Motor control device
Patent Information
- Application Number
- PCT/JP2024/008338
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-03-05
- Publication Date
- 2025-10-02
AI Technical Summary
Existing motor control devices face challenges in setting an appropriate initial gain for automatic filter characteristic adjustment, which can lead to oscillation or insufficient gain, making it difficult to determine resonance.
A motor control device with a speed control loop, signal input unit, input/output response calculation unit, condition setting unit, condition comparison unit, and gain setting unit to determine and adjust the initial gain based on specific criteria to prevent oscillation and ensure sufficient gain.
Enables setting of an appropriate initial gain before automatic adjustment, preventing oscillation and ensuring accurate resonance detection during automatic characteristic adjustment.
Smart Images
Figure JP2024008338_02102025_PF_FP_ABST
Abstract
Description
Motor control device
[0001] The present invention relates to a motor control device.
[0002] Conventionally, in motor control devices, filter adjustment is performed by changing various parameters based on measurement results of frequency response, etc. Techniques for automatically adjusting the speed control gain, which is one of the parameters, are disclosed in, for example, Patent Document 1 and Patent Document 2.
[0003] JP 2016-092935 A JP 2017-192212 A
[0004] Frequency response varies depending on the machine even with the same parameters, and even changes over time can occur on the same machine. Automatic characteristic adjustment, which adjusts the filter characteristics, often starts with a small gain value to avoid oscillation, but if this initial gain is too small during automatic adjustment, sufficient gain cannot be obtained depending on the machine, making it difficult to determine whether resonance exists. Furthermore, if the initial gain at the start of automatic adjustment is large, oscillation may occur if there is resonance, which could potentially damage the machine.
[0005] The present disclosure has been made in view of the above-described problems, and aims to provide a technique that enables a motor control device to set an appropriate initial gain before starting automatic adjustment of filter characteristics.
[0006] a speed control loop including the speed command creation unit and the torque command creation unit; a signal input unit that inputs a signal to the speed control loop; an input / output response calculation unit that calculates an input / output response including a gain of an input / output signal of the speed control loop from an output of the speed control loop when the signal is input to the speed control loop; a condition setting unit that sets a condition for determining whether to increase the gain; a condition comparison unit that compares the input / output response calculated by the input / output response calculation unit with the condition set by the condition setting unit to confirm whether the condition for starting automatic characteristic adjustment is satisfied; and a gain setting unit that increases the gain when the condition comparison unit determines that the input / output response calculated by the input / output response calculation unit does not satisfy the condition for starting the automatic characteristic adjustment.
[0007] According to the present disclosure, it is possible to provide a technique for setting an appropriate initial gain before starting automatic adjustment of filter characteristics in a motor control device.
[0008] Fig. 1 is a block diagram showing the configuration of a motor control device according to an embodiment of the present disclosure; Fig. 2 is a graph showing the relationship between the amplitude ratio of input and output and phase delay at each frequency for explaining a second determination criterion; Fig. 3 is a graph showing the relationship between the amplitude ratio of input and output and phase delay at each frequency for explaining a third determination criterion; Fig. 4 is a flowchart showing an example of the flow of gain setting processing by a motor control device according to an embodiment of the present disclosure; Fig. 5 is a block diagram showing the configuration of a motor control device of a modified example;
[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present disclosure will now be described with reference to the accompanying drawings. Fig. 1 is a block diagram showing the configuration of a motor control device 1 according to an embodiment of the present disclosure.
[0010] The motor control device 1 controls the motor 2 via a servo amplifier or the like. The motor control device 1 is realized by executing an appropriate control program on one or more computers having a memory, a processor, an input / output interface, etc. The motor 2 is, for example, a servo motor. Note that the components of the motor control device 1 described below are classifications of the functions of the motor control device 1, and do not necessarily have to be clearly distinguishable in terms of physical configuration and program configuration.
