JP6464052B2 - Distributed control device - Google Patents

Description

  The present invention relates to a control system used for industrial machines and the like, and more particularly to a redundancy technique for a control function in a distributed control apparatus that controls the whole by a plurality of units.

  Control devices used in recent industrial machines are divided into a plurality of control units according to the control device target, in order to reduce the amount of wiring between the devices and the control device, and to reduce the device size of the control device. It may take the form of a distributed control device that is connected by communication and controls the whole. Taking an elevator, an industrial machine, as an example, an operation control unit that controls the operation of a car, a motor control unit that controls a hoisting motor, a car control unit that controls a car, and a door control unit that controls the opening and closing of a door. For example, it is divided into a hall operation panel control unit that controls the operation panel of the hall, and a group management control unit that optimally allocates a plurality of cars according to a call from a user.

  However, in such a distributed control device, when a failure occurs in any of the control units, a series of control cannot be continued. For example, in the case of an elevator control device, the operation of the elevator is performed by a safety device. Had to be stopped.

  As means for solving such a problem, for example, as described in Patent Document 1, a plurality of processors that perform control are prepared, the same control processing is performed, and a signal indicating normality is output. A redundancy method for selecting and operating the control output which is normally operating is provided.

JP-A-4-41960

  Here, when controlling a whole by connecting a plurality of control units by network communication like a distributed control device, even if one control unit fails by connecting a plurality of the same control units on the network, Control can be continued using a control command output by another identical control unit. At this time, when a plurality of the same control units are not operating in synchronization, the plurality of the same control units may generate different control commands within the range of one control cycle. In this case, a method of waiting for one cycle until a plurality of control commands become the same and adopting it as a correct control command is required, and a delay in units of cycles occurs.

  As a method of operating a plurality of identical control units in synchronism, for example, a method of operating one control unit on the network as a master unit and synchronizing the whole in accordance with an instruction from the master unit is employed. However, when any one of the control units is a master unit, there is a problem that the control cannot be continued because the master unit cannot be synchronized when it fails.

  In order to solve the above-described problem, a distributed control apparatus is provided that includes a plurality of control units and a plurality of communication paths that connect the plurality of control units, and each of the plurality of control units synchronizes the control units. Synchronization means for synchronizing, and a synchronization means for synchronizing with a cycle counter that counts a cycle count value that is a control cycle and resets the cycle count value to 0 when the cycle count value is counted up to a predetermined value The means includes a synchronization packet transmission unit that transmits a synchronization packet including relay count information, a synchronization packet reception unit that receives a synchronization packet transmitted from another control unit, and that the synchronization packet has been transmitted or other A synchronization packet transmission / reception flag storage unit for storing synchronization packet transmission / reception status information indicating that the received from the control unit, The initialization packet is configured to have the first relay count of communication between control units, and is a value obtained by multiplying the relay count included in the received synchronization packet by 1 and a preset basic delay value. A synchronization timing value calculation unit that generates a certain synchronization timing value, and whether the synchronization packet transmission / reception status information indicates that the synchronization packet transmission / reception status is not received, or the synchronization timing value is greater than the cycle count value If the value is large, a synchronization timing value is set as a cycle count value, and a synchronization packet having a relay count that is a value obtained by adding 1 to the relay count included in the received synchronization packet is transmitted via the synchronization packet transmitter. The synchronization packet transmission / reception status information stored in the synchronization packet transmission / reception flag storage unit There comprises a synchronization timing comparator setting section for updating the status being received, to provide a distributed control system, characterized in that.

  In order to continue control even when some control units fail, there is no master unit for synchronizing means to operate multiple control units synchronously when the same control unit is connected to multiple networks. Can be built.

It is a figure which shows the basic composition of the elevator control apparatus concerning embodiment of this invention. It is the figure which showed the structural example of the synchronization means concerning embodiment of this invention. It is the figure which showed the flowchart of the synchronization means concerning embodiment of this invention. It is the figure which showed the timing chart of the synchronization means concerning embodiment of this invention.

Hereinafter, an embodiment will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a basic configuration of an elevator control apparatus according to this embodiment. The distributed control device is not limited to an elevator control device, and is generally effective for a device that requires a function to continue control even when some control devices fail. For example, railways, automobiles, construction equipment, etc.

  In this embodiment, as control units in the elevator control device, operation control units 101a, 101b, 101c, 101d for controlling the operation of the cars of different cars and group management control units 102a, 102b for controlling the operation control units are provided. Prepare. The group management control units 102a and 102b perform the same control process, and even if one of them fails, the other one operates to continue the entire control process. In addition, the motor control unit and the car control unit are actually provided in addition to this, but the illustration is omitted here. Each control unit includes a network control unit 300 that performs communication with other control units, and a processor 400 that performs control processing shown in FIG.

