control system

Abstract

To provide a control system capable of easily detecting a configuration that does not meet a predetermined configuration condition.SOLUTION: A control system comprises: a plurality of control units that supply drive current to corresponding electric motors; and a management unit connected to the plurality of control units. The management unit is configured to: acquire, at the time of starting up, a combination of upper limits of the drive current that the respective connected control units can supply and capacities of the electric motors associated with the respective control units; determine whether or not the combination meets a configuration condition related to the combination of upper limits of the drive current and capacities of the electric motors that is previously stored in a storage section; and output an alarm when the combination does not meet the configuration condition.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a control system.

Background Art

[0002] In a system to which a plurality of units are connected, a technique for detecting a configuration change based on the acquired connection order of the units and the stored connection order of the units has been proposed (see, for example, Patent Documents 1-3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a control system for controlling a motor, generally, motor control is performed by a driver according to a command from a controller such as a PLC, or motor control is performed based on preset information. In such a control system, a control system for driving a plurality of axes is also used.

[0005] In recent years, a so-called building block type control system in which a plurality of inverter units for controlling a motor are connected to a converter unit that outputs AC power to DC power has also been used. And, it has been confirmed based on design drawings etc. whether the control system has a correct configuration (for example, a configuration that can operate the motor normally), which has become a burden on the operator and there is also a risk of overlooking and judging an incorrect configuration as a correct configuration.

[0006] One aspect of the disclosed technology aims to provide a control system that can easily detect configurations that do not meet predetermined configuration conditions. [Means for solving the problem]

[0007] One aspect of the disclosed technology is illustrated by the following control system: The control system comprises a plurality of control units that supply drive current to corresponding motors, and a management unit connected to the plurality of control units. The management unit acquires, at startup, the upper limit of the drive current that each of the connected plurality of control units can supply and the capacity of the motor associated with each of the plurality of control units, determines whether the combination satisfies the configuration conditions related to the combination of the upper limit of the drive current and the capacity of the motor stored in a memory unit in advance, and outputs an alarm if the combination does not satisfy the configuration conditions.

[0008] According to the control system described above, the combination of the upper limit of the drive current that the control unit can supply and the capacity of the motor that receives the drive current from the control unit is acquired when the control system is started. If the acquired combination does not meet the configuration conditions stored in the memory unit in advance, an alarm is output. Therefore, with this control system, configurations that do not meet the predetermined configuration conditions can be easily detected without having to check design drawings or the like. One of the multiple control units may also serve as the management unit. In other words, the management unit may supply the drive current to the motor.

[0009] The above control system may have the following features: The management unit prohibits the supply of the drive current by the multiple control units if the above combination does not satisfy the above configuration conditions. By having such features, this control system can prohibit the supply of drive current in cases where a dangerous power supply may occur.

[0010] The above control system may have the following features: The management unit outputs an alarm or prohibits the supply of drive current by the multiple control units if the combination acquired at the time of the current startup is different from the combination acquired at the time of the previous startup. By having such features, this control system can detect configuration changes from a configuration that has already been proven to be safe to operate, and can also deter easy configuration changes.

[0011] The above control system may have the following features: The management unit may suppress the output of the alarm or permit the supply of the drive current by the multiple control units, even if the combination acquired at the current startup is different from the combination acquired at the previous startup, as long as the combination acquired at the current startup satisfies the above configuration conditions. By having such features, the control system can be flexibly modified as long as the configuration conditions are met. [Effects of the Invention]

[0012] According to the disclosed technology, configurations that do not meet the specified configuration conditions can be easily detected. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 shows an example of a servo system according to an embodiment. [Figure 2] Figure 2 is a schematic diagram showing the connection between the converter unit and the inverter unit in the servo system according to the embodiment. [Figure 3] Figure 3 illustrates a configuration in which a converter unit and an inverter unit are connected via an internal bus in a servo system according to an embodiment. [Figure 4] Figure 4 is a diagram illustrating the schematic configuration of the functional components of the control circuit. [Figure 5] Figure 5 shows an example of a configuration management table that stores the combinations acquired by the acquisition unit. [Figure 6] Figure 6 shows an example of configuration conditions stored in the memory unit in this embodiment. [Figure 7] Figure 7 shows an example of the processing flow of the servo system according to the embodiment. [Modes for carrying out the invention]

[0014] <Embodiment> The servo system according to the embodiment will be described below with reference to the drawings. Figure 1 is a diagram showing an example of the servo system 100 according to the embodiment. The servo system 100 includes a converter unit 1, an inverter unit 2a, an inverter unit 2b, and an inverter unit 2c. A servo motor 3a is connected to inverter unit 2a, a servo motor 3b is connected to inverter unit 2b, and a servo motor 3c is connected to inverter unit 2c. When inverter units 2a, 2b, and 2c are not distinguished, they will also be referred to as inverter unit 2. Similarly, when servo motors 3a, 3b, and 3c are not distinguished, they will also be referred to as servo motor 3. A PLC 5 is connected to the servo system 100 via an industrial network N1.