[0011] The motor control device 1 includes a speed control loop 10 , a signal input unit 13 , an input / output response calculation unit 14 , a condition setting unit 15 , a condition comparison unit 16 , and a decrease condition determination unit 20 .
[0012] The speed control loop 10 includes a speed command generation unit 11 and a torque command generation unit 12 .
[0013] The speed command creation unit 11 creates a speed command value, which is an operation command for operating the motor 2. The speed command creation unit 11 continuously outputs a value indicating the rotation speed of the motor 2 based on operation information required of the motor 2. The operation information is, for example, data specifying the waveform of the change in speed of the motor 2, such as an operation program written in the G-code language.
[0014] Torque command creation unit 12 creates a torque command value for motor 2 based on the speed command value input from speed command creation unit 11. Torque command creation unit 12 may include an amplifier that amplifies the input or output, a filter that reduces specific frequency components of the input or output, etc. In other words, the transfer function of torque command creation unit 12 may be a polynomial function, and the characteristics of torque command creation unit 12, i.e., the transfer function, may be adjustable by modifying one or more parameters.
[0015] The speed control loop 10 is a feedback circuit that acquires feedback information from the motor 2 and reflects the feedback information in a torque command value. The feedback information is a detected value from a speed detector such as an encoder disposed on the motor 2 or a value obtained by processing the detected speed value. For example, the detected speed value is inverted and added to the speed command value, and a torque command creation unit 12 creates a torque command value to be output to the motor 2 based on the inverted and added speed command value.
[0016] The signal input unit 13 inputs a signal to the speed control loop 10. The signal input unit 13 inputs a disturbance signal or the like to the speed control loop 10 to adjust the torque command value for operating the motor 2 to an appropriate value.
[0017] The signal output from the signal input unit 13 is selected according to a response characteristic value calculated by an input / output response calculation unit 14, which will be described later. The signal output from the signal input unit 13 to the speed control loop 10 is, for example, a periodic vibration signal such as a sine wave, rectangular wave, or triangular wave, an M-sequence signal, an impulse signal, white noise, or a PRBS (Pseudo-Random Binary Sequence) signal. In this embodiment, the signal input unit 13 inputs a sine wave signal to the torque command creation unit 12.
[0018] The signal input from the signal input unit 13 is configured to sweep the frequency of the periodic measurement command, i.e., to continuously change the frequency, in order to calculate a response characteristic value indicating the frequency response characteristic in the input / output response calculation unit 14.
[0019] The input / output response calculation unit 14 estimates an input / output response that indicates response characteristics based on the signal input to the speed control loop 10 by the signal input unit 13 and the signal output from the speed control loop 10. The input / output response includes the gain of the speed control loop input / output signal.
[0020] The input / output response calculation unit 14 calculates, for example, frequency response characteristics as the input / output response. The frequency response characteristics can be obtained by inputting a sine wave signal while changing the frequency and calculating the amplitude ratio (in dB) between the input and output and the phase delay for each frequency. The input / output gain (amplitude ratio) can be expressed as in the following Equation 1. Simply put, if the speed gain is doubled, the output will also be doubled.
[0021]
[0022] The condition setting unit 15 sets conditions and information necessary to determine the initial gain for automatic characteristic adjustment. Automatic characteristic adjustment is a process of optimizing the filter parameters (setting values) of the speed control loop 10 based on the measurement results of the frequency response, and adjusting the final gain. For the automatic characteristic adjustment itself, known techniques such as those disclosed in JP 2018-128734 A can be used.
[0023] In the condition setting unit 15 of this embodiment, a gain increase condition for determining whether or not to increase the gain and a gain decrease condition for determining whether or not to decrease the gain are set.
[0024] Furthermore, a minimum gain for determining whether the initial gain has reached the minimum gain and a maximum gain for determining whether the initial gain has reached the maximum gain are set in condition setting unit 15. The minimum gain and maximum gain are set, for example, by an operator using motor control device 1 or based on parameters that are set in advance in motor control device 1. The maximum gain may be set based on a value obtained by multiplying load inertia I / motor rotor inertia I.
