JP7776266B2 - Power transmission mechanism management device and program management system - Google Patents

Description

The present invention relates to a power transmission mechanism management device and a program management system. A non-limiting specific field of application is a management device that manages the operating status of a power transmission mechanism connected to an electric motor of industrial equipment (e.g., transport or machine tools) used in factories and businesses.

In general, various industrial equipment such as conveying equipment, injection molding machines, and presses are configured so that power is supplied from a power source (typically an electric motor that generates power using AC or DC current) to some kind of load device via a power transmission mechanism. The power transmission mechanisms for electric motors used in such industrial equipment can include various hardware components such as timing belts, ball screws, cams, and gears.

On the other hand, industrial equipment equipped with such power transmission mechanisms requires the use of various software programs and management data to monitor the status of the motors and power transmission mechanisms, and to manage the maintenance and durability of parts. For this reason, many industrial devices are equipped with functions to control the position, speed, and torque of the motors that drive the load-side devices, as well as functions to monitor the operating status of the motors, and a variety of other functions.

Furthermore, because once degradation begins in power transmission mechanisms such as belts, the degradation progresses rapidly, there is a demand for industrial equipment systems equipped with the ability to detect abnormalities in such power transmission mechanisms. For example, Patent Document 1 describes an abnormality diagnosis device and method equipped with the ability to detect abnormalities in power transmission mechanisms (belts, etc.). The technology described in Patent Document 1 focuses on the fact that when a belt or other device driven by an electric motor deteriorates, the frequency with which the signal strength of the current flowing through the motor increases (the frequency with which spectral peaks occur) increases, and describes how abnormalities in the power transmission mechanism are detected by, for example, performing an FFT analysis of the current.

International Publication No. 2018/109993

However, when attempting to implement an anomaly detection function such as that described in Patent Document 1 using a software program, if the power transmission mechanism connected to the electric motor is changed, it may become necessary to change the algorithm used.

For example, if the power transmission mechanism is changed from a timing belt to a ball screw, the driving mode of the electric motor itself will change, making it necessary to change the algorithm used and ultimately the entire software program that performs the anomaly detection function.

In contrast, conventional industrial equipment has limitations such as the resources of its built-in computing devices and storage devices, and is therefore limited to a limited number of implemented functions, making it impossible to execute functions other than those already implemented. As a result, when additional functions are required or when users wish to use upgraded or newly developed functions (such as an anomaly detection algorithm), it is necessary to introduce (purchase, lease, etc.) new industrial equipment with the added functions. Against this backdrop, there is a growing need or desire in the industrial equipment field for the ability to add new functions or change existing functions without having to replace equipment.

The object of the present invention is to provide a powertrain mechanism management device and software management system that makes it easy to add or change software functions that manage powertrain mechanisms and data related to those functions.

A brief summary of the representative inventions disclosed in this application is as follows:

A power transmission mechanism management device according to a representative embodiment of the present invention comprises an operation control unit that controls the electric motor to cause the power transmission mechanism to perform a predetermined operation; a state management unit that executes a first management program and manages the state of the power transmission mechanism based on input information input from the electric motor; an external communication unit that communicates with an external device to obtain a second management program corresponding to the type of power transmission mechanism; an update unit that replaces the second management program with the first management program and updates it so that it can be executed by the state management unit; and a library memory that stores multiple second management programs, wherein the first management program or the second management program is an abnormality detection program that causes the state management unit to determine whether or not there is an abnormality in the power transmission mechanism, the update unit selectively reads out the second management program from the library memory and replaces the read second management program with the first management program stored in the execution memory , and the external communication unit, when communicating with the external device, outputs to the external device one of the second management programs stored in the library memory that has become less frequently used.

The effects achieved by representative inventions disclosed in this application can be briefly explained as follows:

In other words, in a powertrain mechanism management device according to a representative embodiment of the present invention, the existing first management program is replaced with a second management program tailored to the type of powertrain device, and the second management program is updated so that it can be executed by the status management unit. This makes it easy to add or change software functions that manage the powertrain mechanism and data related to those functions.

Furthermore, even if it is necessary to add a function that has not yet been implemented in the management device, or if it is necessary to add a newly developed function (such as an anomaly detection algorithm), the function can be used by obtaining and updating the second management program via the external communications unit, eliminating the need to introduce new industrial equipment and reducing costs.

1 is a block diagram for explaining the configuration of a power transmission mechanism management device (motor control device) and an industrial equipment system (program management system) according to a first embodiment. 10 is a flowchart showing an example of processing of an abnormality detection program for diagnosing deterioration of a power transmission mechanism. 3 is a graph showing the state of an abnormality detection operation when the abnormality detection program shown in FIG. 2 is executed, together with the waveforms of motor operation information (p(t), v(t), iq(t)). 10 is a flowchart illustrating another example of the processing of an abnormality detection program for diagnosing deterioration of a power transmission mechanism, showing an algorithm to which an abnormality detection teacher data switching function has been added. FIG. 10 is a block diagram illustrating the configuration of another embodiment of the motor control device, which is an example in which the contents (algorithm) of the motor control program to be executed can be updated. FIG. 6 is a diagram illustrating a hardware configuration (inverter circuit) that is equivalent to or similar to the program configuration illustrated in FIG. 5 . FIG. 10 is a flowchart showing an outline of a process for acquiring and updating a new function program.

Each embodiment of the present invention will be described below. Each embodiment described below is an example for realizing the present invention and does not limit the technical scope of the present invention. In the examples, components having the same function will be assigned the same reference numerals, and repeated explanations will be omitted unless particularly necessary.

<Overview>
First, an outline of an embodiment to which the present invention is applied will be described. The following embodiment is realized as a power transmission mechanism management device (hereinafter simply referred to as a "management device") that manages a power transmission mechanism that transmits power from an electric motor used in an industrial equipment system to a load-side device in an industrial equipment system in which multiple industrial equipment operate in cooperation with each other.

The management device includes an operation control unit that operates the power transmission mechanism by performing feedback control on the electric motor so that the operation of the power transmission mechanism corresponds to the operation of a linked device that is linked to the power transmission mechanism;
a state management unit that manages the state of the power transmission mechanism through signals by using input information data (hereinafter sometimes referred to as "related data") input (feedback) from the electric motor to the operation control unit by expanding and executing a management program (first management program) in a working memory;
an external communication unit (which may also be referred to as a "management program acquisition unit") that communicates with an external device to acquire a management program (second management program) corresponding to the type of power transmission mechanism;
and an update unit that replaces the acquired management program (second management program) with the management program (first management program) in the working memory, thereby updating the status management unit so that it can be executed.

By providing the above configuration, it becomes possible to easily add or change software functions implemented in the management device and related data derived from or associated with those software functions.

An embodiment that embodies the above configuration will be described in detail below with reference to the drawings. Note that in the following example, the functions of the operation control unit, status management unit, management program acquisition unit, and update unit are executed by the same (single) hardware processor; however, in other examples, these functions may be executed by multiple hardware processors.

(Embodiment 1)
1 is a block diagram for explaining the configuration of a power transmission mechanism management device (motor control device) and an industrial equipment system (program management system) according to embodiment 1. Hereinafter, the industrial equipment system 1 shown in FIG. 1 will be abbreviated as "this system" where appropriate.

This system is constructed so that multiple pieces of industrial equipment operate in coordination, and Figure 1 shows only some of the main pieces of equipment. Specifically, the equipment that makes up this system includes a controller 2, a motor control device 3, an electric motor 4, a power transmission mechanism (a ball screw 5 is shown as an example in Figure 1), an operation terminal 6, a server 10, an upstream device 60 located upstream of the ball screw 5 in the conveying direction, and a downstream device 70 located downstream of the ball screw 5 as a load device.

Of the above devices (industrial equipment) that make up this system, the primary role of the motor control device 3 is to control the operation of the electric motor 4 and the power transmission mechanism connected to the electric motor 4. In addition, the motor control device 3 in this embodiment can also be equipped with a function to diagnose the state of the power transmission mechanism (presence or absence of abnormalities).

