TWI736106B - Servo motor control device - Google Patents

Abstract

The invention reduces the occurrence of misoperation in the application system with the servo motor. The servo motor control device controls the servo motor based on the input command value input from the host device 100. The servo motor control device includes: a control processing unit 20 that compares an input command value with a command limit value to generate a compared command value, and generates a current command value and a voltage command value based on the compared command value; and a power converter, It supplies electric power to the servo motor M based on the current command value and the voltage command value. When the input command value is within the range of the command limit value, the control processing unit 20 uses the input command value as the compared command value, and when the input command value is outside the command limit value range, the command limit value is used as the comparison After the instruction value.

Description

Servo motor control device

The invention relates to a servo motor control device.

Patent Document 1 discloses a motor control device that overwrites the command value when the command value from the upper device is incorrect. According to Patent Document 1, the suppression of the terminal voltage of the motor is performed by flowing a negative current on the d-axis so that the maximum output voltage of the converter does not exceed the terminal voltage of the permanent magnet synchronous motor.

Specifically, the voltage command value input to the converter is compared with the terminal voltage upper limit set based on the maximum output voltage of the converter, and when the voltage command value exceeds the terminal voltage upper limit, d The axis current component is switched to the direction of increasing in the negative direction. When the voltage command value is below the upper limit of the terminal voltage, the d-axis current component is switched to the direction of decreasing in the negative direction. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2005/093943

[The problem to be solved by the invention]

Generally, the servo motor control device controls the servo motor based on the command from the upper device. However, due to communication errors with the upper device or the generation of loopholes in the upper device, etc., there are situations in which abnormal command values that are not normally present are output to the servo motor control device. In this case, it is impossible to judge on the side of the servo motor control device whether the input command value is the correct value, and whether it should act according to the input value.

In Patent Document 1, the command value from the upper device is also set to be correct, and the voltage command value generated inside the converter is compared with the maximum output voltage used to protect the converter. In Patent Document 1, even if the command value input from the host device is wrong due to some reasons, the current and voltage command values to protect the converter will be generated. However, there is an application system where the motor is installed (suppression Device, etc.) may cause malfunction. There is a risk of damage to the device equipped with the motor or damage to the components (molds, etc.) used in the device due to malfunction.

Therefore, the object of the present invention is to provide a servo motor control device that reduces the occurrence of malfunctions in an application system with a servo motor. [Technical means to solve the problem]

Among the inventions disclosed in this case, a brief description of the outline of representative inventions is as follows.

The servo motor control device of the representative embodiment of the present invention controls the servo motor based on the input command value input from the host device. The servo motor control device includes: a control processing unit that compares an input command value with a command limit value to generate a command value, and generates a current command value and a voltage command value based on the command value; and a power converter based on the current command value And the voltage command value to supply power to the servo motor. The control processing unit uses the input command value as the command value when the input command value is within the range of the command limit value, and uses the command limit value as the command value when the input command value is outside the range of the command limit value. [Effects of Invention]

Among the inventions disclosed in this application, a brief description of the effects obtained by the representative inventions is as follows.

That is, according to the representative embodiment of the present invention, it is possible to reduce the occurrence of malfunctions in an application system with a servo motor.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each embodiment described below is an example for realizing the present invention, and does not limit the technical scope of the present invention. Furthermore, in the embodiments, components with the same function are marked with the same symbols, and repeated descriptions thereof are omitted except for special needs. (Embodiment 1) ＜Constitution of servo motor control device＞

Fig. 1 is a block diagram showing an example of the configuration of a servo motor control device according to the first embodiment of the present invention. As shown in FIG. 1, the servo motor control device 1 includes a command value input circuit 10, a control processing unit 20, a power converter 30, and a gate driver 70. "Command value input circuit"

The input command value is input to the command value input circuit 10 from the host device 100. The input command value is used to control the parameter of the servo motor M. The input command value corresponding to the operation mode of the application system with the servo motor M is sequentially input to the command value input circuit 10. In this embodiment, the speed command value is input as the input command value. The speed command value is a parameter related to the rotation speed of the servo motor M, expressed by the angular speed of the rotating shaft, etc.

The input command value is input to the command value input circuit 10 as an analog signal such as an analog voltage, for example. The input analog signal is converted into a digital signal by an AD (analog to digital) conversion circuit 11, and is output to the control processing unit 20.

