JP2012056005A - Method and apparatus for setting parameter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily perform setup of a parameter for controlling a feed shaft of a machining tool in a short time.SOLUTION: A parameter setup apparatus 56 performs the setup of the parameter for controlling the feed shaft of the machining tool 10. The parameter setup apparatus includes: a determination part 84 for determining whether the inertia of a load object to be loaded on the machining tool is stored in a storage part 82 of a processing control system connected to the machining tool; a calculation part 76 for measuring the inertia of the load object and storing it when the inertia is not stored in the storage part, and also when the inertia is stored in the storage part, reading the stored inertia, and based on the measured or read inertia of the load object, calculating the parameter for controlling the feed shaft of the machining tool; and a setup part 86 for setting the control parameter calculated by the calculation part with respect to the feed shaft of the machining tool.

Description

  The present invention relates to a parameter setting method for setting a control parameter of a feed axis of a machine tool and a parameter setting device for implementing the method.

  The machine tool includes one or more linear feed axes and / or rotary feed axes (hereinafter, these linear feed axes and rotary feed axes are simply referred to as “feed axes”) for driving these feed axes. These motors are controlled by a numerical controller. In machine tools, different tools are attached according to the machining content of the workpiece, and jigs for attaching the workpiece to the machine tool are also different depending on the workpiece.

  In a system including such a machine tool, it is necessary to set control parameters such as an acceleration / deceleration time constant, a reverse correction value, various gains, and a filter on the feed axis. In order to set these control parameters, it is necessary to acquire the inertia, the viscous friction coefficient, and the Coulomb friction force acting on each feed shaft of the machine tool. In Patent Document 1, such inertia and viscous friction are obtained. The acquisition method of the coefficient and Coulomb friction force is disclosed. Patent Document 2 discloses a numerical control device in which parameters are changed according to conditions.

JP-A-3-290706 JP 2006-346760 A

  However, when a workpiece placed on a certain machine tool is machined by another machine tool, it is necessary to set the control parameters by acquiring the inertia, the viscous friction coefficient, and the Coulomb friction force again. In addition, the processing is complicated. Similarly, in a machine tool having a plurality of feed axes, after obtaining inertia, viscous friction coefficient, and Coulomb friction force for a feed axis and setting control parameters, the same applies to other feed axes. It is necessary to acquire inertia, viscous friction coefficient, and Coulomb friction force, and the same problem occurs in a single machine tool.

  The present invention has been made in view of such circumstances, and when a jig or workpiece placed on a certain machine tool is placed on another machine tool for processing, or on a certain feed shaft of the machine tool. Even if the control parameters are set for other feed axes after setting the control parameters, the parameter setting method and method for setting the control parameters can be performed easily and in a short time. An object is to provide a parameter setting device.

  In order to achieve the above-described object, according to the first invention, in the parameter setting method for setting the control parameter of the feed axis of the machine tool, is the inertia of the load loaded on the machine tool stored in the storage unit? If the inertia is not stored in the storage unit, the inertia of the load is measured and stored. If the inertia is stored in the storage unit, the inertia is stored. Reading inertia, calculating control parameters of the feed axis of the machine tool based on measured or read inertia of the load, and setting the calculated control parameters for the feed axis of the machine tool A characteristic parameter setting method is provided.

  According to the second invention, in the parameter setting method for setting a control parameter for one feed axis of a plurality of feed axes of a machine tool, the inertia of a load placed on the machine tool is stored for the one feed axis. When the inertia is not stored in the storage unit, the inertia of the load is measured and stored, and the inertia is stored in the storage unit The stored inertia is read, the control parameter of the one feed axis of the machine tool is calculated based on the measured or read inertia of the load, and the calculated control parameter is calculated as the one of the machine tool. A parameter setting method is provided which is characterized by setting for one feed axis.

  According to a third aspect, in the first or second aspect, the storage unit stores a friction coefficient of coulomb friction and viscous friction of the feed shaft, and the control parameter includes the friction coefficient, the inertia, Is calculated based on

  According to a fourth aspect, in the third aspect, the control parameter that changes according to the friction coefficient and the inertia, and the control parameter that is set to a constant value for each range of the friction coefficient and the inertia value. And are calculated.

