JP6885436B2 - Servo amplifier and servo system - Google Patents

Description

The present invention relates to a servo amplifier and a servo system.

Conventionally, a motor control device including a load torque observer that estimates the load torque received by a motor based on a torque command and a motor speed is known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2012-130214

However, in the conventional technique, although the estimated load torque is used for motor control for the purpose of suppressing disturbance, it is not possible to monitor the information on the estimated load torque from the outside.

Therefore, the present disclosure provides a servo amplifier and a servo system capable of monitoring information on the estimated load torque from the outside.

This disclosure is
A speed control unit that generates a torque command for the motor based on the speed command for the motor that moves the moving unit.
A torque control unit that controls the torque of the motor based on the torque command,
A load torque estimation unit that estimates the load torque received by the motor based on the speed command input and the load torque estimation unit.
It is provided with an output unit that outputs information on the load torque estimated by the load torque estimation unit to the outside of the servo amplifier .
The load torque estimation unit provides a servo amplifier that estimates the load torque by estimating the disturbance torque received by the motor using the speed command and the torque command or the torque detection value of the motor. ..

In addition, this disclosure is
A servo amplifier and an external device provided outside the servo amplifier are provided.
The servo amplifier
A speed control unit that generates a torque command for the motor based on the speed command for the motor that moves the moving unit.
A torque control unit that controls the torque of the motor based on the torque command,
A load torque estimation unit that estimates the load torque received by the motor based on the speed command input and the load torque estimation unit.
Bei example an output section for outputting the information on the load torque estimated by the load torque estimating unit to the external device,
The load torque estimation unit provides a servo system that estimates the load torque by estimating the disturbance torque received by the motor using the speed command and the torque command or the torque detection value of the motor. ..

According to the technique of the present disclosure, it is possible to provide a servo amplifier and a servo system capable of externally monitoring information on an estimated load torque.

It is a figure which illustrates the structure of the servo system in one comparative form. It is a figure which illustrates the structure of the servo system in 1st Embodiment. It is a figure which illustrates the structure of the servo system in 2nd Embodiment. It is a figure which exemplifies each waveform when the gravitational torque is included in the estimated load torque. It is a figure which exemplifies each waveform when the gravitational torque is not included in the estimated load torque. It is a figure which illustrates the structure of the servo system in 3rd Embodiment. It is a figure which illustrates each waveform when the feedback speed is used for the estimation of a load torque. It is a figure which exemplifies each waveform when the command speed is used for the estimation of a load torque. It is a figure which illustrates each waveform at the time of peak-holding the estimated value of a load torque. It is a figure which shows the normal state of crimping between a terminal and an electric wire. It is a figure which shows the abnormal state of crimping between a terminal and an electric wire. It is a figure which exemplifies each waveform at the time of time integration of the estimated value of a load torque.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. First, in order to compare with the embodiment of the present disclosure, the configuration of the servo system in one comparative embodiment will be described.

FIG. 1 is a diagram illustrating the configuration of a servo system in one comparative form. The servo system 100 shown in FIG. 1 is a motor system that controls a motor 9 for moving a movable portion (not shown). The servo system 100 includes a speed control unit 1, an adder 2, a torque control unit 3, a speed detection unit 4, a load torque estimation unit 5, a control filter 8, a motor 9, and a position detector 10.

The torque control unit 3 controls the torque of the motor 9 based on the torque command Tr. The position detector 10 detects the position (rotational position θ) of the motor 9. The position detector is also referred to as PG. The speed detection unit 4 detects the speed (angular velocity ω) of the motor 9 based on the temporal change of the rotation position θ detected by the position detector 10. The speed control unit 1 generates a feedback torque command Tb that causes the angular velocity ω detected by the speed detection unit 4 to follow the speed command ωr supplied from the control block in the previous stage (not shown).

Further, the servo system 100 includes a load torque estimation unit 5 in order to estimate the load torque TL received by the motor 9. The load torque estimation unit 5 estimates the load torque TL based on the torque command Tr and the angular velocity ω detected by the speed detection unit 4.

When the torque generated by the motor 9 is T, the moment of inertia (inertia value) of the motor 9 is J, and the angular acceleration of the motor 9 is dω / dt, the load torque TL is generated by the gravity acting on the moving part moved by the motor 9. When torque (gravity torque) is included
TL = TJ × dω / dt ・ ・ ・ Equation 1
The relational expression is established. Therefore, the load torque estimation unit 5 estimates the load torque TL by subtracting the torque (J × dω / dt) calculated by the torque calculation unit 6 from the torque command Tr by the subtractor 7.

