Servo driver and adjustment method for servo driver

Abstract

To provide a servo driver and an adjustment method for the servo driver which can suppress variation in output characteristics.SOLUTION: A servo driver comprises: a power supply unit which outputs predetermined voltage; a power module which outputs drive voltage to a servo motor and of which the voltage variation amount of the drive voltage per unit time varies according to voltage supplied from the power supply unit; power supply wiring which connects the power supply unit with the power module; and an adjustment unit which is arranged on the power supply wiring to adjust the voltage supplied from the power supply unit to the power module.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a servo driver and a method for adjusting the servo driver. [Background technology]

[0002] Servo drivers use an Intelligent Power Module (IPM) in the circuit that supplies drive voltage to the servo motor. Patent Document 1 proposes a technology that adjusts noise and switching loss generated within the IPM by adding connection terminals to the IPM and adjusting the capacitors and resistors connected to the connection terminals. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-051068 Summary of the Invention [Problem to be solved by the invention]

[0004] Because IPMs are modularized, it is not possible to adjust dv / dt, so even for servo drivers of the same model, individual differences in IPMs can cause variations in the output characteristics of servo drivers.

[0005] An object of one aspect of the disclosed technology is to provide a servo driver and a method for adjusting a servo driver that can suppress variations in output characteristics. [Means for solving the problem]

[0006] One aspect of the disclosed technology is exemplified by the following servo driver: The servo driver includes: a power supply unit that outputs a predetermined voltage, a power module that outputs a drive voltage to a servo motor, where the amount of voltage change per unit time of the drive voltage varies depending on the voltage supplied from the power supply unit, a power supply wiring that connects the power supply unit and the power module, and an adjustment unit that is arranged on the power supply wiring and adjusts the voltage supplied from the power supply unit to the power module.

[0007] In this servo driver, the adjustment unit adjusts the voltage change per unit time of the power module to a desired value, thereby suppressing variations in output characteristics due to individual differences between power modules.

[0008] The servo driver may further include the following feature: the adjustment unit includes a variable resistor, and the adjustment unit adjusts the voltage supplied to the power module by adjusting the resistance value of the variable resistor. The servo driver having such a feature can adjust the amount of voltage change per unit time of the power module to a desired value by the simple operation of adjusting the resistance value of the variable resistor.

[0009] The servo driver may further include the following feature: the adjustment unit includes a receiving unit that receives a voltage command value, and a resistance adjustment unit that adjusts the resistance value of the variable resistor so that the voltage supplied to the power module matches the command value. The servo driver having such features enables, for example, a user of the servo driver to adjust the amount of voltage change per unit time of the power module to a desired value.

[0010] The servo driver may further include the following features: The servo driver includes a first output element for the upper arm and a second output element for the lower arm. The power supply wiring includes a first power supply wiring connecting the power supply unit and the first output element, and a second power supply wiring connecting the power supply unit and the second output element. The adjustment unit includes a first adjustment unit arranged on the first power supply wiring to adjust the voltage supplied to the first output element, and a second adjustment unit arranged on the second power supply wiring to adjust the voltage supplied to the second output element. This servo driver with these features can adjust the amount of voltage change per unit time of the power module to a desired value for each of the upper arm and the lower arm. [Effects of the Invention]

[0011] According to the disclosed technology, variations in the output characteristics of the servo driver can be suppressed. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram illustrating an example of a servo driver according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of a voltage adjustment circuit according to an embodiment. [Figure 3] FIG. 3 is a diagram illustrating an example of a hardware configuration of a control unit according to the embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of a processing block of the control unit according to the embodiment. [Figure 5] FIG. 5 is a diagram illustrating an example of a processing flow for adjusting the output characteristics of the servo driver according to the embodiment. [Figure 6] FIG. 6 is a diagram illustrating an example of a servo driver according to a comparative example. [Figure 7] FIG. 7 is a diagram illustrating the output characteristics of the drive voltage in the servo driver according to the embodiment. [Figure 8] FIG. 8 is a diagram illustrating the output characteristics of the drive voltage in a servo driver according to a comparative example. [Figure 9] FIG. 9 is a diagram illustrating an example of a servo driver according to a first modified example. DETAILED DESCRIPTION OF THE INVENTION