  According to a fifth aspect, in the third aspect, the storage unit stores a relationship between a motor temperature of a motor that operates the feed shaft of the machine tool and a torque constant of the motor, and the control unit The parameter is calculated based on the relationship, the friction coefficient, and the inertia.

  According to the sixth aspect of the invention, in the parameter setting device for setting the control parameter of the feed axis of the machine tool, the inertia of the load placed on the machine tool is stored in the storage unit of the machining management system connected to the machine tool. A determination unit that determines whether or not the load has been stored, and when the inertia is not stored in the storage unit, the inertia of the load is measured and stored, and the inertia is stored in the storage unit Includes reading a stored inertia, calculating a control parameter for the feed axis of the machine tool based on the measured or read inertia of the load, and a control parameter calculated by the calculation unit. And a setting unit configured to set the feed axis of the machine tool.

  According to the seventh aspect, in the parameter setting device for setting the control parameter of one of the plurality of feed axes of the machine tool, the inertia of the load to be placed on the machine tool for the one feed axis is provided. A determination unit that determines whether or not the data is stored in a storage unit, and if the inertia is not stored in the storage unit, the inertia of the load is measured and stored, and the inertia is stored in the storage unit If the stored inertia is read, the control unit calculates the control parameter of the one feed axis of the machine tool based on the measured or read inertia of the load, and the calculation unit A parameter setting device comprising: a setting unit configured to set the calculated control parameter for the one feed axis of the machine tool. It is subjected.

  According to an eighth invention, in the sixth or seventh invention, the storage unit stores a friction coefficient of Coulomb friction and viscous friction of the feed shaft, and the control parameter includes the friction coefficient, the inertia, Is calculated based on

  According to a ninth aspect, in the eighth aspect, the control parameter that changes according to the friction coefficient and the inertia, and the control parameter that is set to a constant value for each range of the friction coefficient and the inertia value. And are calculated.

  According to a tenth aspect, in the sixth or seventh aspect, the storage unit stores a relationship between a motor temperature of a motor that operates the feed shaft of the machine tool and a torque constant of the motor. The control parameter is calculated based on the relationship, the friction coefficient, and the inertia.

  In the first or sixth invention, even when a workpiece placed on a certain machine tool is processed by another machine tool, the inertia measured by the certain machine tool can be used by another machine tool. . Accordingly, it is possible to reduce the number of times of inertia measurement and calculation, and as a result, the control parameters can be set easily and in a short time.

  In the second or seventh invention, even if it is necessary to set a control parameter for another feed axis after setting a parameter for a feed axis of a machine tool, Inertia measured on the axis can be used on other feed axes. Accordingly, it is possible to reduce the number of times of inertia measurement and calculation, and as a result, the control parameters can be set easily and in a short time.

  In the third or eighth invention, since both Coulomb friction and viscous friction are considered, the control parameter can be set more precisely.

  In the fourth or ninth invention, the control parameter setting method is changed according to the characteristics of the control parameter, so that the control parameter can be set more appropriately. The control parameters that change according to the friction coefficient and the inertia are an acceleration / deceleration time constant, a reverse correction value, and the like. Control parameters set to a constant value for each range of values of the friction coefficient and the inertia are various gains, filters, and the like.

  In the fifth or tenth invention, since the control parameter is set in consideration of the motor temperature, the control parameter can be set more precisely.

It is the schematic of the numerical control machine tool of this invention. It is a block diagram of the configuration of an arithmetic control unit that controls the numerically controlled machine tool of the present invention. FIG. 3 is an additional configuration block diagram of an arithmetic control unit shown in FIG. 2. It is a flowchart of the calculation method which calculates a control parameter when a feed axis is a linear motion axis. (A) It is a figure which shows the relationship between an inertia in the case of viscous friction, and a friction coefficient. (B) It is a figure which shows the relationship between an inertia in the case of Coulomb friction, and a friction coefficient. It is a flowchart of the calculation method which calculates a control parameter when a feed axis is a rotation feed axis. It is a flowchart which shows the calculation method which calculates an inertia and a friction coefficient. It is a figure which shows the relationship between a torque constant and motor temperature. It is a flowchart which shows the calculation method which calculates a control parameter. (A) It is a figure which shows the control parameter which changes linearly with respect to an inertia or a friction coefficient. (B) It is a figure which shows the control parameter which changes in a curve shape with respect to an inertia or a friction coefficient. (C) It is a figure which shows the control parameter which changes in a step shape with respect to an inertia or a friction coefficient.

