JP2010049362A - Gain adjustment device, gain adjustment method and gain adjustment program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gain adjustment device, a gain adjustment method and a gain adjustment program, which enable high-accuracy adjustment of a loop gain by reducing effect of disturbance fluctuation. <P>SOLUTION: In the loop gain adjustment of a closed loop circuit, the loop gain adjustment is executed a plurality of times to converge the loop gain. After a value of the loop gain converges, a value obtained by averaging loop gain adjustment results of a frequency properly set in consideration of the effect of the disturbance fluctuation is set as a final value of the loop gain. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a gain adjustment device, a gain adjustment method, and a gain adjustment program for adjusting a closed-loop gain.

  Conventionally, in a closed loop circuit, there is a method of adjusting the loop gain to be constant by suppressing the fluctuation of the loop characteristic due to the fluctuation of the parameter to be controlled or the circuit. In this method, a reference signal having a predetermined frequency is externally supplied to the closed loop circuit, and only a response signal that makes a round of the closed loop circuit with respect to the reference signal is obtained by a bandpass filter (hereinafter referred to as BPF) having the predetermined frequency of the reference signal as a center frequency. Extract. Then, measure the phase difference between the reference signal and the extracted response signal, calculate the loop gain value so that the phase difference approaches the predetermined target value, and switch the loop gain to the calculated value to adjust the loop gain. I do.

  In addition, a series of loop gain adjustments consisting of reference signal supply, phase difference measurement, loop gain calculation, and loop gain change are executed multiple times, and loop gain correction is repeated automatically. The loop gain is converged to a value at which a desired loop characteristic can be obtained.

Patent Document 1 describes a method and an apparatus for adjusting characteristics of an electronic circuit that can perform accurate adjustment of loop characteristics and the like.
Japanese Patent No. 3429162

  However, if the controlled object in the closed-loop circuit is a device such as a motor, the rotor may be deviated due to variations in the magnetization of the motor or the eccentricity of the rotor and the structure connected to the motor output shaft directly or through a gear. In many cases, there are large disturbance fluctuations at a specific frequency such as the rotation speed or an integer multiple thereof.

  In the conventional method described above, when the frequency of disturbance fluctuation is close to the frequency of the reference signal, disturbance fluctuation cannot be sufficiently attenuated even in the subsequent stage of the BPF that extracts the response signal to the basic signal. For this reason, in the conventional adjustment method, the corrected loop gain value does not converge completely due to the influence of disturbance fluctuations included in the response signal, and fluctuations remain. As a result, the loop gain adjustment result is different every time adjustment is performed, and the adjustment accuracy is significantly deteriorated.

  The present invention has been made in view of the above circumstances, and has been made to solve this problem, and is capable of reducing the influence of disturbance fluctuation and adjusting the loop gain with high accuracy, a gain adjustment method, The purpose is to provide a gain adjustment program.

  The present invention employs the following configuration in order to achieve the above object.

  The present invention measures a phase difference between a reference signal of a predetermined frequency supplied to a closed loop circuit and a response signal extracted at a position that makes a round of the closed loop circuit from a position where the reference signal is input, and the phase difference Is a gain adjustment device that adjusts the loop gain of the closed loop circuit so as to be close to a predetermined target value, and each time the loop gain is adjusted, a value of the loop gain that brings the phase difference close to the predetermined target value is calculated Calculating means, and changing means for changing the value of the loop gain of the closed loop circuit, and the changing means calculates the value of the loop gain of the closed loop circuit after the adjustment of the loop gain is performed a plurality of times. Each time the loop gain is adjusted, the average value of the loop gain values calculated by the calculating means is changed.

  In the gain adjustment device according to the present invention, the number of the loop gain values used for obtaining the average value in the plurality of loop gain adjustments may include the frequency of the reference signal and the frequency of the reference signal. A value obtained by dividing the absolute value of the difference from the disturbance fluctuation frequency included in the response signal is preferable.

  Further, the gain adjusting device of the present invention is configured so that the magnitude of the disturbance fluctuation included in the response signal is within a predetermined range based on the reference signal supplied for a plurality of cycles and the response signal extracted for each cycle. And a reference signal generation unit configured to change the frequency of the reference signal when it is determined that the disturbance fluctuation is not within a predetermined range. preferable.

  Further, in the gain adjustment device of the present invention, the disturbance fluctuation determining means is configured such that a phase difference fluctuation range that is a difference between a maximum value and a minimum value of a phase difference from the response signal extracted for each period is not within a predetermined range. It is preferable that the magnitude of the disturbance fluctuation is determined not to fall within a predetermined range.

  In the gain adjusting apparatus of the present invention, the disturbance fluctuation determining means has an amplitude fluctuation range that is a difference between the maximum value and the minimum value of the amplitude of the response signal extracted from the reference signal for each period within a predetermined range. When there is no disturbance, it is preferable that the magnitude of the disturbance fluctuation is determined not to be within a predetermined range.

  The present invention measures a phase difference between a reference signal of a predetermined frequency supplied to a closed loop circuit and a response signal extracted at a position that makes a round of the closed loop circuit from a position where the reference signal is input, and the phase difference Is a gain adjustment method by a gain adjustment device that adjusts the loop gain of the closed loop circuit so as to be close to a predetermined target value, and each time the loop gain is adjusted, the gain of the loop gain that makes the phase difference close to the predetermined target value A calculation procedure for calculating a value, and a change procedure for changing a loop gain value of the closed loop circuit, the change procedure including a loop of the closed loop circuit after the adjustment of the loop gain is performed a plurality of times. The gain value is changed to the average value of the loop gain values calculated by the calculation procedure every time the loop gain is adjusted.