The control filter 8 generates a compensated load torque TLc by applying a filter process to the load torque TL (estimated load torque TLe) estimated by the load torque estimation unit 5. The adder 2 generates a torque command Tr by adding the feedback torque command Tb generated by the speed control unit 1 and the compensating load torque TLc generated by the control filter 8.

However, in the servo system 100 shown in FIG. 1, although the load torque TL estimated by the load torque estimation unit 5 is used for motor control for the purpose of suppressing disturbance, information on the estimated load torque TLe is monitored from the outside. It is not possible.

Therefore, the servo amplifier and the servo system according to the embodiment of the present disclosure have a configuration in which information on the estimated load torque can be monitored from the outside. Next, the configuration of the servo amplifier and the servo system according to the embodiment of the present disclosure will be described.

FIG. 2 is a diagram illustrating the configuration of the servo system according to the first embodiment. The servo system 120 shown in FIG. 2 is a motor drive control system that drives and controls a motor 19 that moves a movable portion 40 by an arm 41 in a moving direction having a vertical component. The servo system 120, for example, drives and controls the motor 19 to control the position of the movable portion 40 to a desired position. The servo system 120 includes a servo amplifier 111 and an external device 122.

The external device 122 is a device provided outside the servo amplifier 121, and has a load torque TL monitoring function. The external device 122 is connected to the servo amplifier 121 by analog voltage, wired communication, or wireless communication. The external device 122 is, for example, a control device such as a programmable logic controller.

The servo amplifier 111 is a motor drive device that drives a motor 19 that moves a movable portion 40 by an arm 41 in a moving direction having a vertical component. For example, the servo amplifier 111 drives the motor 19 to position the movable portion 40 at a desired position. To control. The servo amplifier 111 includes, for example, a speed control unit 11, an adder 12, a torque control unit 13, a speed detection unit 14, a load torque estimation unit 15, a control filter 18, and an output unit 23 as main configurations.

The torque control unit 13 controls the torque of the motor 19 based on the torque command Tr. The position detector 20 detects the position (rotational position θ) of the motor 19. The speed detection unit 14 detects the speed (angular velocity ω) of the motor 19 based on the temporal change of the position detected by the position detector 20. The speed control unit 11 generates a feedback torque command Tb that causes the angular velocity ω detected by the speed detection unit 14 to follow the speed command ωr supplied from the control block in the previous stage (not shown). For example, the speed control unit 11 performs PI control (proportional control and integral control) so that the deviation between the angular velocity ω detected by the speed detection unit 14 and the speed command ωr supplied from the control block in the previous stage (not shown) becomes zero. ) Is performed to generate the feedback torque command Tb.

The load torque estimation unit 15 estimates the load torque TL (load torque TL applied to the motor 9) received by the motor 9 based on the torque command Tr or the torque detection value Tde and the angular velocity ω detected by the speed detection unit 14. To do. The load torque estimation unit 5 is, for example, a load torque observer that estimates the load torque TL. The torque detection value Tde used for estimating the load torque TL represents the torque value of the motor 19 detected by the torque detection unit 21. That is, the torque command Tr may be used or the torque detection value Tde may be used for estimating the load torque TL. For example, when the torque detection unit 21 is not provided in the servo amplifier 111, the torque command Tr is used for estimating the load torque TL. Hereinafter, the load torque TL estimated by the load torque estimation unit 15 is also referred to as "estimated load torque TLe".

In one comparative mode shown in FIG. 1, the load torque TL is estimated by including the gravity torque in the load torque TL. The first embodiment shown in FIG. 2 shows a case where the load torque TL is estimated without including the gravity torque in the load torque TL.

The gravitational torque represents the torque required to cancel the gravitational component acting on the movable portion 40 that is moved by the arm 41 in the moving direction having a vertical component. The motor 19 is a movable portion 40 coupled to the arm 41 by moving an arm 41 connected to the rotation output shaft of the motor 19 via a gear or the like in a direction having a vertical component (for example, a vertical direction). Is moved in the direction of movement having a vertical component. The movable portion 40 is, for example, a press operation portion that presses the work W fixed on the mounting table from above. The arm 41 uses, for example, a ball screw to move the movable portion 40 in the moving direction having a vertical component. The movable portion 40 may perform a machining operation such as a pressing operation, a drilling operation, or a shearing operation.