In addition, the command value input circuit 10 may be connected to the host device 100 via a network such as RT-485 or Ethernet (registered trademark), for example. In this case, a digital signal is sent and received between the command value input circuit 10 and the host device 100.

"Control Processing Department" Fig. 2 is a block diagram showing an example of the configuration of the control processing unit in the first embodiment of the present invention. In addition, in FIG. 2, the upper-level device 100, the control processing unit 20, and the command value input circuit 10 are omitted.

The control processing unit 20 generates a function block for controlling the current command value and the voltage command value of the servo motor M based on the input command value input from the host device 100. As shown in FIG. 2, the control processing unit 20 includes a speed command value determination processing unit 23, a speed control processing unit 24, a torque command value determination processing unit 25, a torque control processing unit 26, and a limit value table 29.

The control processing unit 20 has a processor, a memory, and the like. The memory stores the programs for operating the servo motor control device 1, the operation mode of the application system, and the like. Each functional block included in the control processing unit 20 is realized by the processor executing the program read from the memory. In addition, the control processing unit 20 may also be composed of an ASIC (application specific integrated circuit), an FPGA (field-programmable gate array, field-programmable gate array), etc., which implement the above-mentioned functional blocks.

The speed command value judgment processing unit 23 is a functional block that judges whether the input speed command value is a normal value. Specifically, the speed command value determination processing unit 23 compares the input speed command value with the speed command limit value stored in the limit value table 29. The speed command value determination processing unit 23 switches the speed command limit value to be compared in each period according to the operation mode.

When the speed command value is within the range of the speed command limit value selected as the comparison target, the speed command value judgment processing unit 23 judges it as a normal value, and outputs the speed command value as the compared speed command value to the speed control process Department 24.

In contrast, when the speed command value is out of the range of the selected speed command limit value, the speed command value determination processing unit 23 determines that the speed command value is an abnormal value, and uses the speed command limit value as the compared speed command value And output to the speed control processing unit 24. At this time, the speed command value determination processing unit 23 outputs an abnormality notification indicating that the input speed command value is an abnormal value to the host device 100. The abnormality notification may also include information about the period during which the abnormality occurred in the specific operation mode.

The position information of the servo motor M detected by the position detector EN is input to the speed command value determination processing unit 23. The speed command value determination processing unit 23 can switch the speed command limit value based on the position information of the servo motor M.

In addition, the sensor information of the application system detected by the sensor AS is input to the speed command value determination processing unit 23. The speed command value determination processing unit 23 can use the sensor information to switch the speed command limit value. The sensor information includes position information of components in the application system driven by the servo motor M, for example. As the member, for example, a slider mounted on a pressing machine and a mold attached to the slider can be cited. The position information of the component detected by the sensor AS can identify each period in the operation mode.

The speed control processing unit 24 is a functional block that generates a torque command value based on the compared speed command value. Specifically, the speed control processing unit 24 calculates the torque corresponding to the compared speed command value input from the speed command value determination processing unit 23. Specifically, the speed control processing unit 24 calculates the torque applied to the motor shaft so that the rotation speed of the servo motor M becomes the speed specified by the compared speed command value (speed command value or speed command limit value). The speed control processing unit 24 outputs the calculated torque as a torque command value to the torque command value determination processing unit 25.

The speed command value determination processing unit 23 sequentially inputs the speed command value after comparison corresponding to each period in the operation mode to the speed control processing unit 24. Then, the speed control processing unit 24 sequentially outputs the corresponding torque command values to the torque command value determination processing unit 25 based on the input compared speed command values.

The torque command value determination processing unit 25 is a functional block that determines whether the input torque command value is a normal value. Specifically, the torque command value determination processing unit 25 compares the input torque command value with the torque command limit value stored in the limit value table 29. The torque command value determination processing unit 25 switches the torque command limit value to be compared in accordance with the operation mode.

When the torque command value is within the range of the torque command upper limit value selected as the comparison target, the torque command value determination processing unit 25 determines that it is a normal value, and uses the torque command value as the compared torque command value. It is output to the torque control processing unit 26.