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following drawings, the same members are denoted by the same reference numerals. In order to facilitate understanding, the scales of these drawings are appropriately changed.
FIG. 1 is a schematic view of a numerically controlled machine tool of the present invention. In FIG. 1, a numerically controlled machine tool 10 is a so-called horizontal machining center and includes a bed 12 installed on a floor surface of a factory or the like. A Z-axis guide rail 28 extends in the horizontal Z-axis direction (left-right direction in FIG. 1) on the upper surface of the bed 12, and a workpiece W is placed on the Z-axis guide rail 28 via a workpiece jig G. A table 14 for fixing is slidably attached. FIG. 1 shows an example in which an NC rotary table that can be rotationally fed in the B-axis direction is fixed on a table 14 and a workpiece W is loaded thereon, but the table 14 is not provided with an NC rotary table interposed. The workpiece W may be loaded directly on the top.

  An X-axis guide rail 36 is further extended on the upper surface of the bed 12 in a direction perpendicular to the Z-axis and in the horizontal X-axis direction (perpendicular to the paper surface of FIG. 1). A column 16 is slidably attached. A Y-axis guide rail 34 extends in the Y-axis direction (vertical direction in FIG. 1) orthogonal to the X-axis and the Z-axis on the front surface facing the workpiece W in the column 16. A spindle head 18 that rotatably supports the spindle 20 is slidably attached.

  A Z-axis feed screw 24 extends in the Z-axis direction below the table 14 in the bed 12, and a nut 26 that is screwed to the Z-axis feed screw 24 is fixed to the lower surface of the table 14. A Z-axis feed servo motor Mz is connected to one end of the Z-axis feed screw 24, and the table 14 is attached to the Z-axis guide rail 28 by driving the Z-axis feed servo motor Mz to rotate the Z-axis feed screw 24. Move along. Similarly, an X-axis feed screw (not shown) extends in the X-axis direction below the column 16 in the bed 12, and a nut (threaded to the X-axis feed screw is engaged with the lower surface of the column 16. (Not shown) is fixed.

  An X-axis feed servo motor Mx is connected to one end of the X-axis feed screw, and the column 16 is connected to the X-axis guide rail 36 by driving the X-axis feed servo motor Mx and rotating the X-axis feed screw. Move along. Further, a Y-axis feed screw 32 extends in the Y-axis direction in the column 16, and a nut 30 that is screwed to the Y-axis feed screw 32 is fixed to the back surface of the spindle head 18. A Y-axis feed servo motor My is connected to the upper end of the Y-axis feed screw 32. By driving the Y-axis feed servo motor My and rotating the Y-axis feed screw 32, the spindle head 18 is moved to the Y-axis guide rail 34. Move along.

  A tool 22, such as an end mill, is attached to the tip of the main shaft 20. While the tool 22 is rotated, the column 16, the spindle head 18, and the table 14 are moved in the X-axis, Y-axis, and Z-axis directions, respectively, thereby cutting the workpiece W fixed to the table 14 into a desired shape. When the NC rotary table is fixed, the numerically controlled machine tool 10 can be said to be a 4-axis numerically controlled machine tool having a B axis.

  The numerically controlled machine tool 10 is a numerical controller that controls the X axis, Y axis, and Z axis feed servo motors Mx, My, and Mz that move the column 16, spindle head 18, and table 14 in the X axis, Y axis, and Z axis directions. Part 40 is provided. When an NC rotary table is provided, a B-axis feed servo motor (not shown) is provided.

  The numerical control unit 40 reads the NC program 42 and interprets the program read / interpretation unit 44, the interpreted program storage unit 46 that temporarily stores the interpreted program, and the interpreted program storage unit 46 appropriately pulling out the program. A program execution command unit 48 that issues execution program data, and a distribution that generates position command values, speed command values, and acceleration command values for each of the X, Y, and Z axes based on the execution program data from the program execution command unit 48 A servo control unit 52 that issues a torque command value or a current command value to the feed shaft motor drive unit 54 based on a position command value, a speed command value, an acceleration command value, and a feedback signal described later, from the control unit 50 and the distribution control unit 50 Contains. Similarly for the B axis, the distribution control unit 50 issues a position command value, an angular velocity command value, and an angular acceleration command value for the B axis.