  The present invention measures a phase difference between a reference signal of a predetermined frequency supplied to a closed loop circuit and a response signal extracted at a position that makes a round of the closed loop circuit from a position where the reference signal is input, and the phase difference Is a gain adjustment program that is executed in a gain adjustment device that adjusts the loop gain of the closed-loop circuit so as to approach a predetermined target value, and each time the loop gain is adjusted in the gain adjustment device, a phase difference is calculated. A calculation step for calculating a loop gain value that approaches a predetermined target value and a change step for changing the loop gain value of the closed-loop circuit are executed. In the change step, the loop gain adjustment is executed a plurality of times. After that, the loop gain value of the closed loop circuit is calculated by the calculation step every time the loop gain is adjusted. Was a program to change the average value of the value of Pugein.

  According to the present invention, the influence of disturbance fluctuation can be reduced and the loop gain can be adjusted with high accuracy.

  In the present invention, in the loop gain adjustment of the closed loop circuit, the loop gain adjustment is performed a plurality of times to converge the loop gain, and after the loop gain value has converged, the number of times appropriately set in consideration of the influence of disturbance fluctuation The value obtained by averaging the loop gain adjustment results in is used as the final loop gain value.

(First embodiment)
A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating the configuration of a gain adjustment device 100 according to the first embodiment.

  In the present embodiment, the gain adjustment device 100 adjusts the loop gain of a closed loop circuit that controls the motor 10, for example. The rotational speed of the motor 10 is controlled by a closed loop circuit. The drive circuit 20 supplies a drive current for driving the motor 10 in accordance with an input signal indicating a drive level. The detection unit 30 detects the rotation speed of the motor 10. Specifically, the detection unit 30 of the present embodiment is a rotary encoder connected to the output shaft of the motor 10 and converts the rotation speed of the motor 10 into a pulse signal and outputs the pulse signal.

  In the present embodiment, disturbance fluctuations caused by the eccentricity of the rotor of the motor 10 are input to the closed loop circuit in which the loop gain is controlled by the gain adjusting device 100.

  Below, the gain adjustment apparatus 100 of this embodiment is demonstrated.

  The gain adjusting apparatus 100 according to the present embodiment is realized by a function of software that operates on a DSP (digital signal processor). Hereinafter, a functional configuration of the gain adjusting apparatus 100 of the present embodiment will be described.

  The gain adjustment apparatus 100 includes a speed error detection unit 110, a servo calculation unit 120, and a loop gain automatic adjustment unit 130.

  The speed error detection unit 110 outputs an error control signal a1 based on the output signal output from the detection unit 30 and the signal indicating the control target speed. The control target speed is determined in advance according to the specifications of the main body device on which the gain adjusting device 100 is mounted.

  When the error control signal a1 is input, the servo calculation unit 120 performs calculation and outputs a speed control signal a2 for controlling the rotation speed of the motor 10. The configuration of the servo calculation unit 120 of this embodiment is shown in FIG. As shown in FIG. 2, the servo calculation unit 120 according to the present embodiment includes a speed proportional system, a speed integration phase system, and a low-frequency boost filter.

  Returning to FIG. 1, the loop gain automatic adjustment unit 130 of this embodiment includes an automatic adjustment control unit 131, a reference signal generation unit 132, an addition unit 133, a correction gain 134, a BPF 135, a phase difference measurement unit 136, and a gain change unit 137. Have

  The automatic adjustment control unit 131 issues an operation instruction to each unit described later in order to perform an automatic adjustment operation of the loop gain. The reference signal generation unit 132 receives the operation instruction from the automatic adjustment control unit 131 and generates a reference signal b1 having a predetermined frequency and a predetermined amplitude. Note that the reference signal of this embodiment is a sine wave.

  The adder 133 supplies the reference signal generated by the reference signal generator 132 to the closed loop circuit.

  The correction gain 134 is a loop gain incorporated in advance in the closed loop circuit. In this embodiment, the value of the initial correction gain 134 (loop gain) before the loop gain adjustment by the loop gain automatic adjustment unit 130 is 1, and the gain change is performed when the loop gain adjustment is executed. The unit 137 changes the loop characteristic to a value that corrects the target characteristic.

  The BPF 135 is a BPF whose center frequency is the frequency of the reference signal b1. The BPF 135 of this embodiment extracts the response signal b2 from the position where the reference signal b1 supplied to the closed loop circuit by the adder 133 makes a round of the closed loop circuit.

  The phase difference measuring unit 136 measures the phase difference between the reference signal b1 and the response signal b2, and outputs phase difference data b3. As shown in FIG. 3, the phase difference measuring unit 136 of the present embodiment detects a point where the waveform of the reference signal b1 and the waveform of the response signal b2 cross each other, and measures the phase difference between the two signals. And FIG. 3 is a diagram for explaining phase difference measurement by the phase difference measurement unit 136. Furthermore, in the present embodiment, for the response signal b2, by setting the reference for phase difference measurement to a point where the phase is inverted by -180 degrees, the time for phase difference measurement is shortened and the loop gain adjustment time is shortened.

  Returning to FIG. 1, the gain changing unit 137 sets the loop gain value that brings the loop characteristic closer to the target based on the current value of the correction gain 134 and the error between the measured phase difference and the predetermined target phase difference. Then, the correction gain 134 is changed to the calculated value. Details of the loop gain value calculation method will be described later.