[0015] PLC5 outputs command signals to the converter unit 1 and inverter unit 2 of the servo system 100 via the industrial network N1. PLC5 functions, for example, as a monitoring device for the servo system 100 by executing processes according to a pre-prepared program. The industrial network N1 is, for example, a TCP / IP network.

[0016] The servo system 100 is a building block type servo system including a converter unit 1 and a plurality of inverter units 2. In the servo system 100, a plurality of inverter units 2 can be connected to one converter unit 1, and the inverter units 2 connected to the converter unit 1 can be disconnected from the converter unit 1. In FIG. 1, the servo system 100 includes three inverter units 2, but the number of inverter units 2 may be two or less or four or more. The servo system 100 is an example of a "control system".

[0017] The converter unit 1 and the inverter units 2 receive command signals from the PLC 5 via the industrial network N1. The converter unit 1 distributes the command signals received from the PLC 5 and the current received from a power supply (not shown) to the inverter units 2. The converter unit 1 is an example of a "management unit".

[0018] The inverter units 2 receive a current supply from the converter unit 1 and supply a drive current to the servo motor 3. The inverter units 2 receive a feedback signal from the servo motor 3. In each of the inverter units 2, a servo system that performs feedback control using a position controller, a speed controller, a current controller, etc. is formed, and the servo motor 3 is servo-controlled and driven using these signals. The inverter units 2 are an example of a "control unit".

[0019] The servo motor 3 is, for example, an AC servo motor. The servo motor 3 operates by receiving the drive current supplied from the inverter unit 2. The servo motor 3 detects the displacement of the output shaft of the servo motor 3 and outputs a feedback signal indicating the detected displacement to the inverter unit 2. The servo motor 3 is an example of an "electric motor".

[0020] Figure 2 is a schematic diagram showing the connection between the converter unit 1 and the inverter unit 2 in the servo system 100 according to the embodiment. A female other-unit connection port 113 is provided on the side of the converter unit 1. A male upstream connection terminal 221 is provided on the side of the inverter unit 2 that is on the converter unit 1 side (upstream side). A female downstream connection port 222 is provided on the side of the inverter unit 2 that is on the opposite side from the converter unit 1 side (downstream side). The other-unit connection port 113 of the converter unit 1 is connected to the upstream connection terminal 221 of the inverter unit 2a, the downstream connection port 222 of the inverter unit 2a is connected to the upstream connection terminal 221 of the inverter unit 2b, and the downstream connection port 222 of the inverter unit 2b is connected to the upstream connection terminal 221 of the inverter unit 2c.

[0021] Figure 3 illustrates a configuration in the servo system 100 according to the embodiment, where the converter unit 1 and the inverter unit 2 are connected via an internal bus B1. In the converter unit 1, a control circuit 101 that controls the supply of current to the inverter unit 2 and the exchange of information with the inverter unit 2 is connected to the internal bus B1. In the inverter unit 2a, a control circuit 201a that controls the servo motor 3a is connected to the internal bus B1. In the inverter unit 2b, a control circuit 201b that controls the servo motor 3b is connected to the internal bus B1. In the inverter unit 2c, a control circuit 201c that controls the servo motor 3c is connected to the internal bus B1. (Control circuits 201a, 201b, 201) If c is not distinguished, it is also called control circuit 201.

[0022] In the servo system 100, the converter unit 1 and the inverter unit 2 are connected as illustrated in Figure 2, thereby connecting the internal bus B1 of the converter unit 1 and the inverter unit 2. With the internal bus B1 connected, the control circuit 101 can supply current to the control circuit 201 and exchange information with the control circuit 201.

[0023] The control circuit 201 can be considered as a computer having an arithmetic unit, memory, etc. In the control circuit 201, various information such as the ID assigned to its unit, the power and voltage that can be supplied to the servo motor 3, and the capacity of the servo motor 3 is stored in the memory. The control circuit 201 then provides the information stored in the memory to the converter unit 1 in response to a request from the converter unit 1. Here, each of the inverter units 2a, 2b, and 2c is assigned a unique ID. There are no limitations on the method of assigning a unique ID to each of the inverter units 2a, 2b, and 2c. For example, each of the inverter units 2a, 2b, and 2c may have a unique ID stored in the memory at the time of factory shipment. Alternatively, each of the inverter units 2a, 2b, and 2c may be assigned a unique ID generated by the converter unit 1 based on, for example, the serial number and model of the inverter unit 2.

