Numerical control device, control system and control method

Abstract

A numerical control device (10) that controls a machine tool (20) is characterized by comprising: a receiving unit (13) that receives detection data that detects state quantities used to monitor the state of the machine tool (20); a model creation unit (14) that creates an interpolation model for interpolating the detection data using control information based on the control information and the detection data that the numerical control device (10) has; and a correction unit (15) that interpolates the detection data using the interpolation model.

Description

[Technical field]

[0001] The present disclosure relates to a numerical control device, a control system, and a control method that collect detection data from a detection device. [Background technology]

[0002] In a numerical control device, detection data obtained by a sensor that detects the state quantity of the machine tool to be controlled is collected, and the detection data is used to grasp the state of the machine tool and to control the machine tool according to the grasped state. The detection data obtained by the sensor may be lost for some reason, and a technique for interpolating the detection data has been proposed to compensate for the loss of the detection data.

[0003] As an example of a technique for interpolating detection data, Patent Document 1 discloses a technique for interpolating missing detection data by a system model constructed based on a Bayesian network in a system that collects detection data acquired by sensors in a boiler system. In the technique disclosed in Patent Document 1, when detection data is missing, the missing detection data is interpolated by utilizing the correlation between the missing detection data and other detection data. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2022-502737 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above conventional techniques have a problem in that it is sometimes difficult to interpolate missing detection data. For example, the technique disclosed in Patent Document 1 uses correlations between detection data, so it cannot be applied when there is only one type of detection data, and even when multiple types of detection data are acquired, it is not possible to perform interpolation when all types of detection data are missing, and therefore it is not possible to perform interpolation when the detection data does not satisfy the conditions.

[0006] The present disclosure has been made in consideration of the above, and has an object to provide a numerical control device capable of interpolating missing detection data for detection data under a wide range of conditions. [Means for solving the problem]

[0007] In order to solve the above problems and achieve the object, the present disclosure provides a numerical control device for controlling a machine tool, which detects a state quantity of the machine tool. It is time series data Detection data From outside the numerical control device A receiving unit for receiving the signal; Information including control data, which is time-series data generated inside a numerical control device. The present invention includes a model creation unit that creates an interpolation model for interpolating the detection data using the control information based on the control information and the detection data held by the numerical control device, and a correction unit that performs interpolation of the detection data using the interpolation model, and the model creation unit is configured to Control Data Based on the control information for a period of time during which the value exceeds a predetermined threshold, Control Data The method is characterized in that an interpolation model is created for the detection data detected during the period when the value exceeds the threshold value. Effect of the Invention

[0008] According to the present disclosure, it is possible to obtain a numerical control device capable of interpolating missing detection data for detection data under a wide range of conditions. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing a configuration of a control system according to a first embodiment. [Diagram 2] A flowchart for explaining an interpolation model creation process according to the first embodiment. [Diagram 3] FIG. 1 is an explanatory diagram of an interpolation model creation process according to the first embodiment; [Figure 4] A flowchart for explaining the correction process in the first embodiment. [Diagram 5] FIG. 13 is a diagram showing a configuration of a control system according to a second embodiment. [Figure 6] A flowchart for explaining an interpolation model creation process according to the second embodiment. [Figure 7] FIG. 13 is an explanatory diagram of an interpolation model creation process according to the second embodiment; [Figure 8] FIG. 13 is a diagram showing a configuration of a control system according to a third embodiment. [Figure 9] Flowchart for explaining reception processing in the third embodiment [Figure 10] Flowchart for explaining analysis processing in the third embodiment [Figure 11] FIG. 13 shows a configuration of a power supply unit in the third embodiment. [Figure 12] FIG. 1 is a diagram showing dedicated hardware for implementing the functions of the numerical control device according to the first to third embodiments. [Figure 13] FIG. 1 is a diagram showing a configuration of a control circuit for implementing the functions of a numerical control device according to first to third embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, configurations of a numerical control device, a control system, and a control method according to embodiments of the present disclosure will be described in detail with reference to the drawings.

[0011] Embodiment 1 1 is a diagram showing a configuration of a control system 1 according to the embodiment 1. The control system 1 has a numerical control device 10, a machine tool 20, and a temperature sensor 30 which is a detection device installed in the machine tool 20.

[0012] Numerical control device 10 has a control unit 11, a drive unit 12, a receiving unit 13, a model creation unit 14, and a correction unit 15. Machine tool 20 has a motor 21 and a drive unit 22. In addition to temperature sensor 30, machine tool 20 is further provided with a transmission unit 31 that transmits temperature data, which is detection data acquired by temperature sensor 30, via wireless communication, and a power supply unit 32 that supplies power to transmission unit 31.

[0013] The control unit 11 outputs command control information, which is information for operating the drive unit 22. The command control information output by the control unit 11 is input to each of the drive device 12 and the model creation unit 14. The command control information includes at least one of, for example, position, speed, and acceleration commands for the numerical control device 10 to operate the drive unit 22, axis movement information obtained by analyzing the machining program, machining volume, and ON / OFF information for controlling the flow rate of the coolant or chiller.

