JP5822794B2 - Motor control device - Google Patents

Description

  The present invention relates to a motor control device that drives an industrial machine such as a machine tool.

  As a device for controlling a motor that drives an industrial machine device, a rotational position (rotation angle) or speed of a motor is detected by a detector such as a rotary encoder connected to the motor, and a position detected with respect to a target value. There is a motor control device that controls the speed to follow.

  Further, the motor control device is generally provided with a protection function for detecting an abnormal state during driving. When an abnormal state is detected, warning information and alarm information are output depending on the type of abnormality.

  As an abnormal state detection means, for example, what determines that an abnormality occurs when a control signal inside the control device such as a position deviation or a current command value that is a deviation between the target value and the rotational position of the motor exceeds a predetermined threshold, Some signals are determined to be abnormal when a signal obtained from a connected detector or temperature sensor indicates a predetermined abnormal state.

  As described above, when an abnormal state is detected in the motor control device, it is desired to clarify the cause of the abnormal state. Therefore, a method has been proposed in which data at the time of occurrence of an abnormality is stored to facilitate analysis at the time of investigation.

  For example, the following techniques have been proposed as a method for storing data when an abnormality occurs. That is, there is disclosed a technique for storing position information, speed information, and temperature information as internal information of an encoder at a point in time before a predetermined time when data indicating abnormality is generated in a detector (see, for example, Patent Document 1). ).

Japanese Patent Laid-Open No. 2005-221258

  As described above, according to the conventional technology, it is possible to check the internal state at the time of occurrence of abnormality by storing various data at the time of occurrence of abnormality.

  However, since the data is only at the time of occurrence of an abnormality, for example, when an abnormality occurs depending on specific data, such as when a foreign object adheres to the inside of the detector and an abnormality occurs at a specific rotational position. In some cases, it took time to identify the factors.

  The present invention has been made in view of the above, and an object of the present invention is to provide a motor control device that can identify a factor when an abnormality occurs in a shorter time.

  In order to solve the above-described problems and achieve the object, the present invention includes a control unit that drives the motor based on a command signal that commands the operation of the motor and a detection signal that is a detection result of the operation of the motor. The abnormality of the motor is detected on the basis of the observation signal which is a detection signal, a driving position and a driving speed of a load machine driven by the motor, a signal generated inside the control means, or a sensor signal from the outside. An abnormality detection unit, an abnormality data storage unit that stores a plurality of times of anomaly occurrence of the observation signals for each abnormality occurrence, and a plurality of times of the observation signal stored in the abnormality data storage unit Dependency determining means for extracting the observation signal on which the occurrence of abnormality has a dependency based on a value at the time of occurrence of the abnormality.

  According to the present invention, the observation signal at the time of occurrence of an abnormality can be confirmed together with the signal at the time of occurrence of an abnormality in the past, and the dependency thereof can be determined, so that the identification of the factor at the time of occurrence of the abnormality can be realized in a shorter time. There is an effect that can be done.

FIG. 1 is a block diagram showing a motor control device according to an embodiment of the present invention. FIG. 2 is a table showing a storage example of the abnormal time data storage unit in the embodiment of the present invention. FIG. 3 is an example of display data output to the external display in the embodiment of the present invention. FIG. 4 is an example of display data output to the external display in the embodiment of the present invention, and represents the dependency of the position within one rotation of the motor in the detector. FIG. 5 is another example of the display data output to the external display in the embodiment of the present invention, and represents the dependency within the operating range of the machine.

  Embodiments of a motor control device according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment.
Hereinafter, a motor control device 100 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5. FIG. 1 is a block diagram showing a configuration of a motor control device 100 according to Embodiment 1 of the present invention.

  As shown in FIG. 1, a command signal for the operation of the motor 1 such as a position command and a speed command is input to the motor control device 100.

  The detector 2 is connected to the motor 1 and detects the rotational position (rotational angle) of the motor 1. Then, the detection result is output as a detection signal.

  The comparator 7 calculates and outputs a deviation between the command signal and the detection signal. The position controller 3 outputs a speed command signal based on the deviation between the command signal output from the comparator 7 and the detection signal.