  Next, the operation of the loop gain automatic adjustment unit 130 of this embodiment will be described with reference to FIGS. 4 and 5. FIG. 4 is a first flowchart for explaining the operation of the loop gain automatic adjustment unit 130. FIG. 5 is a second flowchart for explaining the operation of the loop gain automatic adjustment unit 130.

  In the present embodiment, one phase difference measurement is performed for one period of the reference signal b1. In the present embodiment, calculating the loop gain value with respect to the phase difference measured by one phase difference measurement and changing the value of the correction gain 134 by the gain changing unit 137 is one loop gain adjustment. To do. First, a single loop gain adjustment operation will be described with reference to FIG.

  When the loop gain adjustment starts in step S41, the loop gain automatic adjustment unit 130 causes the reference signal generation unit 132 to generate a reference signal b1 having a predetermined frequency and amplitude, and the addition unit 133 outputs the reference signal b1 to the closed loop circuit. Start supplying. Progressing to step S42 following step S41, the phase difference measuring unit 136 detects a zero cross point between the waveform of the reference signal b1 and the waveform of the response signal b2, and starts phase difference measurement. Following step S42, the process proceeds to step S43, and after the phase difference measurement is completed, the gain changing unit 137 calculates the next loop gain value based on the measured phase difference.

  Proceeding to step S44 following step S43, the gain changing unit 137 waits until the supply for the period of the reference signal b11 is completed. Progressing to step S45 following step S44, the gain changing unit 137 changes the correction gain 134 to the calculated loop gain value.

  The above is one loop gain adjustment operation. In the present embodiment, it is assumed that the BPF 135 has started operation in advance.

  Furthermore, the loop gain is converged to the target accurately by repeating the above loop gain adjustment for a plurality of cycles, which is called loop gain automatic adjustment. The loop gain automatic adjustment operation will be described below with reference to FIG.

  When automatic loop gain adjustment is started in the automatic loop gain adjustment unit 130, the process proceeds to step S51. In step S51, in order to wait until the BPF 135 is settled, the reference signal generator 132 and the adder 133 supply the reference signal b1 for a predetermined period to the closed loop circuit. Proceeding to step S52 following step S51, the loop gain automatic adjustment unit 130 initializes n by setting the loop gain adjustment repetition count to n.

  Progressing to step S53 following step S52, the loop gain automatic adjustment unit 130 executes the loop gain adjustment described with reference to FIG. 4 once. Following step S53, the process proceeds to step S54. In step S54, the predetermined number of loop gain adjustment iterations is set to Nlga, and the number of data for which the loop gain adjustment result is averaged later is set to Nave (Nlga> Nave). If n ≧ (Nlga−Nave) in step S54, the process proceeds to step S55, and the gain changing unit 137 uses the loop gain value Gadj (n + 1) calculated by the loop gain adjustment in step S53 as the next loop gain. Save as a value to be used for adjustment.

  Subsequent to step S55, the process proceeds to step S56, where the repeat count is incremented by 1, and n = (n + 1). Progressing to step S57 following step S56, when the loop gain adjustment has not been performed a predetermined number of times Nlga, the process returns to step S53, and the loop gain adjustment of the next cycle is performed again.

  In step S57, when the loop gain adjustment is completed a predetermined number of times, the process proceeds to step S58. In step S58, the gain changing unit 137 calculates the average value of the Nave loop gain values stored in step S55.

  Here, assuming that the value of the loop gain is Gadj and the value of the loop gain is Gadj (n) when the repetition count is n, the average value of the values of the loop gain is calculated by the following equation (1).

  Proceeding to step S59 following step S58, the gain changing unit 137 changes the correction gain 134 to the calculated average value of the loop gain, and ends the process. The above is the operation of loop gain automatic adjustment.

  The DSP that implements the loop gain automatic adjustment unit 130 of the present embodiment includes counter means and storage means (not shown). The repeated counting of the loop gain automatic adjustment described with reference to FIG. Further, the value of the correction gain is stored in, for example, a storage unit included in the DSP.

  Next, a method for calculating a loop gain value in the present embodiment will be described.

  First, in the loop gain adjustment, the target value of the phase difference to be measured is set as the target phase difference. The target phase difference is a value of the phase characteristic of the closed loop circuit targeted at the frequency (hereinafter referred to as fsin) of the reference signal b1 supplied to the closed loop circuit, and is set in advance as a value calculated from actual measurement or a model formula. . However, in the present embodiment, the phase of the response signal b2 is inverted in the phase difference measurement as shown in FIG.

  Therefore, if the target phase difference is positive in the direction in which the phase of the response signal b2 is delayed with respect to the reference signal b1, the phase characteristic value θ0 of the target closed loop circuit at the reference signal frequency fsin is shown in FIG. Is used to set the target phase difference to (180−θ0) [deg]. FIG. 6 is a diagram illustrating frequency characteristics and a target phase difference of the closed loop circuit in the first embodiment. In many cases, the frequency of the reference signal b1 to be supplied is set near the crossover frequency. However, as described above, if the value of the phase characteristic of the target closed-loop circuit is set at the frequency of the reference signal b1. The frequency of the reference signal b1 is not limited to the vicinity of the crossover frequency.