Of the above, the power transmission mechanism and the load-side device are the same in that they both transmit and utilize the power of the electric motor 4. However, in terms of the magnitude of the load, the load on the power transmission mechanism is usually smaller. However, depending on the gear ratio set in the power transmission mechanism and the mass of the moving parts within the power transmission mechanism, the load on the power transmission mechanism may be greater than that on the load-side device. For the sake of convenience, the following explanation will assume that the load on the power transmission mechanism is smaller than that on the load-side device. The function of diagnosing the presence or absence of an abnormality in the power transmission mechanism in the electric motor control device 3 will be described in detail later.

As a specific example, this system is assumed to be a system consisting of multiple pieces of industrial equipment installed in an assembly plant for electrical appliances manufactured by assembling multiple parts. However, in this embodiment, the locations where individual pieces of industrial equipment are installed (placed) are not particularly limited, and they can also be placed in various other locations, such as within any facility or at a construction site.

In addition, in this system, to coordinate operations between devices (industrial equipment), particularly between the controller 2, motor control device 3, operation terminal 6, and server 10, they are connected so that data can be sent and received between them via existing communication networks (in this example, the wide area communication network 100, which is a public communication network, and the communication network 102, which is an industrial communication network). Of these, the server 10, operation terminal 6, etc. can be located in a location remote from the other industrial equipment that makes up this system.

<server>
The server 10 is a server (e.g., an FTP server) that provides software function programs and corresponds to an "external device." The server 10 includes a processor such as a CPU, a communication unit such as a modem, a data storage unit such as a HDD, a display unit such as an LCD, and an operation input unit such as a keyboard or a mouse. These components are well known, so illustrations and detailed descriptions are omitted.

In the example shown in Figure 1, the server 10 stores anomaly detection program library group 11 and anomaly detection data library group 12 in the data storage unit. Of these, the anomaly detection program library group 11 is a collection of multiple (N types) anomaly detection programs (see Figure 1 as appropriate) that are acquired and executed by the motor control device 3.

Here, "multiple (N types)" is not particularly limited and can be any number. For example, there could be N types of abnormality detection programs depending on the type of power transmission mechanism that may be used in this system. Alternatively, even if the type of power transmission mechanism used is the same, different types of abnormality detection programs could be used depending on the type (model number, etc.) of the electric motor 4 controlled by the electric motor control device 3. Furthermore, even if the type of power transmission mechanism and the type (model number, etc.) of the electric motor 4 are the same, the abnormality detection program after a so-called upgrade can be treated as a different type from the abnormality detection program before the upgrade.

On the other hand, the anomaly detection data library group 12 in the server 10 is data (associated data) used by each of the multiple (N types) anomaly detection programs mentioned above. This associated data includes, for example, various information used by the anomaly detection program to determine whether or not a specific type of power transmission mechanism has an abnormality, such as input information (waveform data, etc.) for the electric motor 4, functions used, and thresholds for determining whether or not an abnormality exists.

In the following explanation, it is assumed that the above-mentioned associated data or part of the associated data is data that can be acquired by the motor control device 3 when the corresponding anomaly detection program is executed. For this reason, in this system, it is not necessary to prepare all of the associated data for multiple (N types) anomaly detection programs on the server 10 as the anomaly detection data library group 12. However, when an anomaly detection program supplied from the server 10 is used (executed) for the first time on the motor control device 3, it may be necessary to set some reference value or initial value. For this reason, it is desirable for the anomaly detection data library group 12 to include the minimum necessary data (reference values, initial values, etc.) from the data (associated data) used by each of the above-mentioned multiple (N types) anomaly detection programs.

Furthermore, when software developers upgrade existing anomaly detection programs and add them to the anomaly detection program library group 11, or when developing an anomaly detection program with new functions or control methods, the related data (so-called measured data) acquired by the motor control device 3 is likely to be useful. For this reason, in this system, it is preferable to enable the related data acquired by the motor control device 3 to be transmitted (provided) to the server 10 directly or via the controller 2 via the above-mentioned communication network (100, 102). By providing data in this manner, it is expected that the anomaly detection program library group 11 in the server 10 will be enriched.

<controller>
In this system, the primary role of the controller 2 is to output control signals (commands to start or stop the operation of the motor 4, setting signals related to basic operations of the motor 4 that are set in advance (reserved), etc.) to the motor control device 3. Examples of the controller 2 include a PLC (Programmable Logic Controller) and a motion controller.

In addition, in this embodiment, the controller 2 has the function of saving and managing the software function programs used by the motor control device 3, as well as the function of saving and managing the above-mentioned related data generated by the execution of these software function programs. Therefore, the controller 2 also corresponds to an "external device."

Such a controller 2 includes a CPU 20 that controls the entire controller 2, a communications unit such as a communications card for wired or wireless communications, a data storage unit such as a HDD, a display unit such as an LCD, and an operation input unit such as key switches. Note that the above-mentioned hardware configuration itself is well known, so detailed description thereof will be omitted where appropriate.

In Figure 1, an example is shown in which three types of anomaly detection programs (A) 211, (B) 212, and (C) 213 are stored as program library 21 in the data storage section of controller 2, and data (221-223) used by these anomaly detection programs is stored as data library 22. That is, anomaly detection data (A) 221 in data library 22 is data used for anomaly detection program (A) 211, anomaly detection data (B) 222 is data used for anomaly detection program (B) 212, and anomaly detection data (C) 223 is data used for anomaly detection program (C) 213.

The CPU 20 of the controller 2 also functions as an output control unit that outputs any one of the abnormality detection programs (A) 211, (B) 212, and (C) 213 (second management program) stored in the data storage unit to the motor control device 3 via the communication unit.

In addition, the CPU 20 of the controller 2 has the function of managing the abnormality detection program, etc. used by the motor control device 3, for example by checking the identity of the abnormality detection program stored in the data storage unit with the abnormality detection program and abnormality detection data (hereinafter referred to as the abnormality detection program, etc.) stored in the library memory 32 of the motor control device 3.

In one specific example, the data storage unit of the controller 2 has a capacity large enough to store more data (anomaly detection programs and anomaly detection data) than the library memory 32 of the motor control device 3. This configuration makes it easier to manage data, for example, by storing anomaly detection programs and the like in the motor control device 3 that are no longer used frequently in the data storage unit of the controller 2, and instead moving anomaly detection programs and the like that will be used in the near future from the controller 2 to the motor control device 3 (memory 32).

<Operation terminal>
The operation terminal 6 has the function of outputting various commands to any of the devices constituting the system, such as the server 10, the controller 2, and the motor control device 3. In the example shown in FIG. 1 , the operation terminal 6 is a laptop PC, and compared to the controller 2 described above, it has a larger display area, more key switches, and a larger data storage capacity. For this reason, the operation terminal 6 may function as an "external device" similar to the controller 2. However, to avoid complicating the explanation, only functions unique to the operation terminal 6 will be mentioned below. Furthermore, the hardware configuration of the operation terminal 6 is the same as that of the server 10 described above and is publicly known, so illustrations and detailed description thereof will be omitted.

<Communication Network>
In this system, the controller 2, motor control device 3, operation terminal 6, and server 10 are capable of exchanging data with each other via a wide area communication network 100 (public communication network). For example, by operating the operation terminal 6, a user can operate and monitor the server 10 and controller 2, and send the operating status of the motor control device 3 from the controller 2 to the server 10 and operation terminal 6.

The wide area communication network 100 may be implemented wirelessly as well as wired. For example, when communicating wirelessly between devices, an access point 101 conforming to a communication protocol such as Wi-Fi (registered trademark) or Bluetooth (registered trademark) may be provided within the wide area communication network 100, and the controller 2 and operation terminal 6 may be equipped with a compatible antenna circuit and driver (see Figure 1 as appropriate).

In this system, the controller 2 and the motor control device 3 are able to exchange data with each other via the communication network 102. In one specific example, the controller 2 can transmit operation commands generated by the controller 2 to the motor control device 3, and conversely, the controller 2 can receive the operating status of the motor control device 3.

