WO2015159457A1

WO2015159457A1 - Control method for motor drive device, motor control system, and program

Info

Publication number: WO2015159457A1
Application number: PCT/JP2014/082365
Authority: WO
Inventors: 義則望月; 晋一角尾; 高橋　一郎
Original assignee: 株式会社日立産機システム
Priority date: 2014-04-16
Filing date: 2014-12-08
Publication date: 2015-10-22
Also published as: JP2015204724A; JP6239434B2

Abstract

The present invention easily and inexpensively achieves a motor control system, ensures real-time performance even in a motor drive device having a small-capacity built-in memory, and makes the synchronized control of a plurality of motors possible. The present invention obtains the usable memory space in a motor drive device and the motor control command execution period, divides the usable memory space by the data size of a control command for transmission to the motor drive device, and by doing so, calculates the number of control commands which can be saved in the motor drive device, determines the control command transmission period for the motor drive device by multiplying the number of savable control commands by the motor control command execution period, and outputs control commands equal to the number of savable control commands to the motor drive device, on the basis of the control command transmission period.

Description

Control method of motor drive device, motor control system and program

The present invention relates to a motor control system including a motor, a motor drive device, and a host device for controlling the motor drive device.

Due to the development of Ethernet (registered trademark) communication technology in the information field, Ethernet (registered trademark) communication technology is also gaining popularity in the FA (Factory Automation) field. For example, a conventional motor control system employs a communication method in which a motor drive device and a host system that controls the motor drive device are connected in parallel and a plurality of data signals are transmitted and received in parallel. By adopting the Ethernet (registered trademark) communication method, it has become possible to reduce wiring and achieve high reliability.

On the other hand, conventional motor control systems that require real-time performance use PLCs (Programmable Logic Controllers) instead of general-purpose PCs (Personal Computers) as a host system that sends motor control control commands to the motor drive. It is common to use. This is because it is difficult for a general-purpose PC to transmit a control command to the motor drive device at a cycle necessary for motor control. For example, while a general motor drive device controls a motor with a cycle of several millimeters, a general-purpose PC can transmit a control command only with a cycle of several tens to several hundreds of millimeters. However, in order to develop an application that operates on a PLC, it is necessary to use ladder logic, which is a kind of programming language. Therefore, compared to the development of an application that operates on a general-purpose PC, it requires a lot of man-hours. There is a problem that becomes expensive. Therefore, from the viewpoint of the ease of system construction and the cost required for system construction, it is desired to realize a motor control system using a general-purpose PC.

As a technology related to motor control systems that require such real-time performance,
A technology for receiving command information from the host system, driving the motor according to the received command information, asynchronously receiving the time information of the host system, and synchronizing the time inside the motor drive device with the received time information Is known (see, for example, Patent Document 1).

JP 2005-237163 A

For example, there is a motor control system that performs synchronous control of a plurality of motors for a long time, such as a belt conveyor. As described above, from the viewpoint of ease of system construction and cost required for system construction, it has been desired to realize a motor control system using a general-purpose PC. From the point of view, it was difficult to realize.

On the other hand, by using the technology described in Patent Document 1, it is conceivable to transmit a control command necessary for a series of motor operations from the host system in a batch without being aware of the real-time performance of the host system. In this case, 100 kbytes to several tens of Mbytes are required as a memory capacity for storing control commands necessary for a series of motor operations received in a batch.

However, from the viewpoint of cost, a general motor drive device can only be equipped with a small capacity memory. Therefore, in a motor control system that performs synchronous control of a plurality of motors such as a belt conveyor, a control command is sent from a host system. It is difficult to configure so as to be transmitted all at once to the motor drive device.

The present invention has been made in view of such circumstances, and realizes a motor control system easily and inexpensively, and synchronizes a plurality of motors while guaranteeing real-time performance even with a motor drive device having a small capacity memory. It is an object to provide a motor control method, a motor control system, and a program that enable control.