  Next, the difference between the measured phase difference and the target phase difference is defined as a phase difference error PE, and the phase difference error at the repetition count n in the above loop gain automatic adjustment is defined as PE (n). Similarly, the value of the loop gain is Gadj, and similarly, the value of the loop gain is Gadj (n) when the repetition count is n. Further, using the adjustment sensitivity coefficient kadj that affects the convergence to the target value due to repeated loop gain automatic adjustment, the value of the next loop gain is calculated by the equation shown in equation (2). The loop gain automatic adjustment that repeats the correction according to Expression (2) is an error integration algorithm, and by setting an appropriate adjustment sensitivity kadj, the loop gain value approaches the target each time the loop gain automatic adjustment is repeated. .

  Next, a case where disturbance fluctuations input to the closed loop circuit deteriorate the result of loop gain automatic adjustment will be described. In the present embodiment, a case is considered in which disturbance fluctuation having a large amplitude is input to the rotational speed frequency in the motor 10 due to the eccentricity of the rotor.

  First, an example showing the influence when the BPF 135 cannot sufficiently attenuate the disturbance fluctuation is shown. For example, the correction gain 134 is fixed, the frequency fsin = 32.55 [Hz] of the reference signal b1 is continuously supplied, and the phase difference is measured for each cycle of the reference signal b1.

  Further, when the rotation speed of the motor is 1800 rpm, disturbance fluctuation with a disturbance fluctuation frequency fn = 30 [Hz] is input. At this time, it is assumed that the reference signal b1 and the disturbance fluctuation frequency fn are close to each other, and the disturbance signal that cannot be sufficiently attenuated is included in the response signal b2 that is the output of the BPF 135. FIG. 7 and FIG. 8 show simulation results showing how the phase difference fluctuates for each measurement when the amplitude of disturbance fluctuation included in the response signal b2 is 20% of the sine wave of the response signal b2.

FIG. 7 is a diagram illustrating waveforms of the reference signal b1 and the response signal b2. However, in FIG. 7, the response signal b2 is inverted between positive and negative so that it is easy to see how the phase difference fluctuates. FIG. 8 is a diagram showing a result of measuring the phase difference shown in FIG. 3 in the waveform of FIG. According to FIG. 8, it can be seen that the measured phase difference has periodicity, and this time, it is understood that every about 13 periods. And this cycle is
fsin / (| fsin−fn |)
Can be represented by In the example shown in FIG. 8, fsin = 32.55 [Hz] and fn = 30 [Hz]. Therefore, the phase difference period is
(32.55 / (32.55-30)) = 12.76
Thus, it can be seen that this period coincides with the periodicity read from FIG. In addition, the amplitude of the fluctuation in the phase difference increases as the amplitude of the disturbance fluctuation increases relative to the amplitude of the response of the reference signal b1.

  Next, the influence of the above-described disturbance fluctuation on loop gay automatic adjustment will be described with reference to FIG. FIG. 9 shows a change in the loop gain value when the loop gain automatic adjustment is performed for the closed loop circuit in which the controller is designed by intentionally reducing the gain to 2/3 of the target characteristic. ing. It is assumed that the frequency fsin = 32.55 [Hz] of the reference signal b1 to be supplied.

  The filled diamonds shown in FIG. 9 indicate the change in the loop gain value in the loop gain automatic adjustment when disturbance variation is included in the present embodiment. In the present embodiment, the rotational speed of the motor 10 is 1800 rpm, and has a disturbance fluctuation with a disturbance frequency fn = 30 [Hz] (not shown).

  A white circle shown in FIG. 9 indicates a change in the value of the correction gain in the automatic loop gain adjustment by simulation, and disturbance fluctuation is not taken into consideration. Although the loop gain value to be converged is slightly different due to an error between the present embodiment and the simulation, when there is no disturbance fluctuation, it converges to a substantially constant value after 10 or fewer loop gain adjustments. Similarly, in this embodiment including disturbance fluctuation, the loop gain converges by repetition of loop gain adjustment, but it can be seen that periodic fluctuation remains due to the influence of disturbance fluctuation that cannot be sufficiently attenuated by the BPF 135.

  As described above, when the disturbance fluctuation cannot be sufficiently attenuated, that is, when there is a large disturbance fluctuation in the vicinity of the frequency of the supplied reference signal b1, a periodic fluctuation remains in the loop gain adjustment result. I understand that.

  Therefore, in the automatic loop gain adjustment of the present invention, the average value of the results of multiple loop gain adjustments is used as the final value of the loop gain value, so that the effect of periodic fluctuations in the loop gain value due to disturbance fluctuations can be obtained. Reduce. Furthermore, in the present embodiment, when the disturbance fluctuation frequency is known, the number Nave of the results obtained by averaging in the loop gain automatic adjustment is canceled as follows so as to cancel the periodic fluctuation of the loop gain value due to the disturbance fluctuation. Can be set.

Nave = m (fsin / | fsin−fn |) (m is a natural number)
If (fsin / | fsin−fn |) is not an integer, the decimal part is rounded up or down.

  In the present embodiment, by setting the value calculated by the above formula to Nave, it is possible to cancel (reduce) the variation in the adjustment results having the periodicity shown in FIGS. 8 and 9 with a smaller number of results. .

  As described above, in the present embodiment, in the loop gain adjustment of the closed loop circuit, the loop gain adjustment is executed a plurality of times to converge the loop gain, and after the loop gain value has converged, the influence of the disturbance fluctuation is appropriately considered. A value obtained by averaging the loop gain adjustment results for the set number of times is set as a final loop gain value. In the present embodiment, with this configuration, it is possible to reduce the influence of the disturbance fluctuation of the frequency that cannot be sufficiently attenuated by the BPF 135, and obtain an accurate loop gain adjustment result.