  The group management control unit 102a is connected to the operation control unit 101a via the communication path 200a, the operation control unit 101a is connected to the operation control unit 101b via the communication path 200b, and the operation control unit 101b is connected to the operation control unit 101c via the communication path 200c. The operation control unit 101c is connected to the operation control unit 101d via the communication path 200d, and the operation control unit 101d is connected to the group management control unit 102b via the communication path 200e. The connection of each control unit is not limited to the connection form of this example, and all the control units need only be connected via a communication path. The communication paths 200a to 200e may be so-called full-duplex connection or half-duplex connection as long as the connected control units can transmit and receive. Further, FIG. 1 shows only two group management control units and four operation control units, but this number is not limited to this. Each control unit constituting these elevator control devices is mounted on or connected to the elevator body. A combination of the elevator control device and the elevator body is referred to as an elevator system.

  Next, the movement of the control command output by each control unit will be described with reference to FIG. The group management control unit 102a performs control calculation based on the control command output from the operation control units 101a to 101d, and outputs the control command to the operation control units 101a to 101d. The control commands output by the operation control units 101a to 101d are, for example, the current position of the car controlled by each operation control unit, the car call floor designated by the elevator user using a call button, etc., and the group management control unit 102a Is a car number indicating a car to be dispatched to the car call floor designated by the user. The control command output by the group management control unit 102a is transmitted to each control unit via the communication paths 200a to 200e. The group management control unit 102b operates in the same manner as the group management control unit 102a.

  Here, if each control unit has already received the same control command within the same control cycle, the newly received control command is discarded. For example, when the operation control unit 101a has received the control command transmitted from the group management control unit 102a and has received the same control command of the same control period from the group management control unit 102b, the control command is Discard. At this time, it is only necessary to know that they are the same control cycle and the same control command, and it is not necessary to determine which control unit of the group management control units 102a and 102b is the control command.

  Here, when the group management control unit 102a fails, the group management control unit 102a does not output a control command, but each control unit receives the control command output by the group management control unit 102b and continues control. . Since each control unit is operating without determining which group management control unit is outputting the control command from the normal state, one of the group management control units will issue the control command due to a failure. Control can be continued without any trouble even if output is stopped.

  In order to realize such an operation, it is necessary for a plurality of group management control units to output the same control command within the same control cycle. This requires synchronization in which control processing is performed at the same timing within the same control cycle.

  Details of the synchronization means 301 included in the network control unit 300 will be described with reference to FIG. The network control unit 300 includes synchronization means 301, a plurality of communication ports 302, and a communication control unit 303. FIG. 2 shows an example in which two communication ports 302 are provided. The communication port 302 performs transmission / reception processing of communication packets with other control units. The communication control unit 303 outputs a communication packet received from another control unit to the synchronization unit 301 or the processor 400 according to the type, and transmits the communication packet output from the synchronization unit 301 or the processor 400 to the other control unit. To do. Further, when the communication control unit 303 has already received the same control command with the same cycle, the communication control unit 303 performs processing for discarding the newly received communication packet.