A typical example of the present invention is as follows. That is, the present invention is a method for controlling a motor drive device in a control device that controls a plurality of motor drive devices via a network. The control device acquires an available memory capacity in the motor driving device and a motor control command execution cycle by the motor driving device, and stores the acquired usable memory capacity and the motor control command execution cycle in a storage unit. Then, by dividing the available memory capacity stored in the storage unit by the data size of the control command to be transmitted to the motor driving device, the number of storable control commands in the motor driving device is calculated, and the calculated A control command transmission cycle for the motor drive device is determined by multiplying the number of storable control commands in the motor drive device by the motor control command execution cycle stored in the storage unit, and the determined control command Based on the transmission period, the motor drive is provided with the control commands for the number of control commands that can be stored via the network. And transmits to the location.

The motor control system can be realized easily and inexpensively, and even with a small capacity motor drive device, it is possible to control multiple motors while guaranteeing real-time performance.

1 is a diagram illustrating an example of the overall configuration of a motor control system 1. FIG. 2 is a diagram illustrating a configuration example of a control device 100. FIG. 3 is a diagram illustrating a configuration example of a motor driving device 120. FIG. FIG. 3 is a sequence diagram showing an outline of operation of the motor control system 1. It is a figure which shows the example of an operation pattern of the rotation speed of the motor. It is a flowchart which shows the detailed process which produces | generates a control command in the control apparatus. It is a figure which shows the structural example of the control command transmitted to the motor drive device 120 from the control apparatus 100. FIG. FIG. 5 is a flowchart showing processing for transmitting a control command to a motor driving device 120 and processing for receiving a control result message from the motor driving device 120 in the control device 100. FIG. 5 is a flowchart showing a process of transmitting a control command to the motor 130 and a process of transmitting the state of the motor 130 to the control apparatus 100 in the motor drive device 120.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings describing the embodiment of the present invention, the same parts are denoted by the same reference numerals, and repeated description thereof will be omitted.

FIG. 1 is a diagram showing an example of the overall configuration of a motor control system 1 according to an embodiment of the present invention. In the motor control system 1, the control device 100, which is a host device in the motor control system 1, is connected to a plurality of motor driving devices 120 via a network such as a wired LAN (Local Area Network) via the HUB 140 and the like. The control device 100 and each motor driving device 120 may be connected by a serial cable or a wireless LAN. A motor 130 is connected to each motor driving device 120. The control device 100 generates a control command corresponding to the motor rotational speed necessary for controlling the motor 130 and transmits the control command to each motor driving device 120. The motor driving device 120 controls the rotation speed of the motor 130 by changing the power supply frequency. As the motor control system 1 having such a configuration, for example, a belt conveyor, a winding device, or the like is applicable.

FIG. 2A is a diagram illustrating a configuration example of the control device 100.

The control device 100 according to the present embodiment is realized using a general-purpose PC. As shown in FIG. 2A, the control device 100 according to the present embodiment includes a hardware module 200, an OS (Operating System) 210, and a software module 220.

The hardware module 200 is hardware necessary for operating the control device 100, and includes a CPU (Central Processing Unit), a volatile memory, a nonvolatile memory, a storage device, a display unit such as a display, and an input unit such as a keyboard. , An interface for connecting an external storage medium such as a USB memory, and a communication interface for performing data communication with the motor driving device 120.

The OS 210 is basic software that comprehensively controls the operation of the control device 100.

The software module 220 is software (computer program) necessary for controlling the motor driving device 120, and includes a control command generation function 222, a control result display function 224, a control command transmission function 226, a parameter setting function 228, and a time synchronization function. 230, and a network status monitoring function 232 is included. These software are executed by the CPU.

The control command generation function 222 is a function for generating a control command for the motor driving device 120 to control the motor 130.

The control result display function 224 receives a message including information indicating the current operation state of the motor 130, which is a result of controlling the motor 130, from the motor driving device 120, analyzes the received message, It is a function which displays the information which shows the operation state of this motor 130 on a display part. The user can confirm the operation state of the motor 130 displayed on the display unit, and can regenerate control commands and reset operation parameters of the motor driving device 120 as necessary.