(Second embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. The second embodiment of the present invention is different from the first embodiment in that a disturbance fluctuation determination operation is performed before loop gain automatic adjustment. Therefore, in the following description of the second embodiment, only differences from the first embodiment will be described, and those having the same functional configuration as the first embodiment will be described in the description of the first embodiment. The same reference numerals as those used are assigned, and the description thereof is omitted.

  In the present embodiment, the disturbance fluctuation determination operation is performed before the loop gain automatic adjustment, thereby further reducing the influence of the disturbance fluctuation and obtaining an accurate loop gain adjustment result.

  FIG. 10 is a diagram illustrating the configuration of the gain adjustment device 100A of the second embodiment. The gain adjustment apparatus 100A of the present embodiment includes a loop gain automatic adjustment unit 130A.

  The loop gain automatic adjustment unit 130A includes an automatic adjustment control unit 131A, a reference signal generation unit 132A, an addition unit 133, a correction gain 134, a BPF 135A, a phase difference measurement unit 136, a gain change unit 137A, and a phase difference variation determination unit 138.

  The loop gain automatic adjustment unit 130A of the present embodiment performs a disturbance variation determination operation before performing loop gain automatic adjustment. The disturbance determination operation is an operation of supplying the reference signal b1 to the closed loop circuit for a predetermined period and determining whether the influence of disturbance fluctuation on the response signal b2 is within a predetermined range based on the response signal b2 to the reference signal b1. . Details of the disturbance fluctuation determination operation will be described later.

  The automatic adjustment control unit 131A issues an operation instruction for instructing execution of a disturbance variation determination operation described later. Further, the automatic adjustment control unit 131A issues an operation instruction to each unit in order to execute the loop gain automatic adjustment operation.

  The reference signal generator 132A generates reference signals b1 having a plurality of preset frequencies and amplitudes. The frequency and amplitude of the reference signal b1 are selected by a signal from the automatic adjustment control unit 131A.

  The BPF 135A is a BPF whose center frequency is the frequency of the reference signal b1, and when the frequency of the reference signal b1 is changed, the center frequency of the BPF 135A becomes the frequency of the reference signal b1 by the signal of the automatic adjustment control unit 131A. Change the settings so that

  When the frequency of the reference signal b1 is changed, the gain changing unit 137A uses the signal of the automatic adjustment control unit 131A to adjust the correction gain 134 () to the target phase difference set in advance corresponding to the changed frequency of the reference signal b1. Change the loop gain.

  The phase difference variation determination unit 138 stores phase difference data b3 that is an output of the phase difference measurement unit 136 in the disturbance variation determination operation. Further, in the disturbance variation determination operation, the phase difference variation determination unit 138 calculates a phase difference variation range which is a difference between the maximum value and the minimum value of the stored phase difference after the predetermined number of phase difference measurements are completed. Then, the phase difference variation determination unit 138 determines whether or not the phase difference variation range of the calculation result is larger than a predetermined value, and outputs the determination result to the automatic adjustment control unit 131A.

  In this embodiment, when the phase difference fluctuation range is within the predetermined range, it is determined that the disturbance fluctuation is within the predetermined range. When the phase difference fluctuation range is outside the predetermined range, the disturbance fluctuation is outside the predetermined range. Is determined. That is, in the present embodiment, the phase difference variation determination unit 138 serves as a disturbance variation determination unit.

  Here, disturbance fluctuations and phase difference fluctuations will be described with reference to FIG. FIG. 11 shows the results when the reference signal is continuously supplied and the phase difference is measured for each period. However, the response signal b2 includes a fluctuation disturbance that cannot be sufficiently attenuated by the BPF 135A. In the example shown in FIG. 11, a sine wave having a reference signal frequency fsin = 32.55 [Hz] and a disturbance fluctuation frequency fn = 30 [Hz] is used.

  The white circle in FIG. 11 shows the measurement result of the phase difference when the disturbance fluctuation amplitude included in the response signal b2 is 20% of the response amplitude of the reference signal b1. Black squares in FIG. 11 show the measurement results of the phase difference when the amplitude of the disturbance fluctuation included in the response signal b2 is 30% with respect to the amplitude of the response of the reference signal b1.

  According to FIG. 11, it can be seen that the greater the fluctuation in disturbance with respect to the response of the reference signal b1, the greater the fluctuation in the phase difference to be measured.

  Hereinafter, the disturbance fluctuation determination operation of the present embodiment will be described with reference to FIG. FIG. 12 is a flowchart for explaining a disturbance variation determination operation in the second embodiment.

  When the disturbance variation determination operation starts in the loop gain automatic adjustment unit 130A, the process proceeds to step S1201. In step S1201, the reference signal generation unit 132A and the addition unit 133 supply the reference signal b1 for a predetermined period to the closed loop circuit in order to wait until the BPF 135A is settled. Progressing to step S1202 following step S1201, the phase difference measurement count is set to n, and n is initialized.

  Progressing to step S1203 following step S1202, the reference signal generation unit 132A and the addition unit 133 start supplying the reference signal b1 for one cycle to the closed loop circuit. Progressing to step S1204 following step S1203, the phase difference measuring unit 136 measures the phase difference between the reference signal b1 and the response signal b2. When the phase difference measurement is completed in step S1204, the process proceeds to step S1205, and the phase difference is stored.