  The synchronization unit 301 includes a period counter 500, a synchronization timing comparison setting unit 501, a synchronization timing value calculation unit 502, a synchronization packet reception unit 503, a synchronization packet transmission unit 504, and a synchronization packet transmission / reception flag storage unit 505. . In this embodiment, the synchronization packet includes at least flag information indicating that it is a synchronization packet and relay count information TD. The cycle counter 500 counts up the cycle count value TC at a constant interval, and resets the cycle count value TC and outputs a count trigger again when a cycle trigger is output to the processor 400 when reaching a preset value. repeat. The synchronization packet receiving unit 503 receives the synchronization packet transmitted from another control unit from the communication control unit 303, and calculates the synchronization timing value with the number of relays stored in the synchronization packet as the first relay number TD1. Output to the unit 502. The synchronization timing value calculation unit 502 adds 1 to the first relay count TD1 and multiplies the basic delay value BD indicating the communication delay time of the network set in advance to obtain the synchronization timing value TP. Output to the comparison setting unit 501. The synchronization packet transmission / reception flag storage unit 505 manages the synchronization packet transmission / reception flag TS by the synchronization timing comparison / setting unit by the synchronization timing comparison / setting unit 501 and sets 1 when the synchronization packet is received or transmitted. Otherwise, 0 is stored. The synchronization timing comparison setting unit 501 receives the synchronization timing value TP, and if the synchronization packet transmission / reception flag TS is 0, or if the synchronization timing value TP is larger than the cycle count value TC, the cycle count value TC Is replaced with the synchronization timing value TP, the synchronization packet transmission / reception flag TS is set to 1, and a value obtained by adding 1 to the first relay count TD1 is output to the synchronization packet generator as the second relay count TD2. . Here, the second relay count TD2 simply refers to the relay count TD as a relationship between TD1 and TD2 for the sake of convenience in order to clarify TD1 as an input to the control unit and TD2 as an output. TD1 and TD2 are the same quality as the number of relays, and the control unit that receives TD2 operates as if it received TD1. If the synchronization packet transmission / reception flag TS is 1 and the synchronization timing value TP is small, nothing is done. Here, the size of the comparison only needs to be unified as a whole, and the determination may be reversed. The synchronization timing comparison setting unit 501 sets the synchronization packet transmission / reception flag TS to 1 when the cycle count value TC reaches a preset value (for example, when it is reset to 0 after counting for one cycle). At the same time, the second relay count TD2 is set to 0 and output to the synchronized packet transmission 504. When the cycle counter TC reaches a preset value (for example, half the value for one cycle), the synchronization packet transmission / reception flag TS is set in order to determine that the synchronization of one cycle has been completed and reset it. Set to 0. The synchronization packet transmission unit 504 generates a synchronization packet with a flag indicating that it is a synchronization packet added to the second relay count TD2 output by the synchronization timing comparison setting unit 501, and outputs it to the communication control unit 303. .

Next, the synchronization procedure will be described with reference to the flowchart of FIG. When the control unit is activated at each timing, the synchronization packet transmission / reception flag TS and the synchronization count value TC are set to 0 (procedure 601), and then the cycle count value TC is counted up (procedure 602). If a synchronization packet is received from another control unit while the period count value TC is being counted up, the procedure proceeds to step 609, and if not, the count is continued (step 603). When the cycle counter value TC reaches a preset value C1 (for example, a half count value for one cycle) (procedure 604), it is determined that the synchronization of the cycle is completed, and the synchronization of the next cycle is performed. In order to prepare, the synchronization packet transmission / reception flag TS is set to 0 (procedure 608), and the process returns to procedure 602. When the cycle counter value TC reaches a preset value C2 (for example, a count value for one cycle), it is determined that the count for one cycle has ended (step 605), and the cycle count value TC is reset (step 605). Procedure 606) Note that C1 <C2. Thereafter, the synchronization packet with the second relay count TD2 set to 0 is transmitted to the other control unit, and the synchronization packet synchronization packet synchronization packet synchronization packet transmission / reception flag TS is set to 1 (procedure 607). When the synchronization packet is received in step 603, 1 is added to the first relay count TD1 included in the synchronization packet and multiplied by the basic delay value BD to obtain the synchronization timing value TP (step 609). .
When the synchronization packet transmission / reception flag TS is 0 or when the synchronization timing value TP is larger than the cycle count value TC (procedure 610), the cycle count value TC is replaced with the synchronization timing value TP and the second relay A synchronization packet in which the number of times TD2 is set to the synchronization timing value TP is transmitted to another control unit (procedure 611). In this procedure, an example is shown in which synchronization is performed every cycle. However, synchronization may be performed once in a plurality of preset state areas.

  Next, an example in which synchronization is performed using the synchronization means of the present embodiment in the connection configuration of FIG. 1 will be described using the timing chart of FIG. Since the operation is the same in all the control units, FIG. 4 describes and describes only the group management control unit 102a and the operation control units 101a to 101d illustrated in FIG. In this example, it is assumed that one cycle is 99 and the basic delay value BD is 8.

  At the timing of T = 0 in FIG. 4, the cycle counter TC of each control unit shows a different value. This is performed by the following procedure to match the values of the cycle counters TC of the control units, that is, synchronization.

  At T = 0, the synchronization packet transmission / reception flag TS indicates 0 in any control unit, indicating that no synchronization packet is transmitted / received. At T = 1, the group management control unit 102a indicates a value of TC = 0, so that the synchronization packet with the second relay count TD2 set to 0 is sent to another connected control unit, that is, the operation control unit 101a. At the same time as transmitting, the synchronization packet transmission / reception flag TS is set to 1.

  At T = 4, since the cycle counter TC of the operation control unit 101c is 0, a synchronization packet with the second relay count TD2 set to 0 is transmitted to the operation control unit 101b and the synchronization packet transmission / reception flag TS is set to 1. Set.