The control command transmission function 226 is a function for transmitting the control command generated by the control command generation function 222 to each motor driving device 120 via the network.

The parameter setting function 228 is a function for transmitting parameters necessary for operating the motor drive device 120, such as upper / lower frequency, acceleration / deceleration time, base frequency, etc., to each motor drive device 120 via the network. .

The time synchronization function 230 is a function for performing time synchronization with each motor drive device 120 via a network. As a method for performing time synchronization, a protocol based on SNTP (Simple Network Time Protocol) or IEEE 1588 is used.

The network state monitoring function 232 is a function for monitoring the state of the network by acquiring a message flowing on the network and periodically calculating the traffic amount.

FIG. 2B is a diagram illustrating a configuration example of the motor driving device 120.

The motor driving device 120 includes a hardware module 250, an OS 210, and a software module 270.

The hardware module 250 is hardware necessary for operating the motor driving device 120, and includes a microcomputer 252, an external communication unit 254, a control command storage unit 256, an external I / O 258, and a clock 260.

The microcomputer 252 is a module including a CPU, a ROM (Read Only Memory), a RAM (Random Access Memory), and a nonvolatile memory.

The external communication unit 254 is an interface for performing data communication with the control device 100, and corresponds to an interface such as Ethernet (registered trademark), serial cable, or wireless. *

The control command storage unit 256 is a module that stores a control command received from the control device 100 via the external communication unit 254, and includes a volatile memory, a nonvolatile memory, a HDD (Hard Disk Drive), and an SSD (Solid State Drive). Such a storage device is applicable.

External I / O 258 is an interface for controlling the rotation speed of the motor 130, and corresponds to analog I / O, digital I / O, and the like.

The clock 260 is a module that records the time of the motor driving device 120.

The software module 270 is software (computer program) necessary for data communication with the control device 100 and control of the motor 130. The software module 270 includes a control command reception function 272, a motor control function 274, an operation result transmission function 276, and a time synchronization function 230. Including.

The control command receiving function 272 is a function that receives a control command from the control device 100 via the external communication unit 254 and stores the received control command in the control storage unit 256.

The motor control function 274 is a function for controlling the motor 130 via the external I / O 258 based on a control command stored in the control storage unit 256. These software are executed by a microcomputer.

The operation result transmission function 276 is a function of transmitting the state of the motor 130 acquired through the external I / O 258, for example, the rotational speed to the control device 100 through the external communication unit 254. *

FIG. 3 is a sequence diagram showing an outline of the operation of the motor control system 1. Here, the motor control system 1 is activated when the power supply of the control device 100 and each motor drive device 120 is activated.

First, when the motor control system 1 is activated, the time synchronization function 230 provided in each of the control device 100 and the motor drive device 120 causes the time of the timepiece 260 mounted in the motor drive device 120 and the timepiece of the timepiece provided in the control device 100. A process for synchronizing the time is performed (step S300).

After the time synchronization process is performed, the control device 100 generates operation pattern information indicating a change in the rotation speed of the motor 130 for each time as illustrated in FIG. 4 in accordance with a user operation (step S302). Software such as EXCEL (registered trademark) is used when generating the operation pattern information of the motor rotation speed. Although an operation pattern as shown in FIG. 4 may be created using PLC, it is necessary to use ladder logic. Ladder logic development requires a large number of man-hours as compared with the case where development is performed using EXCEL (registered trademark) or the like. Furthermore, when changing the operation pattern of the motor rotation number, if EXCEL (registered trademark) is used, it is only necessary to change the corresponding value. However, if ladder logic is used, it is necessary to perform programming again. The change also requires a great amount of man-hours. In the present embodiment, the operation pattern information of the motor rotational speed is generated and changed using software such as EXCEL (registered trademark), so that the motor control system 1 can be operated efficiently, and the motor control is performed. The system 1 can be realized simply and inexpensively.