The communication network 102, which serves as an industrial communication network, communicates using a so-called industrial communication protocol (such as EtherCAT (registered trademark)), but may also be an input/output interface for analog signals.

In another system configuration example, the motor control device 3 may be directly connected to the wide area communication network 100, in which case the controller 2 may be omitted.

<Electric motor>
The electric motor 4 is an electric motor that rotates an internal rotor (not shown) and a rotating shaft 41 integral with the rotor when supplied with electric power. In one specific example, the electric motor 4 is a servomotor operated by three-phase alternating current (AC). This servomotor rotates the rotor around the rotating shaft 41 using AC voltage and control signals input from the motor control device 3, and sends a feedback signal as motor operation information during the rotation. The motor control device 3 then inputs the feedback signal to perform feedback control of the operation of the electric motor 4 (e.g., rotation direction, speed, time, stop position and timing). Regarding the feedback signal, for example, as shown in FIG. 6 , a position detector 7 such as a rotary encoder can be attached to the rotating shaft 41, and the detected value of the position detector 7 can be input to the motor control device 3 to obtain the rotor position (rotational position information) of the electric motor 4. Note that the type of the electric motor 4 (e.g., DC/AC power supply system, rotary or linear power generation system, etc.) is not particularly limited in the present invention.

<Power transmission mechanism>
1 illustrates an example in which a ball screw 5 is used as a power transmission mechanism for transmitting the power of the electric motor 4. The ball screw 5 is a device that converts the power generated by the rotational motion of the electric motor 4 into linear motion and transports a placed part or the like (workpiece W).

In one specific example, the ball screw 5 includes a screw shaft 51 connected (coupled) to the rotating shaft 41 of the electric motor 4, a housing (not shown) that rotatably holds the screw shaft 51, a nut attached to the screw shaft 51, and a workpiece mounting portion 52 that is integral with the nut.

When the screw shaft 51, which rotates integrally with the rotor of the electric motor 4, rotates in the direction of arrow 41a in Figure 1 (e.g., clockwise), the workpiece placement section 52 moves in one direction (e.g., to the left in Figure 1) in accordance with the rotational direction of the screw shaft and the shape of the spiral groove, thereby transporting the workpiece W mounted on its upper surface in the same direction. The transported workpiece W is then handed over to a linked device (downstream device 70) located downstream of the transport path.

After this, when the screw shaft 51 rotates counterclockwise (in the direction of arrow 41b) based on the control of the electric motor 4 by the electric motor control device 3, the workpiece placement unit 52 moves in the opposite direction to the above, in this example, to the right in Figure 1. In other words, the workpiece placement unit 52 moves to its initial position or a predetermined standby position to load the next workpiece supplied from the upstream device 60 (for example, a robot that picks up parts) and transport it to the downstream device 70.

Here, the downstream device 70 is a load-side device (industrial equipment) that utilizes the power of the electric motor 4, and is, for example, a belt conveyor (not shown). Generally, a belt conveyor comprises a pair of rollers, a belt stretched over the two rollers, and a support (frame) that rotatably holds the rollers and supports the belt in a position where it does not contact the ground. The roller shaft of one of the rollers in the belt conveyor is connected to the screw shaft 51 (rotating shaft) of the ball screw 5 via a one-way clutch, so that the workpiece W transferred onto the belt from the ball screw 5 is transported in only one direction (perpendicular to the plane of the paper in Figure 1).

In other words, when the screw shaft 51 of the ball screw 5 rotates in a direction opposite to the work transport direction (returning direction, i.e., to the right in Figure 1), the rollers and belt of the belt conveyor rotate in a direction that transports the work on the belt surface, transporting the work W on the belt. Conversely, when the screw shaft 51 of the ball screw 5 rotates in a direction that corresponds to the work transport direction (to the left in Figure 1), the rollers and belt of the belt conveyor come to a standstill or stop due to the action of the one-way clutch.

By repeating this operation, the belt conveyor stops until the workpiece W is transferred from the ball screw 5 to the belt conveyor, and the belt conveyor can transport the workpiece W on the belt while the ball screw 5 rotates in the return direction to load a new workpiece. This configuration allows for efficient use of the power of the electric motor 4.

Note that the above-described linked operation and form of utilization of the power of the electric motor 4 are just examples, and the power of the electric motor 4 can be utilized by combining various other types of power transmission mechanisms and linked devices (load-side devices).

<Motor control device>
In this system, the motor control device 3 has the function of controlling the operation of the motor 4 and the ball screw 5 in order to smoothly perform the linked operation between the devices (industrial equipment) described above.

As shown in FIG. 1, the motor control device 3 includes a control unit 30 that handles overall control of the motor control device 3, an external communication unit 31 for communicating with external devices via the above-mentioned communication networks (100, 102), a library memory 32 for storing programs and data, and an execution memory 33 for executing various programs. The motor control device 3 also includes an operation display unit 36, such as a touch-panel LCD display. The operation display unit 36 displays the status of each part of the motor control device 3 under display control by the control unit 30. The operation display unit 36 also inputs operation signals to the control unit 30 in accordance with touch operations by the user.

Of the above, the execution memory 33 is a volatile memory such as random access memory (RAM), and functions as a working area for expanding or temporarily storing various programs and data used by the control unit 30.

On the other hand, in one example, the library memory 32 is a non-volatile memory separate from the above-mentioned memory 33, and various storage devices for data storage, such as HDD, EEPROM, and flash memory, can be used. Compared to the execution memory 33, the library memory 32 does not require high-speed read/write, but it has a larger data storage capacity than the execution memory 33 so that it can store multiple programs and the data obtained by executing those programs.

In this embodiment, memory 32 and memory 33 are connected via switches 34 and 35. Of these, switch 34 functions as a switching unit for selectively reading multiple anomaly detection programs stored in library memory 32 into execution memory 33. On the other hand, switch 35 functions as a switching unit for selectively reading or saving anomaly detection data between memory 32 and memory 33. These switches 34 and 35 are so-called logical switches that are switched under the control of control unit 30. As another example, memory 32 and memory 33 may be the same storage medium (e.g., large-capacity RAM), in which case switches 34 and 35 are not necessary.

The control unit 30 is configured with a microcomputer for embedded devices, including a processor such as a CPU or MPU, a ROM storing basic programs, and various I/O interfaces, and is designed to perform various functions in cooperation with the programs.

In the example shown in Figure 1, the library memory 32 stores an abnormality detection program (A) for diagnosing deterioration of the ball screw 5 described above (hereinafter, sometimes referred to as ball screw deterioration diagnosis program 321A), and an abnormality detection program (B) for diagnosing deterioration of the bearing that rotatably supports the rotating shaft 41 of the electric motor 4 (hereinafter, sometimes referred to as bearing deterioration diagnosis program 321B).

In this embodiment, bearing deterioration diagnosis program 321B corresponds to the "first management program," and ball screw deterioration diagnosis program 321A corresponds to the "second management program." In other words, in this system, when the electric motor 4 is replaced, the electric motor control device 3 is also replaced, so bearing deterioration diagnosis program 321B is implemented as the default software function program (first management program). On the other hand, since it is assumed that the power transmission mechanism connected to the electric motor 4 will be replaced, Figure 1 shows the state after ball screw deterioration diagnosis program 321A (second management program) has been acquired from an external device (server 10 or controller 2).

Also, the library memory 32 stores, as associated data, abnormality detection data (A) 322A used in the above-mentioned ball screw deterioration diagnosis program 321A, and abnormality detection data (B) 322B used in the above-mentioned bearing deterioration diagnosis program 321B. The abnormality detection data (A) 322A and the abnormality detection data (B) 322B are each data generated based on input information input from the electric motor 4. The contents of these programs and data will be described in detail below.