[0013] <Application example> An application example of the present invention will be described. As shown in FIG. 1 , a servo driver 1 according to this application example includes a power transformer 10, a voltage adjustment circuit 20, an IPM 30, and a power supply line P1. The power transformer 10 controls the voltage supplied from a commercial power source to a predetermined voltage and supplies the voltage to a drive voltage generation circuit 300 of the IPM 30 via the power supply line P1. The IPM 30 is a power module that supplies a drive voltage to a servo motor. The amount of voltage change per unit time (dv / dt) of this drive voltage varies depending on the voltage supplied from the power transformer 10 to the drive voltage generation circuit 300. The power supply line P1 is a line that supplies voltage from the power transformer 10 to the drive voltage generation circuit 300 of the IPM 30.

[0014] Here, because the IPM 30 is modularized, it is not possible to change dv / dt within the IPM 30. Therefore, even if the servo drivers 1 are of the same model, variations in the output of the IPM 30 (i.e., the output of the drive voltage generation circuit 300) may occur due to individual differences in the IPM 30. Due to such variations, for example, even when a servo driver installed in an existing servo system is replaced with a servo driver of the same model, the output gain parameters set in the existing servo driver cannot be reused. Therefore, even when replacing with a servo driver of the same model, it is necessary to adjust the output gain parameters.

[0015] Therefore, in the servo driver 1 according to this application example, a voltage adjustment circuit 20 is arranged on the power supply wiring P1. The voltage adjustment circuit 20 is a circuit that adjusts the voltage supplied from the power transformer 10 to the drive voltage generation circuit 300 of the IPM 30. When the voltage supplied to the drive voltage generation circuit 300 is adjusted by the voltage adjustment circuit 20, the dv / dt of the IPM 30 is adjusted as a result. In such a servo driver 1, the voltage adjustment circuit 20 adjusts the voltage of the IPM 30. By adjusting the voltage supplied to the drive voltage generating circuit 300, it is possible to suppress variations in output characteristics when the same output gain parameters are set for servo drivers of the same model.

[0016] <Embodiment> Hereinafter, an embodiment will be described with reference to the drawings. Fig. 1 is a diagram showing an example of a servo driver 1 according to an embodiment. As described in the application example, the servo driver 1 includes a power transformer 10, a voltage adjustment circuit 20, an IPM 30, and a power supply line P1.

[0017] The power transformer 10 supplies a voltage to the drive voltage generation circuit 300 of the IPM 30 via the power supply line P1 based on the voltage supplied from the commercial power supply. The voltage supplied by the power transformer 10 to the drive voltage generation circuit 300 of the IPM 30 is controlled to a predetermined voltage. The predetermined voltage is, for example, 20 V. The power transformer 10 may supply a voltage to the drive voltage generation circuit 300 based on a voltage supplied from a constant-voltage power supply or an auxiliary power supply instead of the commercial power supply.

[0018] The voltage adjustment circuit 20 adjusts the voltage input from the power transformer 10 to a desired voltage and outputs it to the drive voltage generation circuit 300. The voltage adjustment range by the voltage adjustment circuit 20 is, for example, within the operating voltage range of the IPM 30 (i.e., within the operating voltage range of the drive voltage generation circuit 300). The operating voltage range of the IPM 30 can be, for example, a range from +13.5 V to +20 V. The drive voltage generation circuit 300 of the IPM 30 supplies a drive voltage to, for example, a servo motor based on the voltage adjusted by the voltage adjustment circuit 20.

[0019] 2 is a diagram illustrating an example of a voltage adjustment circuit 20 according to an embodiment. The voltage adjustment circuit 20 includes an adjustment circuit 21 and a control unit 22.