For example, consider the case where the arm 41 is a ball screw that moves the movable portion 40 in the extending direction thereof. The gravity acting on the center of gravity of the movable part 40 is Fg, the gravity component of the gravity Fg in the extending direction of the arm 41 (moving direction of the moving part 40) is Fg', the gravity torque is Tg, and the vertical direction and the extending direction of the arm 41. Let α be the angle of, and let BP be the pitch (lead) of the ball screw. When the angle α is zero, it means that the movable portion 40 moves only in the vertical direction. At this time, the gravitational component Fg'and the gravitational torque Tg are, respectively.
Fg'= Fg × cosα ・ ・ ・ Equation 2
Tg = (BP / 2π) × Fg'・ ・ ・ Equation 3
The relational expression is established.

Further, the torque generated by the motor 19 is T, the moment of inertia (moment of inertia) of the moving part of the load machine directly or indirectly connected to the motor 19 and the motor 19 is J, the angular acceleration of the motor 19 is dω / dt, and the motor 19 Let Td be the disturbance torque received by the disturbance torque, and let Tg be the gravity torque included in the disturbance torque Td. At this time, if the load torque TL does not include the gravity torque Tg,
TL = Td-Tg = TJ × dω / dt-Tg ・ ・ ・ Equation 4
The relational expression is established. By removing the gravitational torque Tg from the load torque TL to be estimated, the estimation accuracy of the load torque TL is improved.

When the load torque TL is estimated using the equation 4, the load torque estimation unit 15 includes, for example, a disturbance torque estimation unit 28 and a subtractor 30.

The disturbance torque estimation unit 28 estimates the disturbance torque Td (disturbance torque Td applied to the motor 19) received by the motor 19 based on the torque command Tr or the torque detection value Tde and the angular velocity ω detected by the speed detection unit 14. To do. The disturbance torque estimation unit 28 is, for example, a disturbance torque observer that estimates the disturbance torque Td. Hereinafter, the disturbance torque Td estimated by the disturbance torque estimation unit 28 is also referred to as "estimated disturbance torque Tdie".

The disturbance torque estimation unit 28 has the same configuration as the load torque estimation unit 5 shown in FIG. 1, for example. In this case, the disturbance torque estimation unit 28 subtracts the torque (J × dω / dt) calculated by the torque calculation unit 6 from the torque command Tr or the torque detection value Tde by the subtractor 7 in the same manner as described above. , Estimate the disturbance torque Td. The disturbance torque estimation unit 28 is not limited to this configuration, and may have any known configuration.

As shown in Equation 4, the load torque TL can be estimated by subtracting the gravitational torque Tg from the disturbance torque Td. Therefore, the load torque estimation unit 15 estimates the load torque TL by subtracting the gravity torque Tg from the disturbance torque Td (estimated disturbance torque Tdie) estimated by the disturbance torque estimation unit 28 by the subtractor 30. That is, by compensating for the gravitational torque Tg, a highly accurate estimated load torque TLe can be obtained.

For example, the load torque estimation unit 15 estimates the load torque TL by subtracting a constant gravitational torque Tg from the disturbance torque Td (estimated disturbance torque Tdie) estimated by the disturbance torque estimation unit 28. When the angle α is fixed and the movable portion 40 moves in a straight line in the vertical direction, the gravitational torque Tg becomes a constant value according to Equation 3. Therefore, the constant gravitational torque Tg can be set (stored) in advance inside the servo amplifier 111.

Alternatively, the load torque estimation unit 15 estimates the load torque TL by reducing the gravity torque Tg supplied from the outside of the servo amplifier from the disturbance torque Td (estimated disturbance torque Tdie) estimated by the disturbance torque estimation unit 28. You may. The mass of the movable portion 40 may change or the angle α may change due to a change in the operating state or the setup. When the external device 122 has such variable information, the value of the gravitational torque Tg every moment is calculated by the external device 122, and the calculated value of the gravitational torque Tg every moment is calculated from the external device 122 by communication with the servo amplifier. It is supplied to the load torque estimation unit 15 of 111. In this way, even if the gravitational torque Tg changes, the servo amplifier 111 can obtain the gravitational torque Tg from the external device 122 and use it for estimating the load torque TL.

The control filter 18 generates a compensating load torque TLc by filtering the estimated load torque TLe. The adder 12 generates a torque command Tr by adding the feedback torque command Tb generated by the speed control unit 11 and the compensating load torque TLc generated by the control filter 18.