[0025] The initial gain is set to a small value. The gain is increased when the conditions for starting the automatic characteristic adjustment of the filter function of the speed control loop 10 are not met. If the input / output response meets the gain increase conditions, the conditions for starting the automatic characteristic adjustment are not met.
[0026] The gain increase condition of this embodiment includes a plurality of criteria (thresholds) for determining whether or not to increase the gain. Next, a first criterion, a second criterion, and a third criterion included in the plurality of criteria will be described.
[0027] The first criterion is that the maximum gain of the input / output response is equal to or greater than a first threshold value set by the condition setting unit 15. The first threshold value is set to, for example, 5 dB or greater. If the maximum gain of the input / output response is equal to or greater than the first threshold value, the gain is not increased.
[0028] The second criterion is that the frequency at which the input / output response becomes 0 dB is equal to or greater than a second threshold value set by the condition setting unit 15 .
[0029] FIG. 2 is a graph illustrating the relationship between the amplitude ratio of input and output and the phase delay at each frequency to explain the second criterion. The upper graph in FIG. 2 shows the relationship between frequency and input / output gain (amplitude ratio [dB]), and the lower graph shows the relationship between frequency and phase delay. In FIG. 2, the second criterion is set to be an input / output response of 0 dB or more up to 30 Hz. In this example, since the input / output response up to 30 Hz is 0 dB or less, the second criterion is not met, which means there is room for increasing the gain.
[0030] The third criterion is that the proportion (probability) of the gain of the input / output response calculated by the input / output response calculation unit 14 up to the set value of the frequency set by the condition setting unit 15 being 0 dB or more is equal to or greater than the third threshold value set by the condition setting unit 15.
[0031] FIG. 3 is a graph illustrating the relationship between the amplitude ratio of input and output and the phase delay at each frequency to explain the third criterion. In FIG. 3, the frequency value is set to 50 Hz, and the judgment range includes 0 Hz to 50 Hz. The third threshold is set to 50% or more. In this example, the proportion of values above 0 dB in the judgment range is clearly less than 50%, so the third criterion is not met, and there is room for increasing the gain.
[0032] In this embodiment, the gain increase condition is satisfied when the input / output response calculated by the input / output response calculation unit 14 does not satisfy any of the first to third criteria. Conversely, if any one of the first to third criteria is satisfied, the gain increase condition is not satisfied.
[0033] Note that if the initial gain has reached the maximum gain, it cannot be increased any further. Therefore, the condition for increasing the initial gain is that the gain increase condition is satisfied and the initial gain has not reached the maximum gain. In this example, the condition for increasing the gain is satisfied when any of the first, second, or third criterion is satisfied and the initial gain has not reached the maximum gain.
[0034] Next, the gain reduction conditions will be described. In this embodiment, a plurality of types of gain reduction conditions are set, including a first gain reduction condition, a second gain reduction condition, and a third gain reduction condition. Each of the gain reduction conditions will be described.
[0035] The first gain reduction condition is an oscillation condition for determining whether or not oscillation occurs when a signal is input from the signal input unit 13. There are no particular limitations on the method for setting the oscillation condition, and for example, the oscillation condition may be arbitrarily set by an operator or may be set based on the rated current of the motor, the maximum current of the amplifier, or the like.
[0036] The second gain reduction condition is a gain margin condition, which is an index of stability. Stability here refers to a state in which oscillation does not occur. The gain margin condition is determined based on the gain when the phase delay is 180 degrees in the open loop characteristics. In this case, the lower the gain, the better. There are no particular limitations on the method for setting the gain margin condition, and it can be set, for example, by using calculations, Nyquist diagrams, Bode diagrams, etc.
