between the first control axis and the second control axis; a status information acquisition unit 212 that acquires status information indicating the status of the machining center 1; a correction information acquisition unit 213 that acquires first correction information indicating the amount of correction for the position of the first control axis based on the status information acquired by the status information acquisition unit 212; a correction information calculation unit 214 that calculates second correction information indicating the amount of correction for the position of the second control axis based on the relationship information acquired by the relationship information acquisition unit 211 and the first correction information acquired by the correction information acquisition unit 213; and a correction unit 215 that corrects the position of the second control axis based on the second correction information calculated by the correction information calculation unit 214.

[0093] Therefore, the numerical control device 2 can appropriately correct errors in the processing machine 1 in which there is a dependency between multiple systems.

[0094] Furthermore, the correction unit 215 operates the second control axis to correct the position of the second control axis, thereby enabling the numerical control device 2 to effectively correct errors occurring in the processing machine 1.

[0095] Alternatively, the correction unit 215 corrects the position of the second control axis by rewriting the coordinate value of the second control axis. Therefore, the numerical control device 2 can correct the error generated in the processing machine 1 even when the second control axis has reached the stroke limit.

[0096] The first compensation information and the second compensation information are information indicating the amount of compensation for compensating for errors caused by thermal displacement of the processing machine 1. Therefore, the numerical control device 2 can effectively compensate for errors caused by thermal displacement in the processing machine 1.

[0097] Alternatively, the first compensation information and the second compensation information are information indicating the compensation amount for compensating for the mechanical error of the processing machine 1. Therefore, the numerical control device 2 can effectively compensate for the mechanical error occurring in the processing machine 1.

[0098] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible to these embodiments without departing from the spirit of the present disclosure, or within the spirit of the present disclosure derived from the claims and their equivalents. These embodiments can also be implemented in combination. For example, a third control axis may be added to the examples, and a dependency relationship may exist between the first control axis, the second control axis, and the third control axis. Furthermore, a third control axis and a fourth control axis may be added to the examples, and two sets of dependency relationships may exist: a dependency relationship between the first control axis and the second control axis, and a dependency relationship between the third control axis and the fourth control axis.

[0099] The following are supplementary notes related to embodiments of the present disclosure. Supplementary note [1] A numerical control device for a machining center having a first control axis included in a first system and a second control axis included in a second system, the numerical control device comprising: a relationship information acquisition unit that acquires relationship information indicating a dependency relationship between the first control axis and the second control axis; a state information acquisition unit that acquires state information indicating a state of the machining center; a correction information acquisition unit that acquires first correction information indicating a correction amount for a position of the first control axis based on the state information acquired by the state information acquisition unit; a correction information calculation unit that calculates second correction information indicating a correction amount for the position of the second control axis based on the relationship information acquired by the relationship information acquisition unit and the first correction information acquired by the correction information acquisition unit; and a correction unit that corrects the position of the second control axis based on the second correction information calculated by the correction information calculation unit. Supplementary note [2] The numerical control device according to Supplementary note [1], wherein the correction unit corrects the position of the second control axis by operating the second control axis. Supplementary Note [3] The numerical control device according to Supplementary Note [1], wherein the correction unit corrects the position of the second control axis by rewriting a coordinate value of the second control axis.Supplementary Note [4] The numerical control device according to any of Supplements [1] to [3], wherein the first correction information and the second correction information are information indicating a correction amount for correcting an error caused by thermal displacement of the processing machine.Supplementary Note [5] The numerical control device according to any of Supplements [1] to [3], wherein the first correction information and the second correction information are information indicating a correction amount for correcting a mechanical error of the processing machine.Supplementary Note [6] A computer-readable storage medium storing instructions that cause a computer to execute the following in a machining center having a first control axis included in a first system and a second control axis included in a second system: acquiring relationship information that indicates a dependency relationship between the first control axis and the second control axis; acquiring status information that indicates a status of the machining center; acquiring first compensation information that indicates a compensation amount for a position of the first control axis based on the acquired status information; calculating second compensation information that indicates a compensation amount for the position of the second control axis based on the acquired relationship information and the acquired first compensation information; and compensating the position of the second control axis based on the calculated second compensation information.

[0100] REFERENCE SIGNS LIST 1 Machining machine 11 Multi-tasking machine 2 Numerical control device 201 Hardware processor 202 Bus 203 ROM 204 RAM 205 Non-volatile memory 206 Interface 207 Axis control circuit 208 Spindle control circuit 209 PLC 210 I / O unit 211 Related information acquisition unit 212 Status information acquisition unit 213 Correction information acquisition unit 214 Correction information calculation unit 215 Correction unit 3 Input / output device 4 Servo amplifier 5 Servo motor 6 Spindle amplifier 7 Spindle motor 8 Auxiliary equipment

Claims

1. A numerical control device for a machining center having a first control axis included in a first system and a second control axis included in a second system, comprising: a relationship information acquisition unit that acquires relationship information indicating a dependency between the first control axis and the second control axis; a status information acquisition unit that acquires status information indicating a status of the machining center; a correction information acquisition unit that acquires first correction information indicating a correction amount for the position of the first control axis based on the status information acquired by the status information acquisition unit; a correction information calculation unit that calculates second correction information indicating a correction amount for the position of the second control axis based on the relationship information acquired by the relationship information acquisition unit and the first correction information acquired by the correction information acquisition unit; and a correction unit that corrects the position of the second control axis based on the second correction information calculated by the correction information calculation unit.

2. The numerical control device according to claim 1, wherein the correction unit corrects the position of the second control axis by operating the second control axis.

3. The numerical control device according to claim 1, wherein the correction unit corrects the position of the second control axis by rewriting the coordinate value of the second control axis.

4. A numerical control device according to any one of claims 1 to 3, wherein the first correction information and the second correction information are information indicating a correction amount for correcting an error caused by thermal displacement of the machining machine.

5. A numerical control device according to any one of claims 1 to 3, wherein the first compensation information and the second compensation information are information indicating a compensation amount for compensating for a mechanical error of the processing machine.

6. A computer-readable storage medium storing instructions that cause a computer to execute the following in a machining center having a first control axis included in a first system and a second control axis included in a second system: acquiring relationship information indicating a dependency between the first control axis and the second control axis; acquiring status information indicating a status of the machining center; acquiring first compensation information indicating an amount of compensation for the position of the first control axis based on the acquired status information; calculating second compensation information indicating an amount of compensation for the position of the second control axis based on the acquired relationship information and the acquired first compensation information; and compensating the position of the second control axis based on the calculated second compensation information.