The servo amplifier 111 includes an output unit 23 that outputs information (monitoring information) regarding the estimated load torque TLe to the outside of the servo amplifier 111. As a result, information on the estimated load torque TLe can be output to the outside of the servo amplifier 111 (for example, the external device 122). Therefore, not only can the estimated load torque TLe be reflected in the calculation of the torque command Tr and used for servo control of the motor 19 for the purpose of suppressing disturbance, but also information on the estimated load torque TLe can be used outside the servo amplifier 111 (for example, an external device). It can be monitored from 122).

For example, when an abnormality (for example, aged deterioration, contact with a foreign substance, etc.) occurs in the movable portion 40 whose position or the like is controlled by the motor 19, or the motor 19 itself, the estimated load torque TLe changes. Therefore, by monitoring the information regarding the estimated load torque TLe output from the output unit 23 outside the servo amplifier 111, it is possible to detect an abnormality occurring in the movable unit 40 or the motor 19 outside the servo amplifier 111. Become.

Examples of the information regarding the estimated load torque TLe include the value of the estimated load torque TLe and the result of performing an abnormality determination based on the estimated load torque TLe inside the servo amplifier 111.

The output unit 23 may output the information regarding the estimated load torque TLe to the outside by analog output, or may output it to the outside by wired communication or wireless communication.

For example, the output unit 23 converts the value of the estimated load torque TLe into an analog voltage value and outputs it to the outside. As a result, the external device 122 of the servo amplifier 111 can detect the value of the estimated load torque TLe according to the analog voltage value output from the output unit 23. Similarly, when the output unit 23 communicates and outputs the value of the estimated load torque TLe on a predetermined carrier wave, the external device 122 of the servo amplifier 111 receives the carrier wave output from the output unit 23 to receive the estimated load torque TLe. The value of can be detected. For example, the output unit 23 peak-holds the estimated value of the load torque and transmits the peak hold value of the estimated value to the outside of the servo amplifier.

Similarly, the output unit 23 may convert the information indicating the result (normal or abnormal) of the abnormality determination based on the estimated load torque TLe inside the servo amplifier 111 into an analog voltage value and output it externally. , Communication output may be performed on a predetermined carrier wave. As a result, the external device 122 of the servo amplifier 111 can acquire the result of the abnormality determination by the servo amplifier 111 by detecting the analog voltage or the carrier wave output from the output unit 23.

By the way, as described above, the moment of inertia (inertia value J) of the motor 19 and the moving part of the load machine connected to the motor 19 is used for estimating the load torque TL. When the inertia value used for estimating the load torque TL is also used as the inertia value used for determining the servo control parameter (for example, the control gain A of the proportional control performed by the speed control unit 11), the load torque TL The inertial value used for estimation is not always set correctly. This is because an inertial value suitable for improving the controllability of servo control is not always suitable for improving the estimation accuracy of the load torque TL. In addition, the moment of inertia ratio used to determine the servo control parameters should be set to an approximate value such as 1, 5 or 10 times, as long as there is no problem in servo control even if there is some error. It may be finely adjusted with the tuning gain. In such a case, it is difficult to accurately estimate the load torque TL.

In this regard, the servo amplifier 111 shown in FIG. 2 has a first inertial value setting unit 24 for setting a first inertial value Jc for controlling the motor 19 and a second inertial value Je for estimating the load torque TL. A second inertial value setting unit 26 for setting is provided. That is, a function is provided in which the inertia value can be set independently for estimating the load torque TL and for controlling the motor 19. By providing the function that can set the inertial value independently in this way, it becomes possible to set a more appropriate inertial value for estimating the load torque TL, and the estimation accuracy of the load torque TL is improved. Further, since it is possible to set appropriate inertial values for the estimation of the load torque TL and the control of the motor 19, it is possible to improve the control accuracy of the servo control and the estimation accuracy of the load torque TL. It is possible to achieve both.

For example, the first inertia value setting unit 24 automatically tunes the control gain A based on the input first inertia value Jc, and sets the control gain of the proportional control performed by the speed control unit 11 after the auto tuning. The control gain A is set. On the other hand, the second inertia value setting unit 26 uses the inertia value J used for estimating the load torque TL in the load torque estimation unit 15 (for example, the inertia value J used for calculating the above-mentioned (J × dω / dt)). ), The input second inertia value Je is set.