[0014] Driving device 12 drives driving device 22 by supplying a current for driving driving device 22 of machine tool 20 to motor 21 in accordance with command control information output by control unit 11. Driving device 12 outputs feedback control information to each of control unit 11 and model creation unit 14. The feedback control information is information possessed by driving device 12, and includes at least any of information possessed by driving device 12, such as actual measurement values ​​such as position, speed, and current feedback used in feedback control, position deviation, speed deviation, estimated disturbance calculated by driving device 12, and motor temperature information acquired by driving device 12.

[0015] The receiving unit 13 receives, via wireless communication, temperature data output by a temperature sensor 30, which is a detection device installed in the machine tool 20. The temperature data is data indicating a detected temperature value at a location of the machine tool 20 where the temperature sensor 30 is installed, and is an example of detection data that detects a state quantity of the machine tool 20. The detection data is used to monitor the state of the machine tool 20. The receiving unit 13 can output the received temperature data to each of the model creation unit 14 and the correction unit 15.

[0016] The model creation unit 14 creates an interpolation model for interpolating temperature data using the control information based on the control information held by the numerical control device 10 and the temperature data output by the receiving unit 13. Here, "held by the numerical control device 10" in "control information held by the numerical control device 10" means information that the numerical control device 10 originally holds inside the numerical control device 10, not information that the numerical control device 10 acquires from the outside of the numerical control device 10 for creating an interpolation model and interpolating temperature data. For example, the control information held by the numerical control device 10 is information generated by the control unit 11, the driving device 12, etc., and can include command control information generated by the control unit 11, feedback control information generated by the driving device 12, etc. Hereinafter, the control information acquired by the model creation unit 14 will be described as being command control information output by the control unit 11 and feedback control information output by the driving device 12, but the control information acquired by the model creation unit 14 may be control information held by the numerical control device 10. For example, the control information possessed by numerical control device 10 can include not only information used for controlling drive unit 22 of machine tool 20, but also data not used for normal control, such as ON / OFF information which is control information for auxiliary devices in machine tool 20 such as a coolant, a chiller, etc., and temperature data acquired from a temperature protection thermistor (not shown) connected to motor 21 of machine tool 20. The control information possessed by numerical control device 10 can include at least one of the information exemplified above.

[0017] The correction unit 15 performs interpolation of the temperature data using the interpolation model created by the model creation unit 14. Here, the interpolation of the temperature data means that, when the temperature data received by the receiving unit 13 is missing, a predicted value of the missing temperature data is obtained to interpolate the time series data of the temperature data.

[0018] The motor 21 of the machine tool 20 drives the drive unit 22 by the current supplied by the drive device 12. The drive unit 22 operates according to the drive of the motor 21. The drive unit 22 has a plurality of drive shafts, such as a drive shaft for driving a workpiece and a drive shaft for driving a tool, and various operations can be performed by the drive shafts moving according to the drive of the motor 21. As an example, in a ball screw mechanism coupled to the motor 21 by a coupling, the table mechanism connected to the ball screw can be linearly moved with the rotational movement of the motor 21. Since the workpiece is mounted on the table mechanism, the workpiece can be linearly moved by rotating the motor 21. In addition, when the motor 21 is coupled to the tool, the tool can be rotated by driving the motor 21. For example, in a machining center, the workpiece is linearly moved while the tool is rotated based on the command control information commanded by the control unit 11, and the relative position between the tool and the workpiece is controlled to a desired position, thereby making it possible to perform cutting processing. The operations performed by drive unit 22 vary depending on the type and configuration of machine tool 20, and the contents of the operations performed by drive unit 22 are not particularly limited here.

[0019] The temperature sensor 30 is an example of a detection device that detects a state quantity of the machine tool 20. The temperature sensor 30 detects temperature data as a state quantity of the machine tool 20. The temperature sensor 30 outputs the detected temperature data to the transmission unit 31. Here, one temperature sensor 30 is shown for one machine tool 20, but multiple temperature sensors 30 may be installed for one machine tool 20. For example, when the temperature sensor 30 is installed to correct a processing error due to thermal displacement, multiple temperature sensors 30 are installed for one machine tool 20. The detection device is not limited to the temperature sensor 30, and may be any device that can acquire a state quantity that is a physical quantity indicating the state of the machine tool 20. For example, the detection device may be an acceleration sensor, a force sensor, or the like.

[0020] The transmitter 31 transmits the temperature data output by the temperature sensor 30 to the receiver 13 of the numerical control device 10. The transmitter 31 can transmit the temperature data by wireless communication. When wireless communication is used, wiring required for wired communication can be omitted.

[0021] The power supply unit 32 supplies power for wireless communication to the transmission unit 31. The power supply unit 32 is configured by, for example, a power generation element. The power supply unit 32 may also use a power storage element or a non-contact power supply method. When a power generation element is used for the power supply unit 32, it is possible to facilitate maintenance. However, in the power supply unit 32 using a power generation element, if the power generation element does not satisfy a power generation condition, which is a condition for power supply necessary for communication, the transmission unit 31 cannot transmit the temperature data output by the temperature sensor 30. For this reason, if the power supply unit 32 does not satisfy the power generation condition, the reception unit 13 of the numerical control device 10 will receive missing temperature data.