[0024] Figure 4 is a diagram illustrating the schematic configuration of the functional units of the control circuit 101. The control circuit 101 can be considered as a computer having an arithmetic unit, memory device, etc. The functional units shown in Figure 4 are realized by the execution of a predetermined program, etc., in the control circuit 101. The control circuit 101 has an acquisition unit 11, a determination unit 12, an output unit 13, a prohibition unit 14, and a storage unit 15, but it may also have other functional units.

[0025] The acquisition unit 11 accesses the control circuit 201 of the inverter unit 2 via the internal bus B1 and acquires the combination of the ID and capacity of the inverter unit 2 and the capacity of the servo motor 3 connected to the inverter unit 2 when the servo system 100 is started. Specifically, the acquisition unit 11 accesses the control circuit 201 of the inverter unit 2a and acquires the combination of the ID, capacity and input voltage of the inverter unit 2a and the capacity of the servo motor 3a connected to the inverter unit 2a. The acquisition unit 11 also accesses the control circuit 201 of the inverter unit 2b and acquires the combination of the ID and capacity of the inverter unit 2b and the capacity of the servo motor 3b connected to the inverter unit 2b. Furthermore, the acquisition unit 11 accesses the control circuit 201 of the inverter unit 2c and acquires the combination of the ID and capacity of the inverter unit 2c and the capacity of the servo motor 3c connected to the inverter unit 2c. The acquisition unit 11 may also acquire the connection order of the inverter units 2 from upstream to downstream as a combination. The acquisition unit 11 stores the acquired combinations in the storage unit 15.

[0026] Figure 5 shows an example of a configuration management table 151 that stores combinations acquired by the acquisition unit 11. The configuration management table 151 includes the following items: "Connection Order", "ID", "Inverter Capacity", "Voltage", and "Motor Capacity". "Connection Order" stores the connection order of the inverter units 2. For example, the connection order of the inverter unit 2 connected to the uppermost position is set to "1", and the numerical value indicating the connection order increases by 1 towards the downstream. "ID" stores the unique ID assigned to the inverter unit 2. "Inverter Capacity" stores the capacity of each inverter unit 2. "Voltage" stores the voltage input to the inverter unit 2. "Motor Capacity" stores the capacity of the servo motor 3 connected to the inverter unit 2 identified by "ID".

[0027] In the servo system 100 illustrated in Figure 1, for example, the connection of the inverter unit 2a The order is "1", the connection order of inverter unit 2b is "2", and the connection order of inverter unit 2c is "3". If the combination acquired by the acquisition unit 11 is the configuration management table 151 exemplified in Figure 5, then it can be understood that the ID of inverter unit 2b is "B", the capacity of inverter unit 2b is "400W", the input voltage of inverter unit 2b is "100V", and the capacity of servo motor 3b connected to inverter unit 2b is "400W".

[0028] The determination unit 12 determines whether the combination acquired by the acquisition unit 11 satisfies the configuration conditions pre-stored in the storage unit 15. Figure 6 shows an example of configuration conditions 152 stored in the storage unit 15 in an embodiment. The configuration conditions 152 illustrated in Figure 6 include the items "number" and "condition". The "number" stores a unique number that uniquely identifies the condition. The "condition" stores the conditions imposed on the inverter unit 2 and the servo motor 3 in order for the servo system 100 to operate normally. In Figure 6, three configuration conditions are listed, but there may be two or fewer configuration conditions, or four or more. The configuration conditions 152 are stored in the storage unit 15, for example, at the time of factory shipment.

[0029] Furthermore, configuration condition 152 may include conditions other than those listed in Figure 6, such as "the capacity of the inverter unit 2 connected to the upstream side is equal to or greater than the capacity of the inverter unit 2 connected to the downstream side," "the capacity of the servo motor 3 is equal to or less than the capacity of the connected inverter unit 2," "the total capacity of the inverter units 2 connected to the servo system 100 is 800W or less," and "the input voltage of the inverter unit 2 is 100V." Also, configuration condition 152 may be modified or deleted from some of the conditions listed in Figure 6.

[0030] The determination unit 12 makes a negative determination if the combination acquired by the acquisition unit 11 does not satisfy the configuration condition 152. The determination unit 12 may also make a negative determination if the combination acquired by the acquisition unit 11 at the time of this startup is different from the combination acquired by the acquisition unit 11 at the time of the previous startup and stored in the storage unit 15.