In contrast, when the torque command value is out of the range of the torque command limit value selected as the comparison target, the torque command value determination processing unit 25 determines that the torque command value is an abnormal value, and sets the torque command limit value It is output to the torque control processing unit 26 as a torque command value after comparison. At this time, the torque command value determination processing unit 25 outputs an abnormality notification indicating that the input torque command value is an abnormal value to the host device 100. The abnormality notification output from the torque command value determination processing unit 25 may also include information specifying the period during which the abnormality occurred in the operation mode.

The torque command value determination processing unit 25 also inputs the position information of the servo motor M detected by the position detector EN. The torque command value determination processing unit 25 can switch the torque command limit value based on the position information of the servo motor M.

In addition, the torque command value determination processing unit 25 also inputs sensor information of the application system detected by the sensor AS. The torque command value determination processing unit 25 can also use the sensor information to switch the torque command limit value.

The torque control processing unit 26 is a functional block that generates a current command value and a voltage command value based on the compared torque command value. Specifically, the torque control processing unit 26 calculates such that the torque applied to the rotating shaft of the servo motor M becomes the torque specified by the compared torque command value (torque command value or torque command limit value) The current and voltage supplied to the servo motor M. The torque control processing unit 26 outputs the calculated current and voltage to the gate driver 70 as a current command value and a voltage command value.

The torque command value determination processing unit 25 sequentially inputs the torque command value after comparison corresponding to each period in the operation mode to the torque control processing unit 26. Then, the torque control processing unit 26 sequentially outputs the corresponding current command value and voltage command value to the gate driver 70 based on the input compared torque command value.

The limit value table 29 is a table that stores various parameters related to the control of the servo motor M, such as the speed command limit value, the torque command limit value, and so on. The speed command limit value and the torque command limit value are set according to the operation mode in a way to suppress the occurrence of malfunction in the application system with the servo motor M.

"Power Conversion Machine" As shown in FIG. 1, the power converter 30 has a converter 40, a smoothing circuit 50, a converter 60, and a gate driver 70. The converter 40 is a circuit that converts the AC power supplied from the external power source 110 into a DC power source. The converter 40 uses a well-known circuit. The converter 40 is constituted by, for example, a half-wave rectifier circuit, a full-wave rectifier circuit, or the like. The smoothing circuit 50 is a circuit that smoothes the DC power generated by the converter 40. For the smoothing circuit 50, for example, a well-known circuit equipped with a capacitor or a coil is used.

The converter 60 is a circuit that converts the DC power smoothed by the smoothing circuit 50 into a 3-phase AC power. The converter 60 is provided with a pulse modulation circuit corresponding to each of the three phases of the AC power source. The pulse modulation circuit is composed of, for example, a pulse width modulation (PAM: Pulse Amplitude Modulation) circuit or a pulse amplitude modulation (PWM: Pulse Width Modulation) circuit. The pulse modulation circuit of each phase is controlled by the control signal input from the gate driver 70 described below. Thereby, the converter 60 supplies electric power based on the current command value and the voltage command value to the servo motor M.

The gate driver 70 is a circuit block that generates a control signal based on the current command value and the voltage command value output from the torque control processing unit 26. Specifically, if the current command value and the voltage command value are input, the gate driver 70 generates control signals for each phase of the pulse modulation circuit and outputs them to the converter 60.

The torque control processing unit 26 sequentially inputs the current command value and the voltage command value corresponding to each period of the operation mode to the gate driver 70. Then, the gate driver 70 sequentially outputs the control signals of the corresponding phases to the converter 60 based on the input current command value and voltage command value. Furthermore, the gate driver 70 may also be installed outside the power converter 30.

"operating system" The servo motor M is assembled in various application systems such as a press machine, and is operated by the 3-phase power supplied from the self-converter 60 to make the application system function. A position detector EN is installed near the servo motor M. The position detector EN supplies position information to the control processing unit 20 by outputting a pulse every time the servo motor M makes one revolution, for example. The control processing unit 20 can calculate the position or rotation speed of the servo motor M based on the input position information.

The sensor AS, for example, senses the position of a component in the application system driven by the servo motor M, and outputs it to the control processing unit 20 as sensor information. The sensor information includes position information of components in the application system driven by the servo motor M, for example. The control processing unit 20 can recognize the situation in the application system based on the sensor information, and switch the speed command limit value and the torque command limit value according to the situation.