[0037] The third gain reduction condition is a phase margin condition, which is an index of stability. Stability here refers to a state in which oscillation does not occur. The phase margin condition is determined based on the phase when the gain is 0 dB in the open loop characteristics. In this case, the phase should be closer to 0. There are no particular limitations on the method for setting the phase margin condition, and it can be set, for example, by using calculations, Nyquist diagrams, Bode diagrams, etc.
[0038] Note that if the initial gain has reached the minimum gain, it cannot be further decreased. Therefore, the condition for decreasing the initial gain is that the gain decrease condition is satisfied and the initial gain has not reached the minimum gain. In this example, the condition for performing gain decrease is satisfied when at least one of the first to third gain decrease conditions is satisfied and the initial gain has not reached the minimum gain.
[0039] The gain increase condition and the gain decrease condition have been described above. When the initial gain becomes appropriate through gain increase, gain decrease, or the like, the appropriate gain becomes the gain during automatic characteristic adjustment. In this embodiment, the conditions for ending the gain change (gain determination) include not satisfying the gain increase condition, satisfying the gain increase condition but reaching the maximum gain, satisfying the gain decrease condition and reaching the minimum gain, etc.
[0040] Next, a description will be given of the condition comparison unit 16. The condition comparison unit 16 compares the input / output response calculated by the input / output response calculation unit 14 with the conditions set by the condition setting unit 15, and checks whether the initial gain value satisfies the conditions for starting automatic characteristic adjustment.
[0041] The condition comparison unit 16 determines whether the input / output response calculated by the input / output response calculation unit 14 satisfies the gain increase condition set by the condition setting unit 15. The condition comparison unit 16 outputs a signal to the gain setting unit 30 to determine the gain according to the determination result.
[0042] The reduction condition determination unit 20 determines whether the conditions for reducing the gain are satisfied. The reduction condition determination unit 20 of this embodiment has an oscillation determination unit 21 and a control characteristics determination unit 22 as functional units that determine the conditions for reducing the gain (first to third gain reduction conditions).
[0043] The oscillation determination unit 21 determines whether or not oscillation occurs when a signal is input from the signal input unit 13 based on a first gain reduction condition (oscillation condition).
[0044] The control characteristic determination unit 22 determines whether the input / output response calculated by the input / output response calculation unit 14 satisfies the gain margin condition or the phase margin condition based on the second gain reduction condition (gain margin condition) and the third gain reduction condition (phase margin condition).
[0045] The gain setting unit 30 changes the gain before starting automatic characteristic adjustment based on the input / output response calculated by the input / output response calculation unit 14 and various conditions set in advance. The gain setting unit 30 of this embodiment includes a gain increasing unit 31 that increases the initial gain based on the input / output response and various conditions, and a gain decreasing unit 32 that decreases the gain.
[0046] The gain increase and decrease may be linear, logarithmic, or exponential, or may be calculated from the inertia I. When calculating from the inertia I, a default value adjusted for the motor 2 alone may be multiplied by "load inertia I / motor rotor inertia I." The gain may also be increased or decreased to a preset target value. When a target value is set, the gain may be increased or decreased in stages, such as by (target value - current value) / 4. Furthermore, the gain increase and decrease methods may be changed midway through the process. For example, if the end condition for increasing the gain is that the response up to 30 Hz is 0 dB or greater, as in the example of Figure 2, the frequency with the greatest deviation from 0 dB up to 30 Hz can be selected, and the gain can be selected to compensate for that deviation. Alternatively, the gain can be selected to increase the gain by the average value up to 30 Hz. As described above, various methods can be used for increasing and decreasing the gain.
[0047] Next, the process of setting the initial gain value in the automatic characteristic adjustment will be described with reference to Fig. 4. Fig. 4 is a flowchart showing an example of the flow of the gain setting process by the motor control device 1 according to an embodiment of the present disclosure.
[0048] In step S1 , the signal input unit 13 outputs a signal such as a disturbance signal to the torque command generation unit 12 .