  The comparator 8 calculates a deviation between the speed command signal output from the position control unit 3 and the speed detection signal output from the speed calculation unit 6. Here, the speed calculation unit 6 performs a process of converting to a speed based on the detection signal, and is configured by, for example, a differentiation process. That is, the speed detection signal corresponds to the motor rotation speed of the motor 1.

  The speed control unit 4 outputs a torque command signal based on the deviation between the speed command signal and the speed detection signal given from the comparator 8.

  The torque control unit 5 outputs a drive current for driving the motor 1 based on the input torque command signal.

  In addition, each control unit described above performs a calculation including a proportional calculation and an integral calculation, and a gain value necessary for the calculation is set.

  Thus, in the motor control device, the motor 1 is driven so as to follow the command signal.

  The abnormality detection means 9 is a detection signal output from the detector 2, a driving position and a driving speed of a load machine driven by the motor 1, a control signal generated inside the motor control device 100, and an output from a sensor 10 installed outside. Each signal is monitored and an abnormality is detected based on an observation signal such as a sensor signal. Here, as the control signal, for example, a positional deviation that is a deviation between the target value and the rotational position of the motor, a rotational speed of the motor, a current command value, or the like is used, and a sensor such as a temperature sensor in the motor 1 or the detector 2 is used. Used.

  The abnormal-time data storage unit 11 stores a plurality of observed signal values observed when an abnormality is detected by the abnormality detection unit 9 for a plurality of times each time an abnormality occurs.

  The dependence determination means 12 extracts an observation signal that is estimated to have a dependency on the occurrence of an abnormality based on the values of the plurality of observation signals stored in the abnormal data storage unit 11. Here, as a method for determining the dependency, for example, a standard deviation or a variance of values (observed values) stored for a plurality of times for each observation signal is obtained. When the standard deviation or variance, which is an evaluation value indicating the variation of these data, is equal to or less than a predetermined value, it is determined that the occurrence of abnormality has dependency on the observed signal.

  In addition, as another method for determining the dependency, the data range that the observation signal can take is divided by a predetermined number, and the corresponding number for each divided area (the number of times that the observation signal becomes the value of the area when an abnormality occurs) You may determine by calculating | requiring the ratio by digitizing. That is, when the frequency at which the observation signal becomes a value in the range of the specific area is equal to or higher than the predetermined frequency, the area is determined as an abnormality occurrence area.

  The data display means 13 is an external display device 14 connected to the motor control device 100 with a plurality of observation signals stored in the abnormal-time data storage section 11 or data having dependency relations extracted by the dependence determination means 12. Output for.

  Next, the format of the plurality of observation data that is observed, stored, and displayed as described above will be described in more detail with an example.

  FIG. 2 is a table showing a storage example of the abnormal data storage unit 11 in the embodiment of the present invention. As shown in FIG. 2, in the abnormality data storage unit 11, for the abnormalities occurring from the generation numbers 1 to N, the motor angle, motor speed, temperature obtained from the sensor, current, Remember the position. By referring to the data stored in this way, for example, in the storage example of FIG. 2, it is confirmed that an abnormal state has occurred at a position where the motor angle is near 0 [deg].

  FIG. 3 is an example of display data output to the external display 14 in the embodiment of the present invention. As shown in FIG. 2, each observation signal stored is normalized for each data range, and the horizontal axis indicates the generation number and is displayed in a graph. In the example of FIG. 3, the fluctuation rate of the observation signal indicated by data 1 is low, and it can be confirmed that the occurrence of abnormality has dependency on this observation signal (data 1).

  FIG. 4 is an example of display data output to the external display 14 in the embodiment of the present invention, and shows the dependency of the position of the motor 1 within one rotation in the detector 2. In FIG. 4, the location of the position within one rotation of the motor 1 at the time of occurrence of an abnormality is determined for each area divided by the division number N, and the abnormality occurrence area is color-coded by diagonal lines. Specifically, the number of times that a value is taken as the position within one rotation at the time of occurrence of an abnormality is totaled for each area, and an area having the number of times greater than or equal to a predetermined ratio is extracted as an abnormality occurrence area where the occurrence of abnormality is concentrated. . By displaying in this way, it becomes easy to visually determine an abnormality that occurs depending on a specific position within one rotation. On the contrary, when anomalies are scattered in a plurality of areas due to factors such as noise, a plurality of areas corresponding to the occurrence of anomalies occur, so that the factors can be separated.