＜Control method of servo motor＞ Next, the control method of the servo motor M will be described with a specific example. Fig. 3 is a diagram showing an example of the control method of the servo motor according to the first embodiment of the present invention. Fig. 3 shows a timing chart of the speed command value, the torque command value, and the current position of the servo motor M as the input command value. The timing chart of the speed command value and torque command value also shows the speed command limit value and torque command limit value in each period. The timing chart of the speed command value corresponds to the operation mode of this embodiment. The operation mode based on the speed command value can be used, for example, to control a servo motor installed in a press machine.

In the press, the slider and the mold mounted on the slider are pressed from the top dead center toward the bottom dead center of the mold fixed below the slider to perform compression processing and pressurization/regeneration of the mold cushion. After that, the slider and the mold rise from the bottom dead center to the top dead center. The pressing machine repeatedly performs the up and down movement (reciprocating movement) of the slide and the mold.

First, during the time t0-t1, the speed command value linearly increases from 0 to V0. The torque command value during this period is T0. During this period, the position of the servo motor M moves from P0 to P1. The speed command limit value during this period is VL0, and the torque command limit value is TL0.

During the period from t1 to t2, the speed command value is V0. The torque command value during this period is T1. During this period, the position of the servo motor M moves from P1 to P2. The speed command limit value during this period is VL0, and the torque command limit value is TL1.

During the time t2-t3, the speed command value linearly decreases from V0 to V1. The torque command value during this period is T2. During this period, the position of the servo motor M moves from P2 to P3. The speed command limit value during this period is VL0, and the torque command limit value is TL2. The torque command limit value TL2 is a value less than 0, and the torque command value is set to not less than the torque command limit value TL2.

During the period from t3 to t7, the speed command value is V1. The torque command value during this period changes in the order of T1(t3-t4), T3(t4-t5), T4(t5-t6), T1(t6-t7). During the period from time t3 to t7, the position of the servo motor M moves sequentially from P3 to P7. The speed command limit value during this period is VL0. The torque command limit values during this period are TL1 (t3-t4), TL3 (t4-t5), TL4 (t5-t6), and TL1 (t6-t7).

During the period from t7 to t8, the speed command value linearly increases from V1 to V0. The torque command value during this period is T0. During this period, the position of the servo motor M moves from P7 to P8. The speed command limit value during this period is VL0, and the torque command limit value is TL0.

During the period from t8 to t9, the speed command value is V0. The torque command value during this period is T1. During this period, the position of the servo motor M moves from P8 to P9. The speed command limit value during this period is VL0, and the torque command limit value is TL1.

During the period from t9 to t10, the speed command value linearly decreases from V0 to V0. The torque command value during this period is T2. During this period, the position of the servo motor M moves from P9 to P10. The speed command limit value during this period is VL0, and the torque command limit value is TL2.

In the press, the slider and the mold are lowered to the vicinity of the bottom dead center at the speed command value V0 during the period from time t0 to t3, for example. Then, the slider and the mold perform pressing and pressurization/regeneration of the mold pad at the speed command value V1 during the period from time t3 to t7. Then, the slider and the mold rise to the top dead center at the speed command value V0 during the period from time t7 to t10.

If the torque command is applied to the press, the torque command value will be the acceleration torque T0 during each period of time t0-t1 and t7-t8. In each period of time t2-t3 and t9-t10, the torque command value is the deceleration torque T2. During the time t4-t5, the torque command value is the pressure torque T3. During the time t5-t6, the torque command value is the regenerative torque T4. In each period of time t1-t2, t3-t4, t6-t7, and t8-t9, the torque command value is the friction torque T1.

These speed command values and torque command values can be pre-calculated or set during trial operation before formal operation. Therefore, the value obtained by adding the tolerance to these values can be set as the speed command limit value and the torque command limit value.

Fig. 4 is a diagram showing an example of a limit value table corresponding to Fig. 3. In the limit value table in Fig. 4, in addition to the speed command limit value and torque command limit value in each period, the rotation direction and position information indicating the state of the servo motor M are also stored. Since the status of the servo motor M in each period is also pre-stored in the limit value table, each period in the operation mode can be specified based on the position information of the servo motor M detected by the position detector EN. Furthermore, the rotation direction of the servo motor M is detected based on the position information detected by the position detector EN. For example, if the position information is output from the position detector EN every time the servo motor M rotates 120°, the rotation direction of the servo motor M can be easily detected.