  At T = 7, since the cycle counter TC of the operation control unit 101b is 0, a synchronization packet with the second relay count TD2 set to 0 is transmitted to the operation control units 101a and 101c and a synchronization packet transmission / reception flag TS is set. Set to 1.

  At T = 9, the operation control unit 101a receives the synchronization packet transmitted by the group management control unit 102a. The reception at T = 9 is because the basic delay value considering the communication delay by the network is set to 8 in this example, and this value is determined according to the actual communication delay. The operation control unit 101a multiplies the basic delay value BD (= 8) by the value (= 1) obtained by adding 1 to the first relay count TD1 (= 0) stored in the received synchronization packet, and the synchronization timing The value TP is set to 8. Here, since the synchronization packet transmission / reception flag TS is 0, the cycle count value TC is replaced with the synchronization timing value TP, and a synchronization packet with the second relay count TD2 set to 1 is transmitted to the operation control unit 101b. At the same time, the synchronization packet transmission / reception flag TS is set to 1.

  At T = 12, the operation control unit 101b receives the synchronization packet transmitted by the operation control unit 101c. The operation control unit 101b multiplies the basic delay value BD (= 8) by the value (= 1) obtained by adding 1 to the first relay count TD1 (= 0) stored in the received synchronization packet, and the synchronization timing The value TP is set to 8. Here, since the synchronization packet transmission / reception flag TS is 1, the cycle count value TC is compared with the synchronization timing value TP. In this example, TC is 5 and the synchronization timing value TP is more likely to be 8. Therefore, TC is replaced with 8 which is the value of TP, and the second relay count TD2 is set to 8 for the operation control unit 101a. Send a synchronization packet.

  At T = 15, the operation control unit 101a receives the synchronization packet transmitted by the operation control unit 101b. The operation control unit 101a multiplies the basic delay value BD (= 8) by the value (= 1) obtained by adding 1 to the first relay count TD1 (= 0) stored in the received synchronization packet, and the synchronization timing The value TP is set to 8. Since the synchronization packet transmission / reception flag TS is 1, the cycle count value TC (= 14) is compared with the synchronization timing value TP (= 8), and the synchronization timing value TP is smaller. Delete the synchronization packet. In parallel, the operation control unit 101c receives the synchronization packet transmitted by the operation control unit 101b, and similarly deletes the synchronization packet without transferring it.

  At T = 17, the operation control unit 101b receives the synchronization packet transmitted by the operation control unit 101a. The operation control unit 101b multiplies the value (= 2) obtained by adding 1 to the first relay count TD1 (= 1) stored in the received synchronization packet by the basic delay value BD (= 8), and the synchronization timing. The value TP is set to 16. Since the synchronization packet transmission / reception flag TS is 1, the cycle count value TC (= 13) is compared with the synchronization timing value TP (= 16). A synchronization packet with the second relay count TD2 set to 2 is transmitted to 101c.

  At T = 20, the operation control unit 101a receives the synchronization packet transmitted by the operation control unit 101b. The operation control unit 101a multiplies the basic delay value BD (= 8) by the value (= 2) obtained by adding 1 to the first relay count TD1 (= 1) stored in the received synchronization packet, and the synchronization timing The value TP is set to 16. Since the synchronization packet transmission / reception flag TS is 1, the cycle count value TC (= 19) is compared with the synchronization timing value TP (= 16), and nothing is performed because the synchronization timing value TP is smaller. Delete the synchronization packet without forwarding it.

  At T = 25, the operation control unit 101c receives the synchronization packet transmitted by the operation control unit 101b. The operation control unit 101c multiplies the basic delay value BD (= 8) by the value (= 3) obtained by adding 1 to the first relay count TD1 (= 2) stored in the received synchronization packet, and the synchronization timing The value TP is 24. Since the synchronization packet transmission / reception flag TS is 1, the cycle count value TC (= 21) is compared with the synchronization timing value TP (= 24). Since the synchronization timing value TP is larger, the synchronization packet transmission / reception flag TS is replaced. A synchronization packet with the second relay count TD2 set to 3 is transmitted to the operation control unit. At the time T = 25, the cycle counters TC of the four control units shown in FIG. The basic delay value sets a delay value when communication is performed between two control units. That is, the time for executing processing related to communication in the communication port 302 and the communication control unit 303 is combined with the time for executing processing related to synchronization by the synchronization unit 301. In addition, when the communication control unit 303 performs a process of selecting one of the synchronization packets when a plurality of synchronization packets are received at the same time, the communication control unit 303 selects the synchronization packet that has not been selected. A process of adding a delay for waiting for only the synchronization packet that has not been performed to the synchronization timing value TP may be performed.