  The feed shaft motor drive unit 54 outputs current based on the torque command value or current command value from the servo control unit 52 to drive the feed shaft motors Mx, My, Mz of the X axis, Y axis, and Z axis. . Furthermore, in the present embodiment, an arithmetic control unit 56 that corrects a torque command value or a current command value from the servo control unit 52 to the feed shaft motor drive unit 54 is provided.

  FIG. 2 is a block diagram showing the configuration of an arithmetic control unit for controlling the numerically controlled machine tool of the present invention. In the embodiment of FIG. 2, the calculation control unit 56 includes a calculation unit 76 including a torque calculation unit 96 and a parameter calculation unit 98. In FIG. 2, the components corresponding to FIG. 1 are indicated by the same reference numerals. The calculation unit 76 performs various calculation processes described later.

  The servo control unit 52 subtracts the position feedback signal of the position detector SP such as a digital linear scale attached to the table 14 from the position command value from the distribution control unit 50 based on the output from the subtractor 58 and the subtractor 58. A position control unit 60 that controls the position, a subtractor 62 that subtracts a speed feedback signal from the pulse coder PC provided in the feed shaft motor M from a speed command output from the position control unit 60, and a speed based on the output of the subtractor 62. A speed control unit 64 for control is included.

  On the other hand, the position command value, the speed command value, and the acceleration command value from the distribution control unit 50 are also sent to the speed feedforward control unit 90 and the acceleration feedforward control unit 92 every moment. The speed feedforward control unit 90 and the acceleration feedforward control unit 92 generate a speed feedforward value and an acceleration feedforward value based on the position command value and the like from the distribution control unit 50. The acceleration feedforward value and the output from the speed control unit 64 are added by the adder 94 and supplied to the feed shaft motor drive unit 54.

  Further, the feed shaft motor M is provided with a current detector 72 that detects a current flowing through the feed shaft motor M and a temperature sensor 74 that detects the temperature of the feed shaft motor M. The current value detected by the current detector 72 and the temperature detected by the temperature sensor 74 are output to the torque calculator 96, and the torque calculator 96 calculates the torque acting on the feed shaft motor M. Further, the parameter calculation unit 98 calculates a control parameter based on the torque calculated by the torque calculation unit 96 and the speed feedback signal from the pulse coder PC. The calculation unit 76 performs other calculation processing such as calculation of inertia and friction coefficient.

  FIG. 3 is an additional configuration block diagram of the arithmetic control unit shown in FIG. The control parameters set by the parameter calculation unit 98 in the calculation unit 76 of the calculation control unit 56 are output to the setting unit 86. Next, the setting unit 86 sets a control parameter for the corresponding feed axis. Therefore, the arithmetic control unit 56 serves as a parameter setting device. The arithmetic unit 76 is connected to a storage unit 82 that is included in a host control device separate from the numerically controlled machine tool 10, for example, the processing management system 80 and includes various data. Alternatively, the storage unit 82 may be built in the arithmetic control unit 56 of the numerically controlled machine tool 10.

  The storage unit 82 stores the inertia of the load loaded on the numerically controlled machine tool 10. The inertia means the inertial mass of the load when the feed shaft is a linear feed shaft, and the inertia of the load when the feed shaft is a rotary feed shaft (see arrow B in FIG. 1). Mean moment.

  The load is a general term for the workpiece W, the tool 22, the workpiece jig G, and the like, and the workpiece jig G may not be included in some cases. The storage unit 82 may store inertia for each of the workpiece W, the tool 22, and the workpiece jig G, or may store one inertia for the entire load. The inertia of the load is stored for each of the X axis, the Y axis, the Z axis, and the rotation B axis of the numerically controlled machine tool 10. Further, the inertia of the load is similarly stored in the storage unit 82 for a plurality of machine tools other than the numerically controlled machine tool 10 shown in FIG. The storage unit 82 also stores the relationship between the mass of the load and the friction coefficient, and the relationship between the inertia or the friction coefficient and the control parameter for each machine tool and each feed axis of the machine tool.

  The determination unit 84 determines whether the inertia of the load placed on the numerically controlled machine tool 10 is stored in the storage unit 82. Further, the determination unit 84 can also determine whether or not the inertia of the load placed on the numerical control machine tool 10 for one feed axis of the numerical control machine tool 10 is stored in the storage unit 82.