The first inertial value Jc or the second inertial value Je may be an estimated value obtained by the inertial value estimation calculation function provided in the servo amplifier 111, or information input from the user or the external device 122 of the servo amplifier 111. It may be a value determined based on.

Further, the servo amplifier 111 shown in FIG. 2 has a first filter value setting unit 25 for setting a first filter value Kc for controlling the motor 19 and a second filter value setting unit 25 for outputting monitoring information regarding the estimated load torque TLe. A second filter value setting unit 27 for setting the filter value Ko is provided. That is, there is a function that allows the filter value to be set independently for the output of monitoring information and for the control of the motor 19. By providing the function that can set the filter value independently in this way, not only the filter value suitable for the servo control of the motor 19 can be set, but also the external device 122 of the servo amplifier 111 is suitable for monitoring the monitoring information. You can set the filter value.

The servo amplifier 111 includes, for example, a control filter 18 for controlling the motor 19 and an output filter 22 for outputting monitoring information. The first filter value setting unit 25 sets the input first filter value Kc to the control filter 18, and the second filter value setting unit 27 sets the second filter input to the output filter 22. Set the value Ko. For example, the first filter value Kc is the response time constant of the control filter 18, and the second filter value Ko is the response time constant of the output filter 22, but the filter is not limited to this and is performed by each filter. It is set to a value suitable for processing. The control filter 18 generates a compensated load torque TLc by applying a filter process using the first filter value Kc to the estimated load torque TLe. The output filter 22 generates an estimated load torque TLe suitable for external monitoring by applying a filter process using the second filter value Ko to the estimated load torque TLe.

The output filter 22 may be a low-pass filter, a band-pass filter, or a high-pass filter. Filter characteristics suitable for external monitoring are set.

FIG. 3 is a diagram illustrating the configuration of the servo system in the second embodiment. The servo system 140 shown in FIG. 3 includes a servo amplifier 121 and an external device 122. The description of the same configuration and effect as in the above-described embodiment will be omitted or simplified by referring to the above-mentioned description.

In the second embodiment, the configuration of the load torque estimation unit 15 is different from that in the first embodiment. In the second embodiment, the load torque estimation unit 15 reduces the gravity torque Tg from the disturbance torque Td (estimated disturbance torque Tdie) estimated by the disturbance torque estimation unit 28 by the high frequency passing filter 32, thereby reducing the load torque TL. To estimate. The high frequency passing filter 32 outputs the estimated load torque TLe in which the component of the gravity torque Tg is attenuated by inputting the disturbance torque Td and attenuating the gravity torque Tg included in the input disturbance torque Td. When the frequency component of the gravitational torque Tg is a DC component (for example, when the gravitational torque Tg is a constant value as described above), the disturbance torque Td is filtered by the high frequency passing filter 32 to obtain the gravitational torque Tg. An estimated load torque TLe with the corresponding DC component attenuated can be obtained.

FIG. 4 is a diagram illustrating each waveform when the estimated load torque includes the gravitational torque, and shows a case where the load torque estimation unit 5 in one comparative form estimates the load torque TL. FIG. 5 is a diagram illustrating each waveform when the estimated load torque does not include the gravitational torque, and shows a case where the load torque estimation unit 15 in the first or second embodiment estimates the load torque TL. In FIGS. 4 and 5, "speed" represents the pressing speed (or angular velocity ω) when the movable portion 40 presses the metal work W, and "load torque" is the estimated load calculated inside the servo amplifier. Represents torque TLe.

In the case of FIG. 4, since the metal is pressed in the descending motion, a load torque is applied near the lower fulcrum, but since the gravitational torque Tg is included in the estimated load torque TLe by about 20%, the load torque (in this case). , Press torque) cannot be monitored accurately. On the other hand, in the case of FIG. 5, since the gravitational torque Tg is not included in the estimated load torque TLe, the estimated load torque TLe can be expressed as an amount that changes to the zero reference, and the press torque can be monitored accurately and intuitively. Can be done.

FIG. 6 is a diagram illustrating the configuration of the servo system according to the third embodiment. The servo system 160 shown in FIG. 6 includes a servo amplifier 131 and an external device 122. The description of the same configuration and effect as in the above-described embodiment will be omitted or simplified by referring to the above-mentioned description.