[0020] The adjustment circuit 21 has a three-terminal regulator 211, a variable resistor R1, and smoothing capacitors C1 and C2. The three-terminal regulator 211 adjusts the voltage input from the power transformer 10 to a voltage according to the resistance value of the variable resistor R1, and outputs the adjusted voltage to the drive voltage generation circuit 300 of the IPM 30. The resistance value of the variable resistor R1 is controlled according to a control signal from the control unit 22 via a signal line L1, for example.

[0021] The control unit 22 is a computer that controls the resistance value of the control unit 22 via the signal line L1. The control unit 22 outputs a control signal to the control unit 22 to change the resistance value of the control unit 22 in accordance with, for example, a user instruction.

[0022] <Hardware configuration of control unit 22> 3 is a diagram showing an example of a hardware configuration of the control unit 22 according to the embodiment. The control unit 22 includes a CPU 221, a main memory unit 222, an auxiliary memory unit 223, a connection terminal 224, an input / output unit 225, and a connection bus B1. The CPU 221, the main memory unit 222, the auxiliary memory unit 223, the connection terminal 224, and the input / output unit 225 are connected to each other by the connection bus B1.

[0023] The CPU 221 is also called a microprocessor unit (MPU) or a processor. The CPU 221 is not limited to a single processor, and may have a multi-processor configuration. Furthermore, a single CPU 221 connected via a single socket may have a multi-core configuration. At least a part of the processing performed by the CPU 221 may be performed by a processor other than the CPU 221, for example, a dedicated processor such as a digital signal processor (DSP), a graphics processing unit (GPU), a numerical calculation processor, a vector processor, or an image processing processor. Furthermore, at least a part of the processing performed by the CPU 221 may be performed by an integrated circuit (IC) or other digital circuit. Furthermore, at least a part of the processing performed by the CPU 221 may be performed by a dedicated processor such as a digital signal processor (DSP), a graphics processing unit (GPU), a numerical calculation processor, a vector processor, or an image processing processor. At least a part of the control unit 22 may include an analog circuit. In the control unit 22, the CPU 221 loads the program stored in the auxiliary storage unit 223 into the work area of ​​the main storage unit 222, and controls the peripheral devices through the execution of the program. This allows the control unit 22 to execute processing that meets a predetermined purpose. The main storage unit 222 and the auxiliary storage unit 223 are recording media that the CPU 221 can read.

[0024] The main storage unit 222 is exemplified as a storage unit that is directly accessed by the CPU 221. The main storage unit 222 includes a random access memory (RAM) and a read only memory (ROM).

[0025] The auxiliary storage unit 223 stores various programs and various data on a readable and writable recording medium. The auxiliary storage unit 223 is also called an external storage device. The auxiliary storage unit 223 stores an operating system (OS), various programs, various tables, etc.

[0026] The auxiliary storage unit 223 is, for example, an erasable programmable ROM (EPROM), a solid state drive (SSD), a hard disk drive (HDD), or the like.

[0027] For example, the signal line L1 is connected to the connection terminal 224. The CPU 221 outputs a control signal to the variable resistor R1 via the connection terminal 224 and the signal line L1.

[0028] The input / output unit 225 includes an input unit that accepts input from a user and an output unit that outputs the execution results of the CPU 221. Examples of the input unit include input devices such as a keyboard, a mouse, a trackball, a touch panel, and a microphone. Examples of the output unit include output devices such as a display, a status lamp, and a speaker.

[0029] <Processing blocks of the control unit 22> 4 is a diagram showing an example of a processing block of the control unit 22 according to the embodiment. The control unit 22 includes a reception unit 2221 and a voltage control unit 2222. The control unit 22 executes the processes of each unit, such as the reception unit 2221 and the voltage control unit 2222, by the CPU 221 executing a computer program deployed in an executable manner in the main storage unit 222.

