Motor drive device and motor drive system

Abstract

In order to address the problem that during operation, the estimated value of the characteristic of a motor (301) or a drive mechanism (302) changes significantly due to the influence of changes in operating conditions such as changes in operating mode, changes in workpieces, and implementation of operations with interference, the following motor drive device (100) and motor drive system (1) are provided. They have a characteristic estimation indication acquisition unit (112). The characteristic estimation indication acquisition unit (112) acquires a characteristic estimation indication signal (C1) indicating whether to perform estimation based on the operating conditions from the outside of the motor drive device (100). When the characteristic estimation indication signal (C1) indicates that no estimation is to be performed, no estimation is performed, so that the estimated value of the characteristic can be used without being affected by changes in operating conditions.

Description

Technical Field

[0001] The present invention relates to a motor drive device and a motor drive system for driving a drive mechanism using a motor. Background Art

[0002] The motor drive device is used to drive the drive mechanism by the motor. As a drive mechanism, there is, for example, a processing table that is moved by driving a ball screw, which is used for a working machine in a production line. The motor drive device estimates the estimated values ​​of the characteristics such as friction and vibration of the motor or the drive mechanism for abnormality diagnosis and characteristic compensation.

[0003] In the conventional motor drive system, for example, a drive command from a numerical control device different from the work operation for production is used to make the worktable perform a movement stop action of a unit movement amount multiple times in one direction and a movement stop action of a unit movement amount multiple times in the opposite direction, and the friction value is calculated by friction measurement. Furthermore, for example, it is determined whether the friction value falls within the allowable range to perform fault diagnosis (for example, refer to Patent Document 1).

[0004] In addition, in the initial stage of starting the driving mechanism, a test run operation specified by a servo adjustment unit is performed to measure load characteristics and perform load characteristic compensation in order to adjust the servo (for example, refer to Patent Document 2).

[0005] Patent Document 1: Japanese Patent Application Publication No. 2004-362204

[0006] Patent Document 2: International Publication No. 2014 / 156164 Summary of the invention

[0007] However, the above-mentioned motor drive device and motor drive system have the following problems. That is, due to changes in operating conditions such as changes in operating modes caused by work plans, changes in the types of workpieces, and implementation of operations with interference during operation, the estimated values ​​of characteristics such as friction and vibration vary significantly due to these changes, making abnormal diagnosis, characteristic compensation, etc. difficult.

[0008] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a motor drive device capable of utilizing an estimated value of a characteristic without being affected by a change in operating conditions.

[0009] The motor drive device according to the present invention comprises: a drive detection value acquisition unit, which acquires a drive detection value based on the position or speed of the motor that drives the drive mechanism through the motor; a drive instruction acquisition unit, which acquires a drive instruction signal that becomes a target value of the drive detection value; a drive control unit, which performs a control operation in a manner such that the drive detection value follows the drive instruction signal, causes current to flow to the motor, and causes the motor to perform a driving action; a characteristic estimation instruction acquisition unit, which acquires a characteristic estimation instruction signal from the outside, and the characteristic estimation instruction signal indicates whether to estimate the characteristic value of the motor or the drive mechanism based on the operating conditions of the driving action determined by the drive instruction signal; and a characteristic estimation unit, which estimates the characteristic value based on the control state value used in the control operation of the drive control unit when the characteristic estimation instruction signal indicates that an estimation is to be performed, and outputs the characteristic estimation value, and does not perform the estimation when the characteristic estimation instruction signal indicates that no estimation is to be performed.

[0010] Effects of the Invention

[0011] According to the present invention, it is possible to output a characteristic estimation value that is not affected by a change in operating conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic configuration diagram showing a motor drive system according to Embodiment 1 of the present invention.

[0013] Figure 2 It is a diagram for explaining the operation of the motor drive system according to the first embodiment of the present invention.

[0014] Figure 3 It is a diagram for explaining the operation of the motor drive system according to the second embodiment of the present invention.

[0015] Figure 4 It is a schematic configuration diagram showing a motor drive system according to a third embodiment of the present invention.

[0016] Figure 5 It is a diagram for explaining the operation of the motor drive system according to the third embodiment of the present invention.

[0017] Figure 6 It is a schematic configuration diagram showing a motor drive system according to a fourth embodiment of the present invention.

[0018] Figure 7 It is a diagram for explaining the operation of the motor drive system according to the fourth embodiment of the present invention. DETAILED DESCRIPTION

[0019] Implementation method 1.

[0020] Figure 11 is a schematic diagram showing a motor drive system according to a first embodiment of the present invention. Figure 1 In the embodiment, the motor drive system 1 includes a motor drive device 100 , a host controller 200 , a drive unit 300 , and a detector 400 .

[0021] The driving unit 300 is composed of a motor 301 and a driving mechanism 302, which are mechanically connected to each other and driven by the motor 301. The driving mechanism 302 is, for example, a processing table that moves the table in a linear direction by rotating a ball screw inside the machine tool. The motor 301 is, for example, a servo motor, and the ball screw is mechanically connected to the rotating output shaft of the motor 301 through a coupling to be driven. Figure 1 In the figure, the motor 301 and the driving mechanism 302 are connected by two lines, and the two lines represent a mechanical connection.

[0022] The detector 400 is provided at the motor 301 , for example, detects the driving position of the motor 301 , and outputs the detected position as a driving detection value Xb to the motor driving device 100 .

[0023] The motor drive device 100 includes a drive control unit 101, a drive command acquisition unit 102, a drive detection value acquisition unit 103, a current detection unit 104, a characteristic estimation unit 111, and a characteristic estimation instruction acquisition unit 112. The drive detection value acquisition unit 103 acquires the position of the motor 301 from the detector 400 as the drive detection value Xb. The drive command acquisition unit 102 acquires the target value for the position of the motor 301 from the upper controller 200 as the drive command signal Xr. The drive control unit 101 performs control calculation based on the drive command signal Xr and the drive detection value Xb, applies a voltage to the motor 301 to flow the current Im, causes the motor 301 to generate a drive torque, and drives the motor 301 in such a manner that the drive detection value Xb follows the drive command signal Xr. The current detection unit 104 detects the current Im flowing to the motor 301 in the motor drive device 100, and transmits it to the drive control unit 101 as the current detection value Ib. In addition, the drive control unit 101 outputs the calculated values ​​in the middle of the control operation until the value of the voltage output for flowing the current Im through the motor 301 is calculated based on the drive command signal Xr, the drive detection value Xb, and the current detection value Ib, or information such as the electrical or mechanical constants of the motor 301 and the mechanical constants of the drive mechanism 302 required for estimating the characteristics of the drive unit 300, as the control state value D1 to the characteristic estimation unit 111. The control state value D1 includes, for example, the detected value of the speed of the motor 301, the detected value of the current of the component that causes the motor 301 to generate torque, the torque constant converted from the detected value of the current to the torque output value of the motor 301, and the load inertia moment constant obtained by adding the inertia moment value of the rotor of the motor 301 and the inertia moment value of the portion of the drive mechanism 302 driven by the motor 301.

[0024] Characteristics estimation instruction acquisition unit 112 acquires characteristics estimation instruction signal C1 from host controller 200 outside motor drive device 100 . Characteristics estimation unit 111 acquires control state value D1 from drive control unit 101 , and outputs characteristics estimation value E1 in accordance with characteristics estimation instruction signal C1 acquired from external host controller 200 .