[0031] The output unit 13 outputs an alarm if the determination unit 12 determines that the result is negative. The alarm output may be, for example, an alarm sound, an error message, or an email.

[0032] The prohibition unit 14 prohibits the supply of drive current from the inverter unit 2 to the servo motor 3 when the determination unit 12 makes a negative determination. The prohibition unit 14 may, for example, prohibit the supply of drive current from the inverter unit 2 to the servo motor 3 by stopping the supply of current from the converter unit 1 to the inverter unit 2.

[0033] Here, even if the combination acquired by the acquisition unit 11 during the current startup is different from the combination acquired by the acquisition unit 11 during the previous startup and stored in the storage unit 15, the prohibition unit 14 does not need to prohibit the supply of drive current from the inverter unit 2 to the servo motor 3 if the combination acquired by the acquisition unit 11 during the current startup satisfies the configuration conditions 152 that have been previously stored in the storage unit 15.

[0034] <Processing flow of servo system 100> Figure 7 shows an example of the processing flow of the servo system 100 according to the embodiment. Hereinafter, an example of the processing flow of the servo system 100 will be described with reference to Figure 7. In the example shown in Figure 7, the configuration condition 152 exemplified in Figure 6 is assumed to be adopted as the configuration condition.

[0035] In S1, the servo system 100 is started. In S2, the acquisition unit 11 switches to the inverter. The combination of unit 2 and servo motor 3 is acquired. The acquisition unit 11 stores the acquired combination in the configuration management table 151.

[0036] In S3, it is determined whether the combination acquired by the acquisition unit 11 during the previous startup is already stored in the storage unit 15. If it is already stored (YES in S3), the process proceeds to S5. If it is not already stored (NO in S3), the process proceeds to S4.

[0037] In S4, the determination unit 12 determines whether the combination obtained in S2 has changed from the combination stored in the storage unit 15 at the time of the previous startup. If it has changed (YES in S4), the process proceeds to S5. If it has not changed (NO in S4), the process proceeds to S8.

[0038] In S5, the determination unit 12 determines whether the combination obtained in S2 satisfies the configuration condition 152 that has been previously stored in the storage unit 15. If it satisfies the condition (YES in S5), the process proceeds to S8. If it does not satisfy the condition (NO in S5), the process proceeds to S6.

[0039] Here, we will explain a specific example of the processing in S5. For example, suppose the combination obtained in S2 is the state of the configuration management table 151 as exemplified in Figure 5. In this case, the condition number "1" in configuration condition 152 is not satisfied because the capacity of inverter unit 2b, which is connected in order "2", is greater than the capacity of inverter unit 2a, which is connected in order "1". Also, the condition number "2" in configuration condition 152 is not satisfied because the capacity of inverter unit 2b, which is connected in order "2", is "200W", and the capacity of servo motor 3b connected to inverter unit 2b is "400W". Furthermore, the condition number "3" in configuration condition 152 is satisfied because the sum of the capacities of inverter units 2a, 2b, and 2c is "800W". Also, the condition number "4" in configuration condition 152 is not satisfied because the input voltage of inverter unit 2c, which is connected in order "3", is "200V". The determination unit 12 should perform a negative determination if at least one of the constituent conditions 152 is not met.

[0040] In S6, the prohibition unit 14 prohibits the supply of drive current from the inverter unit 2 to the servo motor 3. In S7, the output unit 13 outputs an alarm indicating that the combination of the inverter unit 2 and the servo motor 3 does not meet the configuration conditions.

[0041] In S8, the subsequent startup process in the servo system 100 is executed because the combination of inverter unit 2 and servo motor 3 has not changed from the previous configuration, or the combination of inverter unit 2 and servo motor 3 satisfies the configuration conditions.

[0042] <Effects of the Embodiment> In this embodiment, the configuration conditions for the combination of the inverter unit 2 and the servo motor 3 in the servo system 100 are stored in advance in the storage unit 15. When the servo system 100 is started, the acquisition unit 11 acquires the combination of the inverter unit 2 and the servo motor 3, and the determination unit 12 determines whether or not the combination satisfies the configuration conditions. If it is determined that the configuration conditions are not met, the output unit 13 outputs an alarm. Therefore, according to this embodiment, it is possible to easily detect a servo system 100 configuration that does not satisfy the configuration conditions without having to check design drawings or the like.