Meanwhile, the execution memory 33 stores an electric motor control program 331 for controlling the operation of the electric motor 4, an abnormality detection program 332, and abnormality detection data 333 used by the abnormality detection program 332. Here, the abnormality detection program 332 is either the ball screw deterioration diagnosis program 321A or the bearing deterioration diagnosis program 321B stored in the library memory 32. Similarly, the abnormality detection data 333 is either the abnormality detection data (A) 322A or the abnormality detection data (B) 322B (data corresponding to the abnormality detection program 332) stored in the library memory 32.

In other words, the control unit 30 of the motor control device 3 performs the following functions as an "update unit." That is, the control unit 30 selectively reads the abnormality detection program 332 in the execution memory 33 from multiple (two in this example) abnormality detection programs 321A, 321B stored in the library memory 32, and outputs the read abnormality detection program (321A or 321B) to the execution memory 33, thereby setting or updating (replacing) the abnormality detection program 332.

The above operation allows a deterioration diagnosis program appropriate for the type of power transmission mechanism to be executed, allowing the presence or absence of an abnormality in the power transmission mechanism to be determined. The method for this determination will be described later.

<Motor control device operation>
Next, an overview of the operation of the motor control device 3 will be given. The control unit 30 of the motor control device 3 starts the motor control program 331 in the execution memory 33 and waits in an executable state for drive control of the motor 4. The control unit 30 also starts the abnormality detection program 332 in the execution memory 33. The control unit 30 then reads the corresponding abnormality detection data 333 and waits in an executable state for the processing (algorithm) described in the abnormality detection program 332.

After this, when the control unit 30 receives an operation command as a control signal from the controller 2, operation terminal 6, or operation display unit 36 (hereinafter referred to as controller 2, etc.), it starts driving the electric motor 4 in accordance with the electric motor control program 331 and controls its operation. In detail, the operation of the electric motor 4 is preset in the electric motor control program 331 so that it operates (drives) in a manner that corresponds to the operation of the power transmission mechanism and linked devices (upstream device 60 and downstream device 70 shown in Figure 1) used in this system. Such operation settings can be made through a setting screen (not shown) and operational input from the controller 2, etc.

The control unit 30 of the motor control device 3 controls the operation of the motor 4 (adjusting the rotor's rotation direction, rotation speed, stop timing, etc.) according to the settings in the motor control program 331, thereby controlling (adjusting) the operation of the power transmission mechanism (ball screw 5 in the example of Figure 1) and achieving coordinated operation with the linking device (such as transporting the workpiece W). At this time, the control unit 30 of the motor control device 3 acquires motor operation information (input information) indicating the operating state of the motor 4, such as the rotor position, rotation speed, and input current of the motor 4, as feedback signals via the position detector 7, current detector 125 (see Figure 6), etc., and performs feedback control using this input information. The acquired input information (such as the waveform signal described later in Figure 3) can be displayed on any display unit (e.g., the operation display unit 36 or the display unit of the controller 2 or operation terminal 6) for user monitoring.

In this embodiment, the control unit 30 of the motor control device 3 executes the abnormality detection program 332 stored in the execution memory 33 while executing the motor control program 331. In other words, the control unit 30 executes the algorithms described in the motor control program 331 and the abnormality detection program 332 in parallel or simultaneously.

In this example, an abnormality detection algorithm that detects an abnormal state (presence or absence of an abnormality) of the ball screw 5 is stored in the abnormality detection program (A) 321A. Therefore, the control unit 30 deploys the abnormality detection program (A) 321A in the memory 33 and executes it as the abnormality detection program 332, making it possible to detect the presence or absence of an abnormality in the ball screw 5, which is the power transmission mechanism. The control unit 30 of the electric motor control device 3 performs the following functions as a "status management unit" based on the abnormality detection algorithm of the abnormality detection program (A) 321A.

That is, the control unit 30 analyzes the operating conditions (input information) such as the rotor position and rotational speed of the electric motor 4 described above through the abnormality detection program 332 (in this example, abnormality detection program (A) 321A), and stores the analysis results in the execution memory 33 as actual measurement data or training data (see abnormality detection data 333). The control unit 30 also compares the abnormality detection data 333, which has been measured in advance and stored in the memory 33, with the current analysis results obtained by the abnormality detection program 332, and if there is a large discrepancy between the values, determines that there is an abnormality in the ball screw 5 (power transmission mechanism) and outputs an abnormality signal.

In detail, the control unit 30 determines whether or not there is an abnormality in the ball screw 5 (power transmission mechanism) based on the criterion of whether the value indicated by the input wave in the motor operation information deviates from the threshold value set in the training data.

More specifically, if the distortion of the waveform (wave shape) in the motor operation information exceeds a threshold value set in the training data, the control unit 30 determines that there is an abnormality in the power transmission mechanism (ball screw 5) and outputs an abnormality signal to that effect.

The output abnormal signal can be displayed (output) on the display unit showing motor operation information (waveforms, etc.) as a message notifying the user of the abnormality, or as an image such as a warning sound or icon, thereby notifying or warning the user of the industrial equipment. Therefore, by monitoring the content of the display unit (such as whether or not an abnormal signal is being output), users of this system (administrators, etc.) can monitor or predict abnormal conditions in the power transmission mechanism (ball screw 5).

The above example assumes that the power transmission mechanism connected to the electric motor 4 is a ball screw 5, and the presence or absence of an abnormality in the ball screw 5 is determined through the execution of the abnormality detection program (A) 321A. As another example, if the power transmission mechanism connected to the electric motor 4 is a mechanism other than a ball screw 5 (e.g., a gearbox), the control unit 30 executes a software function program having a different abnormality detection algorithm (e.g., the abnormality detection program (C) 213 shown in FIG. 1, or a corresponding abnormality detection program in the abnormality detection program library group 11 of the server 10).

In other words, the control unit 30 acquires software function programs corresponding to the type of power transmission mechanism for which abnormality detection is to be determined from an external device as appropriate, stores them in the library memory 32 and eventually the execution memory 33, and executes them. By operating in this manner, in other words, by updating (replacing) the software function programs stored and executed in the execution memory 33 according to the power transmission mechanism being used, it becomes possible to determine (diagnose) the presence or absence of abnormalities in various types of power transmission mechanisms connected to the electric motor 4.

Furthermore, the control unit 30 can obtain the relevant abnormality detection program from the abnormality detection program library group 11 of the server 10, store (and update as appropriate) it in the library memory 32 and eventually in the execution memory 33, and execute it to determine (diagnose) whether or not there is an abnormality in the load-side device (downstream device 70).

<Example of anomaly detection program operation>
Next, an example of the operation of the abnormality detection program will be described in more detail with reference to Figures 2 and 3. Figure 2 is a flowchart showing an example of the processing of an abnormality detection program for diagnosing deterioration of a power transmission mechanism. Figure 2 is a processing flow showing a part of the algorithm described in the above-mentioned ball screw deterioration diagnosis program 321A (the abnormality detection program (A) shown in Figure 1).

The ball screw deterioration diagnosis program 321A is configured to selectively execute two operating modes (algorithms): an abnormality detection training data acquisition mode and an abnormality detection operating mode. The user can specify or change the setting of which operating mode to execute by operating the controller 2, etc.

In step S1 after launching the ball screw deterioration diagnosis program 321A, the control unit 30 of the motor control device 3 determines whether the operating mode of the motor control device 3 is the teacher data acquisition mode.

Here, if the control unit 30 determines that the operating mode is teacher data acquisition mode (step S1, YES), it proceeds to step S2, acquires teacher data through the processing of steps S2 to S4 described below, and then returns to the determination processing of step S1 described above.

On the other hand, if the control unit 30 determines that the operating mode is not the teacher data acquisition mode (step S1, NO), it determines that the operating mode is the abnormality detection mode and proceeds to step S5. After diagnosing the presence or absence of an abnormality in the ball screw 5 through the processing of steps S5 to S10 described below, it returns to the judgment processing of step S1 described above.

First, we will explain the operation in the abnormality detection teacher data acquisition mode (hereinafter simply referred to as "teacher data acquisition mode"). In step S2, the control unit 30 waits until it receives a command (teacher data acquisition operation start command) from the controller 2 or the like (i.e., a user input operation) to start acquiring teacher data that will serve as the criteria for detecting an abnormality in the ball screw 5, and proceeds to step S3 when this command is received.