[0030] The receiving unit 2221 receives a voltage command value input from a user. The voltage control unit 2222 outputs a control signal for controlling the resistance value of the variable resistor R1 so that the output voltage output from the voltage adjustment circuit 20 to the drive voltage generation circuit 300 of the IPM 30 becomes the command value received by the receiving unit 2221. For example, the voltage control unit 2222 may store in advance in the auxiliary storage unit 223 a correspondence relationship between the output voltage of the voltage adjustment circuit 20 and the resistance value of the variable resistor R1 and determine the resistance value of the variable resistor R1 corresponding to the command value by referring to the correspondence relationship. For example, the user can control the IPM 30 to achieve a desired dv / dt by adjusting the command value input to the receiving unit 2221 while measuring the dv / dt of the IPM 30.

[0031] <How to adjust the output characteristics of Servo Driver 1> 5 is a diagram showing an example of a processing flow for adjusting the output characteristics of the servo driver 1 according to the embodiment. Hereinafter, an example of a processing flow for adjusting the output characteristics of the servo driver 1 will be described with reference to FIG.

[0032] In step S1, the dv / dt of the voltage output by the IPM 30 is measured. For example, an oscilloscope is used to measure the dv / dt. If t is the desired value (YES in step S2), the process ends. If the dv / dt measured in step S1 is not the desired value (NO in step S2), the process proceeds to step S3.

[0033] In step S3, the receiving unit 2221 receives a voltage command value from the user. In step S4, the voltage control unit 2222 outputs a control signal to control the resistance value of the variable resistor R1 so that the output voltage output by the voltage adjustment circuit 20 to the drive voltage generation circuit 300 of the IPM 30 becomes the command value received in step S3. The processes from step S1 to step S4 are repeatedly executed until the dv / dt of the IPM 30 reaches a desired value.

[0034] <Comparative Example> 6 is a diagram showing an example of a servo driver 8 according to a comparative example. The servo driver 8 includes a power transformer 81, an IPM 82, and a power supply line P81. In the servo driver 8, the power transformer 81 supplies a predetermined voltage based on the voltage supplied from a commercial power source to a drive voltage generation circuit 820 of the IPM 82 via the power supply line P81. The drive voltage generation circuit 820 of the IPM 82 supplies a drive voltage to a servo motor based on the voltage supplied from the power transformer 81, for example.

[0035] <Comparison between the embodiment and the comparative example> Here, the servo driver 1 according to the embodiment will be compared with the servo driver 8 according to the comparative example. Fig. 7 is a diagram illustrating the output characteristics of the drive voltage in the servo driver 1 according to the embodiment. Fig. 8 is a diagram illustrating the output characteristics of the drive voltage in the servo driver 8 according to the comparative example. The vertical axis of Figs. 7 and 8 illustrates voltage, and the horizontal axis illustrates time.

[0036] 7A and 7B illustrate the output characteristics of servo drivers of the same model that incorporate the servo driver 1 according to the embodiment. The servo driver 1 whose output characteristics are illustrated in FIG. 7A and the servo driver 1 whose output characteristics are illustrated in FIG. 7B have their voltage adjustment circuits 20 adjusted to obtain the same output characteristics. On the other hand, FIGS. 8A and 8B illustrate the output characteristics of servo drivers of the same model that incorporate the servo driver 8 according to the comparative example.

[0037] Comparing FIG. 7A and FIG. 7B, the time it takes for the voltage to change from V1 to V2 is T1 in both cases. That is, in the servo driver 1 according to the embodiment, if the model is the same, the dv / dt is adjusted to be the same. Also, comparing FIG. 8A and FIG. 8B, in FIG. 8A, the time it takes for the voltage to change from V1 to V2 is T2, while in FIG. 8B, the time it takes for the voltage to change from V1 to V2 is T3, which is different from T2. That is, in the servo driver 8 according to the comparative example, individual differences occur in dv / dt.

[0038] According to this embodiment, the voltage adjustment circuit 20 is adjusted so that the dv / dt of the IPM 30 becomes a desired value. Therefore, this embodiment suppresses variations in the dv / dt of the IPM 30 due to individual differences. Furthermore, this embodiment enables adjustment of the dv / dt of the IPM 30 by the simple operation of adjusting the resistance value of the variable resistor R1.