  FIG. 4 is a flowchart of a calculation method for calculating control parameters when the feed axis is a linear feed axis, for example, the Z axis. Hereinafter, the control parameter calculation method in the present invention will be described with reference to FIG.

  First, the load is mounted on the numerically controlled machine tool 10. In step 110, the storage unit 82 is accessed, and the determination unit 84 determines whether the inertia when the load is placed on the numerically controlled machine tool 10 is stored in the storage unit 82. When the storage unit 82 is incorporated only in the machining management system 80, an operation of connecting the numerically controlled machine tool 10 to the machining management system 80 is included before step 110.

  If such inertia exists, the inertia is read in step 120. On the other hand, if there is no inertia, the inertia and the friction coefficient for the load are measured and calculated in step 190 and stored in the storage unit 82. At this time, the mass of the structure and the mass of the load are separately stored in the storage unit 82 from the obtained inertia. The calculation of the inertia and the friction coefficient will be described later.

  Next, in step 130, the determination unit 84 determines whether or not the friction coefficient when the load is mounted is stored in the storage unit 82. If such a friction coefficient is stored, the friction coefficient is read in step 140. If not stored, the calculation unit 76 uses the relationship between the inertia and the friction coefficient to generate friction from the inertia. A coefficient is calculated (step 150).

  Here, FIG. 5A is a diagram showing the relationship between the inertia and the friction coefficient in the case of viscous friction, and FIG. 5B is a diagram showing the relationship between the inertia and the friction coefficient in the case of Coulomb friction. In steps 140 and 150, the friction coefficients for both viscous friction and Coulomb friction are obtained from these graphs. Note that, instead of the graphs shown in FIGS. 5A and 5B, the friction coefficient may be directly calculated using a relational expression between the inertia and the friction coefficient.

  Thereafter, in step 160, the parameter calculation unit 98 calculates various control parameters based on the inertia and / or the friction coefficient. Finally, the calculated control parameter is set for the corresponding feed axis by the setting unit 86, and the process ends.

  In this way, in the present invention, it is determined whether or not the required inertia and / or friction coefficient is stored in the storage unit 82, and if stored, the inertia and / or friction coefficient is determined. I am trying to use it. Therefore, for example, even when a load placed on another numerically controlled machine tool of the same type is processed by the numerically controlled machine tool 10, the inertia already stored for the other numerically controlled machine tool 10 is stored in the numerically controlled machine tool 10. Can be diverted. For this reason, the number of times of measurement of inertia and the number of calculations can be reduced to the minimum, and as a result, the control parameters can be set easily and in a short time. It should be noted that which machine tool can use data such as inertia of a certain machine tool is predetermined.

  Furthermore, the use of inertia or the like is also possible between one feed axis of the numerically controlled machine tool 10 such as the Z axis and another feed axis of the same numerically controlled machine tool 10 such as the X axis and / or the Y axis. Applicable. Therefore, even in such a case, the number of times of measurement and calculation of inertia and the like can be reduced, and the same effect can be obtained. In this case, the numerically controlled machine tool 10 may include a storage unit 82 that stores inertia and the like. In addition, it is determined in advance which feed axis in the same machine tool can use data such as inertia of a feed axis.

  FIG. 6 is a flowchart of a calculation method for calculating a control parameter when the feed axis is a rotary feed axis, for example, the B axis. When the feed shaft is a rotary feed shaft, the relative position between the center position of the rotary feed shaft and the workpiece mounting position in a certain machine tool 10 is different from similar relative positions in other machine tools. There are times when there is no difference. However, in any of these cases, the flowchart of FIG. 6 can be adopted.

  Since Steps 110 to 160 and Step 190 shown in FIG. 6 are the same as those described above, description thereof will be omitted, and Step 180 will be mainly described. As shown in FIG. 6, when the friction coefficient is not stored in the storage unit 82 in step 130, the process proceeds to step 180. In step 180, the determination unit 84 determines whether or not the mass of the load is stored in the storage unit 82. And when such mass is memorize | stored, it progresses to step 150, and when not memorize | stored, it progresses to step 190. Finally, since the control parameters are calculated in the same manner in step 160, it can be seen that the same effect as described above can be obtained even when the feed axis is a rotary feed axis.

  Here, the inertia and friction coefficient measurement and calculation method shown in step 190 of FIGS. 4 and 6 will be described. FIG. 7 is a flowchart showing a calculation method for calculating the inertia and the friction coefficient.