  Following step S1205, the process proceeds to step S1206, waits until the supply of the reference signal b1 of one cycle is completed, and then proceeds to step S1207. In step S1207, the phase difference measurement count is incremented by 1, so that n = n + 1. Progressing to step S1208 following step S1207, it is determined whether or not the phase difference measurement has been performed a predetermined number of times. In FIG. 12, the predetermined number of times is indicated as Nchn.

  If the number of executions of phase difference measurement has not reached the predetermined number Nchn in step S1208, the process returns to step S1203, and the processing from step S1203 is repeated.

  If the number of executions of phase difference measurement has reached the predetermined number Nchn in step S1208, the process proceeds to step S1209. In step S1209, the phase difference fluctuation determination unit 138 calculates a phase difference fluctuation width that is the difference between the stored maximum value and minimum value of the phase difference, and whether or not the phase difference fluctuation width is within a predetermined range. And the determination result is output to the automatic adjustment control unit 131A.

  In step S1209, when the phase difference fluctuation range is within the predetermined range, the automatic adjustment control unit 131A determines that the influence of the disturbance fluctuation on the response signal b2 is small, and ends the disturbance fluctuation determination.

  A predetermined range of the phase difference fluctuation range will be described.

  Even after the loop gain has converged to some extent by repeating the loop gain adjustment, a variation due to the influence of disturbance can be seen by looking at only one loop gain adjustment result. There is a correlation between the variation range and the phase difference fluctuation range, and the predetermined range of the phase difference fluctuation range can be obtained by experiments, simulations, or the like.

  It can be said that the influence of the disturbance fluctuation on the response signal b2 is small when the variation of one loop gain adjustment result is within an allowable range for the required use and performance. Therefore, the predetermined range of the phase difference fluctuation range is determined to be a range corresponding to the allowable range of this variation. The predetermined range of the phase difference fluctuation range may be determined in advance by an experiment, simulation, or the like, and set in the phase difference fluctuation determination unit 138 in advance.

  If the phase difference fluctuation range is outside the predetermined range in step S1209, the automatic adjustment control unit 131A determines that the influence of the disturbance fluctuation on the response signal b2 is large, and proceeds to step S1210. In step S1210, the automatic adjustment control unit 131A outputs a signal for changing the frequency of the reference signal b1 to the reference signal generation unit 132A. Further, the automatic adjustment control unit 131A changes the setting (center frequency) of the BPF 135A and the target phase difference in the loop gain adjustment so as to correspond to the changed frequency of the reference signal b1, and clears the stored phase difference data b3. And it returns to step S1201 and repeats the process from step S1201.

  The above is the disturbance fluctuation determination operation in the present embodiment.

  As described above, in this embodiment, the phase difference measurement between the reference signal b1 and the response signal b2 is continuously repeated before the loop gain automatic adjustment, and the frequency of the reference signal b1 is large when the phase difference fluctuation range between the measurements is large. To change. In this embodiment, by this operation, in the loop gain automatic adjustment, the frequency of the reference signal b1 can be set to a frequency with less disturbance fluctuation that deteriorates the gain adjustment accuracy, and a more accurate loop gain adjustment result is obtained. be able to.

  Note that the method of further reducing the influence of disturbance fluctuations applicable to the present invention is not limited to the technique of avoiding frequencies where there are large disturbance fluctuations, as described in the present embodiment. For example, if there is no problem such as saturation or non-linearity in the closed loop circuit, a method of improving the signal / noise ratio (S / N ratio) in the response signal b2 by increasing the amplitude of the reference signal b1 to be supplied may be used. .

(Third embodiment)
A third embodiment of the present invention will be described below with reference to the drawings. The third embodiment of the present invention is different from the second embodiment in that an amplitude variation width is calculated and a disturbance variation determination operation is performed. Therefore, in the following description of the third embodiment, only differences from the second embodiment will be described, and those having the same functional configuration as the second embodiment will be used in the description of the second embodiment. The same reference numerals as those used are assigned, and the description thereof is omitted.

  FIG. 13 is a diagram illustrating the configuration of the gain adjustment device 100B of the third embodiment. The gain adjustment device 100B of the present embodiment includes a loop gain automatic adjustment unit 130B.

  The loop gain automatic adjustment unit 130B of this embodiment includes an amplitude fluctuation determination unit 139 instead of the phase fluctuation determination unit 138 of the loop gain automatic adjustment unit 130A described in the second embodiment.

  The amplitude fluctuation determination unit 139 detects the zero cross point for the response signal b2 in the disturbance fluctuation determination operation, and sets the interval between two consecutive zero cross points as one section, and the maximum in the section where the amplitude of the response signal b2 is positive for each section. The minimum value is measured in the negative interval (see FIG. 14). Then, the absolute value of the maximum value and the absolute value of the minimum value of the measured amplitude are stored. Then, the amplitude fluctuation determination unit 139 calculates an amplitude fluctuation width that is a difference between the maximum value and the minimum value for the stored absolute value after the predetermined number of times of amplitude measurement, and the amplitude fluctuation width is within a predetermined range. And the determination result is output to the automatic adjustment control unit 131A.

  In this embodiment, when the amplitude fluctuation range is within the predetermined range, it is determined that the disturbance fluctuation is within the predetermined range. When the amplitude fluctuation range is outside the predetermined range, it is determined that the disturbance fluctuation is outside the predetermined range. To do. That is, in the present embodiment, the amplitude fluctuation determination unit 139 plays the role of disturbance fluctuation determination means.

  FIG. 14 is a diagram for explaining measurement of amplitude fluctuations by the amplitude fluctuation determination unit 139. In FIG. 14, the maximum value or the minimum value of the amplitude is indicated as ampl (n), and the absolute value of the minimum value of the amplitude or the absolute value of the maximum value is indicated as (| ampl (n) |).