[0049] In step S2, the torque command generation unit 12 outputs a torque command value obtained by converting the speed command value based on the signal from the signal input unit 13. The torque command value generated by the torque command generation unit 12 is output to the motor 2 and also to the input / output response calculation unit 14.
[0050] In step S3 , the input / output response calculation unit 14 estimates the input / output response based on the signal input from the signal input unit 13 to the torque command generation unit 12 and the signal output from the torque command generation unit 12 .
[0051] In step S4, the decrease condition determination unit 20 determines whether the gain decrease condition is satisfied by performing oscillation determination by the oscillation determination unit 21 and control characteristic determination by the control characteristic determination unit 22 based on the estimated input / output response.
[0052] If all of the above oscillation condition (first gain reduction condition), gain margin condition (second gain reduction condition), and phase margin condition (third gain reduction condition) are not satisfied, the process proceeds to step S5 (step S4; No).
[0053] In step S5, the condition comparison unit 16 determines whether the gain increase condition is satisfied based on the estimated input / output response. The condition comparison unit 16 in this embodiment determines that the gain increase condition is satisfied when none of the above-mentioned first to third criteria is satisfied.
[0054] If the input / output response satisfies at least one of the first, second, and third criteria, the gain increase condition is not met, and the process proceeds to step S8 (step S5; No). In step S8, the gain setting unit 30 sets the gain as the gain for automatic characteristic adjustment as an appropriate initial gain value that does not require gain increase.
[0055] On the other hand, if the input / output response does not satisfy all of the above-mentioned first, second, and third criteria in the processing of step S5, the gain increase condition is met, and the processing proceeds to step S6 (step S5; Yes).
[0056] In step S6, the condition setting unit 15 determines whether the maximum gain has been reached. If the maximum gain has been reached, the process proceeds to step S8 (step S6; No). In step S8, the gain setting unit 30 sets the current initial gain value as the gain for automatic characteristic adjustment because the gain cannot be increased any further.
[0057] On the other hand, if the maximum gain has not been reached in the process of step S6, the process proceeds to step S7 (step S6; No). In step S7, the gain setting unit 30 executes a process of increasing the initial gain value by the gain increasing unit 31. After the process of step S7, the process returns to step S3, and the processes from step S3 onwards are repeated based on the increased initial gain value.
[0058] Furthermore, in the processing of step S4 described above, if it is determined that any one of the oscillation condition (first gain reduction condition), gain margin condition (second gain reduction condition), and phase margin condition (third gain reduction condition) is satisfied, the gain reduction condition is met and the processing proceeds to step S9 (step S4; Yes).
[0059] In step S9, the condition setting unit 15 determines whether the minimum gain has been reached. If the minimum gain has been reached, the process proceeds to step S8 (step S9; Yes). In step S8, the gain setting unit 30 sets the current initial gain value as the gain for automatic characteristic adjustment because the gain cannot be reduced any further.
[0060] On the other hand, if the minimum gain has not been reached in the process of step S9, the process proceeds to step S10 (step S9; No). In step S10, the gain setting unit 30 executes a process of decreasing the initial gain value by the gain decrease unit 32. After the process of step S10, the process returns to step S3, and the processes from step S3 onwards are repeated based on the decreased initial gain value.
[0061] In this manner, in this embodiment, the gain is increased stepwise as long as the gain increase condition is satisfied, and an optimal initial gain is searched for. This gain search is not aimed at finding the final gain value, but rather at increasing the gain to a level at which the filter can be adjusted for resonance.