After generating the operation pattern information, the control device 100 generates a control command for controlling the motor 130 by the control command generation function 222 (step S304).

Next, the control device 100 transmits the control command for controlling the motor 130 generated by the control command generation function 222 to each motor drive device 120 via the network by the control command transmission function 226 (steps S306 and S308).

Next, the control device 100 receives a message indicating the current operation state of the motor 130 as a control result of the motor 130 from each motor driving device 120 by the control result display function 224, and displays it on the display unit. (Step S310, Step S312, Step S314).

FIG. 5 is a flowchart showing a detailed process in the control device 100 for generating a control command (FIG. 3_Step S304).

First, the control device 100 generates a motor drive device information acquisition request message and transmits it to each motor drive device 120 via a communication interface built in the hardware module 200 (step S500). Each motor drive device 120 that has received the motor drive device information acquisition request message, the control command execution cycle in which each motor drive device 120 controls the motor 130, the available memory capacity in each motor drive device 120, and each motor drive device A response message including information related to the motor drive device 120 such as the model number is generated and transmitted to the control device 100 via the external communication unit 254.

Next, the control device 100 determines whether or not a response message has been received from the motor drive device 120 (step S502).

When the response message is not received from the motor drive device 120 (NO in step S502), for example, the control device 100 displays an error message on the display unit and notifies the user that the response message is not received (step S520). If a response message is not received even after a predetermined time has elapsed, the motor drive device information acquisition request message may be retransmitted.

On the other hand, when the response message is received (YES in step S502), the control device 100 stores the information regarding the motor drive device 120 included in the response message in a storage unit such as a volatile memory, and the use stored in the storage unit. By dividing the possible memory capacity by the data size of the control command, the number of control commands (number of storable control commands) that can be stored in the motor drive device 120 is calculated (step S504). For example, when the available memory capacity is 2 kBytes and the data size of the control command is 2 Bytes, the number of control commands that can be stored in the motor drive device 120 is 1000 (2 kBytes / 2 Bytes).

Next, the control device 100 multiplies the number of storable control commands calculated in step S504 by the control command execution cycle of the motor 130 stored in the storage unit, so that the control device 100 sends a control command to the motor drive device 120. A transmission cycle (control command transmission cycle) is calculated (step S506). For example, when the control command execution cycle is 2 ms, the control device 100 transmits 1000 control commands to the motor drive device 120 via the network at a cycle of 2 seconds (2 ms × 1000).

The control device 100 checks whether or not the control command transmission cycles of all the motor drive devices 120 have been calculated (step S508). If not calculated (NO in step S508), the control device 100 returns to step S500.

When the control device 100 calculates the control command transmission cycle for all the motor drive devices 120 that perform control (YES in step S508), the number of storable control commands calculated in step S504, the data size of one control command, From the number of motor drive devices connected to the control device 100 via the network, a communication band necessary for transmitting a control command to each motor drive device 120 is calculated (step S510). For example, when there are 30 motor drive devices 120 and the control device 100 transmits 1000 control commands to each motor drive device 120 in a cycle of 2 seconds, the communication bandwidth required for the transmission is 480 bps (1000 × 2 bytes × 8 × 30).

Next, the control device 100 compares the calculated communication band with a predetermined available communication band. If the available communication band is wider than the calculated communication band (YES in step S512), the control apparatus 100 uses the calculated communication band. Since communication is possible, a control command is generated for each motor drive device 120 based on the values calculated in steps S504 and S506, and stored in a volatile memory or a storage device (step S518).