[0022] In addition to cases where the power required for communication cannot be supplied, there are also cases where temperature data is lost due to, for example, a malfunction of the temperature sensor 30 itself or the state of wireless communication between the transmitter 31 and the receiver 13. For this reason, the correction unit 15 of the numerical control device 10 interpolates the lost temperature data. For this reason, the model creation unit 14 creates an interpolation model for interpolating temperature data from the control information based on the received temperature data and control information before the correction unit 15 interpolates the lost temperature data. The operation of the model creation unit 14 will be described in detail below.

[0023] 2 is a flowchart for explaining the interpolation model creation process in the first embodiment. The model creation unit 14 acquires temperature data from the receiving unit 13 (step S101). The model creation unit 14 also acquires control information of the control unit 11 and the driving device 12 (step S102). Specifically, the model creation unit 14 acquires command control information output by the control unit 11 and feedback control information output by the driving device 12 as control information.

[0024] Next, the model creation unit 14 selects control data to be input to the interpolation model from among the control data, which are multiple time-series signals included in the acquired control information (step S103). The control data to be input to the interpolation model is preferably data having a physical correlation with the temperature data. Here, the model creation unit 14 acquires correlation information, which is information indicating a correlation between each of the multiple control data included in the control information and the temperature data, which is the detection data, in advance, and selects the control data to be input to the interpolation model based on the correlation information. Note that, although it is assumed here that one type of control data is selected, the model creation unit 14 may select multiple types of control data for one temperature data as the control data to be input to the interpolation model. For example, it is assumed here that the temperature sensor 30 that acquires the temperature data is installed near the windings of the motor 21 of the machine tool 20, and a current feedback that is correlated with the temperature data near the windings of the motor 21 is selected.

[0025] The resistance loss Q [W] of the current I [A] flowing through the electric resistance Rc [Ω] of the motor 21 can be expressed by the following formula (1). In addition, the temperature rise ΔK [K] due to heat conduction for the thermal resistance Rt [Ω] and the resistance loss Q [W] can be expressed by the following formula (2).

[0026]

number

[0027]

number

[0028] From the above formulas (1) and (2), it is clear that the temperature rise of the windings of motor 21 rises in proportion to the square of the current I, and even when the temperature near motor 21 is acquired by temperature sensor 30, it is expected that there is a correlation between the current feedback and the temperature data. In other words, if an interpolation model is created using current feedback, even if the temperature data of temperature sensor 30 is missing, it is thought that the missing data can be accurately interpolated using the interpolation model from the current feedback at that time.

[0029] Next, the model creation unit 14 judges whether or not the section is an interpolation model creation section based on the acquired control information (step S104). Here, by limiting the interpolation model creation section instead of using data for the entire period, it is possible to create a highly accurate interpolation model by eliminating the influence of current feedback during acceleration / deceleration, which is short relative to the time constant of temperature change, and noise during stopping. For example, the model creation unit 14 can set the section during machining of the machine tool 20 as the interpolation model creation section. In this case, the model creation unit 14 can judge whether or not the section is an interpolation model creation section by using, among the control data included in the control information, control data indicating whether or not the machine tool 20 is machining, for example, control data corresponding to a machining command commanded by a G code. In addition, in determining the model creation section, it is sufficient to determine the control data having a physical correlation with the temperature sensor 30 so that sufficient time resolution and spatial resolution can be obtained to create an interpolation model.

[0030] Next, the model creation unit 14 judges whether or not it is an interpolation model creation section based on the judgment result in step S104 (step S105). If it is an interpolation model creation section (step S105: Yes), the model creation unit 14 creates an interpolation model (step S106). The model creation unit 14 creates the interpolation model based on the temperature data and control information of the interpolation model creation section. The model creation unit 14 can create the interpolation model using, for example, a general regression model, a polynomial model, or the like. If it is not an interpolation model creation section (step S105: No), the processing of step S106 is omitted.

[0031] Fig. 3 is an explanatory diagram of the interpolation model creation process in the first embodiment. Fig. 3 shows temperature data received by the receiving unit 13, control data included in the control information indicating whether machining is in progress, current feedback (referred to as current FB in the figure) which is control data included in the control information and is input to the interpolation model, and an interpolation model for interpolating the temperature data using the current feedback. When the receiving unit 13 receives the temperature data, the model creation unit 14 judges whether it is an interpolation model creation section depending on whether the machine tool 20 is in machining at the time when the temperature data is acquired from the control information, and creates an interpolation model based on the temperature data acquired in the interpolation model creation section and the control information.

[0032] In addition, while an example of creating an interpolation model for temperature data detected during machining of the machine tool 20 based on control information during machining command, i.e., during a machining command, has been shown, the interpolation model creation section is not limited to during the machining command. For example, the model creation unit 14 can create an interpolation model for temperature data detected during a movement command based on control information in a movement command commanding the machine tool 20 to move a drive shaft. Alternatively, when the control information satisfies a predetermined condition, for example, the model creation unit 14 can set a period in which a value of a specific control data in the control information exceeds a predetermined threshold as an interpolation model creation section, and create an interpolation model for temperature data detected in the interpolation model creation section based on the control information of the interpolation model creation section. In addition, the model creation unit 14 can use multiple conditions for determining whether or not it is an interpolation model creation section as described above. For example, when the model creation unit 14 sets the period during a machining command as an interpolation model creation section and further sets the period during a movement command as an interpolation model creation section, the model creation unit 14 can create different interpolation models during the machining command and during the movement command.