In the third embodiment, the load torque estimation unit 15 estimates the load torque TL based on the speed command ωr of the motor 19, and the speed detection value of the motor 19 (angular velocity ω detected by the speed detection unit 14). It is different from the above-described embodiment in which the load torque TL is estimated based on. The load torque estimation unit 15 estimates the load torque TL by the disturbance torque estimation unit 28 estimating the disturbance torque Td based on the speed command ωr.

For example, in the calculation of the load torque TL shown in FIG. 1, the angular velocity ω obtained by differentiating the rotation position θ detected by the position detector 20 by the speed detection unit 14 is used. However, since the rotation position θ detected by the position detector 20 contains a noise component, when this is differentiated, a large noise component tends to appear at the angular velocity ω. In particular, if the inertia value is large, the noise component may become unsuitable for monitoring. When the angular velocity ω obtained by the velocity detection unit 14 is further differentiated to obtain the angular acceleration dω / dt, the noise component may be further increased.

On the other hand, the load torque estimation unit 15 shown in FIG. 6 calculates the load torque TL using the angular acceleration dω / dt obtained by differentiating the speed (command speed) commanded by the speed command ωr. Since the speed (command speed) commanded by the speed command ωr is an internal value of the servo amplifier 131, the noise component is relatively small. Therefore, by using the speed (command speed) commanded by the speed command ωr, it may be possible to perform highly accurate monitoring with less noise.

As shown in FIG. 3, the load torque estimation unit 15 shown in FIG. 6 may estimate the load torque TL by using the high frequency passing filter 32.

FIG. 7 is a diagram illustrating each waveform when the feedback speed (angular velocity ω detected by the speed detection unit 14) is used for estimating the load torque. FIG. 8 is a diagram illustrating each waveform when a command speed (speed commanded by the speed command ωr) is used for estimating the load torque.

In the case of FIG. 7, since the differential of the feedback speed is used, the estimated load torque TL can be calculated instantly according to the change of the angular velocity ω when the load torque TL is applied due to the actual load. On the other hand, as shown in FIG. 8, when the differential of the command speed is used, the change in the angular velocity ω when the load torque TL is applied due to the actual load is not reflected in the estimation of the load torque TL. Therefore, as the torque command Tr rises as a result of the speed control, the estimated load torque TLe rises. That is, the response speed of the estimated load torque TLe is determined by the response speed of the speed control. However, the response of the speed control is usually about 30 to 100 Hz (about 5 to 1 ms when converted to the time constant), and is sufficiently fast, so that there is no problem in practical use.

By the way, in the waveform of the estimated load torque TLe illustrated in FIG. 5, sampling of about 1 ms is required to detect the peak value from the estimated load torque TLe output from the output unit 23 by the external device 122. When this peak detection is performed by bus communication, it is required that the bus communication be performed in about 1 ms. Therefore, high accuracy is required for peak detection on the external device 122 side, and high-precision peak detection is not easy.

Therefore, as shown in FIG. 9, the output unit 23 in each embodiment peak-holds the estimated value of the load torque TL, resets the peak hold value of the estimated value each time it is transmitted to the outside of the servo amplifier, and loads the load. The estimated value of torque TL may be peak-held again. The output unit 23 peak-holds the estimated load torque TLe during the period between transmission and reception by bus communication, transmits the latest peak hold value to the external device 122 at the transmission timing, and resets the internal peak hold value. As a result, for example, even when the bus communication is about 5 ms, the external device 122 can detect the peak without any omission. Therefore, even in a system in which data update is relatively slow, the external device 122 performs abnormality determination of the motor 19 and the like with relatively high accuracy based on the estimated load torque TLe without missing the peak value of the estimated load torque TLe. it can.

As an example where it is required to detect the peak torque on the external device 122 side,
-When the information of one cycle of the machine is only on the external device 122 side and it is unclear which section of the peak should be detected by the servo amplifier side-Which of the multiple peaks in one cycle is judged as abnormal There are cases where the condition for determining whether to use is only on the external device 122 side.

Alternatively, the output unit 23 in each embodiment may time-integrate the estimated value of the load torque TL and transmit the time-integrated value of the estimated value to the outside of the servo amplifier. As a result, even if the difference between the normal and abnormal peak values of the estimated load torque TLe is relatively small, the external device 122 has an abnormality such as the motor 19 based on the time integral value supplied from the output unit 23. Judgment can be performed with relatively high accuracy.