  In step 210 of FIG. 7, the current detector 72 measures the current value of the feed shaft motor M, the temperature sensor 74 measures the temperature of the feed shaft motor M, and the pulse coder PC measures the speed of the feed shaft motor M. To do. Further, the acceleration of the feed shaft motor M is calculated from the speed of the feed shaft motor M.

  Next, at step 220, the torque constant is obtained from the relationship between the torque constant and the motor temperature shown in FIG. 8, and the torque is obtained from the obtained torque constant and the current value of the feed shaft motor M. Thus, in the present invention, since the torque constant determined according to the motor temperature is used, the torque can be calculated more accurately.

In step 230, inertia and a friction coefficient are calculated from torque (force), speed, and acceleration. When the feed shaft is a linear feed shaft, the following equation (1) is used.

In the equation (1), the unit vector U indicating the force F, the velocity V, the acceleration a, and the velocity direction is known. When the sum of squares of the difference from the force F obtained by substituting the acceleration a, the velocity V and the unit vector U in the velocity direction into the equation (1) is minimized, the determinant represented by the equation (2) is obtained. Therefore, by performing the above measurement n times (n is a natural number), the inertia mass J, the viscous friction coefficient D, and the Coulomb friction C can be calculated from the equation (2).

Further, when the feed shaft is a rotary feed shaft, the following equation (3) is used.

Also in the equation (3), the torque τ, the angular velocity ω, the angular acceleration α, and the coefficient U indicating the velocity direction are known. For this reason, the moment of inertia J, the viscous friction coefficient D, and the Coulomb friction C can be calculated from the determinant represented by Expression (4) by the same method.

  Here, a calculation method for calculating each control parameter from the inertia and / or the friction coefficient in step 160 shown in FIGS. 4 and 6 will be specifically described. FIG. 9 is a flowchart showing a calculation method for calculating the control parameter.

  In step 310 of FIG. 9, it is determined whether or not the control parameter to be obtained is a control parameter that can determine an appropriate value by interpolation. Specifically, when the control parameter is an acceleration / deceleration time constant, a reverse correction value, or the like, these control parameters can be continuously changed according to inertia or a friction coefficient. Accordingly, the acceleration / deceleration time constant, the reverse correction value, and the like are control parameters that can determine appropriate values by linear interpolation or curve interpolation.

  On the other hand, when the control parameters are various gains, filters, etc., these control parameters are determined from an equation or graph of a step function created from a plurality of parameter values whose operation has been confirmed to be stable. Therefore, various gains, filters, and the like are control parameters set to constant values for each range of values of the friction coefficient and the inertia. In other words, various gains, filters, and the like are control parameters that change stepwise with respect to the friction coefficient and / or inertia.

  The gain includes a position loop gain and a speed loop gain, and is used by the speed control unit 64, the speed feedforward control unit 90, the acceleration feedforward control unit 92, and the like. A filter having a predetermined cutoff band, such as a torque filter, is appropriately used when various signals are transmitted. However, since such a gain and a filter are well-known, detailed description is abbreviate | omitted.

  After classifying the control parameters in step 310, in step 320, only control parameters for which an appropriate value can be determined by interpolation are calculated. For each control parameter, for example, acceleration / deceleration time constant and reverse correction value, a linear interpolation graph and / or a curve interpolation graph are obtained in advance through experiments or the like and stored in the storage unit 82. FIGS. 10A and 10B are graphs of linear interpolation and curve interpolation showing the relationship between the inertia and / or the friction coefficient and the control parameter, respectively. In step 320, control parameters are determined based on the graph of such linear interpolation or curved interpolation.

  On the other hand, in step 330, a control parameter that changes stepwise with respect to the friction coefficient and / or inertia is determined. A graph of a step function for each control parameter, for example, various gains, filters, etc., is obtained by experiments and stored in the storage unit 82. FIG. 10C is a step function graph showing the relationship between the inertia and / or the friction coefficient and the control parameter. In step 330, control parameters are determined based on such a step function graph. Note that depending on the control parameter, only the relationship between one of the friction coefficient and the inertia may be required.

  Thus, in the present invention, the calculation method is changed according to the type of the control parameter. For this reason, the control parameter can be calculated more precisely, and as a result, the numerically controlled machine tool 10 can be controlled with higher speed and higher accuracy. Furthermore, the numerically controlled machine tool 10 can be controlled stably and effectively even when the control parameters are switched.