[0033] 4 is a flowchart for explaining the correction process in the first embodiment. The correction unit 15 acquires the output of the interpolation model output by the model creation unit 14 (step S201). The correction unit 15 also acquires the temperature data received by the receiving unit 13 (step S202). The correction unit 15 determines whether or not the temperature data from the receiving unit 13 is missing (step S203).

[0034] If the temperature data is missing (step S203: Yes), the correction unit 15 uses an interpolation model to interpolate the temperature data (step S204). At this time, the correction unit 15 acquires control data to be input to the interpolation model, creates interpolation data for the missing temperature data from the control data using the interpolation model, and can replace the temperature data with the interpolation data. Alternatively, the correction unit 15 may interpolate the temperature data using the interpolation data created using previously received temperature data. There is no particular limitation on the method of creating the interpolation data using previously received temperature data, but for example, the correction unit 15 can use the previously received temperature data as it is as the current temperature data. When the time elapsed since the previous reception of temperature data is short, there are cases in which the error between the actual temperature data and the interpolation data can be reduced by inheriting the previous value in this way. In addition, the correction unit 15 may temporally switch the interpolation data used when interpolating the temperature data between the interpolation data obtained by performing interpolation on the temperature data that is the detection data using the interpolation model and the interpolation data obtained by performing interpolation on the detection data using previously acquired temperature data. For example, until the elapsed time since the last time temperature data was received exceeds a predetermined threshold, the temperature data is interpolated using interpolated data created using past temperature data, and after the elapsed time exceeds the threshold, the temperature data is interpolated using interpolated data created using an interpolation model.

[0035] As described above, according to the first embodiment, it is possible to provide a numerical control device 10 for controlling a machine tool 20, which is characterized by including a receiving unit 13 for receiving detection data, such as temperature data, that detects a state quantity of the machine tool 20, a model creating unit 14 for creating an interpolation model for interpolating the detection data using the control information based on the control information possessed by the numerical control device 10 and the received detection data, and a correction unit 15 for interpolating the detection data using the interpolation model. As a result, even if the detection data is missing for some reason, the numerical control device 10 can interpolate the detection data using the control information that has a physical correlation with the detection data, and therefore can acquire continuous detection data. Since the control information used as an input for the interpolation can be acquired inside the numerical control device 10, no particular conditions are imposed on the detection data acquired during the interpolation, and it becomes possible to interpolate the missing detection data for detection data under a wide range of conditions.

[0036] The model creation unit 14 can create an interpolation model for the detection data detected during a movement command based on control information in the movement command that commands the machine tool 20 to move the drive axis. That is, the model creation unit 14 can set the movement command as an interpolation model creation section and create an interpolation model for the detection data detected during the interpolation model creation section. The model creation unit 14 can also create an interpolation model for the detection data detected during a machining command based on control information in a machining command in which the machine tool 20 performs machining. That is, as shown in FIG. 3, the model creation unit 14 can also set the machining command as an interpolation model creation section. The model creation unit 14 can also create an interpolation model for the detection data detected during a period in which the value included in the control information exceeds a predetermined threshold value based on control information for a period in which the value included in the control information exceeds a predetermined threshold value. That is, the model creation unit 14 can also set a period in which the value of the control data included in the control information exceeds a threshold value as an interpolation model creation section. For example, even when no current is actually flowing, the detection value of the detection device may not be zero due to effects such as temperature drift, and may detect a very small current. However, by setting the period in which the detection value of the current sensor exceeds a threshold value as the interpolation model creation section, it is possible to create an interpolation model by excluding the data from the section in which such a small current is detected.

[0037] Furthermore, the model creation unit 14 can generate an interpolation model based on control information including at least one of the acceleration, speed, and position of the drive axis of the machine tool 20.

[0038] The model creation unit 14 can acquire correlation information in advance, which is information indicating the correlation between each of a plurality of control data, which are time-series signals included in the control information, and the detection data, and create an interpolation model based on the correlation information. Specifically, the model creation unit 14 can select control data to be input to the interpolation model based on the correlation information, and create an interpolation model using the selected control data and the detection data.

[0039] Furthermore, the correction unit 15 can interpolate the detection data using the interpolation data created using the interpolation model. Alternatively, the correction unit 15 may temporally switch between the interpolation data created using the interpolation model and the interpolation data created using the detection data, and use the interpolation data used when interpolating the detection data.

[0040] Moreover, according to the first embodiment, it is also possible to provide a control system 1. The control system 1 can include a machine tool 20, a temperature sensor 30 which is a detection device which detects a state quantity of the machine tool 20 and outputs detection data indicating the state quantity, a numerical control device 10 which controls the machine tool 20, a transmission unit 31 which transmits the detection data output by the detection device, a reception unit 13 which receives the detection data transmitted by the transmission unit 31, a control unit 11 which outputs command control information which is information for operating a drive unit 22 of the machine tool 20, a drive unit 12 which drives the drive unit 22 of the machine tool 20 in accordance with the command control information, a model creation unit 14 which creates an interpolation model for interpolating the detection data using the control information based on control information including at least one of the command control information input to the drive unit 12 and the feedback control information output by the drive unit 12 and the detection data, and a correction unit 15 which performs interpolation of the detection data using the interpolation model.