The waiting period in step S2 takes into account the fact that it may take some time for the rotational state of the electric motor 4 to stabilize, for example, when the ball screw deterioration diagnosis 321A is started simultaneously with normal operation. In other words, by suspending acquisition of training data until the rotational state of the electric motor 4 stabilizes, the control unit 30 can acquire more accurate training data in the processing of steps S3 and S4 below.

In step S3, the control unit 30 acquires various pieces of operating information (in this example, p(t), v(t), and iq(t)) based on input signals (feedback information) detected from the electric motor 4. Of these, p(t) is rotational position information of the electric motor 4 at time t. Furthermore, v(t) is rotational speed information of the electric motor 4 at time t. These p(t) and v(t) can be acquired from the detection signal of the position detector 7 described above. Furthermore, iq(t) is torque current information of the electric motor 4 at time t, and is acquired or calculated from the current (AC in this example) input (feedback) from the electric motor 4 to the control unit 30.

In the following step S4, the control unit 30 derives anomaly detection training data by substituting the motor operation information (p(t), v(t), iq(t)) into the formula predefined in parentheses () in accordance with the first anomaly detection algorithm (= fan1 (formula)).

The control unit 30 then returns to step S1, and while it determines that the operating mode is the teacher data acquisition mode (step S1, YES), it continues to derive anomaly detection teacher data by repeatedly executing the processes of steps S3 and S4 described above. Note that with respect to step S2, the control unit 30 skips the standby process described above from the second time onwards.

Figure 3 is a graph showing the anomaly detection operation during execution of the anomaly detection program shown in Figure 2, along with the waveforms of the motor operation information (p(t), v(t), iq(t)).

In Figure 3, the first, second, and third graphs from the top are waveform diagrams of the motor operation information input to the control unit 30. That is, the first graph from the top is a waveform diagram showing the rotational position p(t) of the motor 4, the second graph is a waveform diagram showing the rotational speed v(t), and the third graph is a waveform diagram showing the torque current iq(t), and each diagram schematically shows how the waveform deteriorates over time. Looking at these three graphs, it can be seen that distortion occurs in each waveform and that this distortion becomes larger over time.

Normally, when an abnormality occurs in the electric motor 4 or the load-side device (downstream device 70 in Figure 1), it often manifests as an abnormality in the waveform period or amplitude (for example, a change in period due to an abnormality in the rotational speed, or a change in amplitude due to an abnormality in the torque current).

In contrast, if an abnormality occurs in the power transmission mechanism (such as the screw shaft 51 of the ball screw 5 in this example), which has a significantly smaller load than the downstream device, the waveform will be distorted as shown on the right side of Figure 3. In other words, when an abnormality occurs in the power transmission mechanism, minute vibration waves (hereinafter referred to as micro-vibration waves) are generated in the waveforms of the rotational position p(t), rotational speed v(t), and torque current iq(t) in the motor operation information. The greater the degree of abnormality in the ball screw 5 (e.g., the degree of wear or distortion of the screw shaft 51), the more pronounced the micro-vibration waves become in their amplitude components. Furthermore, because micro-vibration waves such as those shown in Figure 3 can be detected as a change in amplitude or wave gradient over a small time period t, it can be determined or inferred that there is an abnormality in the condition of the ball screw 5, rather than an abnormality in the electric motor 4 or the downstream device 70 (load side device).

In light of the above-described circumstances, in this embodiment, it is desirable that the operation of the anomaly detection teacher data acquisition mode described above in FIG. 2 be executed (implemented) primarily in a normal state where no degradation of the ball screw 5 has occurred (e.g., during the initial operation of the system). By executing the operation of the anomaly detection teacher data acquisition mode (steps S3, S4, etc. in FIG. 2) in such a normal state, anomaly detection teacher data based on a normal, distortion-free waveform can be generated, as shown on the left side of FIG. 3. This anomaly detection teacher data serves as reference information (teacher data in supervised machine learning) for determining anomalies in the anomaly detection mode described below.

Here, the fourth graph from the top in Figure 3 shows an example in which the magnitude of distortion (change in amplitude or change in wave gradient over a short time t) of one of the above waveforms (e.g., torque current iq(t)) exceeds a threshold, causing the signal representing a normal state (e.g., "0" in the binary value (0/1)) to switch to a signal representing an abnormal state (e.g., "1").

Furthermore, the fifth graph from the top in Figure 3 shows an example of switching from operation in the anomaly detection operation mode described above to operation in the anomaly detection mode. In one specific example, the timer function of the motor control device 3 can be used to operate the system in the anomaly detection teacher data acquisition mode only on the initial operating day of the system, and then in the anomaly detection mode from the following day.

Next, referring again to Figure 2, we will explain the operation of the abnormality detection mode during execution of the ball screw deterioration diagnosis program 321A.

In step S5, the control unit 30 of the electric motor control device 3 waits until it receives a command (anomaly detection operation start command) from the controller 2 or the like (i.e., a user input operation) to start operation to detect abnormalities in the ball screw 5, and proceeds to step S6 when this command is received. Note that the significance of waiting in step S6 is the same as in step S2 described above. In other words, by suspending the abnormality detection operation until the rotational state of the electric motor 4 stabilizes, unnecessary erroneous detections are prevented in the processing of the following steps S6 to S10, and more accurate condition detection can be achieved.

In step S6, the control unit 30 acquires various motor operation information (in this example, p(t), v(t), and iq(t)) based on the input signals (actually measured detection signals or feedback signals). The processing in step S6 is similar to that in step S3 described above, so a detailed description will be omitted.

In the following step S7, the control unit 30 derives the anomaly detection measurement data by substituting the motor operation information (p(t), v(t), iq(t)) into the formula in parentheses according to the first anomaly detection algorithm (=fan1(formula)). Note that the method for deriving the data in step S7 is the same as the method for deriving the anomaly detection training data in step S4 described above.

In the next step S8, the control unit 30 compares the derived anomaly detection actual measurement data with the anomaly detection teacher data described above, calculates the difference between the two, and then proceeds to step S9. In step S9, the control unit 30 determines whether the calculated difference, in other words, the degree of distortion of the waveform of the anomaly detection actual measurement data relative to the waveform of the anomaly detection teacher data, exceeds a predetermined threshold.

Here, if the control unit 30 determines that the degree of distortion does not exceed the threshold value (step S9, NO), it determines that the condition of the ball screw 5 is normal and proceeds to step S10. On the other hand, if the control unit 30 determines that the degree of distortion exceeds the threshold value (step S9, YES), it determines that there is an abnormality in the condition of the ball screw 5 and proceeds to step S11.

In step S10, the control unit 30 sends a display instruction to a predetermined device (e.g., the controller 2 and operation terminal 6) to display that the state of the ball screw 5 is normal. Meanwhile, in step S11, the control unit 30 outputs an abnormality detection signal and sends a display instruction to the above-mentioned device to display that the state of the ball screw 5 is abnormal.

Now, referring again to Figure 3, we will explain the operation of the anomaly detection mode in relation to the deterioration state of the ball screw 5. When the ball screw 5 begins to deteriorate, this affects the input operating waveforms of the electric motor 4 rotational position information p(t), electric motor 4 rotational speed information v(t), and electric motor 4 torque current information iq(t), which differ from the waveforms in normal operation, i.e., the anomaly detection training data acquisition mode, and deteriorate into distorted waveforms with the addition of the above-mentioned minute vibration waves.

Therefore, the control unit 30 compares the abnormality detection training data acquired in the abnormality detection mode with the abnormality detection actual measurement data to calculate the difference in the waveforms (degree of deterioration) (step S8). If the calculated degree of deterioration exceeds a threshold value, it determines that there is an abnormality in the condition of the ball screw 5 (step S9, YES) and outputs this determination result as an abnormality detection signal (step S11).