  FIG. 5 is another example of display data output to the external display 14 in the embodiment of the present invention, and represents the dependence within the operating range of the load machine driven by the motor 1. In FIG. 5, the movable range in which the load machine connected to the motor 1 operates is determined for each region divided by the division number N, and the abnormality occurrence region is color-coded by hatching. Specifically, the number of times that a value is taken as a movable range when an abnormality occurs is totaled for each area, and an area that is a predetermined number of times or more is extracted as an abnormality occurrence area where the occurrence of an abnormality is concentrated. By displaying in this way, it is easy to visually determine the abnormality that occurs depending on the specific machine end position. For example, the abnormality that occurs at the specific machine end position due to bending of the cable is also specified. It becomes possible to do.

  As described above, in the motor control device 100 according to the embodiment of the present invention, the value of the observation signal at the time of occurrence of abnormality can be confirmed together with the value of the signal at the time of occurrence of abnormality in the past. At the same time, the dependency of the occurrence of an abnormality on the observed signal can be determined, so that it is possible to identify the factor when the abnormality occurs in a shorter time.

  Furthermore, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention in the implementation stage. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent requirements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the above embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and is described in the column of the effect of the invention. In the case where a certain effect can be obtained, a configuration from which this configuration requirement is deleted can be extracted as an invention. Furthermore, the constituent elements over different embodiments may be appropriately combined.

  As described above, the motor control device according to the present invention can realize the factor specification when an abnormality occurs in a shorter time, and is particularly suitable for a motor control device for a motor that drives an industrial machine.

DESCRIPTION OF SYMBOLS 1 Motor 2 Detector 3 Position control part 4 Speed control part 5 Torque control part 6 Speed calculation part 7, 8 Comparator 9 Abnormality detection means 10 Sensor 11 Abnormal data storage part 12 Dependency determination means 13 Data display means 14 External display 100 Motor control device

Claims (6)

Control means for driving the motor based on a command signal for instructing the operation of the motor and a detection signal which is a detection result of the operation of the motor;
An abnormality that detects an abnormality of the motor based on the observation signal that is the detection signal, the driving position of the load machine driven by the motor , the driving speed, a signal generated inside the control means, or a sensor signal from the outside. Detection means;
Abnormal data storage means for storing a plurality of values at the occurrence of abnormality of the plurality of observation signals for each occurrence of abnormality, and
Dependency determination means for extracting the observation signal having an abnormality occurrence based on the value at the time of abnormality occurrence of the observation signal for a plurality of times stored in the abnormality data storage means;
A motor control device comprising: The dependence determination means determines that the occurrence of abnormality has dependency on the observation signal when an evaluation value indicating a variation in value at the occurrence of abnormality of the observation signal for a plurality of times is equal to or less than a predetermined value. The motor control device according to claim 1. The motor control device according to claim 2, wherein the evaluation value indicating the variation is a standard deviation or a variance. The dependency determination unit, based on the value of the abnormality occurrence of the observed signal of the plurality of times stored in the abnormality data storage means, extract a range of values of the observation signal abnormality is concentrated The motor control device according to claim 1, wherein the motor control device is a motor control device. The dependence determination means divides the data range that the observation signal can take into a predetermined number of areas, and counts the number of times the observation signal takes a value when an abnormality occurs for each area, resulting in a number of times greater than a predetermined ratio. The motor control device according to claim 4, wherein a region is extracted as a range of values of the observation signal in which occurrence of abnormalities is concentrated. 6. The motor control device according to claim 4, further comprising an external display unit that displays a range of values of the observation signal in which occurrence of abnormality is concentrated together with a data range that the observation signal can take.

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