[0025] Here, the characteristic estimation instruction signal C1 is a signal indicating whether to estimate the characteristic value of the motor 301 or the drive mechanism 302 based on the operating conditions of the driving action determined by the drive command signal Xr. When the characteristic estimation instruction signal C1 indicates to estimate, the characteristic estimation unit 111 estimates the state of the drive unit 300 based on the control state value D1 obtained from the drive control unit 101, and outputs the estimated value as the characteristic estimation value E1. For example, as the characteristic estimation value E1, the total value of the friction torque of the motor 301 and the friction force of the drive mechanism 302 is estimated as the friction component output from the torque of the motor 301, and the friction estimation value is output. The friction is explained by the following example, that is, the dynamic friction, which is the Coulomb friction whose size changes due to the normal force generated by the load, is dominant, and the viscous friction added due to the speed is small and can be ignored.

[0026] The characteristic estimation unit 111 estimates the friction as the characteristic estimation value E1, for example, as described below. The characteristic estimation unit 111 receives, for example, the detected value of speed, the detected value of current, the torque constant for converting current into torque, and the load moment of inertia constant from the drive control unit 101 as the control state value D1. Next, the detected value of current is multiplied by the torque constant to calculate the generated load torque. In addition, the acceleration torque for generating acceleration is calculated by multiplying the acceleration obtained by time-differentiating the detected value of speed by the load moment of inertia constant. If the acceleration torque is subtracted from the calculated load torque, the torque required for the driving action in addition to the acceleration is calculated, and is set as the instantaneous estimated value of friction when it is considered that there is no interference torque. After taking the absolute value, the instantaneous estimated value of friction is passed through a filter such as a first-order lag system with a predetermined time constant to become an average value, which is set as the estimated value of friction.

[0027] When the characteristic estimation instruction signal C1 indicates that the estimation is not to be performed, the characteristic estimation unit 111 does not estimate the characteristic estimation value E1. In the estimation of the characteristic value, when there is a stored variable that is stored in operation, such as the integral variable of the filter of the first-order lag system, during the period when the characteristic estimation instruction signal C1 indicates that the estimation is not to be performed, the stored variable is not updated but stored and the estimation is interrupted. When the characteristic estimation instruction signal C1 again indicates that the estimation is to be performed, the updating of the stored variable is restarted and the estimation is performed. As another method, the following method may be used, that is, during the period when the characteristic estimation instruction signal C1 indicates that the estimation is not to be performed, the estimation is stopped, the stored variable is not updated or is set to a predetermined value. When the characteristic estimation instruction signal C1 again indicates that the estimation is to be performed, the stored variable is set to a predetermined value such as an initial value, and the stored variable is updated from this time to perform the estimation. Regarding the characteristic estimation value E1 output when no estimation is performed, for example, the characteristic estimation value E1 before the characteristic estimation instruction signal C1 is about to be changed to an instruction not to perform estimation is stored. As the characteristic estimation value E1 output when no estimation is performed, a predetermined value may be output so that a device or operator outside the motor drive device 100 can recognize that no estimation of the characteristic estimation value E1 is performed.

[0028] Here, the host controller 200 generates a drive command signal Xr that is a target value of a drive detection value Xb obtained based on the position or speed of the motor 301 , and transmits the signal to the motor drive device 100 .

[0029] During operation, for example, in a working machine as a production equipment having a driving unit 300, it is necessary to drive a plurality of motors 301 installed in the working machine in sequence at an appropriate timing, and to drive the plurality of motors 301 synchronously at the same time, based on a light shielding sensor that detects whether a workpiece is input. Figure 1 The motor 301 is driven based on sensor input states of a plurality of sensor devices not shown in the figure.

[0030] Therefore, in the working operation, the following system structure is often used, that is, unlike the test operation when the motor drive device 100 and the drive unit 300 are started up in the production equipment, etc., the motor drive device 100 is connected to the upper controller 200, and the upper controller 200 generates a drive command signal Xr that is a target value of the detection value obtained based on the position or speed of the motor 301 according to the work plan and transmits it to the motor drive device 100, and the motor drive device 100 obtains the drive command signal Xr from the upper controller 200 outside the motor drive device 100 to drive the motor 301. In addition, in the upper controller 200, since the operating conditions are known from the operating program as the work plan, etc., it is often possible to generate the characteristic estimation instruction signal C1 based on the operating conditions.

[0031] The acquisition of the characteristic estimation instruction signal C1 at the motor drive device 100 may be via serial communication or via parallel digital signal input. When the drive instruction signal Xr from the upper controller 200 or the like is acquired by the motor drive device 100 via communication, if the characteristic estimation instruction signal C1 is acquired via the same communication path as the communication path for receiving the drive instruction signal Xr, fewer communication circuits and communication wiring are required, and it is also easy to synchronize the drive instruction signal Xr and the characteristic estimation instruction signal C1. When the characteristic estimation instruction signal C1 is acquired via parallel digital signal input, the characteristic estimation instruction signal C1 can be acquired from a variety of upper controllers 200 or the like without being restricted by communication protocols or the like.

[0032] Figure 2 1 is a diagram for explaining the operation of the motor drive system 1. It is an example in which the friction of the ball screw of the processing table is estimated as the characteristic estimation value E1 in the example of the operation of the processing table which is driven by the motor 301 and carries the workpiece and moves by the ball screw. For comparison, the case where the friction is always estimated without providing the characteristic estimation instruction signal C1 is shown in time series. Figure 2 The working operation is the operation when the drive unit is performing normal operation, for example, the operation when a working machine as a production equipment having a drive unit is working for normal production. Figure 2In the period 511, the workpiece W1 is operated, and in the period 512, the type of the workpiece is changed to the workpiece W2 whose load is lighter than the workpiece W1, and the workpiece W1 is operated. In the periods 513, 514, and 515, the type of the workpiece is changed again, and the workpiece W1 is operated. There are two operation modes. During the periods 511, 512, and 513, the operation mode P1 is used for operation, and during the period 514, the operation mode P2 is changed, and during the period 515, the operation mode P1 is returned to for operation. P2 is an operation mode in which the interval time from the processing of a certain workpiece to the processing of the next workpiece is longer than the operation mode P1.

[0033] In period 512 , since the type of workpiece is changed to W2 and the load becomes lighter, the friction at the ball screw that moves the table on which the workpiece is placed becomes smaller, and the friction estimation value always changes to a smaller value than that in period 511 .

[0034] During period 514, the processing of the workpiece and the interval time between processing become longer, and the heat dissipation of the ball screw during the interval time becomes larger, so the temperature of the ball screw is lower than that during period 513. The temperature decrease causes the friction to increase, and the estimated friction value always becomes a value larger than that during period 513.

[0035] For example, when the friction value is displayed as an indicator of the aging change of the motor 301 and the drive mechanism 302 during operation, if the estimated friction value changes significantly due to changes in operating conditions such as changes in the type of workpiece and changes in the operating mode as described above, and the displayed output value changes, it will be difficult for an operator who monitors the drive mechanism 302 to understand the characteristics of the drive mechanism 302.

[0036] Therefore, for example, as a reference for observing the time-dependent change caused by friction, the operator decides to estimate the friction as the characteristic estimation value E1 during the working operation of the processing of the workpiece W1. The method of determining the workpiece to be used as the reference may be, for example, a heavy workpiece whose S / N ratio with noise in the friction estimation becomes good due to the large value of the friction force, or a workpiece whose processing is performed in the working operation due to mass production in production. In addition, regarding the operation mode, it may be determined to estimate the characteristic estimation value E1 during the working operation of the operation mode P1 based on the fact that the operation mode is used in large quantities in production and has many opportunities for working operation.