Users and maintenance personnel of this system can detect or predict abnormal conditions in the ball screw 5 by monitoring whether or not such an abnormality detection signal is output and the display screen of the external device.

However, the software program that executes the above-mentioned abnormality detection function executed by the motor control device 3 must use a different algorithm in order to perform the same abnormality detection when the type of power transmission mechanism through which the power of the electric motor 4 is transmitted is changed.

Specifically, while Figure 1 illustrates an example in which the power transmission mechanism connected to the electric motor 4 is a ball screw 5, there are also cases in which the ball screw 5 is replaced with another power transmission mechanism (for example, a timing belt via gears or the like, not shown).

In other words, in the case of a ball screw 5, the electric motor 4 needs to rotate in both forward and reverse directions to achieve the reciprocating motion described above (see the arrows in Figure 1). In contrast, if the power transmission mechanism is a timing belt, it is sufficient to rotate the electric motor 4 in one direction for the basic operation of moving the workpiece W and delivering it to the downstream device 70. Alternatively, if the linking device or system configuration is significantly changed, it will be necessary to use a different type of power transmission mechanism or downstream device, and in such cases, the operating mode of the electric motor 4 (the control content during basic operation by the electric motor control device 3) will also change.

Thus, if the type of power transmission mechanism (such as basic operation during normal operation) is different, the driving mode of the electric motor 4 will also be different, and the algorithm that controls the rotation of the electric motor 4 during normal operation (basic operation) will also be different. In this case, the normal waveform information obtained as abnormality detection training data will also be different.

On the other hand, the basic method for acquiring the anomaly detection training data and actual measurement data described above, and for comparing these data to determine whether or not an abnormality exists in the power transmission mechanism, can be used in common regardless of the type of power transmission mechanism, etc.

Based on this knowledge, this system is designed to allow the software program to be changed (updated) depending on the type of use, i.e., the type of power transmission mechanism connected to the electric motor 4.

Specifically, the control unit 30 of the motor control device 3 is given the function of an update unit that updates the software programs executed by the motor control device 3, in this example, the programs and data implemented or deployed in the execution memory 33.

In addition, in this embodiment, the control unit 30 is provided with the function of acquiring a software program (management program) having a power transmission mechanism management (abnormality detection) function from an external device (server 10 or controller 2).

<Major Effects of This Embodiment>
According to this embodiment, in which the control unit 30 of the motor control device 3 is provided with the above functions, it becomes possible to perform management such as abnormality detection for various power transmission mechanisms without changing the hardware of the motor control device 3. This makes it possible to improve the performance of the motor control device 3 at low cost. Furthermore, according to this embodiment, it is possible to appropriately and flexibly change the type and arrangement of the power transmission mechanisms and load-side devices (industrial equipment constituting the system) connected to the motor 4 without adding (replacing) the motor control device 3 and controller 2.

(Embodiment 2)
Next, a second embodiment will be described with reference to Fig. 4. Fig. 4 is a flowchart illustrating another example of the processing of an abnormality detection program for diagnosing deterioration of a power transmission mechanism, and shows an algorithm to which an abnormality detection teacher data switching function has been added.

The algorithm shown in Figure 4 is executed, for example, by having the motor control device 3 acquire the abnormality detection program (C) 213 stored in the data storage unit (program library 21) of the controller 2 and launching it in the control unit 30. Note that the same processes as those described above in Figure 2 are given the same step numbers, and explanations will be omitted where appropriate.

The algorithm shown in Figure 4 can be used, for example, during a trial run of the system. Specifically, there may be cases where the waveform of the motor operation information input from the motor 4 and displayed on a specified display unit is judged to be abnormal based on the amplitude value, but there is no distortion (micro-vibration wave) in the waveform, and the current is overcurrent due to a temporary overload when transporting the workpiece W. In such cases, saving the waveform of the motor operation information as training data and using it later can be useful for improving the accuracy of determining whether or not there is an abnormality in the power transmission mechanism.

In step S4A in the teacher data acquisition mode, the control unit 30 derives abnormality detection teacher data by substituting motor operation information (p(t), v(t), iq(t)) into the predetermined function fan3 formula in accordance with the third abnormality detection algorithm (=fan3(formula)). In this teacher data acquisition mode, the same processing as in FIG. 2 is performed, except that the third abnormality detection algorithm (=fan3(formula)) uses a formula different from that of the first abnormality detection algorithm (=fan1(formula)).

In addition, in the abnormality detection mode, the control unit 30 derives training data (step S7A) through processing similar to that of step S4A, and performs the comparison processing of step S8 and the determination processing of step S9, as in the case of FIG. 2. The display processing of step S10 after determining in step S9 that the degree of distortion (degree of waveform degradation) does not exceed the threshold (step S9, NO) is also similar to that of FIG. 2.

On the other hand, if the control unit 30 determines that the degree of distortion (degree of waveform deterioration) exceeds the threshold value (step S9, YES), it proceeds to step S9A. In step S9A, the control unit 30 determines whether a teacher data switching command to switch the teacher data has been input. Here, if the control unit 30 determines that a teacher data switching command has not been input (step S9A, NO), it determines that there is an abnormality in the condition of the ball screw 5, and performs the display processing of step S11, as in the case of Figure 2.

On the other hand, if the control unit 30 determines that a teacher data switching command has been input (step S9A, YES), it determines that the condition of the ball screw 5 is normal and proceeds to step S12. In step S12, the control unit 30 saves the input actual measurement data in the abnormality detection data 333 so that it is added to the teacher data. At this time, the control unit 30 may update the abnormality detection data (322A or 322B) stored in the library memory 32. In addition, the control unit 30 performs a display process to indicate that the condition of the ball screw 5 is normal.

By performing the above processing, for example, the training data can be updated in response to instructions based on operational input from a user monitoring the operation and operating information (waveform) of the system during a test run, which can be useful for improving the accuracy of determining whether or not there is an abnormality in the power transmission mechanism.

(Embodiment 3)
5 and 6 are diagrams illustrating a third embodiment. In the third embodiment, the contents (algorithm) of the motor control program 331 executed by the control unit 30 are configured to be updated or switched as appropriate. From another perspective, in the third embodiment, a plurality of motor control programs are stored in the library memory 32, and the control unit 30 of the motor control device 3 functions as an update unit and updates the motor control programs in the execution memory 33 so that the motor control programs can be selectively executed.

For simplicity, Figure 5 does not show the downstream device 70 that works in conjunction with the electric motor 4, the operation and display unit 36 in the electric motor control device 3, the CPU 20 in the controller 2, etc. Also, to avoid complexity, Figure 5 shows only the electric motor control program 331 stored in the execution memory 33, but in reality, the program that determines whether or not there is an abnormality in the power transmission mechanism described above can also be stored in the execution memory 33 and executed.

Figure 5 is a block diagram showing the configuration of another embodiment of the motor control device, illustrating an example in which the contents (algorithm) of the motor control program to be executed can be updated. In embodiment 3, the position control program, speed control program, and current control program that make up the motor control program 331 shown in Figure 5 are obtained via the communication network (100, 102) directly from server 10 or from server 10 via controller 2.

On the other hand, Figure 6 is a diagram that schematically illustrates a hardware configuration (inverter circuit) that is equivalent to or similar to the program configuration shown in Figure 5.

In the first and second embodiments described with reference to Figures 1 to 4, it is assumed that, during normal operation, the motor control program 331 and the anomaly detection program 332 (i.e., a program that detects abnormalities in the power transmission mechanism using supervised machine learning) separate from the motor control program 331 are executed simultaneously in parallel.

In contrast, Figures 5 and 6 show an example configuration in which the motor control program 331 is executed by the control unit 30 in combination with a position control program for controlling the rotational position of the electric motor 4, a speed control program for controlling the rotational speed of the electric motor 4, and a current control program for controlling the current flowing through the electric motor 4. However, the control unit 30 can also simultaneously execute the program for determining whether or not there is an abnormality in the power transmission mechanism described above in parallel.