[0041] Moreover, according to the first embodiment, a control method using the control system 1 can also be provided. The control method includes the steps of a detection device, for example, a temperature sensor 30 detecting a state quantity of the machine tool 20 and outputting detection data indicating the state quantity, for example, temperature data, a transmission unit 31 transmitting the detection data output by the detection device, a receiving unit 13 receiving the detection data transmitted by the transmission unit 31, a control unit 11 of the numerical control device 10 outputting command control information which is information for operating a drive unit 22 of the machine tool 20, a drive unit 12 of the numerical control device 10 driving the drive unit 22 in accordance with the command control information, a step in which the drive unit 12 outputs feedback control information when the drive unit 12 drives the drive unit 22, a step in which a model creation unit 14 of the numerical control device 10 creates an interpolation model for interpolating the detection data using the control information based on the control information including at least one of the command control information input to the drive unit 12 and the feedback control information output by the drive unit 12 and the received detection data, and a correction unit 15 of the numerical control device 10 interpolating the detection data using the interpolation model.

[0042] Embodiment 2 5 is a diagram showing a configuration of a control system 2 according to the second embodiment. The control system 2 has a numerical control device 10A instead of the numerical control device 10 of the control system 1.

[0043] The following mainly describes the parts that are different from the control system 1 according to the first embodiment, and omits a description of the parts that are the same as those in the control system 1. The numerical control device 10A has a model creation unit 14A instead of the model creation unit 14 of the numerical control device 10.

[0044] As described in the first embodiment, by interpolating temperature data using control data that has a physical correlation with the temperature data, it is possible to use the temperature data as continuous temperature data even when the temperature data is missing. However, there are many types of control data, and it is sometimes unclear which control data should be used to create an interpolation model that has the strongest correlation with the acquired temperature data.

[0045] Therefore, in the second embodiment, the model creation unit 14A has a correlation calculation unit 141, calculates the degree of correlation between the control data and the temperature data, and creates an interpolation model using the control data selected based on the degree of correlation, thereby enabling more accurate interpolation. For example, the correlation calculation unit 141 selects the control data with the strongest correlation as the control data to be input to the interpolation model.

[0046] FIG. 6 is a flowchart for explaining the interpolation model creation process in the second embodiment. The processes of steps S101, S102, S104, and S105 are the same as those of the first embodiment, and step S103 in FIG. 2 is omitted. If it is an interpolation model creation section (step S105: Yes), the correlation calculation unit 141 of the model creation unit 14A calculates the correlation between the control data and the detection data (step S111). The correlation calculation unit 141 selects the control data with the highest correlation (step S112). The model creation unit 14A creates an interpolation model of the selected control data (step S113). Specifically, the model creation unit 14A creates an interpolation model that receives the selected control data as an input and outputs temperature data.

[0047] Fig. 7 is an explanatory diagram of the interpolation model creation process in the second embodiment. Here, similarly to the first embodiment, the period during which machine tool 20 is in machining is set as the model creation section based on the control data included in the control information and indicating whether machining is in progress. Also, for simplicity, Fig. 7 shows current feedback, acceleration command, and estimated disturbance as examples of candidates for control data to be input to the interpolation model, but the present invention is not limited to these examples.

[0048] In step S111 of FIG. 6, an interpolation model of temperature data is created from each of a plurality of types of control data in the first interpolation model creation section. Then, in the next interpolation model creation section, the correlation between each of the created plurality of interpolation models and the temperature data is calculated, thereby calculating the correlation between each of the plurality of control data and the temperature data. In step S112, the interpolation model determined to have the strongest correlation is used for the interpolation of the correction unit 15. In the example of FIG. 7, the correlation of the interpolation model created using the current feedback is 80%, the correlation of the interpolation model created using the acceleration command is 20%, and the correlation of the model created using the estimated disturbance is 60%, so that the current feedback with the highest correlation is used to perform the interpolation of the correction unit 15. Note that, although an interpolation model is created only in the first interpolation model creation section here, the update of the interpolation model may be repeated successively.

[0049] As described above, according to the second embodiment, the control information includes a plurality of control data that are time-series signals, and the correlation calculation unit 141 is further provided to calculate the magnitude of correlation between each of the plurality of control data included in the control information and the detection data, and the model creation unit 14A can select the control data to be used when creating an interpolation model based on the correlation. This allows the control data to be input to the interpolation model when creating the interpolation model based on the actually calculated correlation. Therefore, it is possible to perform interpolation with higher accuracy.

[0050] Embodiment 3 FIG. 8 is a diagram showing a configuration of a control system 3 according to a third embodiment. The control system 3 has a numerical control device 10B instead of the numerical control device 10 of the control system 1. When the power supply unit 32 is configured to supply power to the transmission unit 31 using a power generation element, it is assumed that the output of the temperature sensor 30 will be lost because the power generation condition of the power generation element is not satisfied, as shown in the first and second embodiments. The control system 3 according to the third embodiment has a function of analyzing in advance whether the power supply unit 32 satisfies the power generation condition, and a function of switching the power supply means of the power supply unit 32 according to the analysis result. A specific configuration will be described below.