  Here, disturbance fluctuation and amplitude fluctuation of the response signal b2 will be described with reference to FIG. FIG. 15 is a diagram illustrating a waveform of the response signal b2 when the reference signal b1 is continuously supplied. However, the response signal b2 includes a fluctuation disturbance that cannot be sufficiently attenuated by the BPF 135A, and is a sine wave having a reference signal frequency fsin = 32.55 [Hz] and a disturbance fluctuation frequency fn = 30 [Hz]. The thick solid line shown in FIG. 15 shows the waveform of the response signal b2 when the amplitude of the disturbance fluctuation included in the response signal b2 is 30% of the response amplitude of the reference signal b1. The thin solid line shown in FIG. 15 shows the waveform of the response signal b2 when the amplitude of disturbance fluctuation included in the response signal b2 is 10% with respect to the response amplitude of the reference signal b1.

  According to FIG. 15, it can be seen that the larger the disturbance fluctuation is with respect to the response of the reference signal b1, the larger the amplitude fluctuation of the response signal b2. If the amplitude variation of the response waveform b2 is large, it can be said that the variation of the phase difference measured in the loop gain adjustment is also large.

  Hereinafter, the disturbance fluctuation determination operation of the present embodiment will be described with reference to FIG. FIG. 16 is a flowchart for explaining a disturbance variation determination operation in the third embodiment.

  When the disturbance variation determination operation is started in the loop gain automatic adjustment unit 130B, the process proceeds to step S1601. In step S1601, the reference signal generation unit 132A and the addition unit 133 supply the reference signal b1 for a predetermined period to the closed loop circuit in order to wait until the BPF 135A is settled.

  Progressing to step S1602 following step S1601, n is initialized by setting the amplitude measurement count to n. Progressing to step S1603 following step S1602, the reference signal generation unit 132A starts supplying the reference signal b1 for a predetermined period. In FIG. 16, the predetermined period of the reference signal b1 is indicated as Nchn.

  Progressing to step S1604 following step S1603, the amplitude variation determination unit 139 measures the maximum value or the minimum value of the amplitude for each section of the response signal b2. When the amplitude measurement is completed in step S1604, the process proceeds to step S1605, and the amplitude variation determination unit 139 stores the absolute value (| ampl (n) |) of the measurement result.

  Following step S1605, the process proceeds to step S1606, the amplitude measurement count is incremented by 1 (n = n + 1), and the process proceeds to step S1607. In step S1607, the amplitude variation determination unit 139 determines whether the amplitude measurement has been performed a predetermined number of times (2 × Nchn times).

  In step S1607, when the amplitude measurement has not been executed a predetermined number of times, the process returns to step S1604, and the processes after step S1604 are repeated.

  If amplitude measurement has been performed a predetermined number of times in step S1607, the process proceeds to step S1608. In step S1608, the amplitude fluctuation determination unit 139 calculates an amplitude fluctuation width that is a difference between the maximum value and the minimum value of the amplitude measurement result of each section stored in step S1605, and the amplitude fluctuation width is within a predetermined range. It is determined whether or not. Then, the amplitude fluctuation determination unit 139 outputs the determination result to the automatic adjustment control unit 131A.

  The predetermined range of the amplitude fluctuation range is determined in the same manner as the predetermined range of the phase difference fluctuation range described above. That is, it is determined in a range corresponding to a variation in the result of one loop gain adjustment. The predetermined range of the amplitude fluctuation range may be determined in advance by an experiment, simulation, or the like and set in the amplitude fluctuation determination unit 139 in advance.

  If the amplitude fluctuation range is within the predetermined range in step S1608, the automatic adjustment control unit 131A determines that the influence of the disturbance fluctuation on the response signal b2 is small, and ends the disturbance fluctuation determination operation.

  If the amplitude fluctuation range is outside the predetermined range in step S1608, the automatic adjustment control unit 131A determines that the influence of the disturbance fluctuation on the response signal b2 is large, and proceeds to step S1609. In step S1609, the automatic adjustment control unit 131A outputs a signal for changing the frequency of the reference signal b1 to the reference signal generation unit 132A. Further, the automatic adjustment control unit 131A changes the setting (center frequency) of the BPF 135A and the target phase difference in the loop gain adjustment so as to correspond to the changed frequency of the reference signal b1, and clears the stored phase difference data b3. Then, the process returns to step S1601, and the processing from step S1601 is repeated.

  The above is the disturbance fluctuation determination operation of this embodiment. Note that the disturbance fluctuation determination operation of the present embodiment is also performed before the loop gain automatic adjustment is performed, as in the second embodiment.

  As described above, in the present embodiment, the amplitude measurement of the response signal b2 is repeatedly performed before the loop gain automatic adjustment is performed, and the frequency of the reference signal b1 is changed when the amplitude fluctuation range for each period is large. In this embodiment, with this operation, in the loop gain automatic adjustment, the frequency of the reference signal b1 can be set to a frequency with less disturbance fluctuation that deteriorates the gain adjustment accuracy, and an accurate loop gain adjustment result can be obtained.

  As mentioned above, although this invention has been demonstrated based on each embodiment, this invention is not limited to the requirements shown in the said embodiment. With respect to these points, the gist of the present invention can be changed without departing from the scope of the present invention, and can be appropriately determined according to the application form.