[0062] The motor control device 1 of the present embodiment described above comprises: a speed command creation unit 11 that creates a speed command value for the motor 2; a torque command creation unit 12 that creates a torque command value for the motor 2 based on the speed command value; a speed control loop 10 that includes the speed command creation unit 11 and the torque command creation unit 12; a signal input unit 13 that inputs a signal to the speed control loop 10; an input / output response calculation unit 14 that calculates an input / output response including a gain of an input / output signal of the speed control loop from the output of the speed control loop 10 when a signal is input to the speed control loop 10; a condition setting unit 15 that sets a condition for determining whether or not to increase the gain; a condition comparison unit 16 that compares the input / output response calculated by the input / output response calculation unit 14 with the condition set by the condition setting unit 15 to confirm whether or not the condition for starting automatic characteristic adjustment is satisfied; and a gain setting unit 30 that increases the gain when the condition comparison unit 16 determines that the input / output response calculated by the input / output response calculation unit 14 does not satisfy the condition for starting automatic characteristic adjustment.
[0063] This prevents oscillation during automatic characteristic adjustment, improves the accuracy of the characteristics acquired during automatic characteristic adjustment, and also prevents situations where resonance cannot be detected due to too small a gain.
[0064] Furthermore, the condition comparison unit 16 of this embodiment determines or decreases the gain when the maximum gain of the input / output response calculated by the input / output response calculation unit 14 is equal to or greater than the value (first threshold value) set by the condition setting unit 15. This makes it possible to prevent oscillation during automatic characteristic adjustment caused by a momentary increase in gain.
[0065] Furthermore, the condition comparison unit 16 of this embodiment determines or decreases the gain when the frequency at which the input / output response calculated by the input / output response calculation unit 14 becomes 0 dB is equal to or greater than the value (second threshold value) set by the condition setting unit 15. This allows the gain to be increased to a level at which resonance can be determined.
[0066] Furthermore, the condition comparison unit 16 of this embodiment determines or decreases the gain when the rate at which the gain of the input / output response calculated by the input / output response calculation unit 14 is 0 dB or more up to the frequency value set by the condition setting unit 15 is equal to or greater than the value (third threshold) set by the condition setting unit 15. This allows the gain to be increased to a level at which resonance can be determined.
[0067] The present embodiment further includes an oscillation determination unit 21 that determines whether oscillation occurs when a signal is input to the signal input unit 13. This makes it possible to more reliably determine whether oscillation occurs when automatic characteristic adjustment is performed.
[0068] Furthermore, when the oscillation determination unit 21 of this embodiment determines that oscillation has occurred, the gain is fixed or reduced, thereby more reliably preventing the occurrence of oscillation when automatic characteristic adjustment is performed.
[0069] The present embodiment further includes a control characteristic determination unit 22 that determines whether the input / output response calculated by the input / output response calculation unit 14 satisfies the gain margin or phase margin set by the condition setting unit 15. This makes it possible to determine whether the stability is high or low because the gain margin or phase margin is not satisfied before the automatic characteristic adjustment.
[0070] Furthermore, when the control characteristic determination unit 22 of this embodiment determines that the gain margin or phase margin is not satisfied, the gain is determined or reduced, thereby preventing the automatic characteristic adjustment from being performed in a state of low stability due to the gain margin or phase margin not being satisfied.
[0071] Furthermore, the gain is determined when the gain of the input / output response calculated by the input / output response calculation unit 14 of this embodiment is the maximum gain set by the condition setting unit 15. This makes it possible to avoid the occurrence of a situation in which the gain is increased beyond the maximum gain set in advance as a condition.
[0072] The motor control device 1a of this embodiment also includes a speed detection unit 17 that detects the speed of the motor 2 driven based on the torque command value. This makes it possible to calculate an input / output response using the detection result of the speed detection unit 17, and to determine whether the initial gain satisfies the conditions for starting automatic characteristic adjustment based on the calculated input / output response.
[0073] The motor control device 1 according to one embodiment of the present disclosure has been described above, but the configuration of the motor control device 1 can be modified as appropriate. Next, the configuration of a modified motor control device 1 will be described. Note that in the following description, configurations that are common or similar to those in the above embodiment will be assigned the same reference numerals and descriptions thereof may be omitted.