[0051] The numerical control device 10B has a control unit 11, a driving unit 12, a receiving unit 13B, and an analysis unit 16. Note that, for simplicity, the model creation unit 14 and the correction unit 15 of the numerical control device 10B are omitted here, but the numerical control device 10B may have the model creation unit 14 and the correction unit 15.

[0052] Receiving unit 13B has a storage unit 131 that stores command control information and feedback control information when temperature data is received from transmitting unit 31, that is, when power supplying unit 32 satisfies the power generation condition and temperature data is transmitted from transmitting unit 31. If temperature data is lost, receiving unit 13B does not store command control information and feedback control information in storage unit 131. Storage unit 131 is a physical memory such as a ROM (Read Only Memory).

[0053] 9 is a flowchart for explaining the reception process in the third embodiment. The reception unit 13B judges whether or not temperature data has been acquired from the transmission unit 31 (step S301). If temperature data has been acquired (step S301: Yes), the reception unit 13B stores the control information in the storage unit 131 (step S302). If temperature data has not been acquired (step S301: No), the reception unit 13B omits the process of step S302.

[0054] The analysis unit 16 analyzes whether the transmission unit 31 is capable of transmitting temperature data before the operation of the drive unit 22 at the time of a machining program command. The analysis unit 16 compares the analysis result of the command control information output by the control unit 11 with the data stored in the storage unit 131 to analyze whether the reception unit 13B satisfies the reception condition, that is, whether the power supply unit 32 satisfies the power generation condition, and outputs the analysis result to the power supply unit 32.

[0055] 10 is a flowchart for explaining the analysis process in the embodiment 3. The analysis unit 16 analyzes the command control information output by the control unit 11 (step S401). The analysis unit 16 compares the data stored in the storage unit 131 with the analysis result (step S402).

[0056] For example, the analysis unit 16 analyzes the command control information to obtain data of the same type as the data stored in the storage unit 131, and compares it with the data stored in the storage unit 131. The control data to be compared among the control data contained in the control information stored in the storage unit 131 to be compared may be feedback control information of the drive unit 12. Since the drive shaft has not yet been operated, there is no certainty regarding the control information of the drive unit 12. However, for example, if the numerical control device 10B has a machine and disturbance model, it is possible to obtain the control data contained in the feedback control information as an estimated value from the command control information and compare it with the value stored in the storage unit 131. Specifically, as shown in the following formula (3), the analysis unit 16 obtains the command angular acceleration α [rad / s 2 ] to the moment of inertia J [kg m 2 The torque constant K is the torque obtained by adding the disturbance component D [N m] to the inertia force multiplied by t Dividing by [N m / A] gives the current feedback I fb The analysis unit 16 can obtain an estimated value of the current feedback I fb The estimated value of is compared with the control data stored in the memory unit 131.

[0057]

number

[0058] The analysis unit 16 determines whether the reception condition is satisfied based on the comparison result (step S403). The analysis result of the analysis unit 16 is output to the power supply unit 32.

[0059] 11 is a diagram showing a configuration of the power supply unit 32 in the third embodiment. The power supply unit 32 has a power generating element 321, a power storage element 322, and a switch unit 323 that switches between the power supplied by the power generating element 321 and the power supplied by the power storage element 322 to be supplied to the transmission unit 31. The switch unit 323 switches its state according to the analysis result output by the analysis unit 16. When the analysis result output by the analysis unit 16 indicates that the reception condition is satisfied, that is, when the power generation condition is achieved, the switch unit 323 is in a state where the power is supplied from the power generating element 321 to the transmission unit 31, and when the analysis result indicates that the reception condition is not satisfied, that is, when the power generation condition is not achieved and the power generation condition is not achieved, the switch unit 323 is in a state where the power is supplied from the power storage element 322 to the transmission unit 31.

[0060] In this way, the analysis unit 16 predicts in advance cases where the power generation conditions will not be satisfied and switches to power supply from the storage element 322, thereby preventing loss of temperature data caused by an interruption in the power supply to the transmission unit 31, and the numerical control device 10B can continuously acquire temperature data from the temperature sensor 30.

[0061] When the power generation element 322 is used, the power generation element 321 can be omitted, but using the power generation element 321 and the power storage element 322 in combination has the advantage of extending the maintenance interval of the power storage element 322. In addition, instead of the power storage element 322, external power may be supplied by non-contact power supply.

[0062] As described above, according to the third embodiment, the receiver 13B of the numerical control device 10B can receive the detection data transmitted by the transmitter 31 via wireless communication, and store the control information at the time when the transmitter 31 transmitted the detection data in the storage unit 131. Storing the control information at the time when the detection data was received from the transmitter 31 makes it possible for the receiver 13B to grasp the conditions under which the detection data can be acquired.