[0037] Therefore, in the upper controller 200, the estimation of the characteristic estimation value E1 is pre-registered and stored in the upper controller in a manner in which the estimation is performed when the type of the workpiece is W1 and the operation mode is P1 as an estimation judgment basis for generating the characteristic estimation indication signal C1. The upper controller determines the type of workpiece and the operation mode according to the production plan as the operating conditions for processing during the working operation, and performs the working operation. Based on the operating conditions such as the determined type of workpiece and the operation mode and the stored estimation judgment basis, a judgment is made as to whether to estimate the characteristic estimation value E1 under the operating conditions of the working operation, and a characteristic estimation indication signal C1 is generated as an instruction to perform the estimation or not to perform the estimation, and is output to the motor drive device 100. Figure 2 As for the characteristic estimation instruction signal C1, when an instruction to perform estimation is given, “estimation” is shown in the diagram, and when an instruction not to perform estimation is shown in the diagram.

[0038] In the motor drive device 100, the drive command signal Xr is received, and a current is passed through the motor 301 so that the drive detection value Xb follows the drive command signal Xr to output a drive torque, thereby driving the drive mechanism 302. At the same time, based on the acquired characteristic estimation instruction signal C1, if the characteristic estimation instruction signal C1 indicates that an estimation is to be performed, an estimation operation is performed in the characteristic estimation unit 111. If the characteristic estimation instruction signal C1 changes from an instruction to perform an estimation to an instruction not to perform an estimation, the value of the characteristic estimation value E1 immediately before the change is saved, and the saved value is output while the characteristic estimation instruction signal C1 indicates that an estimation is not to be performed.

[0039] Therefore, even if the type of workpiece is changed, the operation mode is changed, and the operation conditions are changed, the Figure 2 As shown in the lower part of , the characteristic estimated value E1 of friction and the like is output, and the characteristic estimated value is used without being affected by changes in the operating conditions.

[0040] Therefore, when the characteristic estimation value E1 is displayed and output as an indicator of the time-dependent change of the motor 301 and the drive mechanism 302 during operation, the operator who monitors the drive mechanism 302 can easily grasp the time-dependent change of the characteristics of the drive mechanism 302. In addition, when the setting of the drive control such as the friction compensation is changed in accordance with the change of the characteristics such as the friction caused by the time-dependent change of the motor 301 and the drive mechanism 302 during operation, the setting can be made by grasping the time-dependent change without being affected by the change of the characteristic estimation value E1 caused by the operating conditions.

[0041] That is, the motor drive device 100 according to the present embodiment includes: a drive detection value acquisition unit 103 that acquires a drive detection value Xb obtained based on the position of the motor 301 driven by the motor 301 to drive the drive mechanism 302; a drive command acquisition unit 102 that acquires a drive command signal Xr that is a target value of the drive detection value Xb; a drive control unit 101 that performs a control operation so that the drive detection value Xb follows the drive command signal Xr, and causes a current to flow to the motor 301 to drive the motor 301; and a characteristic estimation instruction acquisition unit 112 that acquires a characteristic estimation instruction signal C from the outside. 1, the characteristic estimation indication signal C1 indicates whether to estimate the characteristic value of the motor 301 or the drive mechanism 302 according to the operating conditions of the driving action determined by the driving command signal Xr; and a characteristic estimation unit, which estimates the characteristic value based on the control state value D1 used in the control operation of the drive control unit 101 when the characteristic estimation indication signal C1 indicates to estimate, and outputs the characteristic estimation value E1, and does not estimate when the characteristic estimation indication signal C1 indicates not to estimate, thereby being able to output the characteristic estimation value without being affected by changes in operating conditions such as changes in the operating mode and changes in the type of workpiece.

[0042] Furthermore, the motor drive system 1 includes the motor drive device 100 and the host controller 200 that outputs the drive command signal Xr and the characteristic estimation instruction signal C1 to the motor drive device 100 , and therefore the estimated value of the characteristic can be used without being affected by changes in the operating conditions.

[0043] Implementation method 2.

[0044] use Figure 1 , Figure 3 The structure of the motor drive device and the motor drive system involved in the second embodiment of the present invention is described. In the first embodiment, an example is shown in which a servo motor is used as the motor 301 and a processing table is used as the drive mechanism 302, but in the second embodiment, the motor 301 is set as an induction motor of a main shaft that rotates a processing tool of a working machine, and the drive mechanism 302 is set as a processing tool of the working machine.

[0045] The detector 400 detects the speed of the motor 301 and outputs it as a drive detection value Xb. The drive control unit 101 controls the speed of the motor 301. The vibration amplitude of the speed deviation obtained by subtracting the drive detection value Xb from the drive command signal Xr is estimated as a characteristic estimation value E1 in the characteristic estimation unit 111, and the characteristic estimation indication signal C1 indicates whether the operation is disturbed. The estimated value of the vibration amplitude of the speed deviation as the characteristic estimation value E1 is not to observe the disturbance torque applied to the rotor of the motor 301 during the cutting process, but to judge whether the rotor of the motor 301 rotates smoothly through the vibration amplitude when the rotor of the motor 301 rotates but the cutting process is not performed, and the time-dependent changes of the bearings and the like supporting the rotor of the motor 301 are monitored.

[0046] More specifically, the drive mechanism 302 is, for example, a machining tool such as an end mill that performs cutting inside a machine tool. The motor 301 is, for example, an induction motor, and the machining tool is mechanically mounted to the rotation output shaft of the rotor of the motor 301 via a tool chuck as the drive mechanism 302 and driven.

[0047] The detector 400 is configured, for example, to be able to detect the speed of the driven motor 301 and output the detected speed as a drive detection value Xb to the motor drive device 100 .

[0048] The drive detection value acquisition unit 103 acquires the speed of the motor 301 from the detector 400 as the drive detection value Xb. The drive command acquisition unit 102 acquires the target value for the speed of the motor 301 from the upper controller 200 as the drive command signal Xr. The drive control unit 101 performs control calculation based on the drive command signal Xr and the drive detection value Xb, applies voltage to the motor 301 to flow the current Im, and causes the motor 301 to generate a drive torque, so that the drive detection value Xb follows the drive command signal Xr. The drive control unit 101 outputs the control state value D1 to the characteristic estimation unit 111. The control state value D1 includes, for example, a speed deviation calculated by the drive control unit 101 for the control calculation, which is obtained by subtracting the drive detection value Xb, which is the speed detection value of the motor 301, from the drive command signal Xr, which is the target value for the speed of the motor 301. For example, the motor 301 is controlled in a manner that follows the target value of the speed that is a constant value, and the speed deviation is smooth if there is no problem with the bearing or the like. Here, for example, if the ball bearing supporting the rotor of the motor 301 is damaged, a periodic external force is generated relative to the rotation of the motor 301, and a vibration of speed deviation occurs. However, during the cutting process, the speed deviation generates vibration due to the periodic interference torque when the machining tool cuts the workpiece.

[0049] The characteristic estimation unit 111 obtains the control state value D1 from the drive control unit 101, and outputs the characteristic estimation value E1 in accordance with the characteristic estimation instruction signal C1 obtained from the upper controller 200. The characteristic estimation instruction signal C1 is a signal indicating whether to perform an estimation operation. When the characteristic estimation instruction signal C1 indicates that the estimation is to be performed, the characteristic estimation unit 111 estimates the characteristics of the drive unit 300 based on the control state value D1 obtained from the drive control unit 101, and outputs the estimated value as the characteristic estimation value E1. When the characteristic estimation instruction signal C1 indicates that the estimation is not to be performed, the characteristic estimation unit 111 does not estimate the characteristic estimation value E1. As a method for estimating the characteristic estimation value E1 based on the control state value D1, for example, a high-pass filter is used to remove low-frequency components such as offset from the speed deviation obtained as the control state value D1 to extract the vibration component, and the absolute value of the vibration component is averaged to thereby set it as a vibration amplitude estimation value for estimating the amplitude of the vibration, and the vibration amplitude estimation value is output as the characteristic estimation value E1.