[0074] 5 is a block diagram showing the configuration of a modified motor control device 1a. As shown in FIG. 5, the modified motor control device 1a includes a speed detection unit 17 in the speed control loop 10.
[0075] In this modification, the signal input unit 13 inputs a signal required to generate a speed command value to the speed command generation unit 11 of the speed control loop 10. The speed command generation unit 11 generates a speed command value based on the signal input from the signal input unit 13 and outputs it to the torque command generation unit 12. The torque command generation unit 12 outputs the torque command value input from the speed command generation unit 11. The torque command value is output to the motor 2 via a servo amplifier or the like (not shown), and the motor 2 is driven based on the torque command value.
[0076] The speed detector 17 detects the speed of the motor 2 driven based on the torque command value. The speed detector 17 outputs information indicating the speed fed back from the motor 2 to the input / output response calculator 14.
[0077] The input / output response calculation unit 14 acquires the input signal input from the signal input unit 13 to the speed command creation unit 11 and the output signal output from the speed detection unit 17. The input / output response calculation unit 14 estimates and calculates the input / output response based on the acquired input and output signals. The input / output response calculation unit 14 outputs the calculated input / output response to the reduction condition determination unit 20. Note that the subsequent processing and configuration are the same as those in the above embodiment, and therefore detailed description thereof will be omitted.
[0078] The configuration of the motor control device 1a of this modified example also makes it possible to appropriately set the gain for automatic characteristic adjustment, similar to the motor control device 1 of the above-described embodiment.
[0079] In the above embodiment, the first, second, and third judgment criteria are conditions for determining whether to increase the gain, but they may also be conditions for decreasing the gain. The number of judgment criteria set as the gain increase condition may be one, and the number of gain decrease conditions may be one. In this way, the conditions and criteria for increasing or decreasing the gain can be changed as appropriate.
[0080] The following supplementary note is further disclosed regarding the above embodiment: (Supplementary Note 1) The motor control device (1, 1a) comprises: a speed command creation unit (11) that creates a speed command value for a motor (2), a torque command creation unit (12) that creates a torque command value for the motor (2) based on the speed command value, a speed control loop (10) including the speed command creation unit (11) and the torque command creation unit (12), a signal input unit (13) that inputs a signal to the speed control loop, an input / output response calculation unit (14) that calculates an input / output response including a gain of an input / output signal of the speed control loop from an output of the speed control loop (10) when the signal is input to the speed control loop (10), a condition setting unit (15) that sets a condition for determining whether to increase the gain, and a condition comparison unit (16) that compares the input / output response calculated by the input / output response calculation unit (14) with the condition set by the condition setting unit (15) to confirm whether the condition for starting automatic characteristic adjustment is met. and a gain setting unit (30) that increases the gain when the condition comparison unit (16) determines that the input / output response calculated by the input / output response calculation unit (14) does not satisfy the conditions for starting the automatic characteristic adjustment.
[0081] (Supplementary Note 2) In the above motor control device (1, 1a), the condition comparison unit (16) may confirm or decrease the gain when the maximum gain of the input / output response calculated by the input / output response calculation unit (14) is equal to or greater than the value set by the condition setting unit (15).
[0082] (Supplementary Note 3) In the above motor control device (1, 1a), the condition comparison unit (16) may confirm or decrease the gain when the maximum gain of the input / output response calculated by the input / output response calculation unit (14) is equal to or greater than the value set by the condition setting unit (15).
[0083] (Supplementary Note 4) In the above motor control device (1, 1a), the condition comparison unit (16) may confirm or decrease the gain when a rate at which the gain of the input / output response calculated by the input / output response calculation unit is 0 dB or more up to the frequency value set by the condition setting unit (15) is equal to or greater than a value set by the condition setting unit (15).
[0084] (Supplementary Note 5) The motor control device (1, 1a) may further include an oscillation determination unit (21) that determines whether oscillation occurs when the signal is input to the signal input unit (13).