First, the contents of the motor control program 331 will be described with reference to Figure 5. Figure 5 schematically shows how the control unit 30 drives the motor 4 by loading and executing the motor control program 331 in the execution memory 33.

As shown in FIG. 5, the motor control program 331 includes a position control program 3311 that controls the position of the motor 4, a speed control program 3312 that controls the speed of the motor 4, and a current control program 3313 that controls the current of the motor 4. Each program (3311, 3312, 3313) can be executed independently of one another by the control unit 30, or can be executed simultaneously in parallel.

In one specific example, the control unit 30 switches the control program (3311, 3312, 3313) to be executed when changing the control method for the electric motor 4. Here, "when changing the control method" includes changing to one of multiple existing control methods (for example, when three control programs (3311, 3312, 3313) are being executed simultaneously and only one of the control programs is executed), or when a new control method is developed.

The following describes the case where a new control method is developed. In the example shown in Figure 5, control programs can also be switched by expanding (updating) one of two types of control programs stored in library memory 32 (position control PG(1) 323A or position control PG(2) 323B, speed control PG(1) 324A or speed control PG(2) 324B, current control PG(1) 325A or current control PG(2) 325B shown in Figure 5) into execution memory 33.

Such program updates can be performed by switching the logical switches (switches 37, 38, and 39 in the example of Figure 6) provided between the library memory 32 and the execution memory 33, as in the case of Figure 1.

In one specific example, the control PGs (323A, 324A, 325A) in Figure 5 (1) are programs that use an existing control method to control the electric motor 4 (rotor position, rotation speed, and amount of current flowing, respectively), and the control PGs (323B, 324B, 325B) in Figure 5 (2) can be programs that use a newly developed control method to control the electric motor 4 (rotor position, rotation speed, and amount of current flowing, respectively).

In another specific example, control PG (323A, 324A, 325A) (1) in Figure 5 can be executed when a ball screw 5 is used as the power transmission mechanism, and control PG (323B, 324B, 325B) (2) can be executed when a timing belt is used as the power transmission mechanism.

Furthermore, as shown in FIG. 5, in addition to the control PGs (1) and (2) (see symbols 231, 232, 241, 242, 251, 252) described above, the controller 2 also stores control PGs (3) (233, 243, 253) as a so-called stock. When the control method is changed as described above, these control PGs (3) (233, 243, 253) are communicated between the controller 2 and the motor control device 3, and are stored in the library memory 32 of the motor control device 3, making them executable by the motor control device 3.

The algorithm for detecting the presence or absence of an abnormality in the power transmission mechanism (ball screw 5, etc.) is as described with reference to Figures 2 to 4. Also, as shown in Figure 5, the server 10 stores the various control programs (control PGs) described above provided to the motor control device 3 or controller 2 in databases as a position control program library group 13, a speed control program library group 14, and a current control program library group 15.

The control of the electric motor 4 by each of the electric motor control programs (3311, 3312, 3313) stored in memory 33 and executed by the control unit 30 will be explained below from a hardware perspective using Figure 6. The electric motor control device 3 manages the position, speed, and torque of the power transmission mechanism and the load side device by feedback-controlling the rotational position and speed of the electric motor 4 using the inverter circuit 122 shown in Figure 6. In addition, through such feedback control and management, it is also possible to detect the presence or absence of an abnormality in the power transmission mechanism described above.

As shown in FIG. 6, the inverter circuit 122 includes a rectifier circuit 123 that converts and rectifies the voltage supplied from the AC power source, and switching elements 124 that switch the voltage values supplied to the three-phase drive motor 4.

Furthermore, as shown in the upper part of Figure 6, the inverter circuit 122 includes a current detector 125 that detects each of the three phase currents flowing through the electric motor 4, a position control unit 126, a speed control unit 127, and a current control unit 128 for controlling the position and speed of the rotor of the electric motor 4 and the current flowing through the electric motor 4.

The inverter circuit 122 also includes a differentiation circuit 129 that calculates the rotor speed of the electric motor 4 and outputs the calculation result to the speed control unit 127, a switching element 130 that switches the signal supplied to the current control unit 128, an oscillation circuit 131 that outputs a standing wave such as a triangular wave, and a PWM circuit 132 that applies pulse width modulation (PWM) to the standing wave and outputs it.

In the example shown in Figure 6, the AC current supplied (input) from the motor control device 3 to the electric motor 4 consists of three phases, Iu, Iv, and Iw, and the current value of each is detected by the current detector 125. The current value id(t) and torque value iq(t) at time t are input from the current detector 125 to the current control unit 128 as actual measured values (feedback information).

Generally speaking, preset control commands for the rotor position and speed are output, for example, from controller 2, and these control commands are input as signals p*(t) and v*(t) to position control unit 126 and speed control unit 127, respectively. Furthermore, a position signal p(t) detected by a position detector 7 attached to the rotating shaft of electric motor 4 is input to position control unit 126, and a rotational speed signal v(t) calculated by differentiation circuit 129 based on this position signal p(t) is input to speed control unit 127.

The position control unit 126 compares the input signals p*(t) and p(t), calculates the difference between them, and outputs the calculated difference to the speed control unit 127. When the switching element 130 is in the first state, i.e., when the signal v*(t) is not input as shown in FIG. 6, the speed control unit 127 outputs the current value signal id*(t) and the torque value signal iq*(t) as control signals to the current control unit 128 based on the difference value input from the position control unit 126 and the rotational speed signal v(t) input from the differentiation circuit 129.

On the other hand, when the switching element 130 is in the second state, i.e., when the speed control command signal v*(t) is input without inputting the difference value output from the position control unit 126, the speed control unit 127 outputs the current value signal id*(t) and the torque value signal iq*(t) as control signals to the current control unit 128 based on the difference between the signal v*(t) and the input signal v(t).

Based on the input signals id*(t) and iq*(t) and signals id(t) and iq(t), the current control unit 128 outputs a three-phase control signal Fm for driving the electric motor 4 to the PWM circuit 132. The PWM circuit 132 PWM-modulates the control signal Fm to generate and output switching signals for switching the state (on/off) of each switch of the switching elements 124 (3 phases x 2 = 6 in the example shown in Figure 6). Thus, changes in the on/off state of the above switches change the amplitude, etc. of each of the three-phase currents supplied to the electric motor 4, thereby performing feedback control of the rotation direction, rotation speed, rotation position, etc. of the rotor of the electric motor 4.

As described above, the control unit 30 of the motor control device 3 functions as an operation control unit that controls the operation of the rotor of the electric motor 4 in accordance with the waveform signal input (feedback) from the electric motor 4, thereby operating the power transmission mechanism (e.g., ball screw 5) in response to the operation of the downstream device 70, which is the load device.

Furthermore, as explained in Figures 3, 5, and 6, when the control unit 30 of the motor control device 3 controls the rotational position of the electric motor 4 by executing the position control program 3311, it functions as a status management unit that manages the status of the power transmission mechanism (detects the presence or absence of abnormalities) based on the waveform signal (rotor position information p(t)) input from the electric motor 4.

In addition, when the control unit 30 controls the rotational speed of the electric motor 4 by executing the speed control program 3312, it functions as a status management unit that manages the status of the power transmission mechanism (detects the presence or absence of abnormalities) based on the waveform signal (rotational speed information v(t)) input from the electric motor 4.

In addition, when the control unit 30 controls the current flowing through the electric motor 4 by executing the current control program 3313, it functions as a status management unit that manages the status of the power transmission mechanism (detects the presence or absence of abnormalities) based on the waveform signal (torque current iq(t)) input from the electric motor 4.

Furthermore, using the functions of the update unit described above, the control unit 30 can selectively read and update each of the programs (3311, 3312, 3313) in memory 33 to be executed from control PG (1) and control PG (2) stored in library memory 32. Therefore, the control unit 30 can combine and use various existing or newly developed control methods as an operation control unit, and can also function as a status management unit that manages the power transmission status (detects the presence or absence of abnormalities).

<Flow of acquiring and updating programs, etc.>
Next, an example of a process flow for acquiring and updating a software function program executable by the control unit 30 of the motor control device 3 will be described with reference to FIG.