Thereby, the speed command limit value and the torque command limit value to be compared can be easily selected, and the comparison process of the speed command value determination processing unit 23 and the torque command value determination processing unit 25 can be quickly executed.

<Main effects of this embodiment> According to this embodiment, when the input command value is within the range of the command limit value, the control processing unit 20 uses the input command value as the command value after comparison, and when the input command value is outside the range of the command limit value, it The command limit value is used as the command value after comparison.

According to this configuration, even when it is determined that the input command value (speed command value) is an abnormal value, the command value can be overwritten with the command limit value (speed command limit value) to be compared. By this, it is possible to suppress the situation that the input command value exceeds the command limit value due to the excessive command value caused by the operation failure in the upper device 100 or the load increase caused by interference, etc., so that the application with the servo motor M can be used The occurrence of malfunctions in the system is reduced.

Furthermore, according to the present embodiment, the torque command value determination processing unit 25 compares the torque command value generated by the speed control processing unit 24 with the torque command limit value to generate a compared torque command value. According to this configuration, even when an abnormal torque command value is generated by the calculation of the control processing unit 20, the torque command value can be overwritten to the torque command limit value, so that the control processing unit 20 can cause Misoperation in the application system is reduced.

Furthermore, according to the present embodiment, the command limit value to be compared is switched according to each period of the operation mode of the application system with the servo motor M. According to this configuration, the command limit value can be appropriately selected following the operation of the application system. Thereby, the tolerance of the command limit value relative to the input command value can be appropriately set.

Furthermore, according to this embodiment, the speed command limit value and the torque command limit value are switched based on the position information of the servo motor M detected by the position detector EN. According to this configuration, not only the speed command value, but also the torque command value generated by the control processing unit 20, the torque command limit value to be compared can be appropriately selected.

Furthermore, according to the present embodiment, when it is determined that at least one of the input command value (speed command value) and the torque command value is an abnormal value, an abnormality notification is output to the upper device 100. According to this configuration, the control processing unit 20 can notify that there is an abnormality in the speed command value or the torque command value.

(Embodiment 2) Next, the second embodiment will be described. In addition, in the following, descriptions of overlapping points with the above-mentioned embodiment are omitted in principle. In this embodiment, the position command value is input to the command value input circuit 10 from the host device 100 as the input command value. The input command value is input to the command value input circuit 10 through, for example, a network or pulse string input. The command value input circuit 10 outputs the input position command value to the control processing unit 20.

Fig. 5 is a block diagram showing an example of the configuration of the control processing unit in the second embodiment of the present invention. The control processing section 20 of FIG. 5 includes a position command value determination processing section 21, a position control processing section 22, a speed command value determination processing section 23, a speed control processing section 24, a torque command value determination processing section 25, and a torque control processing section 26, and limit value table 29.

The position command value judgment processing unit 21 is a functional block that judges whether the input position command value is a normal value. Specifically, the position command value determination processing unit 21 compares the input position command value with the position command limit value stored in the limit value table 29. The position command value determination processing unit 21 switches the speed command limit value to be compared in each period according to the operation mode.

When the position command value is within the range of the position command limit value selected as the comparison target, the position command value judgment processing unit 21 judges it as a normal value, and outputs the position command value as the compared position command value to the position control process部22.

In contrast, when the position command value is out of the range of the selected position command limit value, the position command value determination processing unit 21 determines that the position command value is an abnormal value, and uses the position command limit value as the compared position command value It is output to the position control processing unit 22. At this time, the position command value determination processing unit 21 outputs an abnormality notification indicating that the input position command value is an abnormal value to the host device 100. The abnormality notification may also include information about the period during which the abnormality occurred in the specific operation mode.

In the position command value determination processing unit 21, the position information of the servo motor M detected by the position detector EN is input. The position command value determination processing unit 21 can switch the position command limit value based on the position information of the servo motor M.

In addition, in the position command value determination processing unit 21, sensor information of the application system detected by the sensor AS is input. The position command value determination processing unit 21 can use the sensor information to identify each period in the operation mode and switch the position command limit value.