[0050] Figure 3 This is an example of a situation in which the vibration amplitude estimation value of the speed deviation of the motor 301 that rotates the machining tool is estimated as the characteristic estimation value E1 during the operation in which the motor 301 drives the machining tool as the driving mechanism 302. For comparison, the situation in which the vibration amplitude of the speed deviation is always estimated is shown in FIG. Figure 3 The estimated value of the vibration amplitude is shown. Figure 3 For periods 521, 523, and 525, the movement command of the worktable on which the workpiece is placed is the positioning command G00. Periods 522 and 524 are the cutting movement commands G01. In periods 522 and 524, the vibration amplitude of the speed deviation increases due to the influence of the interference of the cutting external force when the machining tool cuts the workpiece during operation.

[0051] For example, if the estimated value of the constant vibration amplitude of the speed deviation is displayed and output as an indicator of the time-dependent change of the bearing that supports and rotates the rotor of the motor 301 on which the machining tool is mounted, the displayed output value of the estimated value of the constant vibration amplitude changes greatly due to the change of the operating conditions such as the implementation of the operation that generates interference with the cutting process as described above. If the operator who monitors the driving mechanism 302 refers to the estimated value of the constant vibration amplitude of the speed deviation including the change in order to understand the characteristics of the driving mechanism 302 due to the time-dependent change, it is difficult to understand the characteristics of the driving mechanism 302 due to the influence of the operating conditions such as the implementation of the operation that generates interference.

[0052] Therefore, the characteristic estimation value E1 is output as described below. Since the upper-level controller 200 stores the operation program, it can be known from the description of the movement command in the operation program whether the movement command to be performed next is a cutting movement accompanied by cutting or a positioning movement without cutting. Therefore, for example, in the upper-level controller 200, when the movement command of the machining table in the operation program is a positioning movement G00, the characteristic estimation indication signal C1 is set to an indication for estimation, and when it is a cutting movement G01 with interference caused by external cutting force, the characteristic estimation indication signal C1 is set to an indication for not estimating. In this way, the determined characteristic estimation indication signal C1 is output from the upper-level controller 200 to the motor drive device 100. Figure 3 As for the characteristic estimation instruction signal C1, when an instruction to perform estimation is given, “estimation” is shown in the diagram, and when an instruction not to perform estimation is shown in the diagram.

[0053] In the motor drive device 100, the drive command signal Xr is received, and a current is caused to flow through the motor 301 so that the drive detection value Xb follows the drive command signal Xr to output a drive torque, thereby driving the drive mechanism 302. In parallel, based on the acquired characteristic estimation instruction signal C1, if the characteristic estimation instruction signal C1 indicates that estimation is to be performed, estimation is performed in the characteristic estimation unit 111. If the characteristic estimation instruction signal C1 changes from an instruction to perform estimation to an instruction not to perform estimation, for example, the value of the characteristic estimation value E1 immediately before the change is saved, and the saved value is output while the characteristic estimation instruction signal C1 indicates that estimation is not to be performed.

[0054] Therefore, even when the operation is performed with disturbance, the characteristic estimation value E1 does not change significantly. Figure 3 The characteristic estimated value E1 is output as shown, and even in the case of a change in operating conditions such as an operation with interference, the characteristic estimated value can be used without being affected by the operating conditions. Therefore, when the characteristic estimated value E1 is displayed and output as an indicator of the aging change of the motor 301 or the drive mechanism 302 during operation, it is easy for the operator who monitors the drive mechanism 302 to grasp the aging change of the characteristics of the drive mechanism 302. In addition, when the setting of the vibration suppression function is changed in accordance with the change in the vibration amplitude of the motor 301 and the drive mechanism 302 caused by the aging change during operation, it is also possible to grasp the aging change and make settings without being affected by the change in the characteristic estimated value E1.

[0055] Therefore, in the motor drive device 100 and the motor drive system 1 according to the present embodiment, similarly to the first embodiment, estimated values ​​of characteristics can be output and used without being affected by changes in operating conditions such as the execution of an operation with disturbance.

[0056] Implementation method 3.

[0057] A motor drive device and a motor drive system according to a third embodiment of the present invention will be described. Figure 4 FIG. 2 is a schematic diagram showing a motor drive system according to a third embodiment of the present invention. Figure 4 In the Figure 1 The same reference numerals indicate the same or corresponding structures, and their description is omitted. The difference from Embodiment 1 is that the motor drive device 100 has the abnormality diagnosis instruction acquisition unit 122 and the abnormality diagnosis unit 121, but does not have the characteristic estimation instruction acquisition unit 112, and the characteristic estimation unit 111 always outputs the characteristic estimation value E0.

[0058] The characteristic estimation unit 111 acquires the control state value D1 from the drive control unit 101 , estimates the characteristic value of the drive unit 300 based on the control state value D1 , and outputs the estimated value as the constant characteristic estimated value E0 regardless of the operating conditions.

[0059] The abnormality diagnosis instruction acquisition unit 122 acquires the abnormality diagnosis instruction signal C2 from the host controller 200 outside the motor drive device 100 .

[0060] The abnormality diagnosis unit 121 obtains the constant characteristic estimated value E0 from the characteristic estimation unit 111, performs abnormality diagnosis corresponding to the abnormality diagnosis indication signal C2 obtained from the external upper controller 200, and outputs the abnormality determination signal F1 as the result of the abnormality diagnosis. When the abnormality diagnosis indication signal C2 is an indication for diagnosis, the abnormality diagnosis unit 121 performs abnormality diagnosis of the drive unit 300 based on the constant characteristic estimated value E0 obtained from the characteristic estimation unit 111. As the determination process of abnormality diagnosis, for example, it is determined whether the constant characteristic estimated value E0 falls within the preset allowable range of the constant characteristic estimated value E0. As the allowable range, in the initial stage of starting the drive mechanism 302, for example, an upper limit of the allowable range and a lower limit of the allowable range are set for the average constant characteristic estimated value E0 with a certain allowable range width. If the abnormality diagnosis indication signal C2 is an indication for diagnosis, the abnormality diagnosis unit 121 performs abnormality diagnosis, and when the constant characteristic estimated value E0 exceeds the allowable range, it is determined as abnormal, and the abnormality determination signal F1 is output as abnormal. When the characteristic estimation value E0 is always within the allowable range, it is determined that it is not abnormal, and the abnormality determination signal F1 is output as normal. If the abnormality diagnosis indication signal C2 is an indication not to perform diagnosis, the abnormality diagnosis unit 121 does not perform abnormality diagnosis based on the characteristic estimation value E0, and outputs the abnormality determination signal F1 as normal. The abnormality determination signal F1 is output to a display of the motor drive device 100, for example, and the detected abnormality is displayed on the display as a warning. The operator who monitors the motor drive device 100 can know that the characteristic estimation value E0 is always judged to be abnormal by observing the display.

[0061] Figure 5 The following example is an example of a working operation of a processing table that carries a workpiece and moves via a ball screw, in which a driving mechanism 302 driven by a motor 301 is used. The friction of the ball screw of the processing table is estimated as a constant characteristic estimated value E0, and the abnormality diagnosis based on the estimated constant characteristic estimated value E0 is shown in a time series. Figure 5In the embodiment, the characteristic estimation value E0 is represented by the friction estimation value obtained by estimating the friction. For example, in period 531, the workpiece W1 is operated, in period 532, the type of the workpiece is changed to workpiece W2 whose load is lighter than that of the workpiece W1, and in periods 533, 534, and 535, the type of the workpiece is changed again and the workpiece W1 is operated. Regarding the operation mode, in periods 531, 532, and 533, the operation mode P1 is used for operation, and in period 534, the operation mode is changed to operation mode P2 whose interval time from processing a certain workpiece to processing the next workpiece is longer than that of operation mode P1, and the operation is performed. In period 535, the operation mode P1 is returned to for operation.