In step S41, the control unit 30 of the motor control device 3 controls the external communication unit 31 to connect to the server 10, which is an external device, via the above-mentioned public or industrial communication network (100, 102). The timing of such connection to the server 10 is not particularly limited and can be made at any time, for example. Alternatively, a timer function may be used to connect to the server periodically, for example, during a period after normal operation.

Furthermore, the method for connecting the motor control device 3 and the server 10 is not particularly limited, and the motor control device 3 and the server 10 can be directly connected via the above-mentioned communication networks (100, 102). As another example, a communication connection between the server 10 (10A) and the motor control device 3 can be established via the operation terminal 6 currently connected to the motor control device 3. Alternatively, the controller 2 can be configured to perform the processes of steps S42 to S47, described below, by the user operating the controller 2.

In step S42, the control unit 30 transmits various information related to the industrial equipment, linked equipment, programs, etc. managed by the motor control device 3 to the server 10. Here, the information managed by the motor control device 3 and transmitted to the server 10 includes, for example, the type of motor 4, power transmission mechanism, and load-side device (name, model number, etc.), and the type of software program (e.g., program name) currently implemented (i.e., stored in memory 32, 33). Furthermore, if there are any newly available software programs, the control unit 30 transmits a command to the server 10 to send a list of those programs.

Upon receiving the above information and commands, the server 10 searches for the relevant software program, and if there is no new software program available, it sends a message to that effect to the motor control device 3. In this case, the control unit 30 of the motor control device 3 determines that there is no software program available for acquisition and updating (step S43, NO), terminates the connection with the server 10, and ends the routine in FIG. 7.

On the other hand, if the server 10 finds new software programs available through the above search, it sends a list of the relevant programs to the motor control device 3. In one specific example, the list includes information such as the program name, program functions, and capacity. Here, the program functions include, for example, the details of the upgrade (new functions, corrections, etc.) in the case of an upgraded program.

In this case, the control unit 30 of the motor control device 3 determines that there is a software program that can be acquired and updated (step S43, YES) and proceeds to step S44.

In step S44, the control unit 30 displays a list of the received programs along with selection buttons, and displays a selection screen that allows the user to select a program to acquire. This selection screen can be displayed on the operation display unit 36, or on the display unit of another connected device (controller 2, operation terminal 6).

At this time, the control unit 30 monitors the user's input instructions, and if one or more programs displayed on the selection screen are selected, it acquires (downloads) the selected programs from the server 10 and stores the acquired programs in the library memory 32 (step S45).

When the process of acquiring the program is complete, the control unit 30 terminates the connection with the server 10 and performs a process of displaying an update screen that allows the user to select whether or not to update the program stored in the memory 32 for the next execution (step S46). The update screen can be displayed on the operation display unit 36, as with the selection screen, or on the display unit of another connected device (controller 2, operation terminal 6).

The control unit 30 then monitors the user's input instructions, and if a program to be updated is selected, it reads the selected program from the library memory 32, expands it into the execution memory 33, and replaces the program in the memory 33 (step S47: update processing).

In this way, in each of the above-described embodiments, by providing the control unit 30 of the motor control device 3 with the functionality of an update unit, it becomes possible to perform management such as abnormality detection for various power transmission mechanisms without changing the hardware of the motor control device 3. This makes it possible to improve the performance of the motor control device 3 at low cost. It also makes it possible to flexibly change the layout of industrial equipment that makes up systems such as power transmission mechanisms.

Furthermore, the motor control device 3 in each embodiment is configured to connect to external devices such as the server 10 and controller 2 via the external communication unit 31, and to communicate with external devices to exchange software function programs and data related to those programs, and to compare stored programs, thereby achieving the following effects: That is, the motor control device 3 can obtain necessary programs and data from external devices at any time. In addition, the motor control device 3 can store programs and data that are used less frequently in the controller 2, etc. Furthermore, the motor control device 3 can provide the server 10 with data indicating the operating status of the motor 4 during normal operation of the system, and further analysis on the server 10 side can be used to inspect the status of the power transmission mechanism, etc. from other technical perspectives, or to improve the corresponding software function programs, etc.

The present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those that include all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment.

1 Industrial equipment system (program management system), 2 Controller (external device), 3 Motor control device (power transmission mechanism management device), 4 Electric motor, 5 Ball screw (power transmission mechanism), 6 Operation terminal, 10 Server (external device), 20 CPU (output control unit), 30 Control unit (operation control unit, status management unit, communication control unit, update unit), 31 External communication unit, 32 Memory (for library), 33 Memory (for execution), 70 Downstream device (linked device, load device), 100 Wide area communication network (public communication network), 102 Communication network (industrial communication network), 321A Anomaly detection program (A) (second management program), 321B Anomaly detection program (B) (first management program)

Claims (11)

A power transmission mechanism management device that manages a power transmission mechanism that transmits power from an electric motor to a load-side device in an industrial equipment system in which a plurality of industrial equipment operate in cooperation with each other,
an operation control unit that controls the electric motor to cause the power transmission mechanism to perform a predetermined operation;
a state management unit that executes a first management program and manages the state of the power transmission mechanism based on input information input from the electric motor;
an external communication unit that communicates with an external device to acquire a second management program corresponding to the type of the power transmission mechanism;
an updating unit that replaces the second management program with the first management program and updates the second management program so that the state management unit can execute the second management program;
a library memory for storing a plurality of the second management programs,
the first management program or the second management program is an abnormality detection program for causing the status management unit to determine whether or not there is an abnormality in the power transmission mechanism,
the update unit selectively reads the second management program from the library memory and replaces the first management program in the execution memory with the read second management program;
the external communication unit, when communicating with the external device, outputs to the external device a second management program that has become less frequently used among the second management programs stored in the library memory;
Powertrain management device. 2. The powertrain management device according to claim 1,
the input information is a waveform signal fed back from the electric motor;
the operation control unit controls the operation of the electric motor in response to the waveform signal, thereby operating the power transmission mechanism in accordance with the operation of the load-side device.
Powertrain management device. 2. The powertrain management device according to claim 1,
the state management unit stores the input information as training information in response to an instruction received during execution of the abnormality detection program, and determines whether or not there is an abnormality in the power transmission mechanism using the training information.
Powertrain management device. 2. The powertrain management device according to claim 1,
When the state management unit determines that an abnormality has occurred in the power transmission mechanism, the state management unit outputs an abnormality occurrence signal.
Powertrain management device. 2. The powertrain management device according to claim 1,
the external communication unit outputs the input information to the external device when communicating with the external device.
Powertrain management device. 2. The powertrain management device according to claim 1,
the operation control unit executes a position control program for controlling the rotational position of the electric motor, thereby controlling the electric motor and causing the power transmission mechanism to perform a predetermined operation;
Powertrain management device. 2. The powertrain management device according to claim 1,
the operation control unit executes a speed control program for controlling the rotation speed of the electric motor, thereby controlling the electric motor and causing the power transmission mechanism to perform a predetermined operation;
Powertrain management device. 2. The powertrain management device according to claim 1,
the operation control unit executes a current control program for controlling a current flowing through the electric motor, thereby controlling the electric motor and causing the power transmission mechanism to perform a predetermined operation;
Powertrain management device. 2. The powertrain management device according to claim 1,
the library memory stores a plurality of control programs for causing the operation control unit to control the electric motor;
the update unit updates the control program in the execution memory so that the operation control unit can selectively execute the control program.
Powertrain management device. 2. The powertrain management device according to claim 1,
The external communication unit communicates with the external device via either an industrial communication network or a public communication network.
Powertrain management device. A program management system using the power transmission mechanism management device according to claim 1,
the external device includes a server that supplies the second management program and a controller that outputs a control signal to the powertrain management device to control the electric motor;
the controller includes a storage unit, a communication unit that communicates with the server and the powertrain management device, and an output control unit that outputs the second management program in the storage unit to the library memory of the powertrain management device via the communication unit.
Program management system.