JP2006050774A - Motor drive system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the number of wirings and cost of an FA network system by operating a host system, a motor driving device, and a serial encoder synchronously and by sharing various kinds of data. <P>SOLUTION: This motor drive system comprises the host system 1 provided with a command generating portion 11 and a serial communications portion 12, the motor driving device 2 provided with a motor control device 21 and a serial communications portion 22, the serial encoder 3 provided with a motor state detecting portion 31 and a serial communications portion 32, and a motor 4. The serial communications portions 12, 22, 32 of the host system 1, the motor driving device 2, and the serial encoder 3 respectively are connected to a same channel 5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a motor drive system connected by serial communication.

  The development of serial communication technology represented by the Internet is deeply penetrating into the FA field, and there are examples of wire-saving and high-reliability by transferring analog information and replacing multiple digital signals with serial communication. is increasing.

  For example, there is a method in which a conventional parallel wiring of digital / analog / pulse signal mixture is reduced by connecting a host system and a motor driving device by serial communication (for example, see Patent Document 1).

  In addition, serial encoders having a serial communication function are becoming mainstream between motor driving devices and motors as the resolution of encoders as motor position detection means increases. A method of connecting a plurality of serial encoders to one bus line has also been proposed. In this case, a further wire saving effect can be obtained (for example, see Patent Document 2).

Furthermore, by returning the signal from the conventional parallel encoder as it is to the host system, the host system acquires the motor position information and replaces it with a serial encoder for the purpose of detecting abnormalities in the motor drive device. There is also a method for aiming at the same effect (for example, see Patent Document 3).
Japanese Patent Laid-Open No. 10-326107 JP-A-8-233599 JP 2002-341944 A

  The above-mentioned conventional essential problem is that a plurality of serial communication methods are mixed among the host system, the motor drive device, and the serial encoder. This is because the host system side has a large capacity and low speed, and the serial encoder side has a small capacity and high speed, and the amount of data to be exchanged and the control cycle are different. This is due to the development of communication systems.

  As an example of this adverse effect, the motor drive device located in the middle needs to have two different types of serial communication means for the host system and the serial encoder. Further, in order to synchronize the position command from the host system and the position control of the motor, a highly accurate synchronizing means is required. In addition, when the position information of the serial encoder is monitored by the host system, a delay is likely to occur. Furthermore, there are various problems such as the need for synchronization means similar to the position command even if direct serial encoder communication is connected to the host system.

  The present invention solves the above-described conventional problems, and synchronizes the host system, the motor drive device, and the serial encoder to realize sharing of various information, thereby reducing the wiring and cost of the FA network system. For the purpose.

In order to solve the above problems, the present invention includes a host system including a command generation unit and a serial communication unit, a motor drive device including a motor control unit and a serial communication unit, a motor state detection unit, and a serial communication unit. The serial encoder includes a serial encoder and a motor. The serial communication units of the host system, the motor drive device, and the serial encoder are connected to the same communication path.

  Further, the motor drive device starts the operation of the motor control unit in synchronization with the command information transmitted from the host system, and the serial encoder latches the motor information of the motor state detection unit in synchronization with the command information. Then, transmission of motor information is started.

  The motor drive device transmits status information after the serial encoder receives the motor information.

  Also, the serial encoder transmits status information after the motor information transmission of the serial encoder is completed.

  The host system transmits status information after the serial encoder motor information is received.

  The motor drive system connects one host system, a plurality of sets of motor drive devices, and a serial encoder to the same communication path.

  Further, the motor drive system connects a plurality of host systems, a plurality of sets of motor drive devices, and a serial encoder to the same communication path.

  According to the motor drive device of the present invention, the host system, the motor drive device, and the serial encoder all have only one serial communication unit, the number of communication ports can be reduced, connection cables, connectors, communication dedicated hardware, etc. Hardware costs can be reduced by sharing the hardware. In addition, the burden of software development for controlling them is reduced.

  In addition, this network configuration makes it possible to easily realize complete synchronization between the command information from the host system and the motor information of the serial encoder. Further, not only the motor drive unit but also the host system receives the motor information at the same time. Information can be accurately monitored.

  In addition, by sending status information other than command information and motor information of the motor drive device, serial encoder, and host system in an appropriate order after receiving the motor information of the serial encoder, the host system, motor drive device, and serial encoder Can share all necessary information with each other.