[0062] During period 532, since the type of workpiece is changed to W2 and the load becomes lighter, the friction at the ball screw carrying the workpiece becomes smaller, and the constant friction estimated value as the constant characteristic estimated value E0 changes to a value smaller than that during period 531 and smaller than the lower limit of the allowable range.

[0063] During period 534, since the processing of the workpiece and the interval time between processing become longer, the heat dissipation of the ball screw during the interval time becomes larger, so the temperature of the ball screw is lower than that during period 533. Due to the decrease in temperature, the friction becomes larger, and the constant friction estimation value as the constant characteristic estimation value E0 is larger than that during period 533 and larger than the upper limit of the allowable range.

[0064] Furthermore, from the period 533 to the period 535 , the friction gradually increases due to the aging change regardless of the operating conditions, and at a point in the middle of the period 535 , the constant friction estimated value, which is the constant characteristic estimated value E0 , exceeds the upper limit of the allowable range.

[0065] For example, in a case where an abnormality diagnosis is always performed based on the constant friction estimation value as the constant characteristic estimation value E0, the constant friction estimation value deviates from the allowable range during the period 532 or the period 534 when the constant friction estimation value greatly changes due to changes in operating conditions such as changes in the type of workpiece and changes in the operating mode as described above, and an abnormality is erroneously detected in the abnormality diagnosis.

[0066] Therefore, for example, as a reference for performing abnormality diagnosis due to a time-dependent change in friction, abnormality diagnosis is performed in the workpiece type W1 and in the operation mode P1.

[0067] For example, as a reference for abnormal diagnosis implementation, the content of performing abnormal diagnosis when the type of workpiece is W1 and the operation mode is P1 is pre-registered and stored in the upper controller 200. The upper controller 200 performs the operation by outputting the drive command signal Xr to the motor drive device 100 based on the type of workpiece and the operation mode determined as the operation conditions for the operation based on the production plan. In addition, the upper controller 200 generates the abnormal diagnosis indication signal C2 as an indication to perform diagnosis or not to perform diagnosis based on the operation conditions such as the type of workpiece and the operation mode to be operated and the pre-registered and stored abnormal diagnosis implementation reference, and outputs it to the motor drive device 100. Figure 5 As for the abnormal diagnosis instruction signal C2, "diagnosis" is shown in the figure when an instruction to perform a diagnosis is given, and "interruption" is shown in the figure when an instruction not to perform a diagnosis is given.

[0068] In the motor drive device 100, the drive command signal Xr is received, and the current flows through the motor 301 so that the drive detection value Xb follows the drive command signal Xr to output the drive torque, thereby driving the drive mechanism 302. In addition, the characteristic estimation unit 111 obtains the control state value D1 from the drive control unit 101, estimates the characteristics of the drive unit 300 based on the control state value D1, and outputs the value obtained by the estimation regardless of the operating conditions as the constant characteristic estimation value E0. The abnormal diagnosis instruction acquisition unit 122 obtains the abnormal diagnosis instruction signal C2 from the external upper controller 200.

[0069] The abnormality diagnosis unit 121 obtains the abnormality diagnosis indication signal C2 from the abnormality diagnosis indication acquisition unit 122. When the abnormality diagnosis indication signal C2 indicates that a diagnosis is to be performed, the abnormality diagnosis unit 121 obtains the constant characteristic estimation value E0 from the characteristic estimation unit 111, performs abnormality diagnosis based on the constant characteristic estimation value E0, and outputs the abnormality determination signal F1 as an abnormality determination result when an abnormality is detected. When no abnormality is detected, the abnormality determination signal F1 is output as a normal determination result. In addition, when the abnormality diagnosis indication signal C2 indicates that no diagnosis is to be performed, the abnormality diagnosis is interrupted, and the abnormality determination signal F1 is output as a normal determination result. Figure 5 As for the abnormality determination signal F1, "abnormal" is shown in the diagram in the case of an abnormal diagnosis result, and "normal" is shown in the diagram in the case of a normal determination result.

[0070] exist Figure 5During the period 531, since the type of workpiece is W1 and the operation mode is P1, the abnormal diagnosis indication signal C2 is set as an indication for diagnosis. Since the abnormal diagnosis indication signal C2 is an indication for diagnosis, abnormal diagnosis is performed by the abnormal diagnosis unit 121. However, since the constant friction estimation value which is the constant characteristic estimation value E0 falls within the allowable range, the abnormal judgment signal F1 is output as a normal judgment result.

[0071] During period 532, the type of workpiece is changed to W2, and the constant friction estimation value as the constant characteristic estimation value E0 is a value smaller than the lower limit of the allowable range. However, since the type of workpiece is W2, the abnormal diagnosis indication signal C2 is set to an indication not to perform diagnosis. Since the abnormal diagnosis indication signal C2 is an indication not to perform diagnosis, the abnormal diagnosis unit 121 does not perform abnormal diagnosis, and the abnormal judgment signal F1 is output as a normal judgment result.

[0072] The period 533 is the same operation as the period 531 , and the abnormality determination signal F1 is output as a normal determination result.

[0073] During period 534, the operation mode is changed to P2, and the constant friction estimation value, which is the constant characteristic estimation value E0, is a value larger than the upper limit of the allowable range. However, since the operation mode is P2, the abnormal diagnosis indication signal C2 is set to an indication not to perform diagnosis. Since the abnormal diagnosis indication signal C2 is an indication not to perform diagnosis, the abnormal diagnosis unit 121 does not perform abnormal diagnosis, and the abnormal judgment signal F1 is output as a normal judgment result.

[0074] During period 535, since the type of workpiece is W1 and the operation mode is P1, the abnormal diagnosis indication signal C2 is set as an indication for diagnosis. Since the abnormal diagnosis indication signal C2 is an indication for diagnosis, abnormal diagnosis is performed by the abnormal diagnosis unit 121. If the constant friction estimation value, which is the constant characteristic estimation value E0, increases due to aging changes and becomes larger than the upper limit of the allowable range during period 535, an abnormality is detected and the abnormal judgment signal F1 outputs the abnormal judgment result.

[0075] In this way, even if there is a change in the type of workpiece, a change in the operating mode, or other operating conditions, and the constant characteristic estimation value E0 of friction or the like changes and is output in conjunction with the change in the operating conditions, an abnormal diagnosis indication signal C2 indicating whether to perform abnormal diagnosis according to the operating conditions is obtained from the outside. When the abnormal diagnosis indication signal C2 indicates that a diagnosis is to be performed, the constant characteristic estimation value E0 is obtained from the characteristic estimation unit 111, abnormal diagnosis is performed and an abnormal determination signal C2 is output. When the abnormal diagnosis indication signal F1 indicates that a diagnosis is not to be performed, abnormal diagnosis is not performed. Therefore, abnormal conditions can be truly diagnosed based on characteristic estimation values ​​that are not affected by the change in operating conditions. Therefore, false detection of abnormal diagnosis can be reduced, and highly reliable abnormal diagnosis can be performed.