[0039] (First Modification) 9 is a diagram showing an example of a servo driver 1A according to a first modification. The servo driver 1A according to the first modification differs from the servo driver 1 in that it includes an IPM 30A instead of the IPM 30, and voltage adjustment circuits 20A and 20B instead of the voltage adjustment circuit 20.

[0040] In the IPM 30A, the drive voltage generating circuit 300 includes a high voltage IC (HVIC) 31 for the upper arm and a low voltage IC (LVIC) 3 for the lower arm. 2. HVIC31 is an integrated circuit that controls the voltage of the upper arm. LVIC32 is an integrated circuit that controls the voltage of the lower arm. Power is supplied to the HVIC31 from the power transformer 10 via a power supply line P1A. Power is supplied to the LVIC32 from the power transformer 10 via a power supply line P1B. The power supply line P1A is a line that supplies voltage from the power transformer 10 to the HVIC31. The power supply line P1B is a line that supplies voltage from the power transformer 10 to the LVIC32.

[0041] A voltage adjustment circuit 20A is arranged on the power supply wiring P1A. Furthermore, a voltage adjustment circuit 20B is arranged on the power supply wiring P1B. The voltage adjustment circuit 20A is a circuit that adjusts the voltage supplied from the power transformer 10 to the HVIC 31. The voltage adjustment circuit 20B is a circuit that adjusts the voltage supplied from the power transformer 10 to the LVIC 32.

[0042] 5 is executed for each of the voltage adjustment circuits 20A and 20B in the servo driver 1A. As a result, in the servo driver 1A, the voltage adjustment circuit 20A adjusts the voltage input to the HVIC 31, and the voltage adjustment circuit 20B adjusts the voltage input to the LVIC 32. Therefore, the servo driver 1A according to the first modification can adjust the dv / dt to the desired value for each of the HVIC 31 for the upper arm and the LVIC 32 for the lower arm.

[0043] <Other variations> In the embodiment described above, the voltage adjustment circuit 20 includes the variable resistor R1. However, the voltage adjustment circuit 20 may include a resistor having a fixed resistance value instead of the variable resistor R1. That is, the voltage adjustment circuit 20 may include a resistor having a resistance value that provides a desired dv / dt instead of the variable resistor R1. In addition to including the variable resistor R1, the voltage adjustment circuit 20 includes the receiving unit 2221 and the voltage control unit 2222, so that the user can adjust the dv / dt of the IPM 30 to the desired dv / dt when installing the servo driver 1.

[0044] In the embodiment described above, the voltage adjustment circuit 20 includes the control unit 22, but the control unit 22 may be omitted. In this case, the resistance value of the variable resistor R1 of the adjustment circuit 21 may be adjusted while measuring the dv / dt of the IPM 30.

[0045] The embodiments and modifications disclosed above can be combined with each other.