  In the embodiment, the example in which the number of relays is stored in the synchronization packet has been described. However, this may store the actual delay value calculated by multiplying the relay number by the basic delay value BD or the like. In this case, the synchronization timing value calculation unit 502 uses a value obtained by adding the actual delay value and the basic delay value BD as the synchronization timing value. When the synchronization packet is transferred to another control unit, the synchronization timing value is transmitted as an actual delay value.

101 operation control unit 102 group management unit 200 communication path 300 network control unit 301 synchronization means 302 communication port 303 communication control unit 400 processor

Claims (6)

A plurality of control units and a plurality of communication paths connecting the plurality of control units;
A decentralized control device,
Each of the plurality of control units includes synchronization means for synchronizing the control units,
The synchronization means includes
A cycle counter that counts a cycle count value that is a control cycle and resets the cycle count value to 0 when the cycle count value is counted up to a predetermined value;
The synchronization means transmits a synchronization packet including relay number information, and a synchronization packet transmitter;
A synchronization packet receiver for receiving the synchronization packet transmitted from another control unit;
A synchronization packet transmission / reception flag storage unit for storing synchronization packet transmission / reception status information indicating that the synchronization packet has been transmitted or received from another control unit;
A synchronization timing value calculation unit that generates a synchronization timing value that is a value obtained by multiplying a number obtained by adding 1 to the number of times of relay included in the received synchronization packet and a preset basic delay value;
When the synchronization packet transmission / reception status information indicates that the synchronization packet transmission / reception status is not received, or when the synchronization timing value is larger than the cycle count value, the synchronization is performed as the cycle count value. A timing value is set, and the synchronization packet having a value obtained by adding 1 to the number of relays included in the received synchronization packet is set as the number of relays is transmitted to another control unit via the synchronization packet transmission unit. A synchronization timing comparison setting unit that updates the synchronization packet transmission / reception status information stored in the synchronization packet transmission / reception flag storage unit to a status where the synchronization packet transmission / reception status is received,
A distributed control device. The distributed control device according to claim 1,
The synchronization timing comparison setting unit is configured to receive the synchronization packet transmission / reception status information stored in the synchronization packet transmission / reception flag storage when the synchronization packet is received from another control unit among the plurality of control units. When the synchronization packet transmission / reception status is received and the period count value is equal to or greater than the synchronization timing value, the received synchronization packet is deleted without being transferred to another control.
A distributed control device. The distributed control device according to claim 2,
The distributed control device, wherein the basic delay value is set according to a communication delay when network communication is performed between two control devices. The distributed control device according to claim 2,
The distributed control device, wherein the synchronization packet includes information indicating that it is a synchronization packet. The distributed control device according to claim 2,
Each of the plurality of control units includes a communication control unit,
The communication control unit, when receiving a plurality of the synchronization packets at the same time, discards any one of the synchronization packets or selects any one of the synchronization packets and outputs the selected synchronization packet to the synchronization unit, Hold unsynchronized packets until the selected sync packet is processed,
The distributed control apparatus, wherein the synchronization timing value calculation unit adds a time held by the communication control unit to a time when the unselected synchronization packet calculates the synchronization timing value. A plurality of control units and a plurality of communication paths connecting the plurality of control units;
A decentralized control device,
Each of the plurality of control units includes synchronization means for synchronizing the control units,
The synchronization means includes
A cycle counter that counts a cycle count value that is a control cycle and resets the cycle count value to 0 when the cycle count value is counted up to a predetermined value;
The synchronization means transmits a synchronization packet including a real delay value that is a communication delay time caused by relaying between control units;
A synchronization packet receiver for receiving the synchronization packet transmitted from another control unit;
A synchronization packet transmission / reception flag storage unit for storing synchronization packet transmission / reception status information indicating that the synchronization packet has been transmitted or received from another control unit;
A synchronization timing value calculation unit that generates a synchronization timing value that is a value obtained by adding a basic delay value to the actual delay value;
When the synchronization packet transmission / reception status information indicates that the synchronization packet transmission / reception status is not received, or when the synchronization timing value is larger than the cycle count value, the synchronization is performed as the cycle count value. A timing value is set, and the synchronization packet having the synchronization timing value as the actual delay value is transmitted to another control unit via the synchronization packet transmission unit, and stored in the synchronization packet transmission / reception flag storage unit. The synchronization packet transmission / reception status information is updated to a status where the synchronization packet transmission / reception status is received.
A distributed control device.

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