[0076] That is, the motor drive device 100 and the motor drive system 1 involved in the present embodiment include: a drive detection value acquisition unit 103, which acquires a drive detection value Xb based on the position of the motor 301 driven by the motor 301 to drive the drive mechanism 302; a drive command acquisition unit 102, which acquires a drive command signal Xr that becomes a target value of the drive detection value Xb; a drive control unit 101, which performs a control operation in a manner such that the drive detection value Xb follows the drive command signal Xr, so that the current Im flows to the motor 301 and the motor 301 performs a driving action; and a characteristic estimation unit 111, which acquires a control state value D1 used in the control operation from the drive control unit 101, and performs an estimation of the characteristic value of the motor 301 or the drive mechanism 302. The control unit 110 includes an abnormal diagnosis instruction acquisition unit 122, which acquires an abnormal diagnosis instruction signal C2 from the outside, and the abnormal diagnosis instruction signal C2 indicates whether to perform abnormal diagnosis based on the constant characteristic estimation value E0 according to the operating conditions of the driving action determined by the driving command signal Xr; and an abnormal diagnosis unit 121, which performs abnormal diagnosis based on the constant characteristic estimation value E0 of the characteristic estimation unit 111 and outputs an abnormal determination signal F1 when the abnormal diagnosis instruction signal C2 is an indication to perform diagnosis, and does not perform abnormal diagnosis when the abnormal diagnosis instruction signal C2 is an indication not to perform diagnosis, thereby enabling abnormal diagnosis based on characteristic estimation to be performed without being affected by changes in operating conditions such as changes in the operating mode and changes in the type of workpiece.

[0077] Moreover, the characteristic estimation unit 111 estimates the constant characteristic estimation value E0 regardless of the operating conditions, and the abnormality diagnosis unit 121 that obtains the constant characteristic estimation value E0 is not affected by the change of the operating conditions. Therefore, in other functional uses that want to refer to and use the constant characteristic estimation value E0 including the change caused by the change of the operating conditions, the constant characteristic estimation value E0 can also be referred to and used. In addition, when there are a plurality of abnormality diagnosis units 121 that perform abnormality diagnosis under different operating conditions, since each abnormality diagnosis unit 121 can refer to and obtain one constant characteristic estimation value E0 to perform abnormality diagnosis, the processing of the characteristic estimation unit 111 can be made common, can be implemented with a small processing load, and can also reduce the man-hours for processing development.

[0078] In addition, the abnormality determination signal F1 is described with two values, namely, an abnormality determination result indicating that an abnormality is detected and a normal determination result indicating that no abnormality is detected, but it may also be a signal indicating the remaining life obtained by estimating the remaining time until the drive unit 300 becomes unable to drive and operate due to aging changes. In the case of such a signal, the estimated value of the characteristic can be used without being affected by changes in operating conditions such as changes in the type of workpiece and changes in the operating mode, and highly reliable abnormality diagnosis can be performed. Moreover, by outputting a signal indicating the remaining life with a display not shown, the operator who monitors the drive unit 300 can refer to it, so that the operator can predict a highly reliable maintenance period.

[0079] Implementation method 4.

[0080] Figure 6 FIG. 4 is a schematic diagram showing a motor drive system according to a fourth embodiment of the present invention. Figure 6 In the Figure 1 The same reference numerals indicate the same or corresponding structures, and their descriptions are omitted. The difference from the first embodiment of the present invention is that the motor drive device 100 has an abnormality diagnosis unit 121, an abnormality reference creation unit 131, and an abnormality reference creation instruction acquisition unit 132, and the abnormality reference creation instruction acquisition unit 132 acquires the abnormality reference creation instruction signal C3 from the upper controller outside the motor drive device 100.

[0081] The abnormality diagnosis unit 121 acquires the characteristic estimated value E1 from the characteristic estimation unit 111 , performs abnormality diagnosis, and outputs an abnormality determination signal F1 as a result of the abnormality diagnosis.

[0082] The abnormality reference creation instruction acquisition unit 132 acquires the abnormality reference creation instruction signal C3 from the host controller 200 outside the motor drive device 100 .

[0083] The abnormality reference creation unit 131 obtains the characteristic estimation value E1 from the characteristic estimation unit 111, determines whether to use the characteristic estimation value E1 for abnormality reference creation processing based on the abnormality reference creation instruction signal C3 obtained from the external upper controller 200, and creates the abnormality diagnosis reference H1. The created abnormality diagnosis reference H1 is output to the abnormality diagnosis unit 121.

[0084] The process of creating the abnormal diagnosis benchmark H1 by the abnormal benchmark creation unit 131 is performed, for example, as follows. It is predetermined how long a period of characteristic estimation value E1 is used to create the abnormal diagnosis benchmark H1, which is set as the benchmark creation period. The abnormal benchmark creation unit 131 obtains the characteristic estimation value E1 during the benchmark creation period and stores it, and calculates the average value and standard deviation based on the stored characteristic estimation value E1. In addition, the abnormal diagnosis unit 121 predetermines the specification of the occurrence probability of abnormal detection as the occurrence probability, and calculates the benchmark coefficient through the standard normal distribution based on the occurrence probability. Based on the calculated average value, standard deviation and benchmark coefficient of the characteristic estimation value E1, for example, the upper and lower limits of the allowable range are created as the abnormal diagnosis benchmark H1 by using the average value ± standard deviation × benchmark coefficient. When acquiring and storing the characteristic estimation value E1 during the reference creation period in order to calculate the average value and the standard deviation, the characteristic estimation value E1 is stored when the abnormal reference creation instruction signal C3 acquired from the external upper controller 200 is an instruction for creation, and is not stored when the abnormal reference creation instruction signal C3 is an instruction not for creation. The characteristic estimation value E1 is stored until the abnormal reference creation instruction signal C3 is an instruction for creation and the total number of stored times or time becomes the reference creation period. Regarding the storage of the characteristic estimation value E1, for example, by storing it in a non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory) or a flash memory that can be used by the abnormality benchmark creation unit 131, when the power supply of the motor drive device 100 is cut off at the end of one day's operation, and the power supply of the motor drive device 100 is turned on again the next day to restart the operation, the abnormality diagnosis benchmark H1 can be created using the characteristic estimation value E1 during the benchmark creation period of several days spanning the time when the power supply of the motor drive device 100 was cut off.

[0085] For actions, use Figure 7An example of creating an abnormal diagnosis benchmark H1 in a motor drive device 100 is described. The motor drive device 100 is configured to estimate the friction of the ball screw of the drive mechanism 302, i.e., the processing table of the working machine, as a characteristic estimated value E1. In addition to the time-related changes, changes in friction caused by changes in the type of workpiece are also judged to be abnormal if the changes are large.

[0086] exist Figure 7 In terms of the type of workpiece, work is performed on workpieces W3, W4, and W5 during periods 543, 548, and 552, respectively, and work is performed on workpiece W1 during other periods. In terms of the operation mode, work is performed in operation mode P2 during periods 545 and 550, and in operation mode P1 otherwise. The characteristic estimation indication signal C1 does not change even if the type of workpiece changes, and is set to indicate that estimation is to be performed when the operation mode is P1, and is set to indicate that no estimation is to be performed when the operation mode is P2. Figure 7 As for the characteristic estimation indication signal C1, "estimation" is shown in the diagram when an indication is given to perform estimation, and "interruption" is shown in the diagram when an indication is given not to perform estimation. Based on the characteristic estimation indication signal C1, in the characteristic estimation unit 111, even if the type of the workpiece changes, the friction estimation value is estimated and output as the characteristic estimation value E1. When the operation mode is changed to P2, no estimation is performed, and the friction characteristic estimation value as the characteristic estimation value E1 just before the estimation is not performed is saved and output. As a result, in the abnormality diagnosis unit 121, regarding the change in the type of the workpiece, when the change in the friction estimation value as the characteristic estimation value E1 deviates from the allowable range, it is detected as an abnormality. Regarding the change in the operation mode, the characteristic estimation value E1 is outputted excluding the change caused by the change in the operation mode, and the erroneous detection of the abnormality caused by the change is not performed.