It is a figure explaining the composition of gain adjustment device 100 of a first embodiment. 2 is a diagram illustrating a configuration of a servo calculation unit 120. FIG. It is a figure explaining the phase difference measurement by the phase difference measurement part 136. FIG. 6 is a first flowchart illustrating the operation of the loop gain automatic adjustment unit 130. 12 is a second flowchart illustrating the operation of the loop gain automatic adjustment unit 130. It is a figure which shows the frequency characteristic and target phase difference of the closed loop circuit in 1st embodiment. It is the figure which showed the waveform of the reference signal b1 and the response signal b2. FIG. 8 is a diagram showing a result of measuring the phase difference shown in FIG. 3 in the waveform of FIG. 7. It is a figure explaining the influence which disturbance fluctuation actually has on loop gay automatic adjustment. It is a figure explaining the structure of 100 A of gain adjustment apparatuses of 2nd embodiment. It is a figure which shows a result when a reference signal is supplied continuously and a phase difference is measured for every period. It is a flowchart explaining the disturbance fluctuation | variation determination operation | movement in 2nd embodiment. It is a figure explaining the structure of the gain adjustment apparatus 100B of 3rd embodiment. It is a figure explaining the measurement of the amplitude fluctuation | variation by the amplitude fluctuation | variation determination part 139. FIG. It is a figure which shows the waveform of the response signal b2 when the reference signal b1 is supplied continuously. It is a flowchart explaining the disturbance fluctuation | variation determination operation | movement in 3rd embodiment.

Explanation of symbols

100, 100A, 100B Gain adjustment device 110 Speed error detection unit 120 Servo calculation unit 130, 130A, 130B Loop gain automatic adjustment unit 131, 131A Automatic adjustment control unit 132, 132A Reference signal generation unit 133 Addition unit 134 Correction gain 135, 135A BPF (band pass filter)
136 Phase difference measurement unit 137, 137A Gain change unit 138 Phase difference variation determination unit 139 Amplitude variation determination unit

Claims (7)

A phase difference between a reference signal having a predetermined frequency supplied to the closed loop circuit and a response signal extracted at a position that makes a round of the closed loop circuit from a position where the reference signal is input is measured, and the phase difference is determined as a predetermined target. A gain adjusting device for adjusting a loop gain of the closed loop circuit so as to approach a value;
A calculation means for calculating a loop gain value that brings a phase difference close to a predetermined target value each time the loop gain is adjusted;
Changing means for changing the value of the loop gain of the closed loop circuit,
The changing means is
After the loop gain adjustment is performed a plurality of times, the gain adjustment is performed such that the loop gain value of the closed loop circuit is changed to an average value of the loop gain values calculated by the calculation means each time the loop gain is adjusted. apparatus. In the multiple loop gain adjustments, the number of loop gain values used to determine the average value is:
The gain adjusting apparatus according to claim 1, wherein the gain is a value obtained by dividing the frequency of the reference signal by an absolute value of a difference between the frequency of the reference signal and the frequency of disturbance fluctuation included in the response signal. Disturbance fluctuation that determines whether or not the magnitude of disturbance fluctuation included in the response signal is within a predetermined range based on the reference signal supplied for a plurality of periods and the response signal extracted for each period Having a judging means,
The gain adjusting apparatus according to claim 1 or 2, wherein the reference signal generating unit changes the frequency of the reference signal when it is determined that the disturbance fluctuation is not within a predetermined range. The disturbance fluctuation determining means includes
When the phase difference fluctuation range, which is the difference between the maximum value and the minimum value of the phase difference between the reference signal and the response signal for each period, is not within a predetermined range, it is determined that the magnitude of the disturbance fluctuation is not within the predetermined range. The gain adjusting device according to claim 3. The disturbance fluctuation determining means includes
The determination that the magnitude of the disturbance fluctuation is not within a predetermined range when an amplitude fluctuation width that is a difference between the maximum value and the minimum value of the amplitude of the response signal extracted for each period is not within the predetermined range. 3. The gain adjusting device according to 3. A phase difference between a reference signal having a predetermined frequency supplied to the closed loop circuit and a response signal extracted at a position that makes a round of the closed loop circuit from a position where the reference signal is input is measured, and the phase difference is determined as a predetermined target. A gain adjustment method by a gain adjustment device that adjusts the loop gain of the closed loop circuit so as to approach a value,
Each time the loop gain is adjusted, a calculation procedure for calculating a loop gain value that brings the phase difference close to a predetermined target value;
A change procedure for changing the value of the loop gain of the closed loop circuit,
The change procedure is as follows:
After the loop gain adjustment is performed a plurality of times, the gain adjustment is performed such that the loop gain value of the closed loop circuit is changed to the average value of the loop gain values calculated by the calculation procedure every time the loop gain is adjusted. Method. A phase difference between a reference signal having a predetermined frequency supplied to the closed loop circuit and a response signal extracted at a position that makes a round of the closed loop circuit from a position where the reference signal is input is measured, and the phase difference is determined as a predetermined target. A gain adjustment program executed in a gain adjustment device that adjusts the loop gain of the closed loop circuit so as to approach a value,
In the gain adjusting device,
A calculation step of calculating a loop gain value that brings the phase difference close to a predetermined target value each time the loop gain is adjusted;
Changing the loop gain value of the closed loop circuit, and
The changing step includes
After the loop gain adjustment is performed a plurality of times, the gain adjustment is performed such that the loop gain value of the closed loop circuit is changed to an average value of the loop gain values calculated by the calculation step every time the loop gain is adjusted. program.

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