Thus, in the present embodiment, paying attention to the available memory capacity for each motor driving device 120 and the period in which each motor driving device 120 controls the motor 130, the control device 100 controls the motor driving device from each motor driving device 120. Information including the available memory capacity in 120 and the control period of the motor 130 by the motor driving device 120 is acquired, and the control command is transmitted to the motor driving device 120 using the information and the data size information of the control command. The control command transmission cycle is determined, and the control command can be transmitted to each motor drive device 120 according to the determined control command transmission cycle. As a result, the motor control system 1 can be realized using a general-purpose PC whose real-time performance is inferior to that of the motor drive device 120, and even in the motor drive device 120 having a small usable memory capacity, the real-time performance is guaranteed and the plurality of motors 130 Synchronous control is possible. This embodiment is particularly suitable for a motor control system that performs synchronous control of a plurality of motors for a long time. In addition, the motor control system 1 according to the present embodiment can be realized with fewer man-hours and at a lower cost than a motor control system using a PLC.

In the above description, the method for transmitting the motor drive device information acquisition request message to the motor drive device 120 has been described as an example of the method for acquiring information related to the motor drive device 120. However, the motor drive device information acquisition request message is transmitted. As a method other than the above, information related to each motor driving device 120 is included in a setting file in which information necessary for system construction generated by the user is collected, and stored in an external storage medium. A method of acquiring information related to each motor driving device 120 by reading this setting file from the external storage medium at the time of power activation may be used. Alternatively, the control instruction execution cycle may be acquired from a setting file, and the available memory capacity may be acquired using a motor drive device information acquisition request message. In addition, a setting file including information about each motor driving device 120 is created using the input unit, stored in a storage unit such as an internal memory, and the setting file is read from the storage unit, whereby information regarding each motor driving device 120 is obtained. It doesn't matter how you get it.

FIG. 6 is a diagram illustrating a configuration example of a control command transmitted from the control device 100 to the motor driving device 120. As shown in FIG. 6, the format of the control command generated for each motor driving device 120 by the control device 100 is obtained by adding the time 602 for executing the control command 602 to the control command 600. Here, in the synchronous control of the plurality of motors 130, the cycle for executing the control command 600 may be different for each motor 130. For example, in the case of the prior art in which only the execution start time for executing the control command 600 is transmitted, it is necessary to set the execution cycle of the control command 600 for each motor 130 in advance. Therefore, for example, when performing synchronous control of several tens to several hundreds of motors 130, it takes a lot of time to set the cycles of these motors 130. In the present embodiment, the control device 100 adds the time 602 to the control command 600 and transmits it, so that the motor drive device 120 that has received this can check the value of the time 602. It is not necessary to set the cycle for each motor 130 in advance. The time 602 may be an absolute time or a relative time. When the time 602 is a relative time, the control command that is transmitted to the motor drive device 120 from the control device 100 is based on the control command with the oldest time.

Returning to FIG. 5, when the available communication band is narrower than the calculated control command transmission communication band (NO in step S512), it is difficult to perform communication in the calculated control command transmission communication band. It is necessary to narrow the communication band necessary for transmitting the control command. Therefore, in the present embodiment, when the available communication bandwidth is narrower than the calculated control command transmission communication bandwidth, the control device 100 determines whether or not the number of storable control commands can be changed (step S514) and can be changed. In such a case, control is performed to change the number of control commands that can be stored (step S516).

If the number of storable control instructions can be changed (YES in step S514), the control device 100 returns to step S510 after changing the number of storable control instructions. On the other hand, when the number of storable control instructions cannot be changed (NO in step S514), the control device 100 displays an error message on the display unit and notifies the user (step S520). In step S516, if the number of control commands that can be stored is too small, the control command transmission cycle is shortened, and it becomes difficult to perform synchronous control of the plurality of motors 130 while ensuring real-time performance. Therefore, in the present embodiment, the control command transmission cycle that can be realized by the control device 100 is measured in advance, and the measurement result is set to the lower limit value of the control command transmission cycle. The number of control commands that can be saved was changed. Although not shown, if the control command transmission cycle exceeds the lower limit value, it is difficult to implement the control device 100 with a general-purpose PC. For example, it is difficult to construct a system. A message indicating this may be displayed on the display unit to notify the user.