[0043] In this embodiment, if the determination unit 12 determines that the configuration conditions are not met, the supply of drive current from the inverter unit 2 to the servo motor 3 is prohibited. Therefore, according to this embodiment, it is possible to prevent dangerous power supply that may occur when a combination of inverter unit 2 and servo motor 3 that does not meet the configuration conditions is used.

[0044] In this embodiment, even if the combination of inverter unit 2 and servo motor 3 is changed from the previous startup configuration, if the current startup configuration (modified configuration) satisfies the configuration conditions, the output of the alarm by the output unit 13 and the prohibition of the supply of drive current by the prohibition unit 14 are suppressed. Therefore, according to this embodiment, the configuration of the servo system 100 can be flexibly changed as long as the configuration conditions are met.

[0045] <Variation> Furthermore, if the servo system 100 is changed from the combination of inverter unit 2 and servo motor 3 used during the previous startup, the output unit 13 may output an alarm or the prohibition unit 14 may prohibit the supply of drive current. By adopting such a configuration, it is possible to detect changes in configuration from a configuration that has already been proven to be safe to operate, and to deter unsolicited configuration changes.

[0046] In the embodiments described above, the case in which a servo motor 3 is used as the electric motor was explained, but other electric motors may also be used. For example, induction motors or DC motors may be used as electric motors in the embodiments.

[0047] In this embodiment, a servo motor 3 may be connected to the converter unit 1, and the converter unit 1 may supply drive current to the servo motor 3 connected to the converter unit 1. In other words, the converter unit 1 may also include the functions of the inverter unit 2.

[0048] The embodiments and variations disclosed above can be combined in any way.

[0049] <Note 1> Multiple control units (2) that supply drive current to the corresponding electric motor (3), The system comprises a management unit (1) connected to the aforementioned plurality of control units, The aforementioned management unit (1) is At startup, the combination of the upper limit of the drive current that each of the connected control units (2) can supply and the capacity of the electric motor (3) associated with each of the control units (2) is obtained. The system determines whether the aforementioned combination satisfies the configuration conditions (152) related to the combination of the upper limit of the drive current and the capacity of the motor, which are stored in the storage unit (15) beforehand. If the above combination does not satisfy the above configuration condition (152), an alarm is output. Control system (100). [Explanation of Symbols]

[0050] 1. Converter Unit 2. Inverter Unit 2a ··Inverter Unit 2b. Inverter Unit 2c Inverter Unit 3. Servo motor 3a. Servo motor 3b. Servo motor 3c... Servo motor 5··PLC 11... Acquisition part 12... Judgment section 13. Output section 14...Prohibited part 15...Storage section 100 Servo System 113...Other unit connection port 151. Configuration Management Table 152. Configuration conditions 200...control circuit 101. Control circuit 201...Control circuit 201a Control Circuit 201b...control circuit 201c...control circuit 221 ··Upstream connection terminal 222 ·· Downstream connection port B1...Interior Bath

Claims

1. Multiple control units that supply drive current to the corresponding electric motor, The system comprises a management unit connected to the plurality of control units, The aforementioned multiple control units are connected in a line from upstream to downstream. The aforementioned management unit is At startup, the combination of the upper limit of the drive current that each of the connected control units can supply, the capacity of the motor associated with each of the control units, and the connection order of the control units connected in a line from upstream to downstream is obtained. The system determines whether the aforementioned combination satisfies the configuration conditions related to the combination of the upper limit of the drive current and the capacity of the motor, which are stored in the memory unit in advance, and the connection order of the plurality of control units from the upstream to the downstream. If the above combination does not satisfy the above configuration conditions, an alarm is output. The above configuration condition includes the fact that the capacity of the control unit connected to the upstream side is greater than or equal to the capacity of the control unit connected to the downstream side. Control system.

2. The management unit prohibits the supply of the drive current by the plurality of control units if the combination does not satisfy the configuration conditions. The control system according to claim 1.

3. The management unit outputs the alarm if the combination acquired during the previous startup is different from the combination acquired during the current startup. The control system according to claim 1 or 2.

4. The management unit prohibits the supply of the drive current by the plurality of control units if the combination acquired during the previous startup is different from the combination acquired during the current startup. The control system according to any one of claims 1 to 3.

5. The management unit, if the combination acquired at the current startup satisfies the configuration conditions, combines the combination acquired at the previous startup with the combination acquired at the current startup. Even if the values ​​differ, the output of the alarm will be suppressed. The control system according to any one of claims 1 to 4.

6. The management unit, if the combination acquired at the current startup satisfies the configuration conditions, permits the supply of the drive current by the plurality of control units, even if the combination acquired at the previous startup is different from the combination acquired at the current startup. The control system according to any one of claims 1 to 5.

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