The position control processing unit 22 is a functional block that generates a speed command value based on the compared position command value. Specifically, the position control processing unit 22 calculates the speed corresponding to the compared position command value input from the position command value determination processing unit 21. Specifically, the position control processing unit 22 calculates the speed of the motor rotating shaft so that the position of the servo motor M at a specific time becomes the position specified by the compared position command value (position command value or position command limit value). The position control processing unit 22 outputs the calculated speed as a speed command value to the speed command value determination processing unit 23.

The position command value determination processing unit 21 sequentially inputs the position command value after comparison corresponding to each period of the operation mode to the position control processing unit 22. Then, the position control processing unit 22 sequentially outputs the corresponding speed command values to the speed command value determination processing unit 23 based on the input compared position command values.

In this embodiment, the speed command value judgment processing unit 23 compares the speed command value generated by the position control processing unit 22 with the speed command limit value stored in the limit value table 29, and determines whether the input speed command value is a normal value. The judgment. The other processing is the same as in the first embodiment.

＜Control method of servo motor＞ Next, the control method of the servo motor of this embodiment will be described. Fig. 6 is a diagram showing an example of a control method of a servo motor according to the second embodiment of the present invention. Fig. 6 shows the position command value, speed command value, torque command value, and sensor input 1, 2, and 3 timing diagrams as input command values, respectively. In the timing chart of position command value, speed command value, and torque command value, the position command limit value, speed command limit value, and torque command limit value in each period are also shown respectively. The timing chart of the position command value corresponds to the operation mode of this embodiment. The operation mode based on the position command value can be used, for example, to control the servo motor installed in NC (numerical control) machine tools.

First, during the time t0-t1, the position command value increases from 0 to P0. The speed command value during this period increases linearly from 0 to V0. The torque command value during this period is T0. During this period, the position limit value is PL0, the speed command limit value is VL0, and the torque command limit value is TL0.

During the period from t1 to t2, the position command value linearly increases from P0 to P1. The speed command value during this period is V0. The torque command value during this period is T1. During this period, the position command limit value is PL1, the speed command limit value is VL0, and the torque command limit value is TL1.

During the time t2-t3, the position command value increases from P1 to P2. However, the rate of increase in the second half of the period was slower than that in the first half. The speed command value during this period decreases linearly from V0 to 0. The torque command value during this period is T2. During this period, the position command limit value is PL2, the speed command limit value is VL0, and the torque command limit value is TL2. The torque command limit value TL2 is a value less than 0, and the torque command value is set to not less than the torque command limit value TL2.

During the time t3-t4, the position command value decreases from P2 to P1. However, the rate of decrease in the first half of the period was slower than that in the second half. The speed command value during this period decreases linearly from 0 to V1. The torque command value during this period is T2. The position command limit value during this period is PL3. The speed command limit value during this period is VL1. The torque command limit value during this period is TL2.

During the time t4-t5, the position command value linearly decreases from P1 to P0. The speed command value during this period is V1. The torque command value during this period is T3. During this period, the position command limit value is PL4, the speed command limit value is VL1, and the torque command limit value is TL3.

During the period from t5 to t6, the position command value decreases from P0 to 0. The speed command value during this period linearly increases from V1 to 0. The torque command value during this period is T0. During this period, the position command limit value is PL5, the speed command limit value is VL1, and the torque command limit value is TL0.

In the operation mode of the position command value as shown in Fig. 6, the servo motor of NC machine tool rotates from 0 to P2 and then returns to the original position. Specifically, the speed command value generated inside the control processing unit 20 based on the position command value causes the servo motor to rotate forward during the period from time t0 to t3. On the other hand, the speed command value in the period from time t3 to t6 causes the servo motor to rotate in the reverse direction.

The torque command value generated inside the control processing unit 20 according to the speed command value generates an acceleration torque during forward rotation during the period from time t0 to t1. The torque command value during the time t1-t2 produces a positive friction torque. The torque command value in the period from t2 to t3 produces the deceleration torque when rotating in the forward direction. The torque command value in the period from t3 to t4 produces the acceleration torque during reverse rotation. The torque command value in the period from t4 to t5 produces a reverse friction torque. The torque command value in the period from t5 to t6 produces the deceleration torque during reverse rotation.

The position, speed, and torque of the servo motor of the NC processing machine can be pre-calculated or set during the trial operation before the actual operation. Therefore, the value obtained by adding the tolerance to these values can be set as the position command limit value, the speed command limit value, and the torque command limit value.