In the present embodiment, a motor control system that uses tens or hundreds of motor driving devices 120 by using a mechanism for changing the number of control commands that can be stored in consideration of the communication bandwidth for transmitting control commands in this way. The present embodiment can also be applied. Further, for example, the present embodiment can be applied to a communication interface having a narrow communication band as compared with Ethernet (registered trademark) such as serial communication and wireless communication.

FIG. 7 is a flowchart showing processing for transmitting a control command to the motor driving device 120 and processing for receiving a control result message from the motor driving device 120 in the control device 100. The processing shown in FIG. 7 is executed by the control result display function 224, the control command transmission function 226, and the network state monitoring function 232.

Based on the control command transmission cycle calculated in step S506 (FIG. 5), the control device 100 sends the control commands for the number of storable control commands calculated in step S504 via the communication interface built in the hardware module 200. To the motor drive device 120. Therefore, the control device 100 first determines whether it is time to transmit a control command to the motor drive device 120 based on the control command transmission cycle and the number of storable control commands (step S700). *

When it is time to transmit a control command to the motor drive device 120 (YES in step S700), the control device 100 transmits the control command to the motor drive device 120 via the communication interface built in the hardware module 200 ( Step S702).

Next, the control device 100 determines whether or not a response message (ACK) has been received from the motor drive device 120 (step S704). When the response message (ACK) is received (YES in step S704), the control device 100 determines that the control command has been successfully transmitted, and returns to step S700.

On the other hand, if the response message is not received (NO in step S704), the control device 100 determines that some abnormality has occurred in the motor control system 1, and urgently stops the operation of the motor control system 1. An emergency stop message is transmitted to the motor drive device 120 (step S716), and a message to that effect is displayed on the display unit to notify the user (step S718). Although not shown, even when the received response message includes an error code, the control device 100 transmits an emergency stop message to the other motor drive device 120 (step S716), to that effect. An error message is displayed on the display unit and notified to the user (step S718).

As described above, in the present embodiment, the mechanism for transmitting the emergency stop message is installed in the motor control system 1 so that the operation of the motor control system 1 is emergency stopped when any one of the motor driving devices 120 is abnormal. As a result, runaway of the motor control system 1 can be prevented. However, if the operation of the motor 130 is suddenly stopped, the motor control system 1 may be in a more dangerous state. Therefore, a safety stop function such as slowing down the rotation speed of the motor 130 to stop the operation of the motor 130, etc. By using this, the operation of the motor control system 1 can be safely stopped. For example, in a belt conveyor system that operates with a plurality of motors, it is possible to prevent the danger that the operation of the belt conveyor is disturbed due to a failure of a certain motor and the work on the belt conveyor falls. In addition, since the timing for transmitting the emergency stop message varies depending on the system, for example, when there is no response message from a plurality of motor drive devices 120 or when a response message from the motor drive device 120 is not received multiple times, A stop message may be transmitted.

Returning to FIG. 7, if it is not time to transmit a control command to the motor drive device 120 (NO in step S700), the control device 100 operates the current motor 130 as a result of controlling the motor 130 by the motor drive device 120. It is determined whether or not a message including information indicating the state is received (step S706).

If the control result message is received (YES in step S706), the control device 100 analyzes the control result message, displays the operation state of the motor 130 on the display unit (step S708), and returns to step S700. As a result of analyzing the control result message, if the operation state of the motor 130 deviates from the operation pattern generated in step S302 (FIG. 3), the control device 100 has an abnormality in the motor control system 1. The emergency stop message may be transmitted to the motor drive device 120. In this case, in addition to transmitting an emergency stop message to the motor drive device 120, operation pattern information is generated again using the analysis result, and the value of the control command 600 shown in FIG. 6 is changed. good.

If the control result message has not been received (NO in step S706), the control device 100 determines whether an emergency stop message has been received from the motor drive device 120 (step S710).