FIG. 12 is a diagram illustrating each waveform when the estimated value of the load torque is time-integrated. When the servo system of the present embodiment is applied to the press machine, the waveforms of the speed and the load torque are abnormal as normal. The result of comparison with time is shown. In FIG. 12, the “speed” represents the press speed (or angular velocity ω) when the movable portion 40 presses the metal receptacle terminal, and the “load torque” is the estimated load torque TLe calculated inside the servo amplifier. Represents. In FIG. 12, “normal” indicates a case where the crimping between the receptacle terminal 60 and the electric wire 51 is normal (see FIG. 10), and “abnormal” indicates a case where the crimping between the receptacle terminal 60 and the electric wire 51 is abnormal. It is shown (see FIG. 11).

In FIG. 10, the movable portion 40 of the press machine presses the root portion 61 of the receptacle terminal 60 together with the conducting wire 53 exposed by peeling off the coating 52 at the tip portion of the electric wire 51, and the conducting wire 53 and the root portion 61 are crimped. Indicates the normal state. In FIG. 11, the movable portion 40 of the press machine presses the root portion 61 of the receptacle terminal 60 with the coating 52 at the tip of the electric wire 51 covering the conducting wire 53 without peeling off, and the electric wire 51 and the root portion 61 are shown. Indicates an abnormal state in which and is crimped.

In the abnormal waveform illustrated in FIG. 12, since the electric wire 51 is crimped with the coating 52 covered, the estimated load torque TLe becomes larger on the negative side faster than the normal waveform due to the presence of foreign matter (coating 52). It has become. In the output unit 23, for example, during a period in which the angular velocity ω is lower than the predetermined velocity threshold value ωa (for example, −200 rpm) and the estimated load torque TLe is lower than the predetermined torque threshold value TLa (for example, −20%). The estimated load torque TLe is time-integrated. When time-integrating under this condition, the output unit 23 will time-integrate in the period t1-t3 when it is abnormal, and time-integrate in the period t2-t3 when it is normal. The time integral value (corresponding to the area of the hatched portion in FIG. 12) can clearly discriminate between the abnormal state and the normal state. As described above, even in the case where it is difficult to discriminate by the peak value of the estimated load torque TLe, it becomes easy to determine the abnormality of the motor 19 or the like by comparing with the time integral value.

As described above, according to the above-described embodiment, since the monitoring information regarding the estimated load torque TL is output externally, it is possible to externally monitor the information regarding the estimated load torque.

In the above-described embodiment, the functions of each part such as the estimated torque estimation part included in the servo amplifier are obtained by operating a processor (for example, a CPU (Central Processing Unit)) by a program readable and stored in a memory. It will be realized.

Although the servo amplifier and the servo system have been described above by the embodiment, the present invention is not limited to the above embodiment. Various modifications and improvements, such as combinations and substitutions with some or all of the other embodiments, are possible within the scope of the present invention.

15 Load torque estimation unit 18 Control filter 22 Output filter 23 Output unit 24 First inertia value setting unit 25 First filter value setting unit 26 Second inertia value setting unit 27 Second filter value setting unit 28 Disturbance torque estimation Part 29 Friction torque estimation part 30 Subtractor 32 High frequency pass filter 40 Moving part 100, 120, 140, 160 Servo system 111, 121, 131 Servo amplifier 122 External device

Claims (19)