Fig. 7 is a diagram showing an example of the limit value table corresponding to Fig. 6. In the limit value table in Fig. 7, in addition to the position command limit value, speed command limit value, and torque command limit value in each period, the status of sensor inputs 1, 2, and 3 (on, off) are also stored. ). The sensor AS detects the action of the application system including the servo motor, and switches the state of the sensor input 1, 2, and 3 (on, off) according to the detected action.

The input mode of the sensor AS is also pre-registered in the limit value table, so that the sensor information of the application system detected by the sensor AS can be used to switch the command limit value. Specifically, the control processing unit 20, for example, specifies the period in the operation mode based on the input modes of sensor inputs 1, 2, and 3, and selects the position command limit value, the speed command limit value, And torque command limit value.

Furthermore, regarding the position command value, not only the position command limit value stored in the limit value table, but also the position correction value generated based on the position command value of the previous sequence, etc. can be used as the position command limit. For example, in the period from time t1 to t2 in FIG. 6, near time t1, the difference between the position command value and the position command limit value becomes larger. In this case, the control processing unit 20 generates, for example, a position correction value obtained by adding a specific correction value to a position command value (P0, etc.) near time t1, and compares the position command value with the position correction value to generate the compared position Instruction value. Furthermore, this process may be continuously performed until the difference between the position command value and the position command limit value becomes within the range of the specific threshold value. According to this structure, the difference between the position command value and the position command limit value can be reduced, so that the servo motor and the application system can be operated more safely.

<Main effects of this embodiment> According to this embodiment, in addition to the effects of the above-mentioned embodiment, the following effects can be obtained. According to this embodiment, the control processing unit 20 generates a speed command value based on the input position command value, and generates a torque command value based on the speed command value.

According to this structure, even when the position command value is input, the occurrence of malfunctions in the application system with the servo motor M can be reduced. Furthermore, according to this structure, the position of the servo motor can be controlled, the occurrence of malfunctions can be suppressed, and precision processing using the application system can be performed.

Furthermore, according to this embodiment, the position command limit value, the speed command limit value, and the torque command limit value are switched based on the position information of the servo motor M detected by the position detector EN. According to this configuration, it is possible to appropriately select the position command limit value, the speed command limit value, and the torque command limit value to be compared with respect to the position command value, the speed command value, and the torque command value.

Furthermore, according to this embodiment, even when it is determined that the input command value (position command value) is an abnormal value, an abnormality notification can be output to the upper device 100. According to this configuration, it is possible to notify the higher-level device 100 that there is an abnormality in the position command value.

Furthermore, according to this embodiment, the position command limit value, the speed command limit value, and the torque command limit value are switched using the sensor information of the application system detected by the sensor AS. According to this structure, the period in the operation mode can be specified based on the input mode, and the position command limit value, the speed command limit value, and the torque command limit value can be appropriately selected.

In addition, the present invention includes various modifications and is not limited to the above-mentioned embodiment. In addition, a part of the configuration of a certain embodiment can be replaced with a configuration of another embodiment, and it is also possible to add a configuration of another embodiment to the configuration of a certain embodiment. For example, the control of the servo motor in the input mode of the sensor AS can also be applied to the first embodiment.

In addition, it is possible to add, delete, and replace other configurations to a part of the configuration of each embodiment. Furthermore, the various components or relative dimensions described in the drawings are simplified and idealized for easy understanding of the present invention, and may become more complicated shapes in installation.

1: Servo motor control device 10: Command value input circuit 11: AD conversion circuit 20: Control Processing Department 21: Position command value judgment processing unit 22: Position control processing unit 23: Speed command value judgment processing unit 24: Speed control processing section 25: Torque command value judgment processing unit 26: Torque control processing unit 29: Limit value table 30: Power conversion machine 40: converter 50: Smoothing circuit 60: converter 70: Gate driver 100: Upper device AS: Sensor EN: position detector t0: time t1: moment t2: moment t3: moment t4: moment t5: moment t6: moment t7: moment t8: moment t9: moment t10: moment M: Servo motor

Fig. 1 is a block diagram showing an example of the configuration of a servo motor control device according to the first embodiment of the invention. Fig. 2 is a block diagram showing an example of the configuration of the control processing unit in the first embodiment of the present invention. Fig. 3 is a diagram showing an example of the control method of the servo motor according to the first embodiment of the present invention. Fig. 4 is a diagram showing an example of a limit value table corresponding to Fig. 3. Fig. 5 is a block diagram showing an example of the configuration of the control processing unit in the second embodiment of the present invention. Fig. 6 is a diagram showing an example of a control method of a servo motor according to the second embodiment of the present invention. Fig. 7 is a diagram showing an example of a limit value table corresponding to Fig. 6.