If an emergency stop message has been received (YES in step S710), control device 100 transmits an emergency stop message to another motor drive device 120 (step S716), and an error message to that effect is displayed on the display unit. The information is displayed and notified to the user (step S718).

On the other hand, when the emergency stop message has not been received (NO in step S710), the control device 100 confirms the current network state such as the current communication band by the network state monitoring function 232 (step S712).

Next, the control device 100 compares the current communication band with the control command transmission communication band calculated in step S510 (FIG. 5) (step S714). As a result, if the current communication band is narrower than the control command transmission communication band (YES in step S714), the control command may not be transmitted to the motor driving device 120 normally. In order to make an emergency stop, the control device 100 transmits an emergency stop message to the other motor drive device 120 (step S716), displays that fact as an error message on the display unit, and notifies the user (step S718).

On the other hand, if the current communication band is wider than the control command transmission communication band (NO in step S714), the process returns to step S700.

FIG. 8 is a flowchart showing processing for transmitting a control command to the motor 130 and processing for transmitting the state of the motor 130 to the control device 100 in the motor driving device 120. The processing shown in FIG. 8 is executed by the control command reception function 272, the motor control function 274, and the operation result transmission function 276.

First, the motor driving device 120 refers to the control command stored in the control command storage unit 256, and determines whether or not it is time to transmit the control command to the motor 130 (step S800).

In the case of a timing for transmitting a control command to the motor 130 (YES in step S800), the motor driving device 120 changes the control command to an electrical signal (analog signal) according to the interface of the motor 130, and then changes the external I / O 258. To the motor 130 (step S802). In addition, the motor drive device 120 acquires information indicating the state of the motor 130 from the motor 130 being controlled (step S804).

Next, the motor drive device 120 determines whether or not the operation of the motor 130 is normal based on the acquired state information of the motor 130 (step S806).

If the motor 130 is operating normally (YES in step S806), a control result message including information indicating the state is generated and transmitted to the control device 100 via the external communication unit 254 (step S808). ), The process returns to step S800.

On the other hand, if the motor 130 is not operating normally (NO in step S808), it is determined that an abnormality has occurred in the motor control system 1, an emergency stop message is generated, and the generated emergency stop message is transmitted to the external communication unit. The data is transmitted to the control device 100 via the H.254 (step S810).

If it is not the timing for transmitting a control command to the motor 130 (NO in step S800), the motor drive device 120 determines whether or not a control command has been received from the control device 100 (step S812).

If a control command has been received (YES in step S812), the received control command is stored in the control command storage unit 256 (step S814), a response message is generated, and the control device 100 is connected via the external communication unit 254. (Step S816).

On the other hand, when the control command is not received (NO in step S812), the motor drive device 120 determines whether or not an emergency stop message is received from the control device 100 (step S818).

If an emergency stop message has been received (YES in step S818), the motor drive device 20 performs control to stop the operation of the motor 130 via the external I / O 258 (step S820).

On the other hand, when the emergency stop message has not been received (NO in step S818), the motor drive device 120 returns to step 800.

The embodiment of the present invention has been specifically described above. However, the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention.

According to the present embodiment, the motor control system 1 can be realized simply and inexpensively, and a plurality of motors can be synchronously controlled while guaranteeing real-time performance even with a motor drive device having a small memory capacity.

DESCRIPTION OF SYMBOLS 100 ... Control apparatus, 120 ... Motor drive device, 130 ... Motor, 140 ... HUB, 200, 250 ... Hardware module, 210 ... OS, 220, 270 ... Software module.