A speed control unit that generates a torque command for the motor based on the speed command for the motor that moves the moving unit.
A torque control unit that controls the torque of the motor based on the torque command,
A load torque estimation unit that estimates the load torque received by the motor based on the speed command input and the load torque estimation unit.
It is provided with an output unit that outputs information on the load torque estimated by the load torque estimation unit to the outside of the servo amplifier .
The load torque estimation unit is a servo amplifier that estimates the load torque by estimating the disturbance torque received by the motor by using the speed command and the torque command or the torque detection value of the motor. The servo amplifier according to claim 1 , wherein the load torque estimation unit estimates the load torque by reducing the gravity torque generated by the gravity acting on the movable portion from the disturbance torque. The servo amplifier according to claim 2 , wherein the load torque estimation unit estimates the load torque by subtracting a constant gravitational torque from the disturbance torque. The servo amplifier according to claim 2 , wherein the load torque estimation unit estimates the load torque by reducing the gravity torque supplied from the outside of the servo amplifier from the disturbance torque. The servo amplifier according to claim 2 , wherein the load torque estimation unit estimates the load torque by reducing the gravity torque from the disturbance torque by a high-pass filter. The servo amplifier according to any one of claims 1 to 5 , wherein the output unit peak-holds the estimated value of the load torque and transmits the peak hold value of the estimated value to the outside of the servo amplifier. The servo amplifier according to any one of claims 1 to 5 , wherein the output unit time-integrates the estimated value of the load torque and transmits the time-integrated value of the estimated value to the outside of the servo amplifier. A speed control unit that generates a torque command for the motor based on the speed command for the motor that moves the moving unit.
A torque control unit that controls the torque of the motor based on the torque command,
A load torque estimation unit that estimates the load torque received by the motor based on the speed command input and the load torque estimation unit.
It is provided with an output unit that outputs information on the load torque estimated by the load torque estimation unit to the outside of the servo amplifier .
The output unit is a servo amplifier that peak-holds the estimated value of the load torque and transmits the peak hold value of the estimated value to the outside of the servo amplifier. The servo amplifier according to claim 6 or 8 , wherein the output unit resets each time the peak hold value is transmitted to the outside of the servo amplifier, and peak-holds the estimated value of the load torque again. A speed control unit that generates a torque command for the motor based on the speed command for the motor that moves the moving unit.
A torque control unit that controls the torque of the motor based on the torque command,
A load torque estimation unit that estimates the load torque received by the motor based on the speed command input and the load torque estimation unit.
It is provided with an output unit that outputs information on the load torque estimated by the load torque estimation unit to the outside of the servo amplifier .
The output unit is a servo amplifier that time-integrates the estimated value of the load torque and transmits the time-integrated value of the estimated value to the outside of the servo amplifier. The servo amplifier according to any one of claims 1 to 10 , wherein the load torque estimation unit estimates the load torque during a pressing operation of the movable part. The servo amplifier according to any one of claims 1 to 11 , wherein the motor moves the movable portion in a moving direction having a vertical component. A servo amplifier and an external device provided outside the servo amplifier are provided.
The servo amplifier
A speed control unit that generates a torque command for the motor based on the speed command for the motor that moves the moving unit.
A torque control unit that controls the torque of the motor based on the torque command,
A load torque estimation unit that estimates the load torque received by the motor based on the speed command input and the load torque estimation unit.
Bei example an output section for outputting the information on the load torque estimated by the load torque estimating unit to the external device,
The load torque estimation unit is a servo system that estimates the load torque by estimating the disturbance torque received by the motor by using the speed command and the torque command or the torque detection value of the motor. A servo amplifier and an external device provided outside the servo amplifier are provided.
The servo amplifier
A speed control unit that generates a torque command for the motor based on the speed command for the motor that moves the moving unit.
A torque control unit that controls the torque of the motor based on the torque command,
A load torque estimation unit that estimates the load torque received by the motor based on the speed command input and the load torque estimation unit.
Bei example an output section for outputting the information on the load torque estimated by the load torque estimating unit to the external device,
The output unit is a servo system that peak-holds the estimated value of the load torque and transmits the peak hold value of the estimated value to the external device. A servo amplifier and an external device provided outside the servo amplifier are provided.
The servo amplifier
A speed control unit that generates a torque command for the motor based on the speed command for the motor that moves the moving unit.
A torque control unit that controls the torque of the motor based on the torque command,
A load torque estimation unit that estimates the load torque received by the motor based on the speed command input and the load torque estimation unit.
Bei example an output section for outputting the information on the load torque estimated by the load torque estimating unit to the external device,
The output unit is a servo system that integrates the estimated value of the load torque over time and transmits the time-integrated value of the estimated value to the external device. A first inertial value setting unit that sets a first inertial value for controlling the motor, and a first inertial value setting unit.
The servo amplifier according to any one of claims 1 to 12 , further comprising a second inertial value setting unit for setting a second inertial value for estimating the load torque. A first filter value setting unit that sets a first filter value for controlling the motor, and a first filter value setting unit.
The servo amplifier according to any one of claims 1 to 12 , 16 comprising a second filter value setting unit for setting a second filter value for output of the information. The servo amplifier
A first inertial value setting unit that sets a first inertial value for controlling the motor, and a first inertial value setting unit.
The servo system according to any one of claims 13 to 15, further comprising a second inertial value setting unit that sets a second inertial value for estimating the load torque. The servo amplifier
A first filter value setting unit that sets a first filter value for controlling the motor, and a first filter value setting unit.
The servo system according to any one of claims 13 to 15, 18 comprising a second filter value setting unit for setting a second filter value for output of the information.

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