DESCRIPTION OF SYMBOLS 10 Numerical control machine tool 12 Bed 16 Column 20 Spindle 22 Tool 26 Nut 28 Z-axis guide rail 36 X-axis guide rail 40 Numerical control part 44 Program reading interpretation part 48 Program execution command part 50 Distribution control part 54 Feed axis motor drive part 56 Operation control unit (parameter setting device)
Reference Signs List 60 position control unit 64 speed control unit 72 current detector 74 temperature sensor 76 calculation unit 80 processing management system 82 storage unit 84 determination unit 86 setting unit 92 acceleration feedforward control unit 96 torque calculation unit 98 parameter calculation unit W work

Claims (10)

In the parameter setting method to set the control parameter of the feed axis of the machine tool,
Determining whether the inertia of the load placed on the machine tool is stored in the storage unit;
When the inertia is not stored in the storage unit, the inertia of the load is measured and stored, and when the inertia is stored in the storage unit, the stored inertia is read.
Calculate control parameters of the feed axis of the machine tool based on the measured or read inertia of the load,
A parameter setting method, wherein the calculated control parameter is set for the feed axis of the machine tool. In a parameter setting method for setting a control parameter of one feed axis among a plurality of feed axes of a machine tool,
Determining whether the inertia of the load placed on the machine tool for the one feed axis is stored in the storage unit;
When the inertia is not stored in the storage unit, the inertia of the load is measured and stored, and when the inertia is stored in the storage unit, the stored inertia is read.
Calculate the control parameter of the one feed axis of the machine tool based on the measured or read inertia of the load,
A parameter setting method, comprising: setting a calculated control parameter for the one feed axis of the machine tool.   The parameter setting method according to claim 1, wherein the storage unit stores a friction coefficient of coulomb friction and viscous friction of a feed shaft, and the control parameter is calculated based on the friction coefficient and the inertia. .   4. The parameter setting method according to claim 3, wherein a control parameter that changes in accordance with the friction coefficient and the inertia, and a control parameter that is set to a constant value for each range of the friction coefficient and the inertia value are calculated. .   The storage unit stores a relationship between a motor temperature of a motor that operates the feed shaft of the machine tool and a torque constant of the motor, and the control parameter is based on the relationship, the friction coefficient, and the inertia. The parameter setting method according to claim 3, wherein the parameter setting method is calculated. In the parameter setting device that sets the control parameters of the feed axis of the machine tool,
A determination unit for determining whether inertia of a load placed on the machine tool is stored in a storage unit of a processing management system connected to the machine tool;
When the inertia is not stored in the storage unit, the inertia of the load is measured and stored, and when the inertia is stored in the storage unit, the stored inertia is read and measured. Or a calculation unit for calculating a control parameter of the feed axis of the machine tool based on the read inertia of the load;
A setting unit for setting the control parameter calculated by the calculation unit for the feed axis of the machine tool;
A parameter setting device comprising: In a parameter setting device for setting a control parameter of one feed axis among a plurality of feed axes of a machine tool,
A determination unit for determining whether inertia of a load placed on the machine tool with respect to the one feed axis is stored in a storage unit;
When the inertia is not stored in the storage unit, the inertia of the load is measured and stored, and when the inertia is stored in the storage unit, the stored inertia is read and measured. Or a calculation unit for calculating a control parameter of the one feed axis of the machine tool based on the inertia of the loaded load,
A setting unit for setting the control parameter calculated by the calculation unit for the one feed axis of the machine tool;
A parameter setting device comprising:   The parameter setting device according to claim 6 or 7, wherein the storage unit stores a friction coefficient of coulomb friction and viscous friction of a feed shaft, and the control parameter is calculated based on the friction coefficient and the inertia. .   9. The parameter setting device according to claim 8, wherein a control parameter that changes according to the friction coefficient and the inertia, and a control parameter that is set to a constant value for each range of the friction coefficient and the inertia value are calculated. .   The storage unit stores a relationship between a motor temperature of a motor that operates the feed shaft of the machine tool and a torque constant of the motor, and the control parameter is based on the relationship, the friction coefficient, and the inertia. The parameter setting device according to claim 6 or 7, wherein the parameter setting device is calculated.

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