  Also, if one host system, multiple sets of motor drive units and serial encoders are connected to the same communication path, a larger hardware is required than if one set of motor drive units and serial encoders are connected to the same communication path. Hardware costs and software development costs can be reduced.

  Furthermore, by having a plurality of host systems, even if one of the host systems shuts down, another host system sharing the same information can take over control. Further, if a plurality of higher systems share the generation of command information, it is possible to reduce the burden on the processing capacity of each higher system.

  One or more host systems including a command generation unit and a serial communication unit, one or more motor drive devices including a motor control unit and a serial communication unit, a motor state detection unit, and a serial communication unit In a motor drive system composed of one or more serial encoders and one or more motors, all host systems, motor drive devices, and serial communication units of the serial encoder are connected to the same communication path.

  In synchronization with the command information transmitted from any of the host systems, the plurality of motor drive devices start the operation of the motor control unit, and at the same time, the plurality of serial encoders latch the motor information of the motor state detection unit. Thereafter, the plurality of serial encoders start transmitting motor information in a predetermined order. After all the serial encoders have finished transmitting motor information, the host system, the motor drive device, and the serial encoder transmit status information in a predetermined order.

  The plurality of host systems share the command generation process, or have a role as the other backup.

  In the block diagram of FIG. 1, the host system 1 includes a command generation unit 11 and a serial communication unit 12, the motor drive device 2 includes a motor control unit 21 and a serial communication unit 22, and the serial encoder 3 includes a motor state detection unit 31 and A serial communication unit 32 is provided.

  The motor 4 is controlled by the motor control unit 21, and the result is detected by the motor state detection unit 31.

  In this configuration, the serial communication unit 12, the serial communication unit 22, and the serial communication unit 32 are all connected to the same communication path 5, so that the host system 1, the motor driving device 2, and the serial encoder 3 each have one serial communication unit. All that is required is to reduce the number of communication ports.

  In addition, since the connection cables, connectors, dedicated communication hardware, communication control software, etc. can all be shared, development costs can be greatly reduced.

  As the communication path 5, it is optimal to use hardware for bus connection such as RS485 that can be simultaneously transmitted to all connected devices, but 10BASE2 that can also be connected to the bus by Ethernet (registered trademark). Or 10BASE5 may be used. Also, if simultaneous transmission to all devices is possible with negligible transmission delay with respect to the communication period, there is no problem even if the ring method or the tree method is used. It is also possible to extend the communication distance with a repeater hub. The FA field-specific serial communication technology is also improving day by day, and now FA networks with a communication speed of 100 Mbps are commercialized. It can be said that the communication capacity is still too much by integrating these.

  The flow of information in FIG. 1 will be described with reference to the time chart of FIG.

The host system 1 transmits the command information 14 to the communication path 5 by the command generation process 13 in the command generation unit 11. The motor drive device 2 and the serial encoder 3 simultaneously receive this command information 14 and start processing individually. The motor driving device 2 starts a motor control process 23 in the motor control unit 21. The serial encoder 3 stores the state of the motor 4 as the motor information 34 in the motor state detection processing 33 by the motor state detection unit, and transmits this to the communication path 5. The motor control process 23 that has already started the process related to the command information 14 receives the motor information 34 and performs the remaining control processes.

  Although not shown in FIG. 2, the motor control unit 21 in FIG. 1 controls the motor 4 based on the result of the motor control process 23.

  With this configuration, complete synchronization between the command information from the host system and the motor information of the serial encoder can be easily realized. In addition, since the motor information is received not only by the motor drive device but also by the host system, the motor information in the host system can be accurately monitored at the same time.

  In the time chart of FIG. 3, the motor drive device 2 starts the status generation process 25 after the motor control process 23 ends, and transmits the status information 26 to the communication path 5 after the motor information 34.

  Thereby, various information of the motor control device 2 is transmitted to the host system 1 and the serial encoder 3 so that information can be shared.

  In the time chart of FIG. 4, the serial encoder 3 starts the status generation process 35 after the motor state detection 33, and transmits the status information 36 to the communication path 5 after the motor information 34.

  As a result, various information of the serial encoder 3 is transmitted to the host system 1 and the motor drive device 2 so that the information can be shared.

  In the time chart of FIG. 5, after receiving the motor information 34, the host system 1 starts the status generation process 15 and transmits the status information 16 to the communication path 5.