[0087] It is assumed that in the middle of such operation, for example, a drive mechanism component such as a sliding rubber bushing of a ball screw of a processing table is replaced by maintenance of the drive mechanism between periods 541 and 542. Since there are individual differences in the friction of the replaced sliding rubber bushing, a reference for abnormality diagnosis is created while the operation is continued after the component replacement.

[0088] The abnormal reference creation unit 131 acquires and stores the characteristic estimated value E1 in accordance with the instruction of the abnormal reference creation instruction signal C3, and creates the abnormality diagnosis reference H1 based on the stored characteristic estimated value E1 when the total of the stored period reaches a predetermined reference creation period.

[0089] Here, in the upper controller 200, the type of workpiece used in the working operation and the operation mode are known, and when the type of workpiece is W1 and the operation mode is P1, the abnormal reference creation indication signal C3 is set as an indication for creation. Figure 7 In the example of workpiece W3 and operation mode P2), it is set as an instruction not to be used for creation. After the total of the stored periods reaches the base creation period (in Figure 7 In the example, the period 547 and thereafter is set as an instruction not to be used for creation regardless of the operating conditions. Figure 7 As for the abnormal reference creation instruction signal C3, "create" is illustrated in the case of an instruction for creation, and "interrupt" is illustrated in the case of an instruction not for creation.

[0090] The abnormal reference creation instruction signal C3 is acquired from the upper controller 200 outside the motor drive device 100 by the abnormal reference creation instruction acquisition unit 132 of the motor drive device 100. In the abnormal reference creation unit 131, the characteristic estimation value E1 is stored when the abnormal reference creation instruction signal C3 is an instruction for creation, and is not stored when it is not an instruction for creation. The characteristic estimation value E1 is stored until the abnormal reference creation instruction signal C3 is an instruction for creation and the total number of stored times or time becomes the reference creation period.

[0091] exist Figure 7 In the process, as for periods 542, 544, and 546, since the type of workpiece is W1 and the operation mode is P1, the abnormal reference creation indication signal C3 is set as an indication for creation, and the characteristic estimation value E1 is stored during this period. Since the total time of periods 542, 544, and 546 becomes the reference creation period, the storage is completed at the end of period 546, and then the abnormal reference creation indication signal C3 is also changed to an indication not used for creation. In the abnormal reference creation unit 131, after the average value and the standard deviation are calculated based on the stored characteristic estimation value E1, the upper and lower limits of the allowable range are calculated as the abnormal diagnosis reference H1, and output to the abnormal diagnosis unit 121. That is, in Figure 7 In the period 547 and thereafter, abnormality diagnosis is performed based on the abnormality diagnosis reference H1, and the result of the abnormality diagnosis is output as the abnormality determination signal F1.

[0092] In this way, since a highly reliable abnormality diagnosis reference H1 based on characteristic estimation is created without being affected by changes in operating conditions such as changes in workpiece type and operating mode, and abnormality diagnosis is performed based on the abnormality diagnosis reference H1, highly reliable abnormality diagnosis can be performed.

[0093] That is, the motor drive device 100 of embodiments 1 to 3 has: an abnormal reference creation instruction acquisition unit 132, which acquires an abnormal reference creation instruction signal C3 from the outside, and the abnormal reference creation instruction signal C3 indicates whether to use the characteristic estimation value E1 for the creation of an abnormal diagnosis reference H1 for abnormal diagnosis according to the operating conditions of the driving action determined by the driving instruction signal Xr; and an abnormal reference creation unit 131, which acquires the characteristic estimation value E1 from the characteristic estimation unit 111 when the abnormal reference creation instruction signal C3 is an instruction for creation, and does not acquire the characteristic estimation value E1 output by the characteristic estimation unit 111 when the abnormal reference creation instruction signal C3 is an instruction not for creation. The abnormal reference creation unit 131 creates the abnormal diagnosis reference H1 for abnormal diagnosis based on the acquired characteristic estimation value E1 and outputs it to the abnormal diagnosis unit 121, thereby being able to create the abnormal diagnosis reference H1 with high reliability based on the characteristic estimation without being affected by changes in operating conditions such as changes in the operating mode and changes in the type of workpiece, and perform highly reliable abnormal diagnosis.

[0094] Furthermore, since the abnormal diagnosis reference H1 is created by the abnormal reference creation unit 131, the operator does not need to perform measurement work to set the abnormal diagnosis reference H1, which saves the operator's work hours. In addition, after the replacement of parts by maintenance of the drive unit 300, it is not necessary to stop the operation of the drive unit 300 to perform measurement work in order to reset the abnormal diagnosis reference H1, which can improve the productivity of the drive unit 300.

[0095] In addition, an example is described in which after the characteristic estimation value E1 is stored by the abnormality reference creation unit 131, the abnormality diagnosis reference H1 is created using the stored characteristic estimation value E1, but it is also possible to create the abnormality diagnosis reference H1 by sequentially updating and calculating the abnormality diagnosis reference H1 based on the characteristic estimation value E1 without storing the characteristic estimation value E1 when the abnormality reference creation instruction signal C3 is an instruction for creation. In addition, an example is described in which the abnormality diagnosis reference H1 is created using the average value, standard deviation, probability of occurrence of abnormality detection, and normal distribution of the characteristic estimation value E1, but it is also possible to create the abnormality diagnosis reference H1 based on the maximum and minimum values ​​of the characteristic estimation value E1 in a certain period.

[0096] In this way, when the abnormal diagnosis benchmark H1 is created, the abnormal diagnosis benchmark H1 with high reliability based on characteristic estimation is created without being affected by changes in operating conditions such as changes in operating mode and changes in the type of workpiece, and abnormal diagnosis is performed based on the abnormal diagnosis benchmark H1, thereby enabling abnormal diagnosis with high reliability.

[0097] In addition, in embodiments 1 to 4, the drive mechanism 302 is described as an example of a processing worktable that linearly drives the worktable through a ball screw or a processing tool held by a tool chuck, but it can also be a rotational drive mechanism that drives a gear mechanism combined with spur gears, etc. to rotate, a belt drive mechanism of a rotating shaft separated by a belt and a pulley, etc.

[0098] Furthermore, although the example in which the driving unit 300 includes the motor 301 and the driving mechanism 302 has been described, the driving unit 300 may include only the motor 301 .

[0099] Although the motor 301 is described as a servo motor or an induction motor, it may be a reluctance motor, a linear motor that is not a rotary motor, or the like.

[0100] The example in which the detector 400 detects the position or speed of the motor 301 is described, but the position or speed of the drive mechanism 302 may be detected. Alternatively, the detector 400 may be replaced by detecting the position or speed of the motor 301 based on the current of the motor 301 in the motor drive device 100.

[0101] The characteristic estimation value E1 is described using the example of the friction characteristic estimation value based on friction or the vibration amplitude characteristic estimation value based on speed deviation, but it can also be an estimation value of the vibration amplitude or vibration frequency of any one of the position, speed, and current. It can also be an estimation value of the inertia moment value of the motor 301 and the drive mechanism 302. That is, the characteristic estimation value E1 can use at least any one of the Coulomb friction, viscous friction, moment of inertia of the motor 301, the vibration amplitude of the position of the motor 301, the vibration frequency of the position, the vibration amplitude of the speed of the motor 301, the vibration frequency of the speed, the vibration amplitude of the current of the motor 301, the vibration frequency of the current, the vibration amplitude of the torque of the motor 301, the vibration frequency of the torque, and the Coulomb friction, viscous friction, and moment of inertia of the drive mechanism 302.