20: Control Processing Department

23: Speed command value judgment processing unit

24: Speed control processing section

25: Torque command value judgment processing unit

26: Torque control processing unit

29: Limit value table

60: converter

70: Gate driver

100: Upper device

AS: Sensor

EN: position detector

M: Servo motor

Claims (8)

A servo motor control device that controls the servo motor based on the input command value input from the upper device, and includes: a control processing unit that compares the input command value with the command limit value to generate a compared command value , And based on the comparison command value to generate a current command value and a voltage command value; and a power converter, which supplies power to the servo motor based on the current command value and the voltage command value; and the control processing unit inputs the When the command value is within the range of the above-mentioned command limit value, the above-mentioned input command value is regarded as the above-mentioned comparative command value. When the above-mentioned input command value is outside the above-mentioned command limit value range, the above-mentioned command limit value is regarded as the above Command value after comparison; the control processing unit switches the command limit value that becomes the comparison target according to the period in the operation mode of the application system with the servo motor. For example, the servo motor control device of claim 1, wherein the input command value is a speed command value, and the control processing unit compares the speed command value with the speed command limit value to generate a compared speed command value based on the compared speed The torque command value is generated by the command value, the torque command value is compared with the torque command limit value to generate a compared torque command value, and the current command value and the voltage are generated based on the compared torque command value Instruction value. Such as the servo motor control device of claim 2, wherein the control processing unit switches the speed command limit value and the torque command limit value based on the position information of the servo motor detected by a position detector. For example, the servo motor control device of claim 2, wherein the control processing unit outputs an abnormality notification to the upper device when determining that at least one of the speed command value and the torque command value is an abnormal value. A servo motor control device that controls the servo motor based on the input command value input from the upper device, and includes: a control processing unit that compares the input command value with the command limit value to generate a compared command value , And based on the comparison command value to generate a current command value and a voltage command value; and a power converter, which supplies power to the servo motor based on the current command value and the voltage command value; and the control processing unit inputs the When the command value is within the range of the above-mentioned command limit value, the above-mentioned input command value is regarded as the above-mentioned comparative command value. When the above-mentioned input command value is outside the above-mentioned command limit value range, the above-mentioned command limit value is regarded as the above Command value after comparison; the input command value is a position command value, and the control processing unit compares the position command value with the position command limit value to generate a position command value after comparison, and generates a speed command based on the position command value after comparison Value, the above-mentioned speed command value is compared with the speed command limit value to generate the compared speed command value, and the torque command value is generated based on the above-mentioned compared speed command value, and the torque command value is compared with the torque command value. The torque command limit values are compared to generate a compared torque command value, and the current command value and the voltage command value are generated based on the compared torque command value. For example, the servo motor control device of claim 5, wherein the control processing unit uses the position information of the servo motor detected by a position detector to switch the position command limit value, the speed command limit value, and the torque command limit value. For example, the servo motor control device of claim 5, wherein the control processing unit outputs an abnormality notification to the above when determining that at least any one of the position command value, the speed command value, and the torque command value is an abnormal value Upper device. A servo motor control device that controls the servo motor based on the input command value input from the upper device, and includes: a control processing unit that compares the input command value with the command limit value to generate a compared command value , And based on the comparison command value to generate a current command value and a voltage command value; and a power converter, which supplies power to the servo motor based on the current command value and the voltage command value; and the control processing unit inputs the When the command value is within the range of the above-mentioned command limit value, the above-mentioned input command value is regarded as the above-mentioned comparative command value. When the above-mentioned input command value is outside the above-mentioned command limit value range, the above-mentioned command limit value is regarded as the above Command value after comparison; The control processing unit uses the sensor information of the application system with the servo motor detected by the sensor to switch the command limit value.

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