Claims

A control method of a motor drive device in a control device that controls a plurality of motor drive devices via a network,
Obtaining an available memory capacity in the motor driving device and a motor control command execution cycle by the motor driving device;
Storing the obtained usable memory capacity and the control instruction execution cycle of the motor in a storage unit;
By dividing the available memory capacity stored in the storage unit by the data size of the control command transmitted to the motor drive device, the number of storable control commands in the motor drive device is calculated,
By multiplying the calculated number of control commands that can be stored in the motor drive device and the control command execution cycle of the motor stored in the storage unit, a control command transmission cycle for the motor drive device is determined,
Based on the determined control command transmission cycle, the control commands for the number of control commands that can be stored are transmitted to the motor drive device via the network.
A control method for a motor drive device.
The control instruction is added with time information for executing the control instruction.
The method for controlling a motor drive device according to claim 1.
By the control device,
From the number of control commands that can be stored, the data size of one control command, and the number of motor drive devices connected to the control device, a communication bandwidth for transmitting control commands on the network is calculated,
Using the calculated communication band for control command transmission on the network, the control commands for the number of storable control commands are transmitted to the motor driving device.
The method for controlling a motor driving device according to claim 2.
By the control device,
When the calculated communication band for control command transmission is narrower than a predetermined available communication band, based on the determined control command transmission period, the calculated communication band for control command transmission on the network is used for the storage. Transmitting control commands for the number of possible control commands to the motor drive device;
The method for controlling a motor driving device according to claim 3.
By the control device,
When the calculated communication bandwidth for transmitting the control command is wider than a predetermined available communication bandwidth, the number of storable control commands is changed, and the control command transmission on the network is changed based on the changed number of storable control commands. Recalculate the trusted communication bandwidth,
The method for controlling a motor driving device according to claim 3.
By the control device,
When there is no response to the transmission of the control command from the motor drive device, an emergency stop message is transmitted via the network to each motor drive device other than the motor drive device without the response.
The method for controlling a motor driving device according to any one of claims 1 to 5, wherein:
By the control device,
Receiving a motor control result from the motor driving device via the network, and displaying the result on a display unit;
The method for controlling a motor driving device according to claim 6.
By the control device,
When an emergency stop message is received without receiving the motor control result from any of the motor drive devices, an emergency is made via the network to each motor drive device other than the motor drive device that is the source of the emergency stop message. Send a stop message,
The method for controlling a motor driving device according to claim 7.
By the control device,
The method for controlling a motor drive device according to claim 8, wherein when the motor control result and the emergency stop message are not received from any of the motor drive devices, a network state is confirmed.
A motor control system including a plurality of motor drive devices and a control device that controls the plurality of motor drive devices via a network,
The controller is
Means for obtaining an available memory capacity in the motor driving device and a control command execution cycle of the motor by the motor driving device;
Means for storing the acquired available memory capacity and the control instruction execution cycle of the motor in a storage unit;
Means for calculating the number of control commands that can be stored in the motor drive device by dividing the available memory capacity stored in the storage unit by the data size of a control command transmitted to the motor drive device;
Means for determining a control command transmission cycle for the motor drive device by multiplying the calculated number of control commands that can be stored in the motor drive device by a control command execution cycle of the motor stored in the storage unit;
Based on the determined control command transmission cycle, there is means for transmitting control commands for the number of storable control commands to the motor drive device via the network,
The motor driving device is
Means for receiving the control command from the control device;
Means for controlling the motor based on the received control command;
A motor control system characterized by that.
The motor drive device acquires status information of the motor, and when the motor is not operating normally, determines that an abnormality has occurred in the motor control system and sends an emergency stop message to the control device in the network. The motor control system according to claim 10, further comprising a means for transmitting via.
On the computer,
A process for obtaining an available memory capacity in the motor driving device and a motor control command execution cycle by the motor driving device;
A process of storing the acquired available memory capacity and the control instruction execution cycle of the motor in a storage unit;
A process of calculating the number of control commands that can be stored in the motor drive device by dividing the available memory capacity stored in the storage unit by the data size of a control command transmitted to the motor drive device;
A process of determining a control command transmission cycle for the motor drive device by multiplying the calculated number of control commands that can be stored in the motor drive device by a control command execution cycle of the motor stored in the storage unit;
Based on the determined control command transmission period, a process of outputting control commands for the number of control commands that can be stored to the motor drive device;
A program characterized by having executed.