[0046] Supplementary notes regarding the disclosed technology are given with reference numerals. <Appendix 1> a power supply unit (10) that outputs a predetermined voltage; a power module (30, 300) that outputs a drive voltage to a servo motor, wherein a voltage change amount of the drive voltage per unit time varies in accordance with a voltage supplied from the power supply unit (10); a power supply wiring (P1) connecting the power supply unit (10) and the power module (30, 300); an adjusting unit (20) disposed on the power supply wiring (P1) and adjusting the voltage supplied from the power supply unit (10) to the power module (30, 300); Servo driver (1). <Appendix 2> The adjustment unit (20) includes a variable resistor (R1), The adjusting unit (20) adjusts the voltage to be supplied to the power module (30, 300) by adjusting the resistance value of the variable resistor (R1). A servo driver (1) as described in Appendix 1. <Appendix 3> The adjustment unit (20) a reception unit (2221) that receives a voltage command value; a resistance adjusting unit (2222) that adjusts the resistance value of the variable resistor (R1) so that the voltage supplied to the power module (30, 300) matches the command value, Servo driver as described in Appendix 2. <Appendix 4> The power module (30, 300) includes a first output element (31) for an upper arm and a second output element (32) for a lower arm, the power supply wiring (P1) includes a first power supply wiring (P1A) that connects the power supply unit (10) and the first output element (31) and a second power supply wiring (P1B) that connects the power supply unit (10) and the second output element (32); The adjustment unit (20) includes a first adjustment unit (20A) arranged on the first power supply wiring (P1A) and adjusting a voltage to be supplied to the first output element (31), and a second adjustment unit (20B) arranged on the second power supply wiring (P1B) and adjusting a voltage to be supplied to the second output element (32). 4. A servo driver according to any one of claims 1 to 3. <Appendix 5> A method for adjusting a servo driver (1) including: a power supply unit (10) that outputs a predetermined voltage; a power module (30, 300) that outputs a drive voltage to a servo motor, the power module (30, 300) having a voltage change amount per unit time of the drive voltage that varies according to the voltage supplied from the power supply unit (10); and an adjustment unit (20) that is arranged on a power supply wiring (P1) that connects the power supply unit (10) and the power module (30, 300), The voltage change amount per unit time of the driving voltage is measured (FIG. 6, step S1); The voltage supplied from the power supply unit to the power module is adjusted by the adjustment unit so that the amount of voltage change per unit time becomes a desired value (FIG. 6, steps S2 to S4); How to adjust a servo driver. [Explanation of symbols]

[0047] 1. Servo driver 1A Servo Driver 8. Servo driver 81 Power transformer 82··IPM 10. Power transformer 20. Voltage regulation circuit 20A voltage regulation circuit 20B Voltage Regulator Circuit 21·Adjustment circuit 22 Control section 30··IPM 30A IPM 31··HVIC 32··LVIC 211 Three-terminal regulator 221 CPU 222...Main memory 223...Auxiliary storage section 224 Connection terminal 225...Input / output section 300··Drive voltage generation circuit 820··Drive voltage generation circuit 2221··Reception Department 2222 Voltage control section B1 Connecting bus C1 Capacitor C2 Capacitor L1...Signal line R1 Variable resistor P1 Power supply wiring P1A Power supply wiring P1B Power supply wiring P81 Power supply wiring

Claims

1. a power supply unit that outputs a predetermined voltage; a power module that outputs a drive voltage to a servo motor, wherein a voltage change amount of the drive voltage per unit time varies in accordance with the voltage supplied from the power supply unit; a power supply wiring that connects the power supply unit and the power module; an adjusting unit that is disposed on the power supply wiring and adjusts the voltage supplied from the power supply unit to the power module, Servo driver.

2. the adjustment unit includes a variable resistor, the adjusting unit adjusts the voltage supplied to the power module by adjusting the resistance value of the variable resistor. The servo driver according to claim 1 .

3. The adjustment unit a receiving unit that receives a voltage command value; a resistance adjusting unit that adjusts the resistance value of the variable resistor so that the voltage supplied to the power module coincides with the command value, 3. The servo driver according to claim 2.

4. the power module includes a first output element for an upper arm and a second output element for a lower arm, the power supply wiring includes a first power supply wiring that connects the power supply unit and the first output element, and a second power supply wiring that connects the power supply unit and the second output element, the adjusting unit includes a first adjusting unit arranged on the first power supply wiring and adjusting a voltage supplied to the first output element, and a second adjusting unit arranged on the second power supply wiring and adjusting a voltage supplied to the second output element.

4. A servo driver according to claim 1.

5. A method for adjusting a servo driver including: a power supply unit that outputs a predetermined voltage; a power module that outputs a drive voltage to a servo motor, wherein a voltage change amount per unit time of the drive voltage varies according to the voltage supplied from the power supply unit; and an adjustment unit that is disposed on a power supply wiring that connects the power supply unit and the power module, measuring the amount of voltage change per unit time of the driving voltage; adjusting the voltage supplied from the power supply unit to the power module by the adjusting unit so that the amount of voltage change per unit time becomes a desired value; How to adjust a servo driver.

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