[0085] (Supplementary Note 6) In the motor control device (1, 1a), the gain may be fixed or decreased when the oscillation determination unit (21) determines that oscillation has occurred.
[0086] (Supplementary Note 7) The motor control device (1, 1a) may further include a control characteristic determination unit (22) that determines whether the input / output response calculated by the input / output response calculation unit (14) satisfies the gain margin or phase margin set by the condition setting unit (15).
[0087] (Supplementary Note 8) In the motor control device (1, 1a), the control characteristic determination unit (22) may determine or decrease the gain when the gain margin or the phase margin is not satisfied.
[0088] (Supplementary Note 9) In the motor control device (1, 1a), the gain may be determined when the gain of the input / output response calculated by the input / output response calculation unit (14) is a maximum gain set by the condition setting unit (15).
[0089] (Supplementary Note 10) The motor control device (1) may further include a speed detection unit (17) that detects the speed of the motor driven based on the torque command value.
[0090] Although the present disclosure has been described in detail above, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values or mathematical expressions are used in the description of the above-described embodiments.
[0091] REFERENCE SIGNS LIST 1, 1a Motor control device 2 Motor 10 Speed control loop 11 Speed command creation unit 12 Torque command creation unit 13 Signal input unit 14 Input / output response calculation unit 15 Condition setting unit 16 Condition comparison unit 17 Speed detection unit 21 Oscillation determination unit 22 Control specification determination unit 30 Gain setting unit
Claims
a speed control loop including the speed command creation unit and the torque command creation unit; a signal input unit that inputs a signal to the speed control loop; an input / output response calculation unit that calculates an input / output response including a gain of an input / output signal of the speed control loop from an output of the speed control loop when the signal is input to the speed control loop; a condition setting unit that sets a condition for determining whether to increase the gain; a condition comparison unit that compares the input / output response calculated by the input / output response calculation unit with the condition set by the condition setting unit to confirm whether the condition for starting automatic characteristic adjustment is met; and a gain setting unit that increases the gain when the condition comparison unit determines that the input / output response calculated by the input / output response calculation unit does not meet the condition for starting automatic characteristic adjustment.
2. The motor control device according to claim 1, wherein the condition comparison unit determines or reduces the gain when the maximum gain of the input / output response calculated by the input / output response calculation unit is equal to or greater than the value set by the condition setting unit.
3. A motor control device as described in claim 1 or 2, wherein the condition comparison unit determines or reduces the gain when the frequency at which the input / output response calculated by the input / output response calculation unit becomes 0 dB is equal to or greater than the value set by the condition setting unit.
4. A motor control device as described in any one of claims 1 to 3, wherein the condition comparison unit confirms or reduces the gain when the proportion of the input / output response calculated by the input / output response calculation unit where the gain is 0 dB or more up to the frequency value set by the condition setting unit is equal to or greater than the value set by the condition setting unit.
5. The motor control device according to any one of claims 1 to 4, further comprising an oscillation determination unit that determines whether oscillation occurs when the signal is input to the signal input unit.
6. The motor control device according to claim 5, wherein the gain is either fixed or reduced when the oscillation determination unit determines that oscillation has occurred.
7. A motor control device according to any one of claims 1 to 6, further comprising a control characteristics determination unit that determines whether the input / output response calculated by the input / output response calculation unit satisfies the gain margin or phase margin set by the condition setting unit.
8. The motor control device according to claim 7, wherein the gain is fixed or reduced when the control characteristic determination unit determines that the gain margin or the phase margin is not satisfied.
9. A motor control device according to any one of claims 1 to 8, wherein the gain is determined when the gain of the input / output response calculated by the input / output response calculation unit is the maximum gain set by the condition setting unit.
10. The motor control device according to any one of claims 1 to 9, further comprising a speed detection unit that detects the speed of the motor driven based on the torque command value.