[0102] In addition, an example is described in which the characteristic estimation indication signal C1, the abnormality diagnosis indication signal C2, or the abnormality reference creation signal C3 is output from the external upper controller 200 to the motor drive device 100, but it is also possible to obtain a signal based on a change in operating conditions such as a change in the type of workpiece from an external workpiece supply device, and output the characteristic estimation indication signal C1 from the workpiece supply device to the motor drive device 100. In addition, the characteristic estimation indication signal C1, the abnormality diagnosis indication signal C2, or the abnormality reference creation signal C3 may be passed through other devices.

[0103] The operation with interference is described by using the operation in which interference is caused by the cutting force during processing due to a cutting movement command in a working machine, but it can also be the operation in which interference is caused by the impact force when loading the conveying object due to a command to load the conveying drive mechanism on the conveying drive mechanism, and the operation in which interference is caused by the gravity of the heavy object being held during the holding of a heavy object by a command to give a holding instruction in a robot.

[0104] Furthermore, the present invention can freely combine the various embodiments within the scope of the invention, and can appropriately modify or omit the various embodiments.

[0105] Description of the label

[0106] 1 Motor drive system, 100 Motor drive device, 101 Drive control unit, 102 Drive instruction acquisition unit, 103 Drive detection value acquisition unit, 104 Current detection unit, 111 Characteristic estimation unit, 112 Characteristic estimation indication acquisition unit, 121 Abnormality diagnosis unit, 122 Abnormality diagnosis indication acquisition unit, 131 Abnormality reference creation unit, 132 Abnormality reference creation indication acquisition unit, 200 Superior controller, 300 Drive unit, 301 Motor, 302 Drive mechanism, 400 Detector.

Claims

1. A motor drive device, comprising: a drive detection value acquisition unit that acquires a drive detection value based on the position or speed of the motor that drives the drive mechanism through the motor; a drive instruction acquisition unit that acquires a drive instruction signal that becomes a target value of the drive detection value; a drive control unit that performs control calculation so that the drive detection value follows the drive command signal, and causes current to flow to the motor to drive the motor; a characteristic estimation instruction acquisition unit that acquires a characteristic estimation instruction signal from outside, the characteristic estimation instruction signal indicating a first instruction to estimate a characteristic value of the motor or the drive mechanism or a second instruction not to estimate the characteristic value according to an operation condition of the drive action determined by the drive command signal; a characteristic estimating unit that estimates the characteristic value based on a control state value used in the control calculation of the drive control unit and outputs the characteristic estimated value when the characteristic estimation instruction signal is a first instruction, and does not estimate when the characteristic estimation instruction signal is a second instruction; an abnormality diagnosis unit that performs abnormality diagnosis of the motor or the drive mechanism based on the characteristic estimation value and outputs an abnormality determination signal; an abnormality reference creation instruction acquisition unit that acquires an abnormality reference creation instruction signal from outside, the abnormality reference creation instruction signal indicating a fifth instruction to use the characteristic estimation value for creation of an abnormality diagnosis reference for the abnormality diagnosis or a sixth instruction not to use the characteristic estimation value, based on an operating condition of the drive action determined by the drive command signal; as well as An abnormal benchmark creation unit, which obtains the characteristic estimation value from the characteristic estimation unit when the abnormal benchmark creation indication signal is the fifth indication, and does not obtain the characteristic estimation value output by the characteristic estimation unit when the abnormal benchmark creation indication signal is the sixth indication, and creates the abnormal diagnosis benchmark of the abnormal diagnosis based on the obtained characteristic estimation value and outputs it to the abnormal diagnosis unit.

2. The motor drive device according to claim 1, characterized in that: The characteristic estimating unit stores or outputs, as the characteristic estimated value, the characteristic estimated value before the instruction not to perform estimation is given, or outputs a predetermined value when the characteristic estimation instruction signal is the second instruction.

3. The motor drive device according to claim 1 or 2, characterized in that: The characteristic estimation value is obtained by estimating at least any one of the following: Coulomb friction, viscous friction and moment of inertia of the motor; an amplitude of vibration at said location of said motor and a frequency of vibration at said location; a vibration amplitude of said speed and a vibration frequency of said speed of said motor; a vibration amplitude of the electric current of the electric motor and a vibration frequency of the electric current; a vibration amplitude of the torque of the motor and a vibration frequency of the torque; and Coulomb friction, viscous friction and moment of inertia of the drive mechanism.

4. The motor drive device according to claim 1 or 2, characterized in that: The driving instruction signal is the driving instruction signal in working operation.

5. The motor drive device according to claim 1 or 2, characterized in that: The operating condition includes at least any one of an operating mode, a type of workpiece, and an operation with interference.

6. A motor drive device, comprising: a drive detection value acquisition unit that acquires a drive detection value based on the position or speed of the motor that drives the drive mechanism through the motor; a drive instruction acquisition unit that acquires a drive instruction signal that becomes a target value of the drive detection value; a drive control unit that performs control calculation so that the drive detection value follows the drive command signal, and causes current to flow to the motor to drive the motor; a characteristic estimating unit that acquires a control state value used in the control calculation from the drive control unit, estimates a characteristic value of the motor or the drive mechanism, and outputs a characteristic estimation value; an abnormality diagnosis instruction acquisition unit that acquires an abnormality diagnosis instruction signal from the outside, the abnormality diagnosis instruction signal indicating a third instruction to perform abnormality diagnosis based on the characteristic estimation value or a fourth instruction not to perform abnormality diagnosis according to an operating condition of the drive action determined by the drive command signal; an abnormality diagnosis unit that performs the abnormality diagnosis based on the characteristic estimation value of the characteristic estimation unit and outputs an abnormality determination signal when the abnormality diagnosis indication signal is a third indication, and does not perform the abnormality diagnosis when the abnormality diagnosis indication signal is a fourth indication; an abnormality reference creation instruction acquisition unit that acquires an abnormality reference creation instruction signal from outside, the abnormality reference creation instruction signal indicating a fifth instruction to use the characteristic estimation value for creation of an abnormality diagnosis reference for the abnormality diagnosis or a sixth instruction not to use the characteristic estimation value, based on an operating condition of the drive action determined by the drive command signal; as well as An abnormal benchmark creation unit, which obtains the characteristic estimation value from the characteristic estimation unit when the abnormal benchmark creation indication signal is the fifth indication, and does not obtain the characteristic estimation value output by the characteristic estimation unit when the abnormal benchmark creation indication signal is the sixth indication, and creates the abnormal diagnosis benchmark of the abnormal diagnosis based on the obtained characteristic estimation value and outputs it to the abnormal diagnosis unit.

7. The motor drive device according to claim 6, characterized in that: The characteristic estimation value is obtained by estimating at least any one of the following: Coulomb friction, viscous friction and moment of inertia of the motor; an amplitude of vibration at said location of said motor and a frequency of vibration at said location; a vibration amplitude of said speed and a vibration frequency of said speed of said motor; a vibration amplitude of the electric current of the electric motor and a vibration frequency of the electric current; a vibration amplitude of the torque of the motor and a vibration frequency of the torque; and Coulomb friction, viscous friction and moment of inertia of the drive mechanism.

8. The motor drive device according to claim 6, characterized in that: The driving instruction signal is the driving instruction signal in working operation.

9. The motor drive device according to claim 6, characterized in that: The operating condition includes at least any one of an operating mode, a type of workpiece, and an operation with interference.

10. A motor drive system, comprising: The motor drive device according to claim 1; and A host controller outputs the drive command signal and the characteristic estimation instruction signal to the motor drive device.

11. A motor drive system, comprising: The motor drive device according to claim 6; and A superior controller outputs the drive command signal and the abnormality diagnosis indication signal to the motor drive device.

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