[0063] The numerical control device 10B further includes an analysis unit 16 that analyzes the control information before the driving unit 22 operates. Before the driving unit 22 actually operates, the analysis unit 16 refers to the control information stored by the receiving unit 13B and determines whether or not the transmitting unit 31 satisfies a transmission condition that allows wireless communication. In the second embodiment, terms such as "transmission condition", "reception condition", and "power generation condition" are used, but here, it is considered that if the power supply unit 32 satisfies the "power generation condition", the transmitting unit 31 satisfies the "transmission condition", and if the transmitting unit 31 satisfies the "transmission condition", the receiving unit 13B satisfies the "reception condition". In reality, even if the transmitting unit 31 can transmit, the receiving unit 13B cannot receive. However, here, it is considered that all conditions are satisfied when any of the "transmission condition", "reception condition", and "power generation condition" is satisfied. By including the analysis unit 16, the numerical control device 10B can determine whether or not it is possible to acquire detection data before operating the machine tool 20.

[0064] Furthermore, the numerical control device 10B has a power generating element 321 that supplies generated power to the transmission unit 31, and a power storage element 322 that supplies stored power to the transmission unit 31, and when the analysis unit 16 determines that the transmission condition is satisfied, power is supplied from the power generating element 321 to the transmission unit 31, and when the analysis unit 16 determines that the transmission condition is not satisfied, power is supplied from the power storage element 322 to the transmission unit 31. By using the power generating element 321 and the power storage element 322 in combination, even when the power generating element 321 cannot supply power to the transmission unit 31, it becomes possible to supply power to the transmission unit 31, preventing loss of detection data and enabling the numerical control device 10B to obtain continuous detection data.

[0065] As described above, in the control system 3, the receiver 13B stores the control information when the transmission condition is satisfied in the storage unit 131, and it becomes possible to determine whether or not the transmission condition is satisfied before operating the drive unit 22 when a machining program is commanded, based on the control information at the time of command and the stored control information. This makes it possible to determine whether or not the transmission condition is satisfied before a machining operation, and by taking measures such as switching the power supply path from the combined power storage element 322 to the transmitter 31, it becomes possible for the numerical control device 10B to obtain continuous detection data.

[0066] Next, the hardware configuration of the numerical control devices 10, 10A, and 10B according to the first to third embodiments will be described. The functions of the control unit 11, the driving unit 12, the model creation unit 14, and the correction unit 15 are realized by processing circuits. These processing circuits may be realized by dedicated hardware, or may be control circuits using a CPU (Central Processing Unit).

[0067] When the above processing circuits are realized by dedicated hardware, they are realized by a processing circuit 90 shown in Fig. 12. Fig. 12 is a diagram showing dedicated hardware for realizing the functions of the numerical control devices 10, 10A, and 10B according to the first to third embodiments. The processing circuit 90 is a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination of these.

[0068] When the above processing circuit is realized by a control circuit using a CPU, the control circuit is, for example, a control circuit 91 having a configuration shown in FIG. 13. FIG. 13 is a diagram showing a configuration of the control circuit 91 for realizing the functions of the numerical control devices 10, 10A, and 10B according to the first to third embodiments. As shown in FIG. 13, the control circuit 91 includes a processor 92 and a memory 93. The processor 92 is a CPU, and is also called a processing device, an arithmetic device, a microprocessor, a microcomputer, a DSP (Digital Signal Processor), or the like. The memory 93 is, for example, a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM, a flash memory, an EPROM (Erasable Programmable ROM), or an EEPROM (registered trademark) (Electrically EPROM), a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, or a DVD (Digital Versatile Disk).

[0069] When the above processing circuit is realized by the control circuit 91, it is realized by the processor 92 reading and executing a program corresponding to the processing of each component, which is stored in the memory 93. The memory 93 is also used as a temporary memory for each processing executed by the processor 92. The program executed by the processor 92 may be provided in a state stored in a storage medium, or may be provided via a communication path such as the Internet.

[0070] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or the embodiments may be combined with each other. Also, parts of the configurations may be omitted or modified without departing from the spirit of the invention.

[0071] For example, in the above first to third embodiments, numerical control devices 10, 10A, 10B are described as devices separate from machine tool 20, but numerical control devices 10, 10A, 10B may be built into machine tool 20. In addition, temperature sensor 30, transmission unit 31 and power supply unit 32 may be regarded as parts of numerical control devices 10, 10A, 10B or machine tool 20.

[0072] Further, in the above first to third embodiments, for simplicity, only one temperature sensor 30, which is one type of detection device, is shown, but a plurality of temperature sensors 30 may be installed on one machine tool 20, or a plurality of types of detection devices may be installed. Alternatively, one or a plurality of detection devices other than the temperature sensor 30 may be installed on one machine tool 20. [Explanation of symbols]

[0073] 1, 2, 3 control system, 10, 10A, 10B numerical control device, 11 control unit, 12 drive unit, 13, 13B receiving unit, 14, 14A model creation unit, 15 correction unit, 16 analysis unit, 20 machine tool, 21 motor, 22 drive unit, 30 temperature sensor, 31 transmission unit, 32 power supply unit, 90 processing circuit, 91 control circuit, 92 processor, 93 memory, 131 storage unit, 141 correlation calculation unit, 321 power generation element, 322 power storage element, 323 switch unit.

Claims

1. A numerical control device for controlling a machine tool, a receiving unit that receives detection data obtained by detecting a state quantity of the machine tool, a model creation unit that creates an interpolation model for interpolating the detection data using the control information based on the control information possessed by the numerical control device and the detection data, a correction unit that performs interpolation of the detection data using the interpolation model, comprising: The model creation unit creates the interpolation model for the detection data detected during a period in which a value included in the control information exceeds a predetermined threshold value, based on the control information during the period in which the value exceeds the threshold value. A numerical control device characterized by that.

2. The control information includes at least one of command control information for operating a drive shaft of the machine tool, control information for auxiliary equipment in the machine tool, feedback control information possessed by a drive device for driving a drive mechanism of the machine tool, and detection data acquired by the drive device. The numerical control device according to claim 1, characterized by that.

3. The model creation unit creates the interpolation model for the detection data detected during the movement command based on the control information in the movement command for commanding movement of the drive shaft of the machine tool. The numerical control device according to claim 1, characterized by that.

4. The model creation unit creates the interpolation model for the detection data detected during the machining command based on the control information in the machining command for the machine tool to perform machining. The numerical control device according to claim 1, characterized by that.

5. The model creation unit generates the interpolation model based on the control information including at least one of acceleration, speed, and position of a drive shaft of the machine tool. The numerical control device according to claim 1, characterized by that.

6. The model creation unit previously acquires correlation information, which is information indicating the correlation between each of a plurality of control data that are time-series signals included in the control information and the detection data, and creates the interpolation model based on the correlation information. The numerical control device according to any one of claims 1 to 5, characterized in that.

7. A numerical control device for controlling a machine tool, a receiving unit that receives detection data obtained by detecting a state quantity of the machine tool; a model creation unit that creates an interpolation model for interpolating the detection data using the control information based on the control information possessed by the numerical control device and the detection data; a correction unit that performs interpolation of the detection data using the interpolation model; comprising: The correction unit temporally switches and uses the interpolation data used for interpolating the detection data among the interpolation data obtained by performing interpolation on the detection data using the interpolation model and the interpolation data obtained by performing interpolation on the detection data using the detection data acquired in the past with respect to the detection data. A numerical control device characterized by that.

8. The control information includes a plurality of control data that are time-series signals, a correlation calculation unit that calculates the magnitude of the correlation between each of the plurality of control data included in the control information and the detection data; further comprising: The model creation unit selects the control data used for creating the interpolation model based on the correlation. The numerical control device according to any one of claims 1 to 5, characterized in that.

9. The receiving unit receives the detection data transmitted by the transmitting unit by wireless communication, and stores the control information at the time when the transmitting unit transmits the detection data in a storage unit. The numerical control device according to claim 1, characterized in that.

10. A numerical control device for controlling a machine tool, a receiving unit that receives detection data obtained by detecting a state quantity of the machine tool; A model creation unit that creates an interpolation model for interpolating the detection data using the control information based on the control information possessed by the numerical control device and the detection data; A correction unit that performs interpolation of the detection data using the interpolation model; and includes: The receiving unit receives the detection data transmitted by the transmitting unit through wireless communication, and stores the control information at the time when the transmitting unit transmits the detection data in the storage unit, An analysis unit that analyzes the control information before the driving unit of the machine tool operates; further includes: The analysis unit refers to the control information stored by the receiving unit before the operation, and determines whether or not the transmission condition, which is a condition under which the transmitting unit can perform wireless communication, is satisfied. A numerical control device characterized by this.

11. It has a power generation element that supplies power to the transmitting unit with the generated power and a power storage element that supplies power to the transmitting unit with the stored power. When the analysis unit determines that the transmission condition is satisfied, power is supplied from the power generation element to the transmitting unit. When the analysis unit determines that the transmission condition is not satisfied, power is supplied from the power storage element to the transmitting unit. The numerical control device according to claim 10, characterized by this.

12. A machine tool; A detection device that detects a state quantity of the machine tool and outputs detection data indicating the state quantity; A numerical control device that controls the machine tool; A transmitting unit that transmits the detection data output by the detection device; and includes: The numerical control device includes: A receiving unit that receives the detection data transmitted by the transmitting unit; A model creation unit that creates an interpolation model for interpolating the detection data using the control information based on the control information possessed by the numerical control device and the detection data; A correction unit that performs interpolation of the detection data using the interpolation model; having, The model creation unit creates an interpolation model for the detection data detected during a period in which a value included in the control information exceeds a predetermined threshold value, based on the control information during the period in which the value exceeds the predetermined threshold value. A control system characterized by that.

13. A step in which a detection device detects a state quantity of a machine tool and outputs detection data indicating the state quantity; A step in which a transmission unit transmits the detection data output by the detection device; A step in which a reception unit of a numerical control device receives the detection data transmitted by the transmission unit; A step in which a model creation unit of the numerical control device creates an interpolation model for interpolating the detection data using the control information, based on the control information possessed by the numerical control device and the received detection data; A step in which a correction unit of the numerical control device performs interpolation of detection data using the interpolation model; including, In the step of creating the interpolation model, the model creation unit creates the interpolation model for the detection data detected during the period in which the value exceeds the predetermined threshold value, based on the control information during the period in which the value included in the control information exceeds the predetermined threshold value. A control method characterized by that.

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