  As a result, various information of the host system 1 is transmitted to the motor drive device 2 and the serial encoder 3 so that the information can be shared.

  The block diagram of FIG. 6 shows a system configuration using a plurality of motor control devices 2a, a motor control device 2b and a serial encoder 3a, a serial encoder 3b, a motor 4a, and a motor 4b.

  The time chart of FIG. 7 shows the flow of information at this time. The difference from FIG. 2 is that the serial encoder 3a, the motor information output determination process 37a of the serial encoder 3b, and the motor information output determination process 37b It is in the point which controls the timing which outputs own motor information 34a and motor information 34b. As a result, the motor control processing 23a and the motor control processing 23b for a plurality of axes can be executed synchronously.

  In the block diagram of FIG. 8, in addition to FIG. 6, a plurality of host systems 1a and host systems 1b are connected.

The time chart of FIG. 9 shows the flow of information at this time. The difference from FIG. 7 is that the host system 1a and the host system 1b execute the command generation process 13a and the command generation process 13b alternately, and the command information 14a. The command information 14 b is transmitted to the communication path 5.

  As a result, the load on the host system 1a and host system 1b can be halved, and the cost can be reduced. Further, the host system 1a and the host system 1b may be in a master-slave relationship, and the slave host system may take over the command generation process when an abnormality occurs in the master host system.

  The motor drive system of the present invention can realize synchronization with command information of the host system, motor drive device, and serial encoder and sharing of various information in one serial communication network. Down can be realized.

  It goes without saying that a similar system can be constructed by connecting an I / O module or various sensors in addition to the combination of the motor drive device and the motor. Furthermore, if a network that integrates host systems and a serial communication system with transparency can be used, the scope of application of this system can be expanded to remote operation and remote diagnosis through integration with systems beyond motor control. Have the potential to realize.

1 is a block diagram of a motor drive system according to a first embodiment of the present invention. Time chart of motor drive system in Embodiment 2 of the present invention Time chart of motor drive system in Embodiment 3 of the present invention Time chart of motor drive system in Embodiment 4 of the present invention Time chart of motor drive system in Embodiment 5 of the present invention Block diagram of motor drive system in Embodiment 6 of the present invention The time chart of the motor drive system in Example 6 of this invention Block diagram of motor drive system in Embodiment 7 of the present invention The time chart of the motor drive system in Example 7 of this invention

Explanation of symbols

1, 1a, 1b Host system 11, 11a, 11b Command generation unit 12, 12a, 12b Serial communication unit 13, 13a, 13b Command generation processing 14, 14a, 14b Command information 15 Status generation processing 16 Status information 2, 2a, 2b Motor drive unit 21, 21a, 21b Motor control unit 22, 22a, 22b Serial communication unit 23, 23a, 23b Motor control process 25 Status generation process 26 Status information 3, 3a, 3b Encoder 31, 31a, 31b Motor state detection unit 32 , 32a, 32b Serial communication unit 33, 33a, 33b Motor state detection process 34, 34a, 34b Motor information 35 Status generation process 36 Status information 37a, 37b Motor information output determination process 4, 4a, 4b Motor 5 Communication path

Claims (7)

A host system including a command generation unit and a serial communication unit, a motor driving device including a motor control unit and a serial communication unit, a serial encoder including a motor state detection unit and a serial communication unit, and a motor, A motor drive system characterized in that serial communication units of a host system, a motor drive device, and a serial encoder are connected to the same communication path. The motor drive device starts the operation of the motor control unit in synchronization with the command information transmitted from the host system, and the serial encoder latches the motor information of the motor state detection unit in synchronization with the command information, 2. The motor drive system according to claim 1, wherein transmission of information is started. The motor drive system according to claim 2, wherein the motor drive device transmits the status information of the motor drive device after receiving the motor information of the serial encoder. The motor drive system according to claim 2, wherein the serial encoder transmits status information of the serial encoder after completion of transmission of the motor information of the serial encoder. 3. The motor drive system according to claim 2, wherein the host system transmits status information of the host system after completion of motor information reception of the serial encoder. 3. The motor drive system according to claim 2, wherein one upper system, a plurality of sets of motor drive devices, and a serial encoder are connected to the same communication path. 3. The motor drive system according to claim 2, wherein a plurality of host systems, one set or a plurality of sets of motor drive devices, and a serial